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

Effectiveness and safety of the different endoscopic resection methods for 10- to 20-mm nonpedunculated colorectal polyps: A systematic review and pooled analysis

BACKGROUND

We performed a systematic review and pooled analysis to assess the effectiveness and safety of different endoscopic resection methods for 10- to 20-mm nonpedunculated colorectal polyps.

METHODS

Articles in PubMed, EMBASE, and the Cochrane Library related to the common endoscopic treatment of 10- to 20-mm nonpedunculated polyps published as of April 2020 were searched. Primary outcomes were the R0 resection rate and en bloc resection rate. Secondary outcomes were safety and the recurrence rate. Meta-regression and subgroup analysis were also performed.

RESULTS

A total of 36 studies involving 3212 polyps were included in the final analysis. Overall, the effectiveness of resection methods with a submucosal uplifting effect, including endoscopic mucosal resection (EMR), cold EMR and underwater EMR (UEMR), was better than that of methods without a nonsubmucosal uplifting effect [R0 resection rate, 90% (95% confidence interval (CI) 0.81-0.94, I² = 84%) vs 82% (95% CI 0.78-0.85, I² = 0%); en bloc resection rate 85% (95% CI 0.79-0.91, I² = 83%) vs 74% (95% CI 0.47-0.94, I² = 94%)]. Regarding safety, the pooled data showed that hot resection [hot snare polypectomy, UEMR and EMR] had a higher risk of intraprocedural bleeding than cold resection [3% (95% CI 0.01-0.05, I² = 68%) vs 0% (95% CI 0-0.01, I² = 0%)], while the incidences of delayed bleeding, perforation and post-polypectomy syndrome were all low.

CONCLUSIONS

Methods with submucosal uplifting effects are more effective than those without for resecting 10- to 20-mm nonpedunculated colorectal polyps, and cold EMR is associated with a lower risk of intraprocedural bleeding than other methods. Additional research is needed to verify the advantages of these methods, especially cold EMR.

Risk factors associated with clinical outcomes of endoscopic mucosal resection for colorectal laterally spreading tumors: A Honam Association for the Study of Intestinal Diseases (HASID) multicenter study

BACKGROUND/AIMS

Colorectal laterally spreading tumors (LSTs) are large and superficial neoplasms. Most are adenomatous lesions. Endoscopic mucosal resection (EMR) is a standard technique of removing precursor colorectal lesions. The aim of the present study was to assess the factors associated with the clinical outcomes of EMR for LSTs.

MATERIALS AND METHODS

A total of 275 patients with LSTs who underwent EMR were enrolled in the study. The clinical outcomes of the patients were analyzed by retrospectively reviewing their medical records.

RESULTS

The en bloc resection and R0 resection rates were 86.9% and 80.4%, respectively. The bleeding and perforation rates were 7.6% and 0.4%, respectively. The frequency of high-grade dysplasia and adenocarcinoma histology was significantly higher, and the procedure time was significantly longer in LSTs >20 mm than in those ≤20 mm. The R0 resection rate was significantly higher in LSTs ≤20 mm than in those >20 mm. The frequency of piecemeal resection was significantly higher in LSTs with an adenomatous and cancerous pit pattern than in those with a non-neoplastic pit pattern. The frequency of piecemeal resection was significantly higher in LSTs with adenocarcinoma than in those with low-grade dysplasia. Multivariate analysis revealed that adenomatous pit pattern, high-grade dysplasia, or adenocarcinoma was a significant independent risk factor of LSTs for piecemeal resection after EMR.

CONCLUSION

EMR is useful for treating ≤20 mm LSTs with regard to curative resection and procedure time. LSTs with an adenomatous pit pattern, high-grade dysplasia, or adenocarcinoma are significant independent risk factors for piecemeal resection after EMR.

