Percutaneous Drainage in Hepatic Hydatidosis-The PAIR Technique: Concept, Technique, and Results

J Clin Exp Hepatol. 2021 Sep-Oct;11(5):592-602. doi: 10.1016/j.jceh.2021.05.005. Epub 2021 May 26.

Abstract

Over decades, surgery has been the only accepted mode of treatment for liver hydatid cysts. It had been a surgical dogma for a long that hydatid disease is an absolute contraindication for needle puncture/aspiration as it can cause anaphylaxis, death, and dissemination. We envisaged prospectively perform percutaneous drainage as a primary form of treatment for hepatic hydatidosis. Through extensive and very careful experimentation, we proved that aspiration of hydatid cysts can be performed safely and is the ideal way to manage a subset of patients with hydatid cysts in the liver. The patient and cyst characteristics good and not good for percutaneous drainage were carefully selected. The procedure of percutaneous drainage of hepatic hydatid cysts involves four sequential steps as defined in the alphabets of the title PAIR, denoting puncture (P), Aspiration (A), Instillation (I), and Reaspiration (R). During and postprocedure, we enforced strict monitoring given the anticipated anaphylaxis. The first PAIR procedure was performed in June 1988. The results of percutaneous drainage of 21 cysts in 12 patients were reported in 1991. Next, a prospective study was done to show that concomitant Albendazole therapy is recommended as an adjuvant to percutaneous drainage for hepatic hydatidosis. In a seminal prospective study comparing percutaneous drainage and surgery, we showed that percutaneous drainage is as good as surgery in the management of uncomplicated hydatid cysts with fewer complications and shorter hospital stays. Lastly, long-term follow-up results of percutaneous drainage on a large cohort of patients with hepatic hydatid cysts were reported, with excellent results and no evidence of local, peritoneal or systemic dissemination. Based on these data percutaneous drainage, the so-called PAIR technique has established itself as a novel therapeutic advance in hepatic hydatid disease.

Keywords: E. granulosus, Echinococcus granulosus; PAIR, denoting puncture (P), Aspiration (A), Instillation (I), and Reaspiration (R); SKIMS, Sher-i-Kashmir Institute of Medical Sciences; cystic echinococcosis; hydatid cyst; hydatid disease; pair technique; percutaneous drainage.