Non-pedunculated Colorectal Polyps Research Articles

Evaluation of the safety and feasibility of outpatient colorectal endoscopic submucosal dissection

Background and AimsEndoscopic submucosal dissection (ESD) is increasingly utilized for resection of benign nonpedunculated colorectal polyps and early cancers. However, there is concern that adoption of ESD may be limited by increased resource utilization with routine post-procedure admission. As endoscopic closure of ESD wounds has improved, in 2022 we adopted an outpatient colorectal ESD protocol. MethodsThis study was a retrospective evaluation of adult patients that underwent colorectal ESD from 1/2022 to 4/2023. When technically feasible, the wound was closed by clips or suturing. Following the procedure, patients were observed for up to 2 hours and discharged if they had no abdominal pain and there was no intra-operative muscle injury. We evaluated for operative success (en bloc resection, R0 and curative resection) as well as safety (post-procedure pain, perforation, delayed bleeding). ResultsA total of 111 lesions were removed by ESD in 105 consecutive patients. 19/111 (17%) had prior endoscopic mucosal resection. All lesions were successfully removed: en bloc resection rate was 93%, R0 and curative resection rate was 90%. 99/111 (89%) of the wounds were closed, most commonly using clips (60/111; 54%). There were two small intraprocedural perforations, both managed with clip closure and the patients did not require admission. Among patients with defect closure, there were no delayed bleeds requiring hospitalization and only 1 episode of self-limited bleeding. In contrast, among 12 patients with resection sites not amenable to closure, there was 1 delayed bleed requiring hospitalization, 2 minor bleeds assessed at the emergency department and 2 self-limited bleeds. ConclusionsIn this retrospective study we demonstrate the feasibility of outpatient colorectal ESD. Among 105 patients, only 2 required hospital admission: one for post-procedure pain and one for delayed bleeding. We find that after endoscopic closure of ESD wounds, hospital admission is generally unnecessary and significant post-procedure bleeding is rare.

Cold versus hot snare endoscopic mucosal resection for large (≥15 mm) flat non-pedunculated colorectal polyps: a randomised controlled trial

Background and aimsConventional hot snare endoscopic mucosal resection (H-EMR) is effective for the management of large (≥20 mm) non-pedunculated colon polyps (LNPCPs) however, electrocautery-related complications may incur significant morbidity. With...

Low-power pure-cut hot snare polypectomy for colorectal polyps 10-14mm in size: a multicenter retrospective study.

Hot snare excision using electrocautery is widely used for large colorectal polyps (>10mm); however, adverse events occur due to deep thermal injury. Colorectal polyps measuring 10-14mm rarely include invasive cancer. Therefore, less invasive therapeutic options for this size category are demanding. We have developed hot snare polypectomy with low-power pure-cut current (LPPC HSP), which is expected to contribute to less deep thermal damage and lower risk of adverse events. This study aimed to evaluate the efficacy and safety of LPPC HSP for 10-14mm colorectal polyps, compared with conventional endoscopic mucosal resection (EMR). In this multicenter, retrospective, observational study, clinical outcomes of EMR and LPPC HSP for 10-14mm nonpedunculated colorectal polyps between January 2021 and March 2022 were compared using propensity score matching. We identified 203 EMR and 208 LPPC HSP cases. After propensity score matching, the baseline characteristics between the groups were comparable, with 120 pairs. The en bloc and R0 resection rates were not significantly different between EMR and LPPC HSP groups (95.8% vs 97.5%, P=0.72; 90.0% vs 91.7%, P=0.82). The rates of delayed bleeding and perforation did not differ between the groups. Compared with conventional EMR, LPPC HSP showed a similar resection ability without an increase in adverse events. These results suggest that LPPC HSP is a safe and effective treatment for 10-14mm nonpedunculated colorectal polyps.

Safety and efficacy of low-power pure-cut hot snare polypectomy for small nonpedunculated colorectal polyps compared with conventional resection methods: A propensity score matching analysis.