Management of colorectal laterally spreading tumors: a systematic review and meta-analysis

Objective and study aims  To evaluate the efficacy and safety of different endoscopic resection techniques for laterally spreading colorectal tumors (LST). Methods  Relevant studies were identified in three electronic databases (PubMed, ISI and Cochrane Central Register). We considered all clinical studies in which colorectal LST were treated with endoscopic resection (endoscopic mucosal resection [EMR] and/or endoscopic submucosal dissection [ESD]) and/or transanal minimally invasive surgery (TEMS). Rates of en-bloc/piecemeal resection, complete endoscopic resection, R0 resection, curative resection, adverse events (AEs) or recurrence, were extracted. Study quality was assessed with the Newcastle-Ottawa Scale and a meta-analysis was performed using a random-effects model. Results  Forty-nine studies were included. Complete resection was similar between techniques (EMR 99.5 % [95 % CI 98.6 %-100 %] vs. ESD 97.9 % [95 % CI 96.1 - 99.2 %]), being curative in 1685/1895 (13 studies, pooled curative resection 90 %, 95 % CI 86.6 - 92.9 %, I ²  = 79 %) with non-significantly higher curative resection rates with ESD (93.6 %, 95 % CI 91.3 - 95.5 %, vs. 84 % 95 % CI 78.1 - 89.3 % with EMR). ESD was also associated with a significantly higher perforation risk (pooled incidence 5.9 %, 95 % CI 4.3 - 7.9 %, vs. EMR 1.2 %, 95 % CI 0.5 - 2.3 %) while bleeding was significantly more frequent with EMR (9.6 %, 95 % CI 6.5 - 13.2 %; vs. ESD 2.8 %, 95 % CI 1.9 - 4.0 %). Procedure-related mortality was 0.1 %. Recurrence occurred in 5.5 %, more often with EMR (12.6 %, 95 % CI 9.1 - 16.6 % vs. ESD 1.1 %, 95 % CI 0.3 - 2.5 %), with most amenable to successful endoscopic treatment (87.7 %, 95 % CI 81.1 - 93.1 %). Surgery was limited to 2.7 % of the lesions, 0.5 % due to AEs. No data of TEMS were available for LST. Conclusions  EMR and ESD are both effective and safe and are associated with a very low risk of procedure related mortality.

Clinical outcomes of endoscopic resection for colorectal laterally spreading tumors with advanced histology

BACKGROUND

Colorectal laterally spreading tumors (LSTs) are large, flat neoplasms that are usually treated using different endoscopic techniques based on their morphology, size, and histology. The aim of this study was to evaluate the clinical outcomes of LSTs with advanced histology treated by endoscopic resection.

METHODS

A total of 246 LSTs with advanced histology [i.e., high-grade dysplasia (HGD) and adenocarcinoma (AC)] treated by endoscopic resection [i.e., endoscopic mucosal resection (EMR), EMR-precutting (EMR-P), and endoscopic submucosal dissection (ESD)] were enrolled. Clinicopathological characteristics were collected by review of patient's medical records.

RESULTS

The en bloc resection and R0 resection rates were 75.6% and 85.0%, respectively. The bleeding and perforation rates were 10.2% and 2.4%, respectively. The frequency of cancerous pit pattern and bleeding was significantly higher in LSTs with AC than in LSTs with HGD. The R0 resection rate in LSTs with HGD was significantly higher than that in LSTs with AC. The frequency of cancerous pit patterns in LST cases with submucosal AC was significantly higher than those with intramucosal AC. The mean size of the LSTs was significantly larger in ESD group than in EMR or EMR-P groups. The frequencies of nodular mixed subtype, cancerous pit patterns, and en bloc resection rates were significantly higher in the ESD group than in the EMR or EMR-P groups. However, the frequency of perforation was significantly higher in EMR-P group than in EMR or ESD groups.

CONCLUSIONS

These results indicate that ESD is a more acceptable treatment approach for resection of colorectal LSTs of larger size, with nodular mixed subtype, having a cancerous pit pattern or AC, using either en bloc or curative resection methods, compared to EMR or EMR-P procedures.

Clinicopathological feature and treatment outcome of patients with colorectal laterally spreading tumors treated by endoscopic submucosal dissection

BACKGROUND/AIMS

Endoscopic submucosal dissection (ESD) is an advanced technique that can be used to treat precancerous and early colorectal neoplasms by facilitating en bloc resection regardless of tumor size. In our study, we investigated the clinicopathological feature and the treatment outcome of patients with colorectal laterally spreading tumors (LSTs) that were treated by ESD.

METHODS

The study enrolled all of 210 patients with colorectal LSTs who underwent ESD. Clinical outcomes were analyzed by retrospectively reviewing medical records.

