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 15] 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 20] 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.

Oncological outcomes after piecemeal endoscopic mucosal resection of large non-pedunculated colorectal polyps with covert submucosal invasive cancer.

OBJECTIVE: Management of covert submucosal invasive cancer (SMIC) discovered after piecemeal endoscopic mucosal resection (pEMR) of large (>20 mm) non-pedunculated colorectal polyps is challenging. The residual cancer risk is largely unknown. We sought to evaluate this in a large tertiary referral cohort. DESIGN: Cases of covert SMIC following pEMR were identified and followed. Oncological outcomes after surgery were divided based on residual intramural cancer, lymph node metastases (LNM) or both. Risk factors for residual intramural cancer and LNM were analysed based on the original pEMR histological variables. Risk parameters were analysed with respect to low and high-risk variables for residual intramural cancer and LNM. RESULTS: Among 3372 cases of large non-pedunculated colorectal polyps, 143 cases of covert SMIC (4.2%) were identified. 109 underwent surgical resection. Histological analysis of pEMR histology was available in 98 of 109 (90%) cases. 62 cases (63%) had no residual malignancy. 36 cases had residual malignancy (residual intramural cancer n=24; LNM n=5; both n=7). All cases of residual intramural cancer could be identified by a R1 histological deep margin. Cases with poor differentiation (PD) and/or lymphovascular invasion (LVI) had a high risk of LNM (12/33), with a very low risk without these criteria (<1%; 0/65). Cases at low risk for LNM with R0 deep margin have a low risk of residual intramural cancer (<1%; 0/35). CONCLUSION: The majority of cases of large non-pedunculated colorectal polyps with covert SMIC following pEMR will have no residual malignancy. The risk of residual malignancy can be ascertained from three key variables: PD, LVI and R1 deep margin.

Outcomes of Deep Mural Injury After Endoscopic Resection: An International Cohort of 3717 Large Non-Pedunculated Colorectal Polyps.

BACKGROUND & AIMS: Although perforation is the most feared adverse event associated with endoscopic mucosal resection (EMR), limited data exists concerning its management. Therefore, we sought to evaluate the short- and long-term outcomes of intra-procedural deep mural injury (DMI) in an international multi-center observational cohort of large (≥20 mm) non-pedunculated colorectal polyps (LNPCPs). METHODS: Consecutive patients who underwent EMR for a LNPCP ≥20 mm were evaluated. Significant DMI (S-DMI) was defined as Sydney DMI Classification type III (muscularis propria injury, target sign) or type IV/V (perforation without or with contamination, respectively). The primary outcome was successful S-DMI defect closure. Secondary outcomes included technical success (removal of all visible polypoid tissue during index EMR), surgical referral and recurrence at first surveillance colonscopy (SC1). RESULTS: Between July 2008 to May 2020, 3717 LNPCPs underwent EMR. Median lesion size was 35mm (interquartile range (IQR) 25 to 45mm). Significant DMI was identified in 101 cases (2.7%), with successful defect closure in 98 (97.0%) using a median of 4 through-the-scope clips (TTSCs; IQR 3 to 6 TTSCs). Three (3.0%) patients underwent S-DMI-related urgent surgery. Technical success was achieved in 94 (93.1%) patients, with 46 (45.5%) admitted to hospital (median duration 1 day; IQR 1 to 2 days). Comparing LNPCPs with and without S-DMI, no differences in technical success (94 (93.1%) vs 3316 (91.7%); P = .62) or SC1 recurrence (12 (20.0%) vs 363 (13.6%); P = .15) were identified. CONCLUSIONS: Significant DMI is readily managed endoscopically and does not appear to affect technical success or recurrence.

Outcomes of Thermal Ablation of the Mucosal Defect Margin After Endoscopic Mucosal Resection: A Prospective, International, Multicenter Trial of 1000 Large Nonpedunculated Colorectal Polyps.

