Usefulness of an ultrathin endoscope in esophageal endoscopic submucosal dissection.

Background and study aims Endoscopic submucosal dissection (ESD) is sometimes challenging because of stenosis and scarring. We examined the use of an ultrathin endoscope for esophageal ESD, which is difficult using conventional endoscopes. Patients and methods A designated transparent hood and ESD knife for ultrathin endoscopes have been developed and clinically introduced. Esophageal ESD was performed on 303 lesions in 220 patients in our hospital from February 2021 to February 2023. Of them, an ultrathin endoscope was used on 26 lesions in 23 cases. The safety and utility of an ultrathin endoscope in esophageal ESD were retrospectively verified. Results All 26 lesions were resected en bloc, and serious complications such as perforation, massive bleeding, or pneumonia, were not observed. Lesions were found on the anal side of the stenosis and over the scarring in 38.6% (10/26) and 50% (13/26) of participants, respectively. Moreover, 46.2% of participants (12/26) had lesions on the cervical esophagus. The total procedure time was 64.1 ± 37.7 minutes, but the average time from oral incision to pocket creation was 121.2 ± 109.9 seconds. Conclusions Ultrathin endoscopes may be useful for difficult esophageal ESD.

Efficacy and safety of radial incision and cutting for nonsurgical refractory benign esophageal stricture.

Background and study aims Radial incision and cutting (RIC) was established to improve refractory esophageal anastomotic strictures but its efficacy and safety for nonsurgical refractory strictures remain unclear. To evaluate the usefulness of RIC in nonsurgical refractory strictures, we retrospectively compared outcomes between nonsurgical and surgical strictures. Patients and methods We retrospectively studied 54 consecutive patients who were initially treated with RIC for refractory benign esophageal stricture. The study variables included dysphasia score improvement rate, frequency of repeated RIC, cumulative patency rate, cumulative stricture improved rate, and adverse events(AEs), which were compared between nonsurgical (n = 21) and surgical (n = 33) stricture groups. Results Immediately after RIC, 90.5% of patients in the nonsurgical group and 84.8% of patients in the surgical group had improvement in dysphagia ( P = 0.69). The frequency of intervening repeated RIC was 42.9% in the nonsurgical group and 42.4% in the surgical group ( P = 0.98). During median follow-up of 22.3 months (range, 1.0-175.0), the cumulative patency rate ( P = 0.23) and cumulative stricture improvement rate ( P = 0.14) but there was not statistical difference between the two groups. Despite a low cumulative stricture improvement rate (9.5%) at 6 months after the first RIC in the nonsurgical group, 57.7% of patients no longer required endoscopic balloon dilatation at 2 years. The cumulative stricture improvement rate was significantly lower in patients with a history of radiation therapy. No severe AEs were observed in the nonsurgical group. Conclusions RIC for nonsurgical refractory benign esophageal stricture is an effective and safe treatment option.

Lymphovascular invasion is a dominant risk factor for lymph node metastasis in T2 rectal cancer.

Background and study aims Surgical resection is standard treatment of T2 rectal cancer due to risk of concomitant lymph node metastases (LNM). Local resection could potentially be an alternative to surgical treatment in a subgroup of patients with low risk of LNM. The aim of this study was to identify clinical and histopathological risk factors of LNM in T2 rectal cancer. Patients and methods This was a retrospective registry-based population study on prospectively collected data on all patients with T2 rectal cancer undergoing surgical resection in Sweden between 2009 and 2021. Potential risk factors of LNM, including age, gender, resection margin, lymphovascular invasion (LVI), histologic grade, mucinous cancer, and perineural invasion (PNI) were analyzed using univariate and multivariate logistic regression. Results Of 1607 patients, 343 (21%) with T2 rectal cancer had LNM. LVI (odds ratio [OR] = 4.21, P < 0.001) and age < 60 years (OR = 1.80, P < 0.001) were significant and independent risk factors. However, PNI (OR = 1.50, P = 0.15), mucinous cancer (OR = 1.14, P = 0.60), histologic grade (OR = 1.47, P = 0.07) and non-radical resection margin (OR = 1.64, P = 0.38) were not significant risk factors for LNM in multivariate analyses. The incidence of LNM was 15% in the absence of any risk factor. Conclusions This was a large study on LNM in T2 rectal cancer which showed that LVI is the dominant risk factor. Moreover, low age constituted an independent risk factor, whereas gender, resection margin, PNI, histologic grade, and mucinous cancer were not independent risk factors of LNM. Thus, these findings may provide a useful basis for management of patients after local resection of early rectal cancer.

