2. HEADS
• Introduction & epidemiology
• Life cycle of hydatid worm
• Pathogenesis
• Clinical features
• Diagnosis & imaging
• Treatment
3. introduction
• Hippocrates recognized human hydatid over 2,000
years ago. The Arab physician, Al Rhazes, made
reference to hydatid disease of the liver in AD 900
• Zoonosis- Cestodes(platihelmithies)
E. granulosus, E. multilocularis, Rarely E. oligarthus
and E. vogeli
• E. granulosus, produce unilocular cystic lesions,
prevalent in China, central Asia, the Middle East, the
Mediterranean region, eastern Africa, and parts of
South America
4. • E. multilocularis, which causes multilocular alveolar
lesions that are locally invasive, is found in Alpine,
sub-Arctic, or Arctic regions, including Canada, the
United States, and central and northern Europe
• E. vogeli causes polycystic hydatid disease and is
found only in Central and South America
• Both intermediate and definitive hosts
• Definitive hosts are canines (Dogs)
5. • intermediate hosts—sheep, cattle, goats, camels, and
horses for E. granulosus, Red Fox, Mice and other
rodents for E. multilocularis
• Human is accidental intermediate hosts (dead end)
• Hepatic hydatid commonly involves right lobe of liver
(66%)
• Most common segment- segment VII (27%)
• Both lobes 16% and only left lobe 17%
7. Pathogenesis
• Hematogenous dissemination occurs primarily to the
liver
• Other organs may also be infected, including lung
(20%), brain, and bone (20%).
• Following tissue lodgment, cestode proliferation
occurs in the form of a slowly enlarging cyst.
• In 80% of affected individuals, the only manifestation
of echinococcal disease is a solitary cyst in a single
organ.
8. Pathogenesis
• A primary cyst in the liver is composed of three
layers:
1. Adventitia (pseudocyst / pericyst) – consisting of
compressed liver parenchyma and fibrous tissue
induced by the expanding parasitic cyst
2. Laminated membrane (ectocyst) – is elastic white
covering, easily separable from the adventitia
3. Germinal epithelium (endocyst) – is a single layer
of cells lining the inner aspects of the cyst and is the
only living component, being responsible for the
formation of the other layers as well as the hydatid
fluid and brood capsules within the cyst
9. Pathogenesis
• In some primary cysts laminated membranes may
eventually disintegrate and the brood capsules are
freed and grow into daughter cysts.
• Sometimes the germinal Epithelium protrudes out
towards the external side of the cyst, to form
exogenous daughter cysts, which if left untreated
may cause recurrence.
• The Hydatid cysts are slow growing approx. 1 – 3 cm
/ year and remain inapparent for long time
10.
11. Clinical features
• Male = female (Avg age 45 yrs)
• Approx 70% located in the right liver and are solitary
• Cysts are largely asymptomatic until complications
occur
• Symptoms of hydatid disease may be caused by
compression, obstruction, or displacement of
adjacent organs or structures
• The most common presenting symptoms are
abdominal pain, dyspepsia and vomiting
• May present as obstructive Jaundice (intrahepatic
biliary obstuction)
• Specially in children- chronic pain abdomen, wt loss
wasting
12. Clinical signs
• Hepatomegaly (most common)
• Palpable RUQ mass(cystic)
• Mass with Hydatid thrill (elicited by three-finger test)
• Cachexia in children
• Camellotte sign: Following intrabiliary rupture –
partial collapse of the cyst wall.
13. Complication
• Jaundice – due to pressure over biliary tree
• Pressure on portal vein can lead to portal HTN
• Rupture into biliary tree – may mimic recurrent
cholelithiasis, biliary obstruction & cholangitis (commonest
60%)
• Rupture into the peritoneal cavity – may cause potentially
fatal anaphylactic reaction and disseminated
intraabdominal echinococcosis
• Rupture into bowel, pleural cavity can occur.
• Bacterial superinfection of a hydatid cyst can occur and
present like a pyogenic abscess
14. Complication
• Erosion into surrounding structures or organs may
result in hematogenous dissemination such as to
lung, spleen, brain, muscles, bone and rarely kidney
• Parasite may die and cyst eventually may get
calcified.
• Hepatic dysfunction
• Cyst rupture may also be precipitated by minor
blunt abdominal trauma
15. Investigation
• Routine labs – nonspecific
Liver involvement may be reflected in an
elevated bilirubin or alkaline phosphatase level
Leukocytosis may suggest infection of the cyst
(fever)
Eosinophilia is present in 25% of all persons who are
infected
Hypogammaglobinemia is present in 30%
16. Investigation
• Primary serological test (hydatid serology) – Detect
Antigens
ELISA
IHA test
- 80-95% sensitivity for liver hydatid.