Cold snare polypectomy (CSP) is widely performed for small colorectal polyps. However, small colorectal polyps sometimes include high-grade adenomas or carcinomas that require endoscopic resection with electrocautery. This study aimed to evaluate the efficacy and safety of a novel resection technique, hot snare polypectomy with low-power pure-cut current (LPPC-HSP) for small colorectal polyps, compared with CSP and conventional endoscopic mucosal resection (EMR). Records of patients who underwent CSP, EMR, or LPPC-HSP for nonpedunculated colorectal polyps less than 10 mm between April 2021 and March 2022 were retrospectively evaluated. We analyzed and compared the treatment outcomes of CSP and EMR with those of LPPC-HSP using propensity score matching. After propensity score matching of 396 pairs, an analysis of CSP and LPPC-HSP indicated that LPPC-HSP had a significantly higher R0 resection rate (84% vs. 68%; p < 0.01). Delayed bleeding was observed in only two cases treated with CSP before matching. Perforation was not observed with either treatment. After propensity score matching of 176 pairs, an analysis of EMR and LPPC-HSP indicated that their en bloc and R0 resection rates were not significantly different (99.4% vs. 100%, p = 1.00; 79% vs. 81%, p = 0.79). Delayed bleeding and perforation were not observed with either treatment. The safety of LPPC-HSP was comparable to that of CSP. The treatment outcomes of LPPC-HSP were comparable to those of conventional EMR for small polyps. These results suggest that this technique is a safe and effective treatment for nonpedunculated polyps less than 10 mm.

Cold Versus Hot Snare Endoscopic Resection of Large Nonpedunculated Colorectal Polyps: Randomized Controlled German CHRONICLE Trial

Endoscopic mucosal resection (EMR) is standard therapy for nonpedunculated colorectal polyps ≥20 mm. It has been suggested recently that polyp resection without current (cold resection) may be superior to the standard technique using cutting/coagulation current (hot resection) by reducing adverse events (AEs), but evidence from a randomized trial is missing. In this randomized controlled multicentric trial involving 19 centers, nonpedunculated colorectal polyps ≥20 mm were randomly assigned to cold or hot EMR. The primary outcome was major AE (eg, perforation or postendoscopic bleeding). Among secondary outcomes, major AE subcategories, postpolypectomy syndrome, and residual adenoma were most relevant. Between 2021 and 2023, there were 396 polyps in 363 patients (48.2% were female) enrolled for the intention-to-treat analysis. Major AEs occurred in 1.0% of the cold group and in 7.9% of the hot group (P= .001; odds ratio [OR], 0.12; 95% CI, 0.03-0.54). Rates for perforation and postendoscopic bleeding were significantly lower in the cold group, with 0% vs 3.9% (P= .007) and 1.0% vs 4.4% (P= .040). Postpolypectomy syndrome occurred with similar frequency (3.1% vs 4.4%; P= .490). After cold resection, residual adenoma was found more frequently, with 23.7% vs 13.8% (P= .020; OR, 1.94; 95% CI, 1.12-3.38). In multivariable analysis, lesion diameter of ≥4 cm was an independent predictor both for major AEs (OR, 3.37) and residual adenoma (OR, 2.47) and high-grade dysplasia/cancer for residual adenoma (OR, 2.92). Cold resection of large, nonpedunculated colorectal polyps appears to be considerably safer than hot EMR; however, at the cost of a higher residual adenoma rate. Further studies have to confirm to what extent polyp size and histology can determine an individualized approach. German Clinical Trials Registry (Deutsches Register Klinischer Studien), Number DRKS00025170.

Management of complex colorectal lesions from the endoscopic tissue resection specialist perspective

Endoscopic resection (ER) is the standard of care for the management of large (≥20 mm) non-pedunculated colorectal polyps (LNPCP). Certain lesion characteristics increase the risk for incomplete ER, recurrence, harbouring submucosal invasive cancer and post ER adverse events. These include lesion location, morphology, difficult endoscopic access and prior attempts at resection. Such LNPCP are termed ‘complex’. Recognition of complexity is a crucial component of technique selection and resource allocation. Until recently, resection of complex lesions was dominated by surgery. Surgical resection of benign lesions is associated with prolonged hospital stay and post-operative recovery, stoma creation, post-operative complications and even death. Advances in ER techniques have enabled huge strides in the management of these lesions and is proven to be safer and more cost-effective than surgery.

