Usefulness of endoscopic metal stent placement for malignant afferent loop obstruction

Background Malignant afferent loop obstruction (mALO) can cause cholangitis, pancreatitis, and perforation due to blind loop dilatation. However, peritoneal dissemination, lymph node metastasis, and recurrence of the tumor are the main causes of mALO, and most cases are in the advanced stage with thoracicoabdominal fluid retention, for which surgery and percutaneous transhepatic treatment are challenging. At our hospital, endoscopic metal stent placement (EMSP) has been applied for such mALO. We retrospectively investigated the usefulness of EMSP for mALO. Methods We conducted a retrospective analysis of 11 mALO patients with EMSP between January 2008 and December 2018. The following items were evaluated: the characteristics of patients, technical success and adverse events of EMSP, clinical efficacy, and outcome after EMSP. Results The surgical procedures and reconstruction methods were distal gastrectomy with Billroth II reconstruction for 3 patients, pancreaticoduodenectomy with modified-Child reconstruction for 7, choledochojejunostomy with Roux-en-Y reconstruction for 1. The cause of mALO was peritoneal dissemination for 6 patients, local recurrence for 3, lymph node metastasis for 1, and afferent loop invasion for 1. EMSP was attempted in 13 sessions for 11 patients, and successful in 12 of 13 sessions. There were no adverse events. The clinical efficacy was high in successful EMSP. The median survival time after EMSP was 118 days. Ten patients died of primary disease and one patient died of uncontrollable cholangitis after the failure of EMSP. mALO recurred and EMSP was repeated for 2 of 10 patients who died of primary disease. Conclusions The success rate of EMSP for mALO was high in patients with poor general conditions due to advanced-stage malignant tumors and it was able to be safely performed, suggesting its high clinical efficacy. The incidence of mALO recurrence after EMSP was low.