Echinococcus of the liver

Advances in liver echinococcosis: diagnosis and treatment

Echinococcosis or hydatid cyst disease is a zoonosis caused by the larval cestode Echinococcus granulosus. It consists of a parasitic tapeworm disease affecting mainly liver. Nevertheless, the disease might well spread to more unusual sites such as lungs and brain. The definitive diagnosis of liver echinococcosis requires a combination of imaging, serologic, and immunologic studies. Despite the fact that a number of scolecoidal agents have been developed against liver hydatid disease, the cornerstone of the definitive treatment remains surgery. Both the classic surgical techniques and the recently developed minimally invasive and laparoscopic methods target the eradication of the disease by simultaneously avoiding perioperative spillage and dissemination or recurrence of echinococcosis. The present article constitutes a review of the biology of the parasite as well as the epidemiology, diagnosis, and therapeutic options of the liver hydatid disease.

Hydatid disease of the abdomen and other locations

We present patients treated for hydatid disease in our hospital (in northeastern Greece) over the last 20 years. In the period from 1984 to 2003, a total of 135 patients (54 male, 81 female) were treated for echinococcal disease (age 15-85 years). In 111 (82.2%) patients only the liver was affected; 9 (6.7%) patients had concomitant hepatic and extrahepatic hydatid disease; and 15 (11.1%) patients had only extrahepatic disease. Clinical symptoms in patients with hepatic locations of the disease included abdominal pain localized in the epigastrium or right upper quadrant of the abdomen, tenderness, hepatomegaly with palpable abdominal mass, jaundice, fever, and anaphylactic reaction. All the patients were treated surgically. Surgical techniques included partial cystectomy and drainage, cystectomy and capitonage, cystectomy and omentoplasty, only drainage, left lateral hepatectomy, total pericystectomy, and laparoscopic pericystectomy. Rupture into the bile duct was managed by T-tube drainage or biliodigestive anastomosis. Symptoms and surgical treatment for extrahepatic cysts varied according to the location of the cyst. The median cyst diameter of all patients was 11 cm. The postoperative complication rate was 17.0%. Two patients died (1.5%). The median hospital stay was 18 days. The recurrence rate was 6.7%. The study suggests that treatment of this benign disease should be the less radical surgical technique combined with pre- and postoperative anthelmintic administration. The surgical treatment should be combined with careful use of scolicidal fluids and aspiration of the cyst to avoid contamination and minimize the risk of recurrence.

Changing concepts in the management of liver hydatid disease

Hydatid disease is a rare entity primarily affecting the population of developing countries. The parasite shuttles between the liver and lungs. but almost any organ can be invaded, forming cysts. Septation and calcification of the cysts with a high antibody titre in the patient's serum confirm the diagnosis, although more sophisticated tests have been applied recently. Surgery constitutes the primary treatment, with a variety of techniques based on the principles of eradication and elimination of recurrence by means of spillage avoidance. Minimally invasive techniques and percutaneous drainage of the cysts are now feasible because of progress in the field. The aim of this review is to collect the experience from three different institutions and to provide practical guidelines for diagnostic and therapeutic strategies.

Longstanding liver cysts and obstructive jaundice

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Percutaneous drainage compared with surgery for hepatic hydatid cysts

BACKGROUND

In recent years percutaneous drainage has been used successfully to treat the hepatic hydatid cysts of echinococcal disease. We performed a controlled trial to compare the safety and efficacy of percutaneous drainage with those of surgical cystectomy, the traditional treatment.

METHODS

In a prospective study, we randomly assigned 50 patients with hepatic hydatidosis to treatment with percutaneous drainage (25 patients) or cystectomy (25). Albendazole (10 mg per kilogram of body weight per day for eight weeks) was administered to the patients who underwent percutaneous drainage. Serial assessments included clinical and biochemical examinations, ultrasonography, and serologic tests of echinococcal-antibody titers.

RESULTS

The mean (+/-SD) hospital stay was 4.2+/-1.5 days in the drainage group and 12.7+/-6.5 days in the surgery group (P<0.001). Over a mean follow-up period of 17 months, the mean cyst diameter decreased from 8.0+/-3.0 to 1.4+/-3.5 cm (P<0.001) after percutaneous drainage and from 9.1+/-3.0 to 0.9+/-1.8 cm (P<0.001) after surgery. The final cyst diameter did not differ significantly between the two groups (P=0.20). The cysts disappeared in 22 patients (88 percent) in the drainage group and in 18 (72 percent) in the surgery group (P=0.29). After an initial rise, the echinococcal-antibody titers fell progressively and at the last follow-up were negative (<1:160) in 19 patients (76 percent) in the drainage group and 17 (68 percent) in the surgery group (P=0.74). There were procedure-related complications in 8 patients (32 percent) in the drainage group and 21 (84 percent) in the surgery group, 17 of whom had fever postoperatively (P<0.001).

CONCLUSIONS

Percutaneous drainage, combined with albendazole therapy, is an effective and safe alternative to surgery for the treatment of uncomplicated hydatid cysts of the liver and requires a shorter hospital stay.

Treatment of experimental alveolar echinococcosis with albendazole: a 1H NMR spectroscopic study

The Meriones unguiculatus (jird) – Echinococcus multilocularis host–parasite model was used to evaluate metabolic changes in livers and cysts treated with albendazole (ABZ). Hydrogen-1 nuclear magnetic resonance spectra of liver extracts showed that livers of uninfected jirds fed olive oil contained more glycine but less glycerophosphocholine (GPC) than those of uninfected untreated controls. When ABZ was added to the olive oil and tested on uninfected animals, other modifications in the metabolic profile of the liver could be seen. While the concentration of GPC stayed reduced and that of glycine reverted to normal, the levels of glycogen, phosphocreatine/creatine (PCr/Cr), succinate, and acetate were lower than those in the normal liver. The metabolic pathology in this organ was further magnified in jirds infected with E. multilocularis. In this case, the liver was depleted of glycogen, glucose, taurine, GPC, and acetate, but had more betaine, phosphocholine, choline, PCr/Cr, and succinate. These abnormalities were markedly diminished by ABZ treatment, with only glycogen, GPC, and acetate concentrations being low when the treatment was terminated. Also, the drug suppressed the growth of the parasite by 75%, and extracts of these parasite cysts contained less glycogen, glycine, succinate, acetate, and alanine but more taurine, GPC, and PCr/Cr than extracts of those from untreated hosts.