Summary on Urinary Stone Management

1. Stone management
Edmond

2. Workup
• Imaging
• Renal fxn scan
• Metabolic workup: Bld & Urine
• Txn of metabolic stone

3. Review of modality of stone txn
• ESWL
• URSL
• PCNL
• Lap/open renal stone surgery
• Lap/open ureteric stone surgery
• Dissolution therapy

4. Treatment of Renal stone
• Staghorn stone
• Upper and mid pole stone Lower pole stone
• Renal pelvis stone with upper ureter extension
• Calyceal stone
• Horsehoe kidney stone
• Pelvic kidney stone
• Bilateral renal stone
• Stone with PUJO

5. Treatment of ureteric stone
• Mx of renal colic
• Relief obstruction
• Ureteric stone: upper , mid , lower
• MET
• Bilateral ureteric stone

6. EpidmiologyEpidmiology
• Epidemiology Caucasian of renal stone – 10%, rising trend
• Recurrence of renal stone within 1 year – 10%
• Recurrence of renal stone within 10 years – 50%
• Calcium stone - 75% : Ca oxalate , Ca phosphate
• Non-calcium stone – 25%
– Infection stone
• Magnesium ammonium phosphate (10%)
• Carbonate apatite
• Ammonium urate
– Ammonium urate stones form when a urease-producing infection
occurs in patients with urine that is supersaturated with uric
acid/urate
– Uric acid (10%) : 20% of gout have uric acid stone
– Rare stone that is radiolucent : Indinavir (HIV med), triamterene (K
sparing diuretic)
– Cystine stone (renal tubular defect – 1%)

8. Risk factorsRisk factors

9. Why does the stone form?
• Imbalance between stone promoter and inhibitor
– Saturation below solubility product  stone will not form
– Saturation above solubility product  crystal growth can be
prevented by increased inhibitors
– Saturation above formation product  stone forms despite
inhibitors
• Urine concentration btw solubility product & formation
product  metastable
• Urine concentration above formation product 
supersaturated
• Inhibitor of crystallization : Mg , GAG, Tamm-Horsfall (?)
protein, citrate

10. • Phases of stone formation:
– Nucleation: crystal nuclei occur on surface of
epithelial cell or on other crystal
– Aggregation : Crystal nuclei form into clumps

11. Risk factors
• Age (younger age group, peak at 40)
• Sex (male)
• Strong family history of stone formation
• Race (Caucasian > black > Asian)
• Positive family history
• Diet: obesity
– High animal protein (high ca, uric & oxalate, low pH, low citrate)
– High salt (hypercalciuria)
– High Calcium intake is protective
– Vit D (increase instestinal Ca absorption)
– Vit C (cause hyperoxaluria)
• Occupation: sedentary lifestyle
• Gout
• Low fluid intake (urine output <1L)

12. Age
Gender
Season/climate
Fluid Intake
Stress/diet
Occupation
Mobility
Metabolic disorders
Genetic disorders
Anatomical abnormality
Family history
Risk Factors for Calcium Stone-Formation

13. Urinary Risk Factors for Stone-Formation
• Low urine volume (<1L/24hrs)
• Alteration in urinary pH (<5.5,>7.5)
• Hypercalciuria (>4mg/kg/24hrs)
• Hyperoxaluria (40mg/24hrs)
• Hyperuricosuria (>600mg/24hrs)
• Hypocitraturia (<250mg/24hrs)
• Hypomagnesiuria (<50mg/24hrs)

14. What are the risk factors forWhat are the risk factors for
recurrent stone formation?recurrent stone formation?
• Diseases associated with stone formation
– Hyperparathyroidism
– Renal tubular acidosis (partial/complete)
– Cystinuria
– Primary hyperoxaluria
– Jejuno-ileal bypass
– Crohn’s disease
– Intestinal resection
– Malabsorptive conditions
– Sarcoidosis

15. What are the risk factors for
recurrent stone formation?
• Anatomical abnormalities associated with
stone formation
– Tubular ectasia (medullary sponge kidney)
– Horseshoe kidney
– Caliceal diverticulum, caliceal cyst
– Pelvo-ureteral junction obstruction
– Ureteral stricture
– Vesico-ureteral reflux
– Ureterocele

16. What are the risk factors for
recurrent stone formation?
• Medication associated with stone formation
– Calcium supplements (Normal adult - 20-50 mmol per
day)
– Vitamin D supplements
– Ascorbic acid in megadoses (> 4 g/day)
– Triamterene
– Indinavir
– (acetazolamide)
– (Sulphonamides)
– Corticosteroid (increase enteric absorption of Ca)
– Chemotherapeutic agent (uric acid)

17. What are theWhat are the OtherOther risk factorsrisk factors
for recurrent stone formation?for recurrent stone formation?
• Onset of urolithiasis early in life ( i.e.
below 25 years of age)
• Stones containing brushite (calcium
phosphate

18. ImagingImaging

19. What is the diagnostic imagingWhat is the diagnostic imaging
of choice for renal colic?of choice for renal colic?
• IVU has been the gold standard in the past
– Bowel preparation and 6-hour fasting
– KUB (preliminary film)
– Immediate nephrogram (1mg/kg Omnipaque)
– 5 mins > tomograms >
– 10 mins (compression and release in prone position) >
– 20 mins film
– Post-micturition > delay film
– Laterally visualized calyces on IVU not correspond to posterior row of
calyces
– Abdominal compression during IVU is not necessary for child under 2
• The specificity and sensitivity of unenhanced helical CT
was found to be similar or superior to that obtained with
IVU

20. What are the advantages andWhat are the advantages and
disadvantages of IVU?disadvantages of IVU?
• Advantages
– Road map for percutaneous procedure, clear calyceal / ureter
anatomy, better function information
– For emergency on table IVU - use double strength contrast
(2mg/kg)
– Less radiation(2.5mSv)
– Specificity – 90%
• Disadvantages
– contrast nephropathy, allergy to contrast (mortality 1/1 million)
– Can only see 90% stone (miss radiolucent stone)
– Time consuming
– Low sensitivity (60%)

21. What are the signs ofWhat are the signs of
obstruction on IVU?obstruction on IVU?
• Cause delayed dense nephrogram
• Clubbing of calyces
• Dilated renal pelvis/ureter
• Hold up of contrast
• Normal IVU during pain cannot rule out
ureteric obstruction as cause

22. What are the advantages andWhat are the advantages and
disadvantages of NCCT?disadvantages of NCCT?
• Advantages
– No contrast,
– demonstration of radiolucent uric acid & xanthine
stone
– Show alternative diagnosis, relationship with extra
renal organ
– ~100% sensitivity and specificity
• Disadvantages
– Higher radiation (5mSv)
– Less clear calyceal anatomy
– Less suited for follow-up after the treatment of
radiopaque stones
– Cannot see indinavir stone
• Greenwell et al, British study

23. What are the signs ofWhat are the signs of
obstruction on CT?obstruction on CT?
• Hydronephrosis
• Increased renal size
• Perinephric or periureteric stranding
• Ureteric wall edema (rim sign)

24. How about KUB?
• NCCT should be the initial imaging examination
for acute ureteric colic
• preliminary KUB X-ray is unjustified
– All stones visible on scout also seen on KUB
– Reduce radiation and cost
• KUB after +ve CT for Rx and F/U decisions
– If stone visible on scout  no need for KUB
– If NOT visible on Scout  Perform KUB X-ray
• ~ 1/3 will show a radio-dense stone
• KUB still is required in the planning of treatment
for urolithiasis.

25. What are the advantages andWhat are the advantages and
disadvantages of USG?disadvantages of USG?
• Advantages
– No radiation/contrast , cheap, accessible, radiolucent
stone
– Should be considered the first imaging test in children
with suspected urolithiasis
– (In child, renal cortex appear bright on US)
– Sensitivity – 80%, specificity – 95%
• Disadvantages
– No road map, operator dependant, difficult or unable
to visualize mid-distal ureter

26. What is the diagnostic imagingWhat is the diagnostic imaging
of choice for renal colic?of choice for renal colic?
KUB combined with US. Extensive experience shows that in a large proportion of
patients these methods are sufficient for the diagnosis of a ureteral stone
Sensitivity of KUB – 50%, specificity – 70%

27. What are the radiologicalWhat are the radiological
feature of stones?feature of stones?

28. What are the important issuesWhat are the important issues
of IV contrast?of IV contrast?
• Classified into ionic vs non ionic and low/ high or iso-
osmolar
• High osmolar - more nephrotoxic
• The most commonly used contrast media are the
nonionic low osmolar which are still hypertonic with an
osmolarity of about 600 mosmol/l eg omnipaque
• The only iso-osmolar contrast in clinical use is the
visipaque
• Contrast media have a half life of 1 hour in the body and
by 12 hours 90% is excreted by the kidneys

29. What are the precautions for those at riskWhat are the precautions for those at risk
of contrast allergyof contrast allergy??
• Asthma (6X for low osmolar, 10X for high
osmolar)
– Alternative Ix
– Defer Ix if poor control
– Standby emergency drugs box
• Always use low-molecular non-ionic contrast
medium
• Give a corticosteroid (e.g. prednisolone, 30 mg)
between 12 hours and 2 hours before the
contrast medium is injected

30. What is the risk of metformin ofWhat is the risk of metformin of
contrast injection?contrast injection?
• Metformin which was exclusively excreted by kidney
• Precipitate lactic acidosis ~1/10000 (serum lactic acid
concentration > 5 mmol/L) in case of contrast-induced
anuria
• Lactic acidosis is associated with high mortality,
particularly when renal function is reduced
– Symptoms of lactic acidosis:
• Vomiting, somnolence, epigastric pain, anorexia,
hyperpnoea, lethargy, diarrhoea and thirst
– Treatment: Diuresis ≥ 100 ml/h during 24 hours
– Serum creatinine, lactic acid and blood pH should be
monitored +/- ICU/medical care

31. What are the precautions ofWhat are the precautions of
those taking metformin?those taking metformin?
• EAU guideline
– Serum creatinine level should be measured in every patient with
diabetes being treated with metformin
– Metformin and normal serum creatinine
• metformin stopped for 48 hours from the time of the radiological
examination until the serum creatinine remains normal
– Metformin & Reduced renal function
• metformin should be stopped 48 hours before administration of
contrast medium
• metformin may resume 48 hours after the examination provided that
serum creatinine remains at the pre-examination level
– if contrast given to patient taking metformin
• metformin stopped immediately
• hydration to ensure U/O 100ml/hr x 24 hours
• monitor serum Cr, lactic acid and blood gas

32. What is contrastWhat is contrast
nephrotoxicity?nephrotoxicity?
• Increase of 25%, or at least 44 μmol/L for Cr in 3
days following IV contrast administration
• Reduced renal perfusion and toxic effect on
tubular cells
• Direct nephrotoxic effect
• Vasoconstriction of glomerular afferent arterioles
causes a reduced GFR and increased renal
vascular resistance

33. What are the risk factors ofWhat are the risk factors of
contrast nephropathy?contrast nephropathy?
1. Increased serum creatinine
2. Dehydration
3. Age over 70 years
4. Diabetes
5. Congestive heart failure
6. Nephrotoxic drugs, (NSAIDs, aminoglycosides)
7. Multiple myeloma
8. Injection of contrast medium at intervals less than 48
hours

34. When Contrast medium should notWhen Contrast medium should not
be given, or should be avoided?be given, or should be avoided?

