Low delayed bleeding and high complete closure rate of mucosal defects with the novel through-the-scope dual-action tissue clip after endoscopic resection of large nonpedunculated colorectal lesions (with video).

BACKGROUND AND AIMS: Complete closure after endoscopic resection of large nonpedunculated colorectal lesions (LNPCLs) can reduce delayed bleeding but is challenging with conventional through-the-scope (TTS) clips alone. The novel dual-action tissue (DAT) clip has clip arms that open and close independently of each other, facilitating tissue approximation. We aimed to evaluate the rate of complete closure and delayed bleeding with the DAT clip after endoscopic resection of LNPCLs. METHODS: This was a multicenter prospective cohort study of all patients who underwent defect closure with the DAT clip after EMR or endoscopic submucosal dissection (ESD) of LNPCLs ≥20 mm from July 2022 to May 2023. Delayed bleeding was defined as a bleeding event requiring hospitalization, blood transfusion, or any intervention within 30 days after the procedure. Complete closure was defined as apposition of mucosal defect margins without visible submucosal areas <3 mm along the closure line. RESULTS: One hundred seven patients (median age, 64 years; 42.5% women) underwent EMR (n = 63) or ESD (n = 44) of LNPCLs (median size, 40 mm; 74.8% right-sided colon) followed by defect closure. Complete closure was achieved in 96.3% (n = 103) with a mean of 1.4 ± .6 DAT clips and 2.9 ± 1.8 TTS clips. Delayed bleeding occurred in 1 patient (.9%) without requiring additional interventions. CONCLUSIONS: The use of the DAT clip in conjunction with TTS clips achieved high complete defect closure after endoscopic resection of large LNPCLs and was associated with a .9% delayed bleeding rate. Future comparative trials and formal cost-analyses are needed to validate these findings. (Clinical trial registration number: NCT05852457.).

Strategies to manage the difficult colonoscopy.

During endoscopy, an endoscopist is inevitably faced with the occasional "difficult colonoscopy," in which the endoscopist finds it challenging to advance the endoscope to the cecum. Beyond optimization of technique, with minimized looping, minimal insufflation, sufficient sedation, and abdominal splinting when needed, sometimes additional tools may be needed. In this review, we cover available techniques and technologies to help navigate the difficult colonoscopy, including the ultrathin colonoscope, rigidizing overtube, balloon-assisted colonoscopy and the abdominal compression device.

Multicenter evaluation of recurrence in endoscopic submucosal dissection and endoscopic mucosal resection in the colon: A Western perspective.

BACKGROUND: While colon endoscopic mucosal resection (EMR) is an effective technique, removal of larger polyps often requires piecemeal resection, which can increase recurrence rates. Endoscopic submucosal dissection (ESD) in the colon offers the ability for en bloc resection and is well-described in Asia, but there are limited studies comparing ESD vs EMR in the West. AIM: To evaluate different techniques in endoscopic resection of large polyps in the colon and to identify factors for recurrence. METHODS: The study is a retrospective comparison of ESD, EMR and knife-assisted endoscopic resection performed at Stanford University Medical Center and Veterans Affairs Palo Alto Health Care System between 2016 and 2020. Knife-assisted endoscopic resection was defined as use of electrosurgical knife to facilitate snare resection, such as for circumferential incision. Patients ≥ 18 years of age undergoing colonoscopy with removal of polyp(s) ≥ 20 mm were included. The primary outcome was recurrence on follow-up. RESULTS: A total of 376 patients and 428 polyps were included. Mean polyp size was greatest in the ESD group (35.8 mm), followed by knife-assisted endoscopic resection (33.3 mm) and EMR (30.5 mm) (P < 0.001). ESD achieved highest en bloc resection (90.4%) followed by knife-assisted endoscopic resection (31.1%) and EMR (20.2%) (P < 0.001). A total of 287 polyps had follow-up (67.1%). On follow-up analysis, recurrence rate was lowest in knife-assisted endoscopic resection (0.0%) and ESD (1.3%) and highest in EMR (12.9%) (P = 0.0017). En bloc polyp resection had significantly lower rate of recurrence (1.9%) compared to non-en bloc (12.0%, P = 0.003). On multivariate analysis, ESD (in comparison to EMR) adjusted for polyp size was found to significantly reduce risk of recurrence [adjusted hazard ratio 0.06 (95%CI: 0.01-0.57, P = 0.014)]. CONCLUSION: In our study, EMR had significantly higher recurrence compared to ESD and knife-assisted endoscopic resection. We found factors including resection by ESD, en bloc removal, and use of circumferential incision were associated with significantly decreased recurrence. While further studies are needed, we have demonstrated the efficacy of ESD in a Western population.

