Clinical management for malignant afferent loop obstruction.

Afferent loop obstruction (ALO) is defined as duodenal or jejunal mechanical obstruction at the proximal anastomosis site of a gastrojejunostomy. With advances in chemotherapy, the incidence of malignant ALO is increasing. Malignant ALO can be complicated by ischemia, gangrenous bowel, pancreatitis, and ascending cholangitis. Moreover, the general condition of patients with recurrent cancer is often poor. Therefore, accurate and rapid diagnosis and minimally invasive treatments are required. However, no review articles on the diagnosis and treatment of malignant ALO have been published. Through literature searching, we reviewed related articles published between 1959 and 2020 in the PubMed database. Herein, we present recent advances in the diagnosis and treatment of malignant ALO and describe future perspectives. Endoscopic transluminal self-expandable metal stent (SEMS) placement is considered the standard treatment for malignant ALO, as this procedure is well established and less invasive. However, with the development of interventional endoscopic ultrasound (EUS) in recent years, the usefulness of EUS-guided gastrojejunostomy has been reported. Moreover, through indirect comparison, this approach has been reported to be superior to transluminal SEMS placement. It is expected that a safer and less invasive treatment method will be established through the continued advancement and innovation of interventional endoscopy techniques.