Knife-assisted snare resection (KAR) of large and refractory colonic polyps at a Western centre: Feasibility, safety and efficacy study to guide future practice

Rectal neuroendocrine tumours and the role of emerging endoscopic techniques

Rectal neuroendocrine tumours represent a rare colorectal tumour with a 10 fold increased prevalence due to incidental detection in the era of colorectal screening. Patient outcomes with early diagnosis are excellent. However endoscopic recognition of this lesion is variable and misdiagnosis can result in suboptimal endoscopic resection with subsequent uncertainty in relation to optimal long-term management. Endoscopic techniques have shown particular utility in managing this under-recognized neuroendocrine tumour.

Modified endoscopic mucosal resection techniques for treating precancerous colorectal lesions

Endoscopic mucosal resection (EMR) is a technique allowing efficacious and minimally invasive resection of precancerous lesions across the entire gastrointestinal tract. However, conventional EMR, involving injection of fluid into the submucosal space, is imperfect, given the high rate of recurrence of post-endoscopic resection adenoma, especially after piecemeal resection. In light of these observations, modifications of the technique have been proposed to overcome the weakness of conventional EMR. Some of them were designed to maximize the chance of en bloc resection—cap-assisted EMR, underwater EMR, tip-in EMR, precutting, assisted by ligation device—while others were designed to minimize the complications (cold EMR). In this review, we present their modes of action and summarize the evidence regarding their efficacy and safety.

Current Endoscopic Resection Techniques for Gastrointestinal Lesions: Endoscopic Mucosal Resection, Submucosal Dissection, and Full-Thickness Resection

Background

Endoscopic resection of dysplastic lesions in early stages of cancer reduces mortality rates and is recommended by many national guidelines throughout the world. Snare polypectomy and endoscopic mucosal resection (EMR) are established techniques of polyp removal. The advantages of these methods are their relatively short procedure times and acceptable complication rates. The latter include delayed bleeding in 0.9% and a perforation risk of 0.4-1.3%, depending on the size and location of the resected lesion. EMR is a recent modification of endoscopic resection. A limited number of studies suggest that larger lesions can be removed en bloc with low complication rates and short procedure times. Novel techniques such as endoscopic submucosal dissection (ESD) are used to enhance en bloc resection rates for larger, flat, or sessile lesions. Endoscopic full-thickness resection (EFTR) is employed for non-lifting lesions or those not easily amenable to resection. Procedures such as ESD or EFTR are emerging standards for lesions inaccessible to EMR techniques.

Summary

Endoscopic treatment is now regarded as first-line therapy for benign lesions.

Key Message

Endoscopic resection of dysplastic lesions or early stages of cancer is recommended. A plethora of different techniques can be used dependent on the lesions.

Does precutting prior to endoscopic piecemeal resection of large colorectal neoplasias reduce local recurrence? A KASID multicenter study

BACKGROUND

It would be expected that local recurrence could be reduced by performing precutting (with sufficient margins) prior to endoscopic piecemeal mucosal resection (EPMR). We explored the clinical outcomes and local recurrence after precutting EPMR of large colorectal neoplasias.

METHODS

Between January 2005 and December 2015, in total, 223 patients with colorectal neoplasias ≥ 2 cm in diameter removed via EPMR in four tertiary hospitals were enrolled. The patients were divided into a precut EPMR group (n = 62) and a non-precut EPMR group (n = 161). We retrospectively evaluated clinical outcomes and factors associated with local recurrence.

RESULTS

The mean total procedure time was significantly shorter in the non-precut EPMR group than in the precut EPMR group. However, the number of pieces, and the complete resection and recurrence rates, did not differ significantly [for the latter, precut 8.1% vs. non-precut 9.9%, P = 0.668]. The complete resection rate, number of pieces, and use of argon plasma coagulation (APC) were significantly associated with the local recurrence rate on univariate analysis. In the Cox's proportional hazards model, prophylactic APC [hazard ratio 0.307, 95% confidence interval (CI) 0.114-0.823; P = 0.019] and complete resection rate (odds ratio 0.083, 95% CI 0.011-0.655; P = 0.018) were significantly associated with the local recurrence rate.

CONCLUSION

Precutting prior to EPMR did not significantly reduce the local recurrence rate or the number of resected pieces. Histologically complete resection, reducing the number of pieces, and prophylactic APC seem to be important in terms of reducing local recurrence.

Hybrid endoscopic submucosal dissection: An alternative resection modality for large laterally spreading tumors in the cecum?

BACKGROUND

Endoscopic resection for large, laterally spreading tumors (LSTs) in the cecum is challenging. Here we report on the clinical outcomes of hybrid endoscopic submucosal dissection (ESD) in large cecal LSTs.