Use of anchor pronged clips to close complex polyp resection defects.

Video 1Demonstration of anchored pronged clips to close complex polyp resection defects.

Evaluation of Computer-Aided Detection During Colonoscopy in the Community (AI-SEE): A Multicenter Randomized Clinical Trial.

INTRODUCTION: There has been increasing interest in artificial intelligence in gastroenterology. To reduce miss rates during colonoscopy, there has been significant exploration in computer-aided detection (CADe) devices. In this study, we evaluate the use of CADe in colonoscopy in community-based, nonacademic practices. METHODS: Between September 28, 2020, and September 24, 2021, a randomized controlled trial (AI-SEE) was performed evaluating the impact of CADe on polyp detection in 4 community-based endoscopy centers in the United States Patients were block-randomized to undergoing colonoscopy with or without CADe (EndoVigilant). Primary outcomes measured were adenomas per colonoscopy and adenomas per extraction (the percentage of polyps removed that are adenomas). Secondary end points included serrated polyps per colonoscopy; nonadenomatous, nonserrated polyps per colonoscopy; adenoma and serrated polyp detection rates; and procedural time. RESULTS: A total of 769 patients were enrolled (387 with CADe), with similar patient demographics between the 2 groups. There was no significant difference in adenomas per colonoscopy in the CADe and non-CADe groups (0.73 vs 0.67, P = 0.496). Although the use of CADe did not improve identification of serrated polyps per colonoscopy (0.08 vs 0.08, P = 0.965), the use of CADe increased identification of nonadenomatous, nonserrated polyps per colonoscopy (0.90 vs 0.51, P < 0.0001), resulting in detection of fewer adenomas per extraction in the CADe group. The adenoma detection rate (35.9 vs 37.2%, P = 0.774) and serrated polyp detection rate (6.5 vs 6.3%, P = 1.000) were similar in the CADe and non-CADe groups. Mean withdrawal time was longer in the CADe group compared with the non-CADe group (11.7 vs 10.7 minutes, P = 0.003). However, when no polyps were identified, there was similar mean withdrawal time (9.1 vs 8.8 minutes, P = 0.288). There were no adverse events. DISCUSSION: The use of CADe did not result in a statistically significant difference in the number of adenomas detected. Additional studies are needed to better understand why some endoscopists derive substantial benefits from CADe and others do not. ClinicalTrials.gov number: NCT04555135.

A novel through-the-scope helix tack-and-suture device for mucosal defect closure following colorectal endoscopic submucosal dissection: a multicenter study.

