A randomized, double-blind trial of succinylated gelatin submucosal injection for endoscopic resection of large sessile polyps of the colon

Normal saline solution versus other viscous solutions for submucosal injection during endoscopic mucosal resection: a systematic review and meta-analysis

BACKGROUND AND AIMS

EMR is being increasingly practiced for the removal of large colorectal polyps. A variety of solutions such as normal saline solution (NS) and other viscous and hypertonic solutions (VS) have been used as submucosal injections for EMR. A systematic review and meta-analysis is presented comparing the efficacy and adverse events of EMR performed using NS versus VS.

METHODS

Two independent reviewers conducted a search of all databases for human, randomized controlled trials that compared NS with VS for EMR of colorectal polyps. Data on complete en bloc resection, presence of residual lesions, and adverse events were extracted using a standardized protocol. Pooled odds ratio (OR) estimates along with 95% confidence intervals (CI) were calculated using fixed effect or random effects models.

RESULTS

Five prospective, randomized controlled trials (504 patients) met the inclusion criteria. The mean polyp sizes were 20.84 mm with NS and 21.44 mm with VS. On pooled analysis, a significant increase in en bloc resection (OR, 1.91; 95% CI, 1.11-3.29; P = .02; I² = 0%) and decrease in residual lesions (OR, 0.54; 95% CI, 0.32-0.91; P = .02; I² = 0%) were noted in VS compared with NS. There was no significant difference in the rate of overall adverse events between the 2 groups.

CONCLUSIONS

Use of VS during EMR leads to higher rates of en bloc resection and lower rates of residual lesions compared with NS, without any significant difference in adverse events. Endoscopists could consider using VS for EMR of large colorectal polyps and NS for smaller polyps because there is no significant difference in the outcomes with lesions <2 cm.

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

BACKGROUND AND AIMS

EMR is the primary treatment of large laterally spreading lesions (LSLs) in the colon. Residual or recurrent adenoma (RRA) is a major limitation. We aimed to identify a robust method to stratify the risk of RRA.

METHODS

Prospective multicenter data on consecutive LSLs ≥20 mm removed by piecemeal EMR from 8 Australian tertiary-care centers were included (September 2008 until May 2016). A logistic regression model for endoscopically determined recurrence (EDR) was created on a randomly selected half of the cohort to yield the Sydney EMR recurrence tool (SERT), a 4-point score to stratify the incidence of RRA based on characteristics of the index EMR. SERT was validated on the remainder of the cohort.

RESULTS

Analysis was performed on 1178 lesions that underwent first surveillance colonoscopy (SC1) (median 4.9 months, interquartile range [IQR] 4.9-6.2). EDR was detected in 228 of 1178 (19.4%) patients. LSL size ≥40 mm (odds ratio [OR] 2.47; P < .001), bleeding during the procedure (OR 1.78; P = .024), and high-grade dysplasia (OR 1.72; P = .029) were identified as independent predictors of EDR and allocated scores of 2, 1, and 1, respectively to create SERT. Lesions with SERT scores of 0 (SERT = 0) had a negative predictive value of 91.3% for RRA at SC1, and SERT was shown to stratify RRA to specific follow-up intervals by using Kaplan Meier curves (log-rank P < .001).

CONCLUSIONS

Guidelines recommend SC1 within 6 months of EMR. SERT accurately stratifies the incidence of RRA after EMR. SERT = 0 lesions could safely undergo first surveillance at 18 months, whereas lesions with SERT scores between 1 and 4 (SERT 1-4) require surveillance at 6 and 18 months. (Clinical trial registration number: NCT01368289.).

Extended endoscopic mucosal resection does not reduce recurrence compared with standard endoscopic mucosal resection of large laterally spreading colorectal lesions

BACKGROUND AND AIMS

Effective interventions to prevent residual and/or recurrent adenoma (RRA) after EMR of large sessile and laterally spreading colorectal lesions (LSL) are yet to be determined. RRA may occur due to inconspicuous adenoma at the EMR margin. We aimed to determine the efficacy and safety of extended EMR (X-EMR) compared with standard EMR (S-EMR).

METHODS

A single-center post hoc analysis of LSL ≥20 mm referred for treatment was performed. S-EMR was the standard sequential inject and resect method including a 1-mm to 2-mm margin of normal mucosa around the lesion. With X-EMR, at least a 5-mm margin of normal mucosa was excised. Patient and lesion characteristics and procedural outcomes were recorded. The primary endpoint was RRA at first surveillance colonoscopy at 4 months.

RESULTS

Between January 2009 and May 2011, 471 lesions (mean size, 37.9 mm) in 424 patients were resected by S-EMR, and between January 2012 and December 2013, 448 lesions (mean size, 39.1 mm) in 396 patients were resected by X-EMR. Resection was successful in 92.3% and 92.6% of referred lesions in the S-EMR and X-EMR groups, respectively (P = .978). X-EMR was independently associated with a higher risk of intraprocedural bleeding (IPB) (odds ratio, 3.1; 95% confidence interval [CI], 2.0-5.0; P < .001) but not other adverse events. RRA was present in 39 of 333 patients (11.7%) and 30 of 296 patients (10.1%) in the S-EMR and X-EMR groups, respectively (P = .15). X-EMR was not related to recurrence (hazard ratio, 0.8; 95% CI, 0.5-1.3; P = .399).

CONCLUSIONS

X-EMR does not reduce RRA and increases the risk of IPB compared with S-EMR. Alternative methods for the prevention of RRA are required.

Complications of endoscopic polypectomy, endoscopic mucosal resection and endoscopic submucosal dissection in the colon

Endoscopic resection (ER), including endoscopic polypectomy (EP), endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) are used to remove superficial neoplasms from the colon. Snare resection is used for EP and EMR, whereas endoscopic knives are used to perform dissection in the submucosal space in ESD. 80-90% colonic polyps are <10 millimetres (mm) and are effectively managed by conventional EP. Increasingly cold snare polypectomy is preferred. Large laterally spreading lesions (LSLs) and sessile polyps ≥20 mm are primarily removed by EMR. ESD may be used when superficial invasive disease is suspected and for some LSLs, particularly non-granular subtypes. Resection of colonic lesions by ER is associated with a small but definite incidence of significant complications, most commonly bleeding and perforation. This review discusses complications of ER with a particular focus on their prevention, early recognition and management. In many cases, complications from all three procedures share similar mechanisms and management principles and these are described at the start of each section, followed by a description of specific aspects for individual procedures.

Update on Difficult Polypectomy Techniques

Endoscopists often encounter colon polyps that are technically difficult to resect. These lesions traditionally were managed surgically, with significant potential morbidity and mortality. Recent advances in endoscopic techniques and instruments have allowed endoscopists to safely and effectively remove colorectal lesions with high technical and clinical success and potentially avoid invasive surgery. Endoscopic mucosal resection (EMR) has gained acceptance as the first-line therapy for large colorectal lesions. Endoscopic submucosal dissection (ESD) has been reported to be associated with higher rate of en bloc resection and less risk of short-time recurrence, but with an increased risk of adverse events. Therefore, the role of colorectal ESD should be restricted to lesions with high-risk morphologic features of submucosal invasion. In this article, we review the recent literature on the endoscopic management of difficult colorectal neoplasms.

