Closure methods for large defects after gastrointestinal endoscopic submucosal dissection.

Nowadays, endoscopic submucosal dissection (ESD) is commonly performed for the removal of large gastrointestinal lesions. Endoscopic mucosal defect closure after ESD is vital to avoid adverse events. In recent years, many innovative instruments have emerged and proved to be beneficial. In this paper, we conducted a thorough literature review and summarized the closure methods for large-size post-ESD mucosal defects over decades. We separated these methods into five categories based on the operational principle: "side closure" method, "ring closure" method, "layered closure" method, "hand suturing closure" method, and "specially designed device closure" method. Side closure with clips assisted by instruments such as threads or loops is applicable for each segment of the gastrointestinal tract to prevent postoperative bleeding. If the defect tension is too large to close with the traditional side closure methods, zigzag closure and ring closure could be applied to gather the bilateral defect edges together and achieve continuous closure. In the stomach and rectum with a high risk of submucosal dead space between the submucosa and muscular layers, side closure methods with muscle layer grasping clip or layered closure methods could enable the involvement of the deep submucosa and muscle layers. The ring closure method and specially designed devices including over-the-scope clip, Overstitch, and X-tack could resolve perforation effectively. Individual closure method requires endoscope reinsertion or sophisticated operation, which may be limited by the deep location and the narrow lumen, respectively. Although specially designed devices are expected to offer promising prospectives, the cost-effectiveness remains to be a problem.

Assessment and Techniques for Endoscopic Closure.

Endoscopic closure is an essential technique to perform safe advanced endoscopy. Without appropriate closure of a defect, patients can experience spillage of fecal contents into the peritoneal cavity resulting in abdominal sepsis. The essential components to performing endoscopic closure are assessing the defect appropriately and choosing the correct closure technique. Assessing the defect involves five separate elements: timing, size, depth, shape, blood flow, and location in the colon or rectum. Understanding how each of these elements contributes toward a successful closure allows an endoscopist to choose the proper technique for closure. There have been many types of closure techniques described in the literature but the most common are through the scope clips, over the scope clips, and endoscopic suturing. There are advantages and disadvantages of each of these closure techniques. In this manuscript, we will discuss these common techniques as well as some additional techniques and the situations where they can be employed.

Comparison of purse-string suture versus over-the-scope clip for gastric endoscopic full-thickness closure: traction and leak pressure testing in ex vivo porcine model.

BACKGROUND: The recently developed endoscopic full-thickness resection technique requires reliable closure. The main closure methods are the purse-string suture (PSS) technique and over-the-scope clip (OTSC) technique; however, basic data on the closure strength of each technique are lacking. This study was performed to compare the closure strengths of these two methods in an ex vivo porcine model. METHODS: In the traction test, a virtual 5-cm full-thickness closure line was closed by the following six methods three times each: conventional hemoclips, mucosal PSS, seromuscular PSS, mucosal OTSC, seromuscular OTSC, and surgical suture. The primary endpoint was the tension at the starting point of dehiscence, measured in Newtons (N) by an automatic traction machine. In the leak test, a 15-mm gastric full-thickness defect was closed by PSS or OTSC six times each, and the closed stomach was then pressurized in a water container. The primary endpoint was the leak pressure when air bubbles appeared. The secondary endpoints were the procedure time and presence of complete inverted closure. RESULTS: The mean tension was 2.16, 3.68, 5.15, 18.30, 19.30, and 62.40 N for conventional hemoclips, mucosal PSS, seromuscular PSS, mucosal OTSC, seromuscular OTSC, and surgical suture, respectively. Complete inverted closure was observed for seromuscular PSS, seromuscular OTSC, and surgical suture. The mean leak pressure was 13.7 and 24.8 mmHg in the PSS and OTSC group, respectively (P < 0.01). The mean procedure time was 541 and 169 s in the PSS and OTSC group, respectively (P < 0.01). Complete inverted closure was observed in OTSC alone. CONCLUSION: The OTSC, which allows complete inverted closure, showed greater closure strength than PSS. Considering the size limitation suitable for single OTSC, a therapeutic strategy for closing the larger size is further warranted.

