Percutaneous evacuation (PEVAC) of multivesicular echinococcal cysts with or without cystobiliary fistulas which contain non-drainable material: first results of a modified PAIR method

Percutaneous treatment of liver hydatid cysts: to PAIR or not to PAIR

PURPOSE OF REVIEW

The aim is to review recent literature for percutaneous treatment of liver hydatid cysts (cystic echinococcosis: CE) via different techniques such as PAIR (puncture, aspiration, injection, and reaspiration), standard catheterization, and modified catheterization technique (MoCaT).

RECENT FINDINGS

PAIR is an established technique and considered to be safe and effective for CE1 and CE3a as it is associated with lower morbidity, mortality, recurrence, and shorter hospital stay as compared with surgery. Standard catheterization is also dedicated for the treatment of CE1 and CE3a. PAIR should be preferred for treatment of liver CE1 and CE3a cysts, since PAIR is associated with lower major complication rates and shorter hospital stay. However, standard catheterization technique is indicated when cysto-biliary fistula develops or any technical difficulty arises during the PAIR. In these cases it is needed to switch PAIR to standard catheterization to complete the procedure.

SUMMARY

For CE1 and CE3a cysts, PAIR and standard catheterization are the choice for percutaneous treatments, while MoCaT is a treatment option for CE2 and CE3b cysts.

Pitsilka M, Magouliotis D, Zacharoulis D. New Energy Devices in the Treatment of Cystic Echinococcosis

Treatment of cystic echinococcosis of the liver still remains a debatable subject. The method of choice should aim for the total elimination of the parasite with minimum morbidity and mortality. Different approaches have been proposed. Medical treatment as a monotherapy has been abandoned due to the high chances of recurrence and is mostly used as an adjuvant to surgery or minimally invasive methods. Surgical methods are divided into conservative ones, which include cystectomy and partial pericystectomy, and radical ones, total pericystectomy and hepatectomy. Radical procedures are correlated with lower complication and recurrence rates and, therefore, should be attempted when indications are present. On the other hand, conservative surgery can be the first option in endemic areas, performed by non-specialized general surgeons. The development of laparoscopic techniques made their use a possible alternative approach in selected cases. The use of percutaneous treatments is also quite widespread due to their minimally invasive nature. New energy devices seem to play a significant role in the treatment of cystic echinococcosis, although more studies are needed to establish their efficacy. Observation without intervention is an option for inactive uncomplicated cysts.

Benign liver lesions 2022: Guideline for clinical practice of Associazione Italiana Studio del Fegato (AISF), Società Italiana di Radiologia Medica e Interventistica (SIRM), Società Italiana di Chirurgia (SIC), Società Italiana di Ultrasonologia in Medicina e Biologia (SIUMB), Associazione Italiana di Chirurgia Epatobilio-Pancreatica (AICEP), Società Italiana Trapianti d'Organo (SITO), Società Italiana di Anatomia Patologica e Citologia Diagnostica (SIAPEC-IAP) - Part I - Cystic lesions

Benign liver lesions are increasingly diagnosed in daily clinical practice due to the growing use of imaging techniques for the study of the abdomen in patients who have non-specific symptoms and do not have an increased risk of hepatic malignancy. They include simple or parasitic cysts and solid benign tumors which differ widely in terms of prevalence, clinical relevance, symptoms and natural history and often lead to significant clinical problems relating to diagnosis and clinical management. Following the need to have updated guidelines on the management of benign focal liver lesions, the Scientific Societies mainly involved in their management have promoted the drafting of a new dedicated document. This document was drawn up according to the present Italian rules and methodologies necessary to produce clinical, diagnostic, and therapeutic guidelines based on evidence. Here we present the first part of the guideline, concerning the characterization of focal hepatic lesions detected by ultrasound, and the diagnosis and clinical management of simple and parasitic hepatic cysts, and of polycystic liver disease.

Treatment of Gharbi Type III Hepatic Hydatid Cysts: A Clinical Dilemma

This article aims to compare available treatment options for type III liver hydatid cysts, including surgery and percutaneous techniques. Hydatid disease is a helminthic infection caused by Echinococcus granulosus and is a serious public health problem in endemic regions of the world. Hydatid cyst of the liver is the most common clinical presentation of Echinococcus granulosus. According to Gharbi classification, hydatid cysts of the liver are classified into 5 types. Type III hydatid cysts are those with fluid collection and septa. Treatment of Gharbi type III hydatid cysts is still controversial. Some researchers think that Gharbi type III hydatid cysts are not suitable for percutaneous drainage, and surgery is the suitable treatment option. There are not enough prospective studies comparing percutaneous and surgical techniques for the treatment of type III hydatid disease of the liver. A proper meta-analysis does not seem to be possible with the available studies in current medical literature.

Management of cystic echinococcosis in the last two decades: what have we learned?

Background

Management options for cystic echinococcosis (CE) remain a serious problem. The main aim of this study was to examine the selection and complications of treatment applied in patients with CE. The second aim was to evaluate the mortality rate and causative factors.

Methods

A retrospective descriptive study of patients diagnosed with CE between 1998 and 2015 was conducted, according to ICD-9 (code 122·0 to 122·9) criteria in the Complejo Asistencial Universitario of Salamanca, Spain.

Results

Four-hundred-ninety-one (491) patients were diagnosed with CE disease and the treatment applied in these patients were: 166 (33.8%) patients received only surgery, 176 (35.8%) surgery and drugs, 17 (3.5%) drugs alone, in 131 (26.7%) patients the strategy was 'watch and wait', and only one patient (0.2%) was applied puncture-aspiration-injection-respiration (PAIR). Thus, a total of 342 patients received surgery, either alone (166) or combined with drugs (176), and a total of 193 (39.4%) patients were medically treated, either alone (17) or combined with surgery (176); 123 (63.7%) patients used albendazole alone; and 70 (36.3%) patients used a combination of albendazole and praziquantel. Sixty-five patients (19.0%) had complications after surgery and seven of them (2%) died. Only 15 (7.8%) cases had side effects from anthelmintics. Throughout the study period, 80 (16.3%) patients died, 14 (2.9%) of them due to CE disease.

Conclusions

Complications of CE are one of the most common causes of mortality in CE patients, with size, location, and number of cysts, and the 'watch and wait' treatment strategy being the main factors associated with mortality.