Standardised training for endoscopic mucosal resection of large non-pedunculated colorectal polyps to reduce recurrence (*STAR-LNPCP study): a multicentre cluster randomised trial

ObjectiveEndoscopic mucosal resection (EMR) is the preferred treatment for non-invasive large (≥20 mm) non-pedunculated colorectal polyps (LNPCPs) but is associated with an early recurrence rate of up to 30%. We...

A127 ENDOSCOPIC MUCOSAL RESECTION WITH HYBRID-ARGON PLASMA ABLATION TO PREVENT RECURRENCE OF 20 MM NON-PEDUNCULATED COLORECTAL POLYPS: A MULTI-CENTER PROSPECTIVE CLINICAL STUDY

Abstract Background Endoscopic mucosal resection (EMR) is the mainstay of therapy for non-pedunculated colorectal polyps 20 mm or larger. Post EMR recurrence rates are about 15% if no margin ablation technique is used. Aims Study aim was to evaluate recurrence rates if hybrid Argon Plasma Coagulation ablation (h-APC) is routinely used after the EMR to ablate the margins, base and vessels. Methods A prospective multi-center study including adult patients (18-89 years) undergoing EMR of non-pedunculated colorectal polyps 20 mm or larger was conducted. h-APC was used to ablate all post EMR margins and to ablate the post EMR resection surface and visible submucosal vessels. The primary outcome was the biopsy proven recurrence rate at the first follow-up colonoscopy (4-6 months after EMR). All the resection sites were visually inspected, and biopsies were obtained from the EMR scar. Secondary outcomes included technical success and complication rates. Results A total of 220 EMRs were performed during the study for h-APC ablation of non-pedunculated colorectal polyps, with a size of ≥20 mm. The average size of the polyps included in the study was 35.7 mm (ranging from 20 mm to 100 mm). Among all resected polyps, 16.8% were sessile serrated lesions (SSL), while 66.3% were adenomas. Additionally, 4 cases of cancer were in the study. The application of hot snare EMR with h-APC ablation was technically successful and completed for all cases. The mean duration of the EMR procedure was 19.6 minutes, ranging from 2.3 to 103 minutes, while the mean duration of h-APC ablation was 6.4 minutes, ranging from 1 to 65 minutes. A total of 147 EMRs with follow up examination (57 EMR involving lesions 40mm or larger) are available currently. The overall recurrence rate was 1.3% (2 out of 147 cases). For cases where complete base ablation was achieved, there was a 0% recurrence rate, including lesions 40mm or larger. For lesions measuring 40mm or larger, the recurrence rate was 1.8% (1 out of 54 cases). Out of the 220 total EMRs conducted, perforations were observed in 0.9% (2 cases, managed conservatively with antibiotics only), and clinically significant bleeding occurred in 2.3% (5 cases). In particular, clinically significant bleeding was noted in 2.3% (4 out of 167 cases) of lesions without clipping and in 4.0% (4 out of 99 cases) for right-sided lesions without clipping. Conclusions In this multicenter study EMR in combination with h-APC demonstrated a high technical success rate with low complication rates and showed very low post EMR recurrence in the preliminary data analysis. Funding Agencies Erbe

A133 MARGIN THERMAL ABLATION WITH SNARE-TIP SOFT COAGULATION EFFECTIVELY MITIGATES RECURRENCE AFTER ENDOSCOPIC MUCOSAL RESECTION OF LARGE NON-PEDUNCULATED COLORECTAL POLYPS