Suturing techniques with endoscopic clips and special devices after endoscopic resection.

Endoscopic submucosal dissection is an established method for complete resection of large and early gastrointestinal tumors. However, methods to reduce bleeding, perforation, and other adverse events after endoscopic resection (ER) have not yet been defined. Mucosal defect closure is often performed endoscopically with a clip. Recently, reopenable clips and large-teeth clips have also been developed. The over-the-scope clip enables complete defect closure by withdrawing the endoscope once and attaching the clip. Other methods involve attaching the clip-line or a ring with an anchor to appose the edges of the mucosal defect, followed by the use of an additional clip for defect closure. Since clips are limited by their grasping force and size, other methods, such as endoloop closure, endoscopic ligation with O-ring closure, and the reopenable clip over-the-line method, have been developed. In recent years, techniques often utilized for full-thickness ER of submucosal tumors have been widely used in full-thickness defect closure. Specialized devices and techniques for defect closure have also been developed, including the curved needle and line, stitches, and an endoscopic tack and suture device. These clips and suture devices are applied for defect closure in emergency endoscopy, accidental perforations, and acute and chronic fistulas. Although endoscopic defect closure with clips has a high success rate, endoscopists need to simplify and promote endoscopic closure techniques to prevent adverse events after ER.

What's New with Endoscopic Treatments for Early Gastric Cancer in the "Post-ESD Era"?

BACKGROUND: Endoscopic treatments for gastric cancers have still been progressing even after the great success of endoscopic submucosal dissection (ESD). SUMMARY: In further advancements of ESD, safe and less-invasive procedures are challenged by managing postoperative bleeding, one of the major adverse events in ESD. Covering the mucosal defect after removal of lesions appears reasonable and effective for preventing delayed bleeding from the post-ESD ulcers. Shielding with biodegradable sheets is attempted on clinical trials, which show equivocal results. Although suturing of the mucosal rims is technically challenging, pilot studies demonstrate favorable outcomes for avoiding post-ESD bleeding even in cases at high risk. In cases after noncurative resection of ESD, the selection of patients who truly require additional gastrectomy with lymph node dissection is important to provide necessary surgery. Risk stratification of lymph node metastases and surgery has been developed, which offers tailor-made management to each patient considering the risks and benefits. In surgery, function-preserving gastrectomy to minimize the resection area in both lymphadenectomy and the primary site is clinically introduced. The sentinel node navigation surgery is promising to realize the minimally invasive gastrectomy, and it should strongly fit ESD as well as laparoscopic endoscopic cooperative surgery or endoscopic full-thickness resection, although nonexposure approaches are desirable. Key Message: Development for less-invasive managements on gastric cancer will be continued in step with the advancement of endoscopic treatments.

Closure of gastric perforations during endoluminal resection using a novel biodegradable collagen sol: A feasibility survival study on porcine model (with video).

OBJECTIVE: A prior study using porcine colon demonstrated the feasibility of a novel injectable, temperature?responsive, and biodegradable collagen sol (ICS) that transforms from a liquid to a gel state in response to body temperature for endoscopic closure of perforation during endoscopic resection (ER). This study aims to report the acute and survival outcomes of ICS for gastric perforations during ER. METHODS: In two experiments using nine live pigs under general anesthesia, four and six perforations (3-5\xA0mm) were created using an electrosurgical knife in acute and survival experiments, respectively. ICS was delivered to the perforations using an endoscopic catheter. In Experiment 1, a leak test and histopathology were performed on all explanted stomachs after euthanization. In Experiment 2, perforation sites were assessed by gastroscopy and histopathology 7, 14 and 28\xA0days post? RESULTS: In Experiment 1, gastroscopy confirmed complete closure of the perforations with ICS and no evidence of leak. Subsequent histopathology revealed a fixation of collagen gel (CG) as a sealant agent at the perforation sites. There were no adverse effects related with ESD or the use of ICS. In Experiment 2, histopathology revealed a fixation of CG as a sealant agent, replacement with granulation tissue and no CG; and fibrotic tissue at 7, 14 and 28\xA0days, respectively. CONCLUSIONS: This study presents a novel method using ICS, demonstrating promising efficacy and safety profile for endoscopic closure of perforations during ER. Further studies are necessary before translating to clinical use.

