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

Histological prediction and choice of the best resection strategy in front of a colorectal lesion > 2 cm: prospective comparison of endoscopic characterization, non-targeted and targeted biopsies

BACKGROUND

Accurate endoscopic characterization of colorectal lesions is essential to predict histology and select the best treatment strategy but remains very difficult. Instead of the recommended endoscopic characterization, many gastroenterologists routinely perform biopsies of the lesion to propose endoscopic resection with or without R0 intent. The aim of this study was to determine which of endoscopic characterization or biopsies, either targeted (TB) or non-targeted (NTB), is the most effective to determine the best treatment strategy for colorectal neoplasia > 2 cm.

METHODS

We prospectively assessed the best strategy between endoscopic characterization and targeted or non-targeted biopsies, so that the proposed resection technique offered a level of quality of tumor resection adapted to the definitive histology of the lesion on R0-resected specimen.

RESULTS

84 patients with 88 lesions were included. "Adequate treatment" was proposed by endoscopic characterization in 52.3 to 70.5% of cases, "under treatment" in 2.3 to 9.1% and "over treatment" in 20.5 to 45.5%. Two severe events were recorded. "Adequate treatment" was proposed by TB and NTB in respectively 72.7 and 69.3% of cases, "under treatment" in respectively 27.3 and 30.7% and no case of "over treatment" was reported. TB and NTB were ineffective to evaluate the depth of invasion in the submucosa and to differentiate superficial invasive from deep invasive adenocarcinomas.

CONCLUSIONS

Biopsies-based strategies are unable to predict depth of cancer invasion and could be associated with a risk of under treatment of large colorectal lesions in near a third of the cases compared to only around 5% with endoscopic characterization. Endoscopic characterization could lead to over treatment, but mainly by endoscopic submucosal dissection with low morbidity. Characterization with the CONECCT classification could decrease the risk of under treatment and avoid surgeries for non-malignant colorectal lesions. Other endoscopic criteria should be determined to better characterize colorectal lesions and to improve the best adapted treatment for each lesion.

Endoscopic submucosal dissection for proximal colonic lesions: An effective therapeutic option

Background and study aims

Due to the greater risks of adverse events (AEs) and the lower rate of submucosal invasive cancer (SMIC), large proximal colonic polyps are frequently treated by piecemeal endoscopic mucosal resection (EMR) in the West. However, this implies the risk of surgery to radicalize non-curative endoscopic resection in case of early colorectal cancer (CRC). We evaluated procedure outcomes in patients undergoing ESD for proximal colonic lesions at risk of SMIC.

Patients and methods

All consecutive patients with lesions at risk of SMIC proximal to splenic flexure referred for ESD at a tertiary center were prospectively included from 2019 to 2021. En bloc, R0, and curative resection rates were primary outcomes, while length of hospitalization, AEs, need for surgery due to AEs, and recurrence rates were secondary outcomes.

Results

A total of 116 patients (mean age: 68.4±10.91 years; men: 69.8%) were included. En bloc, R0, and curative resection rates were 84.5%, 78.4%, and 72.4%, respectively. T1 adenocarcinoma was reported in 25% of lesions (29/116). Eleven patients (9.5%) underwent secondary surgery due to non-curative resections; residual disease was found in one patient. Most frequent AE was intra-procedural perforation (9.9%); no AE required surgery. Median follow-up was 36 months; three of 97 recurrences (3.1%) at 6 months and one of 85 recurrence (1.2%) at 36 months were reported, which were all endoscopically treated.

Conclusions

In expert hands, ESD is effective and safe for proximal colonic lesions at risk of SMIC for the favorable balance between risk of AEs and benefit of avoiding unnecessary surgery, even for early CRC.

Endoscopic submucosal dissection versus endoscopic mucosal resection for laterally spreading rectal tumours

AIM

Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) are the two main techniques used for endoscopic resection of superficial rectal tumours. The aim of this study was to compare the outcomes of ESD and EMR in treating superficial rectal tumours.

METHOD

A retrospective observational study was conducted at two French centres including all patients treated with ESD or EMR for superficial rectal tumours. The primary outcome was the rate of local recurrence at the first follow-up endoscopy after endoscopic resection. Secondary outcomes included the curative resection rate, procedure duration, length of hospital stay, complication rates and the need for additional surgery.

RESULTS

A total of 254 patients were included, 159 treated with ESD and 95 treated with EMR. The local recurrence rate at the first follow-up endoscopy was 8.6% and was significantly lower in the ESD group than in the EMR group (4.3% vs. 16.9%; p = 0.005). The rates of en bloc and histologically complete resections were higher in the ESD group (88.1% vs. 42.7% and 85.5% vs. 38.9%, respectively; p < 0.001), while the curative resection rate was 90.6% in the EMR group and 92.5% in the ESD group (p = 0.59). Mostly due to poor histoprognostical criteria, 6.0% of patients underwent additional surgery (6.3% vs. 5.2% in the ESD vs. EMR group, respectively; p = 0.73).

CONCLUSION

ESD demonstrated higher rates of en bloc, R0 resection than EMR, translating into significantly lower rates of local recurrence at the first follow-up endoscopy.

Validation of a novel BCM model for recurrence risk prediction after mucosectomy of colorectal lateral spreading tumors in a European cohort

BACKGROUND AND AIM

Piecemeal endoscopic mucosal resection (pEMR) is the best approach to resect large lateral spreading tumors (LST, > 20 mm width). However, it is associated with early recurrence (ER) and late recurrence (LR). This study aims to assess the risk factors associated with ER and LR and to validate different predictive scores (SMSA, SERT, and BCM) in identifying the risk of ER and LR after LST resected by pEMR in a European cohort.

METHODS

Retrospective observational cohort study, based on a prospectively collected database, of large LST submitted to pEMR.

RESULTS

A total of 108 patients were included in the study and the incidence rates of ER and LR were 22 % and 8 %, respectively. The lesion's size, SERT, and BCM scores were independent predictor factors of ER (p-value < 0.05), while the lesion's site and BCM score were independent predictor factors of LR (p-value < 0.05). For the prediction of ER, the SERT score (cut-off > 1) presented the highest AUROC (0.758 vs 0.697 from BCM and 0.647 from SMSA). Regarding LR, the BCM model (cut-off > 2) presented the highest AUROC (0.817 vs 0.708 from SERT and 0.691 from SMSA).

CONCLUSIONS

We present the first external validation of the three scores mentioned in an European cohort. SERT and BCM scores had an acceptable performance in predicting ER and LR. However, the BCM model was the only score that proved to be an independent predictor of both ER and LR, proving to be valuable for both applications.

Cold Endoscopic Mucosal Resection (c-EMR) of Nonpedunculated Colorectal Polyps ≥20 mm: A Systematic Review and Meta-analysis

BACKGROUND

There is increasing evidence that cold endoscopic mucosal resection (c-EMR) can effectively treat large colorectal polyps. We aim to appraise the current literature and evaluate outcomes following c-EMR for nonpedunculated colonic polyps ≥20 mm.

METHODS

Major databases were searched. Primary outcomes included recurrence rate and adverse events. Meta-analysis was performed using a random-effects model.