BACKGROUND: Complete closure of large mucosal defects following colorectal endoscopic submucosal dissection (ESD) with through-the-scope (TTS) clips is oftentimes not possible. We aimed to report our early experience of using a novel TTS suturing system for the closure of large mucosal defects after colorectal ESD. METHODS: We performed a retrospective multicenter cohort study of consecutive patients who underwent attempted prophylactic defect closure using the TTS suturing system after colorectal ESD. The primary outcome was technical success in achieving complete defect closure, defined as a < 5 mm residual mucosal defect in the closure line using TTS suturing, with or without adjuvant TTS clips. RESULTS: 82 patients with a median defect size of 30 (interquartile range 25-40) mm were included. Technical success was achieved in 92.7 % (n = 76): TTS suturing only in 44 patients (53.7 %) and a combination of TTS suturing to approximate the widest segment followed by complete closure with TTS clips in 32 (39.0 %). Incomplete/partial closure, failure of appropriate TTS suture deployment, and the need for over-the-scope salvage closure methods were observed in 7.3 % (n = 6). One intraprocedural bleed, one delayed bleed, and three intraprocedural perforations were observed. There were no adverse events related to placement of the TTS suture. CONCLUSION: The TTS suture system is an effective and safe tool for the closure of large mucosal defects after colorectal ESD and is an alternative when complete closure with TTS clips alone is not possible.

Randomized controlled trial investigating use of submucosal injection of EverLift™ in rates of complete resection of non-pedunculated 4-9 mm polyps.

INTRODUCTION: Currently, cold snare polypectomy (CSP) without submucosal injection is recommended for removing polyps < 10 mm. Use of viscous submucosal agents has not been previously evaluated in CSP. We investigate the potential role of EverLift™ (GI Supply, Pennsylvania) in CSP. METHODS: The study is a single-center prospective randomized non-inferiority clinical trial evaluating CSP of non-pedunculated 4-9 mm polyps, with or without submucosal injection of EverLift™. Patients 18-80 years of age presenting for colonoscopy were recruited. Eligible polyps underwent block randomization to CSP with or without EverLift™. Following CSP, two biopsies were performed at the CSP site margin. The primary non-inferiority outcome was complete resection rate, defined by absence of residual polyp in the margin biopsies (non-inferiority margin -10%). RESULTS: A total of 291 eligible polyps underwent CSP, with 142 removed using EverLift™. There was similar polyp size and distribution of pathology between the two groups. Overall, there was a low rate of positive margins with (1.4%) or without submucosal injection (2.8%), with no significant difference in complete resection (difference 1.28%, 95% CI: -2.66 to 5.42%), demonstrating non-inferiority of EverLift™ injection. Use of EverLift™ significantly increased CSP time (109.8 vs 38.8 s, p < 0.0001) and frequency of use of hemostatic clips (13.4 vs 3.6%, p = 0.002). CONCLUSION: Submucosal injection of EverLift™ was non-inferior to CSP of 4-9 mm polyps without injection and increased time for resection as well as use of hemostatic clips to control acute bleeding. Our results suggest that polypectomy of 4-9 mm polyps can be safely performed without submucosal injection of EverLift™.

Endoscopic submucosal dissection for colorectal dysplasia in inflammatory bowel disease: a US multicenter study.

Background and study aims In patients with inflammatory bowel disease (IBD), endoscopically visible lesions with distinct borders can be considered for endoscopic resection. The role of endoscopic submucosal dissection (ESD) for these lesions is not well defined because of a paucity of data. We aimed to evaluate the outcomes of colorectal ESD of dysplastic lesions in patients with IBD across centers in the United States. Patients and methods This was a retrospective analysis of consecutive patients with IBD who were referred for ESD of dysplastic colorectal lesions at nine centers. The primary endpoints were the rates of en bloc resection and complete (R0) resection. The secondary endpoints were the rates of adverse events and lesion recurrence. Results A total of 45 dysplastic lesions (median size 30mm, interquartile range [IQR] 23 to 42 mm) in 41 patients were included. Submucosal fibrosis was observed in 73 %. En bloc resection was achieved in 43 of 45 lesions (96 %) and R0 resection in 34 of 45 lesions (76 %). Intraprocedural perforation occurred in one patient (2.4 %) and was treated successfully with clip placement. Delayed bleeding occurred in four patients (9.8 %). No severe intraprocedural bleeding or delayed perforation occurred. During a median follow-up of 18 months (IQR 13 to 37 months), local recurrence occurred in one case (2.6 %). Metachronous lesions were identified in 11 patients (31 %). Conclusions ESD, when performed by experts, is safe and effective for large, dysplastic colorectal lesions in patients with IBD. Despite the high prevalence of submucosal fibrosis, en bloc resection was achieved in nearly all patients with IBD undergoing ESD. Careful endoscopic surveillance is necessary to monitor for local recurrence and metachronous lesions after ESD.