35. How to treat anaphylactoid reaction (notHow to treat anaphylactoid reaction (not
mediated by antibody) after IVU?mediated by antibody) after IVU?
• ABC
• Intubated if necessary
• 100% O2 mask
• BP/P monitoring
• Two large bore iv drip
• Adrenaline 0.5mg (1:1000 – 0.5ml) intramuscularly,
repeat again every 5 minutes depending on pulse and
blood pressure
• Piriton 10mg
• Hydrocortisone 200mg
• ICU care

36. What is the role of DMSA?What is the role of DMSA?
• 99mTC dimercaptosuccinic acid
• Cortical imaging
• Split renal function before planning
definitive treatment
• Actively extracted by functioning renal
tubules

37. How to prevent radiationHow to prevent radiation
hazards?hazards?
• Main slogan : ALARA  as low as reasonably achievable
• ( I ) Minimize scattering
– ( 1 ) Put the fluoroscopy beam under the table ( image intensifier
is placed superiorly ) to minimize XR leakage and scattering.
– ( 2 ) Keep the image receiver as close to the patient as
possible :
• Decrease the distance between the focal spot and the
receiver
• Decrease the fluoroscopic beam intensity
• Decrease blurring of the image
• Serve as a scatter barrier
• ( II ) Decrease fluoroscopy exposure
– ( 1 ) Decrease fluoroscopy time
– ( 2 ) Use of last image – hold feature
– ( 3 ) Collimation
• narrow the beam and limit the imaging area to the exact
position of interest

38. How to prevent radiationHow to prevent radiation
hazards?hazards?
• ( III ) Distance protection ( inverse
square law )
• ( IV ) Shielding
– Lead apron 0.5 mm thick
– Thyroid shield
– Lead glove
• ( V ) Dosage monitoring by wearing
dorsimeter

39. Specific Stone type &
underlying factors

40. Calcium Oxalate (85%)
• Hypercalciuria: 50%
– Definition: >7mmol Ca/day (men) , > 6mmol Ca/day (women)
1. Absorptive: increase intestinal absorption
2. Renal: renal leakage of calcium
3. Resorptive: increase bone demineralization (hyper PTH)
• Hypercalcaemia:
– Primary hyper PTH (1% form stone)
• Hyperoxaluria:
1. Absorptive (enteric hyperoxaluria): short bowel syndrome  colon
expose to more bile salts increase permeability of oxalate
2. Renal: renal leakage of oxalate
3. Primary hyperoxaluria: increase hepatic oxalate production
• Hypocitraturia:
– Citrate forms soluble complex with calcium , prevent binding to oxalate
• Hyperuricosuria:
– High uric acid  uric acid stone Ca oxalate form stone on its surface

41. Uric acid (5%)
• Human not able to convert uric acid to allantoin (very
soluble)
• Thus urine is supersaturate with insoluble uric acid
• Uric acid exits as 2 form in urine:
– Uric acid : insoluble
– Sodium urate: 20x more soluble in alkaline pH
• Human urine is acidic (metabolic product are acid)
• Thus low urine pH predispose to uric acid stone
formation
• 20% pt with gout have uric acid stone
• 20% with uric acid stone have gout
• 1% per year risk of stone formation after first gout attack
• Myeloproliferative disease:
– Txn with cytotoxic drug  cell necrosis large amount of
nucleic acid  convert to uric acid  plug in collective system
• Txn: Alkalinization of urine

42. Ca phosphate (10%)
• Occur in patient with Renal tubular acidosis (RTA)
• Defect of renal H+ secretion  urine alkaline +
metabolic acidosis
• High urine pH increase supersaturation of Ca and
Phosphate
• Type 1 RTA (distal) :
– Failure of distal renal tubule to acidified urine
– 70% type RTA form stone
– Urine pH >5.5 , low citrate , hypercalciuria
– Bld: metabolic acidosis, hypo K
• If urine pH > 5.5: use ammonium chloride loading test
– If urine pH remain > 5.5  incomplete distal RTA
• Txn: acidified urine

43. Struvite stone
• Magenesium , ammonium & phosphates
• Urease-producing bacteria which convert
• Urea  Ammonium + CO2
• Alkalinized urine
• Txn: acidified urine
• Urease producing bacteria:
1. Proteus
2. Klebsiella
3. Serratia
4. Pseudomonas
5. Providencia
6. Staphylococcus, ureaplasma urealyticum

44. Cystine stone
• Autosomal-recessive
• Disorder of transmembrance cystine transport
• amino acids cystine, ornithine, lysine, and arginine, (“COLA”)
• Result in decrease absorption of cystine from intestine and proximal
tubule of the kidney
• About 3% of adult stone formers are cystinuric and 6% of stone-
forming children
• Cystine stones are relatively radiodense because they contain sulfur
atoms
• Cystinuria  urine supersaturate with cystine
• Cystine is poorly soluble in acid urine
• Dx: Cyanide-nitroprusside colorimetric test (cystine spot test)  if
+ve  24 hour urine collection
• 24hr cystine >250mg  cystinuria
• Txn: alkalinization of urine

45. Xanthine stone
• Rare
• Like other purine stones they are radiolucent and can be
confused for uric acid stones
• Xanthine oxidase deficiency is autosomal recessive
• Half of the homozygotes are asymptomatic
– Only biochemical evidence of lower serum uric acid levels and
high urinary excretion of xanthine
• Xanthine oxidase converts hypoxanthine to xanthine and
then to uric acid
• Allopurinol inhibits xanthine oxidase and in high doses it
can precipitate xanthine stones (eg treatment of Lesch
Nyhan syndrome)
• Xanthine is less soluble than hypoxanthine and hence
the latter does not tend to precipitate

48. Analysis of stoneAnalysis of stone
compositioncomposition

49. What are the methods of
analysis of stone composition?
• Polarizing microscopy
• X-ray crystallography
• Infrared spectroscopy
– All patients should have at least one stone
analysed
– Repeated analysis when any changes in urine
composition, as a result of medical treatment,
dietary habits, environment or diseases, might
have influenced stone composition

50. Analyses inAnalyses in
uncomplicated stoneuncomplicated stone
diseasedisease

51. What is diagnostic evaluation forWhat is diagnostic evaluation for
single stone formers?single stone formers?
• History, P/E
• Medications
• Fluid intake
• Biochemical screen
– U&E, Ca,PO4, uric acid, bicarbonate
• PTH if Ca is elevated
• Urine
– C/ST
– PH>7.5 Infected stones
– PH<5.5 Uric acid
– Sediment for crystalluria
– Urine culture –urea splitting organisms
– Cystine test
• Xray
• Stone analysis

52. Biochemical Investigation
• A bottle with HCL solution is used to measure
calcium oxalate, phosphate, citrate and Mg
• A plain bottle is used to estimate uric acid
• TWO 24-hor urine collections for each set of
analyses recommend
• Collecting bottles:
– 5% Thymol in isopropanol (10ml for a 2-L blt) or
– Stored at < 8 degree
• Fasting morning spot urine sample should be
analysed
• A spot urine sample can provide a rough guide
to the need of further analyses

53. Analyses inAnalyses in
complicated stonecomplicated stone
diseasedisease

54. Indications for metabolic stoneIndications for metabolic stone
evaluationevaluation
• Recurrent stone formers
• Strong family history of stones
• Intestinal disease (chronic diarrhea)
• Pathologic skeletal #, osteoporosis
• History of UTI with calculi
• Gout
• Solitary kidney
• Anatomical abnormalities
• Renal insufficiency
• Stones composed of cystine, uric acid or struvite

55. Evaluation of stone formers 1Evaluation of stone formers 1
• History
– Underlying predisposing conditions
– Medications (Ca, Vit C, Vit D, steroids)
– Fluid intake, meat consumption

56. Evaluation of stone formers 2Evaluation of stone formers 2
• Blood screen
– Sodium, potassium, Calcium, uric acid
– Creatinine
– Parathyroid hormone
• Urine analysis
– pH (>7.5 infection, <5.5 uric acid)
– Culture
– Microscopy for crystals
– 24 hr urine: Ca, oxalate, uric acid, citrate, pH, cystine, total
volume
– MSU : rule out infection
• Stone analysis

57. What are the summary of analyses in
patients with uncomplicated and
complicated stone disease?
Patients should be advised to discard the first
void urine sample and start collecting urine from
there on including the first voided urine sample of
the following morning

61. Hypercalciuria: >200mg/dayHypercalciuria: >200mg/day
• Absorptive: ↑intestinal absorption  decreased PTH
 normal serum calcium
– Type I – not responded to Ca restriction
– Type II – responded to Ca restriction
• Renal (also known as renal leak)
- High urinary Ca  increased PTH  normal serum
calcium
• Resorptive:
1. hyperPTH: excessive PTH excessive bone resorption 
increase renal synthesis of Vit D increase intestinal
absorption of Ca  hypercalcemia
2. Malignancy associated hypercalcemia
3. Glucortocoid induced hypercalciuria

64. Hyperoxaluria (urinary oxalate >Hyperoxaluria (urinary oxalate >
40mg/day)40mg/day)
• Increased urinary saturation Calcium
oxalate
• Causes
– Primary (deficiency liver enzyme > early renal
failure > renal and liver transplant)
– Enteric (chronic diarrhoea with fat
malabsoption increase oxalate
reabsorption, eg Bowel resection, IBD )
– Dietary: chocolate, spinach, nuts, strawberry,
tea and ascorbic acid

65. Hypocitraturia (<250mg/day)Hypocitraturia (<250mg/day)
• Citrate is an important inhibitor that can reduce Ca stone
formation
– Metabolic acidosis reduces urinary citrate levels (due
to enhanced renal tubular reabsorption and reduced
synthesis of citrate)
– Renal tubular acidosis, chronic diarrhoeal states
(cause intestinal alkali loss), excessive animal
protein, thiazide diuretics (hypoK and intracellular
acidosis)
– RCT showed K citrate supplement in hypocitraturia
Caoxalate stone remission rate 70% VS 20% in
placebo
• Contraindicated in active peptic ulcer disease /
hyperkalemia / Cr > 2.5mg/dl

66. Low Urine pH (<5.5)Low Urine pH (<5.5)
– Risk factor for both uric acid and Ca oxalate
stone
– Undissociated form of uric acid serve as
nidus for calcium oxalate stones through
heterologous nucleaton
– Acidosis increases bone resorption and
produces renal calcium leak

67. Hyperuricosuria (urinary uricHyperuricosuria (urinary uric
acid >600mg/day)acid >600mg/day)
– Uric acid reduces effectiveness of urinary
inhibitors of crystallization promote Ca
oxalate formation
– Increased dietary purine intake, gout,
myeloproliferative and lymphoproliferative
disorder, multiple myeloma, hemolytic
disorders and increased insulin (decreased
urine pH)

68. Uric acid stoneUric acid stone
• 3 main determinants
– Low pH
– Low urine volume
– Hyperuricosuria

69. Uric acid stoneUric acid stone
• Low urine pH
– Most important factor (most patients have
normal uric acid level but invariably have low
urine pH)
– at pH 5, even modest amount of uric acid
exceed solubility
– Low pH increases concentration of sparingly
soluble undissociated uric acid direct
precipitation of uric acid

70. What is cystinuria?What is cystinuria?
• Autosomal recessive
• Type A (chromosome 2), Type B (chromosome 19) type AB
• Associated with defective renal absorption of cystine, ornithine,
lysine , arginine (COLA), only cystine insoluble
• 1% of all renal stones
• The incidence of homozygous cystinuria is 1/20,000 and
heterozygous 1/20 to 1/200
• Median age of 20-30
• The 24 hour urine excretion of normal cystine is <80mg
• In homozygous cystinurics that quantity is >600 mg/day,
heterozygotes > 400mg/day
• Cystine stones commonly form in homozygous cystinurics but
heterozygous cystinurics can form renal stones which may well not
be cystine stones
• Cystione stones >4mm will normally be radioopaque due to their
disulphide bonds
• Ground-glass appearance and hexagonal crystal in microscopy

71. What is Brand’s test?What is Brand’s test?
• Qualitative test for detecting cystine in urine
>75mg/l
• Spot test for cystinuria
• 12 drops of Na cyanide are added to the urine
sample to stain the urine pinkly
• Cyanide converts cystine to cysteine which
binds nitroprusside causing purple
• False positive results may occur in
homocystinuria or acetonurina, sulpha drugs,
ampicillin or N-acetylcysteine