METHODS

We retrospectively reviewed data from patients with cecal LSTs ≥ 2 cm who underwent ESD or hybrid ESD procedures between January of 2008 and June of 2019. We compared the baseline characteristics and clinical outcomes, including procedure time, the en bloc and complete resection rates, and adverse events.

RESULTS

A total of 62 patients were enrolled in the study. There were 27 patients in the ESD group and 35 patients in the hybrid ESD group, respectively. Hybrid ESD was more used for lesions with submucosal fibrosis. No other significant differences were found in patient characteristics between the two groups. The hybrid ESD group had a significantly shorter procedure time compared with the ESD group (27.60 ± 17.21 vs. 52.63 ± 44.202 min, P = 0.001). The en bloc resection rate (77.1% vs. 81.5%, P = 0.677) and complete resection rate (71.4% vs. 81.5%, P = 0.359) of hybrid ESD were relatively lower than that of the ESD group in despite of no significant difference was found. The perforation and post-procedure bleeding rate (2.9% vs. 3.7%, P = 0.684) were similar between the two groups. One patient perforated during the ESD procedure, which was surgically treated. One patient in the hybrid ESD group experienced post-procedure bleeding, which was successfully treated with endoscopic hemostasis. Post-procedural fever and abdominal pain occurred in six patients in the ESD group and five patients in the hybrid ESD group. One patient in the ESD group experienced recurrence, which was endoscopically resected.

CONCLUSION

The results of this study indicate that hybrid ESD may be an alternative resection strategy for large cecal LSTs with submucosal fibrosis.

Future of Endoscopy: Brief review of current and future endoscopic resection techniques for colorectal lesions

Endoscopic treatment of colorectal lesions has seen major developments in the last decade. It is now considered curative for intramucosal and superficial submucosal cancers. Endoscopic Mucosal Resection in expert hands has very good outcomes with low complication rates but recurrence and inadequate treatment of early cancers remain an issue. This has led to a technical evolution that can lead to one piece resection of neoplasia. This includes a range of techniques from knife assisted snare resection (KAR), endoscopic submucosal dissection (ESD) to full thickness resections. This article reviews all the resection techniques and the evidence base behind them.

Review on colorectal endoscopic submucosal dissection focusing on the technical aspect

BACKGROUND

Endoscopic submucosal dissection (ESD) enables removal of broad-based colorectal polyps or lateral spreading tumors with a higher rate of en bloc resection and a lower risk of local recurrence. However, it is technically demanding. Over the past 20 years, various equipment and innovative techniques have been developed to reduce the difficulty of ESD. The information in the literature is scattered. Our aim is to provide a comprehensive review on the setup and technical aspects of colorectal ESD.

METHODS

We searched the PubMed database and systemically reviewed all original and review articles related to colorectal ESD. Further manual search according to reference lists of identified articles were done. The selected articles were categorized and reviewed. Original figures were created to help readers understand some of the ESD techniques.

RESULTS

A total of 216 articles were identified, in which 25 of them were review articles and 191 of them were original articles. They were categorized and reviewed. An in-depth appraisal of the setting, equipment, and technical aspects of colorectal ESD was performed.

CONCLUSIONS

Although ESD is a technically demanding procedure that requires expert endoscopic skills, it can be mastered. With good peri-procedural preparation, sufficient knowledge of the equipment, and thorough understanding of the useful endoscopic tricks and maneuvers, colorectal ESD can be performed smoothly and safely.

Long-term follow-up after endoscopic submucosal dissection of colorectal lesions in a Spanish cohort

INTRODUCTION

ESD in the colon is an increasingly important technique in Western countries. There are few studies that include long term follow-up.

AIM

to analyze the long term recurrence free survival rate after ESD and to compare recurrence rates according to different variables.

METHODS

this was a prospective observational study of patients with a planned ESD from September 2008 to December 2015. When it was not possible to achieve an ESD, hybrid ESD was performed, either en bloc or piecemeal. Kaplan-Meier survival curves were used to assess the five year local recurrence free survival rate and the recurrence rate. The results were compared according to different factors.

RESULTS

of the 89 patients scheduled for ESD who were initially enrolled in the study, 69 were finally included for follow-up. ESD was performed in 31 (45%) patients, KAR in eleven (16%) and pKAR in 27 (39%). The median follow-up was 27 months (range 6-60). The five year disease free survival rate was 81%. The average number of endoscopies needed to eliminate recurrence was two (range 2-7) and no patient required surgery for this reason. The recurrence rate was significantly higher in piecemeal resections vs en bloc resections (27% vs 15%, p = 0.036) and R1 resections vs R0 resections (26% vs 0%, p = 0.034). The presence of affected or unknown lateral margins in en bloc resections without other poor prognosis factors had higher recurrence rates but the difference was not statistically significant (28% vs 0%, p = 0.09).

CONCLUSIONS

in our study, the five year disease free survival rate was 81% and no patient required surgery during follow-up. Piecemeal and R1 resections had significantly higher recurrence rates, as well as LM involvement, although this was not statistically significant.