RESULTS

A cancerous pit pattern (Vi/Vn) was more common in pseudo-depressed (PD) subtype than in flat elevated (FE) subtype. The incidence of adenocarcinoma in the PD subtype and nodular mixed (NM) subtypes was significantly higher than in the homogenous (HG) subtype and FE subtype. The en bloc and R0 resection rates were 89.0% and 85.7%, respectively. The bleeding and perforation rates were 5.2% and 1.9%, respectively. The mean procedure time was much longer in the PD subtype than in the FE subtype. The en bloc resection rate was significantly higher in the NM subtype than in the HG subtype. However, there were no statistically significant differences in mean procedure time, en bloc resection rate, R0 resection rate, bleeding rate, or perforation rate between LST-granular and LST-nongranular types.

CONCLUSIONS

These results indicate that ESD is acceptable for treating colorectal LSTs concerning en bloc resection, curative resection, and risk of complications. Careful consideration is required for complete resection of the PD subtype and NM subtype because of their higher malignant potential.

Risk factors for procedure-related complications after endoscopic resection of colorectal laterally spreading tumors

Colorectal laterally spreading tumors (LSTs) are large and flat elevated neoplasms with diameters of at least 10 mm. Endoscopic resection of LSTs, with their large size and broad base, is difficult and dangerous compared with the resection of polypoid neoplasms. This study aimed to determine the risk factors for procedure-related complications including bleeding and perforation after endoscopic resection of LSTs.Patients with colorectal LST undergoing endoscopic resection at 5 university hospitals in Honam Province of South Korea were enrolled, and their records about patients, lesions, and procedure parameters associated with the occurrence of complications were reviewed retrospectively. Logistic regression analysis was performed to identify risk factors for complications.The frequency of comorbidities in bleeding group was significantly higher than in the no bleeding group. The frequency of bleeding was significantly higher in lesions with adenocarcinoma than in lesions with low or high-grade dysplasia. The frequency of bleeding was significantly higher in piecemeal resection than in en bloc resection. The frequency of perforation was significantly higher in endoscopic mucosal resection-precutting (EMR-P) than in endoscopic mucosal resection (EMR) or endoscopic submucosal dissection. The mean procedure duration was significantly longer in the perforation group than in the no perforation group. On multivariate analysis, patient comorbidity and histologic grade of the lesion were significant independent risk factors for bleeding, whereas EMR-P was a significant independent risk factor for perforation after endoscopic resection.This study demonstrated that patient comorbidity and histologic grade of lesion were significant independent risk factors for bleeding, and EMR-P was a significant independent risk factor for perforation after endoscopic resection of colorectal LSTs.

Clinicopathological features of laterally spreading colorectal tumors and their association with advanced histology and invasiveness: An experience from Honam province of South Korea: A Honam Association for the Study of Intestinal Diseases (HASID)

Background and aims

Laterally spreading colorectal tumors (LSTs) are divided into four subtypes, including homogenous (HG), nodular mixed (NM), flat elevated (FE), and pseudo-depressed (PD), based on their different endoscopic morphologies. The aim of this study was to investigate the clinicopathological significance of LST subtypes and their association with advanced histology.

Methods

We investigated the medical records of consecutive patients with LST who initially underwent endoscopic resection at five university hospitals in Honam province of South Korea between January 2012 and December 2013. A total of 566LST lesions removed via endoscopic procedures were collected retrospectively for data analysis.

Results

The PD, FE, and NM subtypes were more common in the distal colon and the HG subtype in the proximal colon. The PD subtype had the biggest tumor size, followed by the NM subtype. The frequency of adenomatous pit pattern was significantly higher in the HG, NM, and FE subtypes than in the PD subtype. In contrast, the frequency of cancerous pit pattern was significantly higher in the PD subtype than in the other three subtypes. The rate of advanced histology (high-grade dysplasia or carcinoma) among the LSTs was 36.0%. The risk of advanced histology increased in the distal colon compared with the proximal colon. The PD subtype had the highest incidence of villous component, advanced histology,submucosal invasion, and postprocedure perforation among the four subtypes. The distal colon as tumor site, larger tumor size, PD subtype, and villous component were associated with a statistically significant increased risk of advanced histology.

