Giant Hydatid Cystic Liver Disease: A Challenging Problem for Western Surgeons

May 25, 2007
Surgical Rounds®, May 2006, Volume 0, Issue 0

Ronald Barbosa, Chief Resident, Department of Surgery; Ahmed Mahmoud, Program Director, Department of Surgery; Nathaniel Matolo, Chairman, Department of Surgery; Sheela Kapre, Chairman, Department of Internal Medicine, San Joaquin General Hospital, French Camp, CA

Hydatid cystic liver disease is an infrequent but challenging problem for surgeons in the Western Hemisphere. With increasing immigration and travel, the geographical range of Echinococcus is expanding; thus, more surgeons may be faced with this kind of rare case. In many instances of hydatid cystic liver disease, computed tomography scans of the abdomen show the characteristic cystic appearance of scolices, and serological testing may not be needed. Medical therapy may be used for smaller, noncomplicated cysts, but surgical intervention remains the most definitive treatment. The authors report a case of giant hydatid cystic liver disease in a patient who had immigrated to the United States from Yemen many years earlier.

Ronald Barbosa, MD Chief Resident

Department of Surgery

Ahmed Mahmoud, MD Program Director

Department of Surgery

Nathaniel Matolo, MD Chairman

Department of Surgery

Sheela Kapre, MD Chairman

Department ofInternal Medicine

San Joaquin General Hospital

French Camp, CA

Although endemic in certain parts of the world, hydatid cystic liver disease is rarely encountered in the United States. New data suggest that Echinococcus granulosus, the causative tapeworm, is expanding its geo?graphical range in the Northern Hemi?sphere and its transmission is intensifying, especially in central Europe.1 In?ternational travel and immigration have also increased the possibility that physicians in nonendemic areas will encounter patients with hydatid cystic disease, which means this disease could have a wide global impact.2 Even though sur?gery is the mainstay of treatment, surgeons in the United States rarely have to deal with hepatic hydatid cysts. We report a case of giant hydatid cystic liver disease and provide a review of the literature in order to help surgeons in the Western Hemisphere handle this uncommon and challenging ailment.

Case report

A moderately obese 66-year-old wom?an went to her primary care physician because of a dull, aching pain in her right upper quadrant of 4 months' duration. She had occasional nausea but no other significant symptoms. She had no history of peptic ulcer disease or jaundice. The patient had not sought any medical care since the birth of her children many years earlier and did not report any comorbidities. She had immigrated to the United States from Yemen in 1987.

Physical examination elicited mild tenderness on palpation in the right upper quadrant. A complete blood count and liver function tests were unremarkable. A computed tomography (CT) scan of the abdomen and pelvis with intravenous contrast showed a 14-cm complex cyst that involved much of the right lobe of the liver. Numerous daughter cysts were evident, and a minimal amount of calcification was present (Figure 1). The cyst wall was adjacent to the pericardium, inferior vena cava, and the free peritoneal cavity (Figure 2). No pulmonary lesions were apparent on a chest radiograph. Serologic testing was not performed because the appearance of the cyst on the CT scan was thought to be specific for Echinococcus. Surgical consultation was requested.

The patient received albendazole perioperatively, and hydrocortisone was administered before inducing anesthesia. The cyst was approached through a right subcostal incision, and an accessible portion was found between the diaphragm and Couinaud segments IV and VIII. Surrounding structures were protected with laparotomy pads soaked with hypertonic saline (20%). The cyst was opened and a large amount of whitish gelatinous material, along with a large number of intact daughter cysts, were removed. A scolicidal agent (20% saline) was in?stilled into the cavity multiple times. Desiccation of the surrounding tissue was not observed, nor was there any gross spillage of cyst contents. The free portion of the cyst wall was excised. The argon beam coagulator was used to lightly cauterize the entire surface of the cyst, except the portion adjacent to the vena cava. This was done in an effort to kill any remaining scolices and seal small biliary leaks. A closed suction drain was left in the cavity, which was then packed with omentum.

Histopathological examination of the specimen revealed the characteristic features of hydatid cyst (Figure 3). The viable cyst was filled with colorless fluid known as the hydatid sand, which contains daughter cysts and brood capsules with scolices. Scolices can be identified by their characteristic hooklets, which are 20 to 40 ?m in length.

The patient did well postoperatively. The drain had no significant output and was removed before she was discharged home 4 days after surgery. Alben?dazole was continued for 1 month postoperatively. At 2-month follow-up, a CT scan of the abdomen showed obliteration of the cavity from excision of the cyst (Figure 4). The patient was doing well and had re?sumed full activities.


