Gastrointestinal (GI) leaks and fistulas may complicate GI surgical procedures including intestinal resections and bariatric procedures. GI perforations are a common complication of endoscopic procedures. These conditions may also develop due to infection, inflammation or increased intestinal pressure unrelated to a post-procedural complication. Etiologies of perforation, leaks and fistula are listed in Table 1.

Surgical repair is often complex and associated with increased anesthesia risks and significant morbidity.¹ The clinical presentation varies with the size and location of the lesion. Fistula may involve communication between the intestinal tract and nearly any other location (entero-cutaneous, entero-atmospheric, entero-bronchial, entero-enteric, etc).² Common presenting symptoms include fever, pain, cough, malnourishment, and diarrhea.

• Perforation: Acute full thickness defect of the GI tract

• Leak: Disruption in a surgical anastomosis or closure resulting in fluid egress and accumulation

• Fistula: Abnormal communication between two epithelialized surfaces

The basic principles of fistula, perforation and leak management include identification of the site of the leak or fistula, drainage of leaked contents and disruption of the flow of intestinal fluids across the fistula or leak with diversion or closure. The decision between an endoscopic versus surgical approach depends on the size and chronicity of the leak or fistula, the location and endoscopic accessibility and the ability to drain associated contamination (Fig. 1). Endoscopic management requires diversion, closure, or a combination of both. A summary of currently available endoscopic tools for closure of GI leaks and fistulas is presented in Table 2.

Perforation/leaks associated with peritoneal contamination typically require surgical management. A multidisciplinary approach that includes surgery, interventional radiology and gastroenterology is required for these complex patients. A comprehensive approach to management that includes bowel rest, fluid and electrolyte management, nutritional support including total parenteral nutrition, antibiotic therapy and drainage of collections and abscesses, along with management of the primary site of leak, fistula or perforation is required. A recent case series demonstrated successful closure of full thickness intestinal perforation with associated peritoneal contamination managed with the OverStitch^TM endoscopic suturing device in 3 patients.³

Several endoscopic suturing devices have been described over the past decade, including the EndoCinch (C. R. Bard, Murray Hill, NJ, USA),^4–6 T-bars (Cook Medical, Bloomington, IN, USA),⁷ and Eagle Claw devices,⁸ but each had limitations that prevented widespread use.⁹ The OverStitch^TM (Apollo Endosurgery, Austin, TX, USA) is currently the only U.S. Food and Drug Administration-approved endoscopic suturing device. The current device overcomes many of the limitations of prior devices.¹⁰ It has been increasingly used to anchor stents within the GI lumen,¹¹ perform closure of perforations,¹¹ leaks, and fistulas, in addition to closure of mucosectomy after peroral endoscopic myotomy (POEM),^12,13 Natural Orifice Transluminal Endoscopic Surgery defect closures,¹⁴ and perform primary and revision bariatric procedures.^15,16 This review will focus on endoscopic suturing with the OverStitch^TM platform in the management of GI perforations, leaks and fistula.

The OverStitch^TM system is a disposable single-use, single operator, endoscopic suturing device that allows placement of running and interrupted full-thickness sutures using either permanent non-absorbable (2-0 and 3-0 polypropylene) or absorbable (2-0 and 3-0 polydioxanone) suture material. This device requires a double channel therapeutic endoscope.¹⁷

• 1. End cap

• 2. Needle driver

• 3. Needle driver handle

• 4. Anchor exchange catheter

• 5. Cinch device

• 6. Overtube

• 7. Helix cork screw catheter to assist with tissue apposition

The end cap of the OverStitch^TM device is mounted on the distal tip of the double channel endoscope. The end cap includes a suture arm which moves in an arc-like fashion, and the anchor exchange channel which approximates with the endoscopes therapeutic channel (Fig. 2).

