- Email: [email protected]
Tu1454 Safety of Endoscopic Mucosal Resection (EMR) of Large Sessile Colon Polyps: Size and Location Matters
Abstracts
virtual reality, the introduction of competency models in GI training, and 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 importantly- to 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.
Tu1454 Safety of Endoscopic Mucosal Resection (EMR) of Large Sessile Colon Polyps: Size and Location Matters Sachin B. Wani, Christine E. Hovis, Taylor Geisman, Navya D. Kanuri, Vladimir M. Kushnir, Daniel Mullady, Faris Murad, Dayna S. Early, Sreenivasa S. Jonnalagadda, Steven A. Edmundowicz, Riad R. Azar Washington University School of Medicine, University City, MO Background: Variable rates of complications have been reported following EMR of large sessile colon polyps. Aims: In a cohort of pts undergoing EMR of large sessile polyps to describe: 1)prevalence of cancer 2)frequency of complications 3)predictors of complications.Methods: Pts undergoing EMR of large sessile polyps (ⱖ2cm) at a tertiary referral ctr by 3 experienced interventional endoscopists were identified. Pedunculated polyps were excluded. Polyps were resected en bloc or piecemeal; argon plasma coagulation (APC) was used to ablate any residual polyp. Complications were: procedural and post-procedural [bleeding, perforation, post-polypectomy syndrome (PPS)]. Bleeding was defined as: need for intervention during procedure, hematochezia and repeat colonoscopy. Demographics, location (right vs. left), and polyp histology were noted. To compare pts with and without complications, univariate analyses were performed using Student’s t- and Chi-square test. Significant variables were then placed into a generalized estimating equation model to identify independent predictors. Results: From 2006-2010, 218 pts with 248 polyps [mean age 65.8 yrs, BMI 29.9, mean size of polyp 29.9mm (SD 10.7, range 20-90mm)] were included. APC was used in 41.5%, prophylactic hemoclips in 16.1% of polyps. 79% of the polyps were right sided. Histology was tubular adenoma 34%, tubulovillous adenoma 49%, serrated adenoma 5%, and hyperplastic 6%. Prevalence of cancer in this cohort was 6% (n⫽16). High-grade dysplasia (HGD) was present in 43 (17.3%) polyps. Complication rates were extracted on data from 292 EMRs (248 index, 44 f/u). There were 19 procedural complications [bleeding 17 (5.8%) and perforation 2 (0.7%)] and post-procedural in 31 [post-polypectomy bleeding 28 (9.6%), perforation 2 (0.7%) and PPS 1 (0.3%)]. In post-polypectomy bleeding, mean time to presentation was 3.8 days (SD 3.7), 46% required blood transfusion, 18% required ICU admission, repeat colonoscopy in 89%, and average length of hospital stay 2.89 days. 3/4 perforations were managed endoscopically. On univariate analysis, factors associated with complications were: size (34.8 vs. 29.6 mm, p⫽0.018) and location (right 19.1% vs. left 3.3%, p⫽0.002). There was no difference in the complication rates based on use of APC, prophylactic hemoclips and final histology. On multivariate analysis, polyp size (increase by 5 mm) [OR 1.04 (95% CI 1.01-1.06), p⫽0.005] and right sided location [OR 1.2 (1.1-1.3), p⬍0.001] were significant predictors. Conclusions: EMR of large sessile colon polyps is associated with an overall complication rate of ⬃16%. Size of polyp and right-sided location were the most significant predictors of complications. Prevalence of cancer in this large cohort was low (⬃6%). Endoscopists need to be cognizant of these complication rates to anticipate their rapid identification and management.