Novel temperature-responsive, biodegradable and injectable collagen sol for the endoscopic closure of colonic perforation holes: Animal study (with videos).

OBJECTIVES: Endoscopic submucosal dissection (ESD) poses a risk of intraprocedural perforation. We have developed a biodegradable injectable collagen sol that undergoes a liquid-to-gel formation in response to body temperature. Here, we investigated the feasibility of this novel collagen sol for the endoscopic closure of iatrogenic perforation holes. METHODS: In two experiments, 12 and 5 colonic perforation holes (3-5 mm) were made using an ESD knife in four and three live pigs under general anesthesia, respectively. In Experiment 1, collagen sol was delivered to the perforation holes using an endoscopic catheter. When the colon was expanded by CO2 insufflation, endo-clips were applied to the perforation holes. For Experiment 2, Collagen sol adjusted based on the Experiment 1 results was delivered to the perforation holes in the same manner. A leak test was performed for every colon after the pigs were killed, and the histology of the perforation sites was evaluated. RESULTS: In both experiments, collagen sol was smoothly delivered to the target area and fixed as a gel on the perforation holes. Experiment 1, 83% (10/12) of the perforation holes were completely closed, and all endo-clips were placed with composure. Experiment 2, all perforation holes were completely closed with collagen gel. There was no leak from the perforation holes. Histology revealed a fixation of the collagen gel as an embolus agent in the perforation holes. CONCLUSIONS: This novel collagen sol may be used for the endoscopic closure of intraprocedural perforation. Further studies will determine this collagen sol's clinical feasibility and safety.

Effect of prophylactic closure on adverse events after colorectal endoscopic submucosal dissection: A meta-analysis.

BACKGROUND AND AIM: Endoscopic submucosal dissection (ESD) has a high en bloc resection rate and is widely performed for large colorectal lesions. However, colorectal ESD is associated with a high frequency of adverse events (AEs), and the efficacy of prophylactic endoscopic closure after ESD for preventing AEs is still controversial. This meta-analysis was conducted to assess the efficacy of closure on AEs following colorectal ESD. METHODS: We searched PubMed, Embase, and the Cochrane Library for eligible studies. The chi-square-based Q statistics and the I2 test were used to test for heterogeneity. Pooling was conducted using a fixed or random effects model. RESULTS: We identified eight eligible studies that compared the effects of closure vs non-closure with respect to delayed bleeding, delayed perforation, and post-ESD coagulation syndrome. Compared with non-closure (5.2%), closure was associated with a lower incidence (0.9%) of delayed bleeding (pooled odd ratios [ORs]:0.19, 95% CI: 0.08-0.49) following ESD. The pooled ORs showed no significant differences in incidence of delayed perforation (pooled OR: 0.22; 95% CI: 0.05-1.03) or post-ESD coagulation syndrome (pooled OR:0.75; 95% CI: 0.26-2.18) between the closure and non-closure groups. CONCLUSION: Prophylactic endoscopic closure may reduce the incidence of delayed bleeding following ESD of colorectal lesions. Future studies are needed to further illuminate risk factors and stratify high risk subjects for a cost-effective preventive strategy.

Over-the-scope clip system: A review of 1517 cases over 9 years.