72. What is the treatment forWhat is the treatment for
cystine stone?cystine stone?
• Diet: low in methionine, Na < 2g/day
• Drinking: 24 hour urine > 3L
• Drug:
– Potassium Citrate: 20-25 mmol/day TDS
– Complex formation by chelating agents:
– Thiol compounds: Vit B6 50mg QD together
• D-penicillamine (1-2g/day)
• Alfa- mercaptopropionyl glycine (tiopronin) 750mg/day)
– Captopril : 75-100mg QD
• Accompanied by pyridoxine to avoid vitamin B6
deficiency
• Regular urine protein to detect nephrotic syndrome
caused by penicillamine or mercaptopropionyl glycine

73. What is the medical treatment for
cystine stone?

74. Renal tubularRenal tubular
acidosisacidosis

75. Child presents with stunted growth
• What is the diagnosis? (1)
• What is the physiological abnormality in this child? (1)
• Name the metabolic abnormality (1)
• What is the usual urine pH? (1)
• What is the usual component of stone formation? (1)
Q59

76. • KUB : bilateral medullary nephrocalcinosis
• Dx : RTA type 1 (1)
• Inability to excrete acid from collecting duct
despite metabolic acidosis (1)
• Hypokalemic, hyperchloremic, non—anion
gap metabolic acidosis (1)
• Elevated urine pH (>6.0), hypercalciuria,
hypocitraturia (1)
• Calcium phosphate (1)

77. Renal Tubular AcidosisRenal Tubular Acidosis
• Syndromes of metabolic acidosis resulting from defects in tubular hydrogen secretion
and urinary acidification
• RTA I –
– The most common form of RTA
– Thee majority of patients are females (80%) and 70% of them will form stones
– Failure of H+
secretion in the distal nephron
– Metabolic acidosis promotes bone demineralisation : secondary
hyperparathyroidism, hypercalciuria hypocitraturia, coupled with high urine pH =>
calcium phosphate stones
– Usually occurs in adults : typical bilateral medullary nephrolithiasis
– Children : vomiting, failure to thrive, growth retardation
– Primary : idiopathic, hereditary (autosomal dominant or autosomal recessive),
sporadic
– Secondary : autoimmune diseaese, Sjogren’s syndrome, SLE
– Tx: Sodium bicarbonate
Potassium citrate

78. • RTA II -
– Due to Failure of bicarbonate reabsorption in the proximal tubule
– Associated with generalised defect in proximal tubule function
eg. reabsorption of phosphate, urate
– Associated with other absorptive deficiencies (Fanconi’s
syndrome)
– Do not tend to form stones due to increase urinary citrate.
– Metabolic acidosis leads to growth retardation and hypokalemia
• RTA IV –
– Impairment of cation exchange in the distal tubule, reduced
secretion of H+
and K+
.
– The unique feature is hyperkalemia
– Associated with underlying aldosterone deficiency or resistance
– Clinically associated with chronic renal damage such as diabetic
nephropathy / interstitial renal disease
– Renal stone formation uncommon as excreted substrates eg. Ca
and urate decreased due to impaired GFR

79. What are some parameters to raiseWhat are some parameters to raise
suspicious of renal tubular acidosis ?suspicious of renal tubular acidosis ?
• Hypokalaemia hyperchloremic metabolic acidosis,
increased urine K and Na, hypocitraturia, hypercalciuria
from resorption of bone, hyperphosphaturia
• Calcium phosphate stone
• If pH above 5.8 in fasting morning urine = complete RTA
• If urine pH is >5.8, confirmed by the ammonium chloride
loading test (oral 0.1g/kg = acid load). Urine pH that
remains above 5.8 after an oral dose of ammonium
chloride = incomplete RTA

80. (What are the analytical findings in
patients with complete or incomplete
distal renal tubular acidosis?)

81. ESWL

82. 4 factors of ESWL
• Energy source
• Coupling
– System to transmit shockwave to decrease
energy loss
• Focusing
– Acoustic lens
– Cylindrical reflector
• Imaging
– USG, fluoroscopy or both

83. Generator type
• Electrohydraulic lithotripsy (EHL)
– Spark is produced between two electrodes under water, which
results in the rapid expansion and collapse of a gas bubble and
subsequent energy transmission
– A metal hemi-ellipsoid reflector is used to focus the energy
– Result in great shot-to-shot variability as electrode wear down
• Electromagnetic lithotripsy
– Cylindrical electromagnetic source, and energy is focused by an
acoustic lens
• Piezoelectric lithotripsy
– Piezoelectric materials consist of ceramic or crystal elements
(barium titanate) that produce an electrical discharge under
stress or tension, or can be induced to rapidly expand by the
application of a high-voltage pulse.
– The piezoelectric elements are placed on the inside of a
spherical dish to permit convergence of the shock front
• For EM & PE  acoustic output instability may occur

84. 1. Electrohydraulic
2. Electromagnetic
3. Piezoelectric

85. Shock wave
• What is shock wave?
• A short-duration (<10us)
acoustic pressure wave
consist of a compressive
phase & a tensile phase
• Compressive phase: initial
short and steep compressive
front with peak pressures of
about 40 MPa (megapascals)
• Tensile phase: longer, lower
amplitude negative (tensile)
pressure of 10 MPa,
• Note that the ratio of the
positive to negative peak
pressures is approximately 5

86. Newer generator
• Higher peak pressure (more effective?)
• Small focal zones (less painful)
• Ideal for txn of ureteral stone
• No observe improvement in SFR
• F1: electrode (focus of an ellipsoid)
• F2: target (kidney stone)

87. Dual Heads
• SW generated simultaneously from 2
reflectors through 2 axes in non-opposinig
directions to the same F2
• Intensifies and localizes cavitational
effects
• Better quality and rate of stone
disintegration

88. Electroconductive
4th generation
• Electrode surround by highly conductive
solution
• Shock generation by discharge between anode
and cathode
• Repeatable spark location due to shorter
interelectrode distance and reduced electrode
wear (vs EHL)
• Electrode life time > 40000 impulses
• spark generation exactly at F2

89. Electroconductive
• Efficacy of the lithotripter
• Latest-generation lithotripters are at least as effective as
the first lithotripters, but are much cheaper and have
greater versatility
• 4th generation: Sonolith
– Electroconductive
– Large focal diameter of the SW (12.8–25 mm)
– A longer pulse duration (138–279 ns)
– A relatively lower peak pressure
– Achieved a high success rate, comparable with that
using the HM-3 machine but with lower analgesia
requirements and very low re-treatment rates

90. ECL vs EHL
• Reduction in shockwave pressure variability
• Improved energy transfer to the stone
• Linear relation between the voltage setting and
the pressure at F2  stone Fragmentation
• Result Tolley
–Sonolith between 2004 and 2006
–plain KUB and USG at 1 and 3 months
–SFR:
–77% (<10mm), 69% (11-20mm), 50% (>20mm)
–74% (lower), 70% (upper), 78.5 (middle), 74% (renal pelvis)

91. Mechanism of stone comminutionMechanism of stone comminution
• Stone communition is a progressive process consisting:
– Initial (base of dynamic squeezing) propagation
– And colaescence (because of increasing fragility)
– Mechanical stress produce micro-cracks  sudden break off of the calculus
• Spallation ( 剝落 )
– Once the shockwave enters the stone, it will be reflected at sites of
impedance mismatch. One such location is at the distal surface of the
stone at the stone-fluid (urine) interface
– As the shockwave is reflected, it is inverted in phase to a tensile
(negative) wave. If the tensile wave exceeds the tensile strength of the
stone, there is an induction of nucleation and growth of microcracks that
eventually coalesce, resulting in stone fragmentation
• Cavitation ( 氣穴 )
– During the negative pressure wave, the pressure inside the bubble falls
below the vapor pressure of the fluid, and the bubble fills with vapor and
grows rapidly in size (almost three orders of magnitude). As these
bubbles grow, they oscillate in size for about 200 μs and then collapse
violently, giving rise to high pressures and temperatures. In the absence
of any boundaries, a cavitation bubble remains spherical during
collapse, releasing energy primarily by sound radiation, the majority of
which is in the form of a shockwave

92. • Circumferential compression ( 壓縮 )
– The shockwave inside the stone advances faster through the
stone than the shockwave propagating in the fluid outside of the
stone. The shockwave that propagates in the fluid outside of the
stone thus produces a circumferential force on the stone
• Tear & Shearing ( 撕破 )
– In contrast to compression waves, which move the molecules in
the direction of propagation, a shear wave results in translation
of molecules transverse to the direction of propagation, and
therefore the molecules are not compressed but are shifted
sideways by the wave
• Dynamic squeezing: ( 擠壓 )
– Stone fragment by shear waves created inside the stone driven by
squeezing wave from the lateral stone borders
– A model accounts for all acoustic phenomenon

96. What are the imaging systems
during ESWL?
• Fluorosocopy
– Advantages
• In-situ tx of ureteric stones
• in all parts of ureter
• Shorter learning curve
– Disadvantages
• No direct targeting of radiolucent stones
• Small stones sometimes are difficult to locate
• Exposure to radiation
• USG
– Advantages
• Easy targeting of radiolucent stones and smaller renal stones
• Real-time imaging without excessive radiation exposure
– Disadvantages
• Is-situ treatment of ureteric stones is possibly only for prox and
distal ureter
• Longer learning curve

97. Factor influence efficacy
• 1. Focal zone:
– Diameter at which the peak pressure is half of
P+, known as -6dB
– Energy focused on stone depends on source
and method of focusing
– But focal zone has little relevance in the
disintegrative efficacy
– Usually: larger FZ  renal stone, small FZ 
ureteric stone
– In short : larger FZ  increase efficiency

98. • 2. Pulse rate frequency:
– Cavitation bubbles produced by the
rarefaction phase of the SW can decrease the
energy of the following impulse thru scattering
and absorption
– Longer pulse frequency  less bubble in the
path to decrease the energy
– Only the –ve phase is affected
– Increase PRF from 1Hz to 1.8Hz has drastic
effect on SW energy

99. • 3. Coupling
– HM3 use water bath  now coupling
cushions
– More air pockets  less SW efficacy
– Gel: use bubble-free USG gel
– Lower viscosity gel better
– Greater quantity of gel
– Apply gel from stock container as a large
amount rather than hand or zigzag application
from squeezed bottles

100. • 4. Localization & monitoring:
– Compression belt to reduce resp movement
– Larger FZ to reduce impulse miss the stone
– Real time coaxial USG localization
– Automated fluoroscopic localization
• 5. Impact on pulse rate:
– Reduce pulse from 2Hz to 1Hz increase stone
passage rate from 20%  80%
– RCT: 1Hz has better outcome vs 2Hz esp with stone
> 10mm (60% vs30%),

101. • 6. Ramping:
– Slow increase of generator voltage
– Less pain
– Pretreatment at lower voltage  reduce renal trauma
by vasoconstriction
• 7. SW energy:
– Stone fragmentation is achieved as long as the
threshold is exceed
– Base of effective energy dose (Eeff at intensity level x
impulses)
– Renal stone: Edose (12mm)= 100-130
– Ureteral stone: Edose (12mm) = 150-200

103. Contraindications
Absolute
1. Pregnancy
2. Uncorrected bleeding disorder
3. Uncorrected hypertension
4. Untreated infection
5. Body habitus (obesity or severe skeletal
malformations)
Relative
1. Aneurysm
2. Pacemaker
3. Downstream obstruction (e.g PUJ stone)
4. Excessive stone burden

104. What is the important point for
Steinstrasse?
• Internal ureteral stents are now commonly
inserted before ESWL for large renal stones, the
frequency of Steinstrasse has decreased
• Steinstrasse: Accumulation of gravel that does
not pass within a reasonable period of time , and
interferes with the passage of urine
• PCN results in passage of fragments
• URS: help remove the leading stone in distal
ureter

