Albendazole--objective evidence of response in human hydatid disease

Systemic and Target-Site Pharmacokinetics of Antiparasitic Agents

About one-sixth of the world's population is affected by a neglected tropical disease as defined by the World Health Organization and Center for Disease Control. Parasitic diseases comprise most of the neglected tropical disease list and they are causing enormous amounts of disability, morbidity, mortality, and healthcare costs worldwide. The burden of disease of the top five parasitic diseases has been estimated to amount to a total 23 million disability-adjusted life-years. Despite the massive health and economic impact, most drugs currently used for the treatment of parasitic diseases have been developed decades ago and insufficient novel drugs are being developed. The current review provides a compilation of the systemic and target-site pharmacokinetics of established antiparasitic drugs. Knowledge of the pharmacokinetic profile of drugs allows for the examination and possibly optimization of existing dosing schemes. Many symptoms of parasitic diseases are caused by parasites residing in different host tissues. Penetration of the antiparasitic drug into these tissues, the target site of infection, is a prerequisite for a successful treatment of the disease. Therefore, for the examination and improvement of established dosing regimens, not only the plasma but also the tissue pharmacokinetics of the drug have to be considered. For the current paper, almost 7000 scientific articles were identified and screened from which 429 were reviewed in detail and 100 were included in this paper. Systemic pharmacokinetics are available for most antiparasitic drugs but in many cases, not for all the relevant patient populations and only for single- or multiple-dose administration. Systemic pharmacokinetic data in patients with organ impairment and target-site pharmacokinetic data for relevant tissues and body fluids are mostly lacking. To improve the treatment of patients with parasitic diseases, research in these areas is urgently needed.

Intra-cystic concentrations of albendazole-sulphoxide in human cystic echinococcosis: a systematic review and analysis of individual patient data

Cystic echinococcosis (CE) is a widespread zoonosis caused by the species complex Echinococcus granulosus. Albendazole (ABZ)-the first-line anthelminthic drug for medical treatment of CE-is metabolized in vivo to the active derivative ABZ-sulphoxide (ABZ-SO). Target-site ABZ-SO concentrations in the hydatid cyst mediate the anthelminthic effect in CE. Primary outcome of this systematic review of individual patient data was the intra-cystic ABZ-SO concentration stratified by cyst size, location, calcification status and use of praziquantel. Studies reporting intra-cystic ABZ-SO concentrations in humans were identified by a systematic search. A pooled analysis of individual patient data was performed to assess intra-cystic concentrations. Pharmacokinetic data of 121 individual cysts were analysed. There was no correlation between plasma and intra-cystic ABZ-SO concentrations (rho = -0.03, p = 0.76). Intra-cystic drug concentrations were also not associated with sex and treatment duration. Use of praziquantel in combination with ABZ was associated with higher plasma (median 540 vs. 240 μg/L; p = 0.04) but not intra-cystic ABZ-SO concentrations (median 220 vs. 199 μg/L; p = 0.36). Relative drug concentrations in hepatic cysts were higher than in other cysts (0.8 vs. 0.4; p = 0.05). Intra-cystic concentrations were higher in calcified than non-calcified cysts (median 897 vs. 245 μg/L; p = 0.03). There was a trend towards higher intra-cystic concentrations in smaller sized cysts (β = -17.2 μg/L/cm; 95th CI, -35.9 to 1.6; p = 0.07). This study demonstrates that mean intra-cystic drug concentrations are similar to plasma concentrations on a population level. However, in individual patients plasma concentrations are not directly predictive for intra-cystic concentrations. The use of booster drugs was not associated with higher intra-cystic ABZ-SO concentrations in this analysis.

Anaphylaxis due to ruptured pulmonary hydatid cyst in a 13-year-old boy

Hydatid cyst, a common disease in the world, is usually transmitted to humans through dog feces. Hydatid cyst is caused by Echinococcus granulosus. Diagnostic interventions for hydatid cyst include physical examination and chest x-ray tomography. Although the treatment options of hydatid cyst vary according to the clinical findings of the patients, the primary treatment may be considered as surgery. We herein reported the case of a child hospitalized due to pneumonia who developed anaphylaxis as a result of the rupture of a pulmonary hydatid cyst.

Long-term outcomes of intraoperative and perioperative albendazole treatment in hepatic hydatidosis: single center experience

PURPOSE

The aim of this study was to evaluate long-term outcome of the intraoperative and perioperative albendazole (ALB) treatment on the recurrence and/or secondary hydatidosis.

METHODS

One hundred and one patients with hepatic hydatidosis were treated intraoperatively and perioperatively with ALB, in addition to surgery. Perioperative ALB treatment was given in a dose of 12-15 mg/kg/day. The ALB treatment was started 13.27 ± 14.34 days before the surgery, and it was continued for 4.39 ± 3.11 months postoperatively. A total of 1.7 µg/mL of ALB solution was used as a protoscolidal agent. The follow-up period was 134.55 ± 51.56 months.

RESULTS

Four patients died, with only one death was secondary to hydatid disease (cerebral eccinococcus). There was only one recurrence (1%) of hepatic hydatidosis. Early and late morbidity rates were 8.91% and 7.92%, respectively.

CONCLUSION

Our results suggest that intraoperative and perioperative ALB is effective for the prevention of hepatic hydatidosis recurrence and/or secondary hydatidosis.

