Short- and long-term outcomes of standardized EMR of nonpolypoid (flat and depressed) colorectal lesions > or = 1 cm (with video)

Interventional gastroenterology in oncology

Cancer is one of the foremost health problems worldwide and is among the leading causes of death in the United States. Gastrointestinal tract cancers account for almost one third of the cancer-related mortality globally, making it one of the deadliest groups of cancers. Early diagnosis and prompt management are key to preventing cancer-related morbidity and mortality. With advancements in technology and endoscopic techniques, endoscopy has become the core in diagnosis and management of gastrointestinal tract cancers. In this extensive review, the authors discuss the role endoscopy plays in early detection, diagnosis, and management of esophageal, gastric, colorectal, pancreatic, ampullary, biliary tract, and small intestinal cancers.

Evolving management of colorectal polyps

Advances in endoscopic technology have led to increased success in colorectal cancer (CRC) screening and polyp management, with reduction of CRC incidence and mortality. Despite these advances, CRC is still one of the leading causes of cancer deaths, and half of all CRC develops from lesions that were missed during colonoscopy while one-fifth of CRC arise from prior incomplete resection. Techniques to improve polyp detection are needed, along with optimization of complete resection of any abnormal lesions that are found. This article will review the currently available endoscopic resection techniques and will discuss where they fit in the management of polyps of different sizes and types, such as pedunculated versus nonpedunculated, and those with or without suspected invasion.

Location, morphology and invasiveness of lateral spreading tumors in the colorectum differ between two large cohorts from an eastern and western country

BACKGROUND AND STUDY AIMS

Data from Japanese series show that surface morphology of laterally spreading tumors (LST) in the colon identifies lesions with different incidence and pattern of submucosal invasion. Such data from western countries are scarce. We compared clinical and histological features of LST in a western country and an eastern country, with special interest on mucosal invasiveness of LST, and investigated the effect of clinical factors on invasiveness in both countries.

PATIENTS AND METHODS

Patients with LST lesions ≥20mm were included from a multicenter prospective registry in Spain and from a retrospective registry from the National Cancer Center Hospital East, Japan. The primary outcome was the presence of submucosal invasion in LST. The secondary outcome was the presence of high-risk histology, defined as high-grade dysplasia or submucosal invasion.

RESULTS

We evaluated 1102 patients in Spain and 663 in Japan. Morphological and histological characteristics differed. The prevalence of submucosal invasion in Japan was six-fold the prevalence in Spain (Prevalence Ratio PR=5.66; 95%CI: 3.96, 8.08), and the prevalence of high-risk histology was 1.5 higher (PR=1.44; 95%CI: 1.31, 1.58). Compared to the granular homogeneous type and adjusted by clinical features, granular mixed, flat elevated, and pseudo-depressed types were associated with higher odds of submucosal invasion in Japan, whereas only the pseudo-depressed type showed higher risk in Spain. Regarding high-risk histology, both granular mixed and pseudo-depressed were associated with higher odds in Japan, compared with only the granular mixed type in Spain.

CONCLUSION

This study reveals differences in location, morphology and invasiveness of LST in an eastern and a western cohort.

An endoscopic treatment strategy for superficial tumors in patients with ulcerative colitis

BACKGROUND AND AIM

Endoscopic resection is feasible for superficial tumors in patients with ulcerative colitis; however, endoscopic resection options have not been evaluated comprehensively. We evaluated the efficacy and safety of endoscopic submucosal dissection and endoscopic mucosal resection, and decision making regarding endoscopic resection options for patients with ulcerative colitis.

METHODS

Endoscopically treated tumors from patients with ulcerative colitis were analyzed retrospectively. We evaluated en bloc and R0 resection, adverse events, local tumor recurrence, and metachronous lesion occurrence rates.

RESULTS

We examined 102 tumors (mean size, 12 mm; non-polypoid, 55 tumors) from 74 patients with ulcerative colitis, of whom, 39 and 63 underwent endoscopic submucosal dissection and endoscopic mucosal resection, respectively. The R0 resection rate was significantly higher for endoscopic submucosal dissection (97%) than for endoscopic mucosal resection (80%) (P = 0.0015). For 11-20-mm tumors, the R0 resection rate was significantly higher for endoscopic submucosal dissection (94%) than for endoscopic mucosal resection (55%) (P = 0.0027); the endoscopic submucosal dissection and endoscopic mucosal resection R0 rates did not differ for ≤ 10-mm tumors. The non-polypoid tumor R0 resection rates were significantly higher for endoscopic submucosal dissection (100%) than for endoscopic mucosal resection (65%) (P < 0.001) and did not differ regarding the polypoid tumor R0 resection rates (75% vs 86%, P = 0.49). Four patients experienced intraoperative perforation during endoscopic submucosal dissection. No local recurrences occurred. Metachronous high-grade dysplasia occurred in three patients during surveillance.

CONCLUSIONS

In patients with ulcerative colitis, endoscopic submucosal dissection is suitable for ≥ 11-mm and non-polypoid tumors, whereas endoscopic mucosal resection is acceptable for ≤ 10-mm tumors.

Impact of observational training on endoscopic mucosal resection outcomes and competency for large colorectal polyps: single endoscopist experience

Background and study aims  Endoscopic mucosal resection (EMR) is standard treatment for large colorectal polyps. However, it is a specialized technique with limited data on the effectiveness of training methods to acquire this skill. The aim of this study was to evaluate the impact of observational training on EMR outcomes and competency in an early-stage endoscopist. Patients and methods  A single endoscopist completed comprehensive EMR training, which included knowledge acquisition and direct observation of EMR cases, and proctored supervision, during the third year of gastroenterology fellowship. After training, EMR was independently attempted on 142 consecutive, large (i. e., ≥ 20 mm), non-pedunculated colorectal polyps between July 2014 and December 2017 (mean age 61.7 years; mean polyp size 30.4 mm; en-bloc resection 55 %). Surveillance colonoscopy for evaluation of residual neoplasia was available for 86 % of the cases. Three primary outcomes were evaluated: endoscopic assessment of complete resection, rate of adverse events (AEs), and rate of residual neoplasia on surveillance colonoscopy. Results  Complete endoscopic resection was achieved in 93 % of cases, the rates of AEs and residual neoplasia were 7.8 % and 7.3 %, respectively. The rate of complete resection remained stable (at 85 % or greater) with increasing experience while rates of AEs and residual neoplasia peaked and decreased after 60 cases. Conclusions  An early-stage endoscopist can acquire the skills to perform effective EMR after completing observational training. At least 60 independent EMRs for large colorectal polyps were required to achieve a plateau for clinically meaningful outcomes.

Effect of prophylactic clip placement following endoscopic mucosal resection of large colorectal lesions on delayed polypectomy bleeding: A meta-analysis

BACKGROUND

The role of prophylactic clipping for the prevention of delayed polypectomy bleeding (DPB) remains unclear and conclusions from prior meta-analyses are limited due to the inclusion of variety of resection techniques and polyp sizes.

