The use of stents throughout the gastrointestinal tract has evolved over the past century. The evolution of endoscopic ultrasound and significant improvements in stent design are key factors that have allowed endoscopists to drive the use of stents in gastroenterology into new directions. Endoscopic creativity remains crucial in the evolution of any new endoscopic technology. Finally, the use of multidisciplinary teams, including endoscopists, radiologists, and surgeons, allows for the exchange of ideas and procedural planning necessary for successful innovation.
For more than a century, stents have been used for a variety of clinical indications, both benign and malignant, in the gastrointestinal (GI) tract. The principle is rather simple: an occluded lumen is bypassed by the placement of a prosthesis, essentially creating a new pathway for the flow of food, stool, bile, and pancreatic juice. Although the basic premise behind stenting within the GI tract has not changed over time, the stents themselves have.
For example, the earliest stents used within the esophagus were fashioned from ivory and sandalwood. In the 1970s, small-diameter, rigid, plastic stents requiring preassembly were used within the esophagus. The past 40 years have witnessed the progression from these devices to self-expanding stents made from various metals and plastics. Self-expanding metal stents (SEMS) for use in the esophagus are now available in both partially and fully covered versions.
Technological modifications in stent design have not been limited to the esophagus nor have they been limited to SEMS. Stents designed for the pancreaticobiliary tree, colon, and duodenum have all witnessed changes over the past 40 years. Plastic stents are now available in straight, single, and double pigtail versions. These changes in stent technology along with changes in endoscopy have opened the door for novel (and off-label) uses of these devices throughout the GI tract. This article attempts to characterize some of the novel and unique uses of endoprostheses, both plastic and SEMS as well as self-expanding plastic stents (SEPS), throughout the GI tract.
Bariatric surgery
The obesity epidemic throughout North America has resulted in increased performance of bariatric surgery. The most common operation performed is the roux-en-Y gastric bypass (RYGB). Although high rates of success have been seen in terms of loss of excess weight and resolution of diabetes, operative complications can occur in up to 9% of patients. Anastamotic leaks at the gastrojejunostomy are one such complication ( Fig. 1 ) and recent reports suggest significant rates of successful treatment following the placement of covered SEMS or SEPS. In one of the largest series to date, Eubanks and colleagues reported an 84% rate of leak closure in 19 patients who had undergone placement of a covered SEMS or SEPS for the treatment anastamotic leaks following RYGB. In addition, immediate symptomatic improvement occurred in 90% of the treated patients and 79% had oral feeding initiated once the stent had been placed. Stent migration occurred in 58% of the stents placed with 3 patients requiring surgical removal for migration into the small intestine.
Stent placement for managing anastamotic leaks following RYGB is straightforward. Because of the postsurgical nature of the intestine at the time of endoscopy, the most significant challenge tends to be identifying the gastrojejunostomy and Roux limb. Because the leaks can be significant, it is common to visualize the peritoneal cavity at the time of endoscopy (see Fig. 1 ). Once the Roux limb has been entered, however, marking the distal margin of anticipated stent placement with either submucosal contrast injection or hemoclip placement is performed. A wire guide can then be left in place and the stent deployed in the usual fashion under fluoroscopic and, in some cases, endoscopic control. If fluoroscopy alone is used the proximal aspect of anticipated stent placement, typically within the mid to distal esophagus to anchor and potentially minimize risk of migration, should be marked as well. The authors select the largest caliber stent available to decrease the risk of stent migration. An upper GI series can be performed immediately following stent placement to confirm that the leak has been sealed and, if so, the stent is left in place for 6 weeks ( Fig. 2 ). Migrated stents can be retrieved endoscopically or, if unsuccessful, surgically.
In patients who have developed chronic fistula the duration of stent placement may be considerably longer (up to months) and may require adjuvant therapy, such as application of tissue adhesives.
Luminal reconstitution
SEPS and covered SEMS have been used in luminal reconstitution, both in the colon and esophagus. On occasion, patients who have undergone segmental colonic resection can present with complete obstruction of the surgical anastamosis. This presentation is likely caused by chronic inflammation and scarring at the anastamosis, poor surgical technique, or regional ischemia. Similarly, patients with a history of caustic ingestion, mediastinal radiation, or desquamating inflammatory processes of the esophagus may present with a complete esophageal obstruction ( Fig. 3 ). Although a complete postsurgical colonic anastamotic obstruction can be easily treated with a diverting ileostomy, a complete esophageal obstruction presents a greater clinical challenge and may require esophagectomy, colonic interposition, or the creation of a spit fistula and feeding via a gastrostomy.
Several reports have appeared in the literature describing bidirectional endoscopy, either through the ileostomy and rectum ( Figs. 4 and 5 ) or mouth and through a gastrostomy tract (see Fig. 3 ), with subsequent luminal recanalization. Much like the placement of an endoscopic gastrostomy, the endoscopes are brought within millimeters of each other at the site of stenosis. In most cases, transillumination through the stenosis can be recognized and an endoscopic ultrasound needle is passed through the bowel wall under direct endoscopic and fluoroscopic control. A wire can then be passed through the needle and grasped using a snare passed through the second endoscope. Placement of double pigtail stents through the newly formed lumen can then be performed followed weeks later by the placement of a SEPS or covered SEMS. Pneumoperitoneum or pneumomediastinum can be seen (see Fig. 4 ) following luminal recanalization, although peritonitis and mediastinitis typically do not occur.
Luminal reconstitution
SEPS and covered SEMS have been used in luminal reconstitution, both in the colon and esophagus. On occasion, patients who have undergone segmental colonic resection can present with complete obstruction of the surgical anastamosis. This presentation is likely caused by chronic inflammation and scarring at the anastamosis, poor surgical technique, or regional ischemia. Similarly, patients with a history of caustic ingestion, mediastinal radiation, or desquamating inflammatory processes of the esophagus may present with a complete esophageal obstruction ( Fig. 3 ). Although a complete postsurgical colonic anastamotic obstruction can be easily treated with a diverting ileostomy, a complete esophageal obstruction presents a greater clinical challenge and may require esophagectomy, colonic interposition, or the creation of a spit fistula and feeding via a gastrostomy.
Related posts:
Pancreaticobiliary and Gastrointestinal Stents
Expandable Metal Stents: Principles and Tissue Responses
Expandable Stents for Benign Esophageal Disease
Plastic Biliary Stents for Malignant Biliary Diseases
Expandable Metal Stents for Benign Biliary Disease
Self-Expandable Metal Stents for Malignant Distal Biliary Strictures
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