Pregnancy complicated by abdominopelvic hydatid disease

A 22-year-old second gravida presented with asymptomatic abdominal and pelvic hydatid disease at 16 weeks gestation. She opted for conservative management and was treated with oral Albendazole. She underwent elective caesarean along with cyst excision at term as the large pelvic cyst precluded vaginal delivery. A healthy baby girl weighing 2600 g with Apgar of 9, 9 at 1 and 5 min was delivered.

Pleuropulmonary hydatid disease treated with thoracoscopic instillation of hypertonic saline

Hydatid disease is caused by the larval stage of the cestode, Echinococcus granulosus. Man is the intermediate host in its life cycle. The most common organ involved is liver followed by lung. Although surgery remains the definitive treatment for symptomatic lesions, it is associated with considerable morbidity. Other less invasive treatment strategies as an adjunct to medical treatment that have been tried in various case series include percutaneous aspiration, instillation and reaspiration of scolicidal agents (PAIR), and thoracoscopic removal of cysts located subpleurally. Here we report the case of a 58 year old gentleman with hepatic and pleuropulmonary hydatid disease who was subjected to medical thoracoscopy and instillation of hypertonic saline (3%), followed by medical management with albendazole with which complete resolution of the pulmonary cysts was achieved.

Peritoneal perforation of liver hydatid cysts: clinical presentation, predisposing factors, and surgical outcome

The aim of this study was to evaluate the clinical presentation of, predisposing factors in, and early and long-term outcome of patients treated surgically for intraperitoneal ruptured liver hydatid cysts. Medical records of 27 patients with traumatic rupture of hydatid cysts were evaluated retrospectively, as were records of 347 patients with nonperforated hydatid cysts. The ratio of perforation cases to nonperforation cases was 7.8%. Traffic accidents were the most common cause of perforation (n = 16). All patients had abdominal findings, and two patients (7%) had anaphylactic findings. The sensitivities of computed tomography and ultrasonography were 100% and 93%, respectively. Conservative surgical procedures were used for 80.5% of cysts and radical procedures for 19.5%. Associated organ injuries were determined in 10 patients. No significant difference was found between patients with peritoneal perforation and those without perforation in terms of sex (p = 0.403), previous hydatid disease surgery (p = 0.565), localization (p = 0.241), number of cysts (p = 0.537), presence of cystic content infection (p = 0.65), or presence of bile duct communication (p = 0.37). However, there were significant differences in age (p = 0.004), cyst diameter ( > 10 cm) (p = 0.03), and presence of superficially localized cysts (p = 0.011). Three patients developed recurrence. In the group of patients with perforation, the complication and recurrence rates were not statistically different in a comparison of surgical techniques (p = 0.37). No postoperative deaths occurred. The main predisposing factors for cyst perforation are young age and superficial localization. Peritoneal rupture increases the rates of postoperative morbidity and recurrence; in contrast, there was no significant relation between the operative procedure and the morbidity and recurrence rates.

Preoperative albendazole and scolices viability in patients with hepatic echinococcosis

To determine the plasmatic and intracystal concentrations of albendazole sulfoxide (AS) and correlate them with the viability of the scolices in patients surgically treated for hepatic hydatid cysts (HHC) that received albendazole preoperatively, as an indirect way of evaluating the scolicide efficacy of the drug. A non-consecutive series of patients with uncomplicated HHC, underwent operation at the Department of Surgery, Regional Hospital of Temuco, Chile, between 2001 and 2002. The patients were given 10 mg/kg/day of albendazole for 4 days prior to the surgery. Intraoperative samples of venous blood and hydatid fluid were taken, in which the plasmatic concentration (PIC) and intracystal concentration (ICC) of AS were measured by means of high-performance liquid chromatography. With the remaining hydatid fluid, the viability of the scolices was examined. The following variables were taken into consideration: diameter, type of cyst, number of cysts, and development of cyst-biliary communications. Descriptive statistics were used in the calculation of medians, averages, and standard deviations, and analytical statistics were used for the comparison of continuous variables applying the t-test and the Mann-Whitney U-test. A total of 26 patients with HHC, with a median age of 39.5 years (range: 16-80 years); 16 were women (61.5%). Nineteen patients presented only one cyst (73.1%), and the diametric median of the cysts was 14.5 cm (range: 7-30). Fourteen patients presented univesicular cysts (53.9%), and the remaining 12 had multivesicular cysts (46.1%). The average PIC of AS in the whole series was 1.88 +/- 0.5 microg/ml and the ICC was 0.26 +/- 0.2 microg/ml. The ICC in viable hydatid cysts was 0.25 microg/ml versus 0.28 microg/ml in non-viable cysts (p = 0.7556). The absence of association between intracystal levels of AS and the viability of the scolices allows one to posit indirectly that albendazole is ineffective as a scolicidal agent administered preoperatively for 4 days.