Endoscopic ultrasound classification for prediction of endoscopic submucosal dissection resectability: PREDICT classification.

Background and study aims The safety of endoscopic submucosal dissection (ESD) has been reported, and the risk of lymph node metastasis is low for colorectal cancer if depth of invasion is the only non-curative factor on histological evaluation. ESD is increasingly performed even if submucosal (SM) invasion is suspected. However, reports about endoscopic findings for the criteria to predict ESD resectability remain limited. Endoscopic ultrasound (EUS) can directly visualize the tomographic image of the gastrointestinal wall and may help predict ESD resectability. Therefore, we investigated the possibility of predicting ESD resectability using EUS. Patients and methods We compared the association between EUS findings and pathological results for gastric or colorectal lesions with suspected SM invasion using white light endoscopy between June 2020 and January 2023. EUS findings were grouped based on the status of the underlying the tumor, as follows: Type I, submucosal layer was observed with reproducibility; Type II, submucosal layer not fully visible; and Type III, submucosal layer disrupted and muscularis propria (MP) layer thickened. Results Forty-one gastric cancer and 22 colorectal cancer cases were analyzed. The proportions of pathological VM0 (no tumor exposed on any vertical margin) for ESD-resected specimens were 89% and 33% for Type I and II, respectively, ( P ≤ 0.01). The proportions of cancer involving MP or deeper were significantly higher for Type II/III than for Type I (41% vs 0%, P ≤ 0.01). Conclusions EUS may have an important role in predicting ESD resectability of gastric and colorectal cancers suspected of having SM invasion.

Transcecal endoscopic appendectomy for management of complex appendiceal polyps extending into the appendiceal orifice.

Background and study aims Endoscopic resection of appendiceal orifice (AO) polyps extending inside the appendiceal lumen is challenging given the inability to determine polyp lateral margins and risk of appendicitis. Transcecal endoscopic appendectomy (TEA) ensures en bloc resection of these complex polyps. Patients and methods This case series includes patients who underwent TEA by a single endoscopist in the United States. Technical success was defined as achieving complete removal of the appendix along with AO polyp in an en bloc fashion. Results In total, nine patients were included (mean age 69.7 ± 9.6 years). The average appendix size was 4.07 ± 2.02 cm. Technical success was achieved in 100% of the patients. The average procedure length was 118.1 ± 44.21 minutes. The en bloc resection rate, R0 resection rate, and curative resection rates were 100%. Patients were observed for an average of 3.1 ± 1.6 days. One patient developed loculated fluid collection 9 days post procedure, which resolved on its own with oral antibiotic therapy. No other adverse events were recorded. Conclusions This was an early study of the feasibility of TEA in the United States. This novel technique, in early-stage development, is potentially safe and associated with a minimal risk profile in expert hands. Further prospective studies are needed to standardize the technique.

Loop9 closure technique for mucosal defects after colorectal endoscopic submucosal dissection (with video).

Background and study aims Mucosal defect closure after colorectal endoscopic submucosal dissection (ESD) has the potential to reduce the occurrence of delayed adverse events (AEs) such as bleeding and perforation. This study aimed to assess the feasibility and effectiveness of the Loop9 method for closing mucosal defects following colorectal ESD. Patients and methods A retrospective single-center study was conducted using prospectively collected data from May 2020 to March 2023. Loop9 was deployed through a single instrument channel and anchored with clips at the defect site. Closure was accomplished by tightening the loop and deploying additional conventional clips as needed for complete closure. The primary outcome was complete closure rate, with secondary outcomes including the sustained closure rate at 4 to 5 days post-ESD, closed defect size, closure time, number of additional clips, and incidence of delayed AEs. Results This study included 118 cases. Complete closure was achieved in 96.6% of cases (114/118) with a sustained closure rate of 93.9% (107/114). The median size of the closed mucosal defects was 30 mm (interquartile range [IQR]: 25-38, range: 15-74). The median closure time was 14 minutes (IQR: 11.25-17), and the median number of additional clips deployed was six (IQR: 4-7). Stenosis requiring balloon dilatation was observed in one patient; however, there were no instances of post-ESD bleeding or delayed perforation. Conclusions The Loop9 method proved feasible and effective for closing mucosal defects following colorectal ESD, achieving high rates of complete and sustained closure.