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

OBJECTIVES

Clinically significant bleeding (CSPEB) is the most frequent adverse event following wide-field endoscopic mucosal resection (WF-EMR) of large sessile and laterally spreading colorectal lesions (LSL). There is limited knowledge regarding accurate prediction of CSPEB. We aimed to derive a score to predict the risk of CSPEB.

METHODS

Data on patient and lesion characteristics and outcomes from WF-EMRs of LSL ≥20 mm at 8 referral hospitals were analyzed. The cohort was divided at random into equal sized training and test groups. Independent predictors of CSPEB in the training cohort were identified by multiple logistic regression analysis and used to develop a risk score. The performance of this score was assessed in the independent test cohort.

RESULTS

Over 80 months to June 2015, 2,128 patients with 2,424 LSL were referred for WF-EMR. Two thousand and twelve patients were eligible for analysis. There were 135 cases of CSPEB (6.7%). In the training cohort of 1,006 patients, the independent predictors of CSPEB were lesion size >30 mm (odds ratio (OR) 2.5), proximal colonic location (OR 2.3), presence of a major comorbidity (OR 1.5), and epinephrine in injection solution (OR 0.57). The derived risk score comprised lesion size >30 mm (2 points), proximal colon (2 points), presence of major comorbidity (1 point), and absence of epinephrine use (1 point). The probabilities of CSPEB for scores of 0, 1, 2, 3, 4, and ≥5 in the training cohort were 1.5, 2.0, 5.6, 7.8, 9.1, and 17.5% and were 0.9, 6.7, 4.9, 6.2, 9.0, and 15.7% in the test cohort. The probabilities of CSPEB in those with low (score 0-1), medium (score 2-4), and elevated (score 5-6) risk levels were 1.7, 7.1, and 17.5% in the training cohort and 3.4, 6.2, and 15.7% in the test cohort.

CONCLUSIONS

Patients at elevated risk of CSPEB can be identified using four readily available variables. This knowledge may improve the management of those undergoing WF-EMR and assist in designing studies evaluating CSPEB.

Endoscopic mucosal resection and endoscopic submucosal dissection of large colonic polyps

Almost all large and complex colorectal polyps can now be resected endoscopically. Piecemeal endoscopic mucosal resection (PEMR) is an established technique with fairly low complication risk and good short-term and medium-term outcomes. Several modifications to the basic injection and snare technique have been developed contributing to safer and more complete resections. Delayed bleeding requiring reintervention is the most troublesome complication in 2-7% of patients, particularly in those with comorbidities and large, right-sided polyps. Endoscopic submucosal dissection (ESD) has become popular in Japan and has theoretical advantages over PEMR in providing a complete, en bloc excision for accurate histological staging and reduced local recurrence. These advantages come at the cost of a more complex, expensive and time-consuming procedure with a higher risk of perforation, particularly early in the procedure learning curve. These factors have contributed to the slow adoption of ESD in the West and the challenge to develop new devices and endoscopic platforms that will make ESD easier and safer. Currently, ESD indications are limited to large rectal lesions, in which procedural complications are easily managed, and for colorectal polyps with a high risk of containing tiny foci of early submucosally invasive cancer, whereby ESD may be curative compared with PEMR.

Endoscopic resection is cost-effective compared with laparoscopic resection in the management of complex colon polyps: an economic analysis

BACKGROUND AND AIMS

Endoscopic resection (ER) is an efficacious treatment for complex colon polyps (CCPs). Many patients are referred for surgical resection because of concerns over procedural safety, incomplete polyp resection, and adenoma recurrence after ER. Efficacy data for both resection strategies are widely available, but a paucity of data exist on the cost-effectiveness of each modality. The aim of this study was to perform an economic analysis comparing ER and laparoscopic resection (LR) strategies in patients with CCP.

METHODS

A decision analysis tree was constructed using decision analysis software. The 2 strategies (ER vs LR) were evaluated in a hypothetical cohort of patients with CCPs. A hybrid Markov model with a 10-year time horizon was used. Patients entered the model after colonoscopic diagnosis at age 50. Under Strategy I, patients underwent ER followed by surveillance colonoscopy at 3 to 6 months and 12 months. Patients with failed ER and residual adenoma at 12 months were referred for LR. Under Strategy II, patients underwent LR as primary treatment. Patients with invasive cancer were excluded. Estimates regarding ER performance characteristics were obtained from a systematic review of published literature. The Centers for Medicare & Medicaid Services (2012-2013) and the 2012 Healthcare Cost and Utilization Project databases were used to determine the costs and loss of utility. We assumed that all procedures were performed with anesthesia support, and patients with adverse events in both strategies required inpatient hospitalization. Baseline estimates and costs were varied by using a sensitivity analysis through the ranges.

RESULTS

LR was found to be more costly and yielded fewer quality-adjusted life-years (QALYs) compared with ER. The cost of ER of a CCP was $5570 per patient and yielded 9.640 QALYs. LR of a CCP cost $18,717 per patient and yielded fewer QALYs (9.577). For LR to be more cost-effective, the thresholds of 1-way sensitivity analyses were (1) technical success of ER for complete resection in <75.8% of cases, (2) adverse event rates for ER > 12%, and (3) LR cost of <$14,000.

CONCLUSIONS

Our data suggest that ER is a cost-effective strategy for removal of CCPs. The effectiveness is driven by high technical success and low adverse event rates associated with ER, in addition to the increased cost of LR.

Endoscopy in the Diagnosis and Management of Complications of Inflammatory Bowel Disease

The role of endoscopy in inflammatory bowel disease (IBD) has grown over the last decade in both diagnostic and therapeutic realms. It aids in the initial diagnosis of the disease and also in the assessment of the extent and severity of disease. IBD is associated with development of multiple complications such as strictures, fistulae, and colon cancers. Endoscopy plays a pivotal role in the diagnosis of colon cancer in patients with IBD through incorporation of chromoendoscopy for surveillance. In addition, endoscopic resection with surveillance is recommended in the management of polypoid dysplastic lesions without flat dysplasia. IBD-associated benign strictures with obstructive symptoms amenable to endoscopic intervention can be managed with endoscopic balloon dilation both in the colon and small intestine. In addition, endoscopy plays a major role in assessing the neoterminal ileum after surgery to risk-stratify patients after ileocolonic resection and assessment of a patient with ileoanal pouch anastomosis surgery and management of postsurgical complications. Our article summarizes the current evidence in the role of endoscopy in the diagnosis and management of complications of IBD.

Efficacy and safety of endoscopic resection of large colorectal polyps: a systematic review and meta-analysis

OBJECTIVE

To assess the efficacy and safety of endoscopic resection of large colorectal polyps.

DESIGN

Relevant publications were identified in MEDLINE/EMBASE/Cochrane Central Register for the period 1966-2014. Studies in which ≥20 mm colorectal neoplastic lesions were treated with endoscopic resection were included. Rates of postendoscopic resection surgery due to non-curative resection or adverse events, as well as the rates of complete endoscopic removal, invasive cancer, adverse events, recurrence and mortality, were extracted. Study quality was ascertained according to Newcastle-Ottawa Scale. Forest plot was produced based on random effect models. I2 statistic was used to describe the variation across studies due to heterogeneity. Meta-regression analysis was also performed.