BACKGROUND & AIMS: Thermal ablation of the defect margin after endoscopic mucosal resection (EMR-T) for treating large (≥20 mm) nonpedunculated colorectal polyps (LNPCPs) has shown efficacy in a randomized trial, with a 4-fold reduction, in residual or recurrent adenoma (RRA) at first surveillance colonoscopy (SC1). The clinical effectiveness of this treatment, in the real world, remains unknown. METHODS: We sought to evaluate the effectiveness of EMR-T in an international multicenter prospective trial (NCT02957058). The primary endpoint was the frequency of RRA at SC1. Detailed demographic, procedural, and outcome data were recorded. Exclusion criteria were LNPCPs involving the ileo-caecal valve, the appendiceal orifice, and circumferential LNPCPs. RESULTS: During 51 months (May 2016-August 2020) 1049 LNPCPs in 1049 patients (median size, 35 mm; interquartile range, 25-45 mm; right colon location, 53.5%) were enrolled. Uniform completeness of EMR-T was achieved in 989 LNPCPs (95.4%). In this study, 755/803 (94.0%) eligible LNPCPs underwent SC1 (median time to SC1, 6 months; interquartile range, 5-7 months). For LNPCPs that underwent complete EMR-T, the frequency of RRA at SC1 was 1.4% (10/707). CONCLUSIONS: In clinical practice, EMR-T is a simple, inexpensive, and highly effective auxiliary technique that is likely to significantly reduce RRA at first surveillance. It should be universally used for the management of LNPCPs after EMR. https://clinicaltrials.gov; Clinical Trial Number, NCT02957058.

Cold snare piecemeal EMR of large sessile colonic polyps ≥20 mm (with video).

BACKGROUND AND AIMS: Conventional EMR using a hot snare is the standard of care for resection of large (≥20 mm) nonmalignant sessile colonic polyps. Serious adverse events are predominantly because of electrocautery. This could potentially be avoided by cold snare piecemeal EMR (CSP-EMR). This study aimed to evaluate the safety and efficacy of CSP-EMR of sessile colonic polyps sized ≥20 mm. METHODS: All cases of CSP-EMR at 5 Australian academic hospitals for sessile polyps ≥20 mm over a 2-year period, from January 2016 to December 2017, were identified retrospectively. Efficacy was defined as the absence of residual or recurrent polyp tissue during the first surveillance colonoscopy (SC1) and second surveillance colonoscopy (SC2). Clinically significant intraprocedural or delayed adverse events and surveillance colonoscopy findings were assessed by reviewing medical records. RESULTS: CSP-EMR was performed on 204 polyps sized ≥20 mm in 186 patients (men, 33.8%; median age, 68 years). SC1 for 164 polyps (80.4%) at a median interval of 150 days showed residual or recurrent polyp in 9 cases (5.5%; 95% confidence interval, 3%-11%). SC2 for 113 polyps (72.9%) at a median interval of 18 months showed late residual or recurrent polyp in 4 cases (3.5%; 95% confidence interval, .9%-8.5%) after a normal SC1. Intraprocedural bleeding was successfully treated in 4 patients (2.2%), whereas 7 patients (3.8%) experienced self-limited clinically significant post-EMR bleeding and 1 patient (.5%) required overnight observation for nonspecific abdominal pain that resolved spontaneously. None experienced other adverse events. CONCLUSIONS: CSP-EMR of sessile colonic polyps ≥20 mm is technically feasible, effective, and safe. The adverse event rate and polyp recurrence rate were low. Randomized or large prospective trials are required to confirm the noninferiority and improved safety of CSP-EMR compared with conventional EMR and to further determine the polyp morphologies that are best suited for CSP-EMR.

Impact of en bloc resection on long-term outcomes after endoscopic mucosal resection: a matched cohort study.

BACKGROUND AND AIMS: Residual or recurrent adenoma (RRA) is the major limitation of piecemeal EMR (p-EMR) for large colonic laterally spreading lesions (LSLs) ≥20 mm. En bloc EMR (e-EMR) has been shown to achieve low rates of RRA but specific procedural and long-term outcomes are unknown. Our aim was to compare long-term outcomes of size-matched LSLs stratified by whether they were resected e-EMR or p-EMR. METHODS: Data from a prospective tertiary referral multicenter cohort of large LSLs referred for EMR over a 10-year period were analyzed. Outcomes were compared between sized-matched LSLs (20-25 mm) resected by p-EMR or e-EMR. RESULTS: Five hundred seventy LSLs met the inclusion criteria of which 259 (45.4%) were resected by e-EMR. The risk of major deep mural injury (DMI) was significantly higher in the e-EMR group (3.5% vs 1.0%, P = .05), whereas rates of other intraprocedural adverse events did not differ significantly. Five of 9 (56%) LSLs, with endoscopic features of submucosal invasion (SMI), resected by e-EMR were saved from surgery. RRA at first surveillance was lower in the e-EMR group (2.0% vs 5.7%, P = .04), but this difference was negated at subsequent surveillance. Rates of surgical referral were not significantly different between the groups at either surveillance interval. CONCLUSION: When comparing e-EMR against p-EMR for lesions ≤25 mm in size of similar morphology in a large prospective multicenter cohort, e-EMR offered no additional advantage for predicted-benign LSLs. However, it was associated with an increased risk of major DMI. Thus, en bloc resection techniques should be reserved for lesions suspicious for invasive disease. (Clinical trial registration number: NCT01368289.).

