Large Colonic Polyps Research Articles

Efficacy of Prophylactic Hemoclips in Prevention of Delayed Post-Polypectomy Bleeding in Patients With Large Colonic Polyps

The efficacy of prophylactic placement of hemoclips to prevent delayed bleeding after removal of large colonic polyps has not been established. We conducted a randomized equivalence study to determine whether prophylactic placement of hemoclips affects incidence of delayed post-polypectomy bleeding (PPB). During elective colonoscopy performed at 4 Veterans Affairs Medical Centers, 1098 patients who had polyps ≥1 cm removed were randomly assigned to groups that received prophylactic hemoclips (n= 547) or no hemoclips (n= 551), from September 2011 through September 2018. Data on PPB (rectal bleeding resulting in hemoglobin decreases ≥2 g/dL, hemodynamic instability, colonoscopy, angiography, or surgery) within 30 days of colonoscopy (called delayed PPB) were collected during telephone interviews or hospital visits 7 and 30 days after colonoscopy. The primary outcome was theincidence of important post-polypectomy bleeding. Twelve patients in the hemoclip group (2.3%) and 15 patients in the no hemoclip group (2.9%) had important delayed PPB. There were no deaths, and no patients in either group required angiography or surgery. In intention-to-treat analysis, two 1-sided test's lower and upper confidence interval limits were -2.07 and 1.01, indicating that the data approached but did not meet equivalence criteria. On multiple logistic regression analysis, significant predictors of PPB included use of warfarin with bridging, thienopyridines, polyp size, and polyp location, but hemoclip placement did not associate with important delayed PPB. In a randomized trial, we found that prophylactic placement of hemoclips after removal of large colon polyps does not affect the proportion of important delayed PPB events, compared with no hemoclip placement. These findings call into question the widespread, expensive practice of routinely placing prophylactic hemoclips after polypectomy. ClinicalTrials.gov ID: NCT01647581.

Clip Closure Prevents Bleeding After Endoscopic Resection of Large Colon Polyps in a Randomized Trial

Bleeding is the most common severe complication after endoscopic mucosal resection of large colon polyps and is associated with significant morbidity and cost. We examined whether prophylactic closure of the mucosal defect with hemoclips after polyp resection reduces the risk of bleeding. We performed a multicenter, randomized trial of patients with a large nonpedunculated colon polyp (≥20 mm) at 18 medical centers in North America and Spain from April 2013 through October 2017. Patients were randomly assigned to groups that underwent endoscopic closure with a clip (clip group) or no closure (control group) and followed. The primary outcome, postprocedure bleeding, was defined as a severe bleeding event that required hospitalization, a blood transfusion, colonoscopy, surgery, or another invasive intervention within 30 days after completion of the colonoscopy. Subgroup analyses included postprocedure bleeding with polyp location, polyp size, or use of periprocedural antithrombotic medications. We also examined the risk of any serious adverse event. A total of 919 patients were randomly assigned to groups and completed follow-up. Postprocedure bleeding occurred in 3.5% of patients in the clip group and 7.1% in the control group (absolute risk difference [ARD] 3.6%; 95% confidence interval [CI] 0.7%-6.5%). Among 615 patients (66.9%) with a proximal large polyp, the risk of bleeding in the clip group was 3.3% and in the control group was 9.6% (ARD 6.3%; 95% CI 2.5%-10.1%); among patients with a distal large polyp, the risks were 4.0% in the clip group and 1.4% in the control group (ARD -2.6%; 95% CI -6.3% to -1.1%). The effect of clip closure was independent of antithrombotic medications or polyp size. Serious adverse events occurred in 4.8% of patients in the clip group and 9.5% of patients in the control group (ARD 4.6%; 95% CI 1.3%-8.0%). In a randomized trial, we found that endoscopic clip closure of the mucosal defect following resection of large colon polyps reduces risk of postprocedure bleeding. The protective effect appeared to be restricted to large polyps located in the proximal colon. ClinicalTrials.gov no: NCT01936948.