Rescue therapy for gastrointestinal (GI) refractory bleeding, perforation, and fistula has traditionally required surgical interventions owing to the limited performance of conventional endoscopic instruments and techniques. An innovative clipping system, the over-the-scope clip (OTSC), may play an important role in rescue therapy. This innovative device is proposed as the final option in endoscopic treatment. The device presents several advantages including having a powerful sewing force for closure of GI defects using a simple mechanism and also having an innovative feature, whereby a large defect and fistula can be sealed using accessory forceps. Consequently, it is able to provide outstanding clinical effects for rescue therapy. This review clarifies the current status and limitations of OTSC according to different indications of GI refractory disease, including refractory bleeding, perforation, fistula, and anastomotic dehiscence. An extensive literature search identified studies reported 10 or more cases in which the OTSC system was applied. A total of 1517 cases described in 30 articles between 2010 and 2018 were retrieved. The clinical success rates and complications were calculated overall and for each indication. The average clinical success rate was 78% (n = 1517) overall, 85% for bleeding (n = 559), 85% (n = 351) for perforation, 52% (n = 388) for fistula, 66% (n = 97) for anastomotic dehiscence, and 95% (n = 122) for other conditions, respectively. The overall and severe OTSC-associated complications were 1.7% (n = 23) and 0.59% (n = 9), respectively. This review concludes that the OTSC system may serve as a safe and productive device for GI refractory diseases, albeit with limited success for fistula.

Over-the-scope-clip applications for perforated peptic ulcer.

AIM: To investigate the effectiveness of over-the-scope-clip (OTSC)-based endoscopic closure in patients with perforated peptic ulcer (PPU). METHODS: One hundred six patients diagnosed with PPU were treated with either OTSC (n = 26) or conservative treatments (n = 80), respectively. The outcome assessments included technical success rate, clinical success rate, post-treatment complications after 1 month, mortality rate, time to resume oral feeding, length of hospital stay, and the administration of antibiotics. RESULTS: In the OTSC group, technical and clinical success was achieved in 100% of patients without any complications, including death, incomplete closure, duodenal obstruction, and gastrointestinal bleeding, with a median operation time of 10 min. All patients in the OTSC group were discharged, while the mortality rate in the control group was 13.8%. Subsequent surgeries were required in 30% of patients in the control group. The median times to resume oral feeding were 3.5 (interquartile range [IQR] 2.0-5.25) days in the OTSC group and 7.0 (IQR 5.0-9.0) days in the control group (p < 0.001). One month post-procedure, 30% (24/80) of patients in the control group and 0 (0/26) in the OTSC group required additional operations (p < 0.001). No significant difference was found in the length of the hospital stay and the administration of antibiotics between the two groups (p > 0.05). CONCLUSIONS: OTSC-based endoscopic technique, with a high clinical success rate and a shorter time to resume oral feeding, was effective in achieving closure of PPU with a diameter < 15 mm.

Endoscopic technique for closure of enterocutaneous fistulas.

BACKGROUND AND OBJECTIVES: Endoscopic over the scope clip (OTSC) closure represents a new technique for endoscopic management of enteric bleeding and tissue defects such as anastomotic leaks and enterocutaneous (EC) fistulas. We aim to describe our technical approach for OTSC closure of EC fistulas and convey our outcomes. METHODS AND PROCEDURES: This retrospective review includes ten patients who underwent OTSC application for EC fistulas by surgical endoscopists at a US tertiary care hospital from July 2015 to October 2017. Demographic data, along with type of defect, location, duration of lesion, success or failure of OTSC, and nutritional status were compiled. The ACS NSQIP surgical risk calculator was used to project the risk of mortality, complications, length of stay, and risk of readmission had our patients undergone surgical correction of their fistula. RESULTS: Overall success for EC fistula closure was 70%. Acute fistulas were closed with a success rate of 86%. Chronic fistulas were closed successfully in only 33% of cases. Of patients successfully closed, NSQIP-predicted rates of mortality, any complication, and median length of stay were 21.1%, 34.5%, and 9.5 days, respectively. With OTSC, these patients experienced 0 mortalities, 0 complications, and had a median length of stay of 4 days. CONCLUSION: OTSC is an effective adjunctive measure to improving rates of successful closure of EC fistulas and compromised anastomosis. OTSC conveys a markedly improved procedural risk profile as compared to standard surgical correction.

A novel grasp-and-loop closure method for defect closure after endoscopic full-thickness resection (with video).

