Impact of margin thermal ablation after endoscopic mucosal resection of large (≥20 mm) non-pedunculated colonic polyps on long-term recurrence.

BACKGROUND AND AIMS: The efficacy of colorectal endoscopic mucosal resection (EMR) is limited by recurrence and the necessity for conservative surveillance. Margin thermal ablation (MTA) after EMR has reduced the incidence of recurrence at the first surveillance colonoscopy at 6 months (SC1). Whether this effect is durable to second surveillance colonoscopy (SC2) is unknown. We evaluated long-term surveillance outcomes in a cohort of LNPCPs that have undergone MTA. METHODS: LNPCPs undergoing EMR and MTA from four academic endoscopy centres were prospectively recruited. EMR scars were evaluated at SC1 and in the absence of recurrence, SC2 colonoscopy was conducted in a further 12 months. A historical control arm was generated from LNPCPs that underwent EMR without MTA. The primary outcome was recurrence at SC2 in all LNPCPs with a recurrence-free scar at SC1. RESULTS: 1152 LNPCPs underwent EMR with complete MTA over 90 months until October 2022. 854 LNPCPs underwent SC1 with 29/854 (3.4%) LNPCPs demonstrating recurrence. 472 LNPCPs free of recurrence at SC1 underwent SC2. 260 LNPCPs with complete SC2 follow-up formed the control arm from January 2012 to May 2016. Recurrence at SC2 was significantly less in the MTA arm versus controls (1/472 (0.2%) vs 9/260 (3.5%); p<0.001)). CONCLUSION: LNPCPs that have undergone successful EMR with MTA and are free of recurrence at SC1 are unlikely to develop recurrence in subsequent surveillance out to 2 years. Provided the colon is cleared of synchronous neoplasia, the next surveillance can be potentially extended to 3-5 years. Such an approach would reduce costs and enhance patient compliance.

Selection of endoscopic resection technique for large colorectal lesion treatment.

PURPOSE OF REVIEW: Large nonpedunculated colorectal polyps ≥ 20 mm (LNPCPs) comprise 1% of all colorectal lesions. LNPCPs are more likely to contain advanced histology such as high-grade dysplasia and submucosal invasive cancer (SMIC). Endoscopic resection is the first-line approach for management of these lesions. Endoscopic resection options include endoscopic mucosal resection (EMR), cold-snare EMR (EMR), endoscopic submucosal dissection (ESD) and endoscopic full-thickness resection (EFTR). This review aimed to critically evaluate current endoscopic resection techniques. RECENT FINDINGS: Evidence-based selective resection algorithms should inform the most appropriate endoscopic resection technique. Most LNPCPs are removed by conventional EMR but there has been a trend toward C-EMR for endoscopic resection of LNPCPs. More high-quality trials are required to better define the limitations of C-EMR. Advances in our understanding of ESD technique, has clarified its role within the colorectum. More recently, the development of a full thickness resection device (FTRD) has allowed the curative endoscopic resection of select lesions. SUMMARY: Endoscopic resection should be regarded as the principle approach for all LNPCPs. Underpinned by high-quality research, endoscopic resection has become more nuanced, leading to improved patient outcomes.

Prevalence of Endoscopically Curable Low-Risk Cancer Among Large (≥20 mm) Nonpedunculated Polyps in the Right Colon.