A systematic review and meta-analysis on the treatment of liver hydatid cyst using meta-MUMS tool: comparing PAIR and laparoscopic procedures

INTRODUCTION

There is an academic debate over surgical treatments of liver hydatid cyst disease. In this study, a systematic review and meta-analysis were carried out in order to evaluate the pros and cons of both PAIR (Puncture, Aspiration, Injection, Respiration) and laparoscopic techniques by considering the outcomes of liver hydatid cysts.

MATERIAL AND METHODS

We designed descriptive Boolean queries to search two databases, PubMed and Scopus, to derive the articles published in the period of January 2000 to December 2016 in order to evaluate the outcomes of these research articles. The outcomes of laparoscopic and PAIR procedures include the rates of cure, postoperative complications, recurrences, and mortality, which were extracted, assessed, and used as their corresponding effect sizes.

RESULTS

Fifty-seven studies including a total of 2832 patients (PAIR group n = 1650 and laparoscopic group = 1182) were analyzed. In this meta-analysis study, a random effect model of correlations of outcomes (postoperative complications, mortalities, recurrences, and cure rates) of PAIR and laparoscopy procedures was used. The meta-analysis and the forest plots of the two procedures show that the PAIR approach is superior in terms of cure, complication, and mortality rates compared with the laparoscopy technique. However, the recurrence rate is low in laparoscopic approaches. Moreover, Egger's tests for determining publication bias and heterogeneity tests were also performed.

CONCLUSIONS

This study shows promising trends toward an advantage of PAIR procedures in treatment of liver hydatid cyst in comparison with laparoscopic procedures. The PAIR procedure is superior to laparoscopy due to having a higher cure rate and lower complication and mortality rates; however, the latter has a lower recurrence rate.

Modern trends in surgical treatment of liver echinococcosis

The article presents literature review about surgical treatment of liver hydatidosis. Particular attention is paid to the development of percutaneous treatment. Also modern trend of surgical treatment are described. We presented results of percutaneous treatment of liver hydatidosis in our clinic. We analized them and made the conclusion that percutaneous treatment is effective and safe method for liver hydatidosis. To reduce the risk of recurrence we have to do it right and all patients must take anti-relapse chemotherapy.

Repeated Percutaneous Treatment of Massive Hepatic Cystic Echinococcosis in a Child

Because of mostly asymptomatic cyst growth and often-neglected nonspecific low-grade symptoms, many cases of cystic echinococcosis (CE) caused by Echinococcus granulosus in the pediatric population are diagnosed at school age, in an advanced and even complicated stage. In 2003, after 5 months of intermittent dull upper-right abdominal pain and nausea, a 13-year-old boy was diagnosed with massive liver CE, with ∼20 round-shaped double-walled medium-sized infective cysts, which permeated the whole liver. Because of their wide distribution across the liver tissue and the risky superficial position of some cysts, liver transplantation emerged as the optimal therapeutic option. Despite being described as only an exceptionally used method for CE, we subjected our patient on 4 occasions to a radiofrequency energy thermoablation (RFT) procedure similar to the one used for malignant neoplasms. In total, 9 superficially situated cysts were initially treated with RFT by using a 14-gauge outer needle and a temperature of 70°C for 8 minutes per cyst, and the remaining cysts were treated with the puncture-aspiration-instillation-reaspiration procedure, along with albendazole (15 mg/kg per day) therapy, for a period of 20 months. After 2 years of follow-up, 4 residual small-sized semisolidified cysts were seen in the liver, and the patient showed no signs of relapse. Although not routinely used, RFT, along with puncture-aspiration-instillation-reaspiration and prolonged albendazole therapy, has shown good tolerability and long-term efficacy in the treatment of multiple infective CE, which could suggest the usefulness of the RFT method beyond salvage situations in pediatric patients.

Ultrasound and Cystic Echinococcosis

The introduction of imaging techniques in clinical practice 40 years ago changed the clinical management of many diseases, including cystic echinococcosis (CE). For the first time cysts were clearly seen before surgery. Among the available imaging techniques, ultrasound (US) has unique properties that can be used to study and manage cystic echinococcosis. It is harmless, can image almost all organs and systems, can be repeated as often as required, is portable, requires no patient preparation, is relatively inexpensive and guides diagnosis, treatment and follow-up without radiation exposure and harm to the patient. US is the only imaging technique which can be used in field settings to assess CE prevalence because it can be run even on solar power or a small generator in remote field locations. Thanks to US classifications, the concept of stage-specific treatments was introduced and because US is repeatable, the scientific community has gained a clearer understanding of the natural history of the disease. This paper reviews the scope of US in CE, describes its strengths and weaknesses compared to other imaging techniques and its relationship with serodiagnosis and discusses sonographic features that may be helpful in differential diagnosis.

Comparison of Long-Term Results of Percutaneous Treatment Techniques for Hepatic Cystic Echinococcosis Types 2 and 3b

OBJECTIVE

The purpose of this study was to determine the long-term results of a modified catheterization technique for percutaneous treatment of hepatic cystic echinococcosis (CE) types 2 and 3b and to retrospectively compare the results of puncture, aspiration, injection, and reaspiration (PAIR); standard catheterization; and the modified catheterization technique.

MATERIALS AND METHODS

Seventy-three patients (37 male, 36 female; 75 cysts) with CE types 2 and 3b who underwent percutaneous treatment from March 1991 to August 2008 were included. Informed consent from all patients and approval of the ethics board were obtained. Patients were 6-79 years old. Twenty-three cysts (30.6%) were treated with PAIR, 26 (34.7%) with standard catheterization, and 26 (34.7%) with the modified catheterization technique. The results of the three techniques were statistically compared.

RESULTS

Among all patients, the cysts decreased in volume by 61.1% (range, 5-100%). Cysts recurred in 11 (47.8%) patients treated with PAIR, three (11.5%) treated with standard catheterization, and one (3.8%) treated with the modified catheterization technique. The recurrence rate was not significantly different between standard catheterization and the modified catheterization technique (p > 0.05), whereas significantly more recurrences developed after PAIR than with the other two techniques (p < 0.05). Twelve (16.4%) major and 16 (21.9%) minor complications developed. Significantly fewer major complications occurred with PAIR than with the modified catheterization technique, but the difference between standard catheterization and the other two techniques was not significant.

CONCLUSION

Treatment of CE types 2 and 3b with the modified catheterization technique was associated with a recurrence rate lower than what is seen with other techniques, and therefore it appears to be a safe, reliable, and efficient alternative.

