Large Sessile Colonic Polyps Research Articles

Su1490 Endoscopic Mucosal Resection of Large Sessile Colonic Polyps: A Safe and Effective Alternative to Surgery

Endoscopic mucosal resection (EMR) has emerged as an alternative to surgery for large sessile lesions of the colon. There is currently limited data of this procedure and our aim was to evaluate the safety and efficacy of EMR by determining the success and complication rates in our population.

Mo1408 Advanced Polyps and Adjuvant APC- Time for a Rethink?

Advanced Polyps and Adjuvant APCTime for a Rethink? Patrick Wilson*, Olga Niewiadomski, David Devonshire, Michael Swan, Malcolm B. Barnes MMC Melbourne, Melbourne, VIC, Australia Introduction: Large colonic polyps follow a well-defined pathway of progression to carcinoma. Endoscopic mucosal resection (EMR) has been widely adopted and is minimally invasive and cost effective compared to surgery. However, recurrence following EMR of large colorectal lesions occurs in between 10-50% of cases at follow up within 12 months; this is likely due to remnant or residual tissue. Argon plasma coagulation (APC) is an ablative technique that may reduce recurrence rates following EMR, to 10-14%, (1). Aim: To assess the efficacy and safety of adjuvant APC to reduce the recurrence rate of large colorectal lesions ( 15mm) undergoing endoscopic resection. Methods: Data was prospectively collected over an 8 year period (from Jan 2003 to November 2011) on patients with large laterally spreading colorectal polyps ( 15mm) undergoing EMR. The procedure was done by 3 endoscopists using saline/adrenaline/indigo carmine submucosal injection followed by endoscopic mucosal resection. APC (40 watts proximal colon and 20 watts distal colon) was applied to the edge of the mucosal defect in all cases of complete endoscopic resection and to the edges and residual tissue in cases of incomplete resection. Endoscopic follow-up was performed by 12 months to assess for local recurrence, with biopsies taken if there was suspicion of recurrence. Results: A total of 178 patients, mean age of 72, had 188 polyps. 88% had complete initial resection, 12% were incomplete resections. Operative management was required in 8 cases (4.6% of cases) following the initial colonoscopy (7 due to advanced pathology and 1 due to perforation). Adenocarcinoma was found in 14 polyps, half were treated successfully endoscopically. Follow up data is currently available in 72 patients (78 polyps), a mean of 9 months later. The overall recurrence rate was 17%, for complete initial resection the recurrence rate was 9%, %, for incomplete resection the rate was 38%. Conclusion: Although the use of APC in this setting is not a new concept, there remains a question over its safety and effectiveness, and it is not yet standard of care in many institutions. The data we present show that in this institution adjuvant APC is safe (perforation and bleeding rates were similar to rates for polypectomy alone (2). The recurrence rate of polyps that have been fully excised at initial polpectomy is lower than rates often quoted (2). Even in polyps not expected to be cleared due to unfavorable morphology and histology, resection was complete in over 60%

Tu1454 Safety of Endoscopic Mucosal Resection (EMR) of Large Sessile Colon Polyps: Size and Location Matters

demands from health authorities and the public regarding physician training in general. There are however very little actual quantitative data regarding the contribution of simulator training to the early learning curve of novice endoscopists. Objective The aim of this study therefore was to assess the performance of novice endoscopists during patient-based colonoscopy after intensive and prolonged training on a virtual reality endoscopy simulator.DesignTrainees without any endoscopic experience were included in the study. They were divided into two groups. The simulator-training program consisted of either 50 or 100 virtual-reality colonoscopies on the GI Mentor II simulator (Simbionix, Israel). After 10, 30 and 50 virtual colonoscopies in the first group and after 20, 60 and 100 virtual colonoscopies in the second group, trainees were assessed both simulator-based (SBA) and patient-based (PBA). At each PBA 2 single-handed colonoscopies were performed with a 20-minute time limit. Objective assessment consisted of the time to reach the cecum, or the maximum distance from the anal verge after fully straightening the colonoscope. Subjective assessment was done by two independent expert endoscopists using tri-split video assessment including camera view, endoscope view, and ScopeGuide magnetic imaging view. Results Eighteen novices participated in the study. All participants completed virtual training and assessments. The mean cecal intubation time on the SBA improved from baseline 7.08 to 2.08 minutes at completion of the training (P 0.007). Colonic insertion depth during PBA improved from 37 to 60 cm (P 0.002). The learning effect of simulator training slowed down after 60 simulator colonoscopies. The cecum was intubated 4 times by 3 novices, during 2nd PBA (n 1), and during the final PBA (n 3) (P 0.11). Subjective PBA demonstrated a general increase in the efficiency of movements, instrument handling and planned endoscopy. Measured on a 5 point scale, performance significantly improved from 1.67 to 2.20 (P 0.02) Conclusion Virtual reality training on the GI Mentor II simulator leads to a significant improvement of performance on the simulator itself and -more importantlyto significantly improved performances during patient-based colonoscopy. This study is the first to demonstrate the rationale for intensive simulator training in the early learning curve of novices performing colonoscopy.