- IHA test is the initial screening tests of choice In
cases of diagnostic uncertainty
- Useful in follow-up to detect recurrence
17. Investigation
• Secondary serological test – Detect antibody against
parasite specific antigen
- Immunodiffusion and immunoelectrophoresis
demonstrate antibodies to antigen (Arc 5) and
provide specific confirmation of reactivity
- Sensitivity and specificity both approximate 90%
Sbihi Y, Rmiqui A, Rodriguez-Cabezas MN, et al: Comparative sensitivity of six
serological tests and diagnostic value of ELISA using purified antigen in
hydatidosis. J Clin Lab Anal 15:14, 2001.
18. Investigation
• Plain X-ray abdomen/chest
valuable for pulmonary hydatid
not specific for liver hydatid
• Thin rim of calcification
suggestive of an echinococcal cyst.
19. Investigation
• Ultrasound Abdomen
currently the primary diagnostic technique and has
diagnostic accuracy of 90%
Solitary Cyst – anechoic univesicular cyst with well
defined borders and enhancement of back wall
echoes in a manner similar to simple or congenital
cysts. Features are suggesting a hydatid etiology
include dependent debris (hydatid sand) moving
freely with change in position; presence of wall
calcification or localized thickening in the wall
corresponding to early daughter cysts
20. Investigation
Separation of membranes (ultrasonic water lily
sign) due to collapse of germinal layer seen as an
undulating linear collection of echoes
Daughter cysts - probably the most characteristic
sign with cysts within a cyst, producing a cartwheel
or honeycomb cyst
Multiple cysts with normal intervening parenchyma
Complications may be evident such as echogenic
cyst in infection or signs of biliary obstruction usually
implying a biliary communication
22. Investigation
WHO classification 2001
Useful for assessing stage of a liver hydatid on
ultrasound and to decide on appropriate
management for it depending on the stage of cyst
CL
CE1
CE2
CE3
CE4
CE5
25. Investigation
CE2
- Cyst with multiple septations
giving it multivesicular
appearance or rossette
appearance or honey comb
appearance with unilocular
mother cyst
- This stage is the active
stage of the cyst
26. Investigation
CE3
– Unilocular cyst with
daughter cysts with
detached laminated
membranes
appearing as water
lily sign
– This is the
transitional stage of
the cyst
27. Investigation
CE4
mixed hypo and hyperechoic
contents with absent
daughter cysts, these
contents give an
appearance of ball of wool
sign indicating the
degenerative nature of the
cyst
29. Investigation
• CT scan
Has the highest sensitivity of imaging of the cyst
(98%).
It is the best mode to detect the number, size, and
location, of the cysts.
It may provide clue to presence of complications
such as infection, and intrabiliary rupture.
CT features include sharply marginated single or
multiple rounded cysts of fluid density (3 – 30
Hounsfield units) with a thin dense rim. It is
supported by floating membrane within the cysts on
CT scan.
30. CT scan
• Provide adequate anatomic information for planning
surgical therapy
• It also allows improved definition of anatomy and
relationship to biliary and vascular structures
34. Investigation – MRI/ MRCP
• MRI provides excellent structural detail of hydatid
cysts and is superior to CT in demonstrating
alteration of the hepatic venous system
• MRCP offers the added benefit of possible
preoperative diagnosis of cyst-biliary fistula
• In one series, sensitivity and specificity were
reported as 78% and 100%, respectively for
diagnosis of cyst-biliary communication
Hosch W, Stojkovic M, Jänisch T, et al: MR imaging for diagnosing cysto-biliary
fistulas in cystic echinococcosis. Eur J Radiol 66:262, 2008
35.