The Echinococcoses: Diagnosis, Clinical Management and Burden of Disease

The echinococcoses are chronic, parasitic diseases that are acquired after ingestion of infective taeniid tapeworm eggs from certain species of the genus Echinococcus. Cystic echinococcosis (CE) occurs worldwide, whereas, alveolar echinococcosis (AE) is restricted to the northern hemisphere, and neotropical echinococcosis (NE) has only been identified in Central and South America. Clinical manifestations and disease courses vary profoundly for the different species of Echinococcus. CE presents as small to large cysts, and has commonly been referred to as 'hydatid disease', or 'hydatidosis'. A structured stage-specific approach to CE management, based on the World Health Organization (WHO) ultrasound classification of liver cysts, is now recommended. Management options include percutaneous sterilization techniques, surgery, drug treatment, a 'watch-and-wait' approach or combinations thereof. In contrast, clinical manifestations associated with AE resemble those of a 'malignant', silently-progressing liver disease, with local tissue infiltration and metastases. Structured care is important for AE management and includes WHO staging, drug therapy and long-term follow-up for at least a decade. NE presents as polycystic or unicystic disease. Clinical characteristics resemble those of AE, and management needs to be structured accordingly. However, to date, only a few hundreds of cases have been reported in the literature. The echinococcoses are often expensive and complicated to treat, and prospective clinical studies are needed to better inform case management decisions.

Current status of diagnosis and treatment of hepatic echinococcosis

Echinococcus granulosus (E. granulosus) and Echinococcus multilocularis (E. multilocularis) infections are the most common parasitic diseases that affect the liver. The disease course is typically slow and the patients tend to remain asymptomatic for many years. Often the diagnosis is incidental. Right upper quadrant abdominal pain, hepatitis, cholangitis, and anaphylaxis due to dissemination of the cyst are the main presenting symptoms. Ultrasonography is important in diagnosis. The World Health Organization classification, based on ultrasonographic findings, is used for staging of the disease and treatment selection. In addition to the imaging methods, immunological investigations are used to support the diagnosis. The available treatment options for E. granulosus infection include open surgery, percutaneous interventions, and pharmacotherapy. Aggressive surgery is the first-choice treatment for E. multilocularis infection, while pharmacotherapy is used as an adjunct to surgery. Due to a paucity of clinical studies, empirical evidence on the treatment of E. granulosus and E. multilocularis infections is largely lacking; there are no prominent and widely accepted clinical algorithms yet. In this article, we review the diagnosis and treatment of E. granulosus and E. multilocularis infections in the light of recent evidence.

Non-surgical and non-chemical attempts to treat echinococcosis: do they work?

Cystic echinococcosis (CE) and alveolar echinococcosis (AE) are chronic, complex and neglected diseases. Their treatment depends on a number of factors related to the lesion, setting and patient. We performed a literature review of curative or palliative non-surgical, non-chemical interventions in CE and AE. In CE, some of these techniques, like radiofrequency thermal ablation (RFA), were shelved after initial attempts, while others, such as High-Intensity Focused Ultrasound, appear promising but are still in a pre-clinical phase. In AE, RFA has never been tested, however, radiotherapy or heavy-ion therapies have been attempted in experimental models. Still, application to humans is questionable. In CE, although prospective clinical studies are still lacking, therapeutic, non-surgical drainage techniques, such as PAIR (puncture, aspiration, injection, re-aspiration) and its derivatives, are now considered a useful option in selected cases. Finally, palliative, non-surgical drainage techniques such as US- or CT-guided percutaneous biliary drainage, centro-parasitic abscesses drainage, or vascular stenting were performed successfully. Recently, endoscopic retrograde cholangiopancreatography (ERCP)-associated techniques have become increasingly used to manage biliary fistulas in CE and biliary obstructions in AE. Development of pre-clinical animal models would allow testing for AE techniques developed for other indications, e.g. cancer. Prospective trials are required to determine the best use of PAIR, and associated procedures, and the indications and techniques of palliative drainage.

How to build a simple and safe laparoscopic hydatid evaluation system

Background:

One of the most common problems faced in laparoscopic treatment of hydatid cysts is the difficulty in evacuating the particulate contents (daughter cysts and laminated membrane). Although various instruments and laparoscopic techniques have been described to evacuate the contents of hydatid cysts, most are not available at many surgical centers.

Methods:

By assembling disposable, cheap, and available anesthesia equipment with common laparoscopic instruments, a laparoscopic system was made to evacuate the contents of a hydatid cyst. Ten patients with hepatic hydatid disease underwent laparoscopic surgery using this new hydatid system between June 2011 and January 2013.

Results:

The procedure was completely straightforward. Twelve hydatid cysts (2 patients had 2 separated cysts) were evacuated without any spillage. All patients were followed for at least 8 months, with no evidence of recurrence.

Conclusions:

This simple apparatus, which can be assembled anywhere, was safely used to evacuate the contents of hydatid cysts without causing any spillage.

Cystic echinococcosis of the liver: A primer for hepatologists

Cystic echinococcosis (CE) is a complex, chronic and neglected disease with a worldwide distribution. The liver is the most frequent location of parasitic cysts. In humans, its clinical spectrum ranges from asymptomatic infection to severe, potentially fatal disease. Four approaches exist in the clinical management of CE: surgery, percutaneous techniques and drug treatment for active cysts, and the ”watch and wait” approach for inactive cysts. Allocation of patients to these treatments should be based on cyst stage, size and location, available clinical expertise, and comorbidities. However, clinical decision algorithms, efficacy, relapse rates, and costs have never been properly evaluated. This paper reviews recent advances in classification and diagnosis and the currently available evidence for clinical decision-making in cystic echinococcosis of the liver.

Effectiveness of puncture-aspiration-injection-reaspiration in the treatment of hepatic hydatid cysts

BACKGROUND

Hydatid disease of the liver is endemic in cattle rearing areas of the world. A variety of treatment options are available in its management. The common treatment options are medical therapy, surgery and puncture-aspiration-injection-reaspiration (PAIR) therapy.

OBJECTIVES

This study was performed to evaluate the effectiveness of PAIR therapy in the treatment of hepatic hydatid disease.