Abstract Background Recurrence following endoscopic mucosal resection (EMR) historically occurs in approximately 15-20% of large (≥20 mm) non-pedunculated colorectal polyps (LNPCPs). Margin thermal ablation with snare-tip soft coagulation (STSC) of the post-EMR defect is an evidence-based modality to mitigate recurrence. However, international validation of margin thermal ablation outcomes is needed. Aims To evaluate the frequencies of endoscopic and histologic recurrence following margin thermal ablation with STSC for LNPCPs managed by EMR. Methods Consecutive patients ampersand:003E 18 years of age who underwent endoscopic resection for a LNPCP were enrolled in a prospective single center observation cohort study (clinicaltrials.gov ID: NCT05402696). Of those lesions which underwent successful EMR, margin STSC was applied systematically aiming to create at least a 2-3mm rim of completed ablated tissue (complete whitening). Recurrence was evaluated both endoscopically, using a standardized protocol for the post-EMR scar, and histologically. Results From 06/2022-09/2023, 335 LNPCPs were endoscopically resected, including 209 by EMR. Following successful EMR, 182 (87.1%) underwent margin STSC. Of these lesions, 49 LNPCPs in 46 patients were assessed at first surveillance colonoscopy. Margin STSC was complete for 44 (89.8%) lesions and incomplete for 5 (10.2%) due to difficult angulation/positioning (n=3) and ileocecal valve location (n=2). Median interval to first surveillance colonoscopy was 6 (IQR 6-7) months. There was no evidence of recurrence noted on endoscopy. Biopsy was performed in 44 (89.8%) with no evidence of histologic recurrence. Conclusions Thermal ablation of the defect margin with STSC effectively negates recurrence and should be considered standard of care following EMR. Funding Agencies None

A134 ENDOSCOPIC RESECTION IS EFFECTIVE FOR COMPLEX LARGE NON-PEDUNCULATED COLORECTAL POLYPS

Abstract Background Endoscopic resection is preferred for most large (≥20 mm) non-pedunculated colorectal polyps (LNPCPs) due to superior efficacy, safety, and cost-efficiency compared to surgery. However, endoscopic resection can be challenging due to anatomical location, lesion characteristics, and concomitant colonic disease; these complex LNPCPs (C-LNPCPs) historically have suboptimal outcomes compared to uncomplicated LNPCPs (UC-LNPCPs). Aims To compare the outcomes of C-LNPCPs to UC-LNPCPs following endoscopic resection. Methods Consecutive patients ampersand:003E 18 years of age who underwent endoscopic resection of a LNPCP were enrolled in a prospective single center observation cohort study (clinicaltrials.gov ID: NCT05402696). C-LNPCP were defined by at least one of the following criteria: involvement of the appendiceal orifice, ileocecal valve, or anorectal junction; previous resection attempt; ≥ 90% circumferential involvement; concomitant inflammatory bowel disease. All other lesions were classified as UC-LNPCPs. Performance was evaluated by technical success (all neoplastic tissue removed at index procedure), procedure-related adverse events (intra-procedural perforation, clinically significant post-endoscopic resection bleeding (CSPEB), delayed perforation, serositis), referral to surgery, and recurrence at first surveillance colonoscopy (SC1). Results From 06/2022-09/2023, 350 LNPCPs were referred for endoscopic resection and 335 were attempted (91 C-LNPCPs, 244 UC-LNPCPs). Median age was 68 years (IQR 62-74 years) and 144 (54.1%) were male. Median size was 30mm (IQR 20-40mm). Most lesions were adenomatous (63.7% C-LNPCPs, 64.8% UC-LNPCPs), with cancer identified in 3.3% and 4.9% of C-LNPCPs and UC-LNPCPs, respectively. EMR was the most common resection modality (62.6% C-LNPCPs vs. 64.8% UC-LNPCPs) with C-LNPCPs undergoing more ESD (17.6% vs. 7.0%) and less CSR (19.8% vs. 28.3%; p=0.011). Auxiliary modalities were more frequently used in C-LNPCPs (6.6% vs. 1.2% UC-LNPCPs; p=0.004). Technical success was 95.6% in C-LNPCPs compared to 99.2% in UC-LNPCPs (p=0.049). There was no significant difference between groups in the frequencies of adverse events. 17 LNPCPs (5.1%; 4 C-LNPCP, 13 UC-LNPCPs) underwent surgery (p=1.000). Of those LNPCPs assessed at SC1, there was 1 recurrence (1.0%) in the UC-LNPCP subgroup. Conclusions With site-specific technical modifications and mitigating strategies for procedural-related adverse events, endoscopic resection outcomes for C-LNPCPs are comparable to UC-LNPCPs. Funding Agencies None