RESULTS

50 studies including 6442 patients and 6779 large polyps were included in the analyses. Overall, 503 out of 6442 patients (pooled rate: 8%, 95% CI 7% to 10%, I2=78.6%) underwent surgery due to non-curative endoscopic resection, and 31/6442 (pooled rate: 1%, 95% CI 0.7% to 1.4%, I2=0%) to adverse events. Invasive cancer at histology, non-curative endoscopic resection, synchronous lesions and recurrence accounted for 58%, 28%, 2.2% and 5.9% of all the surgeries, respectively. Endoscopic perforation occurred in 96/6595 (1.5%, 95% CI 1.2% to 1.7%) polyps, while bleeding in 423/6474 (6.5%, 95% CI 5.9% to 7.1%). Overall, 5334 patients entered in surveillance, 502/5836 (8.6%, 95% CI 7.9% to 9.3%) being lost at follow-up. Endoscopic recurrence was detected in 735/5334 patients (13.8%, 95% CI 12.9% to 14.7%), being an invasive cancer in 14/5334 (0.3%, 95% CI 0.1% to 0.4%). Endoscopic treatment was successful in 664/735 cases (90.3%, 95% CI 88.2% to 92.5%). Mortality related with management of large polyps was reported in 5/6278 cases (0.08%, 95% CI 0.01% to 0.15%).

CONCLUSIONS

Endoscopic resection of large polyps appeared to be an extremely effective and safe intervention. However, an adequate endoscopic surveillance is necessary for its long-term efficacy.

Endoscopic resection of colorectal lesions: The narrowing divide between East and West

Colonic polypectomy is an effective way of reducing colon cancer mortality. Multiple techniques now exist for the resection of polyps, and the endoscopist must decide on the appropriate resection approach for individual patients and lesions. This decision should maximize efficacy, safety and cost-effectiveness and provide optimal oncological outcomes while minimizing unnecessary surgical treatment. Advances in endoscopic imaging technology are improving the accuracy of endoscopic diagnosis and allowing more precise risk assessment of colonic lesions. Resection technique can be tailored to the endoscopic findings. Diminutive (≤5 mm) and small polyps (≤9 mm) are best resected primarily by snare techniques. Cold snare polypectomy has proven safety, but efficacy and technique require further study. There is variation in techniques used for polyps 6-20 mm in size and incomplete resection rates for conventional polypectomy may be considerable. Endoscopic mucosal resection (EMR) is well established, safe and effective for lesions without submucosal invasion (SMI); however, recurrence is a key limitation. Endoscopic submucosal dissection (ESD) is well established in the East; however, it is resource intensive and its role in lesions with a low risk of SMI is questionable. ESD in the West remains incompletely defined and is associated with high adverse event rates, but it is becoming increasingly available and successful as experience grows. Emerging full-thickness resection technologies are still in their infancy and remain experimental as a result of the absence of reliable closure devices and techniques. Patient-focused outcomes should guide technique selection.

Solutions for submucosal injection in endoscopic resection: a systematic review and meta-analysis

BACKGROUND AND AIMS

Submucosal injection is standard practice in endoscopic mucosal resection of gastrointestinal lesions. Several solutions are used. Our aim was to systematically review their efficacy and safety.

PATIENTS AND METHODS

We performed a systematic review and meta-analysis using a random effects model of randomized controlled trials (RCTs) from MEDLINE. Studies in animal models were qualitatively assessed for efficacy and safety.

RESULTS

In total, 54 studies were qualitatively assessed. Eleven RCTs were analyzed, two of which were on endoscopic submucosal dissection (ESD). The quantitative synthesis included nine RCTs on endoscopic mucosal resection (EMR), comprising 792 subjects and 793 lesions. Mean lesion size was 20.9 mm (range 8.5 - 46 mm). A total of 209 lesions were randomized to sodium hyaluronate (SH) vs normal saline (NS), 72 to 50 % dextrose (D50) vs NS, 82 to D50 vs SH, 43 to succinylated gelatin, 25 to hydroxyethyl starch and 36 to fibrinogen. In total, 385 were randomized to NS as controls. NS and SH are the best studied solutions and seem to be equally effective in achieving complete resection (OR 1.09; 95 %CI 0.82, 1.45). No solution was proven to be superior in complete resection rate, post-polypectomy bleeding or coagulation syndrome/perforation incidence. Many solutions have been tested in animal studies and most seem more effective for mucosal elevation than NS.

CONCLUSIONS

There are several solutions in clinical use and many more under research, but most are poorly studied. SH seems to be clinically equivalent to NS. There are no significant differences in post-polypectomy complications. Larger RCTs are needed to determine any small differences that may exist between solutions.

British Society of Gastroenterology/Association of Coloproctologists of Great Britain and Ireland guidelines for the management of large non-pedunculated colorectal polyps

These guidelines provide an evidence-based framework for the management of patients with large non-pedunculated colorectal polyps (LNPCPs), in addition to identifying key performance indicators (KPIs) that permit the audit of quality outcomes. These are areas not previously covered by British Society of Gastroenterology (BSG) Guidelines.A National Institute of Health and Care Excellence (NICE) compliant BSG guideline development process was used throughout and the Appraisal of Guidelines for Research and Evaluation (AGREE II) tool was used to structure the guideline development process. A systematic review of literature was conducted for English language articles up to May 2014 concerning the assessment and management of LNPCPs. Quality of evaluated studies was assessed using the Scottish Intercollegiate Guidelines Network (SIGN) Methodology Checklist System. Proposed recommendation statements were evaluated by each member of the Guideline Development Group (GDG) on a scale from 1 (strongly agree) to 5 (strongly disagree) with >80% agreement required for consensus to be reached. Where consensus was not reached a modified Delphi process was used to re-evaluate and modify proposed statements until consensus was reached or the statement discarded. A round table meeting was subsequently held to finalise recommendations and to evaluate the strength of evidence discussed. The GRADE tool was used to assess the strength of evidence and strength of recommendation for finalised statements.KPIs, a training framework and potential research questions for the management of LNPCPs were also developed. It is hoped that these guidelines will improve the assessment and management of LNPCPs.

Polidocanol injection decreases the bleeding rate after colon polypectomy: a propensity score analysis

BACKGROUND

EMR is the standard of care for the resection of large polyps.

OBJECTIVE

To compare the efficacy and safety profile of submucosal polidocanol injection with epinephrine-saline solution injection for colon polypectomy with a diathermic snare.

DESIGN

After 1-to-1 propensity score caliper matching, comparison of submucosal epinephrine injection was performed with polidocanol injection.

SETTING

Endoscopic suite at the University of Foggia between 2005 and 2014.

PATIENTS

Of 711 patients who underwent endoscopic resection of colon sessile polyps 20 mm or larger, 612 were analyzed after matching.

INTERVENTIONS

Submucosal epinephrine injection in 306 patients and polidocanol injection in 306 patients.