Su1570 Incidence and Predictors of Residual Adenoma After Endoscopic Mucosal Resection (EMR) of Large Sessile Colon Polyps

Su1570 Incidence and Predictors of Residual Adenoma After Endoscopic Mucosal Resection (EMR) of Large Sessile Colon Polyps

Endoscopic Mucosal Resection Outcomes and Prediction of Submucosal Cancer From Advanced Colonic Mucosal Neoplasia

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. 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. 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. 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.

Succinylated Gelatin for Submucosal Injection of Large Sessile Colon Polyps

Large sessile colon polyps are usually considered the most technically challenging type of polyp to remove. Injecting submucosal fluid to create a

S1527: Lesion Morphology, Paris Classification and Pit Pattern but Not Size Predict and Stratify Risk of Submucosal Invasive Adenocarcinoma Within Laterally Spreading Tumors (LSTs) and Large Sessile Colonic Polyps in a Multicenter Setting: Results of the Australian Colonic Endoscopic Mucosal Resection (ACE) Study

S1527: Lesion Morphology, Paris Classification and Pit Pattern but Not Size Predict and Stratify Risk of Submucosal Invasive Adenocarcinoma Within Laterally Spreading Tumors (LSTs) and Large Sessile Colonic Polyps in a Multicenter Setting: Results of the Australian Colonic Endoscopic Mucosal Resection (ACE) Study

347h: Predictors of Therapeutic Success for Endoscopic Mucosal Resection (EMR) of Laterally Spreading Tumours (LSTs) and Large Sessile Colonic Polyps: Results of the Prospective, Multicenter Australian Colonic EMR (ACE) Study

347h: Predictors of Therapeutic Success for Endoscopic Mucosal Resection (EMR) of Laterally Spreading Tumours (LSTs) and Large Sessile Colonic Polyps: Results of the Prospective, Multicenter Australian Colonic EMR (ACE) Study

W1447: Endoscopic Mucosal Resection and Modified Endoscopic Submucosal Dissection for Removal of Large Sessile Colonic Polyps: 1-Year Single Operator Experience in the USA

Development of endoscopic submucosal dissection (ESD) in Japan enabled endoscopic removal of large sessile and flat colonic polyps. However, ESD technique is difficult and requires accessories which are not readily available in the USA.

CURRENT STATUS OF COLONIC ENDOSCOPIC MUCOSAL RESECTION IN THE WEST AND THE INTERFACE WITH ENDOSCOPIC SUBMUCOSAL DISSECTION

Endoscopic Mucosal Resection (EMR) is now widely practised by western endoscopists to treat large sessile colonic polyps or laterally spreading tumours. Despite its widespread application, the technique of colonic EMR is not standardised. A lesion specific endoscopic treatment approach is also lacking. For lesions larger than 25mm, EMR is limited by its inability to achieve en-bloc resection. En-bloc resection has many theoretical advantages including more accurate histological assessment, reduced recurrence and potentially curative treatment for low risk submucosal invasive neoplasia particularly in patients with significant co-morbidity. Hence, Japanese endoscopists, having pioneered endoscopic submucosal dissection (ESD) in the upper gastrointestinal tract for the en-bloc resection of superficial neoplasia, now advocate the use of ESD for laterally spreading tumours of the colon greater than 25-30mm. This treatment strategy is not widely accepted or practised in the west and has its own inherent problems. The absence of suitable gastric lesions on which to develop ESD skills is also another significant barrier to the development of colonic ESD. It is also possible that modification and refinement in EMR technique may increase the size limit for colonic EMR.