A119 ACUTE COLONOC PSEUDO-OBSTRUCTION AFTER ENDOSCOPIC RESECTION OF A FULLY CIRCUMFERENTIAL LARGE NON-PEDUNCULATED COLORECTAL POLYP

Abstract Background Complex large non-pedunculated colorectal polyps (LNPCPs), including those involving the full circumference of the bowel, are now readily managed by minimally invasive endoscopic resection techniques. Established procedure-related adverse events include sedation related adverse events, deep mural injury, clinically significant post-resection bleeding, delayed perforation and serositis. An appreciation for potential procedure-related adverse events is critical to the effective implementation of these techniques. Aims To describe a case of acute colonic pseudo-obstruction after endoscopic resection of a fully circumferential LNPCP. Methods Case report and review of the literature Results A 91-year-old male with a history of atrial fibrillation, chronic kidney disease and suspected McKittrick-Wheelock syndrome underwent successful endoscopic mucosal resection (EMR) of a 100mm fully circumferential LNPCP in the sigmoid colon. Histopathology diagnosed a tubulovillous adenoma with high-grade dysplasia. After elective admission, he suffered from clinically significant post-EMR bleeding requiring 2 units of packed red blood cells. On post-operative day 1 he began to suffer from nausea, abdominal pain and obstipation. On examination, he was visibly distended. Abdominal X-ray revealed extensive gas-filled loops of small and large bowel with the absence of gas in the rectum. He was managed conservatively with nasogastric tube decompression. Total duration of hospital stay was 9 days. Conclusions Critical to the continued expansion of minimally invasive endoscopic resection techniques is an awareness for potential procedure-related adverse events. To our knowledge this is the first description of acute colonic pseudo-obstruction after endoscopic resection Funding Agencies None

A94 PRE-RESECTION OPTICAL EVALUATION RELIABLY DIFFERENTIATES BETWEEN SERRATED AND ADENOMATOUS LARGE NON-PEDUNCULATED COLORECTAL POLYPS

Abstract Background Modality selection between cold snare resection (CSR) and endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) is largely predicated on the ability to differentiate between serrated and adenomatous histopathology. While optical evaluation has modest accuracy for diminutive polyps, performance has not been evaluated for large non-pedunculated colorectal polyps (LNPCPs). Aims To evaluate the performance of pre-resection optical evaluation to differentiate between serrated and adenomatous LNPCPs. Methods Consecutive patients ampersand:003E 18 years of age who underwent endoscopic resection for a LNPCP were enrolled in a prospective single center observation cohort study (clinicaltrials.gov ID: NCT05402696). Pre-resection optical evaluation was performed using high-definition white-light and narrow-band imaging (NBI) with or without near-focus. The Japanese NBI Expert Team (JNET) classification was used to differentiate between serrated (JNET I) vs. adenomatous (JNET IIA, IIB) LNPCPs. Traditional serrated adenomas (TSAs) and cancers were excluded from analysis. Sensitivity, specificity, and accuracy were used to evaluate optical evaluation performance. Results From 06/2022-09/2023, 266 patients underwent 282 procedures for a total of 335 LNPCPs. Median size was 30mm (IQR 20-40mm). Histopathology identified 215 (64.2%) adenomatous, 91 (27.2%) serrated, 16 (4.8%) cancerous, and 13 (3.9%) other LNPCPs; including 5 TSAs. Of the 91 serrated lesions, 90 (98.9%) were predicted as serrated; sensitivity, specificity, and accuracy were 98.90% (95% CI 94.03-99.97), 99.53% (95% CI 97.44-99.99), 99.35% (95% CI 97.66-99.92), respectively. Of the 215 adenomatous lesions, 213 (99.1%) were predicted as adenomatous; sensitivity, specificity, and accuracy were 99.07% (95% CI 96.68-99.89), 98.90% (95% CI 94.03-99.97), 99.02% (95% CI 97.16-99.80), respectively. Conclusions Optical evaluation demonstrates excellent performance characteristics to differentiate between serrated and adenomatous LNPCPs; therefore, empowering endoscopists to reliably apply a selective resection algorithm between CSR, EMR and ESD. Funding Agencies None

