hydatid cyst of liver for surgeons and medical students

1. HYDATID CYST

2. DR.SYED UBAID
M.S(KEM MUMBAI)
FMAS
LAPAROSCOPIC AND GENERAL
SURGEON
ASSOCIATE PROFESSOR OF SURGERY
IIMSR,JALNA

3. HYDATID DISEASE
Echinococcosis (hydatid disease) is a zoonosis
caused by the larval stage of Echinococcus
granulosus.
 Humans are accidental intermediate hosts,
whereas animals can be both intermediate
hosts and definitive hosts.

4. HYDATID DISEASE
The two main types of hydatid disease are caused
by E. granulosus and E. multilocularis. The former
is commonly seen in the Mediterranean, South
America, the Middle East, Australia, and New
Zealand, and is the most common type of hydatid
disease in humans.
 In humans, 50–75% of the cysts occur in the liver,
25% are located in the lungs, and 5–10%
distribute along the arterial system. Infection
with echinococcal organisms is the most common
cause of liver cysts in the world.

5. Echinococcus granulosus

6. Etiology
 The life cycle of E. granulosus has two hosts.
 The definitive host is usually a dog or some other
carnivore.
 The adult worm of the parasite lives in the proximal
small bowel of the definitive host attached by hooklets
to the mucosa.
 Eggs are released into the host's intestine and
excreted in the feces.
 Sheep are the most common intermediate host, and
these animals ingest the ovum while grazing.

7. Etiology
 The ovum loses the protective chitinous layer
and is digested in the duodenum.
 The released hexacanth embryo (oncosphere)
passes through the intestinal wall into the
portal circulation and develops into cysts
within the liver.
The definitive host eats the viscera of the
intermediate host and the cycle is completed.

8. Etiology
 Humans may become intermediate hosts through
contact with the definitive host (usually a dog) or by
ingestion of contaminated water or vegetables.
 Once in the liver, cysts grow to 1 cm in the first 6
months and 2–3 cm annually thereafter, depending on
host tissue resistance.
 Once the parasite passes through the intestinal wall
into the portal venous or lymphatic system, the liver
acts as the first line of defense, and thus is the most
frequently involved organ.
 The right lobe of the liver is the most commonly
involved.

9. Life Cycle of E granulosus

10. Incidence
Hydatid liver disease affects all age groups, both
sexes equally, and no predisposing pathologic
conditions are associated with infection.
Washing hands after contact with canines,
eliminating the consumption of vegetables grown
at ground level from the diet, and stopping the
practice of feeding entrails of slaughtered animals
to dogs have all aided in decreasing the incidence
of the disease.

11. Pathology

12. Pathology
• Hydatid liver cysts tend to expand slowly and
without symptoms and are thus frequently
very large on presentation. Single lesions are
noted in 75% and are predominantly located
within the right lobe (80%). Even though the
lesion is single, half contain daughter cysts
and are multilocular.

13. Pathology
• The typical hydatid cyst has a three-layer wall surrounding a
fluid cavity. The outer layer is the pericyst, a thin, indistinct
fibrous tissue layer representing an adventitial reaction to
the parasitic infection. The pericyst acts as a mechanical
support for the hydatid cyst and is the metabolic interface
between the host and the parasite. As the cyst grows, bile
ducts and blood vessels stretch and become incorporated
within this structure, which explains the biliary and
hemorrhagic complications of cyst growth and difficulties
with resection. Over time, the pericyst calcifies.

14. Hydatid Cyst Structure
• The hydatid cyst has three layers:
(a) the outer pericyst, composed of modified host cells
that form a dense and fibrous protective zone;
(b) the middle laminated membrane, which is acellular
and allows the passage of nutrients;
(c) the inner germinal layer, where the scolices (the
larval stage of the parasite) and the laminated
membrane are produced.

15. • Daughter vesicles (brood capsules) are small
spheres that contain the protoscolices and
are formed from rests of the germinal layer.
Before becoming daughter cysts, these
daughter vesicles are attached by a pedicle
to the germinal layer of the mother cyst. At
gross examination, the vesicles resemble a
bunch of grapes.

16. Cyst layers and contents

18. Clinical Presentation
• The clinical features of hydatid liver disease
depend on the site, size, stage of development,
whether the cyst is alive or dead, and whether
the cyst is infected or not.Pain in the RUQ or
epigastrium is the most common symptom,
whereas hepatomegaly and a palpable mass are
the most common signs.