Ileocaecal Crohn’s disease and familial adenomatous polyposis in one patient – a case report

Crohn’s disease (CD) and Familial adenomatous polyposis (FAP) are two different diseases which both affect gastrointestinal tract. FAP is an autosomal dominant inherited disease, however the etiology of CD is still unknown but is supposed to be multifactorial (genetics, environment, immune state, microbiom). The therapy of these two diseases differs as well. The ultimate solution for FAP is surgery (colectomy or proctocolectomy). On the other hand, the therapy of CD can be either conservative or surgical. Generally, in cases of bowel resections the alternatives of gastrointestinal tract restoration have to be considered in advance. Furthermore, this decision is even more demanding in patients diagnosed with both diseases (CD and FAP). We present a case of a young female with FAP who was recently diagnosed with active CD in the ileocaecal region. Due to large multiple colon polyps and stenotic terminal ileum she was indicated for surgery (colectomy with terminal ileostomy and terminal ileum resection). Subsequently, the ileorectal anastomosis was constructed in this case. In further text, we also discuss other types of possible bowel restoration solutions (ileal pouch-anal anastomosis and abdominoperineal resection with terminal ileostomy) in such a patient.

Effect of time of day and daily endoscopic workload on outcomes of endoscopic mucosal resection for large sessile colon polyps.

Endoscopic mucosal resection of large non-pedunculated colon polyps is challenging. To determine if the time of day or daily endoscopic workload play a role in outcomes of endoscopic mucosal resection for large non-pedunculated colon polyps greater than 20 mm. This is a retrospective study of patients who underwent endoscopic mucosal resection of large non-pedunculated colon polyps. The time of day and endoscopic workload were compared across the following outcomes: the rate of complete resection of the polyp, the rate of referral for surgery, and the rate of residual neoplasia on follow-up. One hundred and three endoscopic mucosal resection procedures were performed. There were no differences in the rates of complete resection (80.8% vs. 70.0%; P = 0.25), the need for surgery (27.4% vs. 33.3%; P = 0.55), and rate of residual neoplasia (24.5% vs. 50.0%; P = 0.07) when comparing the time of day. Colon polyps greater than 40 mm were less likely to be completely resected versus polyps sized 20-39 mm (56.8% vs. 91.9%; P < 0.001). In cases with no residual neoplasia on follow-up, the mean duration for the index procedure was 45.6 minutes versus 60.7 minutes when there was residual neoplasia (P < 0.01). The time of day and endoscopic workload does not affect outcomes for endoscopic mucosal resection of large non-pedunculated colon polyps, but the size of large non-pedunculated colon polyps and resection times do.

The Incidence of and Risk Factors for Local Recurrence With Malignancy After Endoscopic Resection of Large Colon Polyps With High Grade Dysplasia

Introduction: In western countries, most benign large colonic polyps (LCP) are removed by piecemeal endoscopic resection. This technique has gained widespread acceptance as most recurrences are believed to be local, benign and amenable to further endoscopic management. Malignancy at the resection site of benign polyps with high grade dysplasia (HGD), has been described in Asian literature, and is of concern. We evaluated the incidence of local invasive colorectal carcinoma (CRC) at prior polypectomy site of LCP with HGD, and the associated risk factors. Methods: This retrospective study identified consecutive patients undergoing complete endoscopic resection of LCP >= 20 mm with HGD, at a single large Western center between January 2000 and December 2016. Demographic, clinical, endoscopic and pathologic data were abstracted from the patients’ index procedure. Follow up data to identify recurrent disease were collected from all subsequent endoscopic and surgical procedures, radiologic imaging, and pathology. Exclusion criteria included a grossly incomplete initial resection, polyposis syndromes and personal history of colon cancer. Results: A total of 254 LCP with HGD were resected in 229 patients. Median polyp size was 29.2 mm (range: 20 -100 mm). 138 lesions were resected in piecemeal fashion and 116 en-bloc. Cancer was diagnosed at the site of polypectomy on follow-up in six cases. Of these cases, three cases were diagnosed at early stage (stage I or II), and three cases were diagnosed at advanced stage (stage III or IV) (Table 1). Median time to cancer diagnosis was 28.5 months. Distant metastatic disease was found at time of the diagnosis in two cases. Based on time-to-event analysis, the estimated incidence of cancer related to the index polyp was 1.3% at 1 year and 4.5% at 5 years (Figure 1). Table 2 presents the analysis of risk factors for the local recurrence with malignancy. Although not statistically significant, all malignant cases occurred after piecemeal resection and none after en-bloc resection (HR, 11.4; 95% CI, 0.48-273.0, p = 0.13)113_A Figure 1. The cumulative incidence of invasive malignancy by resection method and size of lesionConclusion: Malignancy after endoscopic resection of LCP with HGD is uncommon but if diagnosis is delayed it can be lethal. Close endoscopic surveillance is crucial and when possible en-bloc ESD resection, which is associated with lower recurrence rates, should be considered for LCP with HGD113_B Figure 2. Characteristics of Local Recurrence with Invasive Malignancy113_C Figure 3. Analysis of Factors for Local Recurrence with Malignancy: Unadjusted Marginal Cox Regression Analysis