105. Factors predicting usefulness
• Stone free rate (EAU 2010)
– <1cm – 80%
– 1-2 cm – 60%
– >2cm – 50%
• Stone factors
– Size
– Site
– Composition as measure by HU on CT scan (> 1000)
– Calyceal anatomy
• Patient factors
– Age: for renal stone, age stone free rate
– BMI
– Stone skin distance
– Pain control

106. size
• EAU 2010
– >20mm consider PCNL although ESWL still an option
– > 40 x 30mm combine PCNL and ESWL 71%-96%
success (sandwich procedure)
• But single kidney can still try ESWL
• ESWL after PCNL better then vice versa
106
< 20mm > 20mm
Dornier HM3 75-89% 39-63 %
Newer model 45-60% 45-60%

108. Stone Burden
• Can be expressed in different way
– Largest diameter: length of stone on KUB
– Stone surface area (SA): Length, width
– Stone volume (SV): CT

109. Composition
• Stone resistant to ESWL in descending order :
– Cystine
– Bushite
– Ca oxalate monohydrate
– Hydroxyapatite
– Struvite
– Ca oxalate dihydrate
– Uric acid
• Matrix stone, soft stone composed of up to 65%
organic matter, compared to 3 – 4 % of most
noninfected stones, is associated with poor
outcome with ESWL, and PCNL is preferred

110. Hard stone
• Hard stone like cystine and brushite should be
treated with ESWL only when they are < 15 mm
in size.
• RIRS may be beneficial in cystine stone,
because life-time risk of recurrence, therefore
less renal trauma and less morbidity.
• EAU 2010 : cystine stone
– < 15mm ESWL 71% SFR
– > 20mm ESWL 40% SFR

111. What is the importance of shape & CT HU unit
to determining successful rate of ESWL to
cystine stone?
• Rough-appearing external surface on plain film
imaging were more apt to be fragmented with
shock-wave energy than those with a smooth
contour
• Computed tomography attenuation coefficients
of the latter were significantly higher in smooth-
type stones
• HU > 1000 asso with reduce stone disintegration
50% vs 100% if HU < 500 [Joseph JU2002]
• Stones with higher attenuation values have also
been demonstrated to be resistant to shock-
wave fragmentation

112. When is stenting required in
ESWL?
• Indication:
– Obstructed infected system
– New-onset of renal failure
– Stone > 2cm : steinestrasse after ESWL 10%
(vs 1% if < 2cm)
• Improve passage of stone
• Prevent obstruction
• Prevent loss of ureteral contraction

113. Stent with ESWL useful?
• Stent + ESWL for proximal ureteral stone
 does not affect stone fragmentation or
clearance, but associated with more
symptom (Grade 1B)
• Recommendation against stenting for
proximal ureteric stone
• Routine Ureteric stents compromise stone
clearance after shockwave lithotripsy for
ureteric stone [Tolly BJUI 2008]

114. Prophylactic antibiotic
• Antibiotic prophylaxis in pt with sterile urine before
txn reduce risk of UTI (2% vs 6% in placebo)
[MA ,Pearle Ju1997]
• Expert panel from AUA [JU2003]
– Not indicated for most of the urology patients
– Not indicated for pin, plate or screw
• Advised for patient who had increased risk of
hematogenous joint infection (Total joint
replacement)
– For total joint replacement within 2 years
– Immunocomprimised patient
– Co-morbidity
• Previous joint infection
• Malnourished
• HIV infection, DM, malignancy

115. Pain
• Related to energy density of SW as it passes through
skin, size of focal point
• short acting parenteral sedative narcotics: alfentanil,
midazolam, propofol
• topical agents: EMLA cream (mixture of lidocaine and
prilocaine) ， 45 mins before SWL
• Pain control is important to reduce patient movement
causing mistargeting
• Prefer: Oral + IV PRN (Alfentanil) [Ng 2009]
• those who receive GA experienced a significantly greater
stone free rate than IV sedation
• ( Due to more controlled respiratory excursion)

118. Evidence of pre-treatment SW
• Willis (2006) reported a practical way to protect the treated
kidney from clinical dose of shockwaves.
• Before the administration of a clinical dose of 2000 shocks at
24 kV with an unmodified HM3 lithotripter
• A pretreatment dose of 100 to 500 shockwaves at 12 kV is
administered, followed by the full clinical dose to the same site.
• Under these conditions, the normal lesion of approximately 6%
is reduced to approximately 0.3%, a highly significant change
• One hypothesis of a possible mechanism of this outcome
– Pre-dose of shockwaves induces vasoconstrictive event that prevents
an incoming stress from shearing the vessel wall
– Or prevents or reduces the number of cavitation events.
• A reduction in cavitation potentially protects the parenchyma from
cavitation-induced injury. A clinical trial is needed to test this result
in patients
• Occur when the treatment is apply to same or opposite pole (give
100 shock for pretreatment)

119. ESWL best practice (EAU)
• Best Txn of patient who desire txn with minimal anaesthesia
• Renal stone <2cm, ESWL first choice
• Lower SFR & more number of session need if stone> 1cm
• Ureteral stent should be inserted in case renal stone >2cm
• However , stenting should not be use for proximal ureteric stone 
dose not affect stone fragmentation or clearance but asso with more
symptoms
• Stones with medium density >1000HU upon NCCT are less likely to
be disintegrated
• Obesity – poor localisation with imaging and increase skin to stone
distance  poor outcome
• Women of childbearing age: caution in txn of distal ureteric stone
with ESWL  possibility of damage to undertilised egg or ovaries
• NO asso of SWL with HT and DM

120. • Mid-ureteric stone – prone
• Lower ureteric stone -Traditionally prone
• Optimal frequency is 1Hz (safer and more effective, start
with low energy and stepwise power ramping)
• Shock-wave frequency increases, tissue damage
increases
• Meta-analysis comparing 60 shocks/min vs 120
shocks/min
– Patient treated with 60 shocks/min, significant
greater likelihood of a successful treatment
• Escalating voltage may have protective effect against
ESWL damage and better stone clearance

121. • ESWL should be performed by urologist who was
experience in ESWL
• The number of ESWL sessions : not exceed three to five
• For more sessions, a percutaneous method
• No rules on how frequently ESWL sessions can be
repeated
• Two successive sessions must be longer for
electrohydraulic and electromagnetic lithotripsy than for
treatments using piezoelectric equipment
• Careful and long fluoroscopy and USG time is essential
• Decrease air pocket in coupling gel is essential – apply
USG gel to water cushion straight from container rather
than by hand
• Careful control of pain during treatment is necessary to
limit pain-induced movements and excessive respiratory
excursions

122. MET after SWL
• Meta-analysis BJUI 2009 Yefang Zhu : Tamsulosin
– Improves clearance of fragments after ESWL by 20%
– With ~1 week faster stone passage
– Reduce pain medication requirement
– Fewer returns to hospital
– Steinstrass resolve completely vs 25% require intervention in
placebo gp
– Work best esp in stone > 10 to 24mm
• K citrate for Ca Oxalate stone:
– Improve SFR
• MET vs ESWL:
– Equally effective in distal ureteric stone 4-7.9mm
– MET less effective in stone 8-9.9mm

123. Conclusion
• MET is recommended (both nifedipine and
tamsulosin) in facilitating clearance of
fragments after ESWL of ureteral stone
and to reduce pain medication
requirement

124. Complications after ESWL?Complications after ESWL?
1. Pain
2. Hematuria
3. UTI and occasional sepsis
4. Steinstrasse complicates (1-4%)  10% if > 2cm
5. Perirenal hematoma (25% radiological) (<1%
significant)
6. Renal edema
7. Gastric or duodenal erosion commonest extra renal
complication of ESWL
8. Arrhythmia during ESWL session
9. Chronic: Still some controversies
– HT
– DM
– Decrease RFT

125. Who are at risk of complication?
• Acute renal injury may be more likely to
occur in patients
1. Pre-existing hypertension
2. Prolonged coagulation time
3. Coexisting coronary heart disease
4. Diabetes
5. Solitary kidneys

127. URSL

128. Indications
• Stone factor:
1. ESWL failure
2. Lower pole stone
3. Cystine stones
4. Bilateral ureteric stone
5. Stone in a calyceal diverticulum
6. Stenosis of a calyceal infundibulum or tight angle between renal pelvis and
infundibulum. The flexible ureteroscope can negotiate acute angles and the
laser can be used to divide obstructions.
• Patient factors:
1. Obesity such that PCNL access is technically difficult or impossible
2. Obesity such that ESWL is technically difficult or impossible. BMI >28
3. Musculoskeletal deformities such that stone access by PCNL or ESWL
-e.g.kyphoscoliosis)
4. Bleeding diathesis
5. Horseshoe or pelvic kidney
• ESWL only 50% success
• PCNL difficult : bowel proximity and variable blood supply
6. Patient preference

129. Advantage of URSLAdvantage of URSL
• Access to virtually the entire collecting system is possible
• Holmium:YAG laser has a minimal effect on tissues at distances of 2–3 mm
from the laser tip and so collateral tissue damage is minimal
• More effective treatment option than ESWL, with a lower morbidity than
PCNL
• laser lithotripsy (reliable method for treating urinary calculi, regardless of
hardness)
• It can also allow access to areas of the kidney where ESWL is less efficient
or where PCNL cannot reach
• Safely used in pregnancy
• Treatment of bilateral ureteral stone simultaneously
• Small stones and fragments are best retrieved with a basket or a forceps
• most suited to stones <2 cm in diameter
• Renal stone: ESWL and PCNL are recommended primary txn options
• Flexible URS: txn alternative for lower pole stone up to 20mm

130. Standard technique

131. Ho: YAG laser lithotripsy
• Regardless of hardness
• Ureteral stones: 365-um laser fibre
• Intracaliceal stone: 200-um fibre
• Better SFR at 3 months than EHL (97% vs
87%)

132. What are the advantages ofWhat are the advantages of
access sheath?access sheath?
• Ureteral access shealth: 9-16F
• Operating time might be reduced for
higher stone burdens where multiple
ureter passages are necessary
• The maintenance of a low-pressure
irrigation system by continuous outflow
through the sheath
• follow-up series indicate a low rate of
ureteric strictures

133. What is the advancement of
baskets?
• Nitinol baskets preserve tip deflection of flexible
ureterorenoscopes
• Tipless design reduces the risk of mucosa injury
• Nitinol baskets are most suitable for use in
flexible URS
• Nitinol baskets are more vulnerable than a
stainless steel basket, and laser or EHL might
break the wires of the basket

134. SFR
• Overall SFR: 81-94%
• Appropriate for stone of any size in proximal
ureter: SFR 81%
• Proximal stone: Flexible URS (87%) vs
Semirigid URS (77%)
• < 2cm: >80%
• > 2cm: 50%
• Majority of pt stone free in single procedure,
10% require auxillary procedure
EAU GL 2010

135. RIRS result on Renal stone
• SFR for stone < 15mm : 50-80%
• Larger stone can also be treated
successfully
• NOT recommended as 1st line for renal
stone
• Flexible URS could become 1st
line for
lower pole stones < 15mm
• Simultaneous URS + PCNL: not routine

136. Stone extraction
• Intraureteral manipulations with stone
basket should always be performed under
direct URS vision
• Fluoroscopic imaging of the stone alone is
not sufficient
• Obvious risk of injury to ureter

137. Consent:
Intraoperative complication
• Bleeding (0.1%)
• Ureteral injury (0.5%)
• Ureteral avulsions (0.1%)
• Stone migration (4%)
Early complication:
• Fever or sepsis (1%)
• Hematuria (2%)
• Renal colic (2%)
• Transient VUR (4%)
Late complication:
• Ureteric stricture (0.5%)

138. Stenting
• No improved fragmentation with stenting
• Frequent LUTS related to stents
• Routine stenting after uncomplicated URS not necessary
• Complications: stent migration, UTI , breakage , encrustation
and obstruction
• Increase expense, FC for removal
• Strong recommendation against routine stenting after
uncomplicated URS (Grade 1B)
• Clear indications:
1. Ureteral injury or perforation
2. Larger residual stone burden
3. Stone fragments >2mm remain in ureter
4. Impacted stone with edematous ureter
5. Prolonged manipulation (esp upper 1/3)
6. Stricture
7. Solitary kidney
8. Renal insufficiency

139. PCNL

140. Indications
• For stone <20mm, ESWL has the advantage of
lower morbidity
1. Stones >3 cm in diameter
2. Failed ESWL and/or an attempt at flexible
URSL
3. Staghorn calculi
• ESWL and/or repeat PCNL being used for
residual stone fragments.
• For stones 2–3 cm in diameter, PCNL gives the
best chance of complete stone clearance with a
single procedure, but this is achieved at a
higher risk of morbidity.