RESULTS

Nine articles were included in the final analysis, which included 817 patients and 1077 colorectal polyps. Average polyp size was 28.8 (±5.1) mm. The pooled recurrence rate of polyps of any histology at 4 to 6 months was 21.0% (95% CI: 9.0%-32.0%, P <0.001, I2 =97.3, P <0.001). Subgroup analysis showed that recurrence was 10% for proximal lesions (95% CI: 0.0%-20.0%, P =0.054, I2 =93.7%, P =0.054) and 9% for distal lesions (95% CI: 2.0%-21.0%, P =0.114, I2 =95.8%, P =0.114). Furthermore, subgroup analysis showed that recurrence was 12% for adenoma (95% CI: 4.0%-19.0%, P =0.003, I2 =98.0%, P =0.003), and 3% for sessile serrated polyps (95% CI: 1.0%-5.0%, P =0.002, I2 =34.4%, P =0.002). Post-polypectomy bleeding occurred in 1% (n=8/817) of patients, whereas abdominal pain occurred in 0.2% (n=2/817) of patients.

CONCLUSIONS

C-EMR for nonpedunculated colorectal polyps ≥20 mm shows an excellent safety profile with a very low rate of delayed bleeding as well as significantly less recurrence for sessile serrated polyps than adenomas.

Approaches and considerations in the endoscopic treatment of T1 colorectal cancer

The detection of early colorectal cancer (CRC) is increasing through the implementation of screening programs. This increased detection enhances the likelihood of minimally invasive surgery and significantly lowers the risk of recurrence, thereby improving patient survival and reducing mortality rates. T1 CRC, the earliest stage, is treated endoscopically in cases with a low risk of lymph node metastasis (LNM). The advantages of endoscopic treatment compared with surgery include minimal invasiveness and limited tissue disruption, which reduce morbidity and mortality, preserve bowel function to avoid colectomy, accelerate recovery, and improve cost-effectiveness. However, T1 CRC has a risk of LNM. Thus, selection of the appropriate treatment between endoscopic treatment and surgery, while avoiding overtreatment, is challenging considering the potential for complete resection, LNM, and recurrence risk.

Learning curve for endoscopic submucosal dissection (ESD) in the United States: Large, untutored, single-operator experience

Background and study aims Endoscopic submucosal dissection (ESD) allows removal of tumors en-bloc. Western adoption of ESD has been hindered by its steep learning curve. Western data regarding ESD learning curve are limited. We analyzed the learning curve of a single endoscopist at a tertiary referral center in the United States. Patients and methods All consecutive ESDs performed by a single endoscopist at a tertiary referral center in the United States from 2015 through 2022 were identified. Descriptive statistics and CUSUM analysis were used to describe the learning curve for en-bloc, R0 resection, and resection speed. Results In our study, 503 patients with 515 lesions were included. Severe submucosal fibrosis was found in 17% of the lesions. The rates of en-bloc, R0, and curative resections were 81.9%, 71.1%, and 68.4%, respectively. CUSUM analysis showed that the learning curve plateaued at 268, 347, and 170 cases for en-bloc resection, R0 resection, and achieving a resection speed > 9 cm 2 /hr. Fibrosis significantly affected the R0 resection rate in the regression analysis (95% confidence interval 0.21-0.55). In colonic ESD curve analysis, the learning plateau was reached after 185 cases for both en-bloc and R0 resection. Conclusions Following ex-vivo training in an animal model, an untutored expert operator achieved competency in ESD between 250 and 350 procedures. Our data can inform development of future training programs in the West.

Endoscopic resection of large non-pedunculated colorectal polyps: current standards of treatment

Colorectal cancer is a significant public health concern, and large non-pedunculated colorectal polyps pose a substantial risk for malignancy and incomplete resection, which may lead to interval cancer. The choice of resection technique is influenced by various factors, including polyp size, morphology, location, submucosal invasion depth and endoscopist expertise. For non-cancerous superficial large non-pedunculated polyps, conventional hot or cold snare polypectomy, endoscopic mucosal resection and endoscopic submucosal dissection are common techniques for non-surgical therapeutic endoscopic resection of these polyps. This manuscript provides a comprehensive review of literature on current endoscopic resection techniques for large non-pedunculated colorectal polyps, emphasising indications, advantages, limitations and outcomes.

Curative Effect Analysis of Endoscopic Submucosal Dissection in Giant Laterally Spreading Rectal Tumors

GOAL

The objective of this study was to investigate the clinical efficacy of endoscopic submucosal dissection (ESD) in the treatment of giant lateral developing rectal-type tumors (laterally spreading tumors, LSTs).

BACKGROUND

There are no specialized studies on the efficacy of ESD in the treatment of LSTs measuring >5 cm in diameter, surgery was often used in the past, but it has the disadvantages of large trauma, many complications, and high cost.

METHODS

The data of 185 patients with rectal LSTs who had undergone ESD in the digestive endoscopy center of our hospital from January 2012 to June 2020 were retrospectively analyzed. Based on the size of the lesions, the patients were divided into 2 groups: diameter ≤5 cm (110 cases) and diameter >5 cm (75 cases), and we summarized and analyzed the en bloc resection rate, curative resection rate, procedure time, muscle injury, bleeding, perforation, postoperative stricture, and recurrence.

RESULTS

There was no difference in the en bloc resection rate and R0 resection rate between the 2 groups ( P =0.531). Moreover, there was no difference in the incidence of delayed perforation, postoperative stenosis, and recurrence, but the incidence of delayed bleeding was significantly higher in the giant LST group than the small LST group ( P =0.001). Moreover, for giant rectal LSTs, the growth pattern of the lesion, JNET classification, and the extent of postoperative mucosal defect do not significantly affect the efficacy of ESD. It is worth mentioning that the operation time was longer in the group with a diameter >5 cm, in which perforation was more frequent and the muscle layer was more likely to be injured during ESD ( P <0.001). The muscle injury during ESD was mainly related to the diameter of the lesion, the crossing the rectal pouch, and the operation time.

CONCLUSIONS

The use of ESD to treat giant rectal LSTs (>5 cm) is relatively difficult and can easily lead to intraoperative muscle injury, perforation, and late postoperative bleeding. However, if active intervention is performed, patients can still achieve good efficacy and prognosis, which can be applied in hospitals with certain conditions.

Safety and Efficacy of Powered Non-Thermal Endoscopic Resection Device for Removal of Colonic Polyps: A Systematic Review and Meta-Analysis

BACKGROUND

Endoscopic mucosal resection is a frequently employed method for removing colonic polyps. Nonetheless, the recurrence of these polyps over a healed submucosal base can complicate the extraction of leftover lesions through standard procedures. EndoRotor®, a non-thermal device specifically designed for endoscopic mucosal resection, has recently been assessed for its utility in removing colonic polyps, non-dysplastic Barrett's esophagus, and pancreatic necrosis. We conducted a systematic review and meta-analysis to ascertain the safety and efficacy of EndoRotor® in resecting scared or recurrence colonic polyps.

METHODS

We conducted an exhaustive review of existing literature using databases such as Medline, Embase, Web of Science, and the Cochrane Library until January 2023. Our aim was to find all studies that assessed the safety of non-thermal endoscopic resection devices in removing colonic polyps. The primary outcome we focused on was the rate of technical success. Secondary outcomes that we considered included the frequency of remaining lesions and instances of adverse events. To analyze these data, we used comprehensive meta-analysis software.

RESULTS

Our analysis incorporated three studies comprising 54 patients who underwent resection of 60 lesions. The combined technical success rate was 93.9% (95% confidence interval (CI): 77.7-98.6%, I2 = 25.5%). In patients who had another endoscopic examination, 20 were found to have a residual lesion. After the initial session, the combined rate of remaining lesions was 39.8% (95% CI: 15.3-70.8%, I2 = 74.5%). There were eight occurrences of intraoperative bleeding and four instances of bleeding post-procedure. The combined rate of intraoperative bleeding was 13.2% (95% CI: 6.7-24.3%, I2 = 0%), and post-procedure bleeding stood at 8.5% (95% CI: 3.4-19.8%, I2 = 0%). Only one major bleeding event was recorded, and no cases of perforation were reported.