AIM

To conduct a meta-analysis on the effect of clipping on DPB following endoscopic mucosal resection (EMR) of colorectal lesions ≥ 20 mm.

METHODS

We performed a search of PubMed and the Cochrane library for studies comparing the effect of clipping vs no clipping on DPB following endoscopic resection. The Cochran Q test and I² were used to test for heterogeneity. Pooling was conducted using a random-effects model.

RESULTS

Thirteen studies with a total of 7794 polyps were identified, of which data was available on 1701 cases of EMR of lesions ≥ 20 mm. Prophylactic clipping was associated with a lower rate of DPB (1.4%) when compared to no clipping (5.2%) (pooled OR: 0.24, 95%CI: 0.12-0.50, P < 0.001) following EMR of lesions ≥ 20 mm. There was no significant heterogeneity among the studies (I² = 0%, P = 0.67).

CONLUSION

Prophylactic clipping may reduce DPB following EMR of large colorectal lesions. Future trials are needed to further identify risk factors and stratify high risk cases in order to implement a cost-effective preventive strategy.

Endoscopic resection of large colorectal adenomas - clinical experience of a tertiary referral centre

AIM

Colorectal cancer is a leading cause of cancer-related mortality. Adenomatous polyps are typically resected endoscopically to prevent cancer while giant and complex polyps are managed surgically. No criteria clearly define the indications for surgical vs endoscopic resection. Our aim was to evaluate factors associated with the short-term efficacy and safety of endoscopic resection of large (≥ 20 mm) and giant (≥ 40 mm) adenomas.

METHOD

Consecutive cases with colonic adenomas larger than 20 mm resected endoscopically were included. Endoscopic, clinical and histological details of polyps were recorded as well as the need for surgical resection.

RESULT

A total of 351 resections were included. The average adenoma diameter was 30.34 ± 10.66 mm. Surgery was recommended in 21 (5.98%) cases. In a multivariate analysis for efficacy, two variables were independent risk factors for surgery: adenoma size [OR 1.08 (95% CI: 1.04-1.12)] and caecal location [5.97(1.60-22.33)]. Postpolypectomy complications were documented in 85 (24.2%) cases: bleeding 69 (19.7%), perforations 8(2.3%) and significant discomfort 15(4.3%). Twenty-one patients (6.0%) developed serious complications requiring further hospitalization. In multivariate analysis for safety, independent risk factors for postpolypectomy complications included adenoma size [1.04 (1.06-1.01)], polyp morphology [sessile 2.55 (1.45-4.51), flat 2.40 (1.04-5.52)] and submucosal adrenaline injection [1.87 (1.11-3.20)]. Increments of 1 mm in adenoma diameter beyond 20 mm increased the need for surgery by 8% and the risk of complications by 4%.

CONCLUSION

Resection of large or giant adenomas is generally a safe procedure. Although adenoma size and morphology are significant predictors of efficacy and safety, each case should be individually evaluated in a specialist unit for feasibility of endoscopic resection.

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.

Patients With Nonpolypoid (Flat and Depressed) Colorectal Neoplasms at Increased Risk for Advanced Neoplasias, Compared With Patients With Polypoid Neoplasms

BACKGROUND & AIMS

Nonpolypoid colorectal neoplasms (NP-CRNs) are more likely to contain high-grade dysplasia or early-stage cancer than polypoid neoplasms. We aimed to determine the long-term outcomes of patients with at least 1 NP-CRN.

METHODS

We performed a longitudinal cohort study of 4454 patients at a Veterans' Affairs hospital who underwent colonoscopy from 2000 through 2005; 341 were found to have 1 or more NP-CRNs and were matched (3:1) with patients found to have 1 or more polypoid neoplasms (controls, n = 1025). We collected and analyzed data on baseline colonoscopy findings and first follow-up colonoscopy results through August 2014. We calculated the incidence of advanced neoplasia at first follow-up colonoscopy, as defined by the presence of ≥1 tubular or sessile serrated adenomas ≥10 mm in diameter, tubulovillous adenoma, high-grade dysplasia, or invasive cancer.

RESULTS

A significantly higher proportion of patients with 1 or more NP-CRNs (16.0%) were found to have advanced neoplasia at their first follow-up colonoscopy than controls (8.6%); the adjusted risk ratio was 1.6 (95% confidence interval, 1.05-2.6; P = .03). A significantly higher proportion of patients with 1 or more NP-CRNs were found to have additional NP-CRNs at the follow-up colonoscopy (17%) than controls (7%; relative risk, 2.3; 95% confidence interval, 1.5-3.5; P < .001). Similar proportions of patients in each group developed cancers after colonoscopy.

CONCLUSIONS

In a longitudinal cohort study, we found that patients with NP-CRN were more likely to develop additional NP-CRNs and to have advanced neoplasms at their first follow-up colonoscopy than patients with only polypoid neoplasms. However, patients with NP-CRN were not more likely to develop cancers after colonoscopy when surveillance guidelines were followed. Larger studies are needed to determine risk of colorectal cancer in patients with NP-CRN.

Endoscopic Management of Large (≥2 cm) Non-pedunculated Colorectal Polyps: Impact of Polyp Morphology on Outcomes

BACKGROUND AND AIMS

Referrals for endoscopic management of large non-pedunculated (NP) colorectal polyps have increased as new techniques have emerged. The outcomes for referred large NP polyps based on the polyp morphology were investigated METHODS: A retrospective review of patients referred for large (≥20 mm) NP polyp management from January 2010 through June 2014 was completed. Polyp morphology was classified as either a NP polyp with depression (M1) or NP polyp with no depression (M0). Differences in treatment, histology, adverse events, outcomes at follow-up including residual disease, and need for surgical treatment were determined by morphology for all NP polyps ≥20 mm in size.

RESULTS

One-hundred and sixty-nine M1 and 136 M0 polyps ≥20 mm were removed endoscopically during the review period. Mean size was 31.9 ± 11.0 mm in M1, and 26.8 ± 9.5 mm in M0 group (p < 0.0001). En bloc resection was possible in 18.3 % of M1 and 30.9 % of M0 lesions (p = 0.011) with endoscopic submucosal dissection used in 13 and 2.2 % of polyps, respectively (p < 0.0001). Residual polyp was found in 26.5 % (27/102) of M1 and 13.6 % (12/88) of M0 patients at surveillance colonoscopy (p = 0.029). On multivariate analysis, piecemeal resection and M1 morphology showed significant association with residual polyp (OR 4.23, 95 % CI 1.23-14.59, p = 0.022, and OR 2.15, 95 % CI 1.004-4.62, p = 0.049, respectively).