HEMATOLOGIC AND PLASMA BIOCHEMICAL CHANGES ASSOCIATED WITH FENBENDAZOLE ADMINISTRATION IN HERMANN'S TORTOISES (TESTUDO HERMANNI)

Toxicosis associated with benzimidazole anthelmintics has been reported with increasing frequency in zoologic collections. Clinical signs, clinicopathologic abnormalities, and gross and histologic lesions are primarily the result of damage to the gastrointestinal and hematopoietic systems. Profound leukopenia, especially granulocytopenia, is the most common and severe clinicopathologic change associated with benzimidazole administration. Death usually occurs from overwhelming systemic bacterial and/or fungal infections secondary to severe immunosuppression. In this 125-day study, six male Hermann's tortoises (Testudo hermanni) were treated orally with two 5-day courses of fenbendazole 2 wk apart at a dosage of 50 mg/kg. Serial blood samples were used to assess hematologic and plasma biochemical changes before, during, and following the treatment period. Although the tortoises remained healthy, blood sampling indicated an extended heteropenia with transient hypoglycemia, hyperuricemia, hyperphosphatemia, and equivocal hyperproteinemia/hyperglobulinemia, which were considered to be in response to fenbendazole administration. Changes in several other clinicopathologic parameters appeared to correlate with fenbendazole administration. The hematologic and biochemical changes seen in the healthy animals in this study should be considered when treating compromised tortoises with fenbendazole. Hematologic and plasma biochemical status of tortoises/reptiles should be determined before treatment and monitored during the treatment period. The risk of mortality of an individual from nematode infection should be assessed relative to the potential for metabolic alteration and secondary septicemia following damage to hematopoietic and gastrointestinal systems by fenbendazole.

Results of alcohol and albendazole injections in hepatic hydatidosis: experimental study

BACKGROUND

Percutaneous drainage with alcohol injection for hydatid cysts has been commonly used in the last two decades. Albendazole is the drug of choice in the medical treatment of hydatidosis, and has also been used as an intraoperative scolicidal solution. The side-effects of its local application are not well known and have not been investigated. The purpose of the present study was to investigate the effects of the intracystic injections of alcohol and albendazole solutions on the hydatid cysts and hepatobiliary system of rabbits.

METHODS

There were three groups of eight rabbits: a control group, an alcohol group and an albendazole group. In all groups hepatic hydatidosis was obtained. The control group received no therapeutic procedure. Cyst liquid was aspirated, and alcohol or albendazole solutions were injected in the other two study groups. alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyl transferase (GGT) levels, echinococcus indirect hemagglutination (IHA) tests, and the size and volume of the residual cysts were investigated. Liver was histopathologically evaluated.

RESULTS

The ALT, AST, GGT, and alkaline phosphatase (ALP) levels were significantly higher in the alcohol group, whereas echinococcus IHA level was highest in the control group than in the study groups. Albendazole had similar effects but of a lesser degree (P < 0.01). After therapy, the cyst volume was greater in the control than in the albendazole group (P < 0.01). In histopathological evaluation hepatocellular necrosis, portal inflammation and fibrosis were most severe in the alcohol group (P < 0.01).

CONCLUSIONS

Alcohol and albendazole solutions are effective as scolicidal solutions. Higher scolicidal effect and lesser side-effects on hepatobiliary system are the advantages of albendazole solution.

Dual treatment of albendazole in hepatic hydatidosis: New therapeutic modality in 52 cases

BACKGROUND

Hepatic hydatidosis still remains as a serious problem in general surgery. Recurrence and/or secondary hydatidosis rates are up to 25% in the cases treated with surgery alone. Albendazole is the most commonly used drug in the medical treatment of echinococcosis. The aim of the present study was to evaluate the effect of albendazole using the intraoperative and perioperative periods as dual therapy.

METHODS

Fifty-two cases of hepatic hydatidosis were evaluated and treated by dual treatment of albendazole together with surgery. Perioperative albendazole treatment was given in a dose of 12-15 mg/kg per day in four divided doses. The treatment started 2-28 days before the surgery when the diagnosis was established and continued for 2-24 months (4.76 +/- 3.25) postoperatively in a cyclic monthly form. A total of 1.7 microg/mL albendazole solution was used as a protoscolicidal agent in the cystic cavity intraoperatively. In the postoperative period serology, ultrasonography and computed tomography evaluations were done. The follow-up period was 5-92 months (mean: 62.48 months).

RESULTS

There was no recurrence in the present study. One patient died in the 6th postoperative week due to cerebral hydatidosis and multiple organ failure. Early and late morbidity rates were 7.69 and 9.61%, respectively.

CONCLUSIONS

Dual albendazole treatment is effective in the prevention of recurrences and/or secondary hydatidosis.

Liver hydatid disease: Morphological changes of protoscoleces after albendazole therapy

