The 2023 top 10 list of endoscopy topics in medical publishing: an annual review by the American Society for Gastrointestinal Endoscopy Editorial Board.

Using a systematic literature search of original articles published during 2023 in Gastrointestinal Endoscopy (GIE) and other high-impact medical and gastroenterology journals, the GIE Editorial Board of the American Society for Gastrointestinal Endoscopy compiled a list of the top 10 most significant topic areas in general and advanced GI endoscopy during the year. Each GIE Editorial Board member was directed to consider 3 criteria in generating candidate topics-significance, novelty, and impact on global clinical practice-and subject matter consensus was facilitated by the Chair through electronic voting and a meeting of the entire GIE Editorial Board. The 10 identified areas collectively represent advances in the following endoscopic spheres: GI bleeding, endohepatology, endoscopic palliation, artificial intelligence and polyp detection, artificial intelligence beyond the colon, better polypectomy and EMR, how to make endoscopy units greener, high-quality upper endoscopy, endoscopic tissue apposition and closure devices, and endoscopic submucosal dissection. Each board member was assigned a topic area around which to summarize relevant important articles, thereby generating this overview of the "top 10" endoscopic advances of 2023.

The 2022 top 10 list of endoscopy topics in medical publishing: an annual review by the American Society for Gastrointestinal Endoscopy Editorial Board.

Using a systematic literature search of original articles published during 2022 in Gastrointestinal Endoscopy and other high-impact medical and gastroenterology journals, the 10-member Editorial Board of the American Society for Gastrointestinal Endoscopy composed a list of the 10 most significant topic areas in GI endoscopy during the study year. Each Editorial Board member was directed to consider 3 criteria in generating candidate lists-significance, novelty, and global impact on clinical practice-and subject matter consensus was facilitated by the Chair through electronic voting. The 10 identified areas collectively represent advances in the following endoscopic spheres: artificial intelligence, endoscopic submucosal dissection, Barrett's esophagus, interventional EUS, endoscopic resection techniques, pancreaticobiliary endoscopy, management of acute pancreatitis, endoscopic environmental sustainability, the NordICC trial, and spiral enteroscopy. Each board member was assigned a consensus topic area around which to summarize relevant important articles, thereby generating this précis of the "top 10" endoscopic advances of 2022.

Impact of topical budesonide on prevention of esophageal stricture after mucosal resection.

BACKGROUND AND AIMS: EMR and endoscopic submucosal dissection (ESD) are treatment modalities for Barrett's esophagus involving high-grade dysplasia or early cancer. Injectional corticosteroid therapy decreases the risk of procedure-related esophageal stricture (ES) formation. Our aim was to assess the efficacy of topical budesonide on the rate of ES formation after EMR or ESD. METHODS: Patients included prospectively from 3 tertiary endoscopy centers received 3 mg budesonide orally twice a day for 8 weeks after esophageal EMR or ESD of 50% or more of the esophageal circumference between January 1, 2014 and June 30, 2018. These patients were matched (1:3 ratio) retrospectively with a consecutive patient cohort who underwent EMR or ESD of 50% or more of the esophageal circumference without concomitant corticosteroid therapy. The primary endpoint was the presence of ES at the 12-week follow-up. RESULTS: Twenty-five patients (budesonide) were matched with 75 patients (no budesonide). Most underwent EMR for Barrett's esophagus with biopsy-proven high-grade dysplasia or suspected T1a cancer. Although most baseline characteristics did not differ significantly, patients in the budesonide cohort tended to have a higher proportion of circumferential EMR. The proportion of patients with ES was not significantly lower in the budesonide cohort (16% vs 28%). On logistic regression analysis, budesonide remained associated with a lower incidence of ES (P = .023); however, when controlling for baseline characteristics with a propensity score weighted logistic regression model, there was no significant effect on ES formation (P = .176). CONCLUSIONS: Topical budesonide might be associated with a reduction of ES after EMR or ESD; however, further studies are needed to verify our results.

Climate Change and Obesity.

