1. Hydatid Liver Cyst Dr Mohammad sadra nazari
Presented By:
Dr Mohammad sadra nazari
Qazvin Univercity Of Medical Scince
GENERAL SERGEON
Hydatid Liver Cyst

2. Introduction
Echinococcosis (hydatid disease) is a zoonosis caused by the larval stage of Echinococcus granulosus. Humans are accidental intermediate hosts, whereas animals can be both.
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.

3. Morphology Only 2-8 mm long Usually comprises of- Scolex neck
immature proglottid
mature proglottid
gravid proglottid

4. commonly seen in the Mediterranean, South America, the Middle East, Australia, and New Zealand… .

5. 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 .
Eggs excreted in the feces.
Sheep are the most common intermediate host, and ingest the ovum. The ovum loses the protective chitinous layer.
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

7. Humans may become intermediate hosts through contact with the definitive host (usually a dog) or by ingestion of contaminated water or vegetables.
passes through the intestinal wall into the portal venous or lymphatic system.
in the liver, cysts grow to 1 cm in the first 6 months and 2–3 cm annually thereafter.
The right lobe of the liver is the most commonly involved.

8. Incidence
The incidence of hydatid liver cysts in the United States is approximately cases per year.
Hydatid liver disease affects all age groups, both sexes equally.
Public education about the life cycle and transmission .
Washing hands after contact with canines, eliminating the consumption of vegetables grown at ground level , and stopping feeding entrails of slaughtered animals to dogs have all aided in decreasing the incidence of the disease.

9. Pathology
Hydatid liver cysts tend to expand slowly and are thus frequently very large on presentation.
Single lesions are noted in 75% and located within the right lobe (80%).

10. Hydatic 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.

11. Pathology
The outer layer is the pericyst, a thin, indistinct fibrous tissue layer representing an adventitial reaction to the parasitic infection.

12. Pathology
As the cyst grows, bile ducts and blood vessels stretch and become incorporated within this structure. Over time, the pericyst calcifies.
The Secound is laminated membrane and The pericyst acts as a mechanical support for the hydatid cyst and is the metabolic interface between the host and the parasite.
is bluish-white, gelatinous, and about 0.5 cm thick. This membrane is a cuticular chitinous structure without nuclei and acts as a barrier for bacteria and an ultrafilter for protein molecules.

13. Pathology
The inner layer or endocyst is the germinal membrane, responsible for the production of clear hydatid fluid, the ectocyst, brood capsules, scoleces, and daughter cysts.
The endocyst is 10–25 m thick and attached tenuously to the laminated membrane. The absorptive function of the inner layer is important for the nutrition of the cyst.

14. Pathology brood capsules fomation
The inner layer also has a proliferative function producing the ectocyst and scoleces.
This germinal layer forms small cellular masses that give rise to brood capsules, in which future worm heads develop.
They enlarge and develop into invaginated protoscoleces.

15. Pathology Hydatid Sand
Brood capsules and freed protoscoleces are released into the fluid of the original cyst and together with calcareous bodies, form hydatid sand.
Hydatid sand is made up of around 400,000 scoleces per milliliter of fluid.

16. Pathology The protoscolex can differentiate in two directions.
In the definitive host, the scolex becomes an adult tapeworm.
In the intermediate host, including humans, each of the released protoscoleces is capable of differentiating into a new hydatid cyst.

17. Pathology
Daughter cyst formation is a defense reaction. Hydatid cysts in humans are long- standing, large, and liable to injury. Any injury may cause daughter cyst formation, and their size and number are variable.
In uncomplicated cysts, the cyst cavity is filled with sterile, colorless, antigenic fluid containing salt, enzymes, proteins, and toxic substances.
The formation of daughter cysts is called endogenic vesiculation.

18. Diagnosis
The diagnosis of uncomplicated hydatid disease of the liver depends on the clinical suspicion.
Uncomplicated hydatid cysts of the liver are usually asymptomatic. Symptoms may be secondary to a toxic reaction from the presence of the parasite, or the local mechanical effects.

19. Clinical Presentation
The clinical features of hydatid liver disease depend on:
the site, size.
Pain in the RUQ or epigastrium is the most common symptom, whereas hepatomegaly and a palpable mass are the most common signs. Nonspecific fever, fatigue, nausea, and dyspepsia may also be present.
Approximately one-third of patients will have eosinophilia, and only 20% will present with jaundice and hyperbilirubinemia.

21. Asymptomatic 75% Eosinophilia 35% SYMPTOMS LABORATORY DATA
Abdominal pain %
Bilirubin >2 mg/dL %
Dyspepsia %
WBC count <10,000/mm %
Fever and chills %
Jaundice %
SIGNS
Right upper quadrant mass %
Right upper quadrant tenderness 20 %

22. Serology
No single biochemical test definitively establishes the diagnosis.
The Casoni and Weinberg tests are no longer used due to their low sensitivities.
In the uninfected people ,>18% false positive

23. Serology
Determination of specific antigens and immune complexes of the cyst with enzyme-linked immunosorbent assay (ELISA) give a positive result in more than 90% of patients.
Specific IgE antibodies are demonstrated with ELISA if active disease is present.
The arc 5 antibody test involves precipitation during immunoelectrophoresis of the blood of patients with the antigen. Positivity for this test is 91%.

24. Radiology
Chest radiographs may show an elevated diaphragm and concentric calcifications in the cyst wall, but are of limited value.