36. Treatment
• Various options are available –
- Drug therapy
- Percutaneous interventions
- Endoscopic methods
- Surgical (open/lap)
37. Treatment
• Indications for drug therapy –
Adjuvant therapy with intervention- 4 days prior to
intervention and to continue it for 1 month
(albendazole) or 3 months (mebendazole) after the
intervention
Inoperable cysts
Multiple or multiorgan cysts
Recurrent hydatids
Surgically unfit patients
Cysts in lungs, bone, brain, eyes
38. Treatment - Albendazole
• Albendazole is administered in a dose of 10 – 15
mg/kg/day in adults or a fixed dose of 400 mg twice
daily
• The treatment is given in cycles of 28 days (1
cycle=28days) with two weeks treatment free
periods between the cycles
• Inoperable cases - as primary treatment - 3 cycles
• Pre-operatively – to reduce the risk of recurrence 6
weeks continuous treatment
• Post-operatively to prevent recurrence in cases of
intraoperative cyst spillage – 3 cycles
39. Treatment
• Side effects of Albendazole therapy
are -
mild abdominal pain, nausea, vomiting,
pruritis, dizziness, alopecia, rash and
headache. Occasionally leucopoenia,
eosinophillia, icterus, and mild elevation
in transaminase levels.
40. Treatment
• Contraindications of drug therapy-
Large cysts
Honeycomb cysts (with septae)
Infected cysts
Calcified cysts
Pregnancy
41. Treatment
• PAIR
• (Puncture – Aspiration – Injection –Reaspiration)
Indications-
Surgically unfit/ who refuses surgery
CL, CE 1, CE 2 and CE3
Relapse cysts after surgery
Infected cysts
In pregnant women
children less than 3 years
Cysts more than 5 cm in different liver segments
42. Treatment
• Results and problems of PAIR –
Complication rate—10-40%
Mortality rate—0.9-2.5%
Fever—35% - disappears in 72 hours
Anaphylaxis—0.1-0.2% Same as open surgery
drugs should be kept ready for anaphylaxis
Infection—10% well controlled by antibiotics
Local recurrences—4% (Repeat PAIR can be done)
43. Treatment
• Contraindications for PAIR
Inaccessible cysts
Superficially located cysts
Cysts with multiple septae—honeycomb cysts
Hyperechogenic cysts
Communicating cysts to bile duct
Calcified cysts
Cysts in the lung
44. HOW TO PERFORM PAIR?
• Basic Requirements:
• Trained personnel
• USG/CT guidence
• Ultrasound equipment (portable apparatus) with a
3.5 - 5 MHz probe
• Needles (lumbar puncture needles, “fine needles”,
especially for multiple daughter cysts)
• Catheters for large cysts (> 5 cm)
• 95 % alcohol or hypertonic (at least 15 %) saline as
protoscolicide agent
45. PAIR
• “Fast test” for checking the presence of bilirubin in
the cystic fluid (Dipstick test)
• Optic microscope
• Drugs to be used in case of allergic reactions-
anaphylaxis (epinephrine, hydrocortisone); basic
resuscitation equipment
• Blood pressure measurement and intravenous
catheter must be left in the forearm during the
procedure, so that resuscitation can take place
immediately, should the need arise
46. PAIR
• Done under US/CT guidance.
• Under local anaesthesia cyst is punctured using a
cholangiography 22 gauge needle through thickest route/part of
cyst wall.
• Cyst is entered through non-dependent wall and 50% of fluid
is aspirated. All multiple/daughter cysts are aspirated.
• Radiopaque dye is injected to see if any communications are
present. Scolicidal agents—15-20% hypertonic saline
is injected into the cyst. After 20 minutes reaspiration is done. A
sclerosant—alcohol is injected.
• If cyst is 6 cm or more, a drainage catheter is placed for 24
hours for complete drainage and later alcohol sclerosant is
injected (PAIRD)
47. Endoscopic treatment
• The Endoscopic management is useful in presence
of intrabiliary rupture, which requires exploration and
drainage of the biliary tract and also after surgery in
presence of residual hydatid material (membranes
and daughter cyst) left in biliary tree
• During the endoscopic exploration the biliary tree is
cleared of any hydatid material with a balloon
catheter or a dormia basket. The endoscopic
sphinterotomy is also performed to facilitate drainage
of the common bile duct.
48. Surgery
• Operative goal/principles-
(1) Inactivate infectious cyst contents (scolices and the
germinative membrane)
(2) Prevent spillage of cyst contents
(3) Evacuate all viable elements
(4) Manage the residual cavity
(5) Management of communication between cyst and
adjacent structures
-Debate continues regarding the extent of surgery and
optimal management of the cyst cavity.
49. Surgery
• surgery is increasingly being replaced by other
options in uncomplicated cysts,
• it maintains a central role in complicated cysts (i.e.,
rupture, biliary fistula, compression of vital
structures, superinfection, hemorrhage), cysts at
high risk of rupture, or large cysts with many
daughter vesicles that are not suitable for
percutaneous treatments.