Risk Stratification for Covert Invasive Cancer Among Patients Referred for Colonic Endoscopic Mucosal Resection: A Large Multicenter Cohort.

BACKGROUND & AIMS: Among patients with large colorectal sessile polyps or laterally spreading lesions, it is important to identify those at risk for submucosal invasive cancer (SMIC). Lesions with overt endoscopic evidence of SMIC are referred for surgery, although those without these features might still contain SMIC that is not visible on endoscopic inspection (covert SMIC). Lesions with a high covert SMIC risk might be better suited for endoscopic submucosal dissection than for endoscopic mucosal resection (EMR). We analyzed a group of patients with large colon lesions to identify factors associated with SMIC, and examined lesions without overt endoscopic high-risk signs to determine factors associated with covert SMIC. METHODS: We performed a prospective cohort study of consecutive patients referred for EMR of large sessile or flat colorectal polyps or laterally spreading lesions (≥20 mm) at academic hospitals in Australia from September 2008 through September 2016. We collected data on patient and lesion characteristics, outcomes of procedures, and histology findings. We excluded serrated lesions from the analysis of covert SMIC due to their distinct phenotype and biologic features. RESULTS: We analyzed 2277 lesions (mean size, 36.9 mm) from 2106 patients (mean age, 67.7 years; 53.2% male). SMIC was evident in 171 lesions (7.6%). Factors associated with SMIC included Kudo pit pattern V, a depressed component (0-IIc), rectosigmoid location, 0-Is or 0-IIa+Is Paris classification, non-granular surface morphology, and increasing size. After exclusion of lesions that were obviously SMIC or serrated, factors associated with covert SMIC were rectosigmoid location (odds ratio, 1.87; P = .01), combined Paris classification, surface morphology (odds ratios, 3.96-22.5), and increasing size (odds ratio, 1.16/10 mm; P = .012). CONCLUSIONS: In a prospective study of 2106 patients who underwent EMR for large sessile or flat colorectal polyps or laterally spreading lesions, we associated rectosigmoid location, combined Paris classification and surface morphology, and increasing size with increased risk for covert malignancy. Rectosigmoid 0-Is and 0-IIa+Is non-granular lesions have a high risk for malignancy, whereas proximally located 0-Is or 0-IIa granular lesions have a low risk. These findings can be used to inform decisions on which patients should undergo endoscopic submucosal dissection, EMR, or surgery. ClinicalTrials.gov, Number: NCT02000141.

The size, morphology, site, and access score predicts critical outcomes of endoscopic mucosal resection in the colon.

BACKGROUND: The SMSA (size, morphology, site, access) polyp scoring system is a method of stratifying the difficulty of polypectomy through assessment of four domains. The aim of this study was to evaluate the ability of SMSA to predict critical outcomes of endoscopic mucosal resection (EMR). METHODS: We retrospectively applied SMSA to a prospectively collected multicenter database of large colonic laterally spreading lesions (LSLs) ≥ 20 mm referred for EMR. Standard inject-and-resect EMR procedures were performed. The primary end points were correlation of SMSA level with technical success, adverse events, and endoscopic recurrence. RESULTS: 2675 lesions in 2675 patients (52.6 % male) underwent EMR. Failed single-session EMR occurred in 124 LSLs (4.6 %) and was predicted by the SMSA score (P < 0.001). Intraprocedural and clinically significant postendoscopic bleeding was significantly less common for SMSA 2 LSLs (odds ratio [OR] 0.36, P < 0.001 and OR 0.23, P < 0.01) and SMSA 3 LSLs (OR 0.41, P  < 0.001 and OR 0.60, P = 0.05) compared with SMSA 4 lesions. Similarly, endoscopic recurrence at first surveillance was less likely among SMSA 2 (OR 0.19, P < 0.001) and SMSA 3 (OR 0.33, P < 0.001) lesions compared with SMSA 4 lesions. This also extended to second surveillance among SMSA 4 LSLs. CONCLUSION: SMSA is a simple, readily applicable, clinical score that identifies a subgroup of patients who are at increased risk of failed EMR, adverse events, and adenoma recurrence at surveillance colonoscopy. This information may be useful for improving informed consent, planning endoscopy lists, and developing quality control measures for practitioners of EMR, with potential implications for EMR benchmarking and training.