CONCLUSION

Our research indicates that the EndoRotor® effectively removes scarred colonic polyps, though the rate of remaining lesions is significant, potentially necessitating several sessions for a thorough removal. There is a need for broader prospective studies, mainly randomized controlled trials, to further assess EndoRotor®'s efficiency and safety in eliminating colonic polyps.

pT1 colorectal cancer: A treatment dilemma

The implementation of population screening programs for colorectal cancer (CRC) has led to a considerable increase in the prevalence pT1-CRC originating on polyps amenable by local treatments. However, a high proportion of patients are referred for unnecessary oncological surgeries without a clear benefit in terms of survival. Selecting the appropriate endoscopic resection technique in the moment of diagnosis becomes crucial to provide the best treatment alternative to each individual polyp and patient. For this, it is imperative to increase the optical diagnostic skill for differentiating pT1-CRCs and decide the appropriate initial therapy. En bloc resection is crucial to obtain an adequate histological specimen that might allow organ preserving therapeutic management. In this review, we address key challenges in T1 CRC management, explore the efficacy and safety of the available diagnostic and therapeutic approaches, and shed light on upcoming advances in the field.

Treatment of adenoma recurrence after endoscopic mucosal resection

OBJECTIVE

Residual or recurrent adenoma (RRA) after endoscopic mucosal resection (EMR) of large non-pedunculated colorectal polyps (LNPCPs) of ≥20 mm is a major limitation. Data on outcomes of the endoscopic treatment of recurrence are scarce, and no evidence-based standard exists. We investigated the efficacy of endoscopic retreatment over time in a large prospective cohort.

DESIGN

Over 139 months, detailed morphological and histological data on consecutive RRA detected after EMR for single LNPCPs at one tertiary endoscopy centre were prospectively recorded during structured surveillance colonoscopy. Endoscopic retreatment was performed on cases with evidence of RRA and was performed predominantly using hot snare resection, cold avulsion forceps with adjuvant snare tip soft coagulation or a combination of the two.

RESULTS

213 (14.6%) patients had RRA (168 (78.9%) at first surveillance and 45 (21.1%) thereafter). RRA was commonly 2.5-5.0 mm (48.0%) and unifocal (78.7%). Of 202 (94.8%) cases which had macroscopic evidence of RRA, 194 (96.0%) underwent successful endoscopic therapy and 161 (83.4%) had a subsequent follow-up colonoscopy. Of the latter, endoscopic therapy of recurrence was successful in 149 (92.5%) of 161 in the per-protocol analysis, and 149 (73.8%) of 202 in the intention-to-treat analysis, with a mean of 1.15 (SD 0.36) retreatment sessions. No adverse events were directly attributable to endoscopic therapy. Further RRA after endoscopic therapy was endoscopically treatable in most cases. Overall, only 9 (4.2%, 95% CI 2.2% to 7.8%) of 213 patients with RRA required surgery.Thus 159 (98.8%, 95% CI 95.1% to 99.8%) of 161 cases with initially successful endoscopic treatment of RRA and follow-up remained surgery-free for a median of 13 months (IQR 25.0) of follow-up.

CONCLUSIONS

RRA after EMR of LNPCPs can be effectively treated using simple endoscopic techniques with long-term adenoma remission of >90%; only 16% required retreatment. Therefore, more technically complex, morbid and resource-intensive endoscopic or surgical techniques are required only in selected cases.

TRIAL REGISTRATION NUMBERS

NCT01368289 and NCT02000141.

Is colorectal endoscopic submucosal dissection safe and effective for 15-19-mm tumors?

PURPOSE

The outcomes of colorectal endoscopic submucosal dissection (ESD) in 15-19-mm tumors are unclear. This study compared the effectiveness and safety of colorectal ESD for 15-19-mm tumors and tumors exceeding that size.

METHODS

From August 2018 to December 2020, 213 cases of colorectal tumors removed by colorectal ESD at a tertiary hospital were enrolled in this study. The cases were divided into two groups according to the pathologically measured size of the resected lesion: an intermediate group (15-19 mm, n = 62) and a large group (≥ 20 mm, n = 151). The en bloc resection rate, complete resection rate, and complications were investigated retrospectively.

RESULTS

The en bloc resection rate was significantly higher in the intermediate than large group (100% vs. 94%, p = 0.049), and the mean total procedure time was shorter in the intermediate than large group (29.2 [Formula: see text] 12.6 vs. 48.4 [Formula: see text] 28.8 min, p < 0.001). However, the mean procedure speed was significantly lower in the intermediate than large group (0.25 [Formula: see text] 0.10 vs. 0.28 [Formula: see text] 0.11 cm2/min, p = 0.031). The complete resection rate, post-procedural bleeding, and perforation rate were not significantly different between the two groups. In multivariate analyses, the total procedure time and mean procedure speed were significantly associated with lesion size.

CONCLUSION

Colorectal ESD of 15-19-mm lesions is effective, and has a shorter procedure time and higher en bloc resection rate than the same procedure for larger lesions.

Cold resection for colorectal polyps: where we are and where we are going?

INTRODUCTION

Endoscopic resection of colonic precancerous lesions has been demonstrated to significantly decrease colorectal cancer (CRC) incidence and mortality. Among resection techniques, cold snare polypectomy (CSP) has been shown as a highly feasible, effective and safe option and is widely used in clinical practice, being regarded as the first-line technique for removal of small and diminutive colorectal polyps. On the other hand, conventional hot snare polypectomy (HSP) and endoscopic mucosal resection (EMR), namely the gold standard treatments for larger polyps, may be occasionally associated to complications due to electrocautery injury.

AREAS COVERED

To overcome these shortcomings of electrocautery-based resection techniques, in the last few years CSP has been increasingly assessed as a treatment option for additional indications, with a focus on nonpedunculated colorectal polyps ≥10 mm.

EXPERT OPINION

This review aims to present current and widened indications of CSP discussing the latest findings from the most remarkable studies, with an insight into technical issues, novelties and potential advances in the near future.

Endoscopic submucosal dissection techniques and technology: European Society of Gastrointestinal Endoscopy (ESGE) Technical Review

ESGE suggests conventional endoscopic submucosal dissection (ESD; marking and mucosal incision followed by circumferential incision and stepwise submucosal dissection) for most esophageal and gastric lesions. ESGE suggests tunneling ESD for esophageal lesions involving more than two-thirds of the esophageal circumference. ESGE recommends the pocket-creation method for colorectal ESD, at least if traction devices are not used. The use of dedicated ESD knives with size adequate to the location/thickness of the gastrointestinal wall is recommended. It is suggested that isotonic saline or viscous solutions can be used for submucosal injection. ESGE recommends traction methods in esophageal and colorectal ESD and in selected gastric lesions. After gastric ESD, coagulation of visible vessels is recommended, and post-procedural high dose proton pump inhibitor (PPI) (or vonoprazan). ESGE recommends against routine closure of the ESD defect, except in duodenal ESD. ESGE recommends corticosteroids after resection of  > 50 % of the esophageal circumference. The use of carbon dioxide when performing ESD is recommended. ESGE recommends against the performance of second-look endoscopy after ESD. ESGE recommends endoscopy/colonoscopy in the case of significant bleeding (hemodynamic instability, drop in hemoglobin > 2 g/dL, severe ongoing bleeding) to perform endoscopic hemostasis with thermal methods or clipping; hemostatic powders represent rescue therapies. ESGE recommends closure of immediate perforations with clips (through-the-scope or cap-mounted, depending on the size and shape of the perforation), as soon as possible but ideally after securing a good plane for further dissection.