CONCLUSION

Effective endoscopic management of large NP colorectal polyps, especially polyps without depression (M0), can be accomplished in the great majority of patients. Polyp morphology, particularly the presence or absence of depression, is a useful tool which influenced treatment, histology, and outcomes.

Endoscopic mucosal resection: learning curve for large nonpolypoid colorectal neoplasia

BACKGROUND AND AIMS

Colorectal EMR for nonpolypoid neoplasia achieves better outcomes when performed by expert endoscopists. The time point at which the endoscopist achieves expert level remains to be defined. The objective of this study was to establish a learning curve of colorectal EMR for nonpolypoid neoplasia based on residual tissue on surveillance colonoscopy and adverse event rate.

METHODS

Five hundred seventy-eight consecutive patients underwent EMR of colorectal neoplasia by 1 of 3 primary endoscopists between December 2004 and September 2013 in a tertiary academic center. Primary analyses focused on the largest lesion for patients with more than 1 lesion (median age, 69 years; median polyp size, 30 mm; 51% en bloc resection). Data on surveillance colonoscopy were available for 74%. Learning curves were calculated for each of the 3 main outcome measurements: the presence of residual neoplasia on surveillance colonoscopy, endoscopic assessment of incomplete EMR, and the occurrence of an immediate bleeding adverse event.

RESULTS

Residual neoplasia on surveillance colonoscopy was present for 23.2% of patients, the rate of endoscopist-assessed incomplete EMR was 27.6%, and immediate bleeding adverse events occurred in 6.9% of patients. Although there was between-endoscopist variability, the overall rates of residual neoplasia and incomplete EMR decreased to below 20% to 25% after 100 EMRs; initial decreases in both rates were observed for earlier EMRs. Immediate bleeding adverse events occurred at a low frequency for each endoscopist across all EMRs. Perforation requiring surgical intervention occurred in 1 patient (0.2%).

CONCLUSIONS

This study demonstrated that an unexpectedly high number of 100 colorectal EMR procedures for large nonpolypoid colorectal neoplasia are required to achieve a plateau phase for crucial outcomes.

Large Sessile Serrated Polyps Can Be Safely and Effectively Removed by Endoscopic Mucosal Resection

BACKGROUND & AIMS

As many as 50% of large sessile serrated adenomas/polyps (SSPs) are removed incompletely, which is significant because SSPs have been implicated in the development of interval cancers. It is unclear if endoscopic mucosal resection (EMR) is an optimal method for removal of SSPs. We assessed the efficacy and safety of removal of SSPs 10 mm and larger using a standardized inject-and-cut EMR technique.

METHODS

We performed a retrospective analysis of colonoscopy data, collected over 7 years (2007-2013) at 2 centers, from 199 patients with proximal colon SSPs 10 mm and larger (251 polyps) removed by EMR by 4 endoscopists. The primary outcome measure was local recurrence. The secondary outcome measure was safety.

RESULTS

At the index colonoscopy, patients had a median of 1 serrated lesion (range, 1-12) and 1 nonserrated neoplastic lesion (range, 0-15). The mean SSP size was 15.9 ± 5.3 mm; most were superficially elevated (84.5%) and located in the ascending colon (51%), and 3 SSPs (1.2%) had dysplasia. Surveillance colonoscopies were performed on 138 patients (69.3%) over a mean follow-up period of 25.5 ± 17.4 months. Of these patients, 5 had local recurrences (3.6%; 95% confidence interval, 0.5%-6.7%), detected after 17.8 ± 15.4 months, with a median size of 4 mm. No patients developed postprocedural bleeding, perforation, or advanced colon cancer, or had a death related to the index colorectal lesion during the study period.

CONCLUSIONS

Inject-and-cut EMR is a safe and effective technique for the resection of SSPs. Less than 5% of patients have a local recurrence, which is usually small and can be treated endoscopically.

Outcome and risk of recurrence for endoscopic resection of colonic superficial neoplastic lesions over 2 cm in diameter

BACKGROUND

Large colorectal superficial neoplastic lesions are challenging to remove. This study aimed to assess the outcomes of routine endoscopic resection of large (≥2 cm and <3 cm) and giant (≥3 cm) lesions.

METHODS

From 4587 endoscopic resections, 265 (5.7%) large and giant lesions were removed in 249 patients. We retrospectively analyzed 125 patients (141 endoscopic mucosal resection, 73 large and 68 giant lesions) with a follow-up of 6-12 months. Rate of en bloc and piecemeal resection, recurrence and risk factors were analyzed.

RESULTS

En bloc was performed in 92 cases (65.2%) and piecemeal resection in 49 (34.8%). A complete endoscopic resection was achieved in 139 cases (98.5%) with radical resection in 84/139 cases (60.4%). Argon plasma coagulation was applied in 18/141 lesions (12.8%). A recurrence occurred in 16/139 lesions (11.5%). The risk of recurrence at one year was significantly higher for giant than large lesions (p=0.03). The recurrence risk was higher in treated than in non-argon plasma coagulation treated lesions (p=0.01).

CONCLUSIONS

endoscopic mucosal resection is a safe and effective routine treatment for large superficial neoplastic lesions. The risk factors for recurrence include giant size, non-protruding morphology, piecemeal technique and argon plasma coagulation.

Practice parameters for early colon cancer management: Italian Society of Colorectal Surgery (Società Italiana di Chirurgia Colo-Rettale; SICCR) guidelines

Early colon cancer (ECC) has been defined as a carcinoma with invasion limited to the submucosa regardless of lymph node status and according to the Royal College of Pathologists as TNM stage T1 NX M0. As the potential risk of lymph node metastasis ranges from 6 to 17% and the preoperative assessment of lymph node metastasis is not reliable, the management of ECC is still controversial, varying from endoscopic to radical resection. A meeting on recent advances on the management of colorectal polyps endorsed by the Italian Society of Colorectal Surgery (SICCR) took place in April 2014, in Genoa (Italy). Based on this material the SICCR decided to issue guidelines updating the evidence and to write a position statement paper in order to define the diagnostic and therapeutic strategy for ECC treatment in context of the Italian healthcare system.

Interval colorectal cancers in inflammatory bowel disease: the grim statistics and true stories

Interval colorectal cancers (CRCs) may account for approximately one half of all CRCs identified during IBD surveillance. The etiology of interval CRCs is multifactorial, with procedural factors likely to play a major role. Molecular events promoted by inflamed mucosa may augment the cancer risk and perhaps explain some interval CRCs. This article reviews key studies relating to CRC risk in the patient with IBD, paying particular attention to the occurrence of interval CRCs. The most common factors implicated in the etiology of interval CRCs, in particular missed, incompletely resected lesions, the adherence to recommended surveillance intervals and biologic pathways associated with a faster progression to cancer are examined. Basic concepts for quality and effectiveness of colonoscopic surveillance in IBD are summarized.