Conclusion

Our results indicate that the location, size, endoscopic subtype, and histologic component of the LSTs are associated with an increased risk of advanced histology. Therefore, these clinicopathological parameters may be useful in selecting therapeutic strategies in the clinical setting.

Endoscopic mucosal resection and endoscopic submucosal dissection for colorectal lesions: A systematic review

AIM

To assess the efficacy and safety of endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) for the treatment of colorectal lesions.

METHODS

A literature search was conducted from January 2000 to May 2015. The main outcomes were: recurrence after "en bloc" and "piecemeal" resection; procedure related adverse events; the EMR endoscopic success rate and the completely eradicated resection rate (R0) after ESD.

RESULTS

A total of 66 studies were included in the analysis. The total number of lesions was 17950 (EMR: 11.873; ESD: 6077). Recurrence rate was higher in the EMR than ESD group (765/7303l vs. 50/3910 OR 8.19, 95% CI 6.2-10.9 p<0.0001). EMR-en bloc resection was achieved in 6793/10803 lesions (62.8%) while ESD-en bloc resection was obtained in 5500/6077 lesions (90.5%) (OR 0.18, p<0.0001, 95% CI 0.16-0.2). Perforation occurred more frequently in ESD than in EMR group (p<0.0001, OR 0.19, 95% CI 0.15-0.24).

CONCLUSIONS

Endoscopic resection of large colorectal lesions is safe and effective. Compared with EMR, ESD results in higher "en bloc" resection rate and lower local recurrence rate, however ESD has high procedure-related complication rates.

Optimizing post-polypectomy surveillance: A practical guide for the endoscopist

Several gastrointestinal societies strongly recommend colonoscopy surveillance after endoscopic and surgical resection of colorectal neoplasms. Common denominators to these recommendations include: high-quality baseline colonoscopy before inclusion in a surveillance program; risk stratification based on clinicopathological profiles to guide surveillance intervals; and endoscopist responsibility for providing surveillance advice. Considerable variability also exists between guidelines (i.e. regarding risk classification and surveillance intervals). In this review, we examine key factors for quality of post-polypectomy surveillance practice, in particular bowel preparation, endoscopic findings at baseline examination and adherence to surveillance recommendations. Frequently asked questions by the practising endoscopist are addressed.

A long-term follow-up study on the prognosis of endoscopic submucosal dissection for colorectal laterally spreading tumors

BACKGROUND AND AIMS

Colorectal laterally spreading tumors (LSTs) are divided into homogeneous (LST-G-H), nodular mixed (LST-G-M), flat elevated (LST-NG-F), and pseudodepressed (LST-NG-PD) subtypes. We hypothesized that based on the rates of advanced histology, the recurrence rates of the LST-NG-PD and LST-G-M groups may be higher than those of the other subgroups.

METHODS

Endoscopic submucosal dissection (ESD) was performed in 156 patients with a total of 177 LSTs. The clinicopathological features and long-term prognosis of ESD according to specific subtype were investigated.

RESULTS

LSTs were most commonly found in the rectum, and the highest percentage of rectal lesions was observed in the LST-G-M group (71.1% vs overall 55.4%, P = .032). The LST-G-M lesions were larger (60 ± 22 mm vs 40 ± 33 mm, P = .034) than the LST-G-H lesions. The LST-G-M group also demonstrated more high-grade intraepithelial neoplasias (32.2% vs 10.8%, P = .003) and submucosal carcinomas (13.6% vs 1.5%, P = .010) compared with the LST-G-H group. The LST-NG-PD group exhibited the highest incidence of submucosally invasive cancer (16.7%). The overall perforation rate was 2.3%. The perforation rate in the LST-NG group was higher than that in the LST-G group (5.7% vs 0.8%, P = .047). All recurrences (7.7%) were found by colonoscopy without any detection of cancers, and no difference was found among the subtypes.

CONCLUSIONS

No significant differences were observed among subgroups with 44.4 ± 16.3 months of follow-up. Considering that all recurrences were discovered by colonoscopy and most could be cured by repeated ESD, the LSTs of all subgroups require more intensive follow-up compared with smaller adenomatous lesions.