Endoscopic mucosal resection for large serrated lesions in comparison with adenomas: a prospective multicentre study of 2000 lesions.

OBJECTIVE: Endoscopic mucosal resection (EMR) is effective for large laterally spreading flat and sessile lesions (LSLs). Sessile serrated adenomas/polyps (SSA/Ps) are linked to the relative failure of colonoscopy to prevent proximal colorectal cancer. We aimed to examine the technical success, adverse events and recurrence following EMR for large SSA/Ps in comparison with large conventional adenomas. DESIGN: Over 74 months till August 2014, prospective multicentre data of LSLs ≥20 mm were analysed. A standardised dye-based conventional EMR technique followed by scheduled surveillance colonoscopy was used. RESULTS: From a total of 2000 lesions, 323 SSA/Ps in 246 patients and 1527 adenomas in 1425 patients were included for analysis. Technical success for EMR was superior in SSA/Ps compared with adenomas (99.1% vs 94.5%, p<0.001). Significant bleeding and perforation were similar in both cohorts. The cumulative recurrence rates for adenomas after 6, 12, 18 and 24 months were 16.1%, 20.4%, 23.4% and 28.4%, respectively. For SSA/Ps, they were 6.3% at 6 months and 7.0% from 12 months onwards (p<0.001). Following multivariable adjustment, the HR of recurrence for adenomas versus SSA/Ps was 1.7 (95% CI 0.9 to 3.0, p=0.097). Subgroup analysis by lesion size revealed an eightfold increased risk of recurrence for 20-25 mm adenomas versus SSA/Ps, but no significantly different risk between lesion types in larger lesion groups. CONCLUSION: Recurrence after EMR of 20-25 mm LSLs is significantly less frequent in SSA/Ps compared with adenomatous lesions. SSA/Ps can be more effectively removed than adenomatous LSLs with equivalent safety. Ensuring complete initial resection is imperative for avoiding recurrence. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov NCT01368289.

Adenoma recurrence after piecemeal colonic EMR is predictable: the Sydney EMR recurrence tool.

BACKGROUND AND AIMS: EMR is the primary treatment of large laterally spreading lesions (LSLs) in the colon. Residual or recurrent adenoma (RRA) is a major limitation. We aimed to identify a robust method to stratify the risk of RRA. METHODS: Prospective multicenter data on consecutive LSLs ≥20 mm removed by piecemeal EMR from 8 Australian tertiary-care centers were included (September 2008 until May 2016). A logistic regression model for endoscopically determined recurrence (EDR) was created on a randomly selected half of the cohort to yield the Sydney EMR recurrence tool (SERT), a 4-point score to stratify the incidence of RRA based on characteristics of the index EMR. SERT was validated on the remainder of the cohort. RESULTS: Analysis was performed on 1178 lesions that underwent first surveillance colonoscopy (SC1) (median 4.9 months, interquartile range [IQR] 4.9-6.2). EDR was detected in 228 of 1178 (19.4%) patients. LSL size ≥40 mm (odds ratio [OR] 2.47; P < .001), bleeding during the procedure (OR 1.78; P = .024), and high-grade dysplasia (OR 1.72; P = .029) were identified as independent predictors of EDR and allocated scores of 2, 1, and 1, respectively to create SERT. Lesions with SERT scores of 0 (SERT = 0) had a negative predictive value of 91.3% for RRA at SC1, and SERT was shown to stratify RRA to specific follow-up intervals by using Kaplan Meier curves (log-rank P < .001). CONCLUSIONS: Guidelines recommend SC1 within 6 months of EMR. SERT accurately stratifies the incidence of RRA after EMR. SERT = 0 lesions could safely undergo first surveillance at 18 months, whereas lesions with SERT scores between 1 and 4 (SERT 1-4) require surveillance at 6 and 18 months. (Clinical trial registration number: NCT01368289.).

