A pelvic abscess (PA) is usually the advanced stage of an abdominal infection. PA drainage (PAD) poses a technical challenge because of the surrounding anatomical and vascular structures. Although historically PA has been managed by surgical intervention, now the less invasive methods are also widely accepted. The percutaneous drainage under ultrasound (US) or computed tomography (CT) guidance has been the standard therapy for treatment of PA [1]. Percutaneous approaches include the transabdominal anterior and transgluteal posterior routes wherein the former is limited by organ interposition and latter is burdened by a high risk of sciatic nerve injury. Even when the procedure is technically and clinically effective, drainage of a deep PA is followed by a prolonged and frequently painful recovery period. The transvaginal approach has been described as an alternative route to overcome such issues; however, implanting a stent or tube in the vagina is difficult [2].

Endoscopic ultrasound (EUS) offers the technical advantage of avoiding passage through other organs, as most PAs are within reach of an echoendoscope. The endoscopic ultrasound-guided PAD (EUS-PAD) is a drainage method that was first described by Giovannini et al. in 2003. It is a technique that can overcome the problems of surgical and percutaneous drainage [3]. Its procedure uses an echoendoscope to visualize an area of interest for needle insertion and placement of a stent, catheter, or both for drainage of the target abscess. It is a safe and less stressful alternative for percutaneous and surgical drainage with favorable long-term results. It should be considered as a viable option for PAD [4]. Nonetheless, there are only a few reports about the usefulness of EUS-PAD in Japan [5], [6], [7]. Therefore, this retrospective study conducted in our hospital aimed to determine the safety and effectiveness of EUS-PAD.