Global warming and the rising prevalence of obesity are well described challenges of current mankind. Most recently, the COVID-19 pandemic arose as a new challenge. We here attempt to delineate their relationship with each other from our perspective. Global greenhouse gas emissions from the burning of fossil fuels have exponentially increased since 1950. The main contributors to such greenhouse gas emissions are manufacturing and construction, transport, residential, commercial, agriculture, and land use change and forestry, combined with an increasing global population growth from 1 billion in 1800 to 7.8 billion in 2020 along with rising obesity rates since the 1980s. The current Covid-19 pandemic has caused some decline in greenhouse gas emissions by limiting mobility globally via repetitive lockdowns. Following multiple lockdowns, there was further increase in obesity in wealthier populations, malnutrition from hunger in poor populations and death from severe infection with Covid-19 and its virus variants. There is a bidirectional relationship between adiposity and global warming. With rising atmospheric air temperatures, people typically will have less adaptive thermogenesis and become less physically active, while they are producing a higher carbon footprint. To reduce obesity rates, one should be willing to learn more about the environmental impact, how to minimize consumption of energy generating carbon dioxide and other greenhouse gas emissions, and to reduce food waste. Diets lower in meat such as a Mediterranean diet, have been estimated to reduce greenhouse gas emissions by 72%, land use by 58%, and energy consumption by 52%.

Low Frequency of Lymph Node Metastases in Patients in the United States With Early-stage Gastric Cancers That Fulfill Japanese Endoscopic Resection Criteria.

BACKGROUND & AIMS: In the West, early gastric cancer is increasingly managed with endoscopic resection (ER). This is, however, based on the assumption that the low prevalence and risk of lymph node metastases observed in Asian patients is applicable to patients in the United States. We sought to evaluate the frequency of and factors associated with metastasis of early gastric cancers to lymph nodes, and whether the Japanese ER criteria are applicable to patients in the US. METHODS: We performed a retrospective study of 176 patients (mean age 68.5 years; 59.1% male; 58.5% white) who underwent surgical resection with lymph node dissection of T1 and Tis gastric adenocarcinomas, staged by pathologists, at 7 tertiary care centers in the US from January 1, 1999, through December 31, 2016. The frequency of lymph node metastases and associated risk factors were determined. RESULTS: The mean size of gastric adenocarcinomas was 23.0 ± 16.6 mm-most were located in the lower-third of the stomach (67.0%), invading the submucosa (55.1%), and moderately differentiated (31.3%). Lymphovascular invasion was observed in 18.2% of lesions. Overall, 20.5% of patients had lymph node metastases. Submucosal invasion (odds ratio, 3.9; 95% CI, 1.4-10.7) and lymphovascular invasion (odds ratio, 4.6; 95% CI, 1.8-12.0) were independently associated with increased risk of metastasis to lymph nodes. The frequency of lymph node metastases among patients fulfilling standard and expanded Japanese criteria for ER were 0 and 7.5%, respectively. CONCLUSIONS: The frequency of lymph node metastases among patients with early gastric cancer in a US population is higher than that of published Asian series. However, early gastric cancer lesions that meet the Japanese standard criteria for ER are associated with negligible risk of metastasis to lymph nodes, so ER can be recommended for definitive therapy. Expanded criteria cancers appear to have a higher risk of metastasis to lymph nodes, so ER may be considered for select cases.

Competence in Endoscopic Ultrasound and Endoscopic Retrograde Cholangiopancreatography, From Training Through Independent Practice.

BACKGROUND & AIMS: It is unclear whether participation in competency-based fellowship programs for endoscopic ultrasound (EUS) and endoscopic retrograde cholangiopancreatography (ERCP) results in high-quality care in independent practice. We measured quality indicator (QI) adherence during the first year of independent practice among physicians who completed endoscopic training with a systematic assessment of competence. METHODS: We performed a prospective multicenter cohort study of invited participants from 62 training programs. In phase 1, 24 advanced endoscopy trainees (AETs), from 20 programs, were assessed using a validated competence assessment tool. We used a comprehensive data collection and reporting system to create learning curves using cumulative sum analysis that were shared with AETs and trainers quarterly. In phase 2, participating AETs entered data into a database pertaining to every EUS and ERCP examination during their first year of independent practice, anchored by key QIs. RESULTS: By the end of training, most AETs had achieved overall technical competence (EUS 91.7%, ERCP 73.9%) and cognitive competence (EUS 91.7%, ERCP 94.1%). In phase 2 of the study, 22 AETs (91.6%) participated and completed a median of 136 EUS examinations per AET and 116 ERCP examinations per AET. Most AETs met the performance thresholds for QIs in EUS (including 94.4% diagnostic rate of adequate samples and 83.8% diagnostic yield of malignancy in pancreatic masses) and ERCP (94.9% overall cannulation rate). CONCLUSIONS: In this prospective multicenter study, we found that although competence cannot be confirmed for all AETs at the end of training, most meet QI thresholds for EUS and ERCP at the end of their first year of independent practice. This finding affirms the effectiveness of training programs. Clinicaltrials.gov ID NCT02509416.