Use of prototype two-channel endoscope with elevator enables larger lift-and-snare endoscopic mucosal resection in a porcine model

Background: Flat and depressed lesions are becoming increasingly recognized in the esophagus, stomach, and colon. Various techniques have been described for endoscopic mucosal resection (EMR) of these lesions.

Aims: To evaluate the efficacy of lift-grasp-cut EMR using a prototype dual-channel forward-viewing endoscope with an instrument elevator in one accessory channel (dual-channel elevator scope) as compared to standard dual-channel endoscopes.

Methods: EMR was performed using a lift-grasp-cut technique on normal flat rectosigmoid or gastric mucosa in live porcine models after submucosal injection of 4 mL of saline using a dual-channel elevator scope or a standard dual-channel endoscope. With the dual-channel elevator scope, the elevator was used to attain further lifting of the mucosa. The primary endpoint was size of the EMR specimen and the secondary endpoint was number of complications.

Results: Twelve experiments were performed (six gastric and six colonic). Mean specimen diameter was 2.27 cm with the dual-channel elevator scope and 1.34 cm with the dual-channel endoscope (P = 0.018). Two colonic perforations occurred with the dual-channel endoscope, vs no complications with the dual-channel elevator scope.

Conclusions: The increased lift of the mucosal epithelium, through use of the dual-channel elevator scope, allows for larger EMR when using a lift-grasp-cut technique. Noting the thin nature of the porcine colonic wall, use of the elevator may also make this technique safer.

Endoscopic resection for superficial colorectal neoplasia in Italy: a prospective multicentre study

BACKGROUND

Since there are few prospective studies on colorectal endoscopic resection to date, we aimed to prospectively assess safety and efficacy of endoscopic resection in a cohort of Italian patients.

METHODS

Prospective multicentre assessment of resection of sessile polyps or non-polypoid lesions ≥10mm in size or smaller (if depressed). Outcome measures included complete excision, morbidity, mortality, and residual/recurrence at 12 months.

RESULTS

Overall, 1012 resections in 928 patients were analysed (62.4% sessile polyps, 28.8% laterally spreading tumours, 8.7% depressed non-polypoid lesions). Lesions were prevalent in the proximal colon. En bloc resection was possible in 715/1012 cases (70.7%), whereas piecemeal resection was required in 297 (29.3%). Endoscopically complete excision was achieved in 866 cases (85.6%). Adverse events occurred in 83 (8.2%), and no deaths occurred. Independent predictors of 12-month residual/recurrence were the location of the lesion in the proximal colon (OR 2.22 [95% CI 1.16-4.26]; p=0.015) and piecemeal endoscopic resection (OR 2.76 [95% CI 1.56-4.87]; p=0.0005). Limitations of the study were: potential expertise bias, no data on eligible and potentially resectable excluded lesions, high percentage of lesions<20mm, follow-up limited to 1 year.

CONCLUSION

In this registry study the endoscopic resection of colorectal lesions was safe and achieved high rates of long-term endoscopic clearance.

Standardized long-term follow-up after endoscopic resection of large, nonpedunculated colorectal lesions: a prospective two-center study

OBJECTIVES

Endoscopic removal of large, nonpedunculated colorectal lesions is challenging. Long-term outcome data based on standardized protocols, including detailed inspection of the resection site, are scarce. The aims of the present study were to evaluate the safety and efficacy of endoscopic resection (ER) of large, nonpedunculated lesions (LNLs; >20 mm) and to assess the long-term recurrence rate afterward.

METHODS

A total of 243 consecutive patients (141 men, 102 women) with 252 adenomas (>20 mm) was followed up using a standardized protocol after complete ER. After endoscopic treatment, the patients received standardized follow-up examinations after 3-6 months and 12 months. The postpolypectomy scar was re-examined, assessed for residual neoplasia, and biopsied at each follow-up colonoscopy.

RESULTS

Evident residual neoplasia was noted after 3-6 months in 58 of 183 lesions (31.69%). After 12 months, 126 LNLs were examined, with 19 late recurrences (16.37%). Twenty-one (6.5%) postpolypectomy scars were not detected during 321 surveillance examinations. Biopsy evidence of residual/recurrent lesions was found in 16 of 228 macroscopically inconspicuous polypectomy scars (7%). All residual adenomas were treated using ER and/or argon plasma coagulation. There were 43 complications with the 252 lesions (17%), including 20 major complications (7.9%), all managed conservatively.

CONCLUSIONS

A detailed study design with systematic biopsies of inconspicuous scars reveals a significant number of residual adenomas after completed resection. However, these residual neoplasias can be effectively treated at follow-up colonoscopies.

Outcomes of repeat colonoscopy in patients with polyps referred for surgery without biopsy-proven cancer

BACKGROUND

Despite advances in endoscopic treatment, many colonic adenomas are still referred for surgical resection. There is a paucity of data on the suitability of these lesions for endoscopic treatment.

OBJECTIVE

To analyze the results of routine repeat colonoscopy in patients referred for surgical resection of colon polyps without biopsy-proven cancer.

DESIGN

Retrospective review.

SETTING

University hospital.

PATIENTS

Patients referred to a colorectal surgeon for surgical resection of a polyp without biopsy-proven cancer.

INTERVENTIONS

Repeat colonoscopy.

MAIN OUTCOME MEASUREMENTS

The rate of successful endoscopic treatment.

RESULTS

There were 38 lesions in 36 patients; 71% of the lesions were noncancerous and were successfully treated endoscopically. In 26% of the lesions, previous removal was attempted by the referring physician but was unsuccessful. The adenoma recurrence rate was 50%, but all recurrences were treated endoscopically and none were cancerous. Two patients were admitted for overnight observation. There were no major adverse events.

LIMITATIONS

Single center, retrospective.

CONCLUSIONS

In the absence of biopsy-proven invasive cancer, it is appropriate to reevaluate patients referred for surgical resection by repeat colonoscopy at an expert center.

Endoscopic appearance of proximal colorectal neoplasms and potential implications for colonoscopy in cancer prevention

BACKGROUND

In everyday practice, the use of colonoscopy for the prevention of colorectal cancer (CRC) is less effective in the proximal than the distal colon. A potential explanation for this is that proximal neoplasms have a more subtle endoscopic appearance, making them more likely to be overlooked.

OBJECTIVE

To investigate the differences in endoscopic appearance, ie, diminutive size and nonpolypoid shape, of proximal compared with distal colorectal neoplasms.

DESIGN

Cross-sectional, single-center study.

SETTING

Endoscopists at the Maastricht University Medical Center in the Netherlands who were previously trained in the detection and classification of nonpolypoid colorectal lesions.

PATIENTS

Consecutive patients undergoing elective colonoscopy.