A Look into the Future of Endoscopic Submucosal Dissection and Third Space Endoscopy: The Role for Robotics and Other Innovation

Endoscopic resection has been widely applied especially in endoscopic submucosal dissection and third space endoscopy (TSE). Flexible endoluminal robotics allow performance of endoscopic submucosal dissection with exposure of the submucosal plane for precise dissection using two robotic arms. The introduction of TSE revolutionized the horizon of therapeutic endoscopy to the submucosal space beneath and beyond the mucosa. Advantages of TSE include avoidance of full thickness incision in gastrointestinal tract through the submucosal tunneling for performance of peroral endoscopic myotomy and submucosal tunneling endoscopic resection. In future, robotic-driven devices should be developed to enhance performance of complex endoluminal procedures and TSE.

How to avoid overtreatment of benign colorectal lesions: Rationale for an evidence-based management

Implementing population-based screening programs for colorectal cancer has led to an increase in the detection of large but benign histological lesions. Currently, endoscopic mucosal resection can be considered the standard technique for the removal of benign lesions of the colon due to its excellent safety profile and good clinical results. However, several studies from different geographic areas agree that many benign colon lesions are still referred for surgery. Moreover, the referral rate to surgery is not decreasing over the years, despite the theoretical improvement of endoscopic resection techniques. This article will review the leading causes for benign colorectal lesions to be referred for surgery and the influence of the endoscopist experience on the referral rate. It will also describe how to categorize a polyp as complex for resection and consider an endoscopist as an expert in endoscopic resection. And finally, we will propose a framework for the accurate and evidence-based treatment of complex benign colorectal lesions.

Endoscopic submucosal dissection or piecemeal endoscopic mucosal resection for large superficial colorectal lesions: A cost effectiveness study

BACKGROUND AND AIMS

Endoscopic management is preferred to surgical management for large superficial colorectal lesions. However, the optimal endoscopic resection strategy (piecemeal endoscopic mucosal resection [pEMR] or endoscopic submucosal dissection [ESD]) is still debated from an economical point of view. To date, in France, there is no Health Insurance reimbursement rate for the hospital stays related to ESD. We searched to estimate the global cost of colorectal ESD and to define the most cost-effectiveness endoscopic strategy.

METHODS

A model was created to compare the cost-effectiveness of ESD and pEMR according to optical diagnosis (Japan NBI Expert Team [JNET], laterally spreading tumour [LST], CONECCT). We distinguished three groups from the same multicentre ESD cohort and compared the medical and economic outcomes: real-life ESD data (Universal-ESD or U-ESD) compared to modelled selective ESD (S-ESD JNET; S-ESD LST; S-ESD CONECCT) and exclusive pEMR strategies (Universal-EMR or U-EMR).

RESULTS

The en-bloc, R0, and curative resection rates were 97.5%, 86.5%, and 82.6%, respectively in the real life French ESD cohort of 833 colorectal lesions. U-ESD was the least-expensive strategy, with a global cost of 2,858,048.17 €, i.e. 3,431.03 €/patient and was also the most effective strategy because it avoided 774 surgeries, which was more than any other strategy. It outperformed S-ESD CONNECT (global cost = 2,951,411.44 €, and 3,543.11 €/patient, 765 surgeries avoided, S-ESD LST (global cost = 3,055,951.53 €, and 3,668.61 €/patient, 749 surgeries avoided), and S-ESD JNET (global cost = 3,547,426.97 € and 4,258.62 €/patient, 704 surgeries avoided) and U-EMR (global cost = 4,060,547.62 € and 4,874.61 €/patient, 620 surgeries avoided). Even though a model which optimized pEMR results (0% technical failure, 0% primary surgery), U-EMR strategy remained the most expansive strategy and the one that avoided the least surgeries.

CONCLUSION

ESD for all LSTs upper than 20 mm is more cost-effective than pEMR, and S-ESD.

Comparison of the morphology and histopathology of large nonpedunculated colorectal polyps in the rectum and colon: implications for endoscopic treatment

BACKGROUND AND AIMS

The risk of cancer in large nonpedunculated colorectal polyps ≥20 mm (LNPCPs) in the rectum relative to the remainder of the colon is unknown. We aimed to describe differences between rectal and colonic LNPCPs to better inform treatment decisions.

METHODS

Patients with LNPCPs referred to tertiary centers for endoscopic resection within a prospective, multicenter, observational cohort were evaluated. Data recorded were participant demographics, LNPCP location, morphology, resection modality, and histopathologic data. Multiple logistic regression analysis was used to identify those variables independently associated with rectal versus nonrectal location in the colon.

RESULTS

Patients with LNPCPs referred for endoscopic resection between July 2008 and July 2021 were included. Rectal LNPCPs (n = 618) were larger (median size, 40 mm vs 30 mm; P < .001) and more likely to be granular (79% vs 50%, P < .001) with a nodular component (53% vs 17%, P < .001) compared with nonrectal LNPCPs (n = 2787). Rectal LNPCPs were more likely to have tubulovillous histopathology (72% vs 47%, P < .001) and contain cancer (15% vs 6%, P < .001). After adjusting for the other features independently associated with location, cancer was more common in the rectum compared with the colon (odds ratio, 1.77; 95% confidence interval, 1.25-2.53).

CONCLUSIONS

This study suggests that compared with LNPCPs in the rest of the colon, rectal LNPCPs are more likely to be larger and contain more advanced pathology. These findings have implications for curative endoscopic resection techniques particularly where early cancer is present. (Clinical trial registration numbers: NCT01368289 and NCT02000141.).

Colorectal submucosa thickness in specimens obtained by EMR versus ESD: a retrospective pilot study

Accurate histopathology is the mainstay for reliable classification of resected early colorectal cancer lesions in terms of potential risk of lymph node metastasis. In particular, thickness of resected submucosa is important in cases of submucosal invasive cancer. Nevertheless, little is known about the quality and thickness of submucosal tissue obtained using different endoscopic resection techniques. In this small pilot study, we performed morphometric analysis of submucosal thickness in specimens obtained from right-sided colorectal lesions using endoscopic mucosal resection (EMR) versus endoscopic submucosal resection (ESD). Comparative measurements showed significant differences in submucosal area ≥ 1000 μm and minimum submucosal thickness per tissue section analyzed (EMR vs. ESD: 91.2 % ± 6.6 vs. 47.1 % ± 10.6, P = 0.018; 933.7 µm ± 125.1 vs. 319.0 µm ± 123.6, P = 0.009). In contrast, no significant differences were observed in variation coefficient and mean maximum submucosal thickness. Thus, unexpectedly, in this small retrospective pilot study, specimens obtained using EMR had a better preserved submucosal layer than those obtained using ESD – possibly due to the different methods of specimen acquisition. The findings should be kept in mind when attempting to resect lesions suspicious for submucosal invasive cancer.