Clinical and endoscopic predictors of cytological dysplasia or cancer in a prospective multicentre study of large sessile serrated adenomas/polyps.

OBJECTIVE: The serrated neoplasia pathway accounts for up to 30% of all sporadic colorectal cancers (CRCs). Sessile serrated adenomas/polyps (SSA/Ps) with cytological dysplasia (SSA/P-D) are a high-risk serrated CRC precursor with little existing data. We aimed to describe the clinical and endoscopic predictors of SSA/P-D and high grade dysplasia (HGD) or cancer. DESIGN: Prospective multicentre data of SSA/Ps ≥20 mm referred for treatment by endoscopic mucosal resection (September 2008-July 2013) were analysed. Imaging and lesion assessment was standardised. Histological findings were correlated with clinical and endoscopic findings. RESULTS: 268 SSA/Ps were found in 207/1546 patients (13.4%). SSA/P-D comprised 32.4% of SSA/Ps ≥20 mm. Cancer occurred in 3.9%. On multivariable analysis, SSA/P-D was associated with increasing age (OR=1.69 per decade; 95% CI (1.19 to 2.40), p0.004) and increasing lesion size (OR=1.90 per 10 mm; 95% CI (1.30 to 2.78), p0.001), an 'adenomatous' pit pattern (Kudo III, IV or V) (OR=3.98; 95% CI (1.94 to 8.15), p<0.001) and any 0-Is component within a SSA/P (OR=3.10; 95% CI (1.19 to 8.12) p0.021). Conventional type dysplasia was more likely to exhibit an adenomatous pit pattern than serrated dysplasia. HGD or cancer was present in 7.2% and on multivariable analysis, was associated with increasing age (OR=2.0 per decade; 95% CI 1.13 to 3.56) p0.017) and any Paris 0-Is component (OR=10.2; 95% CI 3.18 to 32.4, p<0.001). CONCLUSIONS: Simple assessment tools allow endoscopists to predict SSA/P-D or HGD/cancer in SSA/Ps ≥20 mm. Correct prediction is limited by failure to recognise SSA/P-D which may mimic conventional adenoma. Understanding the concept of SSA/P-D and the pitfalls of SSA/P assessment may improve detection, recognition and resection and potentially reduce interval cancer. TRIAL REGISTRATION NUMBER: NCT01368289.

Cost Analysis of Endoscopic Mucosal Resection vs Surgery for Large Laterally Spreading Colorectal Lesions.

BACKGROUND & AIMS: Large laterally spreading lesions (LSL) in the colon and rectum can be safely and effectively removed by endoscopic mucosal resection (EMR). However, many patients still undergo surgery. Endoscopic treatment may be more cost effective. We compared the costs of endoscopic versus surgical management of large LSL. METHODS: We performed a prospective, observational, multicenter study of consecutive patients referred to 1 of 7 academic hospitals in Australia for the management of large LSL (≥ 20 mm) from January 2010 to December 2013. We collected data on numbers of patients undergoing EMR, actual endoscopic management costs (index colonoscopy, hospital stay, adverse events, and first surveillance colonoscopy), characteristics of patients and lesions, outcomes, and adverse events, and findings from follow-up examinations 14 days, 4-6 months, and 16-18 months after treatment. We compared data from patients who underwent EMR with those from a model in which all patients underwent surgery without any complications. Event-specific costs, based on Australian refined diagnosis-related group codes, were used to estimate average cost per patient. RESULTS: EMR was performed on 1489 lesions (mean size, 36 mm) in 1353 patients (mean age, 67 years; 52.1% male). Total costs involved in the endoscopic management of large LSL were US $6,316,593 and total inpatient hospitalization length of stay was 1180 days. The total cost predicted for the surgical management group was US $16,601,502, with a total inpatient hospitalization length of stay of 4986 days. Endoscopic management produced a potential total cost saving of US $10,284,909; the mean cost difference per patient was US $7602 (95% confidence interval, $8458-$9220; P < .001). Inpatient hospitalization length of stay was reduced by 2.81 nights per patient (95% confidence interval, 2.69-2.94; P < .001). CONCLUSIONS: In a large multicenter study, endoscopic management of large LSL by EMR was significantly more cost-effective than surgery. Endoscopic management by EMR at an appropriately experienced and resourced tertiary center should be considered the first line of therapy for most patients with this disorder. This approach is likely to deliver substantial overall health expenditure savings. ClinicalTrials.gov, Number: NCT01368289.