MAIN OUTCOME MEASUREMENTS

Univariate and multivariate logistic regression models aimed at identifying independent predictors of postpolypectomy bleeding (PPB).

RESULTS

The 2 groups presented similar baseline clinical parameters and lesion characteristics. All patients had a single polyp 20 mm or larger; the median size was 32 mm (interquartile range [IQR], 25-38) in the polidocanol group and 32 (IQR, 24-38) in the epinephrine group (P=.7). Polidocanol was more effective in preventing both immediate and delayed PPB (P<.001 and P=.003, respectively), and its efficacy was confirmed in almost all of the subgroups, regardless of polyp size and histology. Postprocedure perforation was observed in 2 patients (0.3%), both in the epinephrine group (P=.49). The 2 groups did not differ in the number of snare resections of lesions or the procedure duration (P=.24 and .6, respectively).

LIMITATIONS

Absence of randomization.

CONCLUSION

The submucosal injection of polidocanol for colon EMR is effective and significantly lowers the PPB rate.

Endoscopic mucosal resection

EMR has become an established therapeutic option for premalignant and early-stage GI malignancies, particularly in the esophagus and colon. EMR can also aid in the diagnosis and therapy of subepithelial lesions localized to the muscularis mucosa or submucosa. Several dedicated EMR devices are available to facilitate these procedures. Adverse event rates, particularly bleeding and perforation, are higher after EMR relative to other basic endoscopic interventions but lower than adverse event rates for ESD. Endoscopists performing EMR should be knowledgeable and skilled in managing potential adverse events resulting from EMR.

Non-polypoid colorectal neoplasms: Classification, therapy and follow-up

In the last years, an increasing interest has been raised on non-polypoid colorectal tumors (NPT) and in particular on large flat neoplastic lesions beyond 10 mm tending to grow laterally, called laterally spreading tumors (LST). LSTs and large sessile polyps have a greater frequency of high-grade dysplasia and local invasiveness as compared to pedunculated lesions of the same size and usually represent a technical challenge for the endoscopist in terms of either diagnosis and resection. According to the Paris classification, NPTs are distinguished in slightly elevated (0-IIa, less than 2.5 mm), flat (0-IIb) or slightly depressed (0-IIc). NPTs are usually flat or slightly elevated and tend to spread laterally while in case of depressed lesions, cell proliferation growth progresses in depth in the colonic wall, thus leading to an increased risk of submucosal invasion (SMI) even for smaller neoplasms. NPTs may be frequently missed by inexperienced endoscopists, thus a careful training and precise assessment of all suspected mucosal areas should be performed. Chromoendoscopy or, if possible, narrow-band imaging technique should be considered for the estimation of SMI risk of NPTs, and the characterization of pit pattern and vascular pattern may be useful to predict the risk of SMI and, therefore, to guide the therapeutic decision. Lesions suitable to endoscopic resection are those confined to the mucosa (or superficial layer of submucosa in selected cases) whereas deeper invasion makes endoscopic therapy infeasible. Endoscopic mucosal resection (EMR, piecemeal for LSTs > 20 mm, en bloc for smaller neoplasms) remains the first-line therapy for NPTs, whereas endoscopic submucosal dissection in high-volume centers or surgery should be considered for large LSTs for which en bloc resection is mandatory and cannot be achieved by means of EMR. After piecemeal EMR, follow-up colonoscopy should be performed at 3 mo to assess resection completeness. In case of en bloc resection, surveillance colonoscopy should be scheduled at 3 years for adenomatous lesions ≥ 1 cm, or in presence of villous features or high-grade dysplasia patients (regardless of the size), while less intensive surveillance (colonoscopy at 5-10 years) is needed in case of single (or two) NPT < 1 cm presenting tubular features or low-grade dysplasia at histology.

Advanced polypectomy and resection techniques

Most colorectal cancer arises from adenomatous polyps. This gradual process may be interrupted by screening and treatment using colonoscopy and polypectomy. Advances in imaging platforms have led to classification systems that facilitate prediction of histologic type and both stratification for and prediction of the risk of invasion. Endoscopic treatment should be the standard of care even for extensive advanced mucosal neoplasm. Technique selection is influenced by lesion features, location, patient factors, and local expertise. Postprocedural complications are more common following advanced resection and endoscopists should be familiar with risk factors, early detection methods, and management.

Prophylactic endoscopic coagulation to prevent bleeding after wide-field endoscopic mucosal resection of large sessile colon polyps

BACKGROUND & AIMS

Clinically significant postendoscopic mucosal resection bleeding (CSPEB) is the most frequent significant complication of wide-field endoscopic mucosal resection (WF-EMR) of advanced mucosal neoplasia (sessile or laterally spreading colorectal lesions > 20 mm). CSPEB requires resource-intensive management and there is no strategy for preventing it. We investigated whether prophylactic endoscopic coagulation (PEC) reduces the incidence of CSPEB.

METHODS

We performed a prospective randomized controlled trial of 347 patients (mean age, 67.1 y; 55.3% with proximal colonic lesions) undergoing WF-EMR for advanced mucosal neoplasia at 3 Australian tertiary referral centers. Patients were assigned randomly (1:1) to groups receiving PEC (n = 172) or no additional therapy (n = 175, controls). PEC was performed with coagulating forceps, applying low-power coagulation to nonbleeding vessels in the resection defect. CSPEB was defined as bleeding requiring admission to the hospital. The primary end point was the proportion of CSPEB.

RESULTS

Patients in each group were similar at baseline. CSPEB occurred in 9 patients receiving PEC (5.2%) and 14 controls (8.0%; P = .30). CSPEB was associated significantly with proximal colonic location on multivariate analysis (odds ratio, 3.08; P = .03). Compared with the proximal colon, there was a significantly greater number (3.8 vs 2.1; P = .002) and mean size (0.5-1 vs 0.3-0.5 mm; P = .04) of visible vessels in the distal colon.

CONCLUSIONS

PEC does not significantly decrease the incidence of CSPEB after WF-EMR. There were significantly more and larger vessels in the WF-EMR mucosal defect of distal colonic lesions, yet CSPEB was more frequent with proximal colonic lesions. ClinicalTrials.gov NCT01368731.

Improving complete EMR of colorectal neoplasia: a randomized trial comparing snares and injectate in the resection of large sessile colon polyps

BACKGROUND

There are few randomized studies examining efficacy of snares and agents in EMR.

OBJECTIVE

To compare the use of a combined needle and snare unit with injectate versus a spiral wire and injectate (primary); saline solution versus hydroxypropyl methylcellulose (secondary).

DESIGN

Prospective, randomized, factorial, single center.

SETTING

Tertiary-care academic medical center.

PATIENTS

A total of 140 patients with large (>15 mm), sessile, colorectal polyps.

INTERVENTIONS

Polyps randomized to either 1 of 2 snare types and 1 of 2 injectates.

MAIN OUTCOME MEASUREMENTS

Primary-the Sydney resection quotient (SRQ), defined as the size of the polyp divided by the number of pieces resected and the amount of tissue per snare attempt. Secondary-procedure time, adverse events, residual neoplasia at follow-up.