Randomized Controlled Trial Investigating Cold Snare and Forceps Polypectomy Among Small POLYPs in Rates of Complete Resection: The TINYPOLYP Trial.

INTRODUCTION: Optimizing complete resection during colonoscopy is important because residual neoplastic tissue may play a role in interval cancers. The US Multi-Society Task Force recommends diminutive (≤5 mm) and small (6-9 mm) polyps be removed by cold snare polypectomy (CSP). However, evidence is less clear whether CSP retains significant advantage over cold forceps polypectomy (CFP) for polyps ≤3 mm. METHODS: This study is a single-center prospective noninferiority randomized clinical trial evaluating CFP and CSP for nonpedunculated polyps ≤3 mm. Patients 18 years and older undergoing colonoscopy for any indication were recruited. During each colonoscopy, polyps underwent block randomization to removal with CFP or CSP. After polypectomy, 2 biopsies were taken from the polypectomy margin. The primary noninferiority outcome was the complete resection rate, defined by absence of residual polyp in the margin biopsies. RESULTS: A total of 179 patients were included. Patients had similar distribution in age, sex, race/ethnicity, as well as indication of procedure. A total of 279 polyps ≤3 mm were identified, with 138 in the CSP group and 141 in the CFP group. Mean polypectomy time was longer for CSP compared with CFP (42.3 vs 23.2 seconds, P < 0.001), although a higher proportion of polyps removed by CFP were removed in more than 1 piece compared with CSP (15.6 vs 3.6%, P < 0.001). There were positive margin biopsies in 2 cases per cohort, with a complete resection rate of 98.3% in both groups. There was no significant difference in cohorts in complete resection rates (difference in complete resection rates was 0.057%, 95% confidence interval: -4.30% to 4.53%), demonstrating noninferiority of CFP compared with CSP. DISCUSSION: Use of CFP was noninferior to CSP in the complete resection of nonpedunculated polyps ≤3 mm. CSP required significantly more time to perform compared with CFP. CFP should be considered an acceptable alternative to CSP for removal of polyps ≤3 mm.

Clinical evaluation of a real-time artificial intelligence-based polyp detection system: a US multi-center pilot study.

Artificial intelligence (AI) has increasingly been employed in multiple fields, and there has been significant interest in its use within gastrointestinal endoscopy. Computer-aided detection (CAD) can potentially improve polyp detection rates and decrease miss rates in colonoscopy. However, few clinical studies have evaluated real-time CAD during colonoscopy. In this study, we analyze the efficacy of a novel real-time CAD system during colonoscopy. This was a single-arm prospective study of patients undergoing colonoscopy with a real-time CAD system. This AI-based system had previously been trained using manually labeled colonoscopy videos to help detect neoplastic polyps (adenomas and serrated polyps). In this pilot study, 300 patients at two centers underwent elective colonoscopy with the CAD system. These results were compared to 300 historical controls consisting of consecutive colonoscopies performed by the participating endoscopists within 12 months prior to onset of the study without the aid of CAD. The primary outcome was the mean number of adenomas per colonoscopy. Use of real-time CAD trended towards increased adenoma detection (1.35 vs 1.07, p = 0.099) per colonoscopy though this did not achieve statistical significance. Compared to historical controls, use of CAD demonstrated a trend towards increased identification of serrated polyps (0.15 vs 0.07) and all neoplastic (adenomatous and serrated) polyps (1.50 vs 1.14) per procedure. There were significantly more non-neoplastic polyps detected with CAD (1.08 vs 0.57, p < 0.0001). There was no difference in ≥ 10 mm polyps identified between the two groups. A real-time CAD system can increase detection of adenomas and serrated polyps during colonoscopy in comparison to historical controls without CAD, though this was not statistically significant. As this pilot study is underpowered, given the findings we recommend pursuing a larger randomized controlled trial to further evaluate the benefits of CAD.