MAIN OUTCOME MEASUREMENTS

Endoscopic appearance, ie, diminutive size (<6 mm) or nonpolypoid shape (height less than half of the diameter) of colorectal adenomas and serrated polyps (SPs), with a focus on adenomas with advanced histology, ie, high-grade dysplasia or early CRC and SPs with dysplasia or large size.

RESULTS

We included 3720 consecutive patients with 2106 adenomas and 941 SPs. We found that in both men and women, proximal adenomas with high-grade dysplasia/early CRC (n = 181) were more likely to be diminutive or nonpolypoid than distal ones (76.3% vs 26.2%; odds ratio [OR] 9.24; 95% CI, 4.45-19.2; P < .001). Of the proximal adenomas, 84.4% were diminutive or nonpolypoid compared with 68.0% of the distal ones (OR 2.66; 95% CI, 2.14-3.29; P < .001). Likewise, large/dysplastic SPs in the proximal colon were more often nonpolypoid than distal ones (66.2% vs 27.8%; OR 5.51; 95% CI, 2.79-10.9; P < .001).

LIMITATIONS

Inclusion of both symptomatic and asymptomatic patients.

CONCLUSIONS

Proximal colorectal neoplasms with advanced histology frequently are small or have a nonpolypoid appearance. These findings support careful inspection of the proximal colon, if quality of cancer prevention with the use of colonoscopy is to be optimized.

Proficiency in the diagnosis of nonpolypoid colorectal neoplasm yields high adenoma detection rates

BACKGROUND AND AIMS

Current efforts to prevent colorectal cancer focus on the detection and removal of neoplasms. Nonpolypoid colorectal neoplasms (NP-CRN) have a subtle appearance that can be difficult to recognize during colonoscopy. Endoscopists must first be familiar with the patterns of NP-CRN in order to detect and diagnose them. We studied the adenoma detection rates of endoscopists who had trained to detect NP-CRN, versus endoscopists who had not.

DESIGN

Retrospective Nested Case Control Study.

SETTING

Outpatient Screening Colonoscopy.

PARTICIPANTS

Adult Veterans.

INTERVENTION

Proficiency in the features and diagnosis of NP-CRN.

MAIN OUTCOMES MEASUREMENTS

Adenoma detection.

RESULTS

In total, 462 patients had screening colonoscopies-267 by colonoscopists who had trained in the features and diagnosis of NP-CRN. Patient characteristics were similar between groups-the majority were men with a mean age of 62 ± 6 years. Neoplasia was more prevalent (45.7 vs. 34.9%; p = 0.02) in patients evaluated by the trained compared to the conventionally trained group. Trained colonoscopists had a higher adenoma detection rate (0.76 vs. 0.54 adenomas per patient, p < 0.001); removed a higher proportion of neoplasia (77 vs. 35%, p < 0.001); and more frequently diagnosed NP-CRN lesions (OR 2.98, 95% CI: 1.46-6.08) compared to colonoscopists without supplemental training.

CONCLUSIONS

Endoscopists who are proficient in the detection of NP-CRN had significantly higher adenoma detection rates-of both polypoid and flat adenomas-compared to endoscopists without training, and were more specific in resection of adenomatous over hyperplastic lesions.

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.

Nonpolypoid colorectal neoplasms: gender differences in prevalence and malignant potential

OBJECTIVE

Colonoscopy may fail to prevent colorectal cancer, especially in the proximal colon and in women. Nonpolypoid colorectal neoplasms may potentially explain some of these post-colonoscopy cancers. In the present study, we aimed to examine the prevalence and malignant potential of nonpolypoid colorectal neoplasms in a large population, with special attention to gender and location.

METHODS

We performed a cross-sectional study of all consecutive patients undergoing elective colonoscopy at a single academic medical center. The endoscopists were familiarized on the detection and treatment of nonpolypoid lesions. Advanced histology was defined by the presence of high-grade dysplasia or early cancer.

RESULTS

We included 2310 patients (53.9% women, mean age 58.4 years) with 2143 colorectal polyps. Prevalences of colorectal neoplasms and nonpolypoid colorectal neoplasms were lower in women than in men (20.9% vs. 33.7%, p < 0.001 and 3.0% vs. 5.5%, p = 0.002). In women, nonpolypoid colorectal neoplasms were significantly more likely to contain advanced histology than polypoid ones (OR 2.89, 95% CI 1.24-6.74, p = 0.01), while this was not the case in men (OR 0.91, 95% CI 0.40-2.06, p = 0.83). Proximal neoplasms with advanced histology were more likely to be nonpolypoid than distal ones (OR 4.68, 95% CI 1.54-14.2, p = 0.006).

CONCLUSION

Nonpolypoid mechanisms may play an important role in colorectal carcinogenesis, in both women and men. Although women have fewer colorectal neoplasms than men, they have nonpolypoid colorectal neoplasms, which frequently contain advanced histology.

Endoscopic mucosal resection outcomes and prediction of submucosal cancer from advanced colonic mucosal neoplasia

BACKGROUND & AIMS

Large sessile colonic polyps usually are managed surgically, with significant morbidity and potential mortality. There have been few prospective, intention-to-treat, multicenter studies of endoscopic mucosal resection (EMR). We investigated whether endoscopic criteria can predict invasive disease and direct the optimal treatment strategy.

METHODS

The Australian Colonic Endoscopic (ACE) resection study group conducted a prospective, multicenter, observational study of all patients referred for EMR of sessile colorectal polyps that were 20 mm or greater in size (n=479, mean age, 68.5 y; mean lesion size, 35.6 mm). We analyzed data on lesion characteristics and procedural, clinical, and histologic outcomes. Multiple logistic regression analysis identified independent predictors of EMR efficacy and recurrence of adenoma, based on findings from follow-up colonoscopy examinations.

RESULTS

Risk factors for submucosal invasion were as follows: Paris classification 0-IIa+c morphology, nongranular surface, and Kudo pit pattern type V. The most commonly observed lesion (0-IIa granular) had a low rate of submucosal invasion (1.4%). EMR was effective at completely removing the polyp in a single session in 89.2% of patients; risk factors for lack of efficacy included a prior attempt at EMR (odds ratio [OR], 3.8; 95% confidence interval, 1.77-7.94; P=.001) and ileocecal valve involvement (OR, 3.4; 95% confidence interval, 1.20-9.52; P=.021). Independent predictors of recurrence after effective EMR were lesion size greater than 40 mm (OR, 4.37; 95% confidence interval, 2.43-7.88; P<.001) and use of argon plasma coagulation (OR, 3.51; 95% confidence interval, 1.69-7.27; P=.0017). There were no deaths from EMR; 83.7% of patients avoided surgery.

CONCLUSIONS

Large sessile colonic polyps can be managed safely and effectively by endoscopy. Endoscopic assessment identifies lesions at increased risk of containing submucosal cancer. The first EMR is an important determinant of patient outcome-a previous attempt is a significant risk factor for lack of efficacy.