Outcome after colorectal full-thickness resection and management of recurrence.

Background and study aims Endoscopic full-thickness resection (eFTR) allows treatment of "difficult to resect" lesions not amenable to conventional endoscopic methods. Efficacy and safety of the system have already been proven in numerous studies. Follow-up data on outcome of colorectal eFTR and management of recurrences are still rare. Patients and methods All patients undergoing colorectal eFTR at our institution with at least one endoscopic follow-up examination were retrospectively analyzed. The primary endpoint was the rate of recurrent or residual lesions (RRLs) and the secondary endpoint was the rate of late adverse events (AEs). We further aimed to identify risk factors for RRLs and to describe their management. Results Between November 2014 and 2021, 141 patients underwent eFTR at University Medical Center Freiburg. Ninety-one patients fulfilled the inclusion criteria. Indications for eFTR were non-lifting adenoma (n = 65), subepithelial tumors (n = 18) and early carcinoma (n = 8). The median follow-up period was 17 months (range, 2-86). The overall RRL rate was 9.9% (9/91). A significant proportion of RRLs (6/9, 66%) were detected late. All RRLs occurred in the group of non-lifting adenoma, corresponding to a RRL rate of 13.8% in this subgroup. Thirty-three percent (3/9) were initially treated by hybrid eFTR. Of the RRLs, 66.6% could were successfully treated endoscopically. On χ2 analysis, the hybrid eFTR technique ( P = 0.006) was associated with a higher rate of RRL. No late AEs occurred. Conclusions The rate of RRL after colorectal eFTR is low and the majority could be treated endoscopically. For non-lifting adenomas and early carcinomas, close follow-up is mandatory to detect late recurrence. Long-term outcomes after hybrid eFTR need further investigation.

Learning curve for endoscopic submucosal dissection (ESD) in the United States: Large, untutored, single-operator experience.

Background and study aims Endoscopic submucosal dissection (ESD) allows removal of tumors en-bloc. Western adoption of ESD has been hindered by its steep learning curve. Western data regarding ESD learning curve are limited. We analyzed the learning curve of a single endoscopist at a tertiary referral center in the United States. Patients and methods All consecutive ESDs performed by a single endoscopist at a tertiary referral center in the United States from 2015 through 2022 were identified. Descriptive statistics and CUSUM analysis were used to describe the learning curve for en-bloc, R0 resection, and resection speed. Results In our study, 503 patients with 515 lesions were included. Severe submucosal fibrosis was found in 17% of the lesions. The rates of en-bloc, R0, and curative resections were 81.9%, 71.1%, and 68.4%, respectively. CUSUM analysis showed that the learning curve plateaued at 268, 347, and 170 cases for en-bloc resection, R0 resection, and achieving a resection speed > 9 cm 2 /hr. Fibrosis significantly affected the R0 resection rate in the regression analysis (95% confidence interval 0.21-0.55). In colonic ESD curve analysis, the learning plateau was reached after 185 cases for both en-bloc and R0 resection. Conclusions Following ex-vivo training in an animal model, an untutored expert operator achieved competency in ESD between 250 and 350 procedures. Our data can inform development of future training programs in the West.

Endoscopic resection in subepithelial lesions of the upper gastrointestinal tract: Experience at a tertiary referral hospital in The Netherlands.

