2. Epidemiology
Most patients tend to present between 30-60 years of age.
Male : Female (3 : 1)
More common in Asians and whites than in Native Mediterranean
Americans, Africans, African Americans.
Geography (stones are more common in hot and dry areas).
Diet and Hereditary also appears to be factor.
3.
4. Etiology
1.
Diet – Vitamin A deficiency causes desquamation of epithelium
which acts as a nidus for stone formation.
2.
Climate – In hot climate, urinary solutes will increase with decrease
in colloids, which leads to chelation of solutes with calcium forming
a nidus for stone.
3.
Citrate level in urine (300-900 mg/24 hours) maintains the calcium
phosphate and carbonate in soluble state. So any decrease in
citrate level in urine causes stone formation.
4.
Infection – Urea splitting organisms (E.coli, Staphylococcus, Proteus)
5. 5.
Prolonged immobilization – causes decalcification of bones so
hypercalciuria leading to stone formation.
6.
Metabolic –
Hyperparathyroidism causes hypercalciuria
nephrocalcinosis
B/L
Hyperoxaluria – result of altered glycine metabolism.
Hyperuricosuria (Gout)
Renal tubular acidosis
7.
Stasis/Slow urine flow – due to obstruction to urine flow (e.g.
ureteral stricture).
6. Stages of stone formation
1.
Super saturation
2.
Nucleus formation
3.
Crystallization
4.
Aggregation
5.
Matrix formation
6.
Stone
8. Calcium Oxalate Stones
80% of kidney stones contain
calcium
General appearance:
1.
White, hard, radiopaque
2.
Calcium PO4: staghorn in renal
pelvis (large)
3.
Calcium oxalate: present in
ureter (small)
4.
Called Mulberry stone (brown)
with sharp projections.
9. Phosphate Stones
10-15%
Either be Calcium phosphate
(magnesium or ammonium)
Occurs in infection
Smooth and white color
In alkaline urine, it enlarges rapidly,
filling renal calyces and taking
their shape (STAGHORN
CALCULUS).
Radiopaque
10. Uric Acid Stones
8% of renal stones contain uric
acid
associated with hyperuricemia
(with or without gout)
General appearance:
1.
Small, friable, yellowish
2.
May form staghorn
3.
Radiolucent (plain x-rays
cannot detect)
11. Cystine Stones
Occur in Cystinuria (defective
resorption of cystine from renal
tubules)
Autosomal Recessive
Form in acidic urine (soluble in
alkaline urine)
Soft, yellow
Radiopaque (contains sulphur)
13. Struvite Stones
Compound of magnesium,
ammonium phosphate mixed with
carbonate.
associated with chronic UTI
Occurs in presence of ammonia
and urea splitting organisms in
urine (e.g. Proteus, Klebsiella)
Radiopaque
14. Staghorn Calculus
Stone occupying the renal pelvis
and calyces
Triple phosphate stone
White in color, soft, smooth occurs
in pre-existing infection.
Unilateral/Bilateral
15. Clinical History
Classical features of renal colic (or ureteric colic)
Sudden severe pain – caused by stones in the kidney, renal pelvis or ureter,
causing dilatation, stretching and spasm of the ureter.
Pain starts at the level of the costovertebral angle (but sometimes lower)
and moves to the groin, with tenderness of the loin or renal angle,
sometimes with hematuria.
If the stone is high and distends the renal capsule then pain will be in the
flank but as it moves down pain will move anteriorly and down towards the
groin.
A stone that is moving is often more painful than a stone that is static.
The pain radiates down to the testis, scrotum, labia or anterior thigh.
16. D/D on basis of site of pain
1.
Biliary colic.
2.
Pyelonephritis: very high temperature. Pain is unlikely to radiate to the groin.
3.
Acute pancreatitis.
4.
Acute appendicitis.
5.
Perforated peptic ulcer.
6.
Epididymo-orchitis or torsion of testis: very tender testis.
7.
Sinister causes of back pain: usually tender over vertebrae.
8.
Drug addiction: There are reports of people with fictitious stories of renal
colic, designed to obtain an injection of pethidine.
9.
Münchhausen's syndrome.