Background. Postoperative recurrence of the liver hydatid disease befalls approximately 10?30% of patients. Preoperative or postoperative therapy with albendazole in single therapeutic protocol (800 mg/d, within 28 days) indicated the need to evaluate the hydatid cyst liquid protoscoleces viability. Morphological changes of protoscoleces following the treatment with drugs are not well known. Aim. To estimate the viability of protoscoleces after preoperative or postoperative albendazole therapy, and their ability for cystic metamorphosis. Methods. A prospective, randomized clinical trial included 30 patients with liver hydatid disease, treated with albendazole and surgically (I group), and 30 patients in the control group treated only surgically (II group). The concentration of albendazole and its active metabolite albendazole sulphoxide in the cysts contents were determined using HPLC. Estimation of protoscoleces viability was based on the established micromorphologic criteria, and compared between the patients treated with albendazole, and the patients treated only surgically. Biological assessment of the viability was performed on protoscoleces with uncertain signs of the disturbed viability (unchanged structure, evaginated, without movements) using intraperitoneal injection of 1 ml of protoscoleces prepared suspension to AO type of rats. Results. The concentration of albendazole in cysts' contents ranged from 0 to 64.9 ?g/ml, and of its active metabolite from 0.5 to 40.8 ?g/ml. The presence of fully viabile protoscoleces in the albendazol treated patients was significantly lower than in the control group. A significant difference was noticed in the presence of disintegrated protoscoleces without movements in the albendazol treated group, compared to the control group. Biological assessment of the viability showed incapability of these protoscoleces for cystic metamorphoses. Conclusion. Low viability of parasites due to medicamentous therapy is very useful and important to surgeons, because the fertility of cysts is lower, and the risk of the disease recurrence is reduced.

Treatment of uncomplicated hydatid cyst of the liver by closed marsupialization and fibrin glue obliteration

Treatment of hepatic echinococcosis remains a surgical problem not only in endemic countries. Between January 1983 and December 1999 a total of 29 patients underwent surgical treatment for hepatic hydatidosis at the Department of General Surgery at the University Hospital of Granada. The diagnosis was based on clinical criteria, serology, and imaging techniques. There were 16 male and 12 female patients (ages 7-67 and 30-74 years, respectively). Concomitant extrahepatic complications were found in seven patients. Among them, five had secondary parasitic cysts in the peritoneal cavity. In one case an intrathoracic rupture was found, and one patient suffered an intraabdominal rupture with anaphylactic shock. The right lobe was affected in 62% (18 patients). Hepatic cysts were multiple in 4 cases and calcified in 13. Conservative surgical procedures were performed in 23 patients (closed marsupialization with fibrin glue obliteration in 17 and drainage-marsupialization in 6), and radical surgical procedures were undertaken in 6 (pericystectomy in 5 and hemihepatectomy in 1). One patient underwent an explorative laparotomy with intraabdominal lavage followed by pericystectomy after primary resuscitation due to anaphylactic shock. The mean period of hospitalization was 15.9 days, and there were no serious postoperative complications or fatal outcomes. The perioperative morbidity rate was 2.5%. One patient suffered a recurrence of the disease following drainage marsupialization after an interval of 5 years. Our results indicate that the closed marsupialization technique is a safe, sparing method for treating uncomplicated hepatic hydatidosis. The results were also compared to those of a former study reported by our group in which the experience of another 19 years was presented.

Hydatid disease of the urinary tract: review of the management of 9 cases

The aim of this study is to review 9 cases with urinary tract hydatid disease in terms of symptoms, findings, laboratory tests, radiological findings and treatment modalities. There were 7 males and 2 females with a mean age of 33.6 years (range from 7 to 67 years). In 6 patients hydatid cyst was located in the kidney (1 involved the liver), in 2 the cysts were in the paravesical and retrovesical region (1 coexisted bladder tumor) and 1 the cyst was located adrenal gland. The investigations included urinalysis, eosinophil count, Casoni skin test, indirect haemagglutination test (IHA), transabdominal ultrasonography (TAUS), intravenous urography (IVU) and computed tomography (CT). All patients underwent various surgical procedures and were followed-up for an average of 3 years (range: 1 month to 5 years) period in terms of complications and recurrence rates. The most common symptom was lumbar or abdominal pain. Eosinophilia was seen in 4 patients (44.4%), IHA positivity in 3 patients (33.3%) and Casoni skin test were positive in 3 patients (33.3%). The most diagnostic method of radiological investigations was abdominal pelvic CT (100%). After surgical treatment, in mean a 3 year (range: 1 month to 5 years) follow-up period, no complication and recurrence were seen. Hydatid disease of the urinary tract is relatively uncommon and is likely to cause considerable diagnostic difficulties for clinicians and radiologists: therefore, it should be born in mind in the differential diagnosis of space-occupying lesions of the urinary tract.

Hydatid lung disease (echinococcosis/hydatidosis)

Two Echinococcus species may exhibit medical relevance as causative agents of pulmonary forms of echinococcosis. Most importantly, infections with Echinococcus granulosus result in "cystic hydatid disease" or "cystic echinococcosis," which affects the lungs in a considerable ratio of cases. Echinococcus multilocularis, which causes "alveolar echinococcosis," affects the lungs relatively rarely and then usually upon metastasizing from primary hepatic lesions. Cystic echinococcus and alveolar echinococcus differ pathologically and clinically so greatly that they are considered separately in this article, although alveolar echinococcus is covered minimally because of its minor importance regarding lung infections.