The suture arm is connected and controlled by a hand lever which is attached near the endoscope channel ports. The suture material is attached to a pointed tissue anchor that is passed through the operating channel. Tissue approximation and suture placement may be facilitated by an optional tissue-retracting helix catheter or grasping forceps. After suturing is completed, a cinching device is utilized to secure the sutures. The OverStitch^TM Endoscopic Suturing System allows interrupted or continuous stitches without needing to remove the device (Fig. 3). The device can be reloaded with a new needle multiple times, without removing the endoscope.

Endoscopic suturing of perforations in the gastrointestinal tract

OverStitch^TM suturing has been shown in animal models to achieve good results in the closure of full thickness perforation.¹⁸ Rajan et al¹⁸ performed full-thickness gastric biopsy with gastric muscularis propria resection in twelve domestic pigs utilizing a submucosal endoscopy technique with the creation of a mucosal flap. The resultant offset mucosal entry site was closed with endoscopic suturing. At the end of 2 weeks, animals had a repeat endoscopy and necropsy which demonstrated the absence of ulceration at both the mucosal entry sites and the muscularis propria resection sites with complete healing of the serosa in all animals. Pauli et al¹⁹ demonstrated in a human (treat-and-resect) colon model in 4 patients undergoing elective colectomy with subsequent histologic examination of the endoscopic suturing results in post-colectomy specimen. They found that OverStitch^TM permitted safe and effective suturing at a sub-serosal depth without iatrogenic injury to adjacent structures. In addition, OverStitch^TM has been successfully utilized in the closure of iatrogenic endoscopic perforations (Fig. 4).²⁰

With widespread performance of endoscopic mucosal resection (EMR) and dissemination of endoscopic submucosal dissection (ESD), there is a need for additional minimally invasive methods to manage large iatrogenic perforations. Traditionally clips have been utilized.^21,22 A retrospective study of 12 patients showed that closure of large post-ESD defects with the OverStitch^TM endoscopic suturing device is technically feasible and can avoid hospitalization.¹² Twelve ESD sites with a mean size of 42.5 ± 14.8 mm, located in the colon, rectum, and stomach with perforation underwent immediate suturing repair. The mean suturing time was 10.0 ± 5.8 minutes and successful closure without additional complication was achieved in all patients.¹² OverStitch^TM case has also been utilized for the closure of full thickness esophagotomy defects which developed during POEM procedures.^13,23

Endoscopic suturing for the treatment of fistula and leaks

Successful closure of GI fistulae using endoscopic suturing (some after failed attempts with clips) and tissue adhesives has been reported over the past 5 years.^24–27 Fistula recurrence may develop following endoscopic suturing and additional data regarding long-term outcomes is needed. As with each intervention, careful selection of lesions for endoscopic therapy as part of a multidisciplinary team is required.²⁸ Epithelialized chronic fistula tracts may be very resistant to closure and be predisposed to recurrence after initial closure. Preparation of the tract with tissue cautery (often with argon plasma coagulation) at the perimeter of the fistula has been advocated. The fistula tract and edges may also be abraded with a brush to de-epithelialize the tissue, and promote tissue adherence. Running interrupted sutures are usually performed in two to three layers. Repeat treatment may be required.

With chronic fistulae, percutaneous catheters placed by radiology to drain the cavities/fluid collections are typically recommended. A technique utilizing a submucosal dissection and snare cautery to resect the fistulous tract, followed by closure, has been reported.²⁹

Occasionally after removal of a percutaneous endoscopic gastrostomy (PEG) tube, the stoma remains open, resulting in a gastrocutaneous fistula. Kantsevoy and Thuluvath²⁷ reported closure of such a fistula with OverStitch^TM endoscopic suturing. Subsequent reports detailed successful closure of widened PEG stoma.^24,26

Entero-bronchial fistula are notoriously difficult to close, and may require use of both enteric and bronchial stents. Catalano et al² reported successful closure in 6 patients, with 2 patients with endo-bronchial fistula requiring 3 to 4 sessions. All patients were able to resume oral feeding within 7 to 14 days. OverStitch^TM has also been used to close a chronic esophago-pleural fistula that developed due to Boerhaave syndrome.²⁵ Tuyama et al³⁰ retrospectively evaluated 11 patients which underwent full thickness suturing in comparison to 22 patients who had superficial suturing for endoscopic repair of gastro-gastric fistula after Roux-en-Y gastric bypass. OverStitch^TM full thickness suturing was found to be superior to suction based superficial suturing, with successful closure in 45% versus 22% of cases.