RESULTS

The SRQ was higher with the combined unit (median 13.8 mm vs 7.1 mm; P = .019); additionally, procedure time was less (median 6 vs 11 minutes; P < .001). Resection was considered complete after the EMR in 62% (42/68) with the combined needle and snare unit versus 51% (37/72; P = .22) with the spiral wire. Rates of adverse events were similar. Residual neoplasia was found at follow-up in 22% (10/46) with the combined needle and snare unit versus 21% (10/48; P = .89) with the spiral wire. There was no evidence of differences in outcomes by lifting agent.

LIMITATIONS

The SRQ is only a surrogate marker.

CONCLUSION

This study provides evidence that the integrated needle-snare may be superior to the snare alone for the removal of large, flat polyps. Additionally, the type of injectate appears to have no impact on outcome.

Submucosal injection solution for endoscopic resection in gastrointestinal tract: a traditional and network meta-analysis

Objective. To explore and define the current optimal submucosal injection solution used in ESD and EMR for gastrointestinal tract neoplasms in terms of clinical outcomes and other aspects. Methods. PubMed, Cochrane Library, Embase, and clinical trials register center were searched with terms of “endoscopic resection” and “submucosal injection solution” to identify relevant randomized controlled trials (RCTs). Both direct comparison using traditional meta-analysis method and indirect comparison using network meta-analysis method were performed. Results. A total of 11 RCTs with 1152 patients were included. Meta-analysis showed that, compared with normal saline, other submucosal injection solutions induced a significant increase in terms of en bloc resection rate (I² = 0%, OR = 2.11, 95% CI (1.36, 3.26), and P = 0.008) and complete resection rate (I² = 0%, OR = 2.14, 95% CI (1.41, 3.24), and P = 0.0003); and there was no significant difference in the incidence of total complications (I² = 0%, OR = 0.87, 95% CI (0.59, 1.29), and P = 0.49). Conclusions. Other newly developed submucosal injection solutions significantly increased en bloc resection rate and complete resection rate and decreased bleeding rate and finical cost of endoscopic resection in gastrointestinal tract, while current evidence did not find the difference between them, which need to be explored by further studies.

Adverse events related to colonic endoscopic mucosal resection and polypectomy

Colonoscopy is a commonly performed procedure. The rate of adverse events is 2.8 per 1000 screening colonoscopies. These adverse events include cardiovascular and pulmonary events, abdominal pain, hemorrhage, perforation, postpolypectomy syndrome, infection, and death. Serious adverse events, such as hemorrhage and perforation, occur most frequently when colonoscopy is performed with polypectomy. This article highlights the prevention and management of adverse events associated with polypectomy and endoscopic mucosal resection of colonic lesions.

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

OBJECTIVE

Wide-field endoscopic mucosal resection (WF-EMR) is an alternative to surgery for treatment of advanced colonic mucosal neoplasia up to 120 mm in size, but has been criticised for its potentially high recurrence rates. We aimed to quantify recurrence at 4 months (early) and 16 months (late) following successful WF-EMR and identify its risk factors and clinical significance.

DESIGN

Ongoing multicentre, prospective, intention-to-treat analysis of sessile or laterally spreading colonic lesions ≥20 mm in size referred for WF-EMR to seven academic endoscopy units. Surveillance colonoscopy (SC) was performed 4 months (SC1) and 16 months (SC2) after WF-EMR, with photographic documentation and biopsy of the scar.

RESULTS

1134 consecutive patients were enrolled when 1000 successful EMRs were achieved, of whom 799 have undergone SC1. 670 were normal. Early recurrent/residual adenoma was present in 128 (16.0%, 95% CI 13.6% to 18.7%). One case was unknown. The recurrent/residual adenoma was diminutive in 71.7% of cases. On multivariable analysis, risk factors were lesion size >40 mm, use of argon plasma coagulation and intraprocedural bleeding. Of 670 with normal SC1, 426 have undergone SC2, with late recurrence present in 17 cases (4.0%, 95% CI 2.4% to 6.2%). Overall, recurrent/residual adenoma was successfully treated endoscopically in 135 of 145 cases (93.1%, 95% CI 88.1% to 96.4%). If the initial EMR was deemed successful and did not contain submucosal invasion requiring surgery, 98.1% (95% CI 96.6% to 99.0%) were adenoma-free and had avoided surgery at 16 months following EMR.

CONCLUSIONS

Following colonic WF-EMR, early recurrent/residual adenoma occurs in 16%, and is usually unifocal and diminutive. Risk factors were identified. Late recurrence occurs in 4%. Overall, recurrence was managed endoscopically in 93% of cases. Recurrence is not a significant clinical problem following WF-EMR, as with strict colonoscopic surveillance, it can be managed endoscopically with high success rates.

TRIAL REGISTRATION NUMBER

NCT01368289.

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

BACKGROUND & AIMS

Bleeding is the main complication of wide-field endoscopic mucosal resection (WF-EMR) for large colonic lesions. Few studies have examined bleeding outcomes after WF-EMR, and there are no evidence-based guidelines for management of bleeding in this group. We analyzed outcomes of patients with clinically significant post-EMR bleeding (CSPEB) and present a management algorithm based on our findings.

METHODS

In a prospective study, we collected data from WF-EMR of sessile colorectal polyps 20 mm or larger from 1039 patients who participated in the Australian Colonic Endoscopic resection multicenter study from July 2008 through May 2012. Data included patient and lesion characteristics and procedural, clinical, and histologic outcomes. Patients participated in a structured telephone interview 14 days after the procedure; independent predictors of a moderate or severe outcome by American Society of Gastrointestinal Endoscopists criteria, or any intervention for hemostasis, were identified.

RESULTS

Sixty-two patients had CSPEB (6.0%); 34 were managed conservatively (55%) and 27 underwent colonoscopy (44%). One patient had primary embolization. Endoscopic therapy was applied in 21 cases; 14 had active bleeding. Two of the conservatively managed cases underwent colonoscopy for rebleeding after discharge. On multivariable analysis, moderate or severe bleeding events were associated with hemodynamic instability (odds ratio, 12.3; P = .046) and low level of hemoglobin at presentation (odds ratio, 0.50 per 1.0 g/dL; P = .005). Intervention for hemostasis was associated with hourly or more frequent hematochezia (odds ratio, 36.7; P = .001), American Society of Anesthesiologists grade 2 or higher (odds ratio, 20.1; P < .001), and transfusion (odds ratio, 18.7; P = .003).

CONCLUSIONS

Based on a multicenter prospective study, CSPEB resolves spontaneously in 55% of patients. We developed a risk factor-based algorithm that might assist physicians in the management of bleeding. Patients responding to initial resuscitation can be observed, with a lower threshold for intervention in those with the identified risk factors.

Endoscopic mucosal resection and endoscopic submucosal dissection of epithelial neoplasia of the colon

Endoscopic mucosal resection (EMR) with curative intent has evolved into a safe and effective technique and is currently the gold standard for management of large colonic epithelial neoplasms. Piecemeal EMR is associated with a high risk of local recurrence requiring vigilant surveillance and repeat interventions. Endoscopic submucosal dissection (ESD) was introduced in Japan for the management of early gastric cancer, and has recently been described for en bloc resection of colonic lesions greater than 20 mm. En bloc resection allows accurate histological assessment of the depth of invasion, minimizes the risk of local recurrence and helps determine additional therapy. Morphologic classification of lesions prior to resection allows prediction of depth of invasion and risk of nodal metastasis, allowing selection of the appropriate intervention. This review provides an overview of the assessment of epithelial neoplasms of the colon and the application of EMR and ESD techniques in their management.

