Gastrointestinal stenting: Current status and imaging features

CIRSE Standards of Practice on Placement of Upper Gastrointestinal Stents

BACKGROUND

Image-guided insertion of stents in the upper gastrointestinal trunk is an effective, minimally invasive treatment option to provide immediate relief of symptoms caused by upper gastrointestinal tract obstruction related to advanced-stage malignant causes or benign causes that lead to lumen narrowing.

PURPOSE

This document, as with all CIRSE Standards of Practice documents, is not intended to impose a standard of clinical patient care but will recommend a reasonable approach to best practices for performing stenting of the upper gastrointestinal tract, namely the oesophageal and gastroduodenal segments. Our purpose is to provide up-to-date recommendations for placement of upper gastrointestinal tract stents based on the previously published guidelines on this topic in 2005 and 2007.

METHODS

The writing group was established by the CIRSE Standards of Practice Committee and consisted of a group of internationally recognised experts in performing upper gastrointestinal stenting. The writing group reviewed the existing literature using PubMed to search for relevant publications in the English language up to September 2021. The final recommendations were formulated through consensus.

CONCLUSION

Insertion of stents in the oesophageal and gastroduodenal tracts has an established role in the successful management of malignant or benign obstructions. This Standards of Practice document provides up-to-date recommendations for the safe performance of upper gastrointestinal stent placement.

Short benign ileocolonic anastomotic strictures - management with bi-flanged metal stents: Six case reports and review of literature

BACKGROUND

The endoscopic management of benign short post-anastomotic ileocolonic stricture (PAICS) that is refractory to primary and secondary treatment modalities remains challenging. The lumen-apposing metal stent (LAMS) is a novel device recently developed for therapeutic gastrointestinal endoscopy. LAMSs have demonstrated significantly better results with regard to stent migration than fully covered self-expandable metal stents (FCSEMSs).

CASE SUMMARY

This article presents six cases of symptomatic PAICS successfully treated with a LAMS and a review of the relevant literature. We report a life-saving technique not previously documented and the use of technology to improve patient outcomes. The six patients (median age, 75 years) suffered from vomiting, constipation and recurrent abdominal pain, with symptoms starting 23-25 wk post-surgery. The median stricture length was 1.83 cm. All six patients underwent successful and uneventful bi-flanged metal stent (BFMS)-LAMS placement for benign PAICS. All patients remained asymptomatic during the three months of stent indwelling and up to a median of 7 mo after stent removal. According to the literature, the application of LAMS for PAICS is associated with a < 10% risk of migration and a < 5% risk of bleeding. Conversely, FCSEMS has a high migration rate (15%-50%).

CONCLUSION

The evolving role of interventional endoscopy and the availability of LAMSs provide patients with minimally invasive treatment options, allowing them to avoid more invasive surgical interventions. The BFMS (NAGI stent) is longer and larger than the prototype AXIOS-LAMS, which should be considered in the management of short ileocolonic post-anastomotic strictures longer than 10 mm and shorter than 30 mm.

Recent Updates in Gastrointestinal Stent Placement from the Esophagus to the Colon: A Radiological Perspective

Fluoroscopic-guided stent placement has become an advantageous treatment option for diverse gastrointestinal disorders. In addition to palliative stent placement in patients with inoperable cancers, stenting has gradually expanded to other conditions, including as a bridge to surgery, as well as in patients' benign lesions and anastomotic strictures or leaks. This narrative review describes the indications, efficacy and safety of stent placement from the esophagus to the colon, including current recommendations, recent updates, and novel stents.

Feasibility and safety of self-expandable metal stent in nonmalignant disease of the lower gastrointestinal tract

In recent years, self-expandable metal stents (SEMSs) have been employed to treat benign gastrointestinal strictures secondary to several conditions: Acute diverticulitis, radiation colitis, inflammatory bowel disease (IBD), and postanastomotic leakages and stenosis. Other applications include endometriosis and fistulas of the lower gastrointestinal tract. Although it may be technically feasible to proceed to stenting in the aforementioned benign diseases of the lower gastrointestinal tract, the outcome has been reported to be poor. In fact, in some settings (such as complicated diverticulitis and postsurgical anastomotic strictures), stenting seems to have a limited evidence-based benefit as a bridge to surgery, while in other settings (such as endometriosis, IBD, radiation colitis, etc.), even society guidelines are not able to guide the endoscopist through decisional algorithms for SEMS placement. The aim of this narrative paper is to review the scientific evidence regarding the use of SEMSs in nonmalignant diseases of the lower gastrointestinal tract, both in adult and pediatric settings.

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.

Management of colon stents based on Bernoulli's principle

BACKGROUND AND AIMS

The colonic self-expanding metal stent (SEMS) has been widely used for "bridge to surgery" and palliative therapy. However, if the spread of SEMS is insufficient, not only can a decompression effect not be obtained but also perforation and obstructive colitis can occur. The mechanism of occurrence of obstructive colitis and perforation was investigated by flow dynamics.

METHODS

Bernoulli's principle was applied, assuming that the cause of inflammation and perforation represented the pressure difference in the proximal lumen and stent. The variables considered were proximal lumen diameter, stent lumen diameter, flow rate into the proximal lumen, and fluid density. To model the right colon, the proximal lumen diameter was set at 50 mm. To model the left-side colon, the proximal lumen diameter was set at 30 mm.

RESULTS

For both the right colon model and the left-side colon model, the difference in pressure between the proximal lumen and the stent was less than 20 mmHg, when the diameter of the stent lumen was 14 mm or more. Both the right colon model and the left-side colon model were 30 mmHg or more at 200 mL s^-1 when the stent lumen was 10 mm or less. Even with an inflow rate of 90-110 mL s^-1, the pressure was 140 mmHg when the stent lumen diameter was 5 mm.

CONCLUSION

In theory, in order to maintain the effectiveness of SEMS, it is necessary to keep the diameter of the stent lumen at 14 mm or more.

Self-Expanding Metal Stenting in the Management of a Benign Colonic Stricture

Colonic postanastomotic strictures occur in 1.5–8% of patients following colorectal surgery. Traditionally, colonic strictures were treated by multiple modalities including endoscopic dilatation. Self-expanding metal stents (SEMS) have been indicated in the management of benign colonic strictures; however, there are limited available data with regard to their efficacy. We present the case of a 68-year-old male who had perforated sigmoid diverticulitis followed by Hartmann's procedure with eventual reanastomosis 6 months later. He subsequently developed benign colonic stricture, which was treated with a metal stent. SEMS are associated with a low mortality rate and are appropriate in treating acute colonic obstruction as a result of benign stricture in the setting of postanastomosis.