25. Radiology
Ultrasound and CT are considered the first choice for imaging.
Classic findings of hydatid cysts are calcified thick walls, often with daughter cysts.
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%.

26. Differential Imaging and Character of Hepatic Cysts
Pyogenic
Amebic
Hydatic
Congenital
Cystadenoma
Number
Single or multiple
One or few
Usually single
Single with loculations
Wall thickness
thick
thin
variable
Wall character
Uniform or multiloculated
Usually uniform
Uniform, daughter cysts; 50% calcified
Uniform
Septations common may be irregular
Cyst contents
Usually pus with blood
Red-brown; like anchovy paste
Clear or bilious; gelatinous
Usually clear water density
Usually green-brown mucinous

27. Radiology
Computed tomography gives more specific information about the location and depth. Daughter cysts are also clearly visualized, and the volume of the cyst can be estimated.
CT is imperative for operative management.

31. Radiology
MRI provides structural details of the hydatid cyst, but adds little more than ultrasound or CT, and is more expensive.
ERCP may show the bile duct anatomy and communication between the cysts and bile ducts and can be used to drain the biliary tree before surgery.

32. Treatment
Most cysts are asymptomatic, but complications such as pulmonary infection, cholangitis, rupture, and anaphylaxis give good reason to consider treatment.
Medical, surgical, and percutaneous approaches may be part of the treatment.

33. Treatment (1) eradication of the parasite within the cyst
Small cysts (<4 cm) located deep the liver, if uncomplicated, can be managed conservatively. Basic principles of treatment are:
(1) eradication of the parasite within the cyst
(2) protection of the host against spillage of scoleces, and
(3) management of complications.

34. Treatment
Anthelmintics
Medical therapy for echinococcosis is limited to mebendazole and albendazole and used alone is only 30% successful.
Albendazole is readily absorbed from the intestine and metabolized by the liver. Mebendazole is poorly absorbed and is inactivated by the liver. Albendazole is choice for medical therapy.

35. Treatment 10 mg/kg or 400mg BID
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.

36. Treatment Percutaneous Aspiration and Drainage(PAIR):
. In 1983, Fornage challenged this axiom and reported an accidental puncture of a hydatid cyst by US that had no clinical consequences.
The most frequently, a combination of 30% saline and 95% ethanol, and mebendazole solution.
The PAIR technique (percutaneous aspiration, injection and re-aspiration) has also been combined with albendazole therapy with 70% success rates and a low rate of recurrence..

37. Treatment Indications :
Type 1,2 cyst, suspected fluid collection, infected hydatid cysts, inoperable patients,pregnant women & patients with multiple & disseminated & symptomatic cysts.
contraindications:
Type 3& 4 cysts,ruptured liver cysts intothe biliary system or peritoneum, cysts inaccessible topuncture & children younger than 3years.

38. Percutaneous Aspiration and Drainage(PAIR):
Recurrence rates vary between 0 and 4%.
overall complication rates range from 15 to 40%.
major complications:
(anaphylactic shock) are rare( %).
minor complications:
(urticarial,itching,hypotension,fever,infection,fistula, rupture into the biliary system)range from 10 to 30%.

39. Treatment Surgery (2) prevent spillage of cyst contents,
Surgery is 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,
(4) manage the residual cavity of the cyst.

40. Treatment
one of the most important end points of hydatid cyst surgery may be recurrence. dissemination of protoscoleces-rich fluid during surgery and incomplete removal of the germinative memberane from the cyst cavity is a major cause of recurrence( %) of postoperative cases.
Scolicidal agents: according to WHO, ethanol(70-95%), hypertonic saline(15-20%), cetrimide solution(0.5%) & recently chlorhexidine gluconate0.04% was found tobe nontoxic without harmful effects & 100% effective on protoscoleces
Open-cyst evacuation
Laparoscopic cyst evacuation
Pericystectomy
Liver resection/Transplantation

43. Complications
Complications from hydatid cysts are seen in one-third of patients.
Most commonly, the cyst ruptures , followed by secondary infection, anaphylactic shock.
Viable hydatid cysts are space-occupying lesions with a tendency to grow. ,symptoms depend on the site and size of the cyst.
Symptoms result from direct pressure or distortion of neighboring structures or viscera. Compressive atrophy of the surrounding hepatocytes and fibrosis occurs, and these cysts may grow to such an enormous size that they replace an entire lobe.

44. Complications As the cysts enlarge, they may also rupture.
A communicating rupture is a rupture into the biliary or bronchial tree.
T-tube drainage, cystojejunostomy, and choledochoduodenostomy are the main operations performed for this pathologic condition.
A free rupture occurs when hydatid contents rupture throughout the peritoneal, pleural, or pericardial cavity. Acute symptomatic rupture into the peritoneal cavity occurs in 1–4% of patients and may precipitate anaphylactic shock.

45. Outcome
Medical therapy used alone results in recurrence rates of 70–80% and is not recommended.
Medical treatment is used in combination with a drainage procedure or in patients that are not surgical candidates.
Uncomplicated cases that undergo open surgical, laparoscopic, and percutaneous drainage have recurrence rates around 10%.

46. Outcome
Uncomplicated cases undergoing elective procedures such as laparoscopic or percutaneous cyst aspiration should have morbidity rates between 15% and 30%.
In patients with complicated disease that requires open evacuation, pericystectomy, or resection, morbidity is as high as 50%; however, mortality should still remain less than 5%.
Septic shock, peritoneal rupture, and comorbid conditions (i.e., malnutrition) play a major role in increasing mortality rates.

47. Thank you