BACKGROUND AND AIMS: Endoscopic submucosal dissection is increasingly promoted for the treatment of all large nonpedunculated colorectal polyps (LNPCPs) to cure potential low-risk cancers (superficial submucosal invasion without additional high-risk histopathologic features). The effect of a universal en bloc strategy on oncologic outcomes for the treatment of LNPCPs in the right colon is unknown. We evaluated this in a large Western population. METHODS: A prospective cohort of patients referred for endoscopic resection (ER) of LNPCPs was analyzed. Patients found to have cancer after ER and those referred directly to surgery were included. The primary outcome was to determine the proportion of right colon LNPCPs with low-risk cancer. RESULTS: Over 180 months until June 2023, 3294 sporadic right colon LNPCPs in 2956 patients were referred for ER at 7 sites (median size 30 [interquartile range 22.5-37.5] mm). A total of 63 (2.1%) patients were referred directly to surgery, and cancer was proven in 56 (88.9%). A total of 2851 (96.4%) of 2956 LNPCPs underwent ER (median size 35 [interquartile range 25-45] mm), of which 75 (2.6%) were cancers. The overall prevalence of cancer in the right colon was 4.4% (n = 131 of 2956). Detailed histopathologic analysis was possible in 115 (88%) of 131 cancers (71 after ER, 44 direct to surgery). After excluding missing histopathologic data, 23 (0.78%) of 2940 sporadic right colon LNPCPs were low-risk cancers. CONCLUSIONS: The proportion of right colon LNPCPs referred for ER containing low-risk cancer amenable to endoscopic cure was <1%, in a large, multicenter Western cohort. A universal endoscopic submucosal dissection strategy for the management of right colon LNPCPs is unlikely to yield improved patient outcomes given the minimal impact on oncologic outcomes. CLINICALTRIALS: gov, Numbers: NCT01368289, NCT02000141.

A subepithelial lesion algorithm for endoscopic (SAFE) resection in the upper gastrointestinal tract.

BACKGROUND: Complete excision of upper gastrointestinal subepithelial lesions (U-SELs) eliminates diagnostic uncertainty, obviates the need for surveillance, and may be necessary for definitive diagnosis and management. Current guidelines lack precision and cohesion, and surgery is associated with significant morbidity. We describe and report on the outcomes of our SEL algorithm for endoscopic (SAFE) resection. METHODS: U-SELs were enrolled prospectively over 115 months until March 2023. All subjects underwent axial (computed tomography) imaging and endoscopic ultrasonography (EUS) to exclude a large exophytic component or invasion into local structures, and assess for muscularis propria (MP) involvement. RESULTS: 106 U-SELs (41 esophageal, 65 gastric) were resected (mean patient age 60.6 [SD 13.4]; 51.9% male). Esophageal U-SELs underwent endoscopic submucosal dissection (ESD; n = 22) or submucosal tunneling endoscopic resection (STER) if MP involvement was suspected (n = 19). Gastric U-SELs underwent STER (n = 6 at cardia), ESD (n = 47), or exposing endoscopic full-thickness resection (e-EFTR; n = 12). Technical success rates were 97.6% and 92.3%, respectively. Among the noncardiac gastric U-SELs, five resections (9.6%) were completed laparoscopically owing to deep and broad full-thickness involvement; five (9.6%) required laparoscopic gastrotomy and surgical retrieval after successful resection and closure owing to a large lesion size (mean 47 mm). There was no delayed bleeding, perforation, or recurrence at 13 months. CONCLUSION: U-SELs may be effectively and safely treated by endoscopic resection. The SAFE approach provides a framework that facilitates structured decision-making. Esophageal U-SELs suspected of involving the MP should undergo STER. Gastric SELs are best managed by ESD, with a view to proceeding to e-EFTR. A laparoscopic upper gastrointestinal surgeon should be available in case surgical retrieval of the specimen or laparoscopic completion is required.