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

BACKGROUND & AIMS

Wide-field endoscopic mucosal resection (WF-EMR) of large sessile colonic polyps is a safe and cost-effective outpatient treatment. Bleeding is the main complication. Few studies have examined risk factors for bleeding during the procedure (intraprocedural bleeding [IPB]) or after it (clinically significant post-endoscopic bleeding [CSPEB]). We investigated factors associated with IPB and CSPEB in a large prospective study.

METHODS

We analyzed data from WF-EMRs of sessile colorectal polyps ≥ 20 mm in size (mean size, 35.5 mm), which were performed on 1172 patients (mean age, 67.8 years) from June 2008-March 2013 at 7 tertiary hospitals as part of the Australian Colonic Endoscopic Resection Study. Data were collected on characteristics of patients and lesions, along with outcomes of procedures and clinical and histologic analyses. Independent predictors of IPB and CSPEB were identified by multiple logistic regression analysis.

RESULTS

Of the patients studied, 133 (11.3%) had IPB. Independent predictors included increasing lesion size (odds ratio, 1.24/10 mm; P < .001), Paris endoscopic classification of 0-IIa + Is (odds ratio, 2.12; P = .004), tubulovillous or villous histology (odds ratio, 1.84; P = .007), and study institutions that performed the procedure on fewer than 75 patients (odds ratio, 3.78; P < .001). All IPB was successfully controlled endoscopically. IPB prolonged procedures and was associated with early recurrence (relative risk, 1.68; P = .011). Seventy-three patients (6.2%) had CSPEB. On multivariable analysis, CSPEB was associated with proximal colon location (odds ratio, 3.72; P < .001), use of an electrosurgical current not controlled by a microprocessor (odds ratio, 2.03; P = .038), and IPB (odds ratio, 2.16; P = .016). Lesion size and comorbidities did not predict CSPEB.

CONCLUSIONS

In a prospective study of patients undergoing WF-EMR of large sessile colonic polyps, IPB is associated with larger lesions, lesion histology, and Paris endoscopic classification of type 0-IIa + Is. IPB prolongs the duration of the procedure, is a marker for recurrence, and is associated with CSPEB. CSPEB occurs most frequently in the proximal colon and less when current is controlled by a microprocessor.

Advanced mucosal neoplasia of the anorectal junction: endoscopic resection technique and outcomes (with videos)

BACKGROUND

EMR at the anorectal junction (ARJ) is technically challenging. Issues of safety and procedural efficacy dictate that surgery is still performed as the primary management for noninvasive lesions in most centers. Modifications to the standard EMR technique may help to address the unique features and achieve safe and curative resection of most lesions.

OBJECTIVE

To describe an effective and safe, modified EMR technique to remove advanced mucosal neoplasia (AMN) of the ARJ.

DESIGN

Prospective, observational cohort study.

SETTING

Academic, tertiary care referral center.

PATIENTS

Patients undergoing EMR for AMN at the ARJ over 4.5 years, from June 2008 to December 2012.

INTERVENTIONS

Use of long-acting local anesthetic in the submucosal injectate, endoscopic resection over the dentate line and hemorrhoidal columns, prophylactic antibiotics for resection of lesions at high risk for bacteremia, and cap and gastroscope-assisted resection.

MAIN OUTCOME MEASUREMENTS

Procedural success and safety.

RESULTS

Twenty-six patients with lesions involving the ARJ were referred for EMR (males 53.8%, median age 63, median lesion size 40 mm). Two patients went directly to surgery because of an endoscopic diagnosis of adenocarcinoma. EMR was performed in 24 lesions with complete adenoma clearance achieved in 100%. Four patients were admitted to the hospital. Focal adenoma recurrence was seen in 4 of 18 patients (22%) at first surveillance colonoscopy and was managed by snare diathermy resection. No recurrences were found at the second follow-up colonoscopy. Procedural success, adenoma recurrence, and admission rates were similar between EMRs performed at the ARJ and proximal rectum on univariate analysis (all P > .05).

LIMITATIONS

Single tertiary center, nonrandomized study.

CONCLUSIONS

Simple modifications to the EMR technique allow safe and effective treatment of AMN at the ARJ on an outpatient basis and should be the first-line management when the risk of invasive disease is low.

Colonoscopic polypectomy: current techniques and controversies

Colonoscopic polypectomy is fundamental to effective colonoscopy. Through its impact on the polyp-cancer sequence, colonoscopic polypectomy reduces colorectal cancer incidence and mortality. Because it eliminates electrosurgical risk, cold snaring has emerged as the preferred technique for most small and all diminutive polyps. Few clinical trial data are available on the effectiveness and safety of specific techniques. Polypectomy technique seems highly variable between endoscopists, with some techniques more effective than others are. Further research is needed to investigate operator variation in polypectomy outcomes and establish an evidence base for best practice.

Snare tip soft coagulation achieves effective and safe endoscopic hemostasis during wide-field endoscopic resection of large colonic lesions (with videos)

BACKGROUND

Wide-field EMR (WF-EMR) of large colonic lesions exposes submucosal vessels, which may result in intraprocedural bleeding (IPB). Ongoing bleeding may obscure the endoscopic field, prolonging the procedure and reducing safety and accuracy. A number of potential interventions to control bleeding exist; however, they have inherent limitations. Safe, readily applicable, inexpensive, and effective therapy to control EMR-IPB has not yet been described.

OBJECTIVE

To evaluate the safety and efficacy of the snare tip soft coagulation (STSC) technique to control IPB after WF-EMR of large colonic lesions.

DESIGN

Single-center, prospective cohort study.

SETTING

Tertiary care referral center.

PATIENTS

A total of 196 patients undergoing wide-field colonic EMR for flat and sessile lesions 20 mm or larger.

INTERVENTIONS

A standard inject-and-resect EMR technique was applied. IPB was defined as bleeding obscuring the endoscopic field that persisted for 60 seconds or longer. STSC was performed by using the tip of the polypectomy snare to apply soft coagulation (80 W) to sites of IPB.

MAIN OUTCOME MEASUREMENTS

Immediate hemostasis, postprocedural bleeding, and other adverse events.

RESULTS

A total of 198 lesions (mean size 41.5 mm, 64% in the right colon) were removed in 196 patients (mean age 68 years, 52.5% male). STSC alone achieved effective hemostasis in 40 of 44 cases of IPB (91%). In the remaining 4 cases, additional treatment with coagulating forceps or clips was required to achieve hemostasis. There were no immediate STSC-related adverse events. There was no statistically significant difference between the IPB and non-IPB groups in relation to the use of antiplatelet (P = .2) or anticoagulation agents (P = .4), postprocedural bleeding (P = .8) and adverse event rates (P = .7).

LIMITATIONS

Nonrandomized study.