A retrospective multicenter case series of 122 patients undergoing endoscopic suturing for fully covered stent fixation, and/or direct therapy of perforation, fistula and leaks demonstrated an overall clinical success rate of 78.8% with a mean follow-up of 68 days. Forty patients underwent suturing for fistula closure with the majority at the site of gastrojejunal anastomosis. One-third of patients had prior unsuccessful therapy. Approximately one-half of patients underwent and an additional endoscopic therapeutic maneuver, with argon plasma coagulation (APC) ablation being the most common. Long term success was achieved in 80% of patients, with equally good results when suturing was performed as a rescue therapy. Long term success was more likely if the fistula was closed within 30 days of diagnosis (69% vs 23%; P = 0.037). In multivariate analysis, the only predictor of success among all cases was performance of suturing within 30 days of diagnosis (odds ratio, 4.1; 95% confidence interval, 1.26–13.2; P = 0.02). Fifteen patients underwent suturing, predominantly for closure of post-myotomy defects. Suturing was clinically successful in all cases except for the repair of a duodenal perforation. Twenty patients underwent suturing of anastamotic leaks after bariatric surgery (18 developing after performance of gastric sleeve), in conjunction with additional endoscopic therapy in the majority of cases (including APC, clipping, and stenting). The success rate for the treatment of anastomotic leaks was significantly lower, at 27%. Suturing for stent anchorage, most commonly in the esophagus, was performed in 47 patients, with an indication of leak or fistula in 26. Successful stent anchoring was achieved in 37 of 40 patients.¹¹

Advantages of OverStitch^TM relative to prior devices include the ability to reload suture material without removal of the endoscope from the patient, reliable depth of needle penetration and the ability to use tissue grasping accessories in the adjacent working channel. Some important limitations, however, persist. The current device is only compatible with double channel therapeutic endoscopes and passage through the oropharynx through an overtube is recommended. Ongoing challenges with the current version of the OverStitch^TM device include its large size, limited field of view and maneuverability. Suturing may be difficult or not possible in locations such as the gastric fundus, duodenum, and right colon.³¹

Therapeutic endoscopic tools and techniques for the treatment of intestinal perforations, leaks and fistulas include the application of tissue sealants, clip closure, and stent placement in addition to endoscopic suturing.^28,32 Hemoclips were created as a tool for endoscopic hemostasis and can provide mucosal; however, not full thickness tissue apposition. Over-the-scope clip (OTSC) are more robust devices and have been utilized for closure of perforation, leaks and fistulas, as reported in typically small case reports and series.^33–35 As noted above, given the difficulty in achieving clinical success, particularly with large and chronic fistula, leak and perforations, a combination of endoscopic therapeutic modalities may be utilized. There are limited comparative studies in patient cases between different techniques. A case control study comparing endoscopic suturing versus endoscopic clip closure of the esophageal mucosotomy at the conclusion of POEM procedures found both techniques to be equally safe and effective; however, closure time was shorter with clips (16 ± 12 minutes vs 33 ± 11 minutes; P = 0.044) with a trend towards lower cost with clips.³⁶ Stavropoulos et al³¹ retrospectively compared 25 POEM mucosotomy closures with clips and 25 with suturing. No difference was found in time (8.8 minutes [6–15 minutes] vs 10.1 minutes [5–16 minutes]) or cost.

Endoscopic suturing is an emerging technique in the management of GI perforations, leaks and fistula. Although the device requires directed training and is more complex to use than clips, it has the capability to mimic surgical closure in a minimally invasive way. Given the currently limited data, further prospective, comparative studies are needed to define the role of endoscopic suturing devices in the management of perforations, leaks and fistulas.