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

BACKGROUND AND AIMS: Conventional 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 a superior safety profile, cold snare EMR (C-EMR) of LNPCPs is an attractive alternative however evidence is lacking. We conducted a randomised trial to compare the efficacy and safety of C-EMR to H-EMR. METHODS: Flat, 15-50 mm adenomatous LNPCPs were prospectively enrolled and randomly assigned to C-EMR or H-EMR with margin thermal ablation at a single tertiary centre. The primary outcome was endoscopically visible and/or histologically confirmed recurrence at 6 months surveillance colonoscopy. Secondary outcomes were clinically significant post-EMR bleeding (CSPEB), delayed perforation and technical success. RESULTS: 177 LNPCPs in 177 patients were randomised to C-EMR arm (n=87) or H-EMR (n=90). Treatment groups were equivalent for technical success 86/87 (98.9%) C-EMR versus H-EMR 90/90 (100%); p=0.31. Recurrence was significantly greater in C-EMR (16/87, 18.4% vs 1/90, 1.1%; relative risk (RR) 16.6, 95% CI 2.24 to 122; p<0.001).Delayed perforation (1/90 (1.1%) vs 0; p=0.32) only occurred in the H-EMR group. CSPEB was significantly greater in the H-EMR arm (7/90 (7.8%) vs 1/87 (1.1%); RR 6.77, 95% CI 0.85 to 53.9; p=0.034). CONCLUSION: Compared with H-EMR, C-EMR for flat, adenomatous LNPCPs, demonstrates superior safety with equivalent technical success. However, endoscopic recurrence is significantly greater for cold snare resection and is currently a limitation of the technique. TRIAL REGISTRATION NUMBER: NCT04138030.

Long-term outcomes after endoscopic submucosal dissection for relative indication early gastric cancer in nonsurgical candidates.

BACKGROUND AND AIMS: Endoscopic submucosal dissection (ESD) is effective in treating early gastric cancer (EGC). Its role in patients with comorbidities along with more advanced disease is unknown. We sought to evaluate this in a large Western cohort. METHODS: Consecutive patients who underwent ESD for EGC in a single tertiary Western endoscopy center over 10 years were prospectively analyzed. The primary outcomes were long-term overall survival (OS) and disease-free survival (DFS) up to 5 years. Secondary outcomes were efficacy and serious adverse events (SAEs). RESULTS: ESD for 157 cases of EGC in 149 patients was performed in an elderly and comorbid cohort with a mean age of 73.7 years and age-adjusted Charlson Comorbidity Index of 4.2. Over a median follow-up of 51.6 months, no significant differences were found in 5-year OS (88.9% vs 77.9%, P = .290) and DFS (83.2% vs 75.1%, P = .593) between absolute indication EGC and relative indication (RI) EGC. The absolute indication EGC cohort achieved higher en bloc (96.3% vs 87.5%, P = .069) and R0 resection rates (93.6% vs 62.5%, P < .001) when compared with RI EGC. No significant differences were found in SAEs (7.3% vs 12.5%, P = .363). No mortality or surgical resection ensued from adverse events from ESD. CONCLUSIONS: ESD safely confers DFS in poor surgical candidates with RI EGC in a large Western cohort. Patients who are elderly and/or with comorbidities or who decline surgical resection may benefit from ESD and avoid the risks of surgery and its long-term sequelae. (Clinical trial registration number: NCT02306707.).

A simplified algorithm to evaluate the risk of submucosal invasive cancer in large (≥20 mm) nonpedunculated colonic polyps.

BACKGROUND: Recognition of submucosal invasive cancer (SMIC) in large (≥20 mm) nonpedunculated colonic polyps (LNPCPs) informs selection of the optimal resection strategy. LNPCP location, morphology, and size influence the risk of SMIC; however, currently no meaningful application of this information has simplified the process to make it accessible and broadly applicable. We developed a decision-making algorithm to simplify the identification of LNPCP subtypes with increased risk of potential SMIC. METHODS: Patients referred for LNPCP resection from September 2008 to November 2022 were enrolled. LNPCPs with SMIC were identified from endoscopic resection specimens, lesion biopsies, or surgical outcomes. Decision tree analysis of lesion characteristics identified in multivariable analysis was used to create a hierarchical classification of SMIC prevalence. RESULTS: 2451 LNPCPs were analyzed: 1289 (52.6%) were flat, 1043 (42.6%) nodular, and 118 (4.8%) depressed. SMIC was confirmed in 273 of the LNPCPs (11.1%). It was associated with depressed and nodular vs. flat morphology (odds ratios [ORs] 35.7 [95%CI 22.6-56.5] and 3.5 [95%CI 2.6-4.9], respectively; P<0.001); rectosigmoid vs. proximal location (OR 3.2 [95%CI 2.5-4.1]; P<0.001); nongranular vs. granular appearance (OR 2.4 [95%CI 1.9-3.1]; P<0.001); and size (OR 1.12 per 10-mm increase [95%CI 1.05-1.19]; P<0.001). Decision tree analysis targeting SMIC identified eight terminal nodes: SMIC prevalence was 62% in depressed LNPCPs, 19% in nodular rectosigmoid LNPCPs, and 20% in nodular proximal colon nongranular LNPCPs. CONCLUSIONS: This decision-making algorithm simplifies identification of LNPCPs with an increased risk of potential SMIC. When combined with surface optical evaluation, it facilitates accurate lesion characterization and resection choices.

