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- Materials and Methods
- Declaration of Interests
Background. Cystic echinococcosis (CE) of the liver can be treated with ultrasound-guided puncture, aspiration, injection, and re-aspiration (PAIR), with surgery and with benzimidazole derivatives. The aim of this study was to review available data concerning treatment modality and outcome for patients treated for CE of the liver in a Danish tertiary reference center.
Methods. A search was made for patients treated for CE infection between January 1, 2002 and January 1, 2010. All relevant patient records and radiology exams were scrutinized and all cysts were re-classified according to the WHO-IWGE, blinded as to which treatment the patient had received. PAIR was performed as a first choice treatment and surgery was reserved for cases where PAIR was impossible. Inactive cyst stages received medical treatment only.
Results. The search revealed 26 cases with confirmed CE of the liver. Nine patients underwent PAIR and nine patients surgery as a first choice treatment. Three patients were treated with PAIR secondary to surgery and one patient was treated with surgery secondary to PAIR. For all PAIR treatments, the success rate was 58% regardless of cyst stage and for surgery the success rate was 70%. The difference between the rates was not statistically significant (p = 0.67).
Conclusion. CE is a rare disease in Denmark and our study is the first describing clinical management of CE in our institution.
Cystic echinococcosis (CE) is endemic in parts of Africa and Europe, the Middle East, large parts of Asia, Latin America, and Australia. In Scandinavia, almost all cases are imported.
CE is caused by an infection with the cestode Echinococcus granulosus. It mainly involves the liver (70% of cases) and the lungs (10% of cases), but can also be found in several other organs.1,2 CE may cause major morbidity and can be fatal. However, many cases are silent and undiagnosed for years and even decades. Symptoms at presentation depend on cyst location and size.
Treatment of hepatic CE can be surgical, medical with benzimidazoles, and/or by means of percutaneous ultrasound-guided puncture, aspiration, injection, and re-aspiration (PAIR).
Wherever possible, surgery or, with increasing frequency, PAIR is performed to obtain cure.3 This practice was implemented in the 1990s in Copenhagen, Denmark, the method of choice being aspiration of cyst contents and injection of hypertonic saline as a scolicidal agent in one session according to the WHO guidelines,2 in combination with albendazole.
The aim of the study was to review available data on treatment modality and results for patients treated for CE of the liver in the period between January 2002 and January 2010 at Rigshospitalet, a tertiary reference center in Copenhagen, Denmark.
- Top of page
- Materials and Methods
- Declaration of Interests
Our study is the first to review clinical practice for CE in Denmark, where surgery, medical treatment, and PAIR are all available treatment options.
The current recommendations from WHO are that stages CE1 and CE3A are appropriate for PAIR.5 PAIR is contraindicated at stages CE4 and CE5 because these are inactive stages of the infection, where treatment is unnecessary unless the cysts are complicated. It remains debatable whether PAIR should be recommended for WHO stages CE2 and CE3B. A recent retrospective study6 reported unsuccessful outcome of PAIR in 20% of 77 cysts, which were in majority WHO stages CE2 and CE3B.
In our study, PAIR was performed at CE stages CE1-CE3B, the majority being at stages CE1 and CE3A. However, also stages CE2 and CE3B were punctured, in contrast to standard WHO recommendations (see above). This may be due to an inaccurate retrospective classification.
Importantly, the median duration of hospital admission after PAIR was shorter than after surgery.1,3,7
In another recent large prospective long-term study,8 a modified technique of PAIR, D-PAI (double percutaneous aspiration and injection of ethanol in the cyst cavity without re-aspiration) was performed on 151 viable (stages CE1, CE2, and CE3) CE cysts. The authors reported excellent results, with disappearance of the cysts in 48.4% of cases, solidification of cysts in 46.2% and liquid component (but inactivity of CE cysts) in 5.3% of patients. Surprisingly, they did not classify WHO CE3 cysts into CE3A or CE3B cysts. A third study recently reported failure of PAIR in CE2 and CE3b cysts.9
Seven patients received albendazole as their only treatment. Except for one patient (drop-out) all cysts were inactive on initiation of medical therapy (stages CE4 and CE5). For these patients albendazole treatment had been started based on a positive serology and clinical symptoms in spite of sonographic appearance (CE4 and CE5) that would not normally prompt medical treatment. As this is a retrospective study, it is important to underline that the clinicians have not been uniformly guided by the ultrasound stage of the CE cysts.
The efficacy of albendazole treatment administered alone is unclear. A recent systematic review of albendazole treatment of 1,159 CE cysts suggested an effect for active CE1 cysts but further studies are needed.10 It has previously been attempted to add praziquantel—a medicament primarily used for schistosomiasis—to albendazole to enhance its scolicidal effect, although there is still insufficient evidence to recommend it as adjuvant treatment.11
Treatment with mebendazole and albendazole tends to fail at stages CE2 and CE3B.10,12
Our patients were generally treated and followed up in the outpatient clinic for at least 2 years even when considered cured for CE at an earlier stage. We included the follow-up time in the total treatment period for each patient, thus the true duration of effective treatment and follow-up may be overestimated and should be interpreted with caution. A longer follow-up is recommended by experts.5
The main limitations of our study are caused by the retrospective nature and the limited number of patients available. Medical treatment, patient history, and reported duration of symptoms were not reported in a standardized manner in the medical records. Importantly, not all the cysts included in this study had been classified prospectively according to the WHO-IWGE classification. This is a notable limitation as the recently proposed WHO-IWGE classification has important implications for prognosis and choice of treatment.5
As there are no clinical trials comparing all treatment modalities side by side, it is still unclear which treatment would be the best option, but regarding efficacy, the mere fact that PAIR and surgical patients were hospitalized for 1 and 12 days respectively points at PAIR as the primary choice, when possible. A useful summary of recommendations according to stage and type of CE for the different treatment modalities is available in recent reviews.5,13
CE is a rare disease in Denmark with most patients being immigrants. We recommend that current international recommendations for staging and treatment be adhered to in a prospective manner, so that outcome may be optimized for patients with CE.