A modified 'Puncture-Aspiration-Injection-Re-aspiration' (PAIR) technique to treat Hepatic Cystic Echinococcosis: A retrospective case series and narrative review.

Abstract

Percutaneous treatments (PTs) are established minimally invasive options for the management of hepatic cystic echinococcosis (HCE). Conventional techniques include puncture, aspiration, injection, and re-aspiration (PAIR), which relies on scolicidal agents, and puncture, aspiration, injection, and drainage (PAID), which uses prolonged catheter drainage to evacuate cyst contents. In this study, we describe our experience with a modified PAIR technique for the treatment of hepatic cystic echinococcosis. Eight patients with 19 cysts were initially included, and outcomes were analyzed in 6 patients with 9 cysts who had complete follow-up imaging.Under CT guidance, a transhepatic puncture of the cyst was performed. Partial aspiration was followed by injection of hypertonic saline. After cystography, an 8-French catheter was introduced to replace the 18-gauge needle, allowing controlled aspiration. The injection and aspiration sequence was repeated three to four times. The catheter was removed early after complete cyst content evacuation. In cysts larger than 10 cm, 95% ethanol was used as the scolicidal agent.Follow-up imaging showed a significant reduction in cyst volume. Outcomes achieved with this modified PAIR technique were compared with previously reported percutaneous HCE treatment series in the literature and appeared to fall within the range of outcomes reported in prior percutaneous series. Notably, this technique enabled successful treatment of a complicated cyst associated with a gastric fistula in a single patient.Percutaneous management of HCE continues to evolve, and modified techniques allow tailored treatment based on cyst characteristics. Our modified PAIR approach proved effective for both simple and multivesicular cysts and demonstrated technical feasibility in a single complicated case with gastric fistula.