Standardizing the Removal of Large Colon Polyps: An Evidence-Based Approach

Standardizing the Removal of Large Colon Polyps: An Evidence-Based Approach

An unusual diverticulum adjacent to two large colonic polyps; a case report

BackgroundAdenocarcinomas can arise in a variety of circumstances in which intestinal segments have been used for urinary diversions. Whereas ureterosigmoidostomy is the oldest and simplest form of continent urinary diversion it also seems to be the most dangerous in this regard. Herein we present a case of colonic neoplasia complicating a non-functioning ureterosigmoidostomy after 55 years; the longest latent period documented to date.Case presentationA 56-year-old lady born with congenital bladder exystrophy and who had a functional ileal conduit presented to us with a 6 month history of change in bowel habit and rectal bleeding. Prior to this she had had multiple abdominal surgeries as a child and had suffered from lifelong recurrent urinary tract infections.Colonoscopy revealed the presence of two large sessile polyps in close proximity to a diverticulum-like structure that after surgical resection turned out to be a non-functioning ureterosigmoidostomy from when she was an infant.ConclusionsOur case highlights the importance of enrolling patients with ureterosigmoidostomies into long-term colonoscopic surveillance programmes. This is also true for those patients who undergo revisional surgery but have preserved ureteric stumps. Endoscopists should be aware of the varied endoscopic appearances of the anastamosis in order to be able to recognise these structures when present.

Utility and performance characteristics of a novel submucosal injection agent (EleviewTM) for endoscopic mucosal resection and endoscopic submucosal dissection.

Submucosal injection of a lifting agent is a critical step in endoscopic mucosal resection (EMR), and endoscopic submucosal dissection (ESD). Literature suggests superiority of other viscous solutions over normal saline (NS), but research to determine the ideal submucosal injection is still ongoing. In this prospective cohort study, we evaluated the utility and performance characteristics of a novel submucosal injection agent (EleviewTM) for EMR and ESD. Twelve consecutive patients referred for EMR/ESD to a tertiary referral center with experienced large polyp expert were prospectively enrolled. Ten patients with large colon polyps (mean age 66.3 years), and one patient each with esophageal and gastric lesions were included. EleviewTM was injected as submucosal lifting agent, and EMR/ESD performed. Main outcome measurements included the duration of submucosal elevation, volume and number of injections required to maintain cushion, and complications. Single injection of 3-5 cc of EleviewTM outlasted the duration of EMR. However, mean duration of cushion achieved during longer procedures (ESD) was 12.5 min, requiring several additional injections. R0 resection was achieved in 10/12 patients. One patient had minor bleeding which was managed intra-operatively. EleviewTM was successful in achieving long duration of submucosal elevation, allowing safe and efficient performance of EMR as a single injection, but needed repeated injections during longer ESD procedures. Prospective controlled trials are required to compare its performance to other available viscous submucosal solutions.