www.giejournal.org
Tu1455 Comparison of Physician, Endoscopic and Patient Characteristics Between High and Low Polyp Detectors Shiva K. Ratuapli, Suryakanth Gurudu, Russell I. Heigh, Jonathan A. Leighton, Michael D. Crowell Gastroenterology, Mayo Clinic Arizona, Scottsdale, AZ Background: Prevention of colorectal cancer depends on the timely detection and removal of adenomatous colon polyps. While the adenoma detection rate (ADR) is a frequently used quality measure for colonoscopy, the overall polypectomy rate (PR) has recently been suggested as another quality indicator because it is easy to measure and has good correlation with the ADR. However, the PR varies widely among endoscopists, and the factors leading to this variation are not entirely known. Aim: To compare endoscopic, patient and physician characteristics between endoscopists with a high PR and a low PR. Methods: A retrospective chart review was completed for all patients who underwent colonoscopy between January and December 2009. Colonoscopy performed for anemia, bleeding and/or inflammatory bowel disease was excluded. The ADR was defined as the detection of at least one adenoma per colonoscopy, and the PR was defined as the proportion of procedures in which at least one polyp was removed. Based on recent studies, a 40% PR was determined to correspond to the benchmark ADR of 25%. ADR and PR for individual endoscopists were calculated, and endoscopists were categorized into two groups: a) Low PR ⱕ 40% b) high PR ⱖ 40%. Demographic, endoscopic and physician factors were compared between the two groups using chi-square, ttests, and generalized linear models to control for clustered data. Data are presented as mean ⫾ SD and proportions, in the format: (low PR vs high PR). Results: Data were collected from 4574 colonoscopies performed by 19 endoscopists. Physician factors did not differ significantly between low PR and high PR groups: experience (17⫾10 vs 14⫾7 yrs, P⫽0.46), colonoscopy volume (211⫾107 vs 273⫾104, P⫽0.21) and endoscopists’ gender (70% M vs 89% M, P⫽0.58). The patient sample did not differ in age (62 ⫾ 12 vs 62 ⫾ 12 yrs, P ⫽ 0.434) or BMI (29 ⫾ 23 vs 28 ⫾ 10, P⫽0.41), but included more males (48% vs 53%, P⬍0.001) in the high PR group. The proportion of patients with good tolerance (80% vs 83%, P⬍0.001) and good quality of bowel preparation (92% vs 88%, P ⬍0.001) were significantly different between two groups, but there was no significant difference in incomplete colonoscopies (6% vs 7%, P ⫽0.11) or the largest size of resected polyps (6⫾13 vs 6⫾7mms, P⫽0.53). The ADR (21% vs 30%, P⬍0.001) and withdrawal time (9 ⫾ 6 vs 13 ⫾ 8 mins, P⬍0.001) were significantly lower in the low PR group compared to high PR group. Conclusion: Data from this large patient sample showed that higher polypectomy rates among endoscopists were associated with better patient tolerance, male patient population and longer withdrawal times. Further prospective studies are needed to confirm our findings and derive the factors needed to improve adenoma and polyp detection.
Tu1456 Deconstructing the Colonoscopic Examination: Preliminary Results Comparing Expert and Novice Kinematic Profiles in Screening Colonoscopy Inbar S. Spofford1,2, Nitin Kumar2, Keith L. Obstein3, Balazs I. Lengyel4, Jagadeesan Jayender4,5, Kirby G. Vosburgh6, Christopher C. Thompson2 1 Division of Pediatric Gastroenterology, Massachusetts General Hospital, Boston, MA; 2Division of Gastroenterology, Brigham & Women’s Hospital, Boston, MA; 3Division of Gastroenterology, Vanderbilt University Medical Center, Nashville, TN; 4Surgical Planning Laboratory, Brigham & Women’s Hospital, Boston, MA; 5 CIMIT, Massachusetts General Hospital, Boston, MA; 6Division of Radiology, Brigham & Women’s Hospital, Boston, MA Background/Aim: There is no widely used tool for colonoscopy training or quantitative assessment of endoscopic skill. Our group has shown that kinematic data is effective in assessing endoscopist performance and in differentiating skill level in a colon model. To deconstruct the colonoscopic exam and quantitatively segregate experts and novices through kinematic analysis. Methods: Four sensors were attached along a variable stiffness pediatric or adult colonoscope at the tip (1), 10cm (2), 30cm (3), and 55cm (4). Three expert endoscopists (attendings, ⬎3500 colonoscopies) and 2 novices (fellows, ⬍400) performed 9 screening colonoscopies. Kinematic data (path length, flex, velocity, acceleration, jerk, tip angulation, angular velocity, rotation, curvature, time to cecum) was obtained from insertion to visualization of the cecum. Endoscopists rated procedure difficulty with a Visual Analog Scale (VAS) and NASA Task Load Index (TLI). Outcomes were compared using the Wilcoxon-Mann-Whitney two-sample ranksum test. Correlations were performed with Spearman’s rank correlation. Results: Experts had significantly reduced path length in sensors 3 (PL3) and 4 (PL4) (p⫽0.03), which are closest to the endoscopist’s hand, and lower mean jerk in 2 of 4 sensors (p⫽0.03). There was a trend towards less scope flex, decreased mean acceleration in 2 of 4 sensors (p⫽0.09), and less time to reach the cecum (T) in the expert group (median 550 sec, 210-1069) versus novices (median 1181
Volume 73, No. 4S : 2011
GASTROINTESTINAL ENDOSCOPY
AB415
virtual reality, the introduction of competency models in GI training, and 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 importantly- to 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.