Large Colorectal Lesions: Evaluation and Management

In the last years, a distinctive interest has been raised on large polypoid and non-polypoid colorectal tumors, and specially on flat neoplastic lesions ≥20 mm tending to grow laterally, the so called laterally spreading tumors (LST). Real or virtual chromoendoscopy, endoscopic ultrasound or magnetic resonance should be considered for the estimation of submucosal invasion of these neoplasms. Lesions suitable for endoscopic resection are those confined to the mucosa or selected cases with submucosal invasion ≤1000 μm. Polypectomy or endoscopic mucosal resection remain a first-line therapy for large colorectal neoplasms, whereas endoscopic submucosal dissection in high-volume centers or surgery should be considered for large LSTs for which en bloc resection is mandatory.

Does magnifying narrow-band imaging or magnifying chromoendoscopy help experienced endoscopists assess invasion depth of large sessile and flat polyps?

BACKGROUND

Distinguishing deep submucosa (SM) from superficial SM cancer in large sessile and flat colorectal polyps (>2 cm) is crucial in making the most appropriate therapeutic decision. We evaluated the additional role of magnifying narrow-band imaging (NBI) and magnifying chromoendoscopy (MCE) in assessing the depth of invasion in large sessile and flat polyps in comparison to morphological evaluation performed by experienced endoscopists.

METHODS

From May 2011 to December 2011, a total of 85 large sessile and flat polyps were analyzed. Endoscopic features of the polyps were independently evaluated by experienced endoscopists. Subsequently, the polyps were observed using magnifying NBI and MCE.

RESULTS

A total of 58 intramucosal lesions and 27 SM cancers (five superficial and 22 deep) were identified. The diagnostic accuracy of the experienced endoscopists, NBI, and MCE were 92.9, 90.6, and 89.4 %, respectively, for deep SM cancer. In combination with NBI or MCE, the diagnostic accuracy of the experienced endoscopists did not change significantly for deep SM cancer, with an accuracy of 95.3 % for both NBI and MCE.

CONCLUSIONS

Conventional colonoscopy can differentiate superficial from deep SM cancers with an accuracy of as high as 92.9 % in large sessile and flat polyps. Further diagnostic strategies are required in order to precisely assess the depth of invasion, especially in large colorectal polyps.

Consensus on the Prevention, Screening, Early Diagnosis and Treatment of Colorectal Tumors in China: Chinese Society of Gastroenterology, October 14-15, 2011, Shanghai, China

BACKGROUND

Colorectal cancer (CRC) is steadily increasing in China. Colorectal adenoma (CRA) is the most important precancerous disease of CRC. Screening for colorectal tumors can aid early diagnosis. Advances in endoscopic mucosal resection and endoscopic submucosal dissection can aid the early treatment of colorectal tumors. Furthermore, because of high risk of recurrence after removal of adenomas under endoscopy, factors contributing to recurrence, the follow-up mode and the interval established, and the feasibility of application and the time of various chemical preventions should be concerned. However, a relevant consensus on the screening, early diagnosis and treatment, and prevention of colorectal tumors in China is lacking.

SUMMARY

The consensus recommendations include epidemiology, pathology, screening, early diagnosis, endoscopic treatment, monitoring and follow-up, and chemoprevention of colorectal tumors in China.

KEY MESSAGE

This is the first consensus on the prevention, screening, early diagnosis and treatment of CRA and CRC in China based on evidence in the literature and on local data.

PRACTICAL IMPLICATIONS

Through reviewing the literature, regional data and passing the consensus by an anonymous vote, gastroenterology experts from all over China launch the consensus recommendations in Shanghai. The incidence and mortality of CRC in China has increased, and the incidence or detection rate of CRA has increased rapidly. Screening for colorectal tumors should be performed at age 50-74 years. Preliminary screening should be undertaken to find persons at high risk, followed by colonoscopy. A screening cycle of 3 years is recommended for persistent interventions. Opportunistic screening is a mode suitable for the current healthcare system and national situation. Colonoscopy combined with pathological examination is the standard method for the diagnosis of colorectal tumors. CRA removal under endoscopy can prevent CRC to some extent, but CRA has an obvious recurrence trend. The follow-up interval after the removal or surgery of colorectal tumors should be different with lesions. Primary prevention of CRA includes improved diet with more fiber, supplements containing calcium and vitamin D, supplements containing folic acid for those with low hemoglobin levels, and cessation of tobacco smoking. Non-steroidal anti-inflammatory drugs and selective cyclooxygenase-2 inhibitors have been recognized to prevent recurrence after adenoma removal.