Feasibility of salvage endoscopic mucosal resection by using a cap for remnant rectal carcinoids after primary EMR

BACKGROUND

Secondary endoscopic treatment for remnant lesions of rectal carcinoid tumors after primary EMR or polypectomy is technically difficult because of fibrosis of residual tissues. EMR by using a cap (EMR-C), a method to resect the submucosal layer by suction by using a transparent cap, may be feasible as a salvage treatment.

OBJECTIVE

To assess the feasibility of salvage EMR-C.

DESIGN

Retrospective analysis.

SETTING

Tertiary academic health care system.

PATIENTS

Thirty-one patients who were referred for salvage treatment of a failed en bloc excision of rectal carcinoid tumors after primary EMR or polypectomy between January 2007 and December 2009.

INTERVENTIONS

Salvage EMR-C for remnant carcinoid tumors in the rectum.

MAIN OUTCOME MEASUREMENTS

Rate of complete resection, complications, length of procedure, and recurrence rate.

RESULTS

The mean age of the patients was 52.0±11.8 years (range 30-78 years). The mean tumor size was 8.9±3.2 mm (range 5.0-13.0 mm). The mean procedure time was 9.1±3.7 minutes, and clear resection margins were pathologically confirmed in all 31 patients. The most common complication of salvage EMR-C was bleeding (7 patients, 22.6%), which was successfully treated by hemoclipping in all cases. The 1-year follow-up colonoscopy and CT results for all patients were negative for recurrence.

LIMITATIONS

Retrospective design and limited cases at a single center.

CONCLUSIONS

EMR-C is a feasible salvage therapeutic option for failed en bloc excision after primary endoscopic treatment of rectal carcinoid tumors.

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

OBJECTIVES

Succinylated gelatin (SG) is an inexpensive, safe, colloidal solution. It was superior to normal saline (NS) in a porcine colon endoscopic resection (ER) model. Our aim was to compare the efficacy, efficiency, and safety of ER with SG vs. NS.

METHODS

A randomized double-blind trial of submucosal injection with SG vs. NS was conducted for patients undergoing colonoscopy and ER for sessile lesions ≥20 mm in size at an Australian academic hospital endoscopy unit. The primary end point was the "Sydney Resection Quotient" (SRQ), defined as "lesion size in mm divided by the number of pieces to resect." This allows a comparison of technical outcomes for lesions of various sizes. A large lesion removed in fewer pieces gives a greater value.

RESULTS

Eighty patients (45 men, mean age 69) with lesions sized 20-100 mm were randomized. A total of 41 SG subjects were well matched to 39 NS subjects, with median (interquartile range) lesion size 40 mm (25-45) vs. 35 mm (30-50), respectively (P=0.382). Complete single-session lesion excision was 90% in both groups. There were no adverse events attributable to SG. The SRQ (median (interquartile range)) was SG 10.0 (7.5-20.0) vs. NS 5.9 (4.4-11.7), P=0.004. Other end points (median (interquartile range)) included fewer resections per lesion in the SG group: 3.0 (1.0-6.0) vs. NS 5.5 (3.0-10.0), P=0.028; fewer injections per lesion with SG: 2.0 (1.0-3.0) vs. NS 3.0 (2.0-11.0), P=0.002; lower injection volume: 14.5 ml (8.5-23.0) vs. NS 20.0 ml (16.0-46.0), P=0.009; and shorter procedure duration with SG: 12.0 min (8.0-28.0) vs. NS 24.5 min (15.0-36.0), P=0.006.

CONCLUSIONS

SG significantly improves SRQ by almost halving the number of resections for piecemeal ER. SG also safely halves procedure duration.

Endoscopic resection of gastrointestinal lesions: advancement in the application of endoscopic submucosal dissection

Curative endoscopic resection is now a viable option for a range of neoplastic lesions of the gastrointestinal tract (GIT) with low invasive potential. Risk of lymph node metastasis is the most important prognostic factor in selecting appropriate lesions for endoscopic therapy, and assessment of invasion depth is vital in this respect. To determine appropriate treatment, detailed endoscopic diagnosis and estimation of depth using magnifying chromoendoscopy is the gold standard in Japan. En bloc resection is the most desirable endoscopic therapy as risk of local recurrence is low and accurate histological diagnosis of invasion depth is possible. Endoscopic mucosal resection is established worldwide for the ablation of early neoplasms, but en bloc removal using this technique is limited to small lesions. Evidence suggests that a piecemeal resection technique has a higher local recurrence risk, therefore necessitating repeated surveillance endoscopy and further therapy. More advanced endoscopic techniques developed in Japan allow effective en bloc removal of early GIT neoplasms, regardless of size. This review discusses assessment of GIT lesions and options for endoscopic therapy with special reference to the introduction of endoscopic submucosal dissection into Western countries.

Endoscopic mucosal resection of non-polypoid colorectal neoplasm

Endoscopic mucosal resection (EMR) is preferred to standard polypectomy for the resection of non-polypoid lesions because these lesions can be technically difficult to capture with a snare; furthermore, without submucosal injection the underlying muscularis propria may be excessively coagulated or even inadvertently resected. Because the resection plane of EMR is in the middle or deeper part of the submucosa, EMR allows the precise depth of the lesion to be evaluated. Although the majority of non-polypoid lesions are adenomatous, non-polypoid colorectal neoplasm has a high association with advanced pathology, irrespective of size. Using EMR, a complete pathologic specimen is obtained, the risk of lymph node metastasis can be accurately assessed based on the depth of invasion, and patients can be suitably managed. Used according to its indications, EMR provides curative resection, and obviates the higher morbidity, mortality, and cost associated with surgical treatment.

Development of expertise in the detection and classification of non-polypoid colorectal neoplasia: Experience-based data at an academic GI unit

At its core, quality improvement in gastrointestinal (GI) practice relies on continuous training, education, and information among all health care providers, whether gastroenterologists, GI trainees, endoscopy nurses, or GI pathologists. Over the past few years, it became clear that objective criteria are needed to assess the quality of colonoscopy, such as cecum intubation rate, quality of bowel preparation, withdrawal time, and adenoma detection rate. In this context, development of competence among practicing endoscopists to adequately detect and treat non-polypoid colorectal neoplasms (NP-CRNs) deserves special attention. We describe a summary of the path to develop expertise in detection and management of NP-CRNs, based on experience at our academic GI unit.