Work and Resources Needed for Endoscopic Resection of Large Sessile Colorectal Polyps

Large sessile colon polyps often are referred for surgical resection, even when amenable to endoscopic resection. The aim of this study was to describe the resource use of endoscopic resection of large sessile colon polyps compared with small polyps with respect to physician time and equipment use. Retrospectively, procedure time, medication use, and equipment use were recorded for 184 consecutive patients with sessile colorectal polyps 2 cm or larger in size and for 184 consecutive control patients with only sessile polyps less than 2 cm in size or pedunculated polyps. The mean duration of colonoscopy in patients with large sessile colon polyps averaged 51.4 (SD, 25.6) minutes compared with 20.0 (SD, 8.6) minutes for the control group (P < .0001). The large-polyp group required much more equipment to complete the polypectomy (eg, injection catheters and cautery probes) (P < .0001). Our results indicate that the costs of endoscopic large sessile adenoma resection in physician work and equipment are substantially greater than the costs of resection of small adenomas. These costs may be a deterrent to endoscopic resection of large sessile adenomas and may warrant increased reimbursement for those procedures, particularly if predictions that colonoscopic procedures will become more complex in the future are realized.

Polypectomy devices

Polypectomy devices

Resources Required for Resection of Large Sessile Colon Polyps

Background: Large sessile colon polyps (≥2 cm) (LSP) are often referred for surgery. This may be due to risk of bleeding and perforation in removal of LSP when compared to small polyps. High costs, procedure time and accessory use may also be a deterrent to endoscopic resection. Objective: To describe the resource utilization during endoscopic resection of LSP. Design: Procedure time, medication use, accessory use, and recovery time were recorded for 184 consecutive patients with LSP. Controls were 184 consecutive patients with resection of only sessile polyps ≤ 2 cm in size or pedunculated polyps. Results: Colonoscopy in patients with LSP averaged 51.4 min compared to 20.0 min for the control group (p < 0.0001). Recovery time was 31.6 min for the LSP group compared to 24.8 min for the controls (p < 0.0001). 62.5% of patients in the LSP group were referred LSP removal by another endoscopist. Time in procedure for referred patients with LSP was 55.4 min vs. 44.3 min for non-referred patients with LSP. Polypectomy technique and use of devices differed between the two groups. In the LSP group, hot snare (95% vs 20%; p < 0.0001), submucosal injection (80% vs 2%; p < 0.0001), piecemeal technique, India Ink and ablation techniques were more frequently used, while the control group had cold snare and cold forceps utilized more often (all p < 0.0001). Comparing referred LSP removals to the non-referred cases, submucosal injection was used in more of the referred cases (86% vs 71%; p = 0.0161). Ablative techniques (usually argon plasma coagulation) were used for some part of the LSP in 75% of the referred group compared to 52% of the non- referred group (p = 0.0008). No other differences between referred and non-referred groups were found. Conclusions: Since reimbursement for resection of LSP is not substantially greater than for small polyps, the long procedure time required for resection of large sessile colon polyps and the large amount of ancillary equipment needed are likely deterrents to endoscopic resection. To facilitate increased use of endoscopic resection of LSP, technical developments that reduce the expertise, risk and time required for endoscopic resection, and higher reimbursement are needed.