Mo1151 EFFECT OF ENDOSCOPIST FATIGUE IN RELATION TO ENDOSCOPIC MUCOSAL RESECTION OF LARGE COLON POLYPS

Endoscopic mucosal resection (EMR) of large colon polyps is technically challenging and therefore often performed by endoscopists with significant experience in this procedure. It is not known if endoscopist fatigue influences the success of colon EMR for large colon polyps. The primary objective of our study is to assess whether procedural success of colon EMR is affected by endoscopist fatigue or time of day when colon EMR is performed. We conducted a retrospective review of all colon EMR procedures performed by four therapeutic endoscopists at two academic tertiary care hospitals between 1/1/2015 – 12/31/2016. Patients included for this review had colon polyps > 20 mm that were removed with injection-lift EMR technique. Technical success was defined as endoscopist assessment of complete resection of the polyp. All patients for whom follow-up information was available were assessed for residual neoplasia on follow-up colonoscopy. We assessed whether endoscopist fatigue as measured by: afternoon versus morning, number of endoscopic procedures performed before the procedure under consideration, including adjustment for procedure complexity and the total procedure related RVUs had an impact on the technical success of the procedure or the rate of residual neoplasia. In order to examine these fatigue measures we stratified the cases under review into quartiles. Quartile 1 represents the colon EMR cases with fewest preceding cases, while quartile 4 represents colon EMR cases with the largest number of preceding cases. A total of 154 patients underwent colonoscopy to resect 170 large colon polyps by EMR technique. Overall, 87.7% of the lesions were removed successfully. 21 lesions could not be removed endoscopically. Follow-up information was available for 68.3% of patients. 28 patients underwent surgery (14 for invasive carcinoma, 3 for high grade dysplasia, 11 for unresectable lesions). Of 75 patients who underwent successful colon EMR and had follow-up colonoscopy, 80% had no evidence of residual neoplasia. When assessing endoscopist fatigue by total number of procedures, number of procedures adjusted for complexity and total procedure-related RVUs prior to performing colon EMR, no effect was found in relation to technical success or rates of residual neoplasia on follow-up. There appeared to be a trend towards lower rate of technical success and a higher rate of residual neoplasia for colon EMR procedures performed in the afternoon versus the morning, however this difference was not statistically significant. We conducted similar analysis for each endoscopist individually with the same findings. Endoscopist fatigue did not have a significant effect on the technical success of colon EMR, nor did it adversely impact the rate of residual neoplasia on follow-up colonoscopy.Tabled 1Association between endoscopist fatigue and colon EMR outcome measuresFatigue measureTechnical successResidual neoplasia rateStart timeMorning exam89.5% (referant)20.4% (referent)Afternoon exam83.0% (p=0.25)34.8% (p=0.18)Raw fatigue scoreQuartile 192.7% (referent)25.0% (referent)Quartile 284.4% (p = 0.27)32.1% (p=0.62)Quartile 381.6% (p= 0.14)30.8% (p=0.73)Quartile 490.2% (p=0.69)15.8 % (p=0.50)Consensus fatigue scoreQuartile 192.7% (referent)25.0% (referent)Quartile 281.6% (p=0.15)26.3% (p=0.93)Quartile 382.5% (p =0.18)30.0% (p=0.74)Quartile 490.9% (p=0.77)13.6% (p=0.38)RVU fatigue scoreQuartile 192.7% (referent)25.0% (referent)Quartile 280.5% (p=0.12)26.3% (p=0.93)Quartile 380.5% (p=0.12)36.8% (p=0.43)Quartile 495.0% (p=0.67)15.8% (p=0.48) Open table in a new tab

Risk stratification of colorectal polyps for predicting residual or recurring adenoma using the Size/Morphology/Site/Access score.

Endoscopic mucosal resection is an effective and safe procedure to manage large non-pedunculated colonic polyps for which residual/recurrent adenoma is the main drawback. Size/Morphology/Site/Access score determines polypectomy difficulty. We aimed to describe residual/recurrent adenoma rate according to Size/Morphology/Site/Access and to select the ize/Morphology/Site/Access cut-off to predict low residual/recurrent adenoma. This was a retrospective cohort study of endoscopic mucosal resection for large non-pedunculated colonic polyps performed in a tertiary centre. Three hundred and sixteen procedures were included. The mean size of lesions was 34.5 ± 17.1 mm, 59.5% were sessile, 60.4% were in the right colon and in 17.7% (n = 56) the access was difficult. Of the lesions, 83.6% were Size/Morphology/Site/Access 3-4. Residual/recurrent adenoma at first and second follow-up was significantly lower in Size/Morphology/Site/Access 2 (1.9% and 0.0%, respectively) when compared to Size/Morphology/Site/Access 3 (18.2%, p = 0.004 and 6.7%, p = 0.049) and Size/Morphology/Site/Access 4 (30.8%, p < 0.001 and 22.7%, p = 0.030). The negative predictive value of Size/Morphology/Site/Access 2 for residual/recurrent adenoma at second follow-up was 86.1%. On multivariate analyses, Size/Morphology/Site/Access 3-4 predicted residual/recurrent adenoma at first (odds ratio 11.96, 95% confidence interval 1.57-91.13) and second follow-up (odds ratio 2.47, 95% confidence interval 1.51-4.22) and had higher cumulative incidence of residual/recurrent adenoma compared to Size/Morphology/Site/Access 2 (p ≤ 0.003). Use of the Size/Morphology/Site/Access score allows cases to be identified with a low risk of residual/recurrent adenoma.

