Endoscopic stenting of malignant, benign and iatrogenic colorectal disorders: a primer for radiologists

In recent years, endoscopic placement of intraluminal stents is increasingly used to manage a widening range of colorectal disorders. Self-expanding metal stents represent an established alternative to surgery for the palliation of unresectable carcinomas and currently allow a "bridge-to-surgery" strategy to relieve large bowel obstruction and optimise the patients' clinical conditions before elective oncologic resection. Additionally, intraluminal stents represent an appealing option to manage obstructing extracolonic tumours and selected patients with benign conditions such as refractory anastomotic strictures and post-surgical leaks.This educational paper reviews the technical features and current indications of colorectal stenting and presents the expected and abnormal radiographic, CT and MRI appearances observed during the endoscopic management of malignant, benign and iatrogenic colonic disorders with stents. The aim is to provide radiologists with a thorough familiarity with stent-related issues, which is crucial for appropriate reconstruction of focused CT images, correct interpretation of early post-procedural studies and elucidation of stent-related complications such as misplacement, haemorrhage, perforation, migration and re-obstruction.