Comparison of flexible endoscopic cricopharyngeal myectomy and myotomy approaches for Zenker diverticulum repair.

BACKGROUND AND AIMS: Incision of the cricopharyngeal (CP) muscle with flexible endoscopy is an important approach for Zenker diverticulum (ZD) repair with symptomatic resolution in approximately 90% of cases, but recurrence has been reported in up to 20%. We report our experience with a new endoscopic myectomy of the CP muscle and compare the outcome with conventional myotomy of ZD. METHODS: Our retrospective study included all patients with ZD who underwent endoscopic repair between August 1, 2014 and July 31, 2017. Conventional CP myotomy was defined as a vertical cut through the CP muscle. CP myectomy was defined as parallel excisions followed by snare resection at the CP resection base. Measurement of ZD size was based on barium esophagram and endoscopic estimation. Outcomes included ZD recurrence, improvement of dysphagia, and procedure adverse events. RESULTS: Sixty-four patients underwent endoscopic repair for ZD, 44 with CP myotomy and 20 with CP myectomy. Mean (standard deviation) size of ZD was 3.3 cm (1.0) and 3.8 cm (1.2) in the myotomy and myectomy cohorts, respectively (P = .11), and median procedure time was 50 and 56 minutes, respectively (P = .73). In the CP myotomy cohort, 10 patients (22.7%) had recurrence of ZD at a median of 19.1 months, whereas no recurrence was documented in the CP myectomy cohort (P = .02). This trend was also shown in multivariate analysis but was not statistically significant (P = .07). There was no statistical difference in improvement of dysphagia and adverse events. CONCLUSIONS: CP myectomy is a new endoscopic technique for ZD repair. In our experience, it was safe and well tolerated, with a high initial success rate and less ZD recurrence when compared with myotomy.

Setting minimum standards for training in EUS and ERCP: results from a prospective multicenter study evaluating learning curves and competence among advanced endoscopy trainees.

BACKGROUND AND AIMS: Minimum EUS and ERCP volumes that should be offered per trainee in "high quality" advanced endoscopy training programs (AETPs) are not established. We aimed to define the number of procedures required by an "average" advanced endoscopy trainee (AET) to achieve competence in technical and cognitive EUS and ERCP tasks to help structure AETPs. METHODS: American Society for Gastrointestinal Endoscopy (ASGE)-recognized AETPs were invited to participate; AETs were graded on every fifth EUS and ERCP examination using a validated tool. Grading for each skill was done using a 4-point scoring system, and learning curves using cumulative sum analysis for overall, technical, and cognitive components of EUS and ERCP were shared with AETs and trainers quarterly. Generalized linear mixed-effects models with a random intercept for each AET were used to generate aggregate learning curves, allowing us to use data from all AETs to estimate the average learning experience for trainees. RESULTS: Among 62 invited AETPs, 37 AETs from 32 AETPs participated. Most AETs reported hands-on EUS (52%, median 20 cases) and ERCP (68%, median 50 cases) experience before starting an AETP. The median number of EUS and ERCPs performed per AET was 400 (range, 200-750) and 361 (range, 250-650), respectively. Overall, 2616 examinations were graded (EUS, 1277; ERCP-biliary, 1143; pancreatic, 196). Most graded EUS examinations were performed for pancreatobiliary indications (69.9%) and ERCP examinations for ASGE biliary grade of difficulty 1 (72.1%). The average AET achieved competence in core EUS and ERCP skills at approximately 225 and 250 cases, respectively. However, overall technical competence was achieved for grade 2 ERCP at about 300 cases. CONCLUSION: The thresholds provided for an average AET to achieve competence in EUS and ERCP may be used by the ASGE and AETPs in establishing the minimal standards for case volume exposure for AETs during their training. (Clinical trial registration number: NCT02509416.).

Selective application of fully covered biliary stents and narrow-diameter esophageal stents for proximal esophageal indications.