When less is more: lower esophageal sphincter-preserving peroral endoscopic myotomy is effective for non-achalasia esophageal motility disorders.

BACKGROUND: Non-achalasia esophageal motility disorders (NAEMDs), encompassing distal esophageal spasm (DES) and hypercontractile esophagus (HCE), are rare conditions. Peroral endoscopic myotomy (POEM) is a promising treatment option. In NAEMDs, unlike with achalasia, the lower esophageal sphincter (LES) functions normally, suggesting the potential of LES preservation during POEM. METHODS: This retrospective two-center observational study focused on patients undergoing LES-preserving POEM (LES-POEM) for NAEMD. Eckardt scores were assessed pre-POEM and at 6, 12, and 24 months post-POEM, with follow-up endoscopy at 6 months to evaluate for reflux esophagitis. Clinical success, defined as an Eckardt score ≤3, served as the primary outcome. RESULTS: 227 patients were recruited over 84 months until May 2021. Of these, 16 underwent LES-POEM for an NAEMD (9 with HCE and 7 with DES). The median pre-POEM Eckardt score was 6.0 (interquartile range [IQR] 5.0-7.0), which decreased to 1.0 (IQR 0.0-1.8; P<0.001) 6 months post-POEM. This was sustained at 24 months, with an Eckardt score of 1.0 (IQR 0.0-1.8; P<0.001). Two patients (12.5%) developed Los Angeles grade A or B esophagitis. CONCLUSIONS: LES-POEM for NAEMD demonstrates favorable clinical outcomes, with infrequent esophagitis and reintervention for LES dysfunction rarely required.

Direct diverticular peroral endoscopic myotomy for the treatment of thoracic esophageal diverticula: technique and outcomes.

BACKGROUND: Diverticular peroral endoscopic myotomy (POEM) is an alternative to surgery for the management of symptomatic thoracic esophageal diverticula. Conventionally, this requires proximal tunnel formation but a direct approach may simplify the technique. Herein, we report the outcomes of direct diverticular-POEM (DD-POEM). METHODS: We conducted a single-center prospective observational study evaluating DD-POEM. This involved a direct approach to the diverticulum. Success was defined as an Eckardt score of ≤ 3 without the need for reintervention. RESULTS: 10 patients underwent DD-POEM (median age 72 years; interquartile range [IQR] 14.3; male 60 % [n = 6]). Median diverticulum size was 40 mm (IQR 7.5) and median location was 35 cm from the incisors (IQR 8.3). Five patients (50 %) had an underlying dysmotility disorder. The median procedure duration was 60 minutes (IQR 28.8). There were no adverse events. The median hospital stay was 1 day (IQR 0.75). The pre-procedure median Eckardt score of 6 (IQR 4) significantly improved to 0 (IQR 0.75; P < 0.001) at a median follow-up of 14.5 months (IQR 13.8). Success was achieved in all patients. CONCLUSIONS: DD-POEM was a safe technique for the management of thoracic esophageal diverticula. Owing to its simplicity and excellent performance it should be further evaluated for the treatment of this disorder.