Laterally spreading tumors of the colorectum: clinicopathologic features and malignant potential by macroscopic morphology

BACKGROUND/AIMS

Laterally spreading tumors (LSTs) are being increasingly reported nowadays. The aims of this study were to analyze the clinicopathologic characteristics and to identify the risk factors of malignancy in patients with LSTs by morphological subclassification.

PATIENTS AND METHODS

The authors retrospectively reviewed 326 LSTs (287 patients). Patient characteristics, endoscopic findings, and histologic findings were analyzed. Endoscopic findings were subdivided into homogeneous, mixed nodular, flat elevated, and pseudo-depressed subtypes. The clinicopathological features of these subtypes were compared.

RESULTS

Of the 287 patients treated, 173 (50.3 %) were male and overall mean patient age was 65 ± 10 years (ranged 35 to 83 year). Of the 326 LSTs diagnosed, 116 (35.6 %) were homogeneous and 102 (31.3 %) were flat elevated subtype. The location was significantly different among morphological subtype. Tumors of the mixed nodular subtype were significantly larger than the tumors of the other three subtypes (p = 0.00). Of the 326 lesions, 279 underwent endoscopic mucosal resection (granular type 88.1 % (177/201)/nongranular type 81.6 % (102/125)). Two hundred forty-nine lesions (76.4 %) were resected en bloc, and 45 lesions (13.8 %) were resected using the piecemeal technique. Piecemeal resection was significantly more common for the pseudo-depressed subtype (27.0 %, p = 0.00). The overall malignancy rate on a lesion basis was 8.6 %. The malignancy rate increased with lesion size and was higher for the pseudo-depressed (24.3 %) and the mixed nodular subtype (14.1 %). Submucosal invasion was noted for 16 % of pseudo-depressed lesions, and this was significantly higher than the invasion rates of the other subtypes (p = 0.06). By multivariate analysis, morphologic subtype, especially the pseudo-depressed or mixed nodular subtype and size larger than 20 mm were risk factor of malignancy.

CONCLUSIONS

The clinicopathological features of laterally spreading tumors differ with respect to macroscopic morphology, and the risk of malignant transformation is significantly higher for the mixed nodular or pseudo-depressed subtypes and lesion larger than 20 mm. Careful consideration is required when choosing a treatment modality, and lesions of the mixed nodular and pseudo-depressed subtypes should be completely removed.

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.

Laterally spreading tumors in the colon and rectum

The large and relatively flat colorectal neoplastic lesions called laterally spreading tumors are classified as nonpolypoid despite some mixed patterns with protruding nodules. Large hyperplastic polyps and sessile serrated lesions are non-neoplastic lesions that also have this morphology and may potentially progress to neoplasia. All these large and relatively flat lesions are more frequent in the proximal colon and less conspicuous than polypoid lesions. Their underdiagnosis is a major factor in the failure of colonoscopy to prevent cancer in the proximal colon. The treatment of laterally spreading tumors by endoscopic resection (endoscopic mucosal resection, piecemeal endoscopic mucosal resection, endoscopic submucosal dissection), or by surgery is based on a careful morphologic analysis, taking into account the size and surface with nodules or depression. The technique of endoscopic submucosal dissection should be diffused because it reduces the number of surgical indications.

Endoscopic mucosal resection of giant laterally spreading tumors with submucosal injection of hydroxyethyl starch: comparative study with normal saline solution

BACKGROUND

Normal saline (NS) plus epinephrine (E) is the traditionally used solution as submucosal fluid cushion for a safe and effective endoscopic mucosal resection (EMR) of sessile colorectal polyps. It was hypothesized that hydroxyethyl starch (HES), an inexpensive and easily available solution might be an ideal solution for prolonged elevation of submucosal cushion for an easy and safe EMR of giant colorectal lateral spreading tumors (LSTs).

PATIENTS AND METHODS

During a 6-year period, patients suffering from colorectal LSTs with a diameter of ≥ 30 mm were randomized to undergo EMR by using either HES+E (group A) or NS+E (group B) for submucosal fluid cushion. All patients who had undergone a colonoscopy set the diagnosis of LSTs. The LSTs were examined with standard white light and narrow-band imaging to accurately delinate their margins before resection. The initial volume of injected solution, the additional amount to maintain the submucosal cushion, the duration of submucosal elevation and post-EMR-related complications were recorded. After EMR, patients had a standard follow-up at 3, 6, and 12 months and further if it was necessary using total colonoscopy.

