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.

Sustained virologic response to direct-acting antiviral therapy in patients with chronic hepatitis C and hepatocellular carcinoma: A systematic review and meta-analysis.

BACKGROUND & AIMS: The effect of hepatocellular carcinoma (HCC) on the response to interferon-free direct-acting antiviral (DAA) therapy in patients with chronic hepatitis C (CHC) infection remains unclear. Using a systematic review and meta-analysis approach, we aimed to investigate the effect of DAA therapy on sustained virologic response (SVR) among patients with CHC and either active, inactive or no HCC. METHODS: PubMed, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials were searched from 1/1/2013 to 9/24/2018. The pooled SVR rates were computed using DerSimonian-Laird random-effects models. RESULTS: We included 49 studies from 15 countries, comprised of 3,341 patients with HCC and 35,701 without HCC. Overall, the pooled SVR was lower in patients with HCC than in those without HCC (89.6%, 95% CI 86.8-92.1%, I2 = 79.1% vs. 93.3%, 95% CI 91.9-94.7%, I2 = 95.0%, p = 0.0012), translating to a 4.8% (95% CI 0.2-7.4%) SVR reduction by meta-regression analysis. The largest SVR reduction (18.8%) occurred in patients with active/residual HCC vs. inactive/ablated HCC (SVR 73.1% vs. 92.6%, p = 0.002). Meanwhile, patients with HCC who received a prior liver transplant had higher SVR rates than those who did not (p <0.001). Regarding specific DAA regimens, patients with HCC treated with ledipasvir/sofosbuvir had lower SVR rates than patients without HCC (92.6%, n = 884 vs. 97.8%, n = 13,141, p = 0.026), but heterogeneity was high (I2 = 84.7%, p <0.001). The SVR rate was similar in patients with/without HCC who were treated with ombitasvir/paritaprevir/ritonavir ±â€¯dasabuvir (n = 101) (97.2% vs. 94.8%, p = 0.79), or daclatasvir/asunaprevir (91.7% vs. 89.8%, p = 0.66). CONCLUSION: Overall, SVR rates were lower in patients with HCC, especially with active HCC, compared to those without HCC, though heterogeneity was high. Continued efforts are needed to aggressively screen, diagnose, and treat HCC to ensure higher CHC cure rates. LAY SUMMARY: There are now medications (direct-acting antivirals or "DAAs") that can "cure" hepatitis C virus, but patients with hepatitis C and liver cancer may be less likely to achieve cure than those without liver cancer. However, patients with liver cancer are also more likely to have advanced liver disease and risk factors that can decrease cure rates, so better controlled studies are needed to confirm these findings.

Artificial Intelligence-Assisted Colonoscopy in Real-World Clinical Practice: A Systematic Review and Meta-Analysis.

INTRODUCTION: Artificial intelligence (AI) could minimize the operator-dependent variation in colonoscopy quality. Computer-aided detection (CADe) has improved adenoma detection rate (ADR) and adenomas per colonoscopy (APC) in randomized controlled trials. There is a need to assess the impact of CADe in real-world settings. METHODS: We searched MEDLINE, EMBASE, and Web of Science for nonrandomized real-world studies of CADe in colonoscopy. Random-effects meta-analyses were performed to examine the effect of CADe on ADR and APC. The study is registered under PROSPERO (CRD42023424037). There was no funding for this study. RESULTS: Twelve of 1,314 studies met inclusion criteria. Overall, ADR was statistically significantly higher with vs without CADe (36.3% vs 35.8%, risk ratio [RR] 1.13, 95% confidence interval [CI] 1.01-1.28). This difference remained significant in subgroup analyses evaluating 6 prospective (37.3% vs 35.2%, RR 1.15, 95% CI 1.01-1.32) but not 6 retrospective (35.7% vs 36.2%, RR 1.12, 95% CI 0.92-1.36) studies. Among 6 studies with APC data, APC rate ratio with vs without CADe was 1.12 (95% CI 0.95-1.33). In 4 studies with GI Genius (Medtronic), there was no difference in ADR with vs without CADe (RR 0.96, 95% CI 0.85-1.07). DISCUSSION: ADR, but not APC, was slightly higher with vs without CADe among all available real-world studies. This difference was attributed to the results of prospective but not retrospective studies. The discrepancies between these findings and those of randomized controlled trials call for future research on the true impact of current AI technology on colonoscopy quality and the subtleties of human-AI interactions.

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

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

Use of a novel dual-action clip for closure of complex endoscopic resection defects.

Video 1Use of dual-action clips and clips with added atraumatic teeth to close complex endoscopic resection defects.