19. Clinical Presentation
SYMPTOMS Percentage
Asymptomatic 75%
Abdominal pain 20%
Dyspepsia 13 %
Fever and chills 8 %
Jaundice 6%

20. Clinical Presentation
• SIGNS
Right upper quadrant mass 70%
Right upper quadrant tenderness 20%
LABORATORY DATA
Eosinophilia 35%
Bilirubin >2 mg/Dl 20%
WBC count <10,000/mm3 10%

21. Casoni or intradermal test
oIndirect hemagglutination test and
enzyme-linked immunosorbent assay
are the most widely used methods for
detection of anti-Echinococcus
antibodies (immunoglobulin G
[IgG]).These tests give false positive
results in cases of schistosomiasis and
nematode infestations that is why
they are not specific for diagnosing
hydatidosis.

22. • Immunoelectrophoresis : depends on
the formation of specific arc of
precipitation ( called arc 5 ) which is
highly specific and can be used to
exclude cross-reactions caused by
noncestode parasites

23. Radiology
• Chest radiographs may show an elevated
diaphragm and concentric calcifications in the
cyst wall, but are of limited value.
• Classic findings of hydatid cysts are calcified
thick walls, often with daughter cysts.

24. X RAY

26. Radiology
• Ultrasound and CT are considered the first choice for imaging.
Ultrasound defines the internal structure, number, and location of
the cysts and the presence of complications. The specificity of
ultrasound in hydatid disease is around 90%.
• The classification
Type I Pure fluid collection.
Type II Fluid collection with a split wall (floating membrane).
Type III Fluid collection with septa (honeycomb image).
Type IV Heterogenous echographic patterns
Type V Reflecting thick walls.

29. Computed tomography
Computed tomography gives similar
information to ultrasound, but more specific
information about the location and depth of
the cyst within the liver. Daughter cysts and
exogenous cysts are also clearly visualized,
and the volume of the cyst can be estimated.
CT is imperative for operative management,
especially when a laparoscopic approach is
utilized.

33. MRI &ERCP
• MRI provides structural details of the hydatid
cyst, but adds little more than ultrasound or
CT, and is more expensive. Endoscopic
retrograde cholangiopancreatography (ERCP)
may show communication between the cysts
and bile ducts and can be used to drain the
biliary tree before surgery.

36. Treatment
• Most echinococcal cysts are asymptomatic on presentation,
but complications such as pulmonary infection, cholangitis,
rupture, and anaphylaxis give good reason to consider
treatment for all.
• Medical, surgical, and percutaneous approaches may be
part of the treatment armamentarium.
• Small cysts (<4 cm) located deep in the parenchyma of the
liver, if uncomplicated, can be managed conservatively.
Basic principles of treatment ar
(1) eradication of the parasite within the cyst,
(2) protection of the host against spillage of scoleces, and
(3) management of complications.

37. Anthelmintics
• Medical therapy for echinococcosis is limited to
the benzimidazoles (mebendazole and
albendazole) and used alone is only 30%
successful.
• Albendazole is readily absorbed from the
intestine and metabolized by the liver to an active
form.
• Mebendazole is poorly absorbed and is
inactivated by the liver.

38. Anthelmintics
 Albendazole is thus the drug of choice for medical
therapy.
 Given for at least 3 months preoperatively,
albendazole reduces the recurrence rate when
cyst spillage, partial cyst removal, or biliary
rupture has occurred.Duration of therapy in these
instances is at least 1 month Postoperatively.
 Albendazole is administered in several 1-month
oral doses (10-15 mg/kg/d) separated by 14-day
intervals.

39. The PAIR technique (percutaneous
aspiration, injection and re-aspiration)
The most frequently utilized protoscolecidal agents
1. 15–20% saline,
2. 95% ethanol,
3. a combination of 30% saline and 95% ethanol, and
4. mebendazole solution.
Complications
o Spillage,
o anaphylaxis, and
o recurrence

41. Surgery
• Surgery is still the treatment of choice for
uncomplicated hydatid disease of the liver.
• The objectives of surgical treatment are to:
(1) inactivate the scoleces,
(2) prevent spillage of cyst contents,
(3) eliminate all viable elements of the cyst, and
(4) manage the residual cavity of the cyst.

42. Scolecidal Agents
• Early on, surgical management of hydatid cysts
via cyst evacuation resulted in a high rate of
peritoneal implantation. This problem prompted
the use of scolecidal agents for injection into the
cyst and for use in the surrounding peritoneum.
Formalin, hypertonic saline, cetrimide, hydrogen
peroxide, polyvinylpurrolidone-iodine, silver
nitrate, and ethyl alcohol are among some of the
many agents that have been used.

47. OMENTOPLASTY

48. MARSUPILIZATION

49. CAPETONAGE

50. PERICYSTECTOMY

51. HEPATECTOMTY

52. LAPAROSCOPY

53. Complications
• Ruptures
• Secondary infection,
• Anaphylactic shock, and
• liver replacement, in order of decreasing
frequency.

54. THANK YOU