Metal stents for malignant colorectal obstruction

Abstract

Malignant obstruction of the colon occurs in 7-25% of patients with colorectal cancer. As emergency laparotomy is reported to have relatively high morbidity and mortality rate, there is a need for alternative procedures with reduced complication rates. Over the last decade colorectal stenting has been reported as an alternative endoscopic method to relieve acute colonic obstruction. With the availability of more sophisticated stents and stent delivery systems, this approach has been used as a palliative method and as a pre-operative bridge to facilitate one-stage surgical resection of primary colonic tumors. Technical and clinical successes have been reported in 80-100% of treated patients. Distal lesions are more common and theoretically easier to stent although lesions within the ascending colon have been successfully managed. Minor complications include transient anorectal pain, tenesmus and rectal bleeding. However, stent migration and colonic perforation are also well recognized. Despite the fact that no randomized controlled studies have yet been performed, literature data show that colonic stenting is a safe and effective procedure and can reduce costs, avoiding the need for colostomy and improving the quality of life of patients with advanced disease.

Preoperative colonic stenting: how, when and why?

“…Recently, because of increased awareness of the role of colonic stenting in the preoperative and palliative setting, an increasing number of dedicated colonic stents have been introduced into the clinical setting (Table 1) [17,22,25]. The Enteral Wallstent (Boston Scientific, Natick, Massachusetts, USA) is delivered using a 10 Fr through-the-scope (TTS) delivery system that fits through a 3.7-mm working channel of an endoscope.…”

“…These advantages are specially recognized when the obstruction is proximal to the rectosigmoid, or in patients with very angulated rectosigmoid anatomy [17,22]. There are no randomized clinical data, however, formally comparing fluoroscopic guidance with endoscopic/fluoroscopic guidance for the placement of colonic stents.…”

“…It is recognized that emergency abdominal surgery is associated with a higher risk of mortality and complications than if that same surgery were performed on an urgent or elective basis [4]. These data reflect the negative impact of an advanced neoplasm and its consequent electrolyte imbalances, deficient nutritional status and fecal loading of an unprepared colon which, in the majority of cases, involves the creation of a diverting colostomy to avoid breaking-down of the colonic anastomosis [17]. Therefore, a technique that provides alleviation of obstruction while allowing for surgery to be delayed may be useful in this setting.…”

“…When radiologic placement is planned, the colonic obstruction is located fluoroscopically using water-soluble contrast medium and the stricture is passed with a guidewire, over which the stent is inserted into the obstruction and released under fluoroscopic guidance [17,22]. Using the combination of endoscopic and fluoroscopic guidance, the distal end of the obstruction is documented endoscopically.…”

“…Then the stent is deployed under direct endoscopic and fluoroscopic guidance using a 'throughthe-scope' stent-delivery system. If the stent-delivery system cannot fit through the operating channel of the endoscope, then the endoscope is removed over the wire and the stent is delivered over the wire and deployed under fluoroscopic guidance [17,22].…”