Background and study aims Histological confirmation of subepithelial lesions (SELs) in the upper gastrointestinal tract remains challenging. Endoscopic resection of SELs is increasingly used for its excellent diagnostic yield and opportunity to do away with continued surveillance. In this study, we aimed to evaluate the indications, success rates and complications of different endoscopic resection techniques for SELs at a large, tertiary referral hospital in Rotterdam, The Netherlands. Patients and methods Data between October 2013 and December 2021 were retrospectively collected and analyzed. Main outcomes were R0-resection rate, en bloc resection rate, recurrence rate, and procedure-related adverse events (AEs) (Clavien-Dindo). Secondary outcomes were procedure time, need for surgical intervention, and clinical impact on patient management. Results A total of 58 patients were referred for endoscopic resection of upper gastrointestinal SELs. The median diameter of lesions was 20 mm (range 7-100 mm). Median follow-up time was 5 months (range 0.4-75.7). Forty-eight procedures (83%) were completed successfully leading to en bloc resection in 85% and R0-resection in 63%. Procedure-related AEs occurred in six patients (13%). Severe complications (CD grade 3a) were seen in three patients. The local recurrence rate for (pre)malignant diagnosis was 2%. Additional surgical intervention was needed in seven patients (15%). A total of 32 patients (67%) could be discharged from further surveillance after endoscopic resection. Conclusions Endoscopic resection is a safe and effective treatment for SELs and offers valuable information about undetermined SELs for which repeated sampling attempts have failed to provide adequate tissue for diagnosis.

The white ring sign is useful for differentiating between fundic gland polyps and gastric adenocarcinoma of the fundic gland type.

Background and study aims Gastric adenocarcinoma of the fundic gland type (GA-FG) is characterized by an elevated lesion with vessel dilation exhibiting branching architecture (DVBA). However, this feature is also found in fundic gland polyps (FGPs), posing a challenge in their differentiation. In this study, we aimed to investigate the clinicopathological features of gastric elevated lesions with DVBA and assess the efficacy of the white ring sign (WRS) as a novel marker for distinguishing between FGPs and GA-FGs. Methods We analyzed 159 gastric elevated lesions without DVBA and 51 gastric elevated lesions with DVBA, further dividing the latter into 39 in the WRS-positive group and 12 in the WRS-negative group. The clinicopathological features, diagnostic accuracy, and inter-rater reliability were analyzed. Results Univariate and multivariate analyses for gastric elevated lesions with DVBA identified the histological type consistent with FGPs and GA-FGs, along with the presence of round pits in the background gastric mucosa, as independent predictors. FGPs were present in 92.3% (36/39) of the WRS-positive group and GA-FGs were observed in 50.0% (6/12) of the WRS-negative group. WRS positivity and negativity exhibited high diagnostic accuracy, with 100% sensitivity, 80.0% specificity, and 94.1% accuracy for FGPs, and 100% sensitivity, 86.7% specificity, and 88.2% accuracy for GA-FGs. Kappa values for WRS between experts and nonexperts were 0.891 and 0.841, respectively, indicating excellent agreement. Conclusions WRS positivity and negativity demonstrate high diagnostic accuracy and inter-rater reliability for FGPs and GA-FGs, respectively, suggesting that WRS is a useful novel marker for distinguishing between FGPs and GA-FGs.

Outcomes in colorectal endoscopic submucosal dissection for large protruded lesions: A retrospective multicenter study.

Background and study aims Colorectal endoscopic submucosal dissection (ESD) is increasingly used for treating early-stage colorectal cancer, including large, protruded lesions (LPL). However, the challenges posed by LPLs, especially those accompanied by severe fibrosis or muscle-retracting sign (MRS), remain unclear. This study aims to investigate ESD outcomes for LPL, focusing on factors such as tumor size and, submucosal fibrosis. Patients and methods In a multicenter retrospective study (June 2012 to May 2023), data from 526 patients with 542 LPL lesions (≥ 2 cm) were analyzed. Parameters included lesion size, procedure time, dissection speed, physician experience, submucosal fibrosis, and adverse events. The tunnel method, including the double tunnel method, was used for cases with severe fibrosis or MRS. Multivariate analysis assessed factors affecting procedure difficulty, particularly LPLs ≥ 4 cm. Results The study revealed an impressive en bloc resection rate of 97.8% and a curative resection rate of 78.6% for LPLs. Notably, fibrosis and MRS were present in 25% and 18% of 4-cm LPLs, respectively, and their frequency tended to increase as the tumor diameter increased. One treatment strategy for LPLs was the tunneling method, which was used most frequently (41 cases, 7.6%). Factors affecting dissection speed included larger tumor size, submucosal fibrosis, MRS, and physician experience. Conclusions Treating LPLs through colorectal ESD presents significant challenges, especially in patients with fibrosis and MRS. This study highlights the importance of recognizing these complexities, and that more reliable resection strategy must be established for accurate pathological evaluation.