141. Prophylatic antibiotic?
• Mariappan and associates (2005) have reported that
– the best predictor of post-PNL urosepsis is stone culture or
renal pelvic urine culture results, rather than bladder urine
culture results.
– The fragmentation of stones, despite sterile urine, may
release preformed bacterial endotoxins and viable bacteria
that place the patient at risk for septic complications
• Therefore, struvite stone pt or in whom infection is
suspected should receive
– minimum of 2 weeks of broad-spectrum antibiotics before
surgery to reduce the risk of sepsis.
– Parenteral antibiotics should be administered preoperatively in
any patient in whom urinary infection is suspected.

142. • Patients with radiological evidence of struvite
stone should be treated with oral antibiotic x 2
weeks even with sterile urine ( 35 % incidence
of bacteruria after PCNL )
• Prophylactic antibiotic should be given to all
cases ( reduce the incidence of post-op UTI from
12 % to 2 % , Tolly )
• Cephalosporin is the most suitable prophylactic
antibiotic given in case of sterile urine because
the most common secondarily infecting
organism is Sta. Epidermidis

143. Procedure
• Pre-procedural USG + fluoroscopy:
– Best access site and stone position
– Ensure no organ within the planned path
• PCNL is the removal of a kidney stone via a track developed between the
surface of the skin and the collecting system of the kidney
• General anesthesia is usual, though regional or even local anesthesia (with
sedation) can be used
• Inflation of the renal collecting system (pelvis and calyces) with fluid or air
instilled via a ureteric catheter inserted cystoscopically
• A posterior approach is most commonly used
– below the 12th rib (to avoid the pleura and far enough away from the rib to avoid
the intercostals, vessels, and nerve)
– through a posterior calyx, rather than into the renal pelvis, because this avoids
damage to posterior branches of the renal artery that are closely associated with
the renal pelvis.
• Percutaneous puncture of a renal calyx with a nephrostomy needle
• Once the nephrostomy needle is in the calyx, a guide wire is inserted into
the renal pelvis to act as a guide over which the track is dilated
• An access sheath is passed down the track and into the calyx
• Through this a nephroscope can be advanced into the kidney
• An ultrasonic lithotripsy probe is used to fragment the stone and remove the
debris.

144. Calyceal Anatomy
• LAMP – lateral ant, medial post
• Brodel configuration:
– posterior longer, more lateral (many “l”)
– 69% Rt kidney is Brodel
• Hodson configuration :
– posterior shorter, more medial (“s”, no “l”)
– 79% Lt kidney is Hodson
• 99% superior calyceal group drain by 1 midline
infundibulum
• 96% midzone drained by paired calyces
arranged in 2 rows (anterior and posterior)

145. Puncture: Munver
Overall Cx Intrathoracic Cx
Infra - costal 5 %
Supra - costal 15 % ( 3 X )
Supra – 12th
10 % ( 2 X ) 1.5 %
Supra – 11th
35 % ( 7 X ) 23 %

146. Result
• For small stones, SFR 90–95%
• For staghorn stones, SFR of PCNL +
postoperative ESWL for residual stone
fragments : 80–85%

147. Result: upper pole puncture
• Tolley, Western General Hospital [BJUi 2007]
• 66 PCNL with upper pole puncture
• Overall SFR : 78%
• Thoracic complication: 3%
• Overall complication: 30%
• Conclusion:
– Upper pole puncture asso with minimal morbidity
– SFR depends on size of stone rather than puncture
site

148. What are some tricks of PCNL?
• The puncture site on the skin lies in the extension of the
long axis of the target calix
• The puncture avoids aiming at infundibulum
• This is the safest access point because it uses the
infundibulum as a conduit to the pelvis
• Puncture pass thru papilla (no major blood vessels)
• Staghorn stone: subcostal or supracostal upper pole
puncture
• CT-guided renal access may be an option if failed
fluoroscopic or US guided
• Renal tract dilatation is possible using the Amplatz
system, or balloon dilators (no difference in morbidity, less
operation time but more cost)
• Lower pole puncture at posterior calyx - Mid-pole stone
will be left

149. Percutaneous antegrade access
• Indications:
– Cases with large impacted upper ureteric
stone (>15mm)
– Combination with renal stone removal
– Ureteral stones after urinary diversion
– Failure of retrograde ureteral access to large,
impacted upper ureteral stones
• SFR: 85% and 100%
• Complication rate: low and acceptable

150. What is mini-perc?
• Smaller shaft calibres of 12-20 F
• Mini PCNLVS PCNL (prospective study by Li Ly)
– Operation time was longer
– Blood transfusion rates lower
– No significant differences in trauma response
• As treatment time increases with stone size, this method
is recommended only for stones with a diameter < 20
mm
• The value of mini-perc in adults has not been
determined, but mini-perc is the method of choice for
percutaneous stone removal in children

151. What are the pros and cons ofWhat are the pros and cons of
supine PCNL?supine PCNL?
• RCT showed no difference between supine and prone
PCNL except less operation time in supine

152. Films taken after an urologic operation
• What has happened? (2)
• What is the incidence? (1)
Q23

153. • Colonic injury during PCNL
• <1% of PCNL
• In uncomplicated cases, tubeless percutaneous
nephrolithotomy, with or without tract fulguration, application of
a sealant or double-J stenting, is a safe alternative (RCT showed less
local pain / shorter hospital stay)

154. Tubless PCNL
• Exclusion criteria included :
– operative time longer than 2 h,
– three or more percutaneous accesses,
– perforation of the collecting system,
– bleeding,
– significant residual stone burden.
– Obstructed ureter
• All patients had antegrade stents placed after PNL
• ( 6F stents for stone patients and 14/7F stents for endopyelotomy
patients. )
• Adv :
– shorter hospitalizations (1.25 days)
– lack of external drainage tubes.
• Disadv :
– wearing a urinary catheter for 24 h,
– a second procedure is necessary for stent removal.

155. What are indication and
contraindication of PCNL?
• Indication:
– Stone > 3cm or staghorn
stone
– Renal pelvis stone > 2cm
– Lower pole stone > 1cm
– Anatomical abnormaly :
horseshoe kidney,
calcyceal diverticular
stone , obesity,
kyphoscoliosis
– Failed ESWL or URSL
– Foreign body
• Contraindication:
• Absolute :
– Bleeding disorder
– Proegnancy
– Spesis
– Poor kidney fxn
(nephrectomy)
– Need of open procedure
• Relative:
– Horseshoe or ectopic
kidney (bowel injury)
– Co-morbidities
– Anterior calyceal
divedrticulum

156. What are the complication of
PCNL?
• Access:
– Bleeding (10%)
– Require embolization (1%)
– Require nephrectomy (rare)
– Perforation of adj organ (bowel <1%, pneumothroax 0-5%)
– Hydrothorax in supracostal puncture (15%)
– Access failure (5%)
• Related to stone removal:
– Infection (bacteriuria 70%, sepsis 1%)
– TUR syndrome (rare)
– Extravasation of irrigant (30%)
– Renal pelvis injury
– Residual stone (10%)
• Others:
– Pleural effusion (10%)
– Mortality (<1%)

157. • Major bleeding:
– Termination of operation
– Placement of nephrostomy tube
– Secondary intervention at later date
– Clamp nephrostomy tube to stop venous
bleed
• Persistent or late secondary bleeding
– Artery injury
– Angiographic super-selective embolisation
– Nephrectomy is rare

158. Open/Lap renal stone surgery

159. Indications
1. Complex stone burden (projection of stone into multiple
calyces, such that multiple PCNL tracks would be
required to gain access)
2. Failure of endoscopic treatment
3. Anatomic abnormality that precludes endoscopic
surgery (e.g., retrorenal colon)
4. Body habitus that precludes endoscopic surgery (e.g.,
gross obesity, kyphoscoliosis)
5. Patient request for a single procedure where multiple
PCNLs might be required for stone clearance
6. Nonfunctioning kidney (pain, recurrent urinary infection,
hematuria) esp with staghorn stone to reduce infective
complication

160. Options
• Small to medium-sized stones
– Pyelolithotomy
– Radial nephrolithotomy
• Staghorn calculi
– Anatrophic (avascular) nephrolithotomy -
– Extended pyelolithotomy with radial nephrotomies
(small incisions over individual stones)
– Excision of the kidney, bench surgery to remove the
stones, and autotransplantation

161. Complications
• Wound infection (infection stones)
• Flank hernia
• Wound pain
• Stone recurrence after open stone surgery
• Scar tissue that develops around the kidney will
make subsequent open stone surgery
technically more difficult.
• The superiority of open surgery over less
invasive therapy, in terms of stone-free rates, is
based on historical experience, but no
comparative studies are available yet

162. Lap ureterolithotomy
• Retroperitoneal or transperitoneal access
• When other non-invasive procedure failed
• For both renal and ureteric stone
• Esp for stone in ventral caliceal
diverticulum
• < 2% conversion rate

163. Medical dissolution therapy

164. Indication
Uric acid stone:
• Uric acid stones form in concentrated, acid urine  to
decrease acidity of urine
• Hydration (urine output 2–3 L/day)
• Urine alkalinization
– Aim urine pH 6.5–7
– sodium bicarbonate 650 mg TDS or
– potassium citrate 30–60 mEq/day
• Allopurinol:
– For those with uric acid secretion > 1200mg/day
– Inhibits conversion of hypoxanthine and xanthine to uric acid
– 300–600 mg/day
• Dietary manipulation (low purine diet)

165. Cystine stones
• Most cystinuric patients excrete about 1 g of cystine per day
• Cystine solubility in acid solutions is low (300 mg/L at pH 5, 400 mg/L at
pH 7)
• Treatment:
– Reduce cystine excretion (dietary restriction of the cystine precursor amino
acid methionine and also of sodium intake to <100 mg/day)
– Increase solubility of cystine by alkalinization of the urine to >pH 7.5,
maintenance of a high fluid intake
– Drugs that convert cystine to more soluble compound
– D-penicillamine, N-acetyl-D-penicillamine, & mercaptopropionylglycine
– Bind to cystin  the compounds so formed are more soluble
– D-penicillamine (allergic reactions, nephrotic syndrome, pancytopenia,
proteinuria, epidermolysis, thrombocytosis, hypogeusia)
• Cystine stone are very hard
• Flexible ureteroscopy (for small) and PCNL (for larger) cystine stones are
used where ESWL fragmentation has failed

166. Chemolytic dissolution
• Adjunct to ESWL, PCNL, URS, open Sx to
achieve more complete elimination of small
residual stone/fragments
• Staghorn stone: ESWL + dissolution as low
invasive option
• 2 nephrostomy catheters
– to irrigate renal collecting system
– Prevent chemolytic fluid draining into bladder
– Reduce risk of increased intrarenal pressure
• Large stone burden
– JJ stent to protect ureter