BACKGROUND: Proximal esophageal stents are poorly tolerated and have a high risk of complications. We report our experience using fully covered, biliary, self-expandable metal stents (B-SEMS) and narrow-diameter, esophageal, self-expandable metal stents (NDE-SEMS) for this group of patients. METHODS: 24 patients underwent placement of B-SEMS or NDE-SEMS for proximal esophageal lesions between 1 January 2011 and 31 July 2016. The outcomes included improvement of dysphagia, healing of fistulas, and adverse events. RESULTS: 10 patients received B-SEMS and 14 had NDE-SEMS. Median follow-up time was 11.5 months (range 0.5 - 62 months). In both cohorts, stents were left in place for a mean of 6 weeks. The dysphagia score decreased in 7 (70 %) and 10 (71.4 %) patients, and fistulas resolved in 3/5 (60.0 %) and 5/8 (62.5 %) patients with B-SEMS and NDE-SEMS, respectively. Stent migration occurred in three patients (30.0 %) with B-SEMS and five patients (35.7 %) with NDE-SEMS. CONCLUSIONS: Both stents were well tolerated and resulted in overall improvement of dysphagia in 70.8 % of patients. B-SEMS appeared to be more favorable for cervical esophageal lesions with narrower diameters, while NDE-SEMS may be better for more distal lesions.

Subsquamous intestinal metaplasia is common in treatment-naïve Barrett's esophagus.

BACKGROUND AND AIMS: Barrett's intestinal metaplasia may extend beneath normal squamous epithelium at the squamocolumnar junction (SCJ) and therefore escape surveillance biopsy sampling. The prevalence of subsquamous intestinal metaplasia (SSIM) in patients undergoing Barrett's esophagus (BE) surveillance is unknown. Our aim was to examine the prevalence and distribution of SSIM proximal to the SCJ in patients undergoing BE surveillance. METHODS: We enrolled consecutive patients with biopsy specimen-proven BE. Biopsy specimens were obtained from the squamous epithelium at 5 mm and 10 mm above the SCJ. The primary outcomes were the proportion of patients with SSIM at each level. We further assessed factors associated with SSIM. RESULTS: We examined 515 squamous epithelial biopsy specimens from 106 BE patients (95% men; mean age, 66 years) with a mean Barrett's length of 3.0 cm. SSIM was present in 39% at 5 mm (95% CI, 29.4-48.6) and 21% (95% CI, 11.7-32.1) at 10 mm proximal to the SCJ. Among all biopsy specimens, 13% (95% CI, 10.6-16.6) contained SSIM: 17% (95% CI, 13-21.6) of biopsy samples at 5 mm and 8% (95% CI, 4.3-12.2) at 10 mm proximal to the SCJ. SSIM was more common in the anterior/right lateral position compared with the posterior/left lateral position (21% vs 11%, P = .001). None of the biopsy specimens showed dysplasia. Length of BE or duration of reflux symptoms were not associated with the presence of SSIM. CONCLUSIONS: This cross-sectional study found a surprisingly high proportion of SSIM in treatment-naïve patients proximal to the SCJ. These findings raise questions regarding BE management and the prevalence of SSIM in normal-appearing esophagus.

Resection outcomes and recurrence rates of endoscopic submucosal dissection (ESD) and hybrid ESD for colorectal tumors in a single Italian center.

BACKGROUND: Endoscopic submucosal dissection (ESD) and hybrid-ESD techniques are treatment modalities for colorectal neoplasia, although mostly used in the Eastern hemisphere. Only few data on ESD for colorectal neoplasia have been published in the West. We report the outcomes of colorectal ESD and hybrid ESD in a single Italian center. METHODS: We retrospectively evaluated the outcomes of all ESD and hybrid-ESD procedures for colorectal neoplasia performed over the first 2-year experience from a prospectively recorded database. Neuroendocrine tumors and adenocarcinoma with submucosal infiltration through the submucosal (SM) 2 layer or deeper were excluded. The primary outcome was the recurrence rate at the 6- to 12-month follow-up. RESULTS: Fifty-two patients were included in the study, of which 23 underwent ESD and 29 hybrid ESD. The mean lesion sizes for ESD and hybrid ESD were similar (25.8 vs. 25.4 mm, p = 0.940), while median procedure length was significantly longer for ESD (120 vs. 60 min, p < 0.001). ESD and hybrid ESD yielded similar en-bloc resection rate (82.6 vs. 82.8%) and R0 resection rate (34.8 vs. 31%). ESD had a lower neoplasia recurrence rate than hybrid ESD (11.7 vs. 20%) and a lower bleeding rate (0 vs. 8.7%). One perforation occurred in the hybrid-ESD cohort and two perforations in the ESD cohort, of which one required surgical intervention. Non-recurrence at follow-up was associated with R0 status, en-bloc resection, and lesion size ≤ 20 mm. CONCLUSION: Our outcomes are comparable with other studies in Western series. Studies addressing the cost effectiveness of ESD and comparing its long-term outcome with endoscopic mucosal resection in the West are needed.