PATIENTS AND METHODS

This cross sectional study was carried out on 15 consecutive patients (Male: 2, Female: 13; Age group: 11-80 years) with hepatic hydatid disease and were treated by PAIR therapy and followed up for a period of 1 year. The cysts were punctured under local anesthesia with an 18G needle using sonographic guidance. Betadine (10% povidone iodine + 1% free iodine) was used as scolicidal agent and allowed to act for 30 min. Cysts larger than 5 cm (n = 5) were drained using an 8F pig tail catheter. The therapeutic response was studied by assessing the reduction in the cyst size, progressive solidification of the cyst, calcification of the wall and increase in the echogenicity of the cyst with pseudomass appearance on serial ultrasound examinations performed on the next day, after 1 month, at 3 months, 6 months and 1 year after the procedure.

RESULTS

Ten patients (66.7%) had Gharbi type I cysts, two (13.3%) had type II and three (20%) had type III cysts. All the patients (100%) showed reduction in cyst size over a 3-6 month period. Pseudomass appearance with solidification was seen in 73% of the patients and calcification was seen in 46.6%. None of the patients developed anaphylaxis, recurrence or peritoneal seedlings. Pain at the injection site was the most common complication observed.

CONCLUSION

PAIR therapy is an effective minimally invasive treatment for Gharbi type I-III hepatic hydatid cysts. It is a cost effective and safe procedure with significant reduction in the duration of hospital stay.

Cystic echinococcosis in sub-Saharan Africa

Cystic echinococcosis is regarded as endemic in sub-Saharan Africa; however, for most countries only scarce data, if any, exist. For most of the continent, information about burden of disease is not available; neither are data for the animal hosts involved in the lifecycle of the parasite, thus making introduction of preventive measures difficult. Available evidence suggests that several species or strains within the Echinococcus granulosus complex are prevalent in sub-Saharan Africa and that these strains might be associated with varying virulence and host preference. Treatment strategies (chemotherapy, percutaneous radiological techniques, but mainly surgery) predominantly target active disease. Prevention strategies encompass anthelmintic treatment of dogs, slaughter hygiene, surveillance, and health-educational measures. Existing data are suggestive of unusual clinical presentations of cystic echinococcosis in some parts of the continent, for which the causes are speculative.

Justified concern or exaggerated fear: the risk of anaphylaxis in percutaneous treatment of cystic echinococcosis-a systematic literature review

Percutaneous treatment (PT) emerged in the mid-1980s as an alternative to surgery for selected cases of abdominal cystic echinococcosis (CE). Despite its efficacy and widespread use, the puncture of echinococcal cysts is still far from being universally accepted. One of the main reasons for this reluctance is the perceived risk of anaphylaxis linked to PTs. To quantify the risk of anaphylactic reactions and lethal anaphylaxis with PT, we systematically searched MEDLINE for publications on PT of CE and reviewed the PT-related complications. After including 124 publications published between 1980 and 2010, we collected a total number of 5943 PT procedures on 5517 hepatic and non-hepatic echinococcal cysts. Overall, two cases of lethal anaphylaxis and 99 reversible anaphylactic reactions were reported. Lethal anaphylaxis occurred in 0.03% of PT procedures, corresponding to 0.04% of treated cysts, while reversible allergic reactions complicated 1.7% of PTs, corresponding to 1.8% of treated echinococcal cysts. Analysis of the literature shows that lethal anaphylaxis related to percutaneous treatment of CE is an extremely rare event and is observed no more frequently than drug-related anaphylactic side effects.

The risk of anaphylactic shock is the objection most often raised by opponents of percutaneous treatments for cystic echinococcosis, but there are no updated figures on the actual occurrence of anaphylaxis as a complication of this treatment.

To assess the number of lethal and non-lethal anaphylactic reactions following percutaneous aspiration of echinococcal cysts, we systematically reviewed the literature published from 1980–2010.

The analysis of the available literature shows that the risk of severe anaphylactic reactions resulting from percutaneous treatment of echinococcal cysts has been widely exaggerated and the actual risk may be lower than that following administration of certain antibiotics.

Provided adequate stand-by resuscitation measures are available, each time an echinococcal cyst is punctured, fear of anaphylactic shock is no longer justified as an argument to avoid this therapeutic option.

Hydatid cyst disease: optimal management of complex liver involvement

The most frequent location of hydatid cystic lesions is in the liver (up to 80% of cases), followed by the lung (about 20% of cases), and with lower reported incidence, virtually in any other organ or tissue in the body. Therefore, the case an American medical practitioner would most likely encounter, albeit still rare, is a large, symptomatic liver cyst, similar to the one presented in this report. Current techniques and reasoning concerning optimal treatment of liver hydatid cyst disease are revisited, and recommendations based on available literature regarding ideal management of such cases are presented.

Human echinococcosis: a neglected disease

Echinococcosis is among the most neglected parasitic diseases. Development of new drugs and other treatment modalities receives very little attention, if any. In most developed countries, Cystic Echinococcosis (CE) is an imported disease of very low incidence and prevalence and is found almost exclusively in migrants from endemic regions. In endemic regions, predominantly settings with limited resources, patient numbers are high. Whole communities do not have access to appropriate treatment. The choice of treatment modalities is limited because of poor infrastructure and shortage of equipment and drugs. In this context, CE meets the criteria for a neglected disease. Furthermore, the terminology related to the designations around the parasite, its evolution and some therapeutic procedures is not uniform and sometimes inappropriate terms and wrong designations are used based on incorrect concepts. Although all of us know the different aspects of the disease it is pertinent to remember some important points and, above all, to clarify some aspects concerning the hydatid cyst's nomenclature in order to understand better the therapeutic options in the liver locations, particularly the different surgical approaches.

Endoscopic management of biliary parasitic diseases

AIM/MATERIALS AND METHODS: Between January 2000 and June 2007, 3,548 endoscopic retrograde cholangiopancreatography (ERCP) were performed for extrahepatic cholestasis, cholangitis, and choledocholithiasis. The results of ERCPs were evaluated retrospectively and examined carefully to investigate the management and endoscopic therapy of biliary parasites.

RESULTS

Of the 3,548 patients who underwent ERCP, 24 (0.66%) were found to have biliary parasitosis. The mean age of the biliary parasitosis patients (16 women) was 48.6 (15-77) years. Of these 24 cases, 16 patients had hydatid cystic disease (eight with partial obstruction of the biliary tract, and eight with ruptured cysts), four patients had Fasciola hepatica, and four patients had Ascaris lumbricoides infestation. Endoscopic sphincterotomy was performed, after which the choledochus was examined carefully by balloon catheter and basket procedure.

