Endoscopic Mucosal Resection with Circumferential Mucosal Incision for Colorectal Neoplasms: Comparison with Endoscopic Submucosal Dissection and between Two Endoscopists with Different Experiences

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.

Multicenter evaluation of recurrence in endoscopic submucosal dissection and endoscopic mucosal resection in the colon: A Western perspective

BACKGROUND

While colon endoscopic mucosal resection (EMR) is an effective technique, removal of larger polyps often requires piecemeal resection, which can increase recurrence rates. Endoscopic submucosal dissection (ESD) in the colon offers the ability for en bloc resection and is well-described in Asia, but there are limited studies comparing ESD vs EMR in the West.

AIM

To evaluate different techniques in endoscopic resection of large polyps in the colon and to identify factors for recurrence.

METHODS

The study is a retrospective comparison of ESD, EMR and knife-assisted endoscopic resection performed at Stanford University Medical Center and Veterans Affairs Palo Alto Health Care System between 2016 and 2020. Knife-assisted endoscopic resection was defined as use of electrosurgical knife to facilitate snare resection, such as for circumferential incision. Patients ≥ 18 years of age undergoing colonoscopy with removal of polyp(s) ≥ 20 mm were included. The primary outcome was recurrence on follow-up.

RESULTS

A total of 376 patients and 428 polyps were included. Mean polyp size was greatest in the ESD group (35.8 mm), followed by knife-assisted endoscopic resection (33.3 mm) and EMR (30.5 mm) (P < 0.001). ESD achieved highest en bloc resection (90.4%) followed by knife-assisted endoscopic resection (31.1%) and EMR (20.2%) (P < 0.001). A total of 287 polyps had follow-up (67.1%). On follow-up analysis, recurrence rate was lowest in knife-assisted endoscopic resection (0.0%) and ESD (1.3%) and highest in EMR (12.9%) (P = 0.0017). En bloc polyp resection had significantly lower rate of recurrence (1.9%) compared to non-en bloc (12.0%, P = 0.003). On multivariate analysis, ESD (in comparison to EMR) adjusted for polyp size was found to significantly reduce risk of recurrence [adjusted hazard ratio 0.06 (95%CI: 0.01-0.57, P = 0.014)].

CONCLUSION

In our study, EMR had significantly higher recurrence compared to ESD and knife-assisted endoscopic resection. We found factors including resection by ESD, en bloc removal, and use of circumferential incision were associated with significantly decreased recurrence. While further studies are needed, we have demonstrated the efficacy of ESD in a Western population.

Comparison of precutting endoscopic mucosal resection and endoscopic submucosal dissection for large (20-30 mm) flat colorectal lesions

BACKGROUND AND AIM

The complete and safe removal of large (≥ 20 mm) colorectal lesions is an area of concern. Endoscopic submucosal dissection (ESD) effectively removes these lesions compared with endoscopic mucosal resection (EMR). However, ESD requires advanced techniques, longer procedure time, and high cost. Precutting EMR (EMR-P) is a modified EMR method that overcomes the limitations of EMR. This study aimed to compare the efficacy and safety of EMR-P and ESD in large (20-30 mm) flat colorectal lesions.

METHODS

This was a retrospective analysis of cases in which 20- to 30-mm flat colorectal lesions were resected at Seoul St. Mary's Hospital from January 2014 to December 2019. Propensity score matching was performed to control for possible confounders.

RESULTS

Two hundred and ninety-nine patients were included in this study. After matching, 90 patients were assigned to each group. There were no significant difference in complete resection rates (92.2% vs 92.2%, P = 1.000), en bloc resection rates (95.6% vs 97.8%, P = 0.682), and mean size of lesions (22.9 ± 3.1 mm vs 23.0 ± 3.1 mm, P = 0.867) between EMR-P and ESD. Procedure time was significantly shorter with EMR-P (11.0 ± 6.5 min vs 37.0 ± 19.3 min, P < 0.001). The adverse events rate was not significantly different between both groups. No local recurrence occurred in both groups.