Our perspective on endoscopic resection for colorectal neoplasms

Endoscopic mucosal resection (EMR) is a minimally invasive technique for effective treatment of early stage colorectal lesions with no invasive potential. However, the high frequency of local recurrence after piecemeal EMR for large lesions is considered a serious problem. In contrast, endoscopic submucosal dissection (ESD) allows en-bloc resection, irrespective of the lesion's size. ESD has been established as a standard method for the endoscopic removal of early cancers in the upper gastrointestinal tract in Japan. Although the use of ESD for colorectal lesions has been studied clinically, ESD is not yet established as a standard therapeutic method. We define the indications for en-bloc resection, based on extensive clinicopathological analyses, as a laterally spreading tumor (LST) non-granular type (LST-NG) lesion greater than 20 mm and an LST granular (LST-G) type lesion greater than 40 mm. Both of these lesions had a high submucosal invasion rate. Especially, LST-NG type lesions greater than 20 mm are technically difficult to remove completely even by piecemeal EMR and are considered a "definite indication for en-bloc resection". The ESD procedure is undoubtedly an ideal method to achieve en-bloc resection, however, the prevalences of suitable lesions among all neoplastic lesions and among all early cancers were not high (1.0% and 5.0%, respectively). Therefore, it is crucial to master more fundamental therapeutic techniques and have knowledge of surveillance strategy after endoscopic treatment.

In vitro porcine training model for colonic endoscopic submucosal dissection: an inexpensive and safe way to acquire a complex endoscopic technique

BACKGROUND

Colonic endoscopic submucosal dissection (ESD) has developed in recent years to permit en bloc resection of larger colorectal lesions that cannot be done by standard polypectomy or mucosal resection techniques. Colonic ESD is technically demanding and has a steep learning curve. Adequate training is essential to make ESD a reliable treatment for colorectal neoplasms. We aim to share our early experience with an in vitro porcine training model for colonic ESD.

METHOD

Resected porcine distal colon was used to set up a training model for ESD, which was performed as in human using a standard endoscope and dissecting devices. Size of the lesions, operation time, en bloc resection rate, and perforation rate were recorded.

RESULTS

Ten consecutive colonic ESD procedures were performed by a single endoscopist. Incomplete resection and perforation were encountered during the first two procedures. No perforation occurred in subsequent procedures and the operation time per task also decreased gradually. The setup cost for this model was only around US $30.

CONCLUSIONS

The in vitro porcine model is easy and inexpensive to set up. Our initial experience showed that the model could simulate colonic ESD in human and technical proficiency improved by repetition. This simple setup may be a promising training model for endoscopists working in areas with a low incidence of early gastric cancer.

Large endoscopic mucosal resection for colorectal tumors exceeding 4 cm

AIM: To evaluate the feasibility and the outcome of endoscopic mucosal resection (EMR) for large colorectal tumors exceeding 4 cm (LCRT) undergoing piecemeal resection.

METHODS: From January 2005 to April 2008, 146 digestive tumors larger than 2 cm were removed with the EMR technique in our department. Of these, 34 tumors were larger than 4 cm and piecemeal resection was carried out on 26 colorectal tumors. The mean age of the patients was 71 years. The mean follow-up duration was 12 mo.

RESULTS: LCRTs were located in the rectum, left colon, transverse colon and right colon in 58%, 15%, 4% and 23% of cases, respectively. All were sessile tumors larger than 4 cm with a mean size of 4.9 cm (4-10 cm). According to the Paris classification, 34% of the tumors were type Is, 58% type IIa, 4% type IIb and 4% type IIc. Pathological examination showed tubulous adenoma in 31%, tubulo-villous adenoma in 27%, villous adenoma in 42%, high-grade dysplasia in 38%, in situ carcinoma in 19% of the cases and mucosal carcinoma (m2) in 8% of the cases. The two cases (7.7%) of procedural bleeding that occurred were managed endoscopically and one small perforation was treated with clips. During follow-up, recurrence of the tumor occurred in three patients (12%), three of whom received endoscopic treatment.

CONCLUSION: EMR for tumors larger than 4 cm is a safe and effective procedure that could compete with endoscopic submucosal dissection, despite providing incomplete histological assessment.

Large refractory colonic polyps: is it time to change our practice? A prospective study of the clinical and economic impact of a tertiary referral colonic mucosal resection and polypectomy service (with videos)

BACKGROUND

Patients who have large, difficult, colorectal lesions not readily amenable to endoscopic resection are often referred directly to surgery. The application of advanced polypectomy and endoscopic mucosal resection (EMR) techniques undertaken by a tertiary referral colonic mucosal resection and polypectomy service (TRCPS) is not often considered but may be superior to surgery.

OBJECTIVE

To evaluate the safety, efficacy, and cost savings of a TRCPS for colorectal lesions.

DESIGN

Prospective intention-to-treat analysis.

SETTING

Tertiary academic referral center.

PATIENTS

In a 21-month period ending in April 2008, consecutive patients with large or complex colorectal polyps referred by other specialist endoscopists were prospectively enrolled on an intention-to-treat basis.

INTERVENTION

For sessile lesions, a standardized EMR approach was used. Pedunculated lesions were removed with or without pretreatment with an Endoloop procedure.

MAIN OUTCOME MEASUREMENTS

Complete resection, complications, recurrence, and potential cost savings comparing actual outcome of the cohort with a hypothetical analysis of surgical management.

RESULTS

This study included 174 patients (mean age 68 years) who were referred with 193 difficult polyps (186 laterally spreading, mean size 30 mm [range 10-80 mm]). We totally excised 173 laterally spreading lesions by EMR (115 piecemeal, 58 en bloc). Invasive adenocarcinoma was found in 6 lesions-5 treated successfully with EMR. Eleven patients were referred directly to surgery without an endoscopic attempt due to suspected invasive carcinoma. Seven >30-mm, pedunculated polyps were removed. There were no perforations. A total of 20 bed days was used because of endoscopic complications. Among all patients referred, 90% avoided the need for surgery. Excluding patients who were treated surgically for invasive cancer, the procedural success was 95% (157 of 168). By using Australian cost estimates applied to the entire group and compared with cost estimates assuming all patients had undergone surgery, we calculated the total medical cost savings was $6990 (U.S.) per patient, or a total savings of $1,216,231 (U.S.).

LIMITATION

Not a randomized trial.

CONCLUSIONS

Colonoscopic polypectomy performed by a TRCPS on large or difficult polyps is technically effective and safe. This approach results in major cost savings and avoids the potential complications of colonic surgery. This type of clinical pathway should be developed to enhance patient outcomes and reduce health care costs.

Clinicopathologic features and endoscopic mucosal resection of laterally spreading tumors: experience from China

BACKGROUND

Laterally spreading tumors (LSTs) are being increasingly reported nowadays in Japan and the western countries with the application of magnification chromoendoscopy. The aim of this study was to analyze the clinicopathologic features of LSTs and to assess the outcome and safety of endoscopic mucosal resection (EMR) in China.

PATIENTS AND METHODS

One hundred nine patients with LSTs who underwent magnification chromoendoscopy were studied retrospectively. Clinicopathological features of 111 LSTs were analyzed. The efficacy and safety of EMR was assessed in 79 LSTs based on the outcome of follow-up colonoscopy and resection-related complications.