In vitro and in vivo suppression of growth of hepatocellular carcinoma cells by albendazole

Tubulin protein is a major target of drug molecules, and consequently, tubulin inhibitors have attracted great attention as antimitotic antitumor agents for chemotherapeutic use. It has been shown that, the benzimidazole carbamate group of antiparasitics including albendazole act by inhibiting tubulin polymerization. In this study, albendazole was tested in culture against a range of human, rat and mice hepatocellular carcinoma (HCC) cells and in vivo against human SKHEP-1 tumor growth in nude mice. Albendazole induced a dose-dependent inhibition of [(3)H]thymidine incorporation in all cell lines examined and a dramatic decline in cell numbers in SKHEP-1 cells. The inhibitory effect of albendazole was evident at the 100 nM concentration and at 1000 nM, proliferation in all cell lines examined was inhibited by more than 80%, while, proliferation of HepG2, Hep3B and SKHEP-1 were suppressed by more than 90%, compared to control. Cell cycle analysis revealed that, depending on the dose employed, albendazole can arrest SKHEP-1 cells at both G0-G1 (250 nM) and G2-M (1000 nM) phases of the cycle. Albendazole treatment (300 mg/kg per day oral for 20 days) of nude mice inoculated subcutaneously with SKHEP-1, led to profound suppression of tumor growth. Immunohistochemical analysis of these tumors revealed that compared to control, those treated with albendazole have lower growth fractions. These findings demonstrate that albendazole strongly suppresses both in vitro and in vivo proliferation of HCC cells.

Effect of albendazole sulfoxide solution on the scolices and the hepatobiliary system

The use of scolocidal solutions in the hepatobiliary system may result in caustic sclerosing cholangitis. In this study, the effectivenes of a biological metabolite of albendazole, albendazole sulfoxide, on scolices and the hepatobiliary system was evaluated. In the in vitro study, it was found that 100 microg/ml albendazole sulfoxide solution had strong scolocidal effect in 15 min. In the in vivo study, two experimental groups, each consisting of 8 rabbits aged 3-4 months and weighing 2,500 +/- 250 g, 100 microg/ml albendazole sulfoxide and normal saline were given into the biliary tract. ALP, GGT, SGOT and SGPT values on days 7, 30 and 60 were not found to be significantly increased compared to preoperative values. Total bilirubin values were high in the working group 7 and 30 days postoperatively and on day 30 in the control group, returning back to normal levels on day 60 in both groups. Histopathological evaluation of the liver parenchyma and the biliary system on day 60 revealed no differences between the groups. Consequently, albendazole sulfoxide solution may be used intraoperatively for scolocidal purposes.

Cystic echinococcosis in a Jordanian patient: albendazole in a short-term immigrant

With an ever increasing number of international travelers, physicians should be aware of the diseases that have rarely been encountered in their home countries. Cystic echinococcosis (CE) caused by Echinococcus granulosus is seldom seen in Japan despite frequent occurrence of the other type of echinococcosis, alveolar echinococcosis (AE) caused by E. multilocularis, in its northern parts. However, CE is prevalent in many parts of the world including the United Kingdom, Mediterranean basin, Middle East, South America, and Australia, and is supposed to be resurgent in several parts of the world. The disease is acquired by the oral ingestion of the eggs of E. granulosus passed into the feces of several definitive host animals carrying tapeworms, mostly dogs. These definitive hosts are infected by cannibalizing intermediate host animals including sheep and cattle whose livers and/or lungs are affected by cystic lesions that contain protoscoleces. In endemic areas the diagnosis of CE is not considered to be complicated; typical morphological features composed of cysts as revealed by ultrasonography and/or computerized tomography (CT) scan. The diagnosis is also aided by serological methods detecting serum antibodies. However, imaging procedures show a variety of features that could often lead to misdiagnosis as other diseases. Moreover, serological assays are sometimes difficult to interpret because of their incomplete sensitivities and specificities. Hence, a comprehensive understanding of a spectrum of imaging features and the application of serological methods with better sensitivities and specificities are indispensable. The mainstay of treatment of the disease is still surgical removal of cysts that has the potential to lead to a complete cure. Recently, the less invasive method PAIR (Puncture of cysts percutaneously, Aspiration of fluid, Introduction of protoscolicidal agent, and Reaspiration) was introduced with considerable success, and could be a promising alternative to surgery. Lastly, medical treatment with oral mebendazole or albendazole, especially the latter, can be beneficial not only as a adjunctive to surgery or PAIR, but as a sole treatment in cases in which invasive methods are not indicated. Here we report a Jordanian patient with CE whose diagnosis was substantiated by a novel immunoblot assay and who showed a rapid improvement during albendazole therapy.

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.

Alveolar hydatid disease. Review of the surgical experience in 42 cases of active disease among Alaskan Eskimos

OBJECTIVE

The authors reviewed the pathophysiology and clinical management of endemic alveolar hydatid disease in Alaskan Eskimos, incorporating recent developments in diagnosis and treatment.

SUMMARY BACKGROUND DATA

Alveolar hydatid disease is a highly lethal zoonotic infection caused by the larval stage of Echinococcus multilocularis. This cestode is restricted geographically to northern climates, where foxes and small rodents represent the natural hosts. Domestic dogs also may serve as definitive hosts, and thus, transmit the parasite to humans. Human infection is characterized by the development of a cancer-like hepatic mass, which may extend to adjacent structures or metastasize to distant sites. If the infection goes untreated, mortality reaches 80%.

METHODS

The medical records of all patients with alveolar hydatid disease diagnosed or treated at the Alaska Native Medical Center between 1951 and 1993 were reviewed. Forty-two cases of active disease are presented.