Hybrid resection versus conventional resection for laterally spreading lesions of the papilla.

BACKGROUND AND AIMS: Although conventional hot snare resection (CR) of laterally spreading lesions of the major papilla (LSL-Ps) is effective, it can be associated with delayed bleeding in upward of 25% of cases. Given the excellent safety profile of cold snare polypectomy in the colorectum, we investigated the efficacy and safety of a novel hybrid resection (HR) technique for LSL-P management, consisting of hot snare papillectomy plus cold snare resection of the laterally spreading component. METHODS: A prospective cohort of patients underwent HR in a tertiary referral center over 60 months until December 2022. This cohort was compared with a historical cohort of patients who underwent CR at the same institution over 120 months until August 2017. The primary outcomes were recurrence and bleeding. RESULTS: Twenty patients underwent HR (14 female; mean age 65.2 ± 12.2 years). Median lesion size was 30 mm (interquartile range, 25.0-47.5 mm). Recurrent or residual adenoma (RRA) was greater with HR (58.8% [n = 10] vs 29.8% [n = 14]; P = .034). The odds ratio for recurrence was 3.6 times (95% CI, 1.2-11.0) higher with HR (P = .027). RRA was multifocal in 4 (40%) and had a composite RRA volume >10 mm in 7 (70%). The median number of procedures required to treat RRA was higher with HR (4 vs 1, P = .002). There was no difference between CR and HR for intraprocedural bleeding (41.1% [n = 23] vs 25% [n = 5]; P = .587) or delayed bleeding (25.0% vs 10.0%, P = .211). There were no perforations. CONCLUSIONS: The novel HR technique for LSL-P management is associated with a high rate of RRA that is recalcitrant to treatment, without mitigating the risk of intraprocedural or delayed bleeding. Therefore, CR should remain the mainstay management option for treating patients with an LSL-P. (Clinical trial registration number: NCT02306603.).

Geometry of cold snare polypectomy and risk of incomplete resection.

BACKGROUND: Cold snare polypectomy (CSP) is safer than and equally efficacious as hot snare polypectomy (HSP) for the removal of small (<10mm) colorectal polyps. The maximum polyp size that can be effectively managed by piecemeal CSP (p-CSP) without an excessive burden of recurrence is unknown. METHODS: Resection error risks (RERs), defined as the estimated likelihood of incomplete removal of adenomatous tissue for a single snare resection pass, for CSP and HSP were calculated, based on an incomplete resection rate. Polyp area, snare size, estimated number of resections, and optimal resection defect area were modeled. Overall risk of incomplete resection (RIR) was defined as RIR=1 - (1 - p)n, where p is the RER and n the number of resections. RESULTS: A 40-mm polyp has a four times greater area than a 20-mm polyp (314.16mm2 vs. 1256.64mm2), and requires three times more resections (11 vs. 33, respectively, assuming 8-mm piecemeal resection pieces for p-CSP). RIRs for a 40-mm polyp by HSP and p-CSP were 15.1%-23% and 40.74%-60.60% respectively. CONCLUSION: RER is more important with p-CSP than with HSP. The number of resections, n, and consequently RIR increases with increasing polyp size. Given the overwhelming safety of CSP, specific techniques to minimize the RER should be studied and developed.

Endoscopic resection of large anastomotic polyps is safe and effective.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Endoscopic Management of Large Non-Pedunculated Colorectal Polyps.

Large non-pedunculated colorectal polyps ≥20 mm (LNPCPs) comprise approximately 1% of all colorectal polyps. LNPCPs more commonly contain high-grade dysplasia, covert and overt cancer. These lesions can be resected using several means, including conventional endoscopic mucosal resection (EMR), cold-snare EMR (C-EMR) and endoscopic submucosal dissection (ESD). This review aimed to provide a comprehensive, critical and objective analysis of ER techniques. Evidence-based, selective resection algorithms should be used when choosing the most appropriate technique to ensure the safe and effective removal of LNPCPs. Due to its enhanced safety and comparable efficacy, there has been a paradigm shift towards cold-snare polypectomy (CSP) for the removal of small polyps (<10 mm). This technique is now being applied to the management of LNPCPs; however, further research is required to define the optimal LNPCP subtypes to target and the viable upper size limit. Adjuvant techniques, such as thermal ablation of the resection margin, significantly reduce recurrence risk. Bleeding risk can be mitigated using through-the-scope clips to close defects in the right colon. Endoscopic surveillance is important to detect recurrence and synchronous lesions. Recurrence can be readily managed using an endoscopic approach.