CONCLUSIONS

STSC is a simple and efficient first-line technique for achieving hemostasis of IPB during WF-EMR in the colon. It succeeds in the majority of cases and appears to be safe.

Creation of simulated papillae for endoscopic sphincterotomy and papillectomy training by using in vivo and ex vivo pig model (with videos)

BACKGROUND

There are few in vivo and ex vivo models for training in endoscopic sphincterotomy (ES) and endoscopic papillectomy (EP).

OBJECTIVE

We describe in vivo and ex vivo training pig models that use a simulated papilla for hands-on teaching of ES and EP.

DESIGN

Animal experiment.

SETTING

A referral center.

MATERIALS AND INTERVENTIONS

Hyaluronate solution (0.4%) was injected submucosally using a 25-gauge sclerotherapy needle to create a submucosal bleb by using porcine in vivo stomach, ex vivo stomach, and ex vivo rectum. ES and EP were then performed by using a pull-type sphincterotome and snare, respectively.

MAIN OUTCOME MEASUREMENT

The feasibility of creating a simulated papilla for ES and EP procedures was tested by experienced and nonexperienced ERCP endoscopists.

RESULTS

Creation of a hemispheroidal bulge was successful in 13 of 17 (76%) areas within an in vivo stomach, 13 of 16 (81%) areas of an ex vivo stomach, and 16 of 16 (100%) areas in an ex vivo rectum. In the in vivo stomach model, ES was successfully and realistically performed on the anterior wall of the stomach rather than in other walls. In the ex vivo stomach model, endoscopists experienced in ERCP and trainees performed ES without difficulty, whereas it was difficult or impossible for nonexperienced trainees to perform ES. In the ex vivo rectum model, all 3 endoscopists were able to complete not only ES but also EP.

LIMITATIONS

Pilot study.

CONCLUSIONS

Although further studies are necessary to evaluate the reproducibility and cost-effectiveness, this novel pig model appears useful for ES and EP training.

Warning for unprincipled colorectal endoscopic submucosal dissection: accurate diagnosis and reasonable treatment strategy

Piecemeal endoscopic mucosal resection (EMR) is generally indicated for laterally spreading tumors (LST) >2 cm in diameter. However, the segmentation of adenomatous parts does not affect the histopathological diagnosis and completeness of cure. Thus, possible indications for piecemeal EMR are both adenomatous homogenous-type granular-type LST (LST-G) and LST-G as carcinoma in adenoma without segmentalizing the carcinomatous part. Diagnosis of the pit pattern using magnifying endoscopy is essential for determining the correct treatment and setting segmentation borders. In contrast, endoscopic submucosal dissection (ESD) is indicated for lesions requiring endoscopic en bloc excision, as it is difficult to use the snare technique for en bloc excisions such as in non-granular-type LST (LST-NG), especially for the pseudodepressed type, tumors with a type VI pit pattern, shallow invasive submucosal carcinoma, largedepressed tumors and large elevated lesions, which are often malignant (e.g. nodular mixed-type LST-G). Other lesions, such as intramucosal tumor accompanied by submucosal fibrosis, induced by biopsy or peristalsis of the lesion; sporadic localized tumors that occur due to chronic inflammation, including ulcerative colitis; and local residual early carcinoma after endoscopic treatment, are also indications for ESD. In clinical practice, an efficient endoscopic treatment with segregation of ESD from piecemeal EMR should be carried out after a comprehensive evaluation of the completeness of cure, safety, clinical simplicity, and cost-benefit, based on an accurate preoperative diagnosis.

A novel gel provides durable submucosal cushion for endoscopic mucosal resection and endoscopic submucosal dissection

BACKGROUND

Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) have transformed the ability to endoscopically remove superficial lesions throughout the gastrointestinal tract. The purpose of this study was to determine the properties and safety of a novel gel designed for the purpose of submucosal injection for EMR and ESD.

METHODS

Upper endoscopy was performed in six Yorkshire pigs with 5-8 submucosal injections of varying amounts of Cook Medical (Bloomington, IN) gel were delivered in the stomach of each animal. A submucosal bleb of 1-2 ml normal saline was created followed by subsequent injection of 1-5 ml of the gel. Four animals were immediately euthanized and necropsy was performed after gel delivery and in two pigs; repeat endoscopy was performed after 4 weeks followed by necropsy.

RESULTS

Thirty-nine submucosal injections were performed in six pigs. Every injection resulted in adequate mucosal lifting with a shoulder and defined margin and no cases of gel extravasation. Twenty-seven injections were performed in four pigs followed by immediate necropsy. The submucosal cushion was still present at the time of organ extraction without evidence of perforation, bleeding or tissue damage. Unroofing of the mucosal layer demonstrated a clean submucosal tissue dissection without bleeding or tissue damage. Twelve submucosal injections were performed in two pigs, and repeat endoscopy at 4 weeks demonstrated persistent submucosal cushion without evidence of mucosal ischemia or ulceration. Necropsy demonstrated no evidence of perforation, bleeding, or gel extravasation. Unroofing the mucosa confirmed a clean submucosal dissection. The injectate did not result in mesenteric fibroinflammatory reaction, tissue damage, or adhesion formation after 4 weeks.

CONCLUSIONS

The gel appears to be a safe injectate that provides a submucosal cushion with a duration that is longer than other available injectates for EMR and ESD. The clean submucosal dissection may decrease the length of these procedures while minimizing complications.

Endoscopic resection of large colon polyps

Endoscopic resection, including polypectomy, endoscopic mucosal resection, and endoscopic submucosal dissection, is the preferred treatment method of large colorectal polyps. Its safety and efficacy have been shown. Endoscopic removal techniques are important because they provide a resection specimen for precise histopathologic staging to further direct diagnosis, prognosis, and management decisions. Used according to its indications, it provides curative resection and obviates the higher morbidity, mortality, and cost associated with alternative surgical treatment.

Carbon dioxide insufflation reduces number of postprocedure admissions after endoscopic resection of large colonic lesions: a prospective cohort study

BACKGROUND

Endoscopic resection (ER) for large colonic lesions is a safe and effective outpatient treatment. Postprocedural pain creates concern for perforation and often results in postprocedure admission (PPA). Carbon dioxide (CO(2)) insufflation has been shown to reduce pain scores after routine colonoscopy, but an influence on more critical outcomes such as PPA has not been shown.

OBJECTIVE

To assess the outcomes of patients undergoing ER for large colonic lesions, comparing those having air versus those having CO(2) insufflation.

DESIGN

Prospective, observational, cohort study.

SETTING

Academic, high-volume, tertiary-care referral center.

PATIENTS

Consecutive patients referred for ER of sessile colorectal polyps ≥20 mm.

INTERVENTION

ER with air or CO(2).

MAIN OUTCOME MEASUREMENTS

Rates of PPA, technical outcomes, complication rates.

RESULTS

ER was performed on 575 lesions ≥20 mm, 228 with CO(2) insufflation. Mean lesion size was 36.5 mm. Lesion and patient characteristics were similar in both groups. The use of CO(2) was associated with a 62% decrease in the PPA rate from 8.9% to 3.4% (P = .01). This was mainly because of an 82% decrease in PPA for pain from 5.7% to 1.0% (P = .006). There were no significant difference in the rates of complications. Multiple logistical regression was performed. The adjusted odds ratio (OR) of PPA (OR 0.39; 95% confidence interval [CI], 0.16-0.95; P = .04) and PPA for pain (OR 0.18; 95% CI, 0.04-0.78; P = .02) in the CO(2) group remained significant.