Endoscopic full-thickness resection of polyps involving the appendiceal orifice: a multicenter international experience.

BACKGROUND: Endoscopic resection of lesions involving the appendiceal orifice remains a challenge. We aimed to report outcomes with the full-thickness resection device (FTRD) for the resection of appendiceal lesions and identify factors associated with the occurrence of appendicitis. METHODS: This was a retrospective study at 18 tertiary-care centers (USA 12, Canada 1, Europe 5) between November 2016 and August 2020. Consecutive patients who underwent resection of an appendiceal orifice lesion using the FTRD were included. The primary outcome was the rate of R0 resection in neoplastic lesions, defined as negative lateral and deep margins on post-resection histologic evaluation. Secondary outcomes included the rates of: technical success (en bloc resection), clinical success (technical success without need for further surgical intervention), post-resection appendicitis, and polyp recurrence. RESULTS: 66 patients (32 women; mean age 64) underwent resection of colonic lesions involving the appendiceal orifice (mean [standard deviation] size, 14.5 (6.2) mm), with 40 (61 %) being deep, extending into the appendiceal lumen. Technical success was achieved in 59/66 patients (89 %), of which, 56 were found to be neoplastic lesions on post-resection pathology. Clinical success was achieved in 53/66 (80 %). R0 resection was achieved in 52/56 (93 %). Of the 58 patients in whom EFTR was completed who had no prior history of appendectomy, appendicitis was reported in 10 (17 %), with six (60 %) requiring surgical appendectomy. Follow-up colonoscopy was completed in 41 patients, with evidence of recurrence in five (12 %). CONCLUSIONS: The FTRD is a promising non-surgical alternative for resecting appendiceal lesions, but appendicitis occurs in 1/6 cases.

Early Esophageal Cancer: What the Gastroenterologist Needs to Know.

Endoscopic findings in early esophageal cancer are often subtle and require careful inspection and meticulous endoscopic examination. When dysplasia is suspected, we recommend performing 1 or 2 targeted biopsies of the abnormal area and review with a pathologist specialized in evaluating gastrointestinal diseases. In the case of adenocarcinoma, after resection of any visible cancer, residual Barrett's can be treated by ablation. Endoscopic resection can offer the opportunity for patients to avoid surgery. Further studies are needed to evaluate the optimal management of circumferential and near-circumferential lesions as well as tools and techniques to facilitate the performance of endoscopic submucosal dissection and endoscopic mucosal resection.

Predictive factors for adenoma detection rates: a video study of endoscopist practices.

Background and study aims In 2015, the American Society for Gastrointestinal Endoscopy (ASGE) and American College of Gastroenterology (ACG) Task Force on Quality in Endoscopy deemed adenoma detection rate (ADR) the most important quality measure for colonoscopy. There has been much interest in factors that can increase ADR. To date, however, few studies have looked at what intra-procedural endoscopist practices are associated with improving ADR. We conducted a retrospective review of colonoscopy videos to evaluate intra-procedural practices that could be associated with ADR. Methods Videos were recorded of colonoscopies performed between September and December 2017 at the Palo Alto Veterans Affairs Health Care System. Colonoscopies for screening and surveillance were included for video review. Factors assessed included withdrawal time, intra-procedural cleaning, inspection technique, and other variables (colon distention, removal of equivocal/hyperplastic polyps). A series of multiple regression analyses was conducted on variables of interest before running a final model of significant predictors. Results A total of 130 videos were reviewed from nine endoscopists whose ADRs ranged between 37.5 % and 73.7 %. The final regression model was significant (F = 15.35, df = 2, P  = 0.0044), R 2  = 0.8365) with close inspection of behind folds and quality of cecal inspection being the factors highly correlated with predicting ADR. Withdrawal and inspection times, colonic wall distention, removal of equivocal/hyperplastic polyps, quality of rectal inspection, suctioning, and washing were factors moderately correlated with predicting ADR. Conclusions We found that behind-fold inspection and a meticulous cecal inspection technique were predictive of a high ADR.