A novel tool for case selection in endoscopic mucosal resection training.

BACKGROUND: As endoscopic mucosal resection (EMR) of large (≥ 20 mm) adenomatous nonpedunculated colonic polyps (LNPCPs) becomes widely practiced outside expert centers, appropriate training is necessary to avoid failed resection and inappropriate surgical referral. No EMR-specific tool guides case selection for endoscopists learning EMR. This study aimed to develop an EMR case selection score (EMR-CSS) to identify potentially challenging lesions for "EMR-naïve" endoscopists developing competency. METHODS: Consecutive EMRs were recruited from a single center over 130 months. Lesion characteristics, intraprocedural data, and adverse events were recorded. Challenging lesions with intraprocedural bleeding (IPB), intraprocedural perforation (IPP), or unsuccessful resection were identified and predictive variables identified. Significant variables were used to form a numerical score and receiver operating characteristic curves were used to generate cutoff values. RESULTS: Of 1993 LNPCPs, 286 (14.4 %) were in challenging locations (anorectal junction, ileocecal valve, or appendiceal orifice), 368 (18.5 %) procedures were complicated by IPB and 77 (3.9 %) by IPP; 110 (5.5 %) procedures were unsuccessful. The composite end point of IPB, IPP, or unsuccessful EMR was present in 526 cases (26.4 %). Lesion size, challenging location, and sessile morphology were predictive of the composite outcome. A six-point score was generated with a cutoff value of 2 demonstrating 81 % sensitivity across the training and validation cohorts. CONCLUSIONS: The EMR-CSS is a novel case selection tool for conventional EMR training, which identifies a subset of adenomatous LNPCPs that can be successfully and safely attempted in early EMR training.

Endoscopic resection-related colorectal strictures: risk factors, management, and long-term outcomes.

INTRODUCTION: Colorectal strictures related to endoscopic resection (ER) of large nonpedunculated colorectal polyps (LNPCPs) may be problematic. Data on prevalence, risk factors, and management are limited. We report a prospective study of colorectal strictures following ER and describe our approach to management. METHODS: We analyzed prospectively collected data over 150 months, until June 2021, for patients who underwent ER for LNPCPs ≥ 40 mm. The ER defect size was graded as < 60 %, 60 %-89 %, or ≥ 90 % of the luminal circumference. Strictures were considered "severe" if patients experienced obstructive symptoms, "moderate" if an adult colonoscope could not pass the stenosis, or "mild" if there was resistance on successful passage. Primary outcomes included stricture prevalence, risk factors, and management. RESULTS: 916 LNPCPs ≥ 40 mm in 916 patients were included (median age 69 years, interquartile range 61-76 years, male sex 484 [52.8 %]). The primary resection modality was endoscopic mucosal resection in 859 (93.8 %). Risk of stricture formation with an ER defect ≥ 90 %, 60 %-89 %, and < 60 % was 74.2 % (23/31), 25.0 % (22/88), and 0.8 % (6 /797), respectively. Severe strictures only occurred with ER defects ≥ 90 % (22.6 %, 7/31). Defects < 60 % conferred low risk of only mild strictures (0.8 %, 6/797). Severe strictures required earlier (median 0.9 vs. 4.9 months; P = 0.01) and more frequent (median 3 vs. 2; P = 0.02) balloon dilations than moderate strictures. CONCLUSION: Most patients with ER defects ≥ 90 % of luminal circumference developed strictures, many of which were severe and required early balloon dilation. There was minimal risk with ER defects < 60 %.