Endoscopic submucosal dissection for superficial gastrointestinal lesions: European Society of Gastrointestinal Endoscopy (ESGE) Guideline - Update 2022

ESGE recommends that the evaluation of superficial gastrointestinal (GI) lesions should be made by an experienced endoscopist, using high definition white-light and chromoendoscopy (virtual or dye-based).ESGE does not recommend routine performance of endoscopic ultrasonography (EUS), computed tomography (CT), magnetic resonance imaging (MRI), or positron emission tomography (PET)-CT prior to endoscopic resection.ESGE recommends endoscopic submucosal dissection (ESD) as the treatment of choice for most superficial esophageal squamous cell and superficial gastric lesions.For Barrett's esophagus (BE)-associated lesions, ESGE suggests the use of ESD for lesions suspicious of submucosal invasion (Paris type 0-Is, 0-IIc), for malignant lesions > 20 mm, and for lesions in scarred/fibrotic areas.ESGE does not recommend routine use of ESD for duodenal or small-bowel lesions.ESGE suggests that ESD should be considered for en bloc resection of colorectal (but particularly rectal) lesions with suspicion of limited submucosal invasion (demarcated depressed area with irregular surface pattern or a large protruding or bulky component, particularly if the lesions are larger than 20 mm) or for lesions that otherwise cannot be completely removed by snare-based techniques.ESGE recommends that an en bloc R0 resection of a superficial GI lesion with histology no more advanced than intramucosal cancer (no more than m2 in esophageal squamous cell carcinoma), well to moderately differentiated, with no lymphovascular invasion or ulceration, should be considered a very low risk (curative) resection, and no further staging procedure or treatment is generally recommended.ESGE recommends that the following should be considered to be a low risk (curative) resection and no further treatment is generally recommended: an en bloc R0 resection of a superficial GI lesion with superficial submucosal invasion (sm1), that is well to moderately differentiated, with no lymphovascular invasion, of size ≤ 20 mm for an esophageal squamous cell carcinoma or ≤ 30 mm for a stomach lesion or of any size for a BE-related or colorectal lesion, and with no lymphovascular invasion, and no budding grade 2 or 3 for colorectal lesions.ESGE recommends that, after an endoscopically complete resection, if there is a positive horizontal margin or if resection is piecemeal, but there is no submucosal invasion and no other high risk criteria are met, this should be considered a local-risk resection and endoscopic surveillance or re-treatment is recommended rather than surgery or other additional treatment.ESGE recommends that when there is a diagnosis of lymphovascular invasion, or deeper infiltration than sm1, or positive vertical margins, or undifferentiated tumor, or, for colorectal lesions, budding grade 2 or 3, this should be considered a high risk (noncurative) resection, and complete staging and strong consideration for additional treatments should be considered on an individual basis in a multidisciplinary discussion.ESGE recommends scheduled endoscopic surveillance with high definition white-light and chromoendoscopy (virtual or dye-based) with biopsies of only the suspicious areas after a curative ESD.

Declining Colectomy Rates for Nonmalignant Colorectal Polyps in a Large, Ethnically Diverse, Community-Based Population

INTRODUCTION

Despite studies showing improved safety, efficacy, and cost-effectiveness of endoscopic resection for nonmalignant colorectal polyps, colectomy rates for nonmalignant colorectal polyps have been increasing in the United States and Europe. Given this alarming trend, we aimed to investigate whether colectomy rates for nonmalignant colorectal polyps are increasing or declining in a large, integrated, community-based healthcare system with access to advanced endoscopic resection procedures.

METHODS

We identified all individuals aged 50-85 years who underwent a colonoscopy between 2008 and 2018 and were diagnosed with a nonmalignant colorectal polyp(s) at the Kaiser Permanente Northern California integrated healthcare system. Among these individuals, we identified those who underwent a colectomy for nonmalignant colorectal polyps within 12 months after the colonoscopy. We calculated annual colectomy rates for nonmalignant colorectal polyps and stratified rates by age, sex, and race and ethnicity. Changes in rates over time were tested by the Cochran-Armitage test for a linear trend.

RESULTS

Among 229,730 patients who were diagnosed with nonmalignant colorectal polyps between 2008 and 2018, 1,611 patients underwent a colectomy. Colectomy rates for nonmalignant colorectal polyps decreased significantly from 125 per 10,000 patients with nonmalignant polyps in 2008 to 12 per 10,000 patients with nonmalignant polyps in 2018 (P < 0.001 for trend). When stratified by age, sex, and race and ethnicity, colectomy rates for nonmalignant colorectal polyps also significantly declined from 2008 to 2018.

DISCUSSION

In a large, ethnically diverse, community-based population in the United States, we found that colectomy rates for nonmalignant colorectal polyps declined significantly over the past decade likely because of the establishment of advanced endoscopy centers, improved care coordination, and an organized colorectal cancer screening program.

Risk Stratification of Endoscopic Submucosal Dissection in Colon Tumors

Background: Endoscopic submucosal dissection (ESD) is a technique proven effective in the treatment of early neoplastic lesions in the gastrointestinal tract. However, in the case of colon lesions, many doubts remain. The purpose of our study is to stratify the success rates of the ESD procedure in the colon. Materials and Methods: A retrospective analysis of 601 patients who underwent ESD procedure for colorectal neoplasm from 2016 to 2019 in Center of Bowel Treatment, Brzeziny, Poland. Excluding 335 rectal neoplasms, we selected 266 patients with lesions located in the colon. Results: Lesions located in the left colon were characterized by the statistically higher en bloc resection and success rate, compared with the right colon—87.76% vs. 73.95% (p = 0.004) and 83.67% vs. 69.75% (p = 0.007), respectively. The success rate was significantly lower in lesions with submucosal cancer, compared to low- and high-grade dysplasia (p < 0.001). Polyps located in the right colon were characterized by a slightly higher complication rate compared to the left colon, without statistical significance—13.45% vs. 9.52% (p = 0.315). Conclusions: Our results show that colonic ESD has a high success rate, especially in the left colon, with a low risk of complications, slightly higher than in the right colon.

SMALL AS WELL AS LARGE COLORECTAL LESIONS ARE EFFECTIVELY MANAGED BY ENDOSCOPIC MUCOSAL RESECTION TECHNIQUE

ABSTRACT Background Endoscopic mucosal resection (EMR) is an easy-to-use treatment option for superficial colorectal lesions, including lesions ≥20 mm. Objective To evaluate the effectiveness of EMR. Methods We evaluated 430 lesions removed by EMR in 404 patients. The lesions were analyzed according to their morphology, size, location, and histology. Lesions <20 mm were resected en bloc, whereas lesions ≥20 mm were removed by piecemeal EMR (p-EMR). Adverse events and recurrence were assessed. Results Regarding morphology, 145 (33.7%) were depressed lesions, 157 (36.5%) were polypoid lesions and 128 (29.8%) were laterally spreading lesions, with 361 (84%) lesions <20 mm and 69 (16%) ≥20 mm. Regarding histology, 413 (96%) lesions were classified as neoplastic lesions. Overall, 14 (3.3%) adverse reactions occurred, most commonly in lesions removed by p-EMR (P<0.001) and associated with advanced histology (P=0.008). Recurrence occurred in 14 (5.2%) cases, more commonly in lesions removed by p-EMR (P<0.001). Conclusion EMR is an effective technique for the treatment of superficial colorectal lesions, even of large lesions.

Cost-effectiveness analysis of endoscopic resection for colorectal laterally spreading tumors: Endoscopic submucosal dissection versus piecemeal endoscopic mucosal resection

OBJECTIVES

The cost-effectiveness of endoscopic submucosal dissection (ESD) and piecemeal endoscopic mucosal resection (pEMR) for colorectal laterally spreading tumors (LSTs) remains unclear. We examined the cost-effectiveness of these procedures for cases of colon/rectal LST-non-granular-type ≥2 cm and LST-granular-mixed-type ≥3 cm.

METHODS

We performed a simulation model analysis using parameters based on clinical data from the National Cancer Center Hospital, Tokyo, and previous literature. The number of recurrences and surgeries and the required costs for 5 years following ESD and pEMR were assessed. Japanese cost data were used in the base-case analysis, and probabilistic sensitivity analysis (PSA) was performed. The Swedish cost data were used in the scenario analysis.