Is Submucosal Injection Helpful in Cold Snare Polypectomy for Small Colorectal Polyps?

BACKGROUND/AIMS: Cold snare polypectomy (CSP) is an effective method of polyp removal for small colorectal polyps. However, the effect of submucosal injection in cold snare endoscopic mucosal resection (CS-EMR) for small polyps is unclear. Therefore, this study aimed to evaluate the effect of submucosal injection in CS-EMR for small polyps. METHODS: Between 2018 and 2019, 100 consecutive small colorectal polyps (5-10 mm) were identified in 58 patients. The first 50 consecutive polyps were removed by CS-EMR, and the remaining 50 were removed by CSP. Demographic data, clinical data, endoscopic findings, procedure times, complication rates, and pathology data were collected. RESULTS: No difference in the complete resection rate was observed between the CS-EMR and CSP groups. A total of 9 polyps showed post-polypectomy bleeding (7 had immediate bleeding, 1 had delayed bleeding, and 1 had both immediate and delayed bleeding). No difference in the bleeding rate was observed between the two groups. In multivariate analysis, warfarin (odds ratio [OR], 42.334; 95% confidence interval [CI], 1.006-1,781.758) and direct-acting oral anticoagulants (OR, 35.244; 95% CI, 3.853-322.397) showed a significantly increased risk of bleeding. CONCLUSION: The effect of submucosal injection in CSP was not significant for small colorectal polyps.

Long-term outcomes of per-oral endoscopic myotomy compared to laparoscopic Heller myotomy for achalasia: a single-center experience.

INTRODUCTION: Many centers have reported excellent short-term efficacy of per-oral endoscopic myotomy (POEM) for the treatment of achalasia. However, long-term data are limited and there are few studies comparing the efficacy of POEM versus Heller Myotomy (HM). AIMS: To compare the long-term clinical efficacy of POEM versus HM. METHODS: Using a retrospective, parallel cohort design, all cases of POEM or HM for achalasia between 2010 and 2015 were assessed. Clinical failure was defined as (a) Eckardt Score > 3 for at least 4 weeks, (b) achalasia-related hospitalization, or (c) repeat intervention. All index manometries were classified via Chicago Classification v3. Pre-procedural clinical, manometric, radiographic data, and procedural data were reviewed. RESULTS: 98 patients were identified (55 POEM, 43 Heller) with mean follow-up of 3.94 years, and 5.44 years, respectively. 83.7% of HM patients underwent associated anti-reflux wrap (Toupet or Dor). Baseline clinical, demographic, radiographic, and manometric data were similar between the groups. There was no statistical difference in overall long-term success (POEM 72.7%, HM 65.1% p = 0.417, although higher rates of success were seen in Type III Achalasia in POEM vs Heller (53.3% vs 44.4%, p < 0.05). Type III Achalasia was the only variable associated with failure on a univariate COX analysis and no covariants were identified on a multivariate Cox regression. There was no statistical difference in GERD symptoms, esophagitis, or major procedural complications. CONCLUSION: POEM and HM have similar long-term (4-year) efficacy with similar adverse event and reflux rates. POEM was associated with greater efficacy in Type III Achalasia.

Water-assisted colonoscopy: an international modified Delphi review on definitions and practice recommendations.