Prediction of Clinically Significant Bleeding Following Wide-Field Endoscopic Resection of Large Sessile and Laterally Spreading Colorectal Lesions: A Clinical Risk Score.

OBJECTIVES: Clinically significant bleeding (CSPEB) is the most frequent adverse event following wide-field endoscopic mucosal resection (WF-EMR) of large sessile and laterally spreading colorectal lesions (LSL). There is limited knowledge regarding accurate prediction of CSPEB. We aimed to derive a score to predict the risk of CSPEB. METHODS: Data on patient and lesion characteristics and outcomes from WF-EMRs of LSL ≥20 mm at 8 referral hospitals were analyzed. The cohort was divided at random into equal sized training and test groups. Independent predictors of CSPEB in the training cohort were identified by multiple logistic regression analysis and used to develop a risk score. The performance of this score was assessed in the independent test cohort. RESULTS: Over 80 months to June 2015, 2,128 patients with 2,424 LSL were referred for WF-EMR. Two thousand and twelve patients were eligible for analysis. There were 135 cases of CSPEB (6.7%). In the training cohort of 1,006 patients, the independent predictors of CSPEB were lesion size >30 mm (odds ratio (OR) 2.5), proximal colonic location (OR 2.3), presence of a major comorbidity (OR 1.5), and epinephrine in injection solution (OR 0.57). The derived risk score comprised lesion size >30 mm (2 points), proximal colon (2 points), presence of major comorbidity (1 point), and absence of epinephrine use (1 point). The probabilities of CSPEB for scores of 0, 1, 2, 3, 4, and ≥5 in the training cohort were 1.5, 2.0, 5.6, 7.8, 9.1, and 17.5% and were 0.9, 6.7, 4.9, 6.2, 9.0, and 15.7% in the test cohort. The probabilities of CSPEB in those with low (score 0-1), medium (score 2-4), and elevated (score 5-6) risk levels were 1.7, 7.1, and 17.5% in the training cohort and 3.4, 6.2, and 15.7% in the test cohort. CONCLUSIONS: Patients at elevated risk of CSPEB can be identified using four readily available variables. This knowledge may improve the management of those undergoing WF-EMR and assist in designing studies evaluating CSPEB.

Long-term adenoma recurrence following wide-field endoscopic mucosal resection (WF-EMR) for advanced colonic mucosal neoplasia is infrequent: results and risk factors in 1000 cases from the Australian Colonic EMR (ACE) study.

OBJECTIVE: Wide-field endoscopic mucosal resection (WF-EMR) is an alternative to surgery for treatment of advanced colonic mucosal neoplasia up to 120 mm in size, but has been criticised for its potentially high recurrence rates. We aimed to quantify recurrence at 4 months (early) and 16 months (late) following successful WF-EMR and identify its risk factors and clinical significance. DESIGN: Ongoing multicentre, prospective, intention-to-treat analysis of sessile or laterally spreading colonic lesions ≥20 mm in size referred for WF-EMR to seven academic endoscopy units. Surveillance colonoscopy (SC) was performed 4 months (SC1) and 16 months (SC2) after WF-EMR, with photographic documentation and biopsy of the scar. RESULTS: 1134 consecutive patients were enrolled when 1000 successful EMRs were achieved, of whom 799 have undergone SC1. 670 were normal. Early recurrent/residual adenoma was present in 128 (16.0%, 95% CI 13.6% to 18.7%). One case was unknown. The recurrent/residual adenoma was diminutive in 71.7% of cases. On multivariable analysis, risk factors were lesion size >40 mm, use of argon plasma coagulation and intraprocedural bleeding. Of 670 with normal SC1, 426 have undergone SC2, with late recurrence present in 17 cases (4.0%, 95% CI 2.4% to 6.2%). Overall, recurrent/residual adenoma was successfully treated endoscopically in 135 of 145 cases (93.1%, 95% CI 88.1% to 96.4%). If the initial EMR was deemed successful and did not contain submucosal invasion requiring surgery, 98.1% (95% CI 96.6% to 99.0%) were adenoma-free and had avoided surgery at 16 months following EMR. CONCLUSIONS: Following colonic WF-EMR, early recurrent/residual adenoma occurs in 16%, and is usually unifocal and diminutive. Risk factors were identified. Late recurrence occurs in 4%. Overall, recurrence was managed endoscopically in 93% of cases. Recurrence is not a significant clinical problem following WF-EMR, as with strict colonoscopic surveillance, it can be managed endoscopically with high success rates. TRIAL REGISTRATION NUMBER: NCT01368289.