BACKGROUND: Endoscopic full-thickness resection (EFTR) is a minimally invasive method for en bloc resection of gastrointestinal (GI) lesions originating from the muscularis propria layer. Successful closure of the wall defect is a critical step. OBJECTIVE: The aim of this study was to evaluate the feasibility and efficacy of a novel and simplified endoscopic grasp-and-loop (GAL) closure method using an endo-loop assisted with grasping forceps for defect closure. METHODS: From January 2015 to March 2016, 13 patients with submucosal tumors (SMTs) originating from the muscularis propria (MP) layer underwent EFTR and were enrolled in this study. After successful tumor resection, an endo-loop was anchored onto the circumferential margin of the gastric defect with grasping forceps assistance and tightened gently. Patient characteristics, tumor size, en bloc resection, and postoperative complications were evaluated. RESULTS: Of the 13 lesions in the stomach, two were located in the greater curvature of the mid-upper body, 11 were located in the fundus. The endoscopic GAL closure method was successfully performed after EFTR in all the 13 patients without laparoscopic assistance. The mean procedure time was 43.5 min (range 20-80 min), while the GAL closure procedure took a mean of 9.4 min (range 3-18 min). The mean resected lesion size was 1.5 cm (range 0.5-3.5 cm). Pathological diagnoses of these lesions were 11 gastrointestinal stromal tumors (GISTs) and two leiomyomas. No major adverse events occurred during or after the procedure. All the patients were discharged after a mean time of 2.4 days (range 1-4 days). No residual lesion or tumor recurrence was found during the follow-up period (median, 5 months; range, 1-15 months). CONCLUSIONS: The endoscopic GAL closure method is feasible, effective, and safe for closing the gastric defect after EFTR in patients.

Endoscopic closure after intraluminal surgery.

Endoscopic submucosal dissection is established as a curative endoscopic method for gastrointestinal epithelial neoplasms with a high possibility of complete en bloc resection; however, postoperative adverse events of bleeding and delayed perforation remain. To prevent or minimize them, several techniques for endoscopic mucosal closure have been introduced, such as using endoscopic clips, combined use of hemoclips and supplement devices, and specially designed endoscopic suturing devices. Furthermore, endoscopic full-thickness suturing technique for gastrointestinal wall defect has been developed based on the concept in natural orifice transluminal endoscopic surgery and endoscopic full-thickness resection. Several closure techniques, including over-the-scope clip, threaded bars inserted in a hollow needle, stitches or staplers, and a curved needle and thread are reported. Secure closure of the iatrogenic defect may further expand the range of therapeutic endoscopy. Accumulation of evidence for the efficacy of endoscopic closure and establishment of these techniques are desired.

A comparison of two endoscopic closures: over-the-scope clip (OTSC) versus KING closure (endoloop + clips) in a randomized long-term experimental study.

BACKGROUND: Both over-the-scope clip (OTSC) and KING (endoloop + clips) closures provide reliable and safe full-thickness endoscopic closure. Nevertheless, OTSC clip demonstrated significantly inferior histological healing in the short-term follow-up. AIM: To compare OTSC versus KING closure of a perforation with regard to long-term effectiveness and macroscopic and histological quality of healing. METHODS: We performed a randomized experimental study with 16 mini-pigs (mean weight 43.2 ± 11.2 kg). A standardized perforation was performed on the anterior sigmoid wall. KING closure (n = 8) was attained by approximation of an endoloop fixed to the margins of a perforation with endoclips. OTSC closure (n = 8) was performed by deploying OTSC (OVESCO) over the defect. Pigs underwent a control sigmoidoscopy 8 months after the closure to assess the macroscopic quality of healing. Then, autopsy was performed and the rectosigmoid was sent for histopathological assessment. RESULTS: All closures were completed successfully without air leaks. The duration of closure was similar in both techniques (OTSC 17.8 ± 7.6 min vs. KING 19.6 ± 8.8 min). At autopsy, all KING closures (100 %) were healed with a flat scar without signs of leakage. Microscopically, no inflammatory changes were observed after KING closure. In the OTSC group, microscopic ulcers were present in two pigs (25 %), cryptal abscesses in three pigs (38 %) and significant neutrophil accumulation in all eight pigs (P < 0.01). Giant cell granulomas, dysplasia or abundant scarification was not observed in either group. CONCLUSIONS: Both OTSC and KING closures offer a long-term reliable seal of a gastrointestinal perforation without stenosis or fistulas. KING closure provides long-term histologically superior healing.