RESULTS

Nine patients underwent resection of hepatic lesions with intent to cure, and each had a favorable result. Average post-diagnosis survival of those patients was 22 years; six still are living and free of disease. Partial resections or drainage procedures were performed in ten patients. Chemotherapy was used to augment the surgical treatment of eight patients, and four received chemotherapy alone, resulting in improved outcomes compared with historic controls. Late complications included hepatic abscess, biliary obstruction, and portal venous hypertension.

CONCLUSIONS

Whereas alveolar hydatid disease rarely is encountered in other areas of North America, the biologic potential for spread of the disease may be increasing because of illegal importation of infected foxes to the Eastern seaboard. Therefore, the surgical community should maintain an awareness of the diagnosis and management of this potentially devastating parasitic infection.

Primary pelvic hydatid cyst presenting with obstructive uropathy and renal failure

Primary pelvic hydatid cyst is a rare entity. Pelvic hydatid cysts usually present with pressure symptoms involving adjacent organs (bladder and rectum usually). A case of primary pelvic hydatid cyst presenting with obstructive uropathy leading to chronic renal failure is presented. A combination of preoperative albendazole therapy of 1.2 g/day for 8-12 weeks and surgical excision were effective in alleviating the symptoms and improving the renal function.

Diagnostic evaluation and surgical management of hydatid disease of the liver

Human echinococcosis is still endemic in some areas of the world, including Mediterranean countries. Because there is no effective medical therapy, surgery remains the principal mode of treatment. A consecutive of 132 patients operated on for liver hydatid disease between January 1977 and February 1993 were analyzed. There were 60 men (45.4%) and 72 women (54.6%) aged 31 to 88 years (mean 56 years). The right lobe of the liver was affected in 68 cases (51.5%), the left lobe in 31 cases (23.5%), and both lobes in 14 cases (10.6%); there were multiple liver cysts in 7 cases (5.3%), concomitant cysts in other parenchymal organs in 4 cases (3.0%), and disseminated intraabdominal hydatid disease in 8 cases (6.1%). Clinical symptomatology consisted of abdominal pain, fever, jaundice, urticaria, and an abdominal mass. Preoperative diagnosis was established using imaging studies: plain abdominal films, ultrasonography, computed tomography, and serologic tests. Three patients (2.3%) underwent simple closure without drainage, 7 patients (5.3%) cyst excision, 4 patients (3.0%) marsupialization, 1 patient (0.8%) left lateral segmentectomy, 15 patients (11.3%) external drainage, 69 patients (52.3%) omentoplasty, and 33 patients (25.0%) combinations of procedures. Postoperative morbidity was low and consisted of hepatic abscess development, wound infection, bowel obstruction, and biliary leaks. Six patients (4.5%) had recurrent disease. One patient died during the postoperative period because of septic complications. Among the surgical techniques we used, excision of the cyst (when feasible) and omentoplasty produced the lowest complication rates and the best clinical results.

Albendazole chemotherapy for human cystic and alveolar echinococcosis in north-western China

Human echinococcosis is highly endemic in north-western China; the main treatment is by surgery. In this paper, we report the results of chemotherapy with albendazole (ABZ), 15-20 mg/kg/d orally, for 30 d with intervals of 10 d between treatments for 3-6 courses. For multi-organ cystic echinococcosis (CE) and alveolar echinococcosis (AE), patients were given 12-18 courses of ABZ. Patients were divided into 4 groups: (i) ABZ surgery group, albendazole with surgery for 21 CE cases: (ii) non-ABZ surgery group, 80 CE cases treated by surgery alone; (iii) ABZ CE group, albendazole treatment alone in 58 CE cases, and (iv) ABZ AE group, 14 AE patients treated by albendazole and surgical intervention and 5 AE patients treated by albendazole alone. Twenty-seven of 34 (79.4%) cysts in group (i) patients showed increased necrotic changes and decreased viability of the cysts compared to group (ii). However, 10 of 84 (11.9%) cysts in group (ii) patients showed spontaneous evidence of necrosis at surgery. In group (iii), ABZ treatment alone was successful in 14 (24.1%), resulted in improvement in 29 (50%) and had no effect in 15 (25.9%) patients. Seven cases in group (iv) improved, with diminished size of lesions which were non-viable. The remaining 7 cases in group (iv) showed evidence of cyst viability at surgery; 2 could not be saved after a further 15 courses of albendazole. Of the five AE patients in group (iv) who received only ABZ, one improved, 2 stabilized, one deteriorated and one died. Albendazole chemotherapy, while not completely effective, has an important role in treatment of both cystic and alveolar echinococcosis.

Therapy of human hydatid disease with mebendazole and albendazole

We report our experience in the treatment with benzoimidazole carbamates (mebendazole and albendazole) of 337 patients affected by hydatid cysts with different localizations. The treated cysts showed degenerative modifications in 50.6% of the cases after mebendazole treatment and in about 80% after albendazole treatment. Relapses after therapy were observed in 30% of the cases; about 95% of the recurring cysts showed good susceptibility to a further cycle of therapy with benzoimidazole carbamates. Side effects observed with either drug were not severe and always reversible, consisting mainly of abdominal pains and increased levels of transaminases in serum. Among the factors that may influence the therapeutic results are the drug employed, the age of the cysts, the age of the patient, and the localization of the cysts and their morphological characteristics. Moreover, it can be hypothesized that each hydatid cyst has an intrinsic sensitivity to benzoimidazole carbamates.