Is There an Effect of Cannabis Consumption on Acute Pancreatitis?

BACKGROUND AND AIM: Twenty-percentage of acute pancreatitis (AP) cases is labeled as idiopathic. Cannabis remains the most frequently used illicit drug in the world. The aim of this study was to identify the prevalence of cannabis use among all patients with a first episode of AP, particularly in those labeled as idiopathic etiology, and determine any effect on AP severity. METHODS: Retrospective cohort of all consecutive patients admitted with a first episode of AP at a large tertiary referral hospital from 01/2013 through 12/2014. AP was identified by ICD9 code, or lipase ≥ 3 times the upper limit of normal and abdominal pain consistent with AP. Cannabis users (CU) were identified via history or urine toxicology. RESULTS: Four hundred and sixty patients were included. 54% were men, with a mean age of 48 years (range 17-89 years). Forty-eight patients (10%) were identified as CU. After adjusting for admission SIRS, age, and gender, cannabis use was not found to be an independent risk factor for persistent SIRS, AKI, ARDS, pancreatic necrosis, mortality, ICU admission, length of stay, in-hospital infections, nor recurrent AP. Of note, AKI was least common among non-CU compared to CU (OR 0.4; p = 0.02; CI 0.2-0.9) and non-CU had a higher admission BISAP score (≥ 2) compared to CU (OR 2.5; p = 0.009; CI 1.2-4.9). CONCLUSION: This is the largest study to date examining cannabis use in AP. Cannabis use was found across almost all etiologies of AP with a prevalence of 10% (48 cases), and in 9% (9 cases) of so-called idiopathic AP cases in this cohort, which could account as an association for approximately 2% of all AP cases. Cannabis use did not independently impact AP severity or mortality.

Endoscopic and surgical management of nonampullary duodenal neoplasms.

BACKGROUND: Sporadic nonampullary duodenal neoplasms (SNADN) can have malignant potential for which endoscopic and surgical resections are offered. We report combined gastroenterologic and surgical experience for treatment of SNADN, including endoscopic mucosal resection (EMR) and pancreas-preserving partial duodenectomy (PPPD). METHODS: We retrospectively reviewed 121 consecutive patients, who underwent 30 PPPDs and 91 EMRs for mucosal and submucosal SNADN. Decision to undergo EMR or surgical resection was based on expert endoscopist and surgeon discretion including multidisciplinary tumor board review. Main outcomes were recurrence rate of neoplasia and adverse events requiring hospital admission or prolonged care. EMRs were performed with submucosal lifting followed by snare resection. PPPD included total duodenectomy, supra-ampullary PPPD for neoplasms proximal to the ampulla, and infra-ampullary PPPD for lesions distal to the ampulla. Follow-up data were available for 65% of EMR and 73% of surgical patients. RESULTS: Surgically resected neoplasia was larger with more advanced neoplasia and submucosal lesions. En bloc resection was achieved in all surgical resections and in 53% of EMRs. Post-EMR, mucosal and submucosal neoplasia recurred in 32 and 0%, respectively, including five neoplasms (26%) after an initial negative esophagogastroduodenoscopy. All recurrences were treated endoscopically. Complications occurred in 14 endoscopically and eight surgically treated patients, none requiring surgical intervention. CONCLUSIONS: Post-EMR patients had higher recurrence of mucosal neoplasia, whereas submucosal neoplasms, mainly carcinoid, did not recur. Polyp size and positive resection margin were not associated with neoplasia recurrence. Patients with SNADN could benefit from a multidisciplinary approach to stratify the optimal treatment based on local expertise.