Colonoscopic Polypectomy in Retroflexion

Background: Large sessile colon polyps present difficulty for endoscopists, because they are associated with the greatest risk from endoscopic resection, and because resection is time consuming, costly and technically difficult. One factor that creates technical difficulty is when all or a portion of the polyp is hard-to-access endoscopically. Little has been written about the value of retroflexion in the removal of hard-to-access large sessile colon polyps proximal to the rectum. Methods: We recorded the frequency with which retroflexion was needed in the removal of 59 consecutive sessile colon polyps 2 cm or larger located proximal to the rectum. All 59 polyps were removed using prototype colonoscopes with short bending sections that facilitate retroflexion. Results: Fourteen polyps were removed entirely (n = 4) or partially (n = 10) in retroflexion. Polyps that were removed in retroflexion were more likely to have been referred by another colonoscopist (14/49) compared to those initially discovered by the author during screening or diagnostic colonoscopy (0/10; p = 0.05). There were no perforations and no complications related to retroflexion. Conclusions: Retroflexion is a useful adjunctive procedure for removal of some large sessile colon polyps proximal to the rectum that are difficult to access endoscopically. This may be particularly true in a colonoscopic practice that accepts referrals of polyps from other endoscopists. Background: Large sessile colon polyps present difficulty for endoscopists, because they are associated with the greatest risk from endoscopic resection, and because resection is time consuming, costly and technically difficult. One factor that creates technical difficulty is when all or a portion of the polyp is hard-to-access endoscopically. Little has been written about the value of retroflexion in the removal of hard-to-access large sessile colon polyps proximal to the rectum. Methods: We recorded the frequency with which retroflexion was needed in the removal of 59 consecutive sessile colon polyps 2 cm or larger located proximal to the rectum. All 59 polyps were removed using prototype colonoscopes with short bending sections that facilitate retroflexion. Results: Fourteen polyps were removed entirely (n = 4) or partially (n = 10) in retroflexion. Polyps that were removed in retroflexion were more likely to have been referred by another colonoscopist (14/49) compared to those initially discovered by the author during screening or diagnostic colonoscopy (0/10; p = 0.05). There were no perforations and no complications related to retroflexion. Conclusions: Retroflexion is a useful adjunctive procedure for removal of some large sessile colon polyps proximal to the rectum that are difficult to access endoscopically. This may be particularly true in a colonoscopic practice that accepts referrals of polyps from other endoscopists.

Endoscopic resection of large sessile colonic polyps by specialist and non-specialist endoscopists.

Patients with large sessile colonic polyps for which endoscopic resection might be feasible are often referred directly for operation. The aim of this study was to determine the outcome of patients with such polyps diagnosed by specialist and non-specialist colonoscopists. Patients with large (greater than 2 cm) sessile polyps detected at colonoscopy from January 1995 to July 2000 were identified. Resection technique and clinical and endoscopic outcomes were recorded. Two of the colonoscopists (B.P.S., C.B.W.) are recognized as specialists. Some 130 polyps were identified, 100 detected by either of two specialist endoscopists (including 14 cancers) and 30 by 14 non-specialist endoscopists (including ten cancers). Endoscopic resection of benign polyps was attempted by experts in 80 (93 per cent) of 86 cases and by non-experts in 15 of 20 cases (P = 0.03), with successful management by endoscopy alone in 61 (76 per cent) of 80 and in six of 15 cases respectively (P = 0.01). Complications occurred following three polypectomies performed by an expert (bleeding, two; pain, one) and one by a non-expert (bleeding). The estimated end-cost of management by specialists was less than half of that by non-specialists. Endoscopic resection of large sessile colonic polyps is feasible in the majority of patients and should be considered as first-line therapy. Prompt referral to a specialist endoscopist may improve outcomes by avoiding operation or enabling complete excision at a single endoscopy session.

Treatment with argon plasma coagulation reduces recurrence after piecemeal resection of large sessile colonic polyps: A randomized trial and recommendations

Background: Recurrence is frequent after piecemeal snare resection of large sessile colorectal polyps. The aim of this study was to evaluate the safety and efficacy of argon plasma coagulation (APC) in preventing recurrence when applied to the edge and base of the polypectomy site after apparently complete piecemeal resection. Methods: Patients with large (>1.5 cm) sessile polyps removed by piecemeal snare cautery were placed into 2 groups. The first consisted of patients with polyps believed by the endoscopist to be completely excised. These patients were randomized to either no further therapy (control) or to APC of the rim and any residual mucosal or submucosal tissue in the base of the polypectomy site. The second group comprised patients in whom polyps, as judged by the endoscopist, were incompletely excised by snare polypectomy; APC was routinely applied without randomization to all visible remaining adenomatous tissue. Follow-up colonoscopy was performed within 3 months and 1 year; biopsy specimens were taken routinely from the resection site and further polypectomy was performed as indicated. Results: There were fewer recurrences after APC in the randomized group (1/10 APC, 7/11 no APC; p = 0.02). In the group with initial incomplete snare polypectomy, recurrence was detected at 3 months in 6 of 13 despite APC. One patient was hospitalized with abdominal pain and minor rectal bleeding but required no intervention. There were no other episodes of significant late bleeding caused by piecemeal polypectomy. One patient was referred for surgery after unsuccessful endoscopic management. Conclusions: In patients with apparent complete endoscopic snare resection of large adenomas, postpolypectomy application of APC reduces adenomatous recurrence. (Gastrointest Endosc 2002;55:371-5.)