CONCLUSIONS

Precutting EMR was not significantly different to ESD in terms of complete resection rate and en bloc resection rate for 20- to 30-mm flat colorectal lesions without fibrosis. Furthermore, EMR-P has shorter procedure time than ESD. EMR-P could be considered one of standard treatments for large flat colorectal lesions.

Long-term clinical outcomes of endoscopic submucosal dissection for colorectal neoplasia with or without the hybrid technique

AIM

The main aim of this study was to compare the long-term outcome of a conventional colorectal endoscopic submucosal dissection (ESD) in which submucosal dissection was continued throughout until the completion of resection (ESD-T) to hybrid endoscopic submucosal dissection (ESD-H) in the colorectum.

METHOD

Medical records of 836 colorectal neoplasia patients treated by ESD-T or ESD-H were reviewed. ESD-H was defined as colorectal ESD with additional snaring in the final stage of the procedure. Primary outcomes were the overall and metastatic recurrence rates. Secondary outcomes were short-term outcomes such as the en bloc resection rate, procedure time and adverse events.

RESULTS

The overall recurrence rate was higher in the ESD-H than in the ESD-T group (5.7% vs 0.7%, P = 0.001). The metastatic recurrence rate showed no significant difference between these groups (1.4% vs 1.4%, P = 1.000). Multivariate analysis revealed that a failed en bloc resection (hazard ratio 24.097; 95% CI 5.446-106.237; P < 0.001) and larger tumour size (hazard ratio 1.042; 95% CI 1.014-1.070; P = 0.003) were independently associated with overall recurrence. The ESD-H group showed a lower en bloc resection rate (56.8% vs 96.5%, P < 0.001), shorter procedure time (45.6 vs 54.3 min, P < 0.001) and higher perforation rate (10.3% vs 6.0%, P = 0.029).

CONCLUSION

Although long-term outcomes in terms of overall recurrence are inferior following ESD-H, a failed en bloc resection and large tumour size are the only independent risk factors for recurrence. Further investigations are warranted to improve the long-term outcomes of ESD-H.

Tip-in versus conventional endoscopic mucosal resection for flat colorectal neoplasia 10 mm or larger in size

PURPOSE

A modified endoscopic mucosal resection (EMR) technique, Tip-in EMR, was recently introduced to enhance the complete resection of colorectal neoplasia (CRN). We aimed to evaluate the feasibility of Tip-in EMR for flat CRNs.

METHODS

From January to September 2018, conventional or Tip-in EMR was consecutively performed for 112 flat CRNs ≥ 10 mm in diameter. Tip-in EMR was performed when en bloc snaring was impossible with conventional EMR or when a lesion was inadequately lifted owing to a previous forceps biopsy. We retrospectively collected the clinical, procedural, and histologic data of the conventional and Tip-in EMR groups and compared the en bloc resection rate, complete resection rate, and complications between the two groups.

RESULTS

Among 112 flat CRNs of 80 patients, conventional EMR and Tip-in EMR were performed for 74 and 38 lesions, respectively. The median lesion size was 12 (10-27) mm. Tip-in EMR was superior to conventional EMR in terms of en bloc resection (94.7% vs. 77.0%, p = 0.018) and histologic complete resection (76.3% vs. 54.1%, p = 0.022). There was no difference in postprocedural bleeding between the two groups; however, overall adverse events, including bleeding and postpolypectomy electrocoagulation syndrome, were more frequent in the Tip-in EMR group.

CONCLUSIONS

Tip-in EMR is a feasible technique for flat colorectal lesions ≥ 10 mm and is superior to conventional EMR with respect to en bloc and complete resection rates. The safety profiles of Tip-in EMR and conventional EMR should be compared via large-scale prospective studies.