Tu1454 Safety of Endoscopic Mucosal Resection (EMR) of Large Sessile Colon Polyps: Size and Location Matters Sachin B. Wani, Christine E. Hovis, Taylor Geisman, Navya D. Kanuri, Vladimir M. Kushnir, Daniel Mullady, Faris Murad, Dayna S. Early, Sreenivasa S. Jonnalagadda, Steven A. Edmundowicz, Riad R. Azar Washington University School of Medicine, University City, MO Background: Variable rates of complications have been reported following EMR of large sessile colon polyps. Aims: In a cohort of pts undergoing EMR of large sessile polyps to describe: 1)prevalence of cancer 2)frequency of complications 3)predictors of complications.Methods: Pts undergoing EMR of large sessile polyps (ⱖ2cm) at a tertiary referral ctr by 3 experienced interventional endoscopists were identified. Pedunculated polyps were excluded. Polyps were resected en bloc or piecemeal; argon plasma coagulation (APC) was used to ablate any residual polyp. Complications were: procedural and post-procedural [bleeding, perforation, post-polypectomy syndrome (PPS)]. Bleeding was defined as: need for intervention during procedure, hematochezia and repeat colonoscopy. Demographics, location (right vs. left), and polyp histology were noted. To compare pts with and without complications, univariate analyses were performed using Student’s t- and Chi-square test. Significant variables were then placed into a generalized estimating equation model to identify independent predictors. Results: From 2006-2010, 218 pts with 248 polyps [mean age 65.8 yrs, BMI 29.9, mean size of polyp 29.9mm (SD 10.7, range 20-90mm)] were included. APC was used in 41.5%, prophylactic hemoclips in 16.1% of polyps. 79% of the polyps were right sided. Histology was tubular adenoma 34%, tubulovillous adenoma 49%, serrated adenoma 5%, and hyperplastic 6%. Prevalence of cancer in this cohort was 6% (n⫽16). High-grade dysplasia (HGD) was present in 43 (17.3%) polyps. Complication rates were extracted on data from 292 EMRs (248 index, 44 f/u). There were 19 procedural complications [bleeding 17 (5.8%) and perforation 2 (0.7%)] and post-procedural in 31 [post-polypectomy bleeding 28 (9.6%), perforation 2 (0.7%) and PPS 1 (0.3%)]. In post-polypectomy bleeding, mean time to presentation was 3.8 days (SD 3.7), 46% required blood transfusion, 18% required ICU admission, repeat colonoscopy in 89%, and average length of hospital stay 2.89 days. 3/4 perforations were managed endoscopically. On univariate analysis, factors associated with complications were: size (34.8 vs. 29.6 mm, p⫽0.018) and location (right 19.1% vs. left 3.3%, p⫽0.002). There was no difference in the complication rates based on use of APC, prophylactic hemoclips and final histology. On multivariate analysis, polyp size (increase by 5 mm) [OR 1.04 (95% CI 1.01-1.06), p⫽0.005] and right sided location [OR 1.2 (1.1-1.3), p⬍0.001] were significant predictors. Conclusions: EMR of large sessile colon polyps is associated with an overall complication rate of ⬃16%. Size of polyp and right-sided location were the most significant predictors of complications. Prevalence of cancer in this large cohort was low (⬃6%). Endoscopists need to be cognizant of these complication rates to anticipate their rapid identification and management.