The Surface Morphology of Large Nonpedunculated Colonic Polyps Predicts Synchronous Large Lesions.

BACKGROUND & AIMS: Large (≥20 mm) nonpedunculated colorectal polyps (LNPCPs) may have synchronous LNPCPs in up to 18% of cases. The nature of this relationship has not been investigated. We aimed to examine the relationship between individual LNPCP characteristics and synchronous colonic LNPCPs. METHODS: Consecutive patients referred for resection of LNPCPs over 130 months until March 2022 were enrolled. Serrated lesions and mixed granularity LNPCPs were excluded from analysis. Patients with multiple LNPCPs resected were identified, and the largest was labelled as dominant. The primary outcome was the identification of individual lesion characteristics associated with the presence of synchronous LNPCPs. RESULTS: There were 3149 of 3381 patients (93.1%) who had a single LNPCP. In 232 (6.9%) a synchronous lesion was detected. Solitary lesions had a median size of 35 mm with a predominant Paris 0-IIa morphology (42.9%) and right colon location (59.5%). In patients with ≥2 LNPCPs, the dominant lesion had a median size of 40 mm, Paris 0-IIa (47.6%) morphology, and right colon location (65.9%). In this group, 35.8% of dominant LNPCPs were non-granular compared with 18.7% in the solitary LNPCP cohort. Non-granular (NG)-LNPCPs were more likely to demonstrate synchronous disease, with left colon NG-LNPCPs demonstrating greater risk (odds ratio, 4.78; 95% confidence interval, 2.95-7.73) than right colon NG-LNPCPs (odds ratio, 1.99; 95% confidence interval, 1.39-2.86). CONCLUSIONS: We found that 6.9% of LNPCPs have synchronous disease, with NG-LNPCPs demonstrating a greater than 4-fold increased risk. With post-colonoscopy interval cancers exceeding 5%, endoscopists must be cognizant of an individual's LNPCP phenotype when examining the colon at both index procedure and surveillance. CLINICALTRIALS: gov, NCT01368289; NCT02000141; NCT02198729.

Cold snare EMR for the removal of large duodenal adenomas.

BACKGROUND AND AIMS: Large (≥15 mm) duodenal adenomas (DAs) are premalignant and require removal. Existing endoscopic resection techniques are compromised by serious adverse events (SAEs), most notably postprocedural bleeding (PPB) and perforation. To ameliorate these problems, we sought to evaluate the novel technique of cold snare EMR (CS-EMR) against the emerging standard of conventional EMR with thermal ablation of the postresection margin (EMR-T) for the safe and effective removal of DAs. METHODS: Consecutive patients were enrolled in a single tertiary center for CS-EMR and prospectively analyzed against a previously reported cohort of EMR-T from the same center. The primary outcome was rate of SAEs. Secondary outcomes were residual or recurrent adenoma at first surveillance endoscopy (SE1) at 6 months and technical success per lesion. RESULTS: Between October 2019 and July 2022, a total of 50 DAs ≥15 mm were removed via CS-EMR (median size, 30 mm [interquartile range (IQR), 19-40 mm]; mean ± standard deviation [SD] patient age, 70 ± 9.2 years) compared with 54 DAs via EMR-T (median size, 30 mm [IQR, 19-40 mm]; mean patient age, 68 ± 12.2 years). CS-EMR had a significantly lower rate of intraprocedural bleeding (2.0% vs 37%, P < .001) and PPB (4.0% vs 16.7%, P = .036). Two cases (4.0%) of immediate perforation occurred in CS-EMR; these were recognized immediately and closed with clips without sequelae. Total SAEs (16.0% vs 16.7%, P = 1) and technical success (100% vs 100%, P = 1) were identical. Recurrence at SE1 was significantly higher with CS-EMR (24.4% vs 2.3%, P = .002). CONCLUSIONS: CS-EMR reduces intraprocedural bleeding and PPB. However, it may increase the risk of immediate perforation and is associated with a significantly higher rate of recurrence at SE1. Further technical refinements are required to optimize endoscopic resection techniques for DAs. (Clinical trial registration number: NCT02306603.).