Safety of cold resection of non-ampullary duodenal polyps: Systematic review and meta-analysis.

Background and study aims Endoscopic resection has traditionally involved electrosurgical cautery (hot snare) to resect premalignant polyps. Recent data have suggested superior safety of cold resection. We aimed to assess the safety of cold compared with traditional (hot) resection for non-ampullary duodenal polyps. Methods We performed a systematic review ending in September 2022. The primary outcome of interest was the adverse event (AE) rate for cold compared with hot polyp resection. We reported odds ratios with 95% confidence intervals (CIs). Secondary outcomes included rates of polyp recurrence and post-polypectomy syndrome. We assessed publication bias with the classic fail-safe test and used forest plots to report pooled effect estimates. We assessed heterogeneity using I 2 index. Results Our systematic review identified 1,215 unique citations. Eight of these met inclusion criteria, seven of which were published manuscripts and one of which was a recent meeting abstract. On random effect modeling, cold resection was associated with significantly lower odds of delayed bleeding compared with hot resection. The difference in the odds of perforation (odds ratio [OR] 0.31 [95% confidence interval [CI] 0.05-2.87], P =0.2, I 2 =0) and polyp recurrence (OR 0.75 [95% CI 0.15-3.73], P =0.72, I 2 =0) between hot and cold resection was not statistically significant. There were no cases of post-polypectomy syndrome reported with either hot or cold techniques. Conclusions Cold resection is associated with lower odds of delayed bleeding compared with hot resection for duodenal tumors. There was a trend toward higher odds of perforation and recurrence following hot resection, but this trend was not statistically significant.

A new through-the-scope clip with anchor prongs is safe and successful for a variety of endoscopic uses.

Background and study aims Endoscopic through-the-scope clips (TTSC) are used for hemostasis and closure. We documented the performance of a new TTSC with anchor prongs. Patients and methods We conducted a prospective case series of the new TTSC in 50 patients with an indication for endoscopic clipping at three hospitals in the United States and Canada. Patients were followed for 30 days after the index procedure. Outcomes included defect closure and rate of serious adverse events (SAEs) related to the device or procedure. Results Fifty patients had 56 clipping procedures. Thirty-four procedures were clipping after endoscopic mucosal resection (EMR) in the colon (33) or stomach (1), 16 after polypectomy, two for hemostasis of active bleeding, and one each for fistula closure, per-oral endoscopic myotomy mucosal closure, or anchoring a feeding tube. Complete defect closure was achieved in 32 of 33 colon EMR defects and 21 of 22 other defects. All clips were placed per labeled directions for use. In 41 patients (82.0%), prophylaxis of delayed bleeding was reported as an indication for endoscopic clipping. There were three instances of delayed bleeding. There were no device-related SAEs. The only technical difficulty was one instance of premature clip deployment. Conclusions A novel TTSC with anchor prongs showed success in a range of defect closures, an acceptable safety profile, and low incidence of technical difficulties.

Efficacy and safety of the water pressure method for endoscopic submucosal dissection in superficial pharyngeal cancer.