Recent advances in the management of large and complex colonic polyps.

The endoscopic management of large colonic polyps is a rapidly changing field. Rapid evolution in endoscopic techniques and skills has resulted in diminishing the role of surgery in the management of larger and complex polyps. This is resulting in organ preservation for many who otherwise would have undergone surgery. However, it also poses new challenges. This article reviews these new advances and the developments which are overcoming these difficulties.

Characteristics of Patients with Colonic Polyps Requiring Segmental Resection.

Background It is unclear if the availability of new techniques for removal of large colonic polyps has affected the use of segmental colon resection. We sought to evaluate the characteristics of polyps undergoing surgical resection, including involvement of therapeutic gastroenterologists (TG). Methods 484 patients had a colonic resection; 165 (34%) were identified from the pathology database with polyp, adenoma, or mass in the clinical history field; these charts were reviewed. Results 128 patients (mean age 68 yrs, 72% male) were included. The mean polyp size was 2.9 cm (0.4 cm–12.0 cm). Adenocarcinoma was diagnosed in 50 (39.1%). 97 (75.8%) patients had a polyp that was felt to be unresectable by EMR, and 31 (24.2%) underwent successful EMR followed by surgery for adenocarcinoma (n = 29). The indication for surgery in those with unresectable polyps was variable and was not clearly documented in 51 (52.6%); only 17 of these patients (17.5%) had a TG involved. Conclusion A high proportion of polyps managed by segmental resection did not contain adenocarcinoma. This data suggests that even in a tertiary care center where advanced endoscopic techniques are easily available, they are not always utilized. Educational endeavors to ensure that ideal pathways of intervention are utilized require implementation.

Underwater endoscopic mucosal resection: an alternative treatment for large colorectal polyp removal.

Large sessile/flat colonic polyps are traditionally removed by lift polypectomy. Underwater endoscopic mucosal resection (UEMR) is a novel technique where air is suctioned out and replaced by water to decompress the colon so that the flat lesions assumes a more polypoid shape facilitating its removal with the standard snare resection. We report the feasibility and safety in our series of patients utilizing this technique. A retrospective, observational study of all patients who underwent removal of large colonic polyps (>10 mm) over a period of 3 years (January 2012 to January 2015) at a tertiary care center by UEMR were included in the study. A total of 102 polyps were removed in 93 adult patients using UEMR. The mean age of patients was 64.7±9.7 years. The average number of polyps per patient was 1.84±1.3 with a range of 1-7. The range of the polyp size was 10 to 60 mm. The mean size of the polyp was 20.4±9.4 mm, median size 26.9±9.4 mm. Ninety-two (90.2%) were removed in piecemeal fashion and ten (9.8%) were removed en bloc. Delayed bleeding occurred in seven (9.7%) patients. In this largest series on UEMR, we report the feasibility and safety of this procedure. Future randomized trials comparing this technique versus standard lift polypectomy technique will further elucidate the benefit of one over other.

1004 A Prospective, Randomized Trial of Prophylactic Hemoclipping for Preventing Delayed Post-Polypectomy Bleeding in Patients With Large Colonic Polyps: An Interim Analysis

1004 A Prospective, Randomized Trial of Prophylactic Hemoclipping for Preventing Delayed Post-Polypectomy Bleeding in Patients With Large Colonic Polyps: An Interim Analysis

Su1611 Outcome of a Protocol Driven Endoscopic Resection of Patients With Large Colon Polyps (>20 MM) Results in Low Complications and Recurrence

Su1611 Outcome of a Protocol Driven Endoscopic Resection of Patients With Large Colon Polyps (>20 MM) Results in Low Complications and Recurrence

Tu1027 Better Management of Patients With Large Colon Polyps Requires Improvement in the Knowledge Gaps Among Referring Endoscopists

Tu1027 Better Management of Patients With Large Colon Polyps Requires Improvement in the Knowledge Gaps Among Referring Endoscopists

Mo1806 - Outcome of Endoscopic Resection of Large Colonic Polyps by Endoscopic Mucosal Resection or Endoscopic Submucosal Dissection in Patients with Inflammatory Bowel Disease