Efficacy and Safety of Complete Endoscopic Resection of Colorectal Neoplasia Using a Stepwise Endoscopic Protocol with SOUTEN, a Novel Multifunctional Snare

BACKGROUND/AIMS

A multifunctional snare SOUTEN has a sharp tip at the top of the snare loop that enables incision of the mucosa, dissection of the submucosal layer, and snaring of lesion. This study assessed the efficacy and safety of complete endoscopic resection of colorectal neoplasia using SOUTEN.

METHODS

We analyzed the rates of gross en bloc resection and complete resections of 108 consecutive tumors from 69 patients resected by precutting endoscopic mucosal resection (precutting), hybrid endoscopic submucosal dissection (hybrid), or conventional endoscopic submucosal dissection (conventional) using SOUTEN.

RESULTS

Out of the 108 tumors, 50 were resected by precutting, 27 were resected by hybrid after attempting precutting, and the remaining 31 were resected by conventional after attempting precutting and hybrid resections. The median tumor sizes were 14.5 mm for precutting, 16.4 mm for hybrid, and 21.1 mm for conventional. The success rate of gross en bloc resection and histological complete resection were 100% and 94.0% for precutting, 96.4% and 96.4% for hybrid, and 100% and 100% for conventional method, respectively. No procedure-related complication occurred.

CONCLUSION

By using SOUTEN, precutting and hybrid were successfully performed on 10-30 mm tumors with a shorter procedure time than conventional without major complications.

Pyogenic Liver Abscess Caused by Endoscopic Submucosal Dissection for Early Colon Cancer

Endoscopic submucosal dissection (ESD) is widely used for the treatment of colorectal neoplasia in patients who are candidates for endoscopic resection. In particular, pyogenic liver abscess (PLA), although rare, can occur. To our knowledge, there are no reports of PLA cases after ESD. Therefore, we report a rare case of PLA caused by ESD. A 76-year-old man was referred from a local clinic and admitted to our hospital for colonic ESD for a large polypoid mass. During colonoscopy, a 5-cm mass was seen in the cecum. ESD was performed. Four days after the procedure, he complained of myalgia and abdominal discomfort. Computed tomography revealed a 5.4-cm PLA in the medial segments of the liver. He was treated with antibiotics, and a percutaneous drainage catheter was inserted. Here, we report a very rare complication (PLA) after ESD. In conclusion, comprehensive awareness of the development of PLA is needed in ESD cases.

Introduction of endoscopic submucosal dissection in the West

Endoscopic submucosal dissection (ESD) is well established in Asia as a modality for selected advanced lesions of both the upper and lower gastrointestinal tract, but ESD has not attained the same niche in the West due to a variety of reasons. These include competition from traditional surgery, minimally invasive surgery and endoscopic mucosal resection. Other obstacles to ESD introduction in the West include time commitment for learning and doing procedures, a steep learning curve, special equipment, lack of mentors, cost issues, interdisciplinary conflicts, concern regarding complications and lack of support from institutions and interfacing departments. There are intrinsic differences in pathology prevalence (e.g., early gastric cancer) between the two regions that are less conducive for ESD implementation in the West. We will elaborate on these issues and suggest measures as well as a protocol to overcome these obstacles and hopefully allow introduction of ESD as a tenable option for appropriate patients.

Endoscopic submucosal dissection in the West: Current status and future directions

Endoscopic submucosal dissection (ESD) was first conceptually described almost 30 years ago in Japan and is now widely practiced throughout East Asia. ESD expands the boundaries of endoscopic resection (ER) by allowing en bloc resection of large early neoplastic lesions within the gastrointestinal tract (GIT). This offers advantages over other ER techniques by facilitating definitive histological staging and curative treatment of early cancer in selected cases. Indeed, the experience of ESD in Eastern countries is significant, and excellent outcomes from high-volume centers are reported. The potential benefits of ESD are recognized by Western endoscopists, but its adoption has been limited. A number of factors contribute to this, including epidemiological differences in GIT neoplasia between Western and Eastern populations and limitations in training opportunities. In this review, we discuss the role of ESD, its current status and the future in Western endoscopic practice.