CONCLUSION

The ERCP procedure is very useful in the therapy of biliary parasitic infestations.

Expert consensus for the diagnosis and treatment of cystic and alveolar echinococcosis in humans

The earlier recommendations of the WHO-Informal Working Group on Echinococcosis (WHO-IWGE) for the treatment of human echinococcosis have had considerable impact in different settings worldwide, but the last major revision was published more than 10 years ago. Advances in classification and treatment of echinococcosis prompted experts from different continents to review the current literature, discuss recent achievements and provide a consensus on diagnosis, treatment and follow-up. Among the recognized species, two are of medical importance -Echinococcus granulosus and Echinococcus multilocularis - causing cystic echinococcosis (CE) and alveolar echinococcosis (AE), respectively. For CE, consensus has been obtained on an image-based, stage-specific approach, which is helpful for choosing one of the following options: (1) percutaneous treatment, (2) surgery, (3) anti-infective drug treatment or (4) watch and wait. Clinical decision-making depends also on setting-specific aspects. The usage of an imaging-based classification system is highly recommended. For AE, early diagnosis and radical (tumour-like) surgery followed by anti-infective prophylaxis with albendazole remains one of the key elements. However, most patients with AE are diagnosed at a later stage, when radical surgery (distance of larval to liver tissue of >2cm) cannot be achieved. The backbone of AE treatment remains the continuous medical treatment with albendazole, and if necessary, individualized interventional measures. With this approach, the prognosis can be improved for the majority of patients with AE. The consensus of experts under the aegis of the WHO-IWGE will help promote studies that provide missing evidence to be included in the next update.

Refractory cystobiliary fistula secondary to percutaneous treatment of hydatid cyst: treatment with N-butyl 2-cyanoacrylate embolization

A 27-year-old female with a type 2 hydatid cystic lesion in the liver according to the Gharbi classification (CE 3A according to the WHO classification) was referred for percutaneous treatment after albendazole treatment for 1 year. A catheterization technique was performed but hypertonic saline and alcohol were not given into the cavity due to cystobiliary leakage. During the 4-month follow-up period, sequential cavitography revealed biliary fistula, and bile-stained drainage had not been ceased despite the sphincterotomy, nasobiliary drainage catheter, and plastic stent. Since the patient refused to surgery, we embolized the biliary fistula using N-butyl 2-cyanoacrylate for the first time in the literature. At the 3-month follow-up, the patient's course was uneventful and ultrasound, multidetector-row CT, and MRI examinations revealed no collection in or adjacent to the cavity.

Update on cystic hydatid disease

PURPOSE OF REVIEW

Cystic echinococcosis, or cystic hydatidosis, is a complex, chronic disease with a cosmopolitan distribution. In humans, its clinical spectrum ranges from asymptomatic infection to severe, rarely even fatal disease. Four approaches in clinical management exist: surgery, percutaneous techniques and drug treatment for active cysts, and the so-called watch and wait approach for inactive cysts. Allocation of patients to these treatments should be based on cyst stage, size and location, available clinical expertise and comorbidities. However, clinical decision algorithms, efficacy, relapse rates, and costs have never been properly evaluated.We review the currently available evidence for clinical decision-making and discuss ways to improve standards of care of one of the most neglected infectious diseases.

RECENT FINDINGS

Data are mostly derived from case series and small clinical trials, and treatment guidelines remain at the level of expert opinion. No single high-quality comparative clinical trial of the four treatment options is available to resolve important questions such as stage-specific allocation of treatments, adverse events and long-term relapse rates. Recent work is beginning to acknowledge this problem.

SUMMARY

Currently, four treatment modalities are available for cystic echinococcosis. The level of evidence on which clinicians have to rely is low. For the time being patients should thus be treated in referral centres. Proper comparative clinical trials are urgently needed.

Liver hydatid cyst with transdiaphragmatic rupture and lung hydatid cyst ruptured into bronchi and pleural space

The aim of this case study is to present effectiveness of percutaneous drainage as a treatment option of ruptured lung and liver hydatid cysts. A 65-year-old male patient was admitted with complicated liver and lung hydatid cysts. A liver hydatid cyst had ruptured transdiaphragmatically, and a lung hydatid cyst had ruptured both into bronchi and pleural space. The patient could not undergo surgery because of decreased respiratory function. Both cysts were drained percutaneously using oral albendazole. Povidone-iodine was used to treat the liver cyst after closure of the diaphragmatic rupture. The drainage was considered successful, and the patient had no recurrence of signs and symptoms. Clinical, laboratory, and radiologic recovery was observed during 2.5 months of catheterization. The patient was asymptomatic after catheter drainage. No recurrence was detected during 86 months of follow-up. For inoperable patients with ruptured liver and lung hydatid cysts, percutaneous drainage with oral albendazole is an alternative treatment option to surgery. The percutaneous approach can be life-saving in such cases.

Cystic echinococcosis of the liver and lung treated by radiofrequency thermal ablation: An ex-vivo pilot experimental study in animal models

AIM: To evaluate radiofrequency thermal ablation (RTA) for treatment of cystic echinococcosis in animal models (explanted organs).

METHODS: Infected livers and lungs from slaughtered animals, 10 bovine and two ovine, were collected. Cysts were photographed, and their volume, cyst content, germinal layer adhesion status, wall calcification and presence of daughter or adjacent cysts were evaluated by ultrasound. Some cysts were treated with RTA at 150 W, 80°C, 7 min. Temperature was monitored inside and outside the cyst. A second needle was placed inside the cyst for pressure stabilization. After treatment, all cysts were sectioned and examined by histology. Cysts were defined as alive if a preserved germinal layer at histology was evident, and as successfully treated if the germinal layer was necrotic.

RESULTS: The subjects of the study were 17 cysts (nine hepatic and eight pulmonary), who were treated with RTA. Pathology showed 100% success rate in both hepatic (9/9) and lung cysts (8/8); immediate volume reduction of at least 65%; layer of host tissue necrosis outside the cyst, with average extension of 0.64 cm for liver and 1.57 cm for lung; and endocyst attached to the pericystium both in hepatic and lung cysts with small and focal de novo endocyst detachment in just 3/9 hepatic cysts.

CONCLUSION: RTA appears to be very effective in killing hydatid cysts of explanted liver and lung. Bile duct and bronchial wall necrosis, persistence of endocyst attached to pericystium, should help avoid or greatly decrease in vivo post-treatment fistula occurrence and consequent overlapping complications that are common after surgery or percutaneous aspiration, injection and reaspiration. In vivo studies are required to confirm and validate this new therapeutic approach.