Correction to: Endoscopic and surgical management of nonampullary duodenal neoplasms.

This article was updated to correct the author listing for Carlos Roberto Simons-Linares.

Role of EUS in patients with suspected Barrett's esophagus with high-grade dysplasia or early esophageal adenocarcinoma: impact on endoscopic therapy.

BACKGROUND AND AIMS: Endoscopic therapy is the standard treatment for high-grade dysplasia and some cases of T1a esophageal adenocarcinoma (EAC), but it is not appropriate for deeply invasive disease. Data on the value of EUS for patient selection for endoscopic or surgical resection are conflicting. We investigated the outcome of esophageal EUS for the staging and treatment selection of patients with treatment-naive, premalignant Barrett's esophagus (BE) and suspected superficial EAC. METHODS: We retrospectively reviewed consecutive patients who underwent EUS for staging of treatment-naive, suspected premalignant BE and superficial EAC from January 2006 to June 2014. All patients referred for endoscopic therapy routinely underwent EUS. Patients with esophageal masses, squamous cell cancers, previous neoadjuvant therapy, or unrelated pathologies were excluded. Each patient's final diagnosis was verified by EMR, esophagectomy, or forceps biopsy sampling. Test characteristics of EUS were calculated. RESULTS: Three hundred thirty-five patients (mean age, 68 years; 86% male) with BE, a Prague C mean of 2.8 cm, and a Prague M mean of 4.5 cm were staged (pT0, 78% [6% nondysplastic, 24% low-grade dysplasia, 42% high-grade dysplasia]; pT1a, 14%; pT1b, 7%; and pT2, 1%). Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for patient selection to endoscopic (T1aN0 or less) or surgical therapy with EUS TN staging were 50%, 93%, 40%, 95%, and 90%, respectively. Comparable rates were achieved for patients with nodular BE. Overstaging occurred in 7% of patients, and EUS selected 11% for incorrect treatment modalities compared with pathologic staging. CONCLUSIONS: This study confirms the limited value of EUS suggested in the latest American College of Gastroenterology guidelines for BE management.

Endoscopic Management of Pancreatic Cysts.

Management of pancreatic cystic lesions relies on patients' clinical presentation, imaging, and endoscopic ultrasound. Current research in basic science, radiology, and endoscopy is evolving and making progress in this condition which is relatively common in the general population. This review focuses on the recent endoscopic ultrasound approaches to the diagnosis of these pancreatic disorders.

Colonoscopy practice for veterans within and outside the Veterans Affairs setting: a matched cohort study.

BACKGROUND AND AIMS: To minimize delays for colonoscopy within Veterans Affairs (VA) facilities, veterans may receive care at non-VA facilities based on fee-for-service contracts, and more recently, through the Veterans Access, Choice, and Accountability Act. The impact of diverting care from VA to non-VA facilities on quality of colonoscopy practice is unknown. METHODS: We identified all veterans aged 50 to 85 years who received a fee-basis colonoscopy for colorectal cancer screening or surveillance at non-VA facilities in 2007 to 2010. These patients were matched for sex, age, and year of procedure to veterans who underwent colonoscopies at VA medical centers. The outcomes of interest were the adenoma detection rates (ADR) and compliance with surveillance guidelines. RESULTS: During the observation period, 409 veterans (mean age 64 years; 94% men) underwent a fee-basis colonoscopy at 30 nonacademic (54%) and 2 academic (46%) facilities. Compared with colonoscopies performed at VA facilities, fee-basis colonoscopy patients had lower ADRs (38% vs 52%; P < .001), lower mean number of adenomas per procedure (0.72 vs 1.41; P < .001), and lower number of advanced ADRs (13% vs 22%; P < .001). Colonoscopies done at non-VA facilities were associated with lower ADRs in multivariate regression analysis (odds ratio 0.64; 95% CI, 0.44-0.92), whereas colonoscopies done in nonacademic settings or by colonoscopists who were not gastroenterologists were not. Compliance with surveillance guidelines was lower for colonoscopies performed outside VA facilities (80% vs 87%; P = .03). CONCLUSIONS: In this regional study (Northern New England), compliance with colonoscopy surveillance guidelines was high in both VA and non-VA settings; however, lower ADRs raise concern that referring veterans outside the VA system may impact colonoscopy quality.