RESULTS

A total of 111 LSTs were diagnosed in 109 patients, including 89 (80%) laterally spreading tumor-granular (LST-G) type and 22 (20%) laterally spreading tumor-non-granular (LST-NG) type. There was significant difference in the dominant pit pattern between LST-G type and LST-NG type (p < 0.001). Type IV pit pattern (62%) was the main crypt pattern in LST-G type; whereas, type IIIL (50%) and type V pit pattern (36%) were predominant crypt patterns in LST-NG type. EMR was performed for 103 lesions. Six of the nine lesions with type V(I) pit pattern were completely resected by EMR. Eleven (14%) local recurrent lesions were detected in 79 follow-up lesions and were treated successfully during the follow-up.

CONCLUSIONS

The type of dominant pit pattern was different between LST-G type and LST-NG type. Many LSTs with a type V(I) pit pattern can be completely resected by EMR. EMR technique is a safe and efficacious treatment method for LST.

Endoscopic mucosal resection for treatment of colorectal polyps occurring in the senium and presenium: a report of 561 cases

AIM: To investigate the efficacy of endoscopic mucosal resection (EMR) for colorectal polyps occurring in the senium and presenium, and analyze the clinical and pathological features of resected lesions as well as the indications for and the complications of EMR.

METHODS: A total of 513 patients with 766 lesions were included in this study. The "inject and cut]EMR technique was used. The resected lesions were observed pathohistologically. The patients were followed up for a period of 1 to 60 months to evaluate the efficacy of EMR. Intraoperative and postoperative complications and treatments were recorded.

RESULTS: A cure rate of 96.3% was achieved by EMR. Twenty-one patients (2.7%) were referred for surgery because of invasive cancer revealed by pathological examination after EMR. Bleeding occurred in 23 patients (4.2%) during EMR procedures, all of which underwent successful endoscopic hemostasis. Delayed bleeding occurred in ten patients (1.8%), of which seven underwent successful endoscopic hemostasis, and three received blood transfusion and conservative medical management. No perforation, infection and other complications occurred. The incidences of inflammatory polyps, hyperplastic polyps, adenomatous polyps and cancerous adenoma were 29.0%, 21.1%, 45.7% and 4.2%, respectively. The incidence of adenomatous polyps increased gradually with age. No recurrence was found during the follow-up period.

CONCLUSION: EMR is safe, minimally invasive, and more effective than traditional endoscopic approach in the treatment of colorectal polyps.

Treatment strategy for laterally spreading tumors in Japan: before and after the introduction of endoscopic submucosal dissection

BACKGROUND AND AIMS

Laterally spreading tumors (LST) in the colorectum are considered good candidates for endoscopic resection (ER). Because LST-non-granular (NG) tumors show multifocal invasion into the submucosal layer, en bloc resection is necessary for adequate histopathological evaluation. Therefore, surgical resection has been recommended when a lesion is suspected to be an invasive cancer and too large to resect en bloc. The aim of the present study was to evaluate whether the introduction of colorectal ESD, which was developed for en bloc resection of early gastric cancers, could improve the en bloc resection rate of large LST-NG-type tumors and reduce the surgical resection rate.

METHODS

Between January 1999 and December 2005, a total of 166 LST-NG-type tumors measuring > or = 20 mm in 161 patients were included in this study. The en bloc resection rate and the surgical resection rate were historically compared between two periods, before and after the introduction of ESD.

RESULTS

The en bloc resection rate for ER lesions was significantly higher in the latter period (35.0% [14/40]vs 76.5% [75/98]; P < 0.001), and the rate of surgery for adenomas and intramucosal or sm minute cancers was significantly lower in the latter period (20.0% [10/50]vs 1.1% [1/89]; P < 0.001).

CONCLUSIONS

The introduction of colonic ESD was able to change our treatment strategy for LST, improving the en bloc resection rate and reducing the surgical resection rate.

Current status of colonic endoscopic mucosal resection in the west and the interface with endoscopic submucosal dissection

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

Colonoscopic polypectomy in anticoagulated patients

AIM: To review our experience performing polypectomy in anticoagulated patients without interruption of anticoagulation.

METHODS: Retrospective chart review at the Veterans Affairs Palo Alto Health Care System. Two hundred and twenty five polypectomies were performed in 123 patients. Patients followed a standardized protocol that included stopping warfarin for 36 h to avoid supratherapeutic anticoagulation from the bowel preparation. Patients with lesions larger than 1 cm were generally rescheduled for polypectomy off warfarin. Endoscopic clips were routinely applied prophylactically.

RESULTS: One patient (0.8%, 95% CI: 0.1%-4.5%) developed major post-polypectomy bleeding that required transfusion. Two others (1.6%, 95% CI: 0.5%-5.7%) had self-limited hematochezia at home and did not seek medical attention. The average polyp size was 5.1 ± 2.2 mm.

CONCLUSION: Polypectomy can be performed in therapeutically anticoagulated patients with lesions up to 1 cm in size with an acceptable bleeding rate.

EMR of large, sessile, sporadic nonampullary duodenal adenomas: technical aspects and long-term outcome (with videos)

BACKGROUND

EMR is a viable alternative to surgery for removal of large mucosal neoplastic lesions of the entire GI tract. Few studies have, however, been published on the safety, efficacy, and technical aspects of EMR in the duodenum.

OBJECTIVE

Our purpose was to evaluate the efficacy and safety of EMR of large (>15 mm) duodenal adenomas.

DESIGN

Retrospective evaluation of a defined patient cohort.

SETTING

Tertiary academic referral center.

PATIENTS

Patients with large (>15 mm) sporadic nonampullary duodenal adenomas managed by a standardized technique who were referred by other specialist endoscopists for endoscopic treatment.

METHODS

Five-year data from patients undergoing EMR for large duodenal adenomas were reviewed retrospectively. Immediate and delayed complications were recorded.

RESULTS

Twenty-one lesions were removed by EMR in 23 patients (mean age 62.2 years, 13 female, 10 male). The mean size of lesions resected was 27.6 mm (median 20 mm, range 15-60 mm). Post-EMR histologic examination revealed mucosal adenocarcinoma in 1, low-grade tubulovillous adenoma (TVA) in 16, high- or focal high-grade TVA in 3 patients, and 1 with both high-grade TVA and carcinoid. EMR was performed successfully in 18 patients during a single session. Two patients required 2 sessions and 1 required 3 sessions for complete resection. The median follow-up was 13 months (range 4-44 months). During follow-up, 5 patients had minor residual adenomas that were treated successfully with snare resection and/or argon plasma coagulation. One patient had EMR site bleeding. There were no perforations.

LIMITATION

Retrospective study.

CONCLUSION

EMR for large sporadic nonampullary duodenal adenomas is a safe and effective technique.