A management algorithm based on delayed bleeding after wide-field endoscopic mucosal resection of large colonic lesions.

BACKGROUND & AIMS: Bleeding is the main complication of wide-field endoscopic mucosal resection (WF-EMR) for large colonic lesions. Few studies have examined bleeding outcomes after WF-EMR, and there are no evidence-based guidelines for management of bleeding in this group. We analyzed outcomes of patients with clinically significant post-EMR bleeding (CSPEB) and present a management algorithm based on our findings. METHODS: In a prospective study, we collected data from WF-EMR of sessile colorectal polyps 20 mm or larger from 1039 patients who participated in the Australian Colonic Endoscopic resection multicenter study from July 2008 through May 2012. Data included patient and lesion characteristics and procedural, clinical, and histologic outcomes. Patients participated in a structured telephone interview 14 days after the procedure; independent predictors of a moderate or severe outcome by American Society of Gastrointestinal Endoscopists criteria, or any intervention for hemostasis, were identified. RESULTS: Sixty-two patients had CSPEB (6.0%); 34 were managed conservatively (55%) and 27 underwent colonoscopy (44%). One patient had primary embolization. Endoscopic therapy was applied in 21 cases; 14 had active bleeding. Two of the conservatively managed cases underwent colonoscopy for rebleeding after discharge. On multivariable analysis, moderate or severe bleeding events were associated with hemodynamic instability (odds ratio, 12.3; P = .046) and low level of hemoglobin at presentation (odds ratio, 0.50 per 1.0 g/dL; P = .005). Intervention for hemostasis was associated with hourly or more frequent hematochezia (odds ratio, 36.7; P = .001), American Society of Anesthesiologists grade 2 or higher (odds ratio, 20.1; P < .001), and transfusion (odds ratio, 18.7; P = .003). CONCLUSIONS: Based on a multicenter prospective study, CSPEB resolves spontaneously in 55% of patients. We developed a risk factor-based algorithm that might assist physicians in the management of bleeding. Patients responding to initial resuscitation can be observed, with a lower threshold for intervention in those with the identified risk factors.

Risk factors for intraprocedural and clinically significant delayed bleeding after wide-field endoscopic mucosal resection of large colonic lesions.

BACKGROUND & AIMS: Wide-field endoscopic mucosal resection (WF-EMR) of large sessile colonic polyps is a safe and cost-effective outpatient treatment. Bleeding is the main complication. Few studies have examined risk factors for bleeding during the procedure (intraprocedural bleeding [IPB]) or after it (clinically significant post-endoscopic bleeding [CSPEB]). We investigated factors associated with IPB and CSPEB in a large prospective study. METHODS: We analyzed data from WF-EMRs of sessile colorectal polyps ≥ 20 mm in size (mean size, 35.5 mm), which were performed on 1172 patients (mean age, 67.8 years) from June 2008-March 2013 at 7 tertiary hospitals as part of the Australian Colonic Endoscopic Resection Study. Data were collected on characteristics of patients and lesions, along with outcomes of procedures and clinical and histologic analyses. Independent predictors of IPB and CSPEB were identified by multiple logistic regression analysis. RESULTS: Of the patients studied, 133 (11.3%) had IPB. Independent predictors included increasing lesion size (odds ratio, 1.24/10 mm; P < .001), Paris endoscopic classification of 0-IIa + Is (odds ratio, 2.12; P = .004), tubulovillous or villous histology (odds ratio, 1.84; P = .007), and study institutions that performed the procedure on fewer than 75 patients (odds ratio, 3.78; P < .001). All IPB was successfully controlled endoscopically. IPB prolonged procedures and was associated with early recurrence (relative risk, 1.68; P = .011). Seventy-three patients (6.2%) had CSPEB. On multivariable analysis, CSPEB was associated with proximal colon location (odds ratio, 3.72; P < .001), use of an electrosurgical current not controlled by a microprocessor (odds ratio, 2.03; P = .038), and IPB (odds ratio, 2.16; P = .016). Lesion size and comorbidities did not predict CSPEB. CONCLUSIONS: In a prospective study of patients undergoing WF-EMR of large sessile colonic polyps, IPB is associated with larger lesions, lesion histology, and Paris endoscopic classification of type 0-IIa + Is. IPB prolongs the duration of the procedure, is a marker for recurrence, and is associated with CSPEB. CSPEB occurs most frequently in the proximal colon and less when current is controlled by a microprocessor.