Sonographic spectrum of hydatid disease

Hydatid disease, caused by Echinococcus granulosus, is a parasitic disease that is endemic in many parts of the world. Hydatid cyst demonstrates a variety of imaging features, varying according to growth stage, associated complications, and affected tissue. The radiologic findings range from purely cystic lesions to a completely solid appearance. Ultrasound is the most important imaging modality for liver hydatid disease and clearly demonstrates the floating membranes, daughter cysts, and hydatid sand characteristically seen in purely cystic lesions. The radiologist's familiarity with the imaging findings of the disease is very important for earlier diagnosis and an appropriate treatment. There are several classification schemes for liver hydatid cysts based on their ultrasound appearances; the initial classification by Gharbi et al and the World Health Organization classification are the most commonly preferred. Computed tomography and magnetic resonance imaging play a key role in recognizing the complications such as rupture and infection of cysts associated with hydatid disease. Today, percutaneous treatment of liver hydatid cysts, a safe, easily applicable, and well-tolerated method, has become the most effective and reliable treatment procedure in most cases if the hydatid cyst is viable. In patients treated with the percutaneous treatment technique, a decrease in the dimensions of the cyst, solidification of the cyst contents, and irregularity in the walls of cysts are signs suggestive of cure. The radiologist should also be familiar with the postoperative follow-up ultrasound findings of hydatid cyst to prevent misinterpretation of the hypoechoic, anechoic, or hyperechoic appearance of posttreatment hydatid disease appearance as recurrence.

A complicated postsurgical echinococcal cyst treated with radiofrequency ablation

Surgery of hydatid cysts is often complicated with intrabiliary rupture (IBR), which if not recognized may lead to biliary fistula with rather high rates of morbidity and mortality. We report our experience with the application of radiofrequency (RF) ablation for the treatment of an operated hepatic echinococcal cyst which was complicated with biliocystic communication and cysteocutaneous fistula with bile leakage. RF ablation was performed under CT guidance into the remaining cyst through the cutaneous fistula. Since ablation of the cyst and the fistula the patient has been asymptomatic.

Giant hepatic hydatid cyst with sub-fascial extension treated by open minimally invasive surgery: a case report

INTRODUCTION

Hepatic hydatid disease can be successfully treated by a variety of modalities.

CASE PRESENTATION

We report a case of a 60 year old male with giant hepatic hydatid disease who presented with a huge cystic mass in the upper abdomen. Diagnosis was confirmed by serology, ultrasonography and CT scan. The patient was treated successfully by open minimally invasive surgery with minimum breaching of the peritoneal cavity using a laparoscopic trocar to evacuate the cyst.

CONCLUSION

The use of a laparoscopic trocar through a small abdominal incision in selected patients with hepatic hydatid disease with subfascial extension can be a safe, minimally-invasive option of treatment.

Diagnosis and percutaneous treatment of soft-tissue hydatid cysts

The purpose of this study is to demonstrate and discuss the radiological features of four patients with muscular hydatid disease and to evaluate the results of percutaneous treatment in these patients. Four patients (three female and one male) with six muscular hydatid cysts underwent percutaneous treatment and were followed up. The mean age of patients was 35 years (range: 12-60 years). Type I (n = 2), type II (n = 1), and type III (n = 3) hydatid cysts were observed in the thigh (n = 3) and gluteal (n = 1) region on radiologic examination. All interventions were performed under sonographic and fluoroscopic guidance. According to the type of the cyst, the procedure was carried out by either a "catheterization technique with hypertonic saline and alcohol" or a "modified catheterization technique." The mean cathaterization time was 13.7 days, ranging from 1 to 54 days. The dimensions of the residual cavity were noted at every sonographic control, and an average of 96.1% volume reduction was obtained in six cysts of four patients. No sign of viability was observed during the follow-up period. Cavity infection and cellulitis were observed as complications, which resolved after medical therapy. Percutaneous treatment is a safe and effective procedure in patients with soft-tissue hydatid cysts and should be considered as a serious alternative to surgery.

Hydatid hepatic cysts rupture into the biliary tract, the peritoneal cavity, the thoracic cavity and the hepatic subcapsular space: specific computed tomography findings

BACKGROUND

This study attempts to demonstrate the role of computed tomography in the diagnosis of hepatic hydatid cyst rupture based on specific imaging findings and to propose combinations of the imaging findings diagnostic for specific types of rupture.

METHODS

Eleven patients were studied with computed tomography of the abdomen, with 4-8 mm slice thickness, after the oral administration of contrast material and intravenous contrast material in 6 cases.

RESULTS

Based on a combination of imaging findings the types of hepatic hydatid cyst rupture were: intrabiliary rupture in 7 patients, intraperitoneal rupture in 1 patient, intrathoracic rupture in 1 patient, hepatic subcapsular rupture in 2 patients. Structural deformity of the cyst was present in all cases, combined with: dilatation of the intrahepatic bile ducts (intrabiliary rupture); intraperitoneal fluid collections with diffuse haziness and stranding of the mesenteric fat (intraperitoneal rupture); an inhomogeneous lesion in the thorax with ipsilateral pleural effusion (intrathoracic rupture); a hydatid cyst located peripherally, with discontinuity of its adjacent to the hepatic capsule wall and subcapsular fluid collection (subcapsular rupture). The imaging findings were surgically and pathologically confirmed.

CONCLUSIONS

Using combinations of specific imaging findings we correctly diagnosed the type of hepatic hydatid cyst rupture in all cases.