Background and study aims Superficial pharyngeal cancers can be cured with transoral surgery (TOS), which preserves organ function and quality of life. Pharyngeal endoscopic submucosal dissection (ESD) is challenging to perform because of limited maneuverability and complex anatomical features. The water pressure method (WPM) is useful for natural traction techniques during ESD and is potentially useful for pharyngeal ESD. This study aimed to investigate the short-term outcomes of WPM-ESD for pharyngeal lesions. Patients and methods Therapeutic outcomes of patients who underwent WPM-ESD for pharyngeal lesions at Keio University between May 2019 and February 2022 were retrospectively analyzed. Results Twenty-one pharyngeal lesions treated with WPM-ESD were analyzed. Three lesions were located in the oropharynx and 18 in the hypopharynx. All ESD procedures were performed under general anesthesia. The endoscopic en bloc resection rate was 100%. The median procedure time was 15 minutes (range 4-45 minutes). All patients were successfully extubated on the day of ESD. No serious adverse events (AEs) related to WPM-ESDs were observed. None of the patients required nasogastric intubation, percutaneous endoscopic gastrostomy, or tracheotomy. The median fasting time and hospital stay were 2 days (range 2-5 days) and 6 days (range 6-10 days), respectively. All the histological results indicated squamous cell carcinoma. The complete histologic resection rate was 76.2%. Conclusions WPM-ESD achieved a high en bloc resection rate and short procedure time without serious AEs. Thus, it may be a useful treatment for pharyngeal lesions.

Potential for expanded application of endoscopic hand suturing: A pilot study of 15 cases.

Endoscopic hand suturing (EHS) was first developed to firmly close a mucosal defect following endoscopic submucosal dissection and has the potential for expanded applications. This study aimed to investigate the feasibility and safety of EHS in various clinical settings. In this single-center pilot study, 15 patients who had diseases with potential indications for EHS were prospectively recruited. Technical success, clinical success after the procedure, and severe EHS-related adverse events (AEs) were evaluated. EHS was applied for defect closure after gastric subepithelial lesion removal under laparoscopic observation (n = 9), defect closure after rectal endoscopic full-thickness resection (EFTR) (n = 2), defect closure after thoracoscopy-assisted esophageal EFTR (n = 1), mucosal closure for gastric ulcer bleeding (n = 1), mucosal closure after peroral endoscopic myotomy (POEM) (n = 1), and postoperative anastomotic leak (n = 1). EHS was completed without severe AEs and the clinical courses were also favorable in 13 patients (87%). The median suturing time was 61 minutes. In patients with POEM and anastomotic leak, EHS was discontinued because of the narrow lumen. In conclusion, EHS appears feasible and safe in situations.

Verification of the increase in concomitant dysplasia and cancer with the size of sessile serrated lesions.

Background and study aims This study aimed to evaluate the relationship between sessile serrated lesion (SSL) size and the comorbidity rate of SSL with dysplasia (SSLD) and cancer in SSL (SSL-cancer). Patients and methods This retrospective, single-center analysis identified SSL cases that underwent endoscopic resection between January 2015 and December 2022. The prevalence of SSL, SSLD, and SSL-cancer and their annual trends were assessed. The tumor diameter was stratified as 0 to 5 mm, 6 to 9 mm, 10 to 19 mm, and ≥ 20 mm in size. Furthermore, the frequency of SSL-D/SSL-cancer was determined in each group. Results The prevalence of SSL was 2.9% (1328/45799). This prevalence was 1.8% (112/6192) in 2015 and 4.2% (230/5500) in 2022, indicating an increasing trend over time. A total of 1825 lesions were assessed: 1751 (96.0%), 55 (3.0%), 14 (0.8%), and 5 (0.3%) of lesions were SSL, SSL with low-grade dysplasia, SSL with high-grade dysplasia and SSL-cancer, respectively. Stratifying the SSLs by size: 0 to 5 mm, 5 to 9 mm, 10 to 19 mm, and ≥ 20 mm, SSLD and SSL-cancer rates were 2.3% (10/429), 2.4% (16/674), 5.3% (31/584), and 11.8% (16/136), respectively. SSLD and SSL-cancer were observed in 2.4% (26/1103) of small SSLs < 10 mm. Conclusions In cases of SSL, the rate of SSLD and SSL-cancer increased as the lesion diameter increased. A certain rate of SSLD and SSL-cancer was observed even in small SSLs less than 5mm.

Gel immersion endoscopic mucosal resection for early gastric neoplasms: a multicenter case series study.