Actual endoscopic versus predicted surgical mortality for treatment of advanced mucosal neoplasia of the colon.

BACKGROUND: EMR of advanced mucosal neoplasia (AMN) (ie, sessile or laterally spreading lesions of ≥20 mm) of the colon has become an increasingly popular alternative to surgical resection. However, data regarding safety and mortality of EMR in comparison to surgery are limited. OBJECTIVE: To compare actual endoscopic with predicted surgical mortality. DESIGN: Prospective, observational, multicenter cohort study. SETTING: Academic, high-volume, tertiary-care referral center. PATIENTS: Consecutive patients referred for EMR. INTERVENTION EMR MAIN OUTCOME MEASUREMENTS: To predict hypothetical surgical mortality, the Association of Coloproctology of Great Britain and Ireland score, composed of physiological and surgical components, was calculated for each patient. Predicted surgical mortality was then compared with actual outcomes of EMR. The results were validated by an unselected subcohort by using the Colorectal Physiologic and Operative Severity Score for Enumeration of Mortality and Morbidity. RESULTS: Among 1050 patients with AMN treated by EMR, including patients with a predicted mortality rate of greater than 5% (13.8% of cohort), no deaths occurred within 30 days after the procedure. The predicted surgical mortality rate was 3.3% with the Association of Coloproctology of Great Britain and Ireland score (P < .0001). This suggests a significant advantage of EMR over surgery. The results were validated by using the Colorectal Physiologic and Operative Severity Score for Enumeration of Mortality and Morbidity in 390 patients predicting a surgical mortality rate of 3.2% (P = .0003). LIMITATIONS: Nonrandomized study. CONCLUSION: In this large multicenter study of EMR for colonic AMN, the predicted surgical mortality rate was significantly higher than the actual endoscopic mortality rate. Given that endoscopic therapy is less morbid and less expensive than surgery and can be performed as an outpatient treatment, it should be considered as the first line of treatment for most patients with these lesions.

Endoscopic mucosal resection outcomes and prediction of submucosal cancer from advanced colonic mucosal neoplasia.

BACKGROUND & AIMS: Large sessile colonic polyps usually are managed surgically, with significant morbidity and potential mortality. There have been few prospective, intention-to-treat, multicenter studies of endoscopic mucosal resection (EMR). We investigated whether endoscopic criteria can predict invasive disease and direct the optimal treatment strategy. METHODS: The Australian Colonic Endoscopic (ACE) resection study group conducted a prospective, multicenter, observational study of all patients referred for EMR of sessile colorectal polyps that were 20 mm or greater in size (n=479, mean age, 68.5 y; mean lesion size, 35.6 mm). We analyzed data on lesion characteristics and procedural, clinical, and histologic outcomes. Multiple logistic regression analysis identified independent predictors of EMR efficacy and recurrence of adenoma, based on findings from follow-up colonoscopy examinations. RESULTS: Risk factors for submucosal invasion were as follows: Paris classification 0-IIa+c morphology, nongranular surface, and Kudo pit pattern type V. The most commonly observed lesion (0-IIa granular) had a low rate of submucosal invasion (1.4%). EMR was effective at completely removing the polyp in a single session in 89.2% of patients; risk factors for lack of efficacy included a prior attempt at EMR (odds ratio [OR], 3.8; 95% confidence interval, 1.77-7.94; P=.001) and ileocecal valve involvement (OR, 3.4; 95% confidence interval, 1.20-9.52; P=.021). Independent predictors of recurrence after effective EMR were lesion size greater than 40 mm (OR, 4.37; 95% confidence interval, 2.43-7.88; P<.001) and use of argon plasma coagulation (OR, 3.51; 95% confidence interval, 1.69-7.27; P=.0017). There were no deaths from EMR; 83.7% of patients avoided surgery. CONCLUSIONS: Large sessile colonic polyps can be managed safely and effectively by endoscopy. Endoscopic assessment identifies lesions at increased risk of containing submucosal cancer. The first EMR is an important determinant of patient outcome-a previous attempt is a significant risk factor for lack of efficacy.