The over-the-scope clip system--a novel technique for gastrocutaneous fistula closure: the first North American experience.

BACKGROUND
The mainstay of therapy for gastrocutaneous (GC) fistulas has been surgical intervention. However, endoclips are currently used for management of perforations and fistulas but are limited by their ability to entrap and hold the tissue.


OBJECTIVE
To report the first North American experience with a commercially available over-the-scope clip (OTSC) device, a novel and new tool for the endoscopic entrapment of tissue for the closure of fistula and perforations.


METHODS
The present single-centre study was conducted at a tertiary referral academic gastroenterology unit and centre for advanced therapeutic endoscopy and involved patients referred for endoscopic treatment for the closure of a GC fistula. The OTSC device was mounted on the tip of the endoscope and passed into the stomach to the level of the fistula. The targeted site of the fistula was grasped with the tissue anchoring tripod and pulled into the cap with concomitant scope channel suction. Once the tissue was trapped in the cap, a 'bear claw' clip was deployed.


RESULTS
The patients recovered with fistula closure. No complication or recurrence was noted. Fistula sizes >1 cm, however, were difficult to close with the OTSC system. The length of stay of the bear claw clip at the fistula site is unpredictable, which may lead to incomplete closure of the fistula.


CONCLUSION
Closure of a GC fistula using a novel 'bear claw' clip system is feasible and safe.

T he mainstay of therapy for gastrocutaneous (GC) fistulas has been surgical intervention (1). However, a conservative endoscopic approach has recently been preferred, with the advantages of negligible morbidity and mortality, a short hospital stay and the possibility of prompt resumption of an oral diet (2). Routine endoscopic methods to close gastrointestinal (GI) fistulas include stents, injectables, stitch devices and endoclips (Table 1); however, endoclips are currently used for management of perforations and fistulas but are limited by their ability to entrap and hold the tissue. The Over the Scope Clip (OTSC, Ovesco AG, Germany) system is a new tool for the endoscopic entrapment of tissue. Indications for its use are hemostasis, compression of large vessels, and closure of leaks or fistulas of the GI tract. Preclinical work has shown the device to be feasible and safe for the closure of gastric, duodenal and colonic perforations up to 20 mm in diameter (1,2). In the past three years (Table 2), several reports from Europe have attested to the efficacy of this device, but to date, there is no published North American experience. We present a case of an iatrogenic fistula successfully treated with the OTSC system.

Patient
The procedure was performed at Lenox Hill Hospital, New York (USA). Informed written consent was obtained from the patient. An 80-year-old woman with a medical history including hypertension, aortic valve regurgitation and replacement, anemia and bacteremia presented with a longstanding GC fistula. The patient had originally undergone a transesophageal echocardiogram, which resulted in an esophageal perforation. Postsurgical repair included the placement of a feeding jejunostomy tube and venting gastrostomy tube. Subsequently, the patient was able to tolerate oral feeding. After removal of both the jejunostomy and gastrostomy tubes, the GC fistula persistently drained for nine months despite maximal acid suppression. Her course was complicated by persistent iron deficiency anemia, which required transfusions of intravenous dextran and packed red blood cells. The patient presented to the clinic as an outpatient for evaluation of endoscopic closure of the fistula. It was then decided the patient would be an excellent candidate for the OTSC system. BACKGrouNd: The mainstay of therapy for gastrocutaneous (GC) fistulas has been surgical intervention. However, endoclips are currently used for management of perforations and fistulas but are limited by their ability to entrap and hold the tissue. oBJeCtive: To report the first North American experience with a commercially available over-the-scope clip (OTSC) device, a novel and new tool for the endoscopic entrapment of tissue for the closure of fistula and perforations. Methods: The present single-centre study was conducted at a tertiary referral academic gastroenterology unit and centre for advanced therapeutic endoscopy and involved patients referred for endoscopic treatment for the closure of a GC fistula. The OTSC device was mounted on the tip of the endoscope and passed into the stomach to the level of the fistula. The targeted site of the fistula was grasped with the tissue anchoring tripod and pulled into the cap with concomitant scope channel suction. Once the tissue was trapped in the cap, a 'bear claw' clip was deployed. results: The patients recovered with fistula closure. No complication or recurrence was noted. Fistula sizes >1 cm, however, were difficult to close with the OTSC system. The length of stay of the bear claw clip at the fistula site is unpredictable, which may lead to incomplete closure of the fistula. CoNClusioN: Closure of a GC fistula using a novel 'bear claw' clip system is feasible and safe. MÉthodoloGie : Les chercheurs ont mené la présente étude monocentrique dans une unité de gastroentérologie universitaire de soins tertiaires et un centre d'endoscopie thérapeutique avancée, auprès de patients aiguillés afin de subir un traitement endoscopique pour fermer une fistule GC. L'agrafe sur endoscope était fixée à l'extrémité de l'endoscope et insérée dans l'estomac jusqu'à la fistule. Le foyer ciblé de la fistule était saisi au moyen du trépied d'ancrage de tissu et tiré dans le capuchon par aspiration concomitante par voie endoscopique. Une fois les tissus piégés dans le capuchon, une agrafe « en patte d'ours » était déployée. rÉsultAts : Les patients se sont rétablis de la fermeture de la fistule, sans complication ni récurrence. Les fistules de plus de 1 cm étaient toutefois difficiles à fermer au moyen de l'agrafe sur endoscope. La durée du maintien de l'agrafe en patte d'ours au foyer de la fistule est imprévisible, ce qui peut susciter une fermeture incomplète de la fistule. CoNClusioN : Il est faisable et sécuritaire de fermer une fistule GC au moyen d'un nouveau système d'agrafe « en patte d'ours ». scan with oral contrast revealed a moderate hiatal hernia, pleural thickening consistent with previous perforation, empyema as well as contrast extravasation through the GC fistula.