Several cases have been reported that suggest the efficacy of gel immersion endoscopic mucosal resection (GI-EMR) for gastric neoplasms. However, no study has evaluated treatment outcomes of GI-EMR for gastric neoplasms. This study aimed to investigate the efficacy and safety of GI-EMR for early gastric neoplasms. Nine patients (17 lesions) undergoing gastric GI-EMR were included, with a median lesion size of 10 mm (interquartile range [IQR] 5-13 mm). All lesions were protruding or flat elevated. The median procedure time was 3 minutes (IQR 2-5) and en bloc resection was achieved in all cases. Among 15 neoplastic lesions, the R0 resection rate was 86.7% (13/15 lesions). Adverse events included immediate bleeding requiring hemostasis in two cases, which was controlled endoscopically. No delayed bleeding or perforation occurred. In conclusion, GI-EMR may be a safe and effective treatment for early, small gastric neoplasms. However, due to the small sample in the present study, further investigation is required regarding the indication for this technique.

Through-the-scope clip retention rates and performance in a porcine model.

Background and study aims Limited comparative data exist to guide optimal through-the-scope (TTS) clip selection. The aim of this study was to compare the efficacy, retention, and safety of three industry-leading TTS clips on tissue that mimics common clinical scenarios. Methods A survival study involving six domestic pigs was undertaken. Three commonly used clip models were selected: Assurance (STERIS, Mentor, Ohio, United States), Resolution (Boston Scientific, Boston, Massachusetts, United States), and SureClip (Micro-Tech, Ann Arbor, Michigan, United States). To mimic clinical practice, the following scenarios were assessed: (1) normal mucosa; (2) cold snare resection; and (3) hot mucosal resection simulating fibrotic ulcers. Deployment of clips was randomized to target sites. Repeat endoscopy was performed 2 weeks following placement. Endoscopists rated the ease of use of clip placement on a Likert scale of 1 to 5. Results Fifty-four clips (18 Assurance, 18 Resolution, and 18 SureClip) were placed in six pigs. Mucosal healing was noted at all sites on follow up. Overall retention was nine of 18 (50.0%) SureClip, 10 of 18 (55.6%) Assurance, and 13 of 18 (72.2%) Resolution ( P =0.369). There was no difference in clip retention on normal and cold snare resection sites; however, clip retention was significantly higher for Resolution clips on fibrotic ulcers (50.0% versus 0% for Assurance and 0% SureClip, P =0.03). No adverse events were reported. Ease of use was equivalent across all models. Conclusions All clips were equivalent in efficacy and safety with successful clip deployment and mucosal healing. Overall retention rate was low for fibrotic tissue, with an improved retention rate observed with Resolution clips.

Effectiveness and safety of thin vs. thick cold snare polypectomy of small colorectal polyps: Systematic review and meta-analysis.

Background and study aims Cold-snare polypectomy (CSP) is considered the standard of care for resection of colorectal polyps ≤10 mm. Data on the efficacy of CSP performed with thin-wire snares compared0 with thick-wire snares are conflicting. We performed a meta-analysis comparing complete resection (CR) and adverse event rates of CSP using thin-wire and thick-wire snares. Patients and methods Comparative studies of adult patients with ≧1 colorectal polyp(s) ≦10 mm who underwent CSP with thin-wire or thick-wire snares were included. We collected data on study, patient, polyp, and snare characteristics. The primary outcome was CR rate. Secondary outcomes were polyp retrieval rate, intraprocedural bleeding, delayed post-polypectomy bleeding, deep mural injury or perforation, patient discomfort, total sedation, and procedure time. We used random-effects models to calculate risk ratios for outcomes. We performed risk of bias assessments, rated the certainty of evidence, and assessed publication bias for all studies. Results We included four randomized controlled trials (RCTs) and two observational studies including 1316 patients with 1679 polyps (826 thin-wire CSPs and 853 thick-wire CSPs). There was no significant difference between thin-wire CSP (92.1%) and thick-wire CSP (87.7%) for RCTs (risk ratio [RR] 1.05, 95% confidence interval [CI] 0.94-1.16) or observational studies (78.1% versus 79.6%, RR 1.03, 95% CI 0.99-1.08). There were no significant differences in polyp retrieval rate or intraprocedural bleeding. There were no cases of delayed bleeding or perforation. Conclusions We found no differences in CR rates for CSP between thin-wire and thick-wire snares. CSP, regardless of snare type, is safe and effective for resection of small colorectal polyps.