Hydatid disease, or echinococcosis, is endemic in areas of the world such as North Africa, Greece, Turkey, South America, and the Middle East, where it is usually promptly recognized.1 Virtually all studies on echinococcosis have originated from institutions in these areas. The incidence of echinococcosis in the United States is unknown, but it is seen infrequently. One review of 15 years of surgical management of liver cysts at a large tertiary center found only eight cases of echinococcosis.2 One tertiary center in the United Kingdom saw 30 cases in a 16-year period.3 A larger number of cases of hydatid cystic disease may be expected in the coming years as more individuals travel from endemic regions to the United States.


Hydatid disease is most commonly caused by infestation with the larval form of the tapeworm E .1,4 Dogs are the definitive host, and thousands of eggs are released into the feces of infected animals.1 Sheep, cattle, or goats may act as intermediate hosts, and the larvae, or protoscolex, can multiply in these animals but are contained in a hydatid cyst. Adult worms are not formed until the larvae are ingested by dogs. Humans act as an accidental intermediate host, with ingestion of contaminated vegetables being the most common cause of infestation.1

Once ingested, eggs can penetrate the mucosa of the small intestine and pass into the portal circulation.1,4 Most scolices remain in the liver, although some may reach the lungs and other organs. As the larvae multiply, the hydatid cyst enlarges, but systemic reactions are rare since the outer shell of the cyst separates from the systemic circulation.1 Symp?toms commence gradually and are due to displacement of normal tissue by the cyst. On average, cysts expand about 1 cm per year, but expansion may be halted al?together if complete calcification of the cyst wall occurs.1,4

A hydatid cyst is surrounded by the pericyst, which is comprised of compressed fibrous tissue of host origin that is not separable from the normal organ parenchyma.1 The parasite itself is covered by a thin, whitish laminar membrane through which the larvae receive nutrients from the host. Inside the laminar membrane is the germinative membrane in which division of scolices occurs. These are then released into the hydatid fluid. Daughter cysts may be created when portions of the germinative membrane break off into the cyst fluid.1

In endemic areas, ultrasonography is the most common imaging modality used.5 CT scanning is also helpful and provides more information, but in re?gions with limited access to this modality, ultrasonography is thought to be sufficient. Plain radiographs are usually not helpful.1 Angiography may yield striking images but is rarely necessary.1

Anaphylactic reactions have been caused by systemic exposure to hydatid cyst fluid, but are relatively rare.1,6 These may occur from spontaneous intraperitoneal rupture of a cyst or from intraoperative spillage. The benefit of premedication with a single dose of 100 mg hydrocortisone is controversial.1 Med?ica?tions for treatment of a severe IgE-mediated response (epinephrine, antihista?mines, and steroids) should be available.6

Medical therapy alone has been used in cases of uncomplicated infection, with success rates between 30% and 70%.4 Albendazole and mebendazole have been used, but albendazole has better efficacy and bioavailability. Pro?longed treatment may be required and relapses may occur.4 Patients may be followed with serial imaging studies and serologic titers.

Surgical intervention is the definitive treatment for hydatid cystic disease but in certain instances may not be necessary. Cysts smaller than 4 cm or those situated deep within the liver parenchyma can be observed over time with serial ultrasonography examinations every 6 months.1 When the cysts grow to sufficient size and become more superficial, surgery can be considered. Cyst calcification indicates that the cyst has stopped growing and that there are rarely any clinical sequelae. Thus, such cysts can usually be managed expectantly.1 In general, all other patients with hydatid cysts of the liver should undergo surgery because of the local destruction of liver parenchyma and the possibility of biliary complications, superinfection, and intra?peritoneal dissemination.

Hydatid cysts of the liver are usually approached through the abdomen, though cysts located primarily in the superior aspect of the liver may be approached through the chest.1 Once the superficial portion of the cyst is located, the surrounding tissues are protected by packing them off with laparotomy pads. The incision's edges must be protected as well. The purpose of packing off is to prevent contamination with spilled cyst fluid and protect the tissues from the scolicidal agent.

Internal cyst pressure may reach 100 mm Hg, so decompression is usually performed.1 A large bore angiocatheter, suction trocar, or other similar device may be used. If the cyst is multivesicular, decompression by these means may not be possible. Once the cavity is partially decompressed, the cyst edges are grasped with clamps and elevated to prevent spillage.