Bear claw technique
The OTSC system is composed of an application cap, which is mounted onto the distal tip of an endoscope and a connected releasing mechanism installed on the handle of the scope. Three different variants of the clip consisting of a shape-memory alloy (nitinol) are available: the 'traumatic'; the 'atraumatic'; and the gastric fistula closure (Figure 1). In contrast to common endoscopic clips, the OTSC is able to compress larger quantities of tissue. There are two proprietary devices to draw the tissue into the cap: a dual arm forceps and a tissue anchoring tripod. The clip is deployed by a string release fixed to a rotating wheel attached to the accessory channel.
The single-channel endoscope (Olympus Medical Systems, USA) was introduced through the mouth and advanced down to the level of a hiatal hernia sac where previously placed surgical sutures from the esophageal perforation were seen adjacent to the gastroesophageal junction. The lesser curvature revealed normal findings, whereas the greater curvature revealed a retracted mucosal surface at the proximal body in continuity with the gastrostomy site on the anterior abdominal wall. A Savary guide wire was advanced through the skin opening of the GC fistula through the abdominal wall and into the stomach (Figure 2). The OTSC system was mounted on the tip of the scope and passed down into the stomach to the level of the fistula. The targeted site of the fistula was grasped with the tissue-anchoring tripod and pulled into the cap with concomitant scope channel suction. Once the tissue was trapped in the cap, the bear claw clip was deployed.
There was a small recessed area immediately adjacent to the released bear claw. Because it was uncertain as to whether this represented a corner of the fistulous opening and to ensure the closure of the first clip, a second bear claw clip was deployed in the left aspect of the previously placed bear claw (Figure 3). The Savary wire was then used to probe the fistulous tract from the skin into the stomach but could not be passed with the bear claw clips in position.

results
The patient was discharged home on ciprofloxacin and metronidazole for one week. At the three-month follow-up, the area of the previous GC fistula had healed entirely (Figure 4). A metallic object was seen in a pool of retained food debris in the stomach. A Roth net was used to grab the object, which appeared to be two retained bear claws. After the scope was withdrawn, it was apparent that the two original bear claw clips, which were deployed three months earlier, were stacked together.   (6), nine patients with bleeding and/or perforations of the GI tract were treated with the OTSC system. In 12 consecutive patients, Manta et al (7) found that placement of 9.5 mm or 10.5 mm OTSC led to fistula healing, and was confirmed by endoscopic and radiological methods. In this system, the bear claw clip failed only once and no complications of the OTSC were noted. A study by von Renteln et al (8) demonstrated the limitations of the OTSC system with unsuccessful placement of two clips in two successive patients. The initial closure attempts in one esophagopulmonary fistula and one jejunocutaneous fistula using OTSCs were not successful because of chronic fibrotic changes and scarring at the fistula site. Severe fibrosis and scarring may limit the ability to draw tissue into the applicator cap, precluding successful OTSC deployment and feasibility.
In an attempt to treat failed gastrojejunal bypass in 2010, Heylen et al (9) also demonstrated that the OTSC system can be effective in maintaining the Fobi pouch (combination of stomach reduction and gastric bypass), aiding in additional weight loss. An OTSC was applied to narrow the pouch outlet in 94 patients following gastric bypass after unintended weight gain due to dilation of the gastrojejunostomy anastomosis. At the time of OTSC application, the mean (± SD) body mass index was 29.7±1.8 kg/m 2 compared with 27.4±3.8 kg/m 2 at a mean follow-up of 352±66 days. Additionally, Iacopini et al (10) demonstrated that the OTSC system could be applied to close fistulas subsequent to gastric band erosion and penetration. After placement, the external fistula closed and both OTSCs were lost spontaneously after four weeks (11).

CoNClusioN
The results from several studies (1-3,12) and our case demonstrate the efficacy of the OTSC system in the closure of the GC fistula.  The significance of the OTSC system is its nonsurgical approach. The most important concept is the resultant outcome without complications. This device can be used for closure of GC fistula, GI leaks, enterocutaneous fistula, rectovaginal fistula, etc.