Establishment of standards for the referral of large nonpedunculated colorectal polyps: an international expert consensus using a modified Delphi process

Resection of colorectal polyps has been shown to decrease the incidence and mortality of colorectal cancer. Large nonpedunculated colorectal polyps are often referred to expert centers for endoscopic resection, which requires relevant information to be conveyed to the therapeutic endoscopist to allow for triage and planning of resection technique. The primary objective of this study was to establish minimum expected standards for the referral of large non-pedunculated colonic polyps for potential endoscopic resection. A Delphi method was used to establish consensus on minimum expected standards for the referral of large colorectal polyps among a panel of international endoscopy experts. The expert panel was recruited through purposive sampling, and 3 rounds of surveys were conducted to achieve consensus. Quantitative and qualitative data were analyzed for each round. A total of 24 international experts from diverse continents participated in the Delphi study, resulting in consensus on 19 statements related to the referral of large colorectal polyps. The identified factors, including patient demographic characteristics, relevant medications, lesion factors, photodocumentation, and the presence of a tattoo, were deemed important for conveying the necessary information to therapeutic endoscopists. The mean scores for the statements, which were scored on a scale of 1 to 10, ranged from 7.04 to 9.29, with high percentages of experts considering most statements as a very high priority. Subgroup analysis according to continent revealed some variations in consensus rates among experts from different regions. The identified consensus statements can aid in improving the triage and planning of resection techniques for large colorectal polyps, ultimately contributing to the reduction of colorectal cancer incidence and mortality.

Results of the COLDWATER randomized controlled trial: enhanced performance of underwater cold snare polypectomy for colorectal polyps 5-10 mm, independent of endoscopist experience.

The wide range of R0 resection rates (R0RR) and incomplete resection rates (IRR) observed with conventional cold snare polypectomy (CCSP) emphasizes the necessity for technique enhancement. The COLDWATER study aimed to compare underwater cold snare polypectomy (UCSP) to CCSP for 5-10-mm colorectal polyps, focusing on comprehensive histopathological evaluation, efficacy, and safety. This was a randomized, single-blind, controlled trial comparing UCSP to CCSP for non-pedunculated colorectal polyps of size 5-10 mm. The primary outcome was to report differences in the muscularis mucosa resection ratio. The secondary outcomes focused on differences in depth of excision, R0-RR, IRR, en bloc resection rate, adverse events, and recurrence rate. The COLDWATER study found higher muscularis mucosa resection in UCSP (81.72±62.81% vs. CCSP: 72.33±22.33%, P=0.003) with comparable submucosa presence (UCSP: 16.6%, CCSP: 12.5%, P=0.25). UCSP showed better outcomes regarding IRR (3.5% vs. 8.5%, P=0.05) and en bloc resection (98% vs. 93.5%, P=0.04). In CCSP, expert endoscopists achieved higher R0RR than non-experts, while UCSP showed no significant difference in R0RR across endoscopist's experience levels. UCSP achieves a more extensive excision of the muscularis mucosa compared to CCSP, even though it does not attain a deeper excision. Additionally, UCSP shows a higher en bloc resection rate, with lower rates of IRR, and emerges as a promising technique for training inexperienced endoscopists in polypectomy, given its experience-independent success in achieving R0 resection.

Safety and efficacy of physician-administered balanced-sedation for the endoscopic mucosal resection of large non-pedunculated colorectal polyps.

