Abstract
Objectives:
The Over-The-Scope-Clip (OTSC) has had an evolving role in endoscopic closure of gastrointestinal wall defects, in hemostasis of primary or postinterventional bleeding, and approximation of postbariatric surgery defects. Rapid and effective closure of gastrocutaneous (GC) fistulae using this device has been recently described in the literature. The aim of this study was to evaluate the technical feasibility, efficacy and safety of OTSC as an effective tool in the management of persistent GC fistulae secondary to a complication of percutaneous endoscopic gastrostomy (PEG) tube placement.
Method:
In this multicenter prospective observational study, we describe our experience with OTSC in the closure of persistent GC fistulas secondary to PEG tube placement. Patients with GC fistulas were sequentially enrolled with a mean age of 84 years. Primary treatment outcome was the immediate successful closure of GC fistula and resolution of leak. Secondary outcome was no recurrence of the fistula and leaks on follow up.
Results:
A total of 10 patients were enrolled over the study period. Mean age was 84.4 ± 8.75 years. The primary treatment outcome was achieved in all the patients undergoing this intervention. Secondary outcome was observed in 9/10 (90%) subjects. No procedural complications were reported. Larger fistulae (>2.5 cm) and those with significant fibrosis were more difficult to close with the OTSC system. The mean follow-up time after OTSC application was 43.7 ± 20.57 days. A limitation of this study was that there was no control group.
Conclusions:
OTSC application is a safe and effective endoscopic approach for the closure of persistent GC fistulae secondary to a complication of PEG tube placement.
Introduction
Chronic nonhealing gastrocutaneous (GC) fistulas have traditionally been managed surgically [Schurr et al. 2008]. The development of endoscopic closure devices such as over-the-scope-clips (OTSCs) has made endoscopic management of gastrointestinal tract fistulas (GIF) feasible. These nonsurgical approaches have a lower complication rate, shorten the hospital stay and facilitate the prompt resumption of an oral diet [Voermans et al. 2009]. Several endoscopic methods to close GIF have been described including stents, injectables, stitch devices and endoclips with variable success [Kumar and Thompson, 2013]. Although hemostatic endoclips have been used for management of perforations and fistulae, their efficacy has been limited by the inability to trap and hold adequate tissue.
The ‘bear claw’ or Over-The-Scope-Clip (OTSC®) system (Ovesco Endoscopy GmbH, Tubingen, Germany) has shown a promising role in the closure of iatrogenic full-thickness perforations, large bleeding tumors, hemostasis of primary or postinterventional bleeding, and approximation of postbariatric surgical defects [Singhal et al. 2013; Kirschniak et al. 2007; Baron et al. 2012]. Currently available literature has shown the device to be a technically feasible and safe approach for the closure of gastric, duodenal and colonic perforations up to 18 mm in diameter [Schurr et al. 2008; Voermans et al. 2009; Arezzo et al. 2009; von Renteln et al. 2009]. Case reports have described the device to be feasible and safe for the closure of GC fistulae [Kouklakis et al. 2011; von Renteln et al. 2010; Turner et al. 2010; Sandmann et al. 2011].
In this case series, we tabulate our experience with the OTSC system and describe its technical feasibility, efficacy and safety as an effective tool in the endoscopic closure of GC fistulae secondary to percutaneous endoscopic gastrostomy (PEG) placement. Our study is the largest case series available in current literature to evaluate this therapeutic modality in this specific clinical setting.
Methods
This is a multicenter prospective observational study which was conducted between January 2012 and January 2013. Subjects with chronic GC fistula after PEG tube placement who had failed to respond to conservative medical management were included. Conservative medical management included nothing by mouth, acid suppression and antibiotics (if indicated) for at least 1 week. Exclusion criteria included pregnancy, patients less than 18 years of age and lack of informed consent. In all the subjects, written informed consent was obtained from the legal representative permitting the endoscopic procedure with application of OTSC. Demographic data including age and sex were included in the study table. Primary treatment outcome of successful closure was defined as a satisfactory application of the OTSC system on the target site and/or resolution of leakage confirmed by leak test. Failure was defined as unsatisfactory application of the OTSC and/or failure of resolution of leakage. All general procedural complications and specific OTSC application related complications were noted. Subjects who had a successful primary outcome were followed for a mean of 43 days to determine if the secondary outcome of long-term successful closure was achieved.
OTSC® system
The OTSC® system is made of a nitinol alloy, which allows a high grade of elasticity [von Renteln et al. 2010]. It consists of an applicator cap with a premounted clip, a thread attached to the clip to guide release and a hand wheel for clip deployment (Figure 1). Different clip designs are available for specific indications. Type ‘a’ with a round tooth appearance (baby bear) is mostly used for hemostasis. Type ‘t’ with a pointed tooth appearance (mamma bear) is mostly used for closure of perforations. Type ‘gc’ with a long pointed tooth appearance (papa bear) is the preferred choice for closure of fistulae and larger perforations of the upper gastrointestinal tract. The standard method for loading and deploying the OTSC was described by us previously [Singhal et al. 2014]. The hand wheel is mounted on the working side channel of the endoscope and attached to the preloaded applicator cap by a thread passing through the channel. A twin grasper or simple suctioning is used to approximate the tissue edges prior to deployment and the clip is deployed by turning the hand wheel.

The Over-the-Scope-Clip system. Left: Clip mounted on an applicator cap with thread attached to assist release. Right: Arrow indicates the device used to pull the thread through the working channel of endoscope. Triangle indicates the hand wheel for clip release.