The usefulness of endoscopic retrograde cholangiopancreatography and (99m)Tc-labeled albumin macroaggregates in diagnosing hydatid disease fistulae

Hydatid disease is an important health problem in areas where it is endemic. There are several therapeutic modalities, the most important being surgery, antibiotherapy, and percutaneous treatment. In recent years percutaneous treatment has become popular, and for this method or surgery it is sometimes lifesaving to know the relation between the biliary ducts and the cyst cavity. The aim of this study was to examine the usefulness of endoscopic retrograde cholangiopancreatography and (99m)Tc-labeled albumin macroaggregates in diagnosing hydatid disease fistulae before percutaneous or surgical treatment. A total of 72 patients diagnosed with hepatic hydatid disease via ultrasound and serologic tests were enrolled in the study. Endoscopic retrograde cholangiopancreatography was successfully performed in all patients. (99m)Tc-labeled albumin macroaggregates also were injected into cysts at a dose of 1.5-2 mCi just before the treatment. All but three patients were treated percutaneously. Scintigraphy of abdominal and thoracic areas was performed with a GE Starcam 3200 XC/T gamma camera at 30 and 120 min after Tc-labeled albumin macroaggregate injections. Endoscopic retrograde cholangiopancreatography revealed communications between biliary ducts and cyst cavities in nine patients (12.5%). However, (99m)Tc-labeled albumin macroaggregates showed not only leakage into the systemic circulation in nine patients but also into the biliary ducts in two (15.4%). In one patient, mild acute pancreatitis occurred as a complication of endoscopic retrograde cholangiopancreatography. No complications of (99m)Tc-labeled albumin macroaggregates injection were seen. Three patients were surgically treated because of clinically manifested cystobiliary fistulae. We conclude that endoscopic retrograde cholangiopancreatography is a gold standard technique for the diagnosis of communication between the biliary duct and the cyst cavity, and (99m)Tc-labeled albumin macroaggregate injection is useful for revealing leakage into the systemic circulation. The diagnosis of biliary fistulae before percutaneous treatment of hydatid disease may enable planning of the optimal therapy.

Cystic echinococcosis in immigrant from Peru: first case treated with percutaneous treatment in Japan

We report a case of cystic echinococcosis (CE) caused by Echinococcusgranulosus, for which a modified percutaneous evacuation (PEVAC) treatment was applied. The patient had immigrated from Peru to Japan and had 2 hydatid cystic masses, 1 located in segment (S)5 of the liver and the other in S3 (5.3 and 3.5 cm in diameter, respectively), both of which were visualized as pseudotumors by ultrasound (US) examinations. Albendazole treatment showed no effects and surgical treatment was refused. After punctuation of the S5 cyst under US guidance and S3 with CT guidance, 10- and 12-French gauge catheters, respectively, with multiple side holes were inserted. About 60 ml of the cyst contents was drawn out from the S5 lesion and 2 ml from the S3 lesion. Using repetitive manual injections and aspiration of small amounts of hypertonic saline, the remaining cyst content was removed as much as possible, after which 20 and 10 ml of 98% ethanol was injected into the S5 and S3 lesions, respectively. A short-term evaluation during the 4 month-period following the procedure using US revealed nearly complete evacuation of the S5 lesion, whereas that at S3 remained as a pseudo-solid mass. We consider that percutaneous treatment is a safe therapeutic modality for hydatid cysts. This is the first case report of CE treated percutaneously in Japan.

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.

Palanivelu hydatid system for safe and efficacious laparoscopic management of hepatic hydatid disease

BACKGROUND

Hydatid disease, being endemic in several areas of the world, is of interest even to surgeons in non-endemic areas because they may encounter the disease due to ease and rapidity of travel as well as immigration. We describe a new device for laparoscopic management of hepatic hydatid disease.

METHODS

The special trocar-cannula system--the Palanivelu hydatid system (PHS)--and the technique of operation are described. A total of 75 patients were operated on using this technique.

RESULTS

In 83.3% of patients, only evacuation of the hydatid cyst by the PHS was done. In 13.7%, this was followed by left lobectomy because the cysts were large, occupying almost the entire left lobe of the liver. The remnant cavity was dealt with by omentoplasty. The average follow-up period was 5.9 years, during which there were no recurrences.

CONCLUSIONS

PHS is successful in preventing spillage, evacuating the contents of hydatid cysts, performing transcystic fenestration, and for dealing with cyst-biliary communications.

Management of hepatic and intracardiac echinococcal cysts: case report and review of the literature

BACKGROUND

Infection with Echinococcus granulosus affects the liver commonly, but disseminated involvement is rare. We describe a 63 year-old man with echinococcal infection producing both hepatic and cardiac involvement that was managed surgically after failed percutaneous hepatic treatment.

METHODS

This report is a case study of a unique surgical problem. Various treatment modalities are reviewed.

RESULTS

The patient was a 63 year-old man from Iraq who immigrated to the United States after becoming infected with Echinococcus granulosus. He had undergone percutaneous management and albendazole therapy prior to presentation for treatment of hepatic hydatid cysts. He continued to have abdominal pain and fever and was referred to our institution. Imaging revealed persistence of the hepatic hydatid cysts, as well as a new finding of an intracardiac hydatid cyst. The patient underwent successful treatment of his complicated hepatic hydatid cysts with pericystectomy and repair of a biliary fistula. The cardiac cyst was removed as well. The patient made an uneventful recovery, and his symptoms resolved.

CONCLUSION

Although rare, echinococcal infection may be encountered in the United States as travel increases to and from regions of the world where the disease is endemic. It is important for surgeons to be familiar with the multiple options for treatment of hydatid disease.

Hydatid cysts: does every picture tell a story?

Ultrasound imaging is an effective aid to the detection of abdominal cystic echinococcosis. Recently, the images produced have provided more information than just a diagnosis. Different cyst morphologies have been classified into types, and such classifications can be considered to represent a natural history of cyst development. Understanding how cyst structures alter with time is crucial to evaluating the effectiveness of different treatment regimes and to understanding natural degeneration of cysts that can occur. However, the developmental events seen in ultrasound need to be matched more closely to immunological and cellular events if we are to have a fuller appreciation of disease progression and regression. At a community level, the relative proportions of cyst types could also provide epidemiological information on disease transmission.

Modified pair technique for treatment of hydatid cysts in the spleen

The aim of this study was to evaluate the results of single-session sclerotherapy with mixture of alcohol and polidocanol and a subsequent injection of albendazole for devisceration of hydatid cysts in the spleen. Eight patients (four women and four men, average age 22.9+/-11.4 with hydatid cyst in the spleen were treated with 10 minutes time of exposure to mixture of ethanol 95% and polidocanol 1%. After that, 2 to 5 ml of albendazole was injected into the cyst cavity. Two patients had 2 cysts. At follow-up the patients were examined with clinical and biochemical examinations, ultrasonography, and serologic test for echinococcal antibody titres. The mean hospital stay was 2.5+/-0.93 days. During the follow-up period, mean cyst diameter decreased from 46+/-16.4 mm to 13.6+/-16.26 mm. In all ten cysts, a reduction of post procedural recolection of fluid over 40% was observed. Five cysts (50%) disappeared during the follow-up period. All cysts (5) smaller then 50 mm in diameter disappeared during follow-up period. After an initial rise, the echinococcal-antibody titres fell progressively and at the last follow-up were negative (< 1: 160) in 7 (88%) patients. No complications were observed, except for pain, fever and urticaria during the first 24-hours after the procedure. Sclerotherapy using only one session and 10 min time of exposure to the mixture of ethanol and polidocanol, and a subsequent injection of albendasole solution represents an effective treatment of hydatid cysts in the spleen. This procedure is even more efficacious for hydatid cyst with diametar smaller then 50 mm.