Mo1806 - Outcome of Endoscopic Resection of Large Colonic Polyps by Endoscopic Mucosal Resection or Endoscopic Submucosal Dissection in Patients with Inflammatory Bowel Disease

Snare Entrapment and Bleeding in Large Colonic Polyp: A Case Report

Snare entrapment is an uncommon but serious complication of polypectomy and frequently requiring surgery. We report a case of snare entrapment in large bleeding sigmoid colon removed with forcep and treated with Hemospray. Non-surgical management of snare entrapment during polypectomy included the

Endoscopic resection using the Clutch Cutter and a detachable snare for large pedunculated colonic polyps.

Background and study aims Endoscopic snare polypectomy with prophylactic detachable snare of large pedunculated colonic polyps (PCPs) is technically demanding. To facilitate removal of such polyps, we developed endoscopic resection using the Clutch Cutter and a detachable snare (ERCCDS). This study aimed to evaluate the efficacy and safety of the procedure. Patients and methods From April 2010 to July 2015, 14 consecutive patients who had PCPs with head > 10 mm, stalk width > 5 mm, and stalk length > 10 mm were enrolled in this single-center prospective uncontrolled study. They were treated using ERCCDS by a single endoscopist. The efficacy and safety were assessed using a database prospectively formatted from the medical records. Results The Clutch Cutter was able to cut the distal side of the stalk an adequate distance from the detachable snare under good visual control. R0 resections were obtained in all lesions. There were no immediate or delayed complications. Conclusions ERCCDS appears to be a safe, easy, and technically efficient method for large PCPs, although larger studies are needed to compare ERCCDS and standard resection.

Risk Factors Associated with Incomplete Endoscopic Mucosal Resection of Colonic Polyps

Introduction: Risk factors for incomplete endoscopic mucosal resection (EMR) of large colonic polyps are uncertain. We aimed to characterize the rates and risk factors of incomplete resections (IR) at a single US center. We hypothesize that polyp size > 40mm predicts IR and resections initiated by endoscopists specializing in colonic EMR protect against IR. Methods: Using an electronic endoscopic database, we identified patients who underwent EMR with at least one follow up colonoscopy from 2006-2015 at our institution. Patients with IBD were excluded. The primary outcome (IR) was defined as cases which the provider noted residual polyp at the end of the first resection attempt. Polyp characteristics and the endoscopist first performing EMR (specialist (SE) vs. non-specialist endoscopist) were noted. Univariate and multivariate analysis was used to identify factors associated with IR. Clinical outcomes were recorded. Results: 258 patients with 289 polyps underwent EMR with at least one follow up colonoscopy. 39/258 (15%) had IR. Age, gender, polyp location, and follow up were similar between complete resections (CR) and IR (Table 1). SE as the sole EMR provider achieved CR in fewer colonoscopies than non-SE± subsequent SE referral (mean 2.4 vs. 3, p< 0.0001). On univariate and multivariate logistic regressions, polyp > 40 mm (odds ratio [OR] = 2.3; 95% confidence interval [CI] = 1.1-14.9), piecemeal removal (OR = 7.5, CI 1.8-31.9), and difficulty lifting the polyp (OR = 3.1, CI 1.1-8.9) were associated with IR. Resections performed by SE alone were protective against IR (OR 0.31, CI 0.15-0.65). Based on our regression model, the probability of IR in piecemeal resections of polyps>40 mm with and without difficulty lifting (and started by a non-SE) is 88% and 56%,respectively. When SE are the sole EMR provider, the probability of IR drops to 41% and 11%, respectively, (Figure 1). Of the IR patients, 12 (28%) were referred for surgery, 2 of which were for adenocarcinoma and 1 of which were for high grade dysplasia. 16 (41%) achieved CR after a mean of 2 more colonoscopies (range 1-4), 7(18%) are actively undergoing further EMR, and 4 were lost to follow-up.Figure 1Table 1: Demographics, endoscopic findings and pathology of patients with complete and incomplete resections.Conclusion: In this single center US experience, IR of large colon polyps occurred infrequently. Polyps > 40mm, piecemeal resections and difficulty lifting were risk factors for IR. Primary resections by specialist endoscopists reduce the risk of IR and the number of procedures to achieve CR.