167. Percutaneous chemolysisPercutaneous chemolysis
• Infection stone
– 10% solution of Hemiacidrin (Renacidin), pH 3.5-
4, or
– Suby’s G solution
– Abx prophylaxis
– One PCN in, another PCN out
– Increase contact surface area with ESWL
– Several week chemolysis + ESWL x complete
staghorn
– Option of High risk pt
– Risk: cardiac arrest due to hypermagnesaemia
– Contraindicated in immediate postop stage

168. Percutaneous chemolysis
• Brushite stone:
– Hemiacidrin/ Suby’s G solution, for residual fragments after other
Tx
• Cystine stone
– Soluble in alkaline
– 0.3-0.6mol/L THAM (trihydroxymethyl aminomethan) solution
(pH 8.5-9), or
– 200mg/L N-acetylcysteine
• Uric acid stone
• THAM
• Dissolve with bicarbonate treatment
• Ca Oxalate or ammonium urate stone
– No useful Rx
– Ca Oxalate in infection stone markedly reduce stone solubility in
Hemiacidin

169. Treatment

170. Natural history of renal stone
• 15% pass & 50% require intevention in 5yr [Glowacki
1992]
• Asymptomatic calyceal stone < 15mm: no difference
SFR, QOL, RFT & admission [MRC, Keeley BJU2001]
• EAU 2010: Spontaneous stone passage rate
• Renal stone
– < 4mm : Spontaneous pass 80%
– 6-10mm : pass 10-53%
– Stones > 5 mm - highly likely obstruction, drop in relative renal
function and require intervention
• Ureteric stone
– Proximal 25%, mid 45%, distal 70%

171. WW ? For who
• Traditional indications for intervention are pain, infection, and obstruction
• Asymptomatic stones followed over a 3-year period are more likely to
require intervention (surgery or ESWL) or to increase in size or cause pain if
they are >4 mm in diameter and if they are located in a middle or lower pole
calyx
• Patient’s job

172. What are the indications forWhat are the indications for
active stone removal? EAUactive stone removal? EAU

173. Renal stone: recommendations
• Method offering lower invasiveness or
morbidity should be selected
• < 10mm  ESWL
• 10-20mm  ESWL as first line but PCNL
is 1st
line for LPS
• > 20mm  PCNL is preferred
• Uric acid stone: oral chemolysis +/-
disintegration

174. Staghorn stone

175. Staghorn stone
What is staghorn stone?
• Definition: Stone with a central body and at least one
caliceal branch
• Partial staghorn: fills only part of collecting system
• Complete staghorn: fills all calices and renal pelvis
What is it compose of ?
• Struvite stone (calcium, ammonium and magnsium
phosphate)
• Urea spliting organsim (PKS PPS)
• Urea  ammonia (NH3) + bicarbonate
• Ammonia(NH3) + H2O  ammonium NH4 + OH

176. Staghorn stone
Why need to treat staghorn stone?
• According to study by Blandy and Singh [JU1976]
– Staghorn stone cause symptom
– If left with observation : 28% die of stone related renal failure
– If treat with surgery: mortality is only 7%
• According to study by Teichman [JU1995]
– NO patient with complete stone clearance die of renal –related
disease vs 3% without clearance of fragments and 70% who
refuse surgery
• ~30% of patients with staghorn calculi who did not
undergo surgical removal died of renal-related causes—
renal failure and urosepsis
• Thus treatment of staghorn stone is indicate

177. How should staghorn stone be
treated?
For stone> 2cm
• ESWL: No because SFR 40-60% at most
• Flexible URS: no because SFR < 60%
• PCNL : yes because highest SFR : >90%
• Open surgery vs PCNL in complete staghorn stone
[Egypt Gp (Al-Kohlany, JU2005]
• Conclusion:
– PCNL approaching the SF of open
• At discharge (49% vs 66%) and at FU (74% vs 82%)
– PCNL : lower morbidity, shorter operative time, shorter hospital
stay and earlier return to work
– Stone-free rates for both groups at follow-up were
approximately 80%

178. AUA GL – stone free rate
SFR Significant
complication
Transfusion Procedure
per patient
PCNL 78% 15% 18% 1.9
PCNL + SWL 66% 14% 17% 3.3
SWL 54% 19% Very low 3.6
Open surgery 71% 13% ~20-25% 1.4
MEDLINE search 1992 – 7/2003
Combine SFR lower because the last procedure is SWL in some series

179. Bilateral staghorn stone
• Manage symptomatic first, then good
function side in bilateral staghorn disease
– Determined by DMSA, best for the differential
function
– Simultaneous bilateral PCNL is safe with
advantage of single anesthesia except large
stone burden and complex pelvicalyceal
system

181. Lower pole stone

182. Natural hx of LPS
• From 4 reports
o Approximate 10-20% asymptomatic
stones become symptomatic per
year
o For these, 50-60% eventually require
surgical intervention
Lotan et al J Urol 2004 172 (6) p2275-81

183. Any benefit of treating it?
• MRC trail [F.X Keeley el at. BJUi 2001, 87, 1-8]
• Preliminary results of a randomiszed controlled trial of
prophylactic SWL for small asymptomatic renal calyceal
stones
• 228 patients randomised to ESWL vs control
• All <15mm stone, > 70% LPS
• ESWL Max 3 session
• FU 2.2:
• SFR: ESWL 28% vs observe 17% (insignificant)
– addition tx ( include analgesic/ antibiotic / JJ / URS ):
ESWL 15% vs observe 21%
• Thus: ESWL will have an increase SFR & less additional
txn require

184. Is ESWL less effective in LPS?
• Overall SFR of LPS vs upper & mid PS
– 60% vs 90%
– Meta-analysis by Lingeman [JU1994]
• Stone size stratification
– Up to 10mm: 75%
– 11-20mm: 55%
– Over 20mm: 30%

185. What determine the SFR of
LPS?
• Lower pole collective system anatomy [Sampaio JU1992]
1. Angle btw lower LP infundibulum & renal pelvis
2. Diameter of the LP infundibulum
3. Spatial distribution of the calyces
– But they are controversial
• How do they affect?
– Lower pole infundibulopelvic (LIP) angle as define as:
– Angle btw lower border of the pelvis with medial border of the LP
infundibulum [Keely EU1999]
– Angle btw central pt of renal pelvis & central axis of LP infundibulum
[Elbahnasy JU1998]
– Elbahnasy found that favourable factors as (LIP>70, infundibular
length < 3cm & width > 5cm)  All 3  all clear vs 16% if none
– But other studies show conflicting result

186. Any way to improve SFR in ESWL
of LPS?
• Pace JU 2001
• Percussion , diuresis and inversion (PDI)
• SFR 40% (PDI) vs 3% (observation gp)

187. ESWL vs PCNL vs URSL
• PCNL vs ESWL : Lower Pole I [Albala JU2001]
– Prospective multicenter RCT , LPS < 3cm, SFR at 3m
– SFR: PCNL (95%) vs ESWL (37%)
– Complication: PCNL (23%) vs ESWL (12%) [insignificant]
– Conclusion:
• ESWL = PCNL for treatment lower pole stone < 10 mm
• PCNL should be indicated for LPS > 10 mm
• URSL vs ESWL: Lower Pole II [Pearle JU2005]
– LPS < 1cm, SFR at 3m
– SFR: 50% (URS) vs 35% (ESWL)
– SFR: URSL 15% better than ESWL (not significant)
– Conclusion:
• ESWL = URSL for LPS < 1cm
• ESWL has shorter txn time & recovery, better acceptance
• Thus URSL can be offered if ESWL failed as Lower morbidity than
PCNL

188. Counseling
• LPS < 1cm:
– Offer ESWL as less invasive
• LPS 1-2cm:
– PCNL, RIRS, ESWL are all acceptable options
– URSL or PCNL : less depend on lower pole
anatomy
• LPS > 2cm:
– PCNL : outcome independent on stone size
and renal anatomy

189. Lower pole stone

190. Calcyceal diverticulum stone

191. What is calyceal diverticulum?
• Congenital in origin
• Non-secretory urothelial-lined
compartments that communicate with
collecting system
• Pt of communication often very narrow
• 25% associated with stone, which will not
pass
• Other than treating stone  obliteration of
diverticulum during PCNL is needed

192. What is the SFR?
• ESWL 30%
• URSL + incision 70%
• PCNL + obliterateion 90%
If ESWL failed to clear fragment , why?
• Calyceal diverticulum
• Stone is too hard (ca oxalate
monohydrate)

193. Horseshoe kidney stone

194. Horseshoe kidney
• Prevalence: 1 in 400
• Pathology: abnormal medial fusion of the
metanephric blastema  failure of ascent and
rotation of kidney (by IMA)
• Anatomical difference:
1. Kidney in more caudal position
2. Renal pelvis is anterior to all calyces
3. Ureter insert high and lateral on renal pelvis
4. Calyces point posteriorly , lower pole calyces point
caudal and medially

195. Management
• ESWL:
– Reasonable 1st
line treatment
– Problem:
• Difficulties in stone location (medial rotation , bowel gas, bone )
• Impairment of drainage (dilated collecting system, urinary stasis & high
insertion of ureter)
• URSL:
– For small sympotomatic stone not responding to ESWL
– Flexible instrument for tortuous ureter & complicated intra-renal
anatomy
– Reasonable SFR
• PCNL:
– For stone >2cm , failed ESWL & URSL
– Puncture: Upper pole posterior calyx
– Tract is more medial (increase risk of bowel injury , less pulmonary
injury)
– Use flexible instrument to reach lower pole
– SFR: 70%

196. Ureteric stone

197. Presentation
• Sudden onset of severe Flank pain that is
colicky (waves of increasing severity are
followed by a reduction in severity, but it
seldom goes away completely)
• It may radiate to the groin as the stone
passes into the lower ureter
• Patient moves around, trying to find a
comfortable position

198. Investigation
• Bld
• MSU
• Dip stick hematuria
– sensitivity for detecting ureteric colic
• ~95% on the first day of pain,
• 85% on the second day
• 65% on the third and fourth days
• pregnancy test in premenopausal women

199. NCCT
1. Greater specificity (95%) & sensitivity (97%) for
dx of ureteric stone
2. Can identify other non-stone cause of loin pain
3. No contrast injection need (RFT)
4. Faster (min)
5. Cost equivalent to IVU in high volume center
IVU:
• Less radiation exposure
• Show level and degree of obstruction

200. NCCT
• Can also predict fragility of stone under ESWL:
• We observed that for calcium stones, the number
of SWs to comminution was generally less than
half the stone CT attenuation value in Hounsfield
units (in those w/ 3-mm scans).
• This "half-attenuation rule" predicted the number
of SWs needed to complete fragmentation for 95%
of calcium stones (24/24 calcium oxalate
monohydrate, 13/13 hydroxyapatite, 8/10 brushite
stones).
• Saw K C et al Calcium stone fragility is predicted by helical CT attenuation values. J. of
Endourology 2000 Aug;14(6):471-4

201. Mx of acute renal colic
• Pain control: NSAID
• MOA: by smooth muscle relaxation and reducing
ureteral peristalsis
• Caution: Can affect RFT in patient with an
already reduced function
• Ev:
– Cochrane review 2005
– Opioid vs NSAID
– NSAID: lower pain score, less likely to require rescure
medication
– Opioid: more adverse effect (Nausea)
• If suboptimal pain control
• Add opioid analgesics e.g. dologesic/ pethidine

202. Prevent recurrent colic
• Double-blind, placebo-controlled trial
• Diclofenac 50mg TDS x 7 days after discharge vs
Plecobo
• Result:
– significant fewer colic (p < 0.01)
– difference was greatest during the first 4 treatment days
• Conclusion: oral treatment with diclofenac was effective
as short-term prophylaxis of new colic episodes,
especially during the first 4 days, and reduces the
number of hospital readmissions significantly. The stone
passage rate appears not to be affected

203. Mx: Renal colic
• Medication: Pain relief
– Voltaren SR 100mg QD PO PRN (RFT)
– Pepcidine 20mg BD PO
– Pethedine 50mg Q6H IM PRN
• Medication: antibiotics ?