17. D/D of Radiopaque Shadow
Calcified lumbar or mesenteric LN
Gallstone (10% radiopaque)
Concretion in appendix
Phleboliths
Ossified tip of 12th ribs
Chip fracture of transverse process of vertebra
Calcified renal tuberculosis
Calcified suprarenal gland
Foreign body in alimentary canal
18.
Caliceal calculi that are non-obstructing are usually asymptomatic.
Patients with small caliceal calculi may still have gross or
microscopic hematuria and may have colic symptoms despite the
lack of imaging findings suggestive of obstruction.
19. Calculi causing Hydronephrosis
Hydronephrosis is dilatation of the renal pelvis and calyces.
It can be caused by obstruction of the ureters or bladder outlet. Hydronephrosis can also result from
reflux (retrograde leakage of urine from the bladder up the ureters to the renal pelvis.
21. Ureter
Ureter has 3 Constrictions:
1.
Pelvic-ureteric junction
2.
When it crosses external iliac vessel
3.
Vesico-ureteric junction
22. Ureteric Calculus
1.
Always of Renal Origin
2.
Commonly of elongated shape
3.
Can get impacted at 3 constrictions of
ureter
4.
Can cause:
Obstruction
Hydronephrosis
Infection
Ureteral Stricture
5.
C/F:
Colicky Pain (from loin to tip genitalia) along
genitofemoral nerve.
Hematuria, dysuria, frequency, strangury
Tenderness in iliac fossa
23.
24.
25. Bladder Calculus
1.
Primary vesical calculus:
•
occurs in sterile urine
•
Comes down from kidney through ureter and
gets enlarged in bladder (usually oxalate
stone).
•
Can irritate bladder mucosa causing
hematuria
2.
Secondary vesical calculus:
•
Occurs in presence of infection (commonest
bladder stone)
•
Usually phosphate stone, occurs in bladder
only
26. Etiology
Same as that of Renal Calculus
Others:
1.
Diverticula bladder: which lead to
stagnation of urine superadded
infection stone formation
2.
BPH
3.
Urethral Stricture
4.
Neurogenic Bladder
5.
Schistosomiasis
27.
Bladder stones generally form in the
bladder itself.
Causes:
1.
bladder outflow obstruction
(enlarged prostate)
2.
neurogenic bladder (loss of bladder
function due to spinal cord
injury/disease).
3.
Those with bladder wall
abnormalities (ureterocele,
diverticulum) or
4.
those with recurrent urinary
infections are also at higher risk of
forming bladder stones.
When seen on an abdominal/pelvic
X-ray they are often multiple and
rounded.
28. Bladder Stone
Note that this stone has a faint
longitudinal lucency which is the
nidus around which the stone
developed.
29. Jack Stone
Jackstone calculi resembles toy
jacks.
composed of calcium oxalate
dehydrate
dense central core and radiating
spicules.
light brown with dark patches and
are usually described to occur in
the urinary bladder and rarely in
the upper urinary tract.
31. Clinical Features
Frequency more during day than night, because during day, due to
ambulation stone comes in contact with trigone of the bladder and
irritates.
Pain – referred to tip of penis or labia.
Burning micturition and fever.
35. Nephrocalcinosis
Refers to renal parenchymal calcification.
The calcification may be dystrophic or
metastatic.
1.
With dystrophic calcification, there is
deposition of calcium in necrotic tissue.
This type of parenchymal calcification
occurs in tumors, abscesses, and
hematomas.
2.
Metastatic nephrocalcinosis occurs most
often with hypercalcemic states caused
by hyperparathyroidism, renal tubular
acidosis, and renal failure.
Metastatic nephrocalcinosis can be
further categorized by the location of
calcium deposition as cortical or
36. Causes of Nephrocalcinosis
Causes of cortical nephrocalcinosis include
1.
acute cortical necrosis
2.
chronic glomerulonephritis
3.
chronic hypercalcemic states
ethylene glycol poisoning, sickle cell disease, and
rejected renal transplants
Causes of medullary nephrocalcinosis include
1.
hyperparathyroidism (40%)
2.
renal tubular acidosis (20%)
3.
medullary sponge kidney
bone metastases, chronic pyelonephritis, cushing’s
syndrome,
hyperthyroidism, malignancy, renal papillary necrosis,
sarcoidosis, sickle cell disease, vitamin D excess, and
Wilson’s disease.