Background and study aims Because of concerns about peri-procedural adverse events (AEs), guidelines recommend anesthetist-managed sedation (AMS) for long and complex endoscopic procedures. The safety and efficacy of physician-administered balanced sedation (PA-BS) for endoscopic mucosal resection (EMR) of large non-pedunculated colorectal polyps (LNPCPs) ≥20 mm is unknown. Patients and methods We compared PA-BS with AMS in a retrospective study of prospectively collected data from consecutive patients referred for management of LNPCPs (NCT01368289; NCT02000141). A per-patient propensity analysis was performed following a 1:2 nearest-neighbor (Greedy-type) match, based on age, gender, Charlson comorbidity index, and lesion size. The primary outcome was any peri-procedural AE, which included hypotension, hypertension, tachycardia, bradycardia, hypoxia, and new arrhythmia. Secondary outcomes were unplanned admissions, 28-day re-presentation, technical success, and recurrence. Results Between January 2016 and June 2020, 700 patients underwent EMR for LNPCPs, of whom 638 received PA-BS. Among them, the median age was 70 years (interquartile range [IQR] 62-76 years), size 35 mm (IQR 25-45 mm), and duration 35 minutes (IQR 25-60 minutes). Peri-procedural AEs occurred in 149 (23.4%), most commonly bradycardia (116; 18.2%). Only five (0.8%) required an unplanned sedation-related admission due to AEs (2 hypotension, 1 arrhythmia, 1 bradycardia, 1 hypoxia), with a median inpatient stay of 1 day (IQR 1-3 days). After propensity-score matching, there were no differences between PA-BS and AMS in peri-procedural AEs, unplanned admissions, 28-day re-presentation rates, technical success or recurrence. Conclusions Physician-administered balanced sedation for the EMR of LNPCPs is safe. Peri-procedural AEs are infrequent, transient, rarely require admission (<1%), and are experienced in similar frequencies to those receiving anesthetist-managed sedation.

Cold Endoscopic Mucosal Resection (c-EMR) of Nonpedunculated Colorectal Polyps ≥20mm: A Systematic Review and Meta-analysis.

There is increasing evidence that cold endoscopic mucosal resection (c-EMR) can effectively treat large colorectal polyps. We aim to appraise the current literature and evaluate outcomes following c-EMR for nonpedunculated colonic polyps ≥20mm. Major databases were searched. Primary outcomes included recurrence rate and adverse events. Meta-analysis was performed using a random-effects model. Nine articles were included in the final analysis, which included 817 patients and 1077 colorectal polyps. Average polyp size was 28.8 (±5.1) mm. The pooled recurrence rate of polyps of any histology at 4 to 6 months was 21.0% (95% CI: 9.0%-32.0%, P<0.001, I2=97.3, P<0.001). Subgroup analysis showed that recurrence was 10% for proximal lesions (95% CI: 0.0%-20.0%, P=0.054, I2=93.7%, P=0.054) and 9% for distal lesions (95% CI: 2.0%-21.0%, P=0.114, I2=95.8%, P=0.114). Furthermore, subgroup analysis showed that recurrence was 12% for adenoma (95% CI: 4.0%-19.0%, P=0.003, I2=98.0%, P=0.003), and 3% for sessile serrated polyps (95% CI: 1.0%-5.0%, P=0.002, I2=34.4%, P=0.002). Post-polypectomy bleeding occurred in 1% (n=8/817) of patients, whereas abdominal pain occurred in 0.2% (n=2/817) of patients. C-EMR for nonpedunculated colorectal polyps ≥20mm shows an excellent safety profile with a very low rate of delayed bleeding as well as significantly less recurrence for sessile serrated polyps than adenomas.

Improving the management and outcomes of complex non-pedunculated colorectal polyps at a regional hospital in British Columbia.

Colorectal cancer arises from precancerous lesions, primarily adenomatous and serrated polyps. Some polyps pose significant technical endoscopic challenges due to their size, location, and/or morphology. A standardized protocol for documentation and management of these polyps can optimize clinical outcomes. A Quality Improvement project compared patients with a complex polyp (non-pedunculated, > 2cm), for 12months prior and 12months after protocol introduction. Documentation and polyp management details were compared pre- and post-implementation using the Chi-square test. 69 patients were diagnosed with complex polyps prior to the protocol introduction and 72 after. 79% (112/141) of patients underwent endoscopic mucosal resections (EMR) locally, and 14.9% (21/141) underwent surgery locally. After protocol introduction, there was significant improvement in documentation of suspicious appearing polyps (21.7% to 47.2%, P = 0.001), luminal circumference (14.5% to 34.7%, P = 0.005), and management plans (87.0% to 97.2%, P = 0.023); other elements of documentation were similar. The number of patients reviewed at multidisciplinary conference (MDC) increased from 1 to 61% (P < 0.005). Patients rebooked in a 1h endoscopy time slot increased from 19 to 58% (P < 0.005), as did specific consent for EMR from 22 to 57% (P < 0.005). Among patients with polyps 3cm or greater (23 pre, 36 post), MDC review increased from 4 to 67% (P < 0.005), primary polypectomy decreased from 72 to 23% (P = 0.001), patients rebooked in a double endoscopy slot increased from 33 to 75% (P = 0.005), and specific consent increased from 39 to 75% (P = 0.014). There were less polyp recurrences (12/42 pre and 1/50 post) among the post-protocol cohort (P < 0.001). The introduction of a formalized protocol for complex polyp adjudication and management has led to improved documentation, multidisciplinary discussion, and optimal complex polyp management with dedicated time for EMR, particularly for polyps over 3cm. There is room for improvement, and this can be approached in a collaborative manner.