204. Do we need to over hydrate
patient?
• Reason: increase urine output to “Flush”
the stone out ?
• In fact, renal blood flow and UO fall in
episode of obstruction
• Excess fluid excretion will cause greater
hydronephrosis  further impair
peristalsis

205. Treatment options
• Tailored to individual patient:
• (past health, obesity, stable clinical
condition, responding to analgesics)
• 1. Observation and medical therapies
• 2. Ureteroscopy
• 3. ESWL
• *2007 Guideline for the management of ureteral
calculi. Gleen M. Preminger et al, Journal of
urology 2007 dec vol 178; 2418-34*

206. MET
• Chances of spontaneous passage of
stone
– <4mm : 90%
– <5mm : 70%
– 5-10mm: 50%
– Proximal 25%, mid 45%, distal 70%
– Average time for spontaneous stone passage
for stones 4–6 mm is 3 weeks
– Stones that have not passed in 2 months are
unlikely to do so
• Effects: Ureteral SM relaxation , Limits
pain, Accelerated SFR

207. MET
• For stone < 5mm : no additional benefit with MET
• For stone 5-10mm , MET with alfa blocker is suggested
when:
– No contraindication:
• Pain not controlled
• Septic
• Derange in RFT
• Hypotension
– Benefit: 29% more patient will pass their stone than control, less
colicky & analgesic requirement
– Risk: 5% drop out due to hypotension
• Ca channel blocker: only 9% more (not significant)
• CCB vs AARB: 20% improvement in SPR with alpha
blockers [MA Hollingsworth Lancet. 2006]
• Single use of corticosteroid is discourage

208. • Time for stone passage: 4-6 weeks
• Vast majority of trials were limited to
patients with distal ureteric stones
• Tamsulosin is most studied , but all alfa blockers
works well class effect (YILMAZ JU2005)
• MET using tamsulosin resulted in a $1132 cost
advantage over observation (Bensalah et al.
EJU 2008)
• MET in paed gp is not effective [Aydogdu
JU2009]

209. Mechanis of Action
• Ureter SM relaxation
• Alpha-1 adrenergic receptor
anatagonist in ureter in
humans and animals
• Density of alpha1-anatagonist
significantly higher than
alpha2/ beta
• Prevalence of alpha1a
(subtype) in human
Inhibit basal tone,
peristaltic frequency
and ureteral
contraction
Decrease basal and micturating bladder neck pressure
Decrease intraureteric pressure
Increase fluid transport ability
Facilitate spontaneous expulsion of ureteric stone

211. Definitive treatment
• For stone >10mm: No recommendation can be
made for spontaneous passage (with/without
therapy)
• Consideration factors:
– Stone size & location
– Renal function
– Presence of a normal contralateral kidney
– Tolerance of exacerbations of pain
– Job and social situation
– local facilities

212. Stone removal
• Based on the: 2007 Guideline for the Management of
Ureteral Calculi (joint EAU/AUA nephrolithiasis guideline
Panel)
• Both ESWL and URS should be discussed as initial
treatment options
• Stone free rate, anaes, additional procedures and
complications
• URS has better chance of stone free with single
procedure , but higher complication rates
• URS has greater stone-free rate for majority of stone
stratifications

214. Stone free rate
ESWL URSL
Distal ureter Overall 74%
 94%
< 10mm
 97%
> 10mm
 93%
Mid ureter Overall No difference (86%)
< 10mm
> 10mm
Proximal ureter Overall No difference (80%)
<10mm
 90% 80%
>10mm 70%  80%

215. Open and Lap
• In difficult situations
– Very large impacted stones
– Multipler ureteral stones
– Concurrent conditions requiring surgery
• Lap Ureterolithotomy:
– Alternative to open surgery
– Less successful in distal ureter then
mid/proximal
– Median stone-free rate: 88%

216. Conclusion
• The more distal the stone, more in favor of
URS
• SFR were consistently higher for smaller
stones
• URS SFR show less size dependence
• The data for middle ureteral calculi may
not be as reliable as the overall outcome
data (smaller sample size)
• A higher retreatment rate for SWL

217. What is cost effectiveness
between URSL VS ESWL?
• Observation was least costly if no extra cost was
incurred by failed observation
• Ureteroscopy was less costly than ESWL for
stones at all ureteral locations
• *all patients in URS groups were stented
• *URS as an out-patient procedure
• *Based on US health system
– Lotan et al. Management of ureteral calculi: cost comparison and
decision making analysis. Journal of Urology, 2002. Vol 167, 1621-29

218. When is drainage required?
1. Pain that fails to respond to adequate
analgesics or recurrent pain
2. Associate fever and sign of sepsis (vitals,
WBC)
3. Impaired RFT (obstructed solitary
kidney / bilateral ureteric stone)
4. Obstructed stone > 4-6 weeks
5. Personal occupation reasons (pilot,
control machine, driver, etc)

219. In obstruction : PCN or JJ?
PCN
Advantage:
•Rapid decompression
•No manipulation of ureter to
flare up sepsis
•Low failure rate
•Monitor UO from kidney
•Accessible tract for future use
Disadvantage:
•Require radiologist
•Injury to other organs
•Nephrostomy bag
JJ
Disadvantage:
•Takes time to perform
•Manipulation of ureter (sepsis
and injury)
•Failure rate (impact stone)
•Fail to monitor UO
•NO accessible tract
Advantage:
•Performed by urologist
•Able to dilate ureter for future txn
•NO risk of injury to other organ
•Internal drainage

220. Management of stone with PUJOManagement of stone with PUJO

221. What is the management of
stone with PUJO?
• Either percutaneous endopyelotomy or
open reconstructive surgery
• Transureteral endopyelotomy with
Ho:YAG laser endopyelotomy
• Incision with an Acucise balloon catheter

222. Treatment ofTreatment of
pediatrics stonespediatrics stones

223. Investigation:
• < 1% of stone in patient <18 years
• Doppler USG: Severity of obstruction
– The ureteric jet
– Resistive index of the arciform arteries
– US will fail to identify stones > 40%
• NCCT & IVU :
– detect 95% of stones (rarely need sedation)
– Provide anatomical and functional info
• MRU:
– Cannot be used to detect a urinary stone
– Provide detailed information of anatomy , the location of an obstruction or
stenosis in the ureter, and the morphology of renal parenchyma
• Urine:
– serum chemistry and 24-hour urine collections
• Identify underlying pathology:
– VUR
– PUJO
– Neurogenic bladder or other voiding difficulties

224. Txn: WW
• Spontaneous passage of a stone is more
likely to occur in children than in adults
• < 5 mm are likely to pass spontaneously in
up to 98% of paediatric patients
• Use of MET is not proven in paed age gp

225. Txn: ESWL vs URSL
• Indications for ESWL (same as adults) stones
with a diameter up to 20 mm are ideal cases
• GA need: 30-100% (age and type of lithotriptor)
• URS: primary / after failed ESWL
• Semirigid URS: 4.5 and 6.0 F
• Flexible URS: 5.3 F
• ESWL: less efficient (cystine, brushite, Ca
oxalate and anatomic abn)

226. What are stone-free results for
pediatric patients?
• The very small number of patients in most groups,
particularly for URS, makes comparisons among
treatments difficult
• SWL may be more effective in the pediatric subset than
in the overall population, particularly in the proximal and
mid ureter
• Stone-free rate:
– 67-93% (short term studies)
– 57-92% (long term FU studies)
• Retreatment rate: 14-54 %
• Need for ancillary procedures: 7-33 %
• Residual fragments should be closely FU

227. Ureteral stone
• Spontaneous passage: 98% of <5mm
• ESWL: txn choice for most stone, success
rate fall as stone passed to distal parts
• Overall SFR: 80-97%
• Success rate for proximal and distal stone:75
-100%
• URS is the treatment of choice in mid and
distal ureteric stone in children
• Flexible URS : for proximal ureteric stone/
lower pole stone <1.5cm

228. ESWL for ureteric stone
• Txn of choice for proximal ureteric stone
• Difficult case:
– >10mm , impacted stone
– Ca oxalate monohydate / Cystine
– Unfavourable anatomy
• Stent is rarely need
• Ureteral pre-stenting: decrease SFR after
initial txn (retreatment rate: 12-14%)

229. Paediatric
• ESWL may be more effective in mid & lower ureter

230. Stones in pregnancyStones in pregnancy

231. Physiological change
• Increase cardiac output
• Increase in vascular volume, renal output (+60%), GFR (+40-65%)
• 1cm kidney size increase
• Increased rate of filtered Cr/Ur/Na/Ca/urate
• Decrease Serum Cr level
• Hypercalciuria
– Increase intestinal Ca absorption
– Increase renal Ca filtration
– Increase in 1,25OH-D3 produced by placenta
• Same incidence of stone as increased inhibitors (e.g. citrate, Mg,
glycoprotein)
• More alkaline urine due to respiratory alkalosis
Incidence of ureteric stone:
• 1 in 2000
• Most in 2nd
or 3rd
trimester
• Significant risk of pre-term labour

232. Differential diagnosis of flank pain
• Physiological hydronephrosis
• Ureteric stone
• Placental abruption
• Appendicitis
• Pyelonephritis
• All other cause of flank in non-pregnant
women

233. Physiological changes
• Physiological dilation of upper tract
– Occurs between 6th
and 10th
weeks (7weeks)
– Disappears 4-6 weeks after delivery
– 90% right hydronephrosis at 3rd
trimester
– Right side predominant
• Progesterone with ureteral smooth muscle
relaxation
• Uterine dextrorotation
• Compression by ovarian and uterine vein
• Protection of left ureter by sigmoid

234. Ultrasound
• First line investigation: Sp 34%; Sn 86%
• Cannot differentiate physiological vs
pathological dilation
– Dilation up to pelvic brim: physiological
– Dilatation below pelvic brim : distal obstruction
• 1st
trimester: right <18mm; left <15mm
• 2nd
/3rd
trimester: right <27mm; left 18mm
• Look for absence of ureteral jet
• Resistivity index >0.7 or difference from the
other kidney > 0.06

235. Effect of radiation
1. Congenital malformation: reduced head circumference/ microcephaly,
hypoplasia of the genitalia, hypospadia, micropthalmia, cataract
2. IU growth retardation
3. Mental retardation
4. Miscarriage
5. Cancer risk (leukaemia)
6. Mutagenic effects (inherited disease in offspring)
• Fetus most at risk : 4-10 week (1st
trimester)
• Radiation dose > 150mGy  significant increase risk of malforation
• Radiation dose < 100mGy  unlikely to have adverse effect
• Radiation dose < 50mGy  negligible effect (National Council on Radiation
Protection)
• Majority of diagnostic procedure did not involve fetal exposure
>50mGy (5000mrad)
– 1 min fluoroscopy time (2mGy / 200mrad)
– X-ray = 1mGy/radiograph
• American College of Obstetritian and Gynecologists guideline
– Exposure to X-ray during pregnancy is not an indication for therapeutic abortion

236. • Thus for radiation dose > 150mGy:
• 100 KUB
• 88 IVP (6 shot)
• 12.5 CT abd , 4 CT pelvis
• 250 times JJ insertion

237. However, every healthy mother…
• 3% risk of birth defect
• 15% for miscarriage
• 4% prematurity
• 4% growth retardation
• 1% mental retardation / neurologic developmental
problems
(Brent RL, Mettler FA. Pregnancy policy. AJR 2004: 182: 819-822)
• Need to explain that the baby is not
guaranteed to absolutely healthy after x-
ray explosure