BACKGROUND AND AIMS: Since 2008, a plethora of research studies has compared the efficacy of water-assisted (aided) colonoscopy (WAC) and underwater resection (UWR) of colorectal lesions with standard colonoscopy. We reviewed and graded the research evidence with potential clinical application. We conducted a modified Delphi consensus among experienced colonoscopists on definitions and practice of water immersion (WI), water exchange (WE), and UWR. METHODS: Major databases were searched to obtain research reports that could potentially shape clinical practice related to WAC and UWR. Pertinent references were graded (Grading of Recommendations, Assessment, Development and Evaluation). Extracted data supporting evidence-based statements were tabulated and provided to respondents. We received responses from 55 (85% surveyed) experienced colonoscopists (37 experts and 18 nonexperts in WAC) from 16 countries in 3 rounds. Voting was conducted anonymously in the second and third round, with ≥80% agreement defined as consensus. We aimed to obtain consensus in all statements. RESULTS: In the first and the second modified Delphi rounds, 20 proposed statements were decreased to 14 and then 11 statements. After the third round, the combined responses from all respondents depicted the consensus in 11 statements (S): definitions of WI (S1) and WE (S2), procedural features (S3-S5), impact on bowel cleanliness (S6), adenoma detection (S7), pain score (S8), and UWR (S9-S11). CONCLUSIONS: The most important consensus statements are that WI and WE are not the same in implementation and outcomes. Because studies that could potentially shape clinical practice of WAC and UWR were chosen for review, this modified Delphi consensus supports recommendations for the use of WAC in clinical practice.

Novel rigidizing overtube for colonoscope stabilization and loop prevention (with video).

BACKGROUND AND AIMS: Loop formation can impede endoscope advancement, destabilize the tip, and cause pain. Strategies to mitigate looping include torque-based reduction maneuvers, variable stiffness shafts, and abdominal splinting. In some cases, these strategies are insufficient, and there is need for novel instruments. Loop formation is of particular concern in colonoscopy, but it can also impact performance of other endoscopic procedures such as enteroscopy and altered-anatomy ERCP. In this case series we demonstrate the utility of a novel rigidizing overtube (Pathfinder; Neptune Medical, Burlingame, Calif, USA) in colonoscopy and other endoscopic procedures where loop management is critical. METHODS: We describe our initial experience with the Pathfinder overtube in 29 patients. The overtube is 85 cm long and can accommodate a pediatric colonoscope. In its native state, the overtube is extremely flexible. Once the overtube is advanced to the desired location, application of a vacuum to the device causes the device to become 15 times stiffer. The endoscope can then be advanced through the overtube without loop formation in the region that the overtube traverses. RESULTS: The overtube was used in 29 patients to assist with difficult procedures. Patients were predominantly men (n = 18; 62.1%), with a median age of 66 years (interquartile range, 57-72). One patient received an upper endoscopy (3.4%), 24 received colonoscopy (82.8%), and 4 received enteroscopy (13.8%). The overtube was used in 12 procedures for incomplete colonoscopy (41.4%), 6 for depth (20.7%), and 11 for stability (37.9%). Colonoscopy was performed in the setting of screening (n = 3), surveillance given polyp history (n = 7), referrals for polyp removal (n = 10), workup of iron deficiency anemia (n = 2), and incomplete colonoscopy (n = 1). The lower endoscopy cases had a median cecal intubation time of 5 minutes (interquartile range, 4.25-7). Enteroscopy was performed in 4 patients: In one patient the distal 60 cm of the ileum was examined with a pediatric colonoscope to exclude ileitis, in another the overtube was used to stabilize a 6-mm endoscope to traverse a tight Crohn's ileocolonic stricture, in a third patient altered-anatomy ERCP was performed using an enteroscope through the overtube to reach a hepaticojejunostomy, and in the final patient upper enteroscopy was performed and the mid-jejunum was reached. We present 4 cases that demonstrate the use of the overtube. There were no adverse events. CONCLUSIONS: Initial experience with a novel rigidizing overtube suggests that this tool can be useful in colonoscopy and other endoscopic procedures affected by looping.