Results
A total of 10 subjects met the inclusion criteria and were enrolled in this prospective observational study. Mean age was 84.4 ± 8.75 years. Subject details of age, sex, indication and outcome are shown in Table 1. The mean diameter of the GC fistula was 13.7 mm (range = 6–20 mm).This was measured by comparison with a foreign body retrieval grasper (diameter of 6 mm in an open position). All the subjects had failed to respond to conservative management which included nothing by mouth, acid suppression, antibiotics, nutrition and intensive care. Primary treatment outcome of successful closure defined as a satisfactory application of the OTSC system on the target site and/or resolution of leakage confirmed by leak test was achieved in all 10 subjects (100%) (Table 1). Secondary outcome defined as no recurrence of the fistula and leaks on mean follow up of 43 days was observed in nine out of 10 subjects (90%) (Table 1).
Demographics and results.
F, female; M, male; GC, gastrocutaneous; PEG, percutaneous endoscopic gastrostomy; OTSC, Over-The-Scope-Clip.
A single OTSC was applied in all cases, except for Case 10 where a second clip was successfully applied to a second site adjacent to the original closure site. An Ovesco Clip 12/6 t-type clip was used in all 10 subjects. There were no complications related to endoscopy, sedation or application of the clipping device. There were no device malfunctions. The deployment data are shown in Figure 2.

(a) External view of the gastrocutaneous fistula. (b) Endoscopic view of the defect causing leakage, which was 10 mm in diameter. (c) The grasped tissue is pulled into the transparent OTSC applicator cap which carries the clip. (d) Gastrocutaneous fistula closure immediately after OTSC clip application.
One case did not have a successful secondary outcome of long-term closure (Case 2). The primary outcome was achieved with satisfactory application of the OTSC and immediate leak resolution. Follow up showed that the leak had restarted and further imaging studies showed an enlarged fistula measuring around 30 mm. This was successfully repaired with traditional surgical intervention.
All subjects were followed for the secondary outcome goal and for any other complication or device failure. The mean follow-up time after the OTSC application was 43.7 ± 20.57 days.
Discussion
The OTSC system is rapidly evolving to give the gastroenterologist a simple to use, safe and effective tool. The application of this technology is expanding and includes closure of defects (fistulae, perforations, leaks) and control of bleeding from large vessels and tumors. Initial experience suggests that the OTSC is superior to conventional through-the-scope-clips (TTSCs) in situations where closure of larger defects is needed [Singhal et al. 2013]. The OTSC system does not appear to have a sharp learning curve and is easy to use, with a technique similar to band ligation which has been in use for decades.
GC fistulae are seen as complications of PEG and bariatric surgery [Papavramidis et al. 2004; Shellito and Malt, 1985]. Conservative management strategies include gastric acid inhibition, bowel rest, control of infection with local or systemic antibiotics, gastric decompression and drainage of local collections [Papavramidis et al. 2004]. Due to persistent irritation from gastric secretions, GC fistulae are difficult to close with conservative management and can lead to local cellulitis and sepsis with significant mortality [Rolandelli and Roslyn, 1996].
All the subjects in our study had persistent GC fistulas from a prior PEG placement. Poor wound healing in elderly subjects with co morbidities resulted in stomal enlargement and leakage with chemical dermatitis and cellulitis. Endoscopic methods have been previously described for the treatment of chronic GC fistulas including electrical and chemical cauterization, fibrin glue sealant, endoscopic clipping using TTSC and suturing with variable success [Papavramidis et al. 2004; Eskaros et al. 2009; Merrifield et al. 2006; Hameed et al. 2009] and biological glue has shown limited success in fistula closure [Papavramidis et al. 2004; García Moreno et al. 2007; Ramón Rábago et al. 2006]. We have successfully used endoscopic suturing modifying a technique first reported by Alberti-Flor [Eskaros et al. 2009; Alberti-Flor, 2002] and have had some success using combined chemical/electric cautery and TTSC [Duddempudi et al. 2009]. A recent study described a novel tissue apposition system (TAS) for the closure of a gastrogastric fistula in four patients with limited long-term success [Spaun et al. 2010].
OTSC has been reported to be successful for closure of tracheoesophageal fistula and gastric fistulas as a complication of bariatric procedures [Repici et al. 2009; Traina et al. 2010; Conio et al. 2010; Iacopini et al. 2010; Mercky et al. 2015]. The claw design and ability to approximate tissue to achieve closure makes the OTSC system a good tool in addressing the vexing issue of chronic GC fistulae secondary to PEG tube related complications In this case series, the results were excellent with the primary outcome of immediate closure achieved in all cases and secondary outcome of long-term closure achieved in 90% of the cases. There are some limitations and technical difficulties in the placement of OTSC [Changela et al. 2014], with angulation and fibrosis at the fistula site causing operational difficulty. It is important to ensure that the deployment is performed only after optimal positioning and alignment. An improperly placed clip will interfere with subsequent attempts to correct the problem. The use of assistive devices like the twin grasper and anchor available with the OTSC system can be helpful in certain situations.
Conclusion
This case series gives the gastroenterologist an additional tool in the treatment of a vexing problem. The OTSC system appears to be a safe, easy to use and effective tool to treat persistent post PEG GC fistulae, which have not responded to medical management. This procedure can be performed as an outpatient. It is likely to be less expensive than conventional surgery and can shorten or eliminate the hospital stay. Although this is the largest case series of post PEG GC closures, it still had a limited number of subjects. Multicenter trials with a larger number of subjects will be required to validate this approach as standard therapy.
Footnotes
Conflict of interest statement
The authors declare no conflicts of interest in preparing this article.
Funding
This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