Novel endoscopic multi-firing-clip applicator for endoscopic closure of large colonic perforations.

BACKGROUND: Existing endoclip closure devices have difficulty in closing large colonic perforation. We developed a novel endoscopic multi-firing-clip applicator (EMFCA) system to address these limitations, and report on its initial evaluation. MATERIAL AND METHODS: The functionality and efficacy of the prototype EMFCA equipped with re-openable clamp and preloaded with four clips were assessed using standardized 1.5 cm incisions created in ex-vivo porcine colonic segments. Endoscopic closure of the lacerations with two, three and four clips (n = five for each group) was followed by measurement of the leakage pressure of the three groups. Finite element analysis (FEA) was performed to validate the clip behavior and reliability during deployment. RESULTS: All 15 perforations were sealed without leakage until fully distended. The leakage pressures of colonic lacerations sealed with two, three, and four clips were 26.1 ± 2.8 mmHg, 37.3 ± 7.3 mmHg and 42.3 ± 7.4 mmHg, respectively. The mean operation time to deploy one clip was 25.4 ± 5.2 seconds. On FEA, the deformation of the shape of the clip matched that of the intended design, with each clip sustaining a maximum stress of 648.5 MPa without any material failure during deployment. CONCLUSIONS: These initial results confirm the efficacy of the EMFCA prototype system for endoscopic closure of colonic perforations.

Endoscopic clips for the closure of acute iatrogenic perforations: Where do we stand?

BACKGROUND AND AIM: Iatrogenic perforation of the gut during endoscopy remains an uncommon but critical complication with significant morbidity and probable mortality than usual surgical treatment. Some authors have adopted a non-surgical closure method in chosen cases and, since 1993, endoclips have been used to close perforation in the stomach. The endoscopic practice of endoclips has been commonly used in the gut for hemostasis. Currently, the use of endoscopic techniques is increasing for the closure of endoscopic submucosal dissection or endoscopic mucosal resection. Endoscopic perforations that improved with endoscopic closure in the literature prior to 2008 have been previously described. In the present article, we present a descriptive review of cases with iatrogenic perforation in the gut treated with endoclips between 2008 and 2014. METHODS: Comprehensive literature screening and a systematic review using PubMed and Medline was done for all reports published between January 2008 and December 2014 using the endoclip technique in the closure of iatrogenic perforations. RESULTS: A total of 47 studies published between 2008 and 2014 using endoclips for the closure of iatrogenic perforations of the gut (nine esophagus, 11 stomach, 15 duodenum, 12 colon and rectum) were found. All studies were explained briefly and summarized in a table. CONCLUSIONS: There is strong evidence to show the efficacy of endoclips in the management of iatrogenic perforations, especially when recognized early. Limitations of endoclipping such as inefficiency against large perforations may be overcome by improving novel techniques in the future.

Delayed bleeding after endoscopic submucosal dissection for non-ampullary superficial duodenal neoplasias might be prevented by prophylactic endoscopic closure: analysis of risk factors.

BACKGROUND AND AIM: Duodenal endoscopic submucosal dissection (ESD) is technically challenging because of anatomical specificities and, to date, has not been validated concerning the high rate of complications such as perforation and delayed bleeding. In the present study, the risk factors for delayed bleeding after duodenal ESD are presented with the goal of establishing preventive measures. METHODS: We analyzed 63 patients with non-ampullary superficial duodenal neoplasias treated by ESD from April 2005 to March 2014. To analyze the risk factors of delayed bleeding after duodenal ESD, we divided the patients into a delayed bleeding group and a non-bleeding group. To verify the risk factors of delayed bleeding after duodenal ESD, we analyzed various patient-, lesion-, and treatment-related factors. RESULTS: Delayed bleeding was experienced in 11 patients (17.5%) Univariate analysis of patient-related risk factors of delayed bleeding indicated no significant risk factor. Univariate analysis of lesion-related and treatment-related risk factors indicated only endoscopic closure as a significant risk factor. Multivariate analysis also identified endoscopic closure (not done > done: P = 0.049) as an independent factor significantly associated with delayed bleeding after duodenal ESD. Hypertension (present > absent: P = 0.055) showed a non-significant tendency of association by multivariate analysis. CONCLUSIONS: This retrospective evaluation found that endoscopic closure was associated with a reduced risk of delayed bleeding after duodenal ESD. Delayed bleeding after duodenal ESD might be prevented by prophylactic endoscopic closure.