RESULTS

Endoscopic submucosal dissection yielded a considerably lower number of recurrences and surgeries but required a higher cost than pEMR. The recurrence rates following ESD and pEMR were 0.9-1.3% and 21.1-25.9%, respectively. The incremental cost-effectiveness ratios for an avoided recurrence and surgery for ESD against pEMR were 376,796-476,496 JPY (3575-4521 USD) and 7,335,436-8,187,476 JPY (69,604-77,689 USD), respectively. PSA demonstrated that the probability of ESD being chosen as a more cost-effective option than pEMR was >50% at willingness-to-pay values of ≥400,000-500,000 JPY (3795-4744 USD) for avoiding a recurrence and ≥9,500,000-10,500,000 JPY (90,143-99,631 USD) for avoiding a surgery. In the scenario analysis, the required cost was also lower for ESD.

CONCLUSIONS

Our findings suggest potentially favorable cost-effectiveness of ESD, depending on cost settings and the willingness-to-pay value for avoiding recurrence/surgery.

Snare tip soft coagulation (STSC) after endoscopic mucosal resection (EMR) of large (> 20 mm) non pedunculated colorectal polyps: a systematic review and meta-analysis

Background and study aims  Endoscopic mucosal resection (EMR) of laterally spreading tumors (LSTs) > 20 mm in size can be challenging. Piecemeal EMR of these lesions results in high rates of adenoma recurrence at first surveillance colonoscopy (SC1). Snare tip soft coagulation (STSC) of post resection margins is a safe and effective technique to prevent adenoma recurrence. We conducted a systematic review and meta-analysis to evaluate the effectiveness and safety of this technique. Patients and methods  Multiple databases were searched through April 2021 for studies that reported on outcomes of post EMR STSC for LSTs > 20 mm in size. Meta-analysis was performed to determine pooled odds of adenoma recurrence as well as pooled proportion of adverse events including intraprocedural and delayed bleeding as well as intraprocedural perforation events. Results  Six studies including two randomized controlled trials (RCT) and four cohort studies with 2122 patients were included in the final analysis. Overall pooled odds of adenoma recurrence at SC1 with post EMR STSC compared to no STSC was 0.27 (95 % 0.18-0.42; I2 = 0 %), P < 0.001. Pooled rate of adenoma recurrence at SC1 in post EMR STSC cohort was 6 %. Rates of intraprocedural bleeding, delayed bleeding and intraprocedural perforation were 10.3 %, 6.5 % and 2 % respectively. Conclusions  Our results show that thermal ablation of resection margins with STSC in LSTs > 20 mm is a safe and effective technique in reducing the incidence of adenoma recurrence.

Endoscopic submucosal dissection for colorectal lesions: outcomes from a United States experience

BACKGROUND AND STUDY AIMS

Endoscopic submucosal dissection (ESD) is commonly used in Asia for resection of large non-pedunculated colorectal polyps (LNPCPs) and early (T1) colorectal cancers. It allows for en bloc removal and is often curative. We describe outcomes of colorectal ESD from a United States (US) academic medical center and compare this to international experiences.

METHODS

Retrospective review was performed of colonic lesions referred to the University of Chicago Medical Center for ESD from 2012 to 2020. Clinical and procedural data were collected.

RESULTS

The study included 78 lesions with mean size of 29.7 mm (range 10-100 mm). The overall en bloc resection rate was 73.1% (n = 57). Between the first and second half of the study, it improved from 61.5 to 84.6% (p = 0.02). Histology showed adenocarcinoma in fifteen lesions (19.2%). Of all neoplastic lesions (n = 68), resection with negative margins (R0) was achieved in 54 cases (79.4%). Adverse events occurred in 9 cases (11.5%), but most (n = 6, 66.7%) were successfully treated endoscopically. Follow-up endoscopy was performed in 46 patients (59.0%) at a mean interval of 6.8 months (SD ± 5.0 months) with two case of recurrent lesion (4.3%).

CONCLUSIONS

This study shows successful colorectal ESD outcomes at a US tertiary center. The en bloc resection rate was lower than other cohorts, but a learning curve was demonstrated. The R0 resection, lesion recurrence, and adverse event rates were similar to other non-Asian experiences, but not as favorable as in Asia [Fuccio et al. in Gastrointest Endosc 86:74-86.e17, 2017]. Increased ESD training in the US can help optimize utilization and outcomes.

Management of large polyps in a colorectal cancer screening program with fecal immunochemical test: a community- and population-based observational study

Background and study aims  The aim of this study was to analyze presentation, management, and outcomes of large polyps (LPs; ≥ 20 mm) detected in a colorectal cancer (CRC) screening program using a quantitative fecal immunochemical test (FIT). Patients and methods  This was a retrospective community- and population-based observational study of all LPs detected in patients aged 50 to 74 years between 2015 and 2019 during FIT-positive colonoscopies within the screening program organized in Alsace (France). Results  Among 13,633 FIT-positive colonoscopies, 1256 LPs (8.5 % malignant and 51.8 % nonpedunculated) were detected by 102 community gastroenterologists in 1164 patients (one in 12 colonoscopies). The sensitivity of optical diagnosis of malignancy was 54 % for nonpedunculated and 27 % for pedunculated T1 CRCs. The endoscopic resection rate was 82.7 % (95 % confidence interval [CI] 80.3-84.9) for benign LPs (70.2 % [95 % CI 66.4-74.1]) nonpedunculated, 95.2 % [95 % CI 93.4-97.1] pedunculated), varying from 0 to 100 % depending on the endoscopist. It was correlated with cecal intubation (Pearson r  = 0.49, P  < 0.01) and adenoma detection rates ( r  = 0.25, P  = 0.01). Most endoscopists did not refer patients to more experienced endoscopists, and as a result, 60 % to 90 % of 183 surgeries for benign LPs were unwarranted. Endoscopic resection was curative for 4.3 % (95 % CI 0.9-12.0) of nonpedunculated and 37.8 % (95 % CI 22.5-55.2) of pedunculated T1 CRCs. Overall, 22 endoscopic submucosal dissections had to be performed to avoid one surgery. Conclusions  Compared with current recommendations, there is tremendous room for improvement in community endoscopy practices in the diagnosis and management of LPs. Detection and polypectomy competencies are correlated and highly variable among endoscopists. Endoscopic resection is curative for 83 % of benign LPs and 16 % of T1 CRCs.

Cold versus hot polypectomy/endoscopic mucosal resection-A review of current evidence

BACKGROUND

Colonoscopy with polypectomy substantially reduces the risk of colorectal cancer (CRC) but interval cancers still account for 9% of all CRCs, some of which are due to incomplete resection.

AIM

The aim of this review is to compare the outcomes of cold and hot endoscopic resection and provide technical tips and tricks for optimizing cold snare polypectomy.

RESULTS

Cold snare polypectomy (CSP) is the standard technique for small (≤10 mm) colorectal polyps. For large colonic polyps (>10 mm), hot resection techniques with use of electrocautery (polypectomy or endoscopic mucosal resection) were recommended until recently. However, the use of electrocoagulation brings serious adverse effects in up to 9% of the patients, such as delayed bleeding, post-polypectomy syndrome and perforation. In recent years, efforts have been made to improve the polypectomy with cold snare in order to avoid these adverse effects of electrocoagulation without compromising the efficacy of the resection. Several authors have recently shown that the complication rates of CSP of polyps >10 mm is close to zero and recurrence rates varies between 5-18%. Lower recurrence rates are found in serrated lesions (<8%).

Postoperative Hospital Outcomes of Elective Surgery for Nonmalignant Colorectal Polyps: Does the Burden Justify the Indication?