The contents of the cyst are then removed. Univesicular cysts have a laminated membrane that should be removed along with the cyst fluid. For multivesicular cysts, the gelatinous cyst contents and numerous daughter cysts must be scooped out. Evacuation of cyst contents must be meticulous, and no parasitic material should remain. At the end of this process, any visible bile duct openings may be closed with absorbable sutures.1

A scolicidal solution is then instilled into the pericystic cavity. Hypertonic saline may be used. The optimal concentration for killing scolices without being too desiccating is unknown, but concentrations between 5% and 20% have been reported. Freshly prepared 0.5% silver nitrate is inexpensive and nontoxic.1 Use of 95% ethanol has been described.7 Sodium hypochlorite can dissolve cyst membranes in vitro, but clinical experience is limited.8

Several options exist for managing the remaining cyst cavity, as described in a review by Saidi.3 The opening can be sutured closed; left wide open to the peritoneal cavity; packed with omentum; or closed over a large drain, which remains in place for several months. Marsu?pia?l?ization is strongly discouraged because it may cause a chronic wound that is difficult to manage.1 Packing the cavity loosely with omentum may prevent small bowel migration into the cavity with subsequent obstruction1 and seems to be the most popular strategy in Greece and Turkey.5,9

Other surgeons attempt to remove the entire pericyst with a rim of normal liver parenchyma, even if major liver resection is required.10 With either approach, operative management becomes more complex if the cyst has ruptured into the biliary system.1,5,10 Cysts may also spon?taneously drain through the diaphragm into the pleural cavity. These techniques, however, are beyond the scope of this paper.

Percutaneous drainage of hydatid cysts has become more popular. This is usually referred to as the puncture, aspiration, injection, and re-aspiration (PAIR) technique.1,6,7,11 Cysts are aspirated under ultrasonography or CT guidance, and standard scolicidal agents are instilled. Anaphylactic reactions are rare.6,7 Long-term efficacy is unknown, and some surgeons in endemic areas are hesitant to use the technique.6 It is generally agreed that large, complex, or multivesicular cysts require an open approach.1,4,5

Postoperatively, patients continue to receive albendazole therapy for at least 1 month, and serial ultrasonography or CT examinations and serologic testing are conducted to check for recurrence of the disease.4 In up to 50% of patients, collapse of the cyst cavity is not complete, and serologic tests may remain positive.9 Albendazole therapy may be extended for these patients, and complete cyst obliteration may not be seen for 2 to 3 years.9 Long-term recurrence rates are unknown, but about 10% of patients in some series have had documented recurrent disease within 3 years.3,5


Hydatid cysts are seen infrequently in the United States; however, with increasing immigration, worldwide travel, and more frequent use of imaging studies, surgeons may encounter more cases in the future. In addition, Echinococcus species are thought to be expanding their geographical range and variety of hosts.12 Fortunately, the diagnosis is usually straightforward and surgical management follows a set of simple rules.1


1. Romig T. Epidemiology of echinococcosis. Langenbecks Arch Surg. 2003;388(4):209-217.

2. Yaghan R, Heis H, Bani-Hani K, et al. Is fear of anaphylactic shock discouraging surgeons from more widely adopting percutaneous and laparoscopic techniques in the treatment of liver hydatid cyst? Am J Surg. 2004;187(4):533-537.

3. Saidi F. Echinococcal cysts: etiology, diagnosis, complications, and medical and surgical treatment. In: Baker RJ, Fischer JE, eds. Mastery of Surgery. 4th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2001:1035-1043.

4. Regev A, Reddy KR, Berho M, et al. Large cystic lesions of the liver in adults: a 15-year experience in a tertiary center. J Am Coll Surg. 2001;193(1):36-45.

5. Baden LR, Elliott DD. Case records of the Massachusetts General Hospital. Weekly clinicopathological exercises. Case 4-2003. A 42-year-old woman with cough, fever, and abnormalities on thoracoabdominal computed tomography. N Engl J Med. 2003;348(5):447-455.

6. Silva MA, Mirza DF, Bramhall SR, et al. Treatment of hydatid disease of the liver. Evaluation of a UK experience. Dig Surg. 2004;21(3): 227-233.

7. Yorganci K, Sayek I. Surgical treatment of hydatid cysts of the liver in the era of percutaneous treatment. Am J Surg. 2002;184(1): 63-69.

8. Filice C, Brunetti E. Use of PAIR in human cystic echi?nococcosis. Acta Trop. 1997;64(1-2):95-107.

9. Karaoglanoglu M, Akinci OF, Bozkurt S, et al. Effect of different pharmacologic and chemical agents on the integrity of hydatid cyst membranes. AJR Am J Roentgenol. 2004;183(2):465-469.

10. Bozkurt B, Soran A, Karabeyoglu M, et al. Follow-up problems and changes in obliteration of the residual cystic cavity after treatment for hepatic hyatidosis. J Hepatobiliary Pancreat Surg. 2003;10(6):441-445.

11. Moreno Gonzalez E, Meneu-Diaz JC, Moreno-Elola A. Echinococcal cysts: personal approach to the surgical treatment of echinococcal cysts. In: Baker RJ, Fischer JE, eds. Mastery of Surgery. 4th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2001:1043-1045.

12. Acunas B, Rozanes I, Celik L, et al. Purely cystic hydatid disease of the liver: treatment with percutaneous aspiration and injection of hypertonic saline. Radiology. 1992;182(2):541-543.