Endoscopic resection of large anastomotic polyps is safe and effective.

Large (≥20mm) adenomatous anastomotic polyps (LAAPs) are uncommon. Data pertaining to their prevalence, characteristics, and the efficacy of endoscopic resection (ER) are absent. A safe and effective strategy for ER would reduce morbidity and healthcare costs. Large nonpedunculated colorectal polyps of ≥20mm (LNPCPs) referred for ER were prospectively studied. Multiple data points were recorded including anastomotic location, polyp morphology, resection modality, complications, and technical success. Over 7 years until November 2022, 2629 lesions were referred. Of these, 10 (0.4%) were LAAPs (median size 35 mm [interquartile range (IQR) 30-40mm]). All LAAPs were removed by piecemeal endoscopic mucosal resection (EMR), most (n=9; 90%) in combination with cold-forceps avulsion with adjuvant snare-tip soft coagulation (CAST). On comparison of the LAAP group with the conventional LNPCP group, CAST was more commonly used (90% vs. 9%; P<0.001) and deep mural injury (DMI) type II was more frequent (40% vs. 11%, P=0.003); however, significant DMI (III-V) did not occur. At 6 month (IQR 5.25-6 months) surveillance, there was no recurrence in any of the 10 cases. There were no serious adverse events. LAAPs present unique challenges owing to their location overlying an anastomosis. Despite these challenges they can be safely and effectively managed endoscopically without recurrence at endoscopic follow-up.

Dietary restriction after cold snare polypectomy of colorectal polyp for prevention of delayed bleeding.

Cold snare polypectomy (CSP) for small colorectal polyps is a safe technique; however, there is little evidence on whether dietary restriction after CSP is essential. This study aimed to determine whether dietary restriction after CSP is necessary to prevent delayed bleeding. This is a randomized, controlled, non-inferiority trial conducted between November 2021 and March 2022. Patients with non-pedunculated small colorectal polyps (<10 mm) and who did not take anticoagulants were randomly allocated to two groups: (i) the normal diet (ND) group, and (ii) the low-residue diet (LRD) group. The ND group was instructed to eat anything after CSP, whereas the LRD group was advised to take LRD for 3 days after CSP. The primary endpoint was the occurrence of delayed major bleeding that needed endoscopic hemostasis. A total of 193 patients (average 57.5 years old, 51.9% male) were enrolled in the study. Subsequently, 97 and 96 patients were allocated to the ND and LRD group, respectively. The occurrence of delayed major bleeding was 1.0% in the ND group and 2.1% in the LRD group (95% confidence interval [CI]: -4.4% to 2.4%; difference: -1.1%), which showed the non-inferiority of the ND group. In addition, there was no difference between the two groups with respect to the occurrence of minor delayed bleeding (3.1% and 4.2%, respectively; difference: -1.1% [95% CI: -6.4% to 4.2%]). Dietary restriction after CSP for low-bleeding-risk colorectal polyps is not necessary for the prevention of delayed bleeding (Registration number: UMIN000045669).

Comments on: "Effect of pre-resection biopsy on detection of advanced dysplasia in large nonpedunculated colorectal polyps undergoing endoscopic mucosal resection".

Comments on: "Effect of pre-resection biopsy on detection of advanced dysplasia in large nonpedunculated colorectal polyps undergoing endoscopic mucosal resection".