INTRODUCTION

Despite the increasing availability of advanced endoscopic resections and its favorable safety profile, surgery for nonmalignant colorectal polyps has continually increased. We sought to evaluate readmission rates and outcomes of elective surgery for nonmalignant colorectal polyps on a national level in the United States.

METHODS

The Nationwide Readmissions Database (2010-2014 [International Classification of Diseases, Ninth Revision] and 2016-2018 [International Classification of Diseases, 10th Revision]) was used to identify all adult subjects (age ≥18 years) who underwent elective surgical resection of nonmalignant colorectal polyps. Multivariable analyses were performed for predictors of postoperative morbidity and 30-day readmission.

RESULTS

Elective surgery for nonmalignant colorectal polyps was performed in 108,468 subjects from 2010 to 2014 and in 54,956 subjects from 2016 to 2018, most of whom were laparoscopic. Postoperative morbidity and 30-day readmission rates were 20.5% and 8.5% from 2010 to 2014, and 13.0% and 7.6% from 2016 to 2018, respectively. Index admission mortality rates were 0.3-0.4%; mortality rates were higher in those with postoperative morbidity. Multivariable analyses revealed that male sex, ≥3 comorbidities, insurance status, and open surgery predicted an increased risk of both postoperative morbidity and 30-day readmission. In addition, postoperative morbidity (2010-2014 [odds ratio 1.58; 95% confidence interval 1.44-1.74] and 2016-2018 [odds ratio 1.55; 95% confidence interval 1.37-1.75]) predicted early readmission.

DISCUSSION

In this investigation of national practices, elective surgery for nonmalignant colorectal polyps remains common. There is considerable risk of adverse postoperative outcomes, which highlights the importance of increasing awareness of the range of endoscopic resections and referring subjects to expert endoscopy centers.

Metachronous neoplasms in patients with laterally spreading tumours during surveillance

Background

Laterally spreading tumours represent a major challenge for endoscopic detection and resection.

Objective

To examine synchronous and metachronous neoplasms in patients with laterally spreading tumours.

Methods

We prospectively collected colonoscopy and histopathology data from patients who underwent colonoscopy in our centre at up to 6 years' follow‐up. Post‐resection surveillance outcomes between laterally spreading tumours, flat colorectal neoplasms 10 mm or greater, and large polypoid colorectal neoplasms, polypoid colorectal neoplasms 10 mm or greater, were compared.

Results

Between 2008 and 2012, 8120 patients underwent colonoscopy for symptoms (84.6%), screening (6.7%) or surveillance (8.7%). At baseline, 151 patients had adenomatous laterally spreading tumours and 566 patients had adenomatous large polypoid colorectal neoplasms. Laterally spreading tumour patients had more synchronous colorectal neoplasms than large polypoid colorectal neoplasm patients (mean 3.34 vs. 2.34, p < 0.001). Laterally spreading tumour patients significantly more often developed metachronous colorectal neoplasms (71.6% vs. 54.2%, p = 0.0498) and colorectal neoplasms with high grade dysplasia/submucosal invasion than large polypoid colorectal neoplasm patients (36.4% vs. 15.8%, p < 0.001). After correction for age and gender, laterally spreading tumour patients were more likely than large polypoid colorectal neoplasm patients to develop a colorectal neoplasm with high grade dysplasia or submucosal invasion (hazard ratio 2.9, 95% confidence interval 1.8–4.6). The risk of metachronous colorectal cancer was not significantly different in laterally spreading tumours compared to large polypoid colorectal neoplasm patients.

Conclusion

Patients with laterally spreading tumours developed more metachronous colorectal neoplasms with high grade dysplasia/submucosal invasion than large polypoid colorectal neoplasm patients. Based on these findings endoscopic treatment and surveillance recommendations for patients with laterally spreading tumours should be optimised.

Summarize the established knowledge on this subject

Laterally spreading tumours (LSTs) are a heterogeneous group of large, predominantly benign flat neoplasms that can be endoscopically treated, requiring additional time and expertise

LSTs consist of different endoscopic subtypes which are predictive of the risk of submucosal invasion (SMI)

Patients with LSTs harbour more synchronous neoplasms than patients with large polypoid colorectal neoplasms (LP‐CRNs)

What are the significant and/or new findings of this study?

Patients with LSTs more frequently have metachronous neoplasms than patients with LP‐CRNs, justifying strict surveillance

LSTs can be effectively managed by conventional endoscopic resections in most cases

Pathological Analysis and Endoscopic Characteristics of Colorectal Laterally Spreading Tumors

Objective

This study aims to analyze the endoscopic and pathological characteristics of colorectal laterally spreading tumors (LSTs) to assist malignant risk stratification to inform selection of the appropriate treatment strategy.

Methods

Patients with colorectal LST were selected as retrospective study objects. Characteristics, including endoscopic findings and the most common site of LSTs of different diameters and histological types, were analyzed. The risk factors for malignancy in colorectal LST were explored by multivariate logistic regression analysis.

Results

LSTs with diameters of ≥20 mm were found mainly in the rectum and mainly with granular-mixed (G-M) morphology (36% and 44.6%, respectively; p < 0.05), while LSTs with diameters of <20 mm were found mainly in the ascending colon and mainly with granular-homogenous (G-H) morphology (40.9% and 46.2%, respectively; p < 0.05). Adenoma was the main histological type in patients with tumors of all diameters. However, the cancerization rate of LSTs was 31% in patients with tumor diameter ≥20 mm, while there was no invasive cancer in patients with tumor diameter < 20 mm. In the low-grade dysphasia (adenoma) group, most of the lesions were located in the ascending colon and most had the morphology LST-G-H (35.8% and 39.2%, respectively; p < 0.05). In the cancerization group, most of the lesions were located in the rectum, with the morphology LST-G-M (51.6% and 67.2%, respectively; p < 0.05), and the diameter was larger than that of the adenoma group (33.84 ± 17.99 mm vs 21.68 ± 8.99 mm).

Conclusion

The rectum was the most common site for an LST with a diameter ≥20 mm and cancerization, of which the morphology was mainly LST-G-M (endoscopic submucosal dissection is the preferred treatment for this type of LST). LST malignancy was found to be correlated with lesion diameter, location, and morphological appearance.

Artificial intelligence for non-polypoid colorectal neoplasms

The miss rate of flat advanced colorectal neoplasia is still unacceptably high, especially in the Western setting, notwithstanding the widespread implementation of quality improvement programs and training. It is well known that flat morphology is associated with miss rate of colorectal neoplasia, and that this subset of lesions often shows a more aggressive biological behaviour. Artificial intelligence (AI) applied to the detection of colorectal neoplasia has been shown to increase adenoma detection rate, consistently across all lesion sizes and locations in the colon. However, there is still uncertainty whether AI can reduce the miss rate of flat advanced neoplasia, mainly because all published trials report a low number of flat colorectal lesions in their training sets, and this could reduce AI accuracy for this subset of lesions. In addition, flat lesions have different morphologies with variable prevalence and potentially different accuracy in their detection. For example, the subtle appearance and rarer frequency of a non-granular laterally spreading tumor (LST) could be much harder to identify than a granular mixed LST. In this review, we present a summary of the evidence on the role of AI in the identification of colorectal flat neoplasia, with a focus on data regarding presence of LSTs in the training/validation sets of the AI systems currently available on the market.

The risk factors for delayed bleeding after endoscopic resection of colorectal tumors: a meta-analysis

INTRODUCTION

The most common complication of post-colorectal endoscopic resection is delayed bleeding. The assessment of risk factors for delayed bleeding provides important and useful information in standard clinical operations. The risk factors have been previously reported; however, they remain inconsistent across different studies.

