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

Background: Surgery is the treatment of choice in echinococcal cysts with cystobiliary fistulas. PAIR (puncture, aspiration, injection, and reaspiration of scolecidals) is contraindicated in these cases. Aim: To evaluate a modified PAIR method for percutoneous treatment of multivesicular echinococcal cysts with or without cystobiliary fistulas which contain non-drainable material. Patients: Twelve patients were treated: 10 patients with multivesicular cysts which contained non-drainable material and were complicated by spontaneous intrabiliary rupture, secondary cystobiliary fistulas, cyst infection, or obstructed portal or hepatic veins; and two patients with large univesicular cysts and a ruptured laminated membrane, one obstructing the portal and hepatic veins and one a suspected cystobiliary fistula. Methods: The methods used, termed PEVAC (percutaneous evacuation of cyst content), involved the following steps: ultrasound guided cyst puncture and aspiration of cyst fluid to release intracystic pressure and thereby to avoid leakage; insertion of a large bore catheter; aspiration and evacuation of daughter cysts and endocyst by injection and reaspiration of isotonic saline; cystography; injection of scolecidals only if no cystobiliary fistula was present; external drainage of cystobiliary fistulas combined with endoprosthesis or sphincterotomy; catheter removal after complete cyst collapse and closure of the cystobiliary fistula. Results: In a 11 12 patients initial cyst size was 13.1 (6-20) cm (mean (range)). At follow up 17.9 (4-30) months after PEVAC, seven cysts had disappeared and five cysts had decreased to 2.4 (1-4) cm (p=0.002). In eight patients with multivesicular cysts, a cystobiliary fistula, and infection, cyst size 12.5 (6-20) cm, catheter time 72.3 (28-128) days, and hospital stay 38.1 (20-55) days. At was 17.3 (4-28) months of follow up, six cysts had disappeared and in two cysts residual size was I and 2.9 cm, respectively (p=0.012). In four patients without a cystobiliary Fistula, cyst size was 14.4 (12.7-16) cm, catheter time 8.8 (3-13) days, and hospital stay 11.5 (8-14) days. At 19.3 (9-30) months of follow up, one cyst had disappeared and three cysts were 85 (69-94)% smaller (2.2 (1-4) cm) (p=0.068). Conclusion: PEVAC is a safe and effective method for percutaneous treatment of multivesicular echinococcal cysts with or without cystobiliary fistulas which contain non-drainable material.