www.giejournal.org
Tu1455 Comparison of Physician, Endoscopic and Patient Characteristics Between High and Low Polyp Detectors Shiva K. Ratuapli, Suryakanth Gurudu, Russell I. Heigh, Jonathan A. Leighton, Michael D. Crowell Gastroenterology, Mayo Clinic Arizona, Scottsdale, AZ Background: Prevention of colorectal cancer depends on the timely detection and removal of adenomatous colon polyps. While the adenoma detection rate (ADR) is a frequently used quality measure for colonoscopy, the overall polypectomy rate (PR) has recently been suggested as another quality indicator because it is easy to measure and has good correlation with the ADR. However, the PR varies widely among endoscopists, and the factors leading to this variation are not entirely known. Aim: To compare endoscopic, patient and physician characteristics between endoscopists with a high PR and a low PR. Methods: A retrospective chart review was completed for all patients who underwent colonoscopy between January and December 2009. Colonoscopy performed for anemia, bleeding and/or inflammatory bowel disease was excluded. The ADR was defined as the detection of at least one adenoma per colonoscopy, and the PR was defined as the proportion of procedures in which at least one polyp was removed. Based on recent studies, a 40% PR was determined to correspond to the benchmark ADR of 25%. ADR and PR for individual endoscopists were calculated, and endoscopists were categorized into two groups: a) Low PR ⱕ 40% b) high PR ⱖ 40%. Demographic, endoscopic and physician factors were compared between the two groups using chi-square, ttests, and generalized linear models to control for clustered data. Data are presented as mean ⫾ SD and proportions, in the format: (low PR vs high PR). Results: Data were collected from 4574 colonoscopies performed by 19 endoscopists. Physician factors did not differ significantly between low PR and high PR groups: experience (17⫾10 vs 14⫾7 yrs, P⫽0.46), colonoscopy volume (211⫾107 vs 273⫾104, P⫽0.21) and endoscopists’ gender (70% M vs 89% M, P⫽0.58). The patient sample did not differ in age (62 ⫾ 12 vs 62 ⫾ 12 yrs, P ⫽ 0.434) or BMI (29 ⫾ 23 vs 28 ⫾ 10, P⫽0.41), but included more males (48% vs 53%, P⬍0.001) in the high PR group. The proportion of patients with good tolerance (80% vs 83%, P⬍0.001) and good quality of bowel preparation (92% vs 88%, P ⬍0.001) were significantly different between two groups, but there was no significant difference in incomplete colonoscopies (6% vs 7%, P ⫽0.11) or the largest size of resected polyps (6⫾13 vs 6⫾7mms, P⫽0.53). The ADR (21% vs 30%, P⬍0.001) and withdrawal time (9 ⫾ 6 vs 13 ⫾ 8 mins, P⬍0.001) were significantly lower in the low PR group compared to high PR group. Conclusion: Data from this large patient sample showed that higher polypectomy rates among endoscopists were associated with better patient tolerance, male patient population and longer withdrawal times. Further prospective studies are needed to confirm our findings and derive the factors needed to improve adenoma and polyp detection.
Tu1456 Deconstructing the Colonoscopic Examination: Preliminary Results Comparing Expert and Novice Kinematic Profiles in Screening Colonoscopy Inbar S. Spofford1,2, Nitin Kumar2, Keith L. Obstein3, Balazs I. Lengyel4, Jagadeesan Jayender4,5, Kirby G. Vosburgh6, Christopher C. Thompson2 1 Division of Pediatric Gastroenterology, Massachusetts General Hospital, Boston, MA; 2Division of Gastroenterology, Brigham & Women’s Hospital, Boston, MA; 3Division of Gastroenterology, Vanderbilt University Medical Center, Nashville, TN; 4Surgical Planning Laboratory, Brigham & Women’s Hospital, Boston, MA; 5 CIMIT, Massachusetts General Hospital, Boston, MA; 6Division of Radiology, Brigham & Women’s Hospital, Boston, MA Background/Aim: There is no widely used tool for colonoscopy training or quantitative assessment of endoscopic skill. Our group has shown that kinematic data is effective in assessing endoscopist performance and in differentiating skill level in a colon model. To deconstruct the colonoscopic exam and quantitatively segregate experts and novices through kinematic analysis. Methods: Four sensors were attached along a variable stiffness pediatric or adult colonoscope at the tip (1), 10cm (2), 30cm (3), and 55cm (4). Three expert endoscopists (attendings, ⬎3500 colonoscopies) and 2 novices (fellows, ⬍400) performed 9 screening colonoscopies. Kinematic data (path length, flex, velocity, acceleration, jerk, tip angulation, angular velocity, rotation, curvature, time to cecum) was obtained from insertion to visualization of the cecum. Endoscopists rated procedure difficulty with a Visual Analog Scale (VAS) and NASA Task Load Index (TLI). Outcomes were compared using the Wilcoxon-Mann-Whitney two-sample ranksum test. Correlations were performed with Spearman’s rank correlation. Results: Experts had significantly reduced path length in sensors 3 (PL3) and 4 (PL4) (p⫽0.03), which are closest to the endoscopist’s hand, and lower mean jerk in 2 of 4 sensors (p⫽0.03). There was a trend towards less scope flex, decreased mean acceleration in 2 of 4 sensors (p⫽0.09), and less time to reach the cecum (T) in the expert group (median 550 sec, 210-1069) versus novices (median 1181
Volume 73, No. 4S : 2011
GASTROINTESTINAL ENDOSCOPY
AB415