238. If USG not adequate ? What can be
done
• 3 shot IVU: plain, 30s, 20min
• Low – dose CT
• MRU

239. IVU
• Taken plain, 30s, 20min (3 shots IVU)
• Use high sensitivity film, reduce aperture,
digital radiology, lead apron for the side of
health kidney
• Radiation exposure
• Overlap with fetus
• Suboptimal film quality

240. NCCT
• High dose of irradiation
• Avoid in pregnancy
• Low dose CT with average radiation
~700mrad (7mGy) (Wesley, J of
endourology 2007)

241. MRU
• T2 weighted image
• Sensitivity and specificity (100% for decting ureteric
stone)
• Patient needs to stay still in the machine in a period
of time in frank pain
• Stone as filling defect
• Not advised in the course of 1st
trimester (Louca
1999)
• High resolution MRI available

242. Messsage
• Avoid all radiation at 1st
trimester
• Use US as first line imaging modality
• Although estimated risk of diagnostic
radiation during pregnancy is low,
particularly 2nd
and 3rd
trimester, need to
balance the risk of radiation and risk of
untreated obstruction

243. Management of renal colic
• Imaging to confirm the diagnosis
• 1st
Line : Hydration + analgesia +/- antibiotics
• If physiological: usually not require stenting /PCN
• Analgesia
– Paracetamol can be used with no risk
– Codeine contraindicated at 1st
trimester; can be used episodically
during 2nd
/3rd
trimester
– Morphine with short duration to avoid maternofetal dependence,
growth delay, prematurely induced labour; avoid at the beginning
or or during labor
– NSAID : avoid for premature closure of ductus arteriosus,
pulmonary HT, delay or prolong labour, bleeding during delivery
• Alpha-blocker & CCB : unknown risk in pregnancy

244. Definitive
• 65% pass their stone during pregnancy
• 50% of the remaining pass after delivery
• Relief obstruction:
– JJ or PCN
– under LA + USG or GA + limited fluroscopy
– Problem: worsen irritative LUTS & repaid encrustation
– JJ need to be change 4-8 weeks
• Indication of treatment
– intractable pain, nausea, vomiting, febrile urinary tract infections,
obstructive uropathy, acute renal failure, sepsis, and obstruction
of a solitary kidney
• Treatment of stone:
– ESWL : cotraindicated
– PCNL: not advice for pt positioning & fluroscopy
– URSL: safe and effective in all trimester , SFR 70-100%

245. Antibiotics
Safe:
• Penicillin: OK
• Cephalosporin: OK
• Marcolide - Erythromycin (bacteriostatic): OK
Use with cautions:
• Nitrofurantoin: avoid in third trimester
– Fetal hemolytic anemia in G6PD deficiency mother
– hepatotoxicity, lung toxicity, inadequate urine concentration if GFR<60
• Aminoglycoside (bacteriostatic): CI in 2nd
and 3rd
trimesters
– can cross placental barrier: fetal ototoxicity & nephrotoxicity
– Used only for short periods for severe acute pyelonephritis threatening
materal-fetal prognosis
• Sulphonamide : contraindicated in third trimester
– Risk of neual tube defect in 1st
trimester due to anti-folate mechanism
– Risk of fetal anemia in G6PD def mother
• Triamethoprim : contraindicated in first trimester
– Neonatal jaundice

246. Contraindicated:
• Fluoroquinolone (bacteriostatic):
contraindicated as toxicity to fetal cartilage and
joints, tendon damage
• Chloramphenicol: contraindicated in third
trimester as “grey-baby” syndrome
• Tetracycline (bacteriostatic): contraindicated
as hepatotoxicity, deposit in teeth and bone
• Thiazide: fetal thrombocytopenia(not to be used)
• Allopurinol / D-penicillamine: fetal malformation
• Pyridium: OK

247. Ureteral stents
• Under LA / US guidance
• Allows return to normal activties
• Can be difficult to be placed (trigone
deformed by uterus, hyperemic mucosa)
• Bladder irritation, risk of displacement due to
dilation of upper tract, VUR causing back
pain and pyelonephritis
• Avoid incrustation by changing every 4-
8weeks, increase fluid intake, control Ca
intake, treat UTI

248. PCN
• LA, US guidance
• Risk of PCN
• Risk of encrustation; change 4-8 weeks
• Esp for very septic patients

249. URSL
• Risk of procedure: radiation/ureteric injury/
vascular injury
• Reduce discomfort from obstruction
• Under locoregional anaesthesia
• Ureters dilated already
• Use laser rather than EHL ( may induce labour) or
ultasonic lithotriptor (hearing damage)
• ESWL: contraindicated by fetal damage/radiation
• PCNL: contraindicated by difficult position,
prolonged anaesthesia/high radiation / induce
labour

250. Residual stones andResidual stones and
fragmentsfragments

251. CIRF
• Clinically insignificant residual fragments
• Most commonly seen after ESWL
• Most common site: Lower calyx
• NCCT show small fragments > KUB
• EAU 2010:
– <=4mm called residue fragment
– >=5mm called residue stone
• Infection stone:
• 2.2yr, 78% of stone fragment have progression
• Calcium stone: 6yr FU
– Stone growth: 26%
– Recurrent stone formation: 15%
251

252. Recommendations

253. General recommendations on
stone treatment
• Infections
• Anticoagulation and stone treatment
• Pacemaker
• Hard Stones
• Radiolucent stones

254. Infections
• Urine test should always be carried out
• Dipstick sufficient in uncomplicated case
• If infection and obstruction , drainage for
several days before staring active
intervention

255. Anticoagulation
• ESWL , PCNL and open surgery
contraindicated
• URS can be done with less morbidity
• Reduced risk of throboembolic
complications

256. Pacemaker
• Can be treated with ESWL provided that
cardiologist is consulted before
• Implanted cardioverter defibrillators need
to be de-activated during ESWL

257. Hard stones
• Brushite or Ca oxalate monohydrate
• PCNL for ESWL resistent cases
• Chemolytic treatment for brushite stone

258. Special problems

259. RecurrenceRecurrence
preventive treatmentpreventive treatment

260. How can stone be prevent?
• High fluid intake:
– 24-hour urine volume should exceed 2000ml
– Protective by reducing urinary saturation of Ca
,oxalate & urate
– Prolong time to stone recurrence (from 2 to 3 years)
– Reduce risk of stone recurrence (12% vs 27%)
– One large study found a risk reduction of 29% in
patients with a higher fluid intake
Curhan et al New Engl J Med 1993; 328: 833–8
• Juice:
– Grapefruit juice  increase risk (high oxalate)
– Orange juice  beneficial
– Cranberry juice  no effect

261. Dietary calcium & ca
supplement?
• Low dietary Ca intake is asso with higher risk of kidney stone
[Borghi’s RCT (NEJM 2002) and Curham’s large scale
epidemiological studies (NEJM 1993)]
• ↓ Ca intake => ↑absorption of oxalate in GI tract (due to decreased
binding with Calcium) => ↑urine oxalate excretion => Ca oxalate
saturation of urine increases rapidly with small increase in oxalate
• Normal Ca diet for most people (1000 mg/day)
• Moderate Ca restriction for absorptive hypercalciuria
• Ca supplement:
– Small risk of inducing kidney stone with Ca supplement vs no Ca
supplement
– Not recommended except in cases of enteric hyperoxaluria
– For those who need supplement , consuming supplement with meal or
with oxalate-containing food would reduce risk

262. Dietary factors
• Other dietary modification to reduce stone
formation
– Low sodium : should not exceed 5 g/day
– Low animal protein (0.8-1 g/kg/day)
– Vitamin C not > 500mg to 1g /day (precursor of
oxalate)
– Small quantities of wine
– Vegatatarian diet : alkaline content
– High fructose induce hypercalciuria, hyperoxaluria
and hyperuricosuria
– Reduce soft drinks
– Urate <500mg/day

263. Dietary factors
• Food rich in oxalate:
– Wheat bran, Rhubarb, spinach
– Cocoa, Tea leaves, Nuts
• Food rich in urate:
– Calf thymus
– Liver, kidney
– Poultry skin
– Herring with skin , sardines, anchovies, sprats
• Excess animal protein result in:
– Hypocitraturia
– Low pH
– Hyperoxaluria
– Hyperuricosuria
• High Na intake result in:
– ↑ Ca excretion (reduce tubluar reabsorption)
– ↓ urinary citrate (Loss of bicarbonate)
– ↓ effect of thiazide on ↓ urinary ca
• Combine Na and animal protein restriction  ↓ rate of Ca stone formation

264. Medication
• Pharmacological treatment should be instituted only
when the conservative regimen has failed
• The choice of drug therapy should be based on the
stone analysis and on the appropriate biochemical
investigations
• There are only three drugs with sufficient evidence on
stone prevention:
– thiazides in hypercalciuria
– allopurinol in hyperuricosuria
– postassium citrate in hypocitraturia
• Metaanalysis of RCT – medical therapy reduces 20% of
CaOx stone recurrence
– (Pearle, Pak J Endourol 1999)

265. Ca stones

267. What is suggested treatment for patients with
specific abnormalities in urine composition?

268. What is the medical treatment for urate
stone?

269. Thiazide
• Hydrochlorothiazide (25-50mg QD/BD),
bendroflumethiazide, trichlorothiazide, Indapamide
• Mechanism
– Increase Ca reabsorption in proximal and distal parts
of nephron
– ↓ oxalate excretion (↓ intestinal ca absorption)
• SE:
– Hypokalaemia, hypocitraturia and hyperuricosuria
• Loss of K should be replaced by K citrate 3.5-
7mmol BD (K citrate >>> KCl )
• EAU Indications: hypercalciuria

270. Alkaline citrate
• Potassium citrate (EAU), Na K citrate, Na citrate, K Mg citrate,
KHCO3, NaHCO3
• Mechanism of action.
– Alkalinizing salt increase urinary pH  increases the excretion of citrate

– reduce the supersaturation with calcium oxalate and calcium phosphate
– increase the inhibition of growth and aggregation (agglomeration) of the
corresponding crystal phases
• SE: GI upset, hyperkalaemia (!CRF)
• Compliance: ~50%
• Indications: hypocitraturia
• Ev:
– 2 RCT: K citrate significant reduced recurrence rate vs Na citrate

271. Orthophosphate
• Very weak evidence, NOT 1st
line choice
• Insufficient evidence to recommend its use
• Mechanism of action.
– reduce the synthesis of 1,25(OH)2-D vitamin.
• decreased absorption of calcium
• reduced calcium excretion;
• reduced resorption of bone
• increased phosphate excretion,
• increases urinary citrate and pyrophosphate (inhibitor of Ca
oxalate and Ca PO4 crystal growth)
• SE: Diarrhoea, abdominal cramps, nausea and
vomiting
• The possible effect on parathyroid hormone needs
attention
• Compliance: good

272. Magnesium
• Not recommended as monotherapy
• Combination with thiazide might prove useful
• Mechanism of action
– formation of complexes between magnesium and oxalate,
thereby reducing the supersaturation with calcium oxalate.
– Inhibit the growth of calcium oxalate / phosphate crystals
– ↑ citrate excertion
• SE: Diarrhoea, CNS disorders, tiredness, sleepiness
and paresis
• Compliance 70-80%

273. Allopurinol
• Indication:
– hyperuricosuric Ca oxalate stone
– uric acid stone
• Mechanism of action
– Reduced salting-out effect
– Decreased risk of uric acid or urate crystals as promoters of
calcium oxalate precipitation
– Complex formation between colloidal urate and macromolecular
inhibitors, and/or
– Reduced excretion of oxalate
• SE: Steven Johnson Syndrome
• No effect in patient without hyperuricosuria
• Compliance?

274. Pyridoxine (Vit B6)
• Co-enzyme pyridoxal PO4 increase
transamination of glyoxylate  ?affect
endogenous production of oxalate
• Use together with orthophosphate to tx
primary hyperoxaluria Type I or idiopathic
hyperoxaluria
• No RCT to show efficacy, but recommended
for primary hyperoxaluria Type 1