LIMITATIONS

Single center, nonrandomized study.

CONCLUSION

CO(2) insufflation significantly reduces PPA after ER of large colonic lesions, primarily because of reduced PPA for pain. CO(2) insufflation should be routinely used during ER of large colonic lesions.

Wide field endoscopic resection for advanced colonic mucosal neoplasia: current status and future directions

Most colonic adenomas are ≤ 10 mm and are routinely treated by colonoscopic polypectomy with long-term health benefits. Nonpolypoid lesions ≥ 20 mm, whether sessile or flat and laterally spreading, are forms of advanced mucosal neoplasia that cannot be managed by conventional polypectomy and are often referred for surgery. However, the majority of these lesions when carefully assessed are found to be noninvasive and can be safely and effectively treated by advanced endoscopic techniques including endoscopic mucosal resection or endoscopic submucosal dissection with resultant cost, morbidity, and mortality benefits. Lesion assessment is a critical component. Enhanced imaging methods provide the opportunity for accurate pathological characterization, informing treatment decisions, without the need for previous histologic confirmation. Techniques of advanced endoscopic resection are still in evolution and further improvements, including hybrid techniques, bringing less technically challenging and shorter procedures with superior safety can be reasonably expected in the next decade. Safety is a fundamental consideration. Methods of early recognition of complications, risk stratification, and management pathways are being developed and refined. Standardization, validation, and adoption of these technological developments will improve endoscopic interpretation and therapy and in combination with an increased understanding of adenoma molecular biology, will result in a progressively more individualized lesion-specific endoscopic approach. The future of advanced endoscopic resection in the colon is promising, and the next few years should see the boundaries of endoscopic resection expand well beyond the limits of what we know today.

Giant laterally spreading tumors of the duodenum: endoscopic resection outcomes, limitations, and caveats

BACKGROUND

Giant hemicircumferential and greater nonampullary duodenal adenomas or laterally spreading tumors (LSTs) may be amenable to safe endoscopic resection, but little data exists on outcomes or risk stratification.

DESIGN

We interrogated a prospectively maintained database of all patients who underwent endoscopic resection between January 2008 and November 2010. The resection technique was standardized. Major complications were defined as perforation, bleeding requiring readmission with hemoglobin drop of more than 20 g/L, or other substantial deviations from the usual clinical course. Outcomes were analyzed in 2 groups: giant lesions (>30 mm) and conventional duodenal polyps (<30 mm in diameter). Statistical evaluation was performed by using a χ(2) test.

RESULTS

A total of 50 nonampullary duodenal polyps and LSTs were resected from 46 patients (23 men, mean age 59.4 years, range 35-83 years). Nineteen were giant hemicircumferential and greater LSTs (mean size 40.5 mm, range 30-80 mm), and 31 were less than 30 mm in diameter (mean size 14.5 mm, range 5-25 mm). Intraprocedural bleeding occurred more frequently in giant lesions (57.8% vs 19.3%, P = .005) and was treated with a combination of soft coagulation and endoscopic clips with hemostasis achieved in all cases. Major complications, mostly bleeding related, occurred in 5 patients (26.3%) with giant lesions and 1 patient (3.2%) with a smaller lesion (P = .014). There were no deaths.

LIMITATION

Retrospective observational study in a tertiary center.

CONCLUSIONS

Endoscopic resection of giant nonampullary duodenal LSTs is a successful treatment. However, it is hazardous and associated with significantly higher complication rates, primarily bleeding, when compared with conventional duodenal polypectomy. Safer and more effective hemostatic tools are required in this high-risk location.

Endoscopic ampullectomy: a practical guide

Endoscopic ampullectomy is a minimally invasive method of treating superficial lesions of the ampulla of Vater. With careful patient selection and lesion assessment it is a safe and efficacious therapeutic procedure that can obviate the need for potentially major surgical intervention. Strategies for safe and successful endoscopic ampullectomy with a focus on resection technique and recognition and management of complications are presented.

Beyond the snare: technically accessible large en bloc colonic resection in the West: an animal study

BACKGROUND

Endoscopic submucosal dissection (ESD) and circumferential submucosal incision endoscopic mucosal resection (CSI-EMR) are techniques for en bloc excision of large sessile colonic lesions. Our aims were to compare the efficacy, safety and learning curve of colonic hybrid knife (HK) ESD versus CSI-EMR for en bloc excision of 50 mm diameter hemi-circumferential artificial lesions in a porcine model.

PATIENTS AND METHODS

Two separate 50 mm diameter areas of normal recto-sigmoid mucosa were marked out in each of ten pigs. One was excised with HK-ESD using succinylated gelatin (SG) submucosal injection. The other was isolated with CSI with the Insulated Tip Knife 2 followed by SG submucosal injection then EMR with a large snare. Euthanasia and colectomy was performed at 72 h followed by blinded histopathology assessment.

RESULTS

En bloc excision rates were: HK-ESD 100% versus CSI-EMR 20% (P = 0.008). The mean number of resections per lesion was HK-ESD 1 versus CSI-EMR 3 (P = 0.001). The mean dimensions of the largest specimen per technique were HK-ESD 63 × 54 mm versus CSI-EMR 49 × 41 mm (P = 0.005). Procedure duration mean was HK-ESD 54 min versus CSI-EMR 22 min (P < 0.001). When procedure duration was adjusted for the size of the resected en bloc specimen, a statistically significant and accelerated learning effect was noted for HK-ESD (r = -0.83, P = 0.003). There were no perforations and no significant bleeding.

CONCLUSIONS

HK-ESD with SG submucosal injection is superior to CSI-EMR for en bloc excision of 50 mm diameter lesions in a porcine model. The technique is rapidly learnt. This novel approach may lower the barrier to colonic ESD for Western endoscopists.

Colonoscopy: basic principles and novel techniques

Colonoscopy is considered the 'gold standard' for detection and removal of premalignant lesions in the colon. However, studies suggest that colonoscopy is less protective for right-sided than for left-sided colorectal cancer. Optimizing the effectiveness of colonoscopy is a continuous process, and during the past decade several important quality indicators have been defined that can be used to measure the performance of colonoscopy and to identify areas for quality improvement. The quality of bowel preparation can be enhanced by split-dose regimens, which are superior to single-dose regimens. Cecal intubation rates should approximate 95% and can be optimized by good technique. In selected patients, specific devices can be used to facilitate cecal intubation. Adenoma detection rates should be monitored and exceed a minimum of 25% in men and 15% in women. To this aim, optimal withdrawal technique and adequate time for inspection are of utmost importance. Of all advanced imaging techniques, chromoendoscopy is the only technique with proven benefit for adenoma detection. Finally, the technique of polypectomy affects the number of complications as well as the success of completely removing a lesion. In this Review, we provide an overview of both standard and novel colonoscopy techniques and their impact on quality indicators.