Francesca Rinaldi World J Hepatol 2014 May 27; 6(5): 293-305
50. Surgery
• As a rule, perioperative ABZ prophylaxis, from 1 wk
prior to surgery until 4 wk postoperatively, is
necessary to minimize the risk of secondary
echinococcosis from seeding of protoscoleces in the
abdominal cavity
• Radical operations include formal anatomic resection
or pericystectomy. The latter involves removal of the
infected cyst, pericyst, and a margin of normal
surrounding hepatic parenchyma
• More conservative procedures seek to sterilize and
then evacuate cyst contents, leaving the pericyst
intact.
51. Surgery – Things to be
remembered
• Isolate the area- colored mops soaked with scolicidal
agent
• Aspiration of a small amount of fluid to reduce
pressure before opening it
• Scolicidal agent is then instilled into the cyst
• Total evacuation of infected contents
52. Surgery
• Management of remaining cavity
Marsupilization
Deroofing
Omentoplasty
Interoflexon
Capitonage
Drainage of cyst
53. Contraindication of surgery
• Complex or widespread affection
• Advanced patient age
• Pregnancy
• Severe comorbidities
• Multiple cysts that are difficult to access
• Partially inactive or calcified liver cysts
• Patient refusal of surgery
54. RADICAL OR CONSERVATIVE SURGICAL
TREATMENT?
• A comparative retrospective study of 242 patients
described significantly higher morbidity and
recurrence rates in patients who underwent
conservative surgery (11% vs 3%; 24% vs 3%)
Aydin et al , J Gastroenterol 2008
• Randomized study involving 32 patients, compared
radical surgery and conservative surgery. The
authors concluded that conservative surgery leads to
a significantly higher early recurrence rate (P =
0.045) compared to radical surgery, as well as a
higher rate of complications in the residual cyst
cavity (P = 0.011)
Yüksel O, J Gastrointest Surg 2008
55. ?Best after conservative surgery
• According to the RCT by Dziri et al omentoplasty
alone leads to fewer complications than external
drainage
Dziri C, Haouet K, Fingerhut A. Treatment of hydatid cyst of the liver:
where is the evidence? World J Surg 2004; 28:731-736
56. Is laparoscopic treatment safe?
All the studies reported have observed that a laparoscopic approach is safe for the
treatment of HC, with objectively low conversion rates and no mortality cases
60. Complication –surgery
• Biliary leakage is the most frequent postoperative
complication following surgery for hydatid cyst of
liver. It has been reported to occur in about 50% of
cases because of the small-undetected
communication between the cyst and the bile ducts
• The surgical management of hydatid disease of liver
carries a mortality rate of 0.9 to 3.6 % and
recurrence up to 11.3 % within 5 years. Operations
carry a progressively higher mortality – increasing
from 6 % after second to 20% after third.
61. Follow up
• Chemotherapy: Postoperative treatment with benzimidazoles
is continued for 1 month in patients with CE who have
undergone complete resection or PAIR successfully. The
treatment is continued for 3-6 months for patients with resected
AE, incompletely resected CE, spillage during surgery or PAIR,
and metastatic lesions.
• Laboratory tests: Patients on benzimidazoles should have a
CBC count and liver enzyme evaluation performed at biweekly
intervals for 3 months and then every 4 weeks to monitor for
toxicity. ELISA or indirect hemagglutination tests are usually
performed at 3-, 6-, 12-, and 24-month intervals as screening
for recurrence of resected disease or aggravation of existing
disease.
• Imaging: Ultrasonography and/or CT scan are used in follow-
up at the same intervals as the laboratory tests or as clinically
indicated.
62. Take home messege
• Antihelminthics serve as an important adjunct to
surgical or percutaneous therapies.Preoperative
albendazole is recommended by WHO as it reduces
the proportion of viable scolices at operation and
cuts postoperative recurrence rates by more than
50%
• Radical surgery is a better option than conservative
treatment ( LOE 2b, Rec class B)
• Omentoplasty associated with conservative surgical
treatment is effective in preventing postoperative
complications (LOE 2b, Rec class B)
• Percutaneous drainage combined with ALB therapy
is a better alternative of surgery whenever indicated
63. • Laparoscopic surgical approach for liver HC is safe
however more RCTs and prospective studies to
evaluate the value of Laparoscopic procedure need
to be conducted
• Antihelminthics (ALBZ) are contraindicated in
pregnancy and carry the risks of elevated liver
enzymes and bone marrow suppression