RESULTS

Forty-nine patients suffering from giant LSTs were included in the study. No difference between the 2 groups was observed in patients' characteristics, size of LSTs, and the initial volume of injected solution. However, the additional amount of solution to maintain submucosal elevation was lower in group A (median, 4 mL; range, 2 to 25) than in group B (median, 6 mL; range, 3 to 8; P=0.001). Moreover, submucosal elevation had a statistically longer duration in group A (median, 18.5 min; range, 14.5 to 28.4) than in group B (median, 20.15 min, range, 9.6 to 13.4; P<0.001), and there was a statistical difference on total procedure time in favor of group A [group A, 20.15 min (12 to 32.5) vs. group B, 22.8 min (18 to 34.5)]. One case of macroperforation, 2 cases of postpolypectomy syndrome, and 1 case of EMR-related bleeding were observed in the HES+E group, whereas 6 cases of EMR-related bleeding were observed in the NS+E group. During a median follow-up of 32 and 34 months, for HES+E and NS+E groups, respectively, 5 and 7 recurrences were observed, which were all treated endoscopically.

CONCLUSIONS

HES+E injection produces a more prolonged submucosal elevation and lowers total procedure time than NS+E; however, the safety of EMR is not influenced.

New closure technique for large mucosal defects after endoscopic submucosal dissection of colorectal tumors (with video)

BACKGROUND

Certain large colorectal tumors satisfy expanded indications for endoscopic submucosal dissection (ESD); however, the resulting large mucosal defects may contribute to complications such as delayed bleeding and perforation. Various closure devices and methods have been developed for large mucosal defects to prevent such complications.

OBJECTIVE

To demonstrate the feasibility of a new and simple technique for closing large mucosal defects after colorectal ESD.

DESIGN

Pilot feasibility study.

SETTING

Single center.

PATIENTS

Ten patients with 10 tumors half circumferential or less in size with sufficient muscle layer exposure after ESD were selected and treated by using the closure technique between July 2009 and June 2010.

INTERVENTION

Small mucosal incisions were made around the mucosal defect by the same needle-knife used during ESD. These incisions provided a better grip for conventional clips, which then facilitated lifting the surrounding mucosa across the defect without slipping, thereby making it considerably easier to reduce the size of the defect and place additional clips.

MAIN OUTCOME MEASUREMENTS

Patient characteristics and tumor clinicopathologic features were assessed as well as closure completion rate, closure procedure time, and closure-related complications.

RESULTS

All 10 tumors were successfully treated by ESD. Mean lesion size was 26.8 mm (range 8-50 mm). All mucosal defects were completely closed by using the new closure technique, without complications. Mean closure procedure time was 15 minutes (range 8-35 minutes).

LIMITATIONS

Small sample size with specifically selected patients.

CONCLUSION

Large mucosal defects resulting from colorectal ESD can be completely closed with small mucosal incisions by using conventional clips.

Endoscopic colorectal imaging and therapy

PURPOSE OF REVIEW

Colorectal cancer screening and prevention is a pivotal element in every gastroenterologist practice. Recent advances in imaging technology and treatment opened the field for endoscopic management of large flat colorectal polyps and early cancer.

RECENT FINDINGS

High-definition white light colonoscopy allowed for better characterization of colon polyps, particularly flat lesions. Chromoendoscopy facilitated the identification of colon polyps as well as better endoscopic polyp characterization, with strong correlation with final pathological diagnosis, opening the field of 'virtual' biopsy. One particular technology, confocal endomicroscopy can magnify an image approximately 1000 times resembling optical microscopy with very good correlation with histology. Endoscopic mucosal resection has gained great acceptance to manage flat colorectal polyps with the two major complications being bleeding and perforation, both now under 5% in experienced hands. Endoscopic submucosal resection was developed to increase en-bloc resection (less residual disease) of a flat colorectal lesion but one has to accept a higher perforation rate around 10%.

SUMMARY

Current technology allows for better polyp identification and characterization, which can be managed endoscopically.