Albendazole in the treatment of pulmonary echinococcosis

Ten patients with pulmonary hydatid disease diagnosed on the basis of a chest radiograph and a positive response to the indirect haemagglutination test for hydatid disease were treated with albendazole 10 mg/kg/day for eight weeks. None of the 10 patients showed any radiological or serological improvement with this treatment regimen. Albendazole in these doses appears to have little role in the treatment of pulmonary hydatid disease.

CT findings and surgical treatment of double intracranial echinococcal cysts

The authors present a young male patient with two intracranial lesions, one in the left occipital lobe, the other in the left temporal lobe. These masses were totally removed and both proved to be alveolar hydatid cysts. Surgery for a large hepatic mass, diagnosed after the first craniotomy, was refused by the patient.

Percutaneous treatment of hydatid cysts (Echinococcus granulosus)

A new method called PAIR (Puncture-Aspiration of cyst contents--Injection of hypertonic saline solution--Reaspiration) was used as a percutaneous treatment of hydatid cysts. In 37 patients, 120 cysts were punctured. All patients had not been considered surgical candidates. The cysts were localized in the liver, peritoneum, spleen, kidneys, muscles, and bones. In 70% of patients, good results were obtained. Recurrence occurred in 5 of 120 cysts, all at the beginning of our experience when a low concentration of sodium chloride solution was injected. Moderate allergic reactions occurred during seven cyst aspirations. No anaphylactic shock, sudden deaths or dissemination of cyst contents were observed.

Comparison of Albendazole and Praziquantel therapy of Echinococcus granulosus in naturally infected sheep

The effects of albendazole (10 mg kg-1 day-1) and praziquantel (50 mg kg-1 day-1) for 6 weeks on naturally infected sheep with pulmonary cysts of Echinococcus granulosus of proven viability were studied. Immediately following therapy, one of three sheep treated with praziquantel had viable cysts and 7 months later one of two sheep had viable cysts. One sheep died during albendazole therapy, but 7 months following therapy only one of five sheep had viable cysts. Electron microscopy demonstrated necrotic germinal layer tissue in most albendazole-treated cysts and praziquantel also had an effect on cyst ultrastructure. These data suggest that recurrence in humans treated with albendazole may be small. Whilst praziquantel was not particularly effective in this animal model, its clear effect on the ultrastructure suggests that an increased dose and combination therapy with albendazole may be more effective.

Chemotherapy of experimental Echinococcus multilocularis in jirds

A total of 50 jirds (Meriones unguiculatus) were infected by intraperitoneal implantation of 0.20 g metacestode tissue of Echinococcus multilocularis. The feed of 4 groups of 10 animals each was treated for 35 days with 500 ppm albendazole, flubendazole, mebendazole or praziquantel; 1 group of 10 jirds served as unmedicated controls. At autopsy 2 weeks after the end of medication, the transplants had increased in size and weight, reaching a total weight of 78.11 g in the control group, 21.60 g in the albendazole-treated group, 3.63 g in the flubendazole-treated group, 7.00 g in the mebendazole-treated group and 68.91 g in the praziquantel-treated group. The percentage in reduction of parasitic tissue weight as compared with control values was 72%, 95%, 91% and 12%, respectively. The calculated daily drug intake was approximately 48 mg/kg body weight. Drug-related side effects were not observed.

Albendazole treatment of recurrent hydatid disease: serial evaluation with ultrasound

Four patients with complex abdominal hydatid cysts, one of whom also had pulmonary and pelvic involvement, were treated with up to six 28-day courses of albendazole 400 mg per oral twice daily. As part of a prospective study, serial ultrasound scanning was performed after each 28-day course of albendazole and showed evidence of remission of disease in all four patients. Transient minor abnormalities of liver function were noted during treatment. Ultrasound scanning showed the disappearance of daughter cysts and cystic septation, increase in echogenicity and marked reduction in cyst size. Consolidation of these changes and, in some cases, disappearance of the cysts, were noted with continued therapy. Albendazole seems to be a safe and effective agent in the treatment of recurrent hydatid disease, exerting most of its cysticidal activity within the first 2-3 months of therapy.

Pre-operative albendazole therapy for recurrent hydatid disease

Two patients with recurrent hydatid disease had a 1-month course of albendazole before surgery. In one case with a thick-walled host capsule, the scolicidal effect was incomplete, but, in the second case, in which thin-walled cysts were present, albendazole entered the cyst and was completely effective as a scolicidal agent. For thick-walled cysts, it may be necessary to use albendazole for more than 1 month pre-operatively in order to achieve a scolicidal effect.

Neurocysticercosis: treatment with albendazole and dextrochloropheniramine

We evaluated the use of albendazole in combination with dextrochloropheniramine for the treatment of neurocysticercosis. Forty patients were treated from September 1984 to December 1987; each was diagnosed on the basis of clinical, epidemiological, cerebrospinal fluid and tomographic data. Patients were divided into 3 groups according to the albendazole treatment schedule. Group I received 10-15 mg/kg albendazole daily; group II received 15-25 mg/kg/d; group III received 15-30 mg/kg/d. Each patient also received simultaneously 18 mg/d of dextrochloropheniramine. Clinical improvement was observed in 4 patients in group I (50.0%), 10 patients in group II (83.3%) and 18 patients in group III (94.7%). Three patients in group II, and one in group III, died. Group III patients showed a significant improvement in quality of life compared to the other 2 groups. Side effects were insignificant in all groups. The combination of albendazole and dextrochloropheniramine seems to be a promising treatment for neurocysticercosis, especially at the doses used for group III, i.e. 15 mg/kg/d of albendazole for 21 d followed by 20-30 mg/kg/d for 30 d after a one-week interval, in combination with 18 mg/d of dextrochloropheniramine.