Multipurpose use of the 'bear claw' (over-the-scope-clip system) to treat endoluminal gastrointestinal disorders.

BACKGROUND AND AIM: The 'bear-claw' or over-the-scope-clip system (OTSC; Ovesco Endoscopy, Tübingen, Germany) is a new clipping device developed for closure of large luminal gastrointestinal (GI) defects. The aim of the present study was to evaluate the clinical outcomes of patients treated with the OTSC. METHODS: The present study was an observational, open-label, retrospective, single-arm case series conducted at two hospitals with tertiary care endoscopy. It involved 20 clip applications in 16 patients (median age 65.8 years [range 51-90 years], seven women) with GI defects from fistulas and anastomotic dehiscence and peptic ulcer bleeding. RESULTS: The range of indications included gastrointestinal bleeding (n=6), gastrocutaneous fistulas (n=3), esophagotracheal and/or esophagopleural fistulae (n=3), resection ofsubmucosal tumor (n=2), stent fixation (n=1), and anastomotic leak after esophagectomy (n=1). The overall success rate for the OTSC device was 75% (12 out of 16 patients). The overall per case success rate was 70% (14 of 20 applications). Mean follow up was 10 months (range 1-10). There were no complications (0%) related to endoscopy, sedation or application of the clipping device. CONCLUSIONS: The OTSC system is a useful device in a variety of clinical scenarios including the management of larger GI leaks and fistulas, GI bleeding, full-thickness resection of tumors, and stent anchoring, even in very old and frail patients.

Endoscopic techniques for management of large colorectal polyps, strictures and leaks.

The implementation of screening colonoscopy with polyp removal has significantly decreased mortality rates associated with colorectal cancer (CRC), although it remains a major cause of cancer-related deaths globally. CRC typically originates from adenomatous polyps, and increased removal of these growths has led to reduced CRC incidence and mortality. Endoscopic polypectomy techniques, including hot and cold snare polypectomy, play a pivotal role in this process. While both methods are effective for small polyps (<10 mm), recent evidence favors cold snare polypectomy due to its superior safety profile and comparable complete resection rates. Large polyps (>10 mm), particularly those with advanced features, pose increased cancer risks and often require meticulous assessment and advanced endoscopic techniques, including endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD), for resection. This chapter also provides a practical overview of endoscopic techniques for managing colonic obstructions and pericolonic fluid collections, detailing their indications, advantages, disadvantages, and complications. The goal is to improve understanding and application in clinical practice. Additionally, we provide a summary of endoscopic closure techniques that have revolutionized the management of perforations and fistulas, offering safe and effective alternatives to surgery.

Endoscopic closure of experimental iatrogenic gastric fundus perforation using over-the-scope clips in a surviving canine model.

BACKGROUND AND AIM: To evaluate the effectiveness and outcomes of endoscopic closure of a gastric fundus perforation using over-the-scope clips (OTSCs) system in a surviving canine model. METHODS: Gastric fundus perforations (20-mm diameter) were created by an endoscopic needle-knife in six dogs. The perforations then were closed by the OTSC system. Gastroscopy was performed to evaluate the postoperative perforation healing every week. The animals were sacrificed 4 weeks later to examine the possible intraperitoneal complications, and the healing of the perforation was examined histopathologically. RESULTS: The gastric fundus perforations could primarily be closed using one OTSC in each experimental dog, and the mean time of the procedure was 17.3 ± 7.6 min (9-26 min). All animals survived without postoperative complications. The OTSC retention was observed in one dog at the end of 4 weeks, and the apparent foreign-body reaction was examined pathologically. CONCLUSIONS: Our surviving animal study demonstrated that the OTSC clip system could reliably close gastric fundus perforations without complications.