37. Phleboliths
Calcification within venous structures.
Common in the pelvis where they may
mimic ureteric calculi, and are also
encountered frequently in venous
malformations.
Round in shape (but not always)
of a similar size that would correspond
to the diameter of pelvic veins
1.
look like a ring of bone
2.
tend to occur laterally around the
urinary bladder
3.
appear as focal calcifications, often
with radiolucent centers
39. Adrenal Calcification
Adrenal (suprarenal) calcification
is an uncommon finding and is
usually incidental. Most often it is
considered a result of previous
haemorrhage or tuberculosis.
43.
Gallstones have a variable
position depending on the position
of the gallbladder and may be
mistaken for renal stones
Unlike renal stones they are often
rounded and cluster together
45. Vascular Calcification
Calcification of arteries seen on xrays is a sign of more generalised
atherosclerosis.
Occasionally vascular
calcification seen on an
abdominal X-ray reveals an
unexpected aneurysm
46.
Typical appearance of calcified
abdominal aorta
Note the outward bulging of the
anterior wall
47. Renal Tuberculosis
Genitourinary tract tuberculosis.
Lobar calcification in a large
destroyed right kidney in a patient
with renal tuberculosis. Note the
involvement of the right ureter
51. Scrotoliths/Scrotal Pearls
The calcified lesions at the bottom of the
image are scrotal calculi which are also
known as a fibrinoid loose bodies or
scrotal pearl.
Scrotoliths or scrotal pearls are benign
incidental extra testicular macrocalcifcations within the scrotum. They
frequently occupy the potential space of
the tunica vaginalis or sinus of the
epidydimis. They are usually of no clinical
significance.
Causes
micro trauma / repetitive trauma to
scrotal
region - e.g. mountain bikers
prior torsion appendix of testis
52. CT Scan Renal Stone
On CT almost all stones are opaque, but vary
considerably in density.
1.
calcium oxalate +/- calcium phosphate: 400600HU
2.
struvite (triple phosphate): usually opaque but
variable
3.
uric acid: 100 - 200HU
4.
cysteine: opaque
5.
HIV medication related stones (indinavir)
difficult to visualize
53.
Protocol
1.
Collimation 5-7 mm
2.
Pitch of 1.5-2
3.
Slice reconstruction of 3 mm
Advantages:
1.
Avoidance of an injection of contrast
medium
2.
Rapid results
3.
Sensitivity 94%, specificity 97%
4.
Alternate diagnosis in patients with acute
abdomen pain
57. Conservative Rx
Flush Therapy – for low ureteric stones (drinking 2-3 litres of
water/day)
IV Fluids
Inj. Frusemide 60-80 mg
Anti-spasmodic agents to relieve the pain.
58. Sx
Most of the Stones can be removed without open Sx by:
ESWL - Extracorporeal shock wave lithotripsy (ESWL). This uses highenergy shock waves which are focused on to the stones from a
machine outside the body to break up stones. You then pass out the
tiny broken fragments when you pass urine.
59.
PCNL - Percutaneous nephrolithotomy (PCNL) is used for stones not
suitable for ESWL. A nephroscope is passed through the skin and into
the kidney. The stone is broken up and the fragments of stone are
removed via the nephroscope. This procedure is usually done under
general anaesthetic.
60.
URS - In this procedure, a thin ureteroscope is passed up into the
ureter via the urethra and bladder. Once the stone is seen, a laser
(or basket) is used to break up the stone.
61. Sx
Pyelolithotomy
1.
For stones in extrarenal pelvis
2.
Posterior subcostal incision
3.
Renal pelvis is opened, stone is
removed.
4.
Drain is placed and wound is
closed.
Extended Pyelolithotomy
1.
Incision on hilum over renal sinus
2.
To remove stones from pelvis and
calyces
62.
Nephrolithotomy
Incision behind the most convex surface
(Brodel’s line) and stone is removed
Nephropyelolithotomy
incision both over the kidney and pelvis.
Often done for Staghorn Calculus.