Twin-endoscope scissors resection (T-ESR): a new minimally invasive technique for performing colonic mucosectomy.

Piecemeal resection is currently the safest method for the endoscopic removal of large sessile colonic polyps. However, this method has its limitations, including the quality of the specimen received for histopathology and the need for early follow-up due to the possibility of incomplete resection and recurrence. New methods enabling en bloc resection would be advantageous in these respects. We developed a new technique that uses endoscopic scissors and two endoscopes to perform mucosal resection in a porcine model. So far, the technique has been evaluated in two animals. The resection of intact mucosal specimens measuring 1.5 x 1 cm and 2.2 x 3.5 cm was achieved, with no procedural or late hemorrhage and no clinical or radiological evidence of perforation. After further development and evaluation, this technique should be suitable for the resection of large sessile colonic polyps in humans.

Large sessile and broad-based colonic polyps. Outcomes of endoscopic therapy are better in expert hands

Large sessile and broad-based colonic polyps. Outcomes of endoscopic therapy are better in expert hands

3500 Argon plasma coagulation assisted resection of large sessile colonic polyps: a randomised trial.

BACKGROUND: Large sessile adenomas account for up to 3.7% of polyps found at colonoscopy. Removal by piecemeal snare excision and EMR techniques is widely practised, but recurrence is reported in up to 28%, probably because of residual foci of adenoma tissue. AIMS: To evaluate the safety and efficacy (recurrence rate) of APC when combined with piecemeal resection of large sessile polyps. METHODS: Consecutive patients with large sessile polyps requiring piecemeal resection were placed into two groups depending on the endoscopist's assessment of completeness of excision. If complete excision was not possible with the snare alone, APC was applied. If complete excision was achieved, the patient was randomised to APC or no-APC. The procedures were performed by 2 experienced endoscopists (BPS & CBW). APC was set at 65W power, and applied to the polypectomy base and margin. Patients were contacted at 2 weeks, and followed up endoscopically at 6-12 weeks and 1 year. At follow-up, biopsies were taken from the polypectomy site and any recurrent adenoma was resected and treated with APC. RESULTS: 13 patients have had at least one follow up endoscopy, table 1. At initial polypectomy 5 had minor procedural bleeding (3 in APC patients) which settled with topical adrenaline (3) or spontaneously (2). 1 patient had minor bleeding and another had fever for 24 hours after APC had been used for recurrence at follow up. There were no major complications. No polyps have needed surgical excision. CONCLUSIONS: APC appears safe and may help to reduce recurrence of large sessile polyps after piecemeal resection.

Piecemeal snare excision of large sessile colon and rectal polyps: Is it adequate?

This study analyzes 28 consecutive patients with large sessile polyps snared piecemeal from the colon and rectum. The sections were examined to determine the adequacy of orientation and margin of excision. Orientation was judged excellent in five, good in 12, fair in six, and poor in five cases. The margin of excision was judged adequate in 23 of 28 cases. Five of eight patients with invasive carcinoma underwent bowel resection, and no residual tumor was found in the resected specimens. Of the remaining 20 patients without carcinoma, five had residual tumor or recurrences, with follow-up from 6 months to 6 years (average, 18 months). All of them underwent rebiopsies and electrocoagulation. None of the residual tumor or recurrences showed evidence of malignancy. Piecemeal snare excision of large sessile polyps of the large bowel appears to be an adequate procedure for most patients. A close follow-up with colonoscopy or proctoscopy is essential because residual tumor or recurrences are common.