AREAS COVERED

In this meta-analysis, the patient conditions, lesion-related factors, and operation-related factors were compared between delayed bleeding and no bleeding. PubMed, Cochrane, Embase, China National Knowledge Infrastructure (CNKI), and Wanfang Database were searched to identify eligible studies. Pooled odds ratio (OR) and 95% confidence intervals (CI) were calculated along with heterogeneity.

EXPERT OPINION

This study is the first meta-analysis to investigate risk factors for colorectal delayed bleeding. We found several risk factors contributing to this condition: colorectal tumors located in the proximal colon, a history of antithrombotic drug use, high-grade intraepithelial neoplasia or early cancer, piecemeal resection, intraoperative hemorrhage, no clip placement, and severe submucosal fibrosis. Despite our findings, we also conclude that more high-quality, large-scale clinical randomized controlled studies are needed due to limited retrospective studies at present. Future therapeutic colonoscopies should focus on precise diagnosis, treatment safety, and management during the perioperative period.

Pathologic Evaluation of Large Colorectal Endoscopic Submucosal Dissections: An Analysis of 279 Cases With Emphasis on the Importance of Multidisciplinary Work and Establishing Examination Protocols

Background. Endoscopic submucosal dissections (ESDs) allow removal of large gastrointestinal tumors and help patients avoid major oncologic surgery. In this study, the challenges and development of approaches toward successfully handling ESDs were analyzed in 279 colorectal specimens (114 rectal, 47 left, 118 right colonic; 90% adenoma with/without carcinoma). Methods. Each specimen was processed according to an established protocol including gross photography, mapping, and total submission for histopathologic examination. Results. Mean lesion size was 4.2 cm (range: 0.5-22 cm; 28% ≥5 cm; 6% ≥10 cm). Invasive carcinoma was present in 38 cases (14%), which had a mean overall tumor size of 3.8 cm (range: 1.1-17.5 cm), and mean largest size of the invasive component was 0.93 cm (range: 0.04-3 cm). Fifteen cases were staged as pT1a (submucosal invasion of <1000 µm) and 13 cases as pT1b (submucosal invasion of ≥1000 µm). En-bloc and R0 resection rates were 99.3% and 90.6%, respectively. Conclusion. Various histopathologic challenges were encountered, which were carefully evaluated by dedicated pathologists with familiarity to the subtleties in handling and reporting these specimens. We recommend these specimens to be prepared in the endoscopy suite, submitted to the Pathology Department oriented, pinned, and placed into copious amount of fixative. Total sampling, gross photography, mapping, and proper fixation are crucial components in the histopathologic evaluation. Micromeasurement of invasion depth and substaging per European/Japanese guidelines as well as accurate measurement of the distance from the resection margins are highly recommended. In conclusion, ESD is an adequate method that can be successfully implemented in a tertiary care center to perform en-bloc and margin-free resections of clinically selected large colorectal superficial lesions.

Intra-procedural and delayed bleeding after resection of large colorectal lesions: The SCALP study

Background and aim

The safety of endoscopic resection of large colorectal lesions (LCLs) (≥20 mm) is clinically relevant. The aim of the present study was to assess the rate of post-resection adverse events (AEs) in a real-life setting.

Patients and methods

In a prospective, multicentre, observational study, data from consecutive resections of LCLs over a 6-month period were collected in 24 centres. Patients were followed up at 15 days from resection for AEs. The primary endpoint was intra-procedural bleeding according to lesion morphology. Secondary endpoints were delayed bleeding and perforation. Patient and polyp characteristics, and polypectomy techniques were analysed with respect to the bleeding events.

Results

In total, 1504 patients (female/male: 633/871, mean age, 66.1) with 1648 LCLs (29.1% pedunculated and 70.9% non-pedunculated lesions) were included. Overall, 168 (11.2%) patients had post-resection bleeding (8.5 and 2.0% immediate and delayed, respectively), while 15 (1.0%) cases of perforation occurred. Independent predictors of immediate bleeding for pedunculated lesions were bleeding prophylaxis (odds ratio (OR) 0.28, 95% confidence interval (CI) 0.13-0.62), simple polypectomy (versus endoscopic mucosal resection, OR 0.38, 95% CI 0.17-0.88) and inpatient setting (OR 2.21, 95% CI 1.07-5.08), while bleeding prophylaxis (OR 0.37, 95% CI 0.30-0.98), academic setting (OR 0.27, 95% CI 0.12-0.54) and size (OR 1.03, 95% CI 1.00-1.05) were predictors for those non-pedunculated. Indication for colonoscopy (screening versus diagnostic (OR 0.33, 95% CI 0.12-0.86)), antithrombotic therapy (OR 3.12, 95% CI 1.54-6.39) and size (OR 2.34, 95% CI 1.12-4.87) independently predicted delayed bleeding.

Conclusions

A low rate of post-resection AEs was observed in a real-life setting, reassuring as to the safety of endoscopic resection of ≥2 cm colorectal lesions. Bleeding prophylaxis reduced the intra-procedural bleeding risk, while antithrombotic therapy increased delayed bleeding.CLINICALTRIAL: (NCT02694120).

Safety and efficacy of endoscopic submucosal dissection for rectal neoplasia: a multicenter North American experience

Background and aims  Rectal lesions traditionally represent the first lesions approached during endoscopic submucosal dissection (ESD) training in the West. We evaluated the safety and efficacy of rectal ESD in North America. Methods  This is a multicenter retrospective analysis of rectal ESD between January 2010 and September 2018 in 15 centers. End points included: rates of en bloc resection, R0 resection, adverse events, comparison of pre- and post-ESD histology, and factors associated with failed resection. Results  In total, 171 patients (median age 63 years; 56 % men) underwent rectal ESD (median size 43 mm). En bloc resection was achieved in 141 cases (82.5 %; 95 %CI 76.8-88.2), including 24 of 27 (88.9 %) with prior failed endoscopic mucosal resection (EMR). R0 resection rate was 74.9 % (95 %CI 68.4-81.4). Post-ESD bleeding and perforation occurred in 4 (2.3 %) and 7 (4.1 %), respectively. Covert submucosal invasive cancer (SMIC) was identified in 8.6 % of post-ESD specimens. There was one case (1/120; 0.8 %) of recurrence at a median follow-up of 31 weeks; IQR: 19-76 weeks). Older age and higher body mass index (BMI) were predictors of failed R0 resection, whereas submucosal fibrosis was associated with a higher likelihood of both failed en bloc and R0 resection. Conclusion  Rectal ESD in North America is safe and is associated with high en bloc and R0 resection rates. The presence of submucosal fibrosis was the main predictor of failed en bloc and R0 resection. ESD can be considered for select rectal lesions, and serves not only to establish a definitive tissue diagnosis but also to provide curative resection for lesions with covert advanced disease.

Management of Complications of Colorectal Submucosal Dissection

Endoscopic submucosal dissection (ESD) is a useful procedure for the treatment of superficial gastrointestinal neoplasm. Compared with endoscopic mucosal resection (EMR), ESD has several benefits, which include resectability of various difficult lesion, accurate histologic assessment of specimen, and lower recurrence rate. However, the risk of procedure- related complications is higher with ESD than with EMR. Moreover, because the colon has a thin wall and limited endoscopic maneuverability, ESD is considered a more challenging and risky procedure when performed in the colon than in the stomach. ESD-related complications are more likely to occur. The significant complications associated with ESD are bleeding, perforation, coagulation syndrome and stenosis, most of which can be treated and prevented by endoscopic intervention and preparation. Therefore, it is important to know how to occur and manage the ESD related complication.