Viability and Fertility of Human Hepatic Hydatid Cysts

INTRODUCTION

The adequate treatment for hydatidosis requires a knowledge of certain aspects related to the survival of infectious agents, especially protoscoleces. The aim of this study is to evaluate the viability of protoscoleces in human hepatic hydatid cysts in order to determine the prevalence of their fertility and to study the association with variables typical of the host and of the parasite.

MATERIALS

A cross-sectional study was done in biological material (the fluid from human hepatic hydatid cysts). The viability criteria used were: ovoid form, invaginated scolices and intact calcareous corpuscles, the presence of vibrating movements, and the absence of "vital" staining. The cysts were grouped as univesicular cysts (UVC), multivesicular cysts (MVC) and abscessed cysts (LAHO). Fertility was defined as living protoscoleces in relation to the total number of protoscoleces. Descriptive statistics were for the calculation of the prevalence of fertility, analytical statistics for the comparison of groups, and a multivariate analysis for the examination of the association between cyst fertility and clinical variables.

RESULTS

A total of 163 cysts with a median diameter of 15 cm were studied in this way. Of these lesions, 79 (48.5%) were UVC, 54 (33.1%) MVC, and 30 (18.4%) LAHO. On 99 occasions (60.7%), macroscopic communication was evident in the bile duct, and a prevalence of general fertility of 57.1% (94.4% for MVC, 53.2% for UVC, and 0% for LAHO, with a value of P<0.001). Association with location, type, and diameter of the cyst, and presence of biliary communications was verified by applying a bivariate analysis, and association between fertility and the variables of the type of the cyst and the existence of biliary communications was verified employing a multivariate analysis (P values of 0.004 and <0.001, respectively).

CONCLUSIONS

The prevalence of fertility found was low. The main prevalence of fertility was observed in MVCs. Fertility is associated with the type of cyst and the presence of biliary communications.

Laparoscopic management of hepatic hydatid disease

BACKGROUND

Hydatid disease is an endemic condition in several parts of the world. Owing to ease of travel, even surgeons in nonendemic areas encounter the disease and should be aware of its optimum treatment. A safe, new method of laparoscopic management of hepatic hydatid disease is described along with a review of the relevant literature.

METHODS

Sixty-six cases of hepatic hydatid disease were operated on laparoscopically using the Palanivelu Hydatid System. The special trocar-cannula system used and the technique of operation are described.

RESULTS

The majority of the patients presented with pain. Most of the patients had only a single cyst. The right lobe of the liver was most commonly involved. Cysts were bilateral in 4 patients. In 83.3%, simply evacuation of the hydatid cyst by the Palanivelu Hydatid System was done. In 13.7%, this was followed by a left lobectomy, as the cysts were large occupying almost the entire left lobe of the liver. The remnant cavity was dealt with by omentoplasty. The average follow-up period is 5.8 years. There have been no recurrences to date.

CONCLUSION

We recommend Palanivelu Hydatid System for management of hepatic hydatid disease. We have found its efficacy to be optimum for preventing spillage, evacuating hydatid cyst contents, performing transcystic fenestration, and for dealing with cyst-biliary communications.

Modified PAIR technique for percutaneous treatment of high-risk hydatid cysts

PURPOSE

This paper presents a modification of the known method for percutaneous treatment of hydatid cyst, the PAIR technique. It aimed to achieve safe aspiration of large symptomatic cysts and cysts with a danger of impending rupture.

METHODS

We designed a coaxial catheter system to achieve concomitant evacuation of cyst contents while infusing scolicidal agent. Hypertonic saline is used to wash out cyst contents and to kill protoscolices. This was followed by injection of a sclerosant (ethyl alcohol 95%) into the residual cyst cavity to prevent formation of a cyst collection after the procedure. Seventeen cysts in 14 patients were successfully aspirated. Follow-up plain radiographs, ultrasonography and CT were performed weekly in the first 4 weeks and then at 3, 6 and 12 months for all patients. Seven patients (9 drained cysts) were followed up for 2 years and 1 patient for 3 years.

RESULTS

All cysts were successfully aspirated. The following morphologic changes were noticed: a gradual decrease in cyst size (17 cysts, 100%), thickening and irregularity of the cyst wall due to separation of endocyst from pericyst (7 cysts, 41%), development of a heterogeneous appearance of the cyst components (8 cysts, 47%) and development of pseudotumor (2 cysts, 12%). None of the treated cysts disappeared completely. No significant procedure-related complications were encountered.

CONCLUSION

This modified PAIR technique is a reliable method for percutaneous treatment of risky and symptomatic hydatid cysts.

Treatment options for hepatic cystic echinococcosis

A number of surgical and non-surgical options exist to treat cystic echinococcosis of the liver. For decades, surgical excision via a conservative or radical approach was the recommended approach for hepatic hydatid cysts. The availability of chemotherapeutic agents with significant activity against Echinococcus granulosis has made it possible to undertake ultrasound- or computed tomography-guided transhepatic percutaneous drainage (termed puncture, aspiration, injection, and re-aspiration (PAIR)) of hydatid cysts. Pre- and post-intervention chemotherapy with albendazole or mebendazole offers the advantage of reducing the risk of disease recurrence and intraperitoneal seeding of infection that may develop via cyst rupture and spillage occurring spontaneously or during surgery or needle drainage. PAIR appears to have greater clinical efficacy (i.e. a higher incidence of cure), lower rates of major and minor complications, mortality, and disease recurrence, and fewer days of hospitalization compared to patients treated surgically. For patients who fail drug therapy alone, PAIR is a safe and effective procedure of choice for patients with hepatic echinococcosis, and perhaps other anatomic sites of infection such as lung, peritoneum, kidney, and other viscera. Surgery should be reserved for patients with hydatid cysts refractory to PAIR because of secondary bacterial infection or for those with difficult-to-manage cyst-biliary communication or obstruction.