A detailed guide to endoscopic colonic stent insertion in obstructing colorectal cancer

Colonic self-expandable metal stent (SEMS) insertion is a viable management option in the treatment of malignant large bowel obstruction (LBO) in select patients. The most common indication for colonic SEMS insertion is malignant LBO in patients with metastatic disease with a palliative intent. With our method, a long length 0.035 inch guidewire with a hydrophilic tip is required to cannulate the tumour lumen. We most often utilise the WallFlexTM Colonic Stent (Boston Scientific), an uncovered nitinol SEMS which is commonly used in Australia. We also recommend that biliary access catheters, such as those used for endoscopic retrograde cholangiopancreatography (ERCP), should be available to facilitate contrast injection during fluoroscopy, with image intensifier available in the theatre or endoscopy suite. The patient can be positioned either in the lateral decubitus or supine frog-leg position, either under general anaesthetic or sedation depending on the clinical scenario and endoscopist preference. There are three main steps of SEMS insertion: guidewire cannulation of the obstruction, fluoroscopy and SEMS deployment. This article provides a breakdown of each step in detail, with troubleshooting of common pitfalls which may be encountered at each stage during a through-the-scope (TTS) insertion of a colonic SEMS. Images taken during each step are provided to aid visualisation of each stage of the procedure.