Diagnosis of cystic hydatid disease: role of aspiration cytology

Fine needle aspiration of mass lesions is reported in eleven patients in whom cystic hydatid disease (CHD) was not a differential diagnosis or whose serological results were negative. Aspiration was continued until no more fluid could be obtained. In five patients aspiration was done under ultrasound guidance. No sequelae were observed that could be attributed to aspiration per se. Aspirated fluid was stained with haematoxylin and eosin and giemsa or was passed through 5 micron polycarbonate filters which were then stained in the same way. The aspirated material and polycarbonate filters were also stained with trichrome which proved the best stain to demonstrate the acid-fast hooklets. Such filtration of the total volume of the aspirated material or that evacuated at operation is simple, quick, and accurate.

Echinococcus multilocularis: in vivo results of therapy with albendazole and praziquantel

The effects of albendazole and praziquantel on the growth of Echinococcus multilocularis were studied in cotton rats. Albendazole (20 and 50 mg/kg) reduced parasite weight and increased the length of survival of infected animals but viable infection was present after treatment. In an in vitro system albendazole sulphoxide entered cysts of E. multilocularis passively. Praziquantel 100 mg/kg was ineffective but 500 mg/kg significantly inhibited growth. A combination of albendazole and praziquantel was no more effective than either agent alone.

Albendazole treatment of human cystic echinococcosis

The effect of albendazole was investigated in 20 patients with single or multiorgan hydatid cyst disease. Albendazole was used at a dose of 10 mg/kg daily in cycles of 28 d for four cycles with 15 d between cycles. Follow-up ranged from 12-18 months. Response varied according to the organ involved, the most successful results being with liver and peritoneal cysts. A positive response was seen in 47% of 34 cyst sites and a partial response was seen in a further 38% of sites. Overall response was classed as completely successful in 30% of patients, and partially successful in 60% at the end of follow-up. Adverse events were rare, although occasional abnormalities of liver function were seen.

Combination chemotherapy of Echinococcus granulosus--in vitro studies

Both benzimidazole carbamates and isoquinoline compounds have activity against protoscoleces of Echinococcus granulosus in culture in vitro; combinations of albendazole sulphoxide and praziquantel are more effective than either agent alone.

Albendazole treatment of multiple cerebral hydatid cysts: case report

A patient with primary multiple cerebral hydatid cysts was treated with albendazole. The daily dose was 10 mg/kg, taken 3 times a day with main meals, in 4 one-month courses separated by intervals of 15 days. Computerized tomography did not reveal any cerebral cysts at the end of therapy; complete calcification was observed at the sites of previous cysts 12 months later. Albendazole was very well tolerated. The results of therapy suggest that albendazole is a valuable contribution to the treatment of cerebral hydatid cysts.

Determination of minimum effective concentration of praziquantel in in vitro cultures of protoscoleces of Echinococcus granulosus

The minimum effective concentration of praziquantel against protoscoleces of Echinococcus granulosus (ovine strain) was determined in vitro; 20 micrograms/litre gave statistically significant results. No difference was seen between the sensitivity of ovine and equine protoscoleces at 50 micrograms/litre. Morphological observations on treated protocsoleces and passage into gerbils both suggested that the eosin-exclusion technique overestimates viability. Electron microscopy of treated protoscoleces showed severe, disruptive tegumentary damage. Praziquantel is thus an extremely active protoscolicidal agent that may have an important peri-operative role in preventing recurrence.

Effect of albendazole sulphoxide on viability of hydatid protoscoleces in vitro

Hydatid protoscoleces obtained from sheep (infected with Echinococcus granulosus) were treated in culture medium with albendazole sulphoxide at final concentrations of 100, 500 and 1000 micrograms/l and the viability was assessed at regular intervals. Over a period of up to 31 days concentrations of 500 and 1000 micrograms/l of sulphoxide significantly reduced the viability in treated groups, as compared with appropriate controls, whilst 100 micrograms/l of sulphoxide had no effect.

Can albendazole reduce the risk of implantation of spilled protoscoleces? An animal study

Post-operative recurrence of hydatid disease occurs in approximately 10% of patients. The role of pre- or post-spillage chemotherapy with albendazole (10 mg/kg) was investigated in a gerbil model. All animals received approximately 5000 protoscoleces of ovine Echinococcus granulosus by intraperitoneal injection. Pre-spillage albendazole therapy did not protect against the development of cysts whilst a significant reduction in numbers of peritoneal cysts was seen in gerbils treated with albendazole 10 mg/kg for one week after inoculation. Two weeks therapy was no more effective. A very short course of albendazole treatment immediately following intraperitoneal 'spillage' of protoscoleces in a gerbil significantly reduced the number of cysts which developed. This finding may well be of clinical value.