A Rectum-Specific Selective Resection Algorithm Optimizes Oncologic Outcomes for Large Nonpedunculated Rectal Polyps.

BACKGROUND AND AIMS: Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) are complementary techniques for large (≥20 mm) nonpedunculated rectal polyps (LNPRPs). A mechanism for appropriate technique selection has not been described. METHODS: We evaluated the performance of a selective resection algorithm (SRA) (August 2017 to April 2021) compared with a universal EMR algorithm (UEA) (July 2008 to July 2017) for LNPRPs within a prospective observational study. In the SRA, LNPRPs with features of superficial submucosal invasive cancer (SMIC) (<1000 µm; Kudo pit pattern Vi), or with an increased risk of SMIC (Paris 0-Is or 0-IIa+Is nongranular, 0-IIa+Is granular with a dominant nodule ≥10 mm) underwent ESD. The remaining LNPRPs underwent EMR. Algorithm performance was evaluated by SMIC identified after EMR, curative oncologic resection (R0 resection, superficial SMIC, absence of negative histologic features), technical success, adverse events, and recurrence at first surveillance colonoscopy. RESULTS: A total of 480 LNPRPs were evaluated (290 UEA, 190 SRA). Median lesion size was 40 (interquartile range, 30-60) mm. SMIC was identified in 56 (11.7%) LNPRPs. Significant differences in SMIC after EMR (SRA 1 [1.0%] vs UEA 35 [12.1%]; P = .001) and curative oncologic resection (SRA n = 7 [33.3%] vs UEA n = 2 [5.7%]; P = .010) were identified. No significant differences in technical success or adverse events were identified (all P > .137). Among LNPRPs with SMIC amenable to curative oncologic resection and which underwent ESD, 100% (n = 7 of 7) were cured. CONCLUSIONS: A rectum-specific SRA optimizes oncologic outcomes for LNPRPs and mitigates the risk of piecemeal resection of cancers.

Comparison of the morphology and histopathology of large nonpedunculated colorectal polyps in the rectum and colon: implications for endoscopic treatment.

BACKGROUND AND AIMS: The risk of cancer in large nonpedunculated colorectal polyps ≥20 mm (LNPCPs) in the rectum relative to the remainder of the colon is unknown. We aimed to describe differences between rectal and colonic LNPCPs to better inform treatment decisions. METHODS: Patients with LNPCPs referred to tertiary centers for endoscopic resection within a prospective, multicenter, observational cohort were evaluated. Data recorded were participant demographics, LNPCP location, morphology, resection modality, and histopathologic data. Multiple logistic regression analysis was used to identify those variables independently associated with rectal versus nonrectal location in the colon. RESULTS: Patients with LNPCPs referred for endoscopic resection between July 2008 and July 2021 were included. Rectal LNPCPs (n = 618) were larger (median size, 40 mm vs 30 mm; P < .001) and more likely to be granular (79% vs 50%, P < .001) with a nodular component (53% vs 17%, P < .001) compared with nonrectal LNPCPs (n = 2787). Rectal LNPCPs were more likely to have tubulovillous histopathology (72% vs 47%, P < .001) and contain cancer (15% vs 6%, P < .001). After adjusting for the other features independently associated with location, cancer was more common in the rectum compared with the colon (odds ratio, 1.77; 95% confidence interval, 1.25-2.53). CONCLUSIONS: This study suggests that compared with LNPCPs in the rest of the colon, rectal LNPCPs are more likely to be larger and contain more advanced pathology. These findings have implications for curative endoscopic resection techniques particularly where early cancer is present. (Clinical trial registration numbers: NCT01368289 and NCT02000141.).