Switching from endoscopic submucosal dissection to salvage piecemeal knife-assisted snare resection to remove a lesion: A preoperative risk score from the beginning

BACKGROUND AND AIMS

endoscopic submucosal dissection (ESD) in the Western setting remains a challenge. Therefore, other simplified techniques such as knife-assisted snare resection (KAR) have been reported to overcome this issue.

METHODS

patients who underwent an ESD for the treatment of gastrointestinal neoplasms were included in a retrospective cross-sectional observational study. Factors associated with the end of ESD as a salvage p-KAR were identified and a logistic regression model was developed.

RESULTS

a total of 136 lesions in 133 patients were analyzed. Operator experience of under 50 cases and the combination of lesion size > 30 mm and colorectal location were independent predictive factors for switching to a salvage p-KAR according to the multivariate logistic regression analysis. We developed a risk scoring system based on these four variables (experience, size, location and the combination of size and location) with a receiver operating characteristic curve of 0.81 (95% CI: 0.74-0.89). The diagnostic accuracy of the score for a cut-off point ≥ 5 had a sensitivity of 0.79 (95% CI: 0.66-0.93) and a specificity of 0.71 (95% CI: 0.61-0.80).

CONCLUSION

a simple predictive score system that includes four preoperative factors accurately predicts ESD to finish as a p-KAR. A careful selection of cases considering these variables could be useful to achieve better outcomes in the Western setting.

Colorectal endoscopic submucosal dissection (ESD)

Endoscopic submucosal dissection (ESD) is an interventional procedure for en-bloc resection of gastrointestinal lesions. ESD is a challenging and can involve a reasonable degree of risk, therefore case selection is of crucial importance, especially in the colo-rectum. This procedure should be mainly used for dissection of lesions when there is a high suspicion of superficial malignant invasion; several classifications have been proposed in order to better identify lesions suitable for ESD. However, case selection is still an issue, since only about 8-10% of dissected lesions are superficially invading cancer and most of cases involve benign or massively invading cancer. In addition, significant differences have been reported between Asian and Western countries in regard to main outcomes, and therefore measures should be adopted as soon as possible to reduce this discrepancy.

Recent Advances in Endoscopy

In this narrative review, invited by the Editors of Gastroenterology, we summarize recent advances in the field of gastrointestinal endoscopy. We have chosen articles published primarily in the past 2-3 years. Although a thorough literature review was performed for each topic, the nature of the article is subjective and systematic and is based on the authors' experience and expertise regarding articles we believed were most likely to be of high clinical and scientific importance.

Clinical outcomes after endoscopic submucosal dissection for colorectal neoplasia: a systematic review and meta-analysis

BACKGROUND AND AIMS

Endoscopic submucosal dissection (ESD) is an endoscopic resection technique for lesions suspicious of superficial malignancy. It is performed using an ESD knife on its own (standard technique) or by the sequential use of a knife and a snare (hybrid technique). The experience with these techniques is different in Asian and non-Asian countries. We performed a systematic review and meta-analysis of available evidence on colorectal ESD.

METHODS

Electronic databases were searched up to August 2016 for studies evaluating R0, en bloc resection, and adverse event rates of both techniques for the treatment of colorectal lesions. Proportions were pooled by a random effects model.

RESULTS

Ninety-seven studies (71 performed in Asia) evaluated the standard technique and 12 studies (7 in Asia) the hybrid technique. The R0 resection rate of the standard technique was 82.9%, and it was significantly lower in non-Asian versus Asian countries: 71.3% versus 85.6%. The en bloc resection rate was 91% and was significantly lower in non-Asian versus Asian countries (81.2% vs 93%, respectively). Surgery was needed in 1.1% of the ESD-related adverse events, with a significant difference between non-Asian and Asian countries (3.1% vs 0.8%). The R0 and en bloc resection rates with the hybrid technique were significantly lower than those achieved with the standard technique: 60.6% and 68.4%, respectively, with similar adverse event rates.

CONCLUSIONS

In non-Asian countries the standard ESD technique is still failing to achieve acceptable levels of performance. The hybrid technique showed low R0 resection rates and should not be considered as an adequate alternative to the standard technique.

Polypectomy and advanced endoscopic resection

Most colorectal cancers evolve from colorectal adenomatous polyps in a pathway known as the adenoma to carcinoma sequence. Early detection and removal of colorectal adenomas can prevent the development of colorectal cancer. The vast majority of these polyps can be resected endoscopically. Advances in endoscopic resection techniques have led to expanded indications for endoscopic polypectomy, whereby giant polyps, scarred lesions and early cancers may be cured. We will outline conventional endoscopic mucosal resection techniques as well as more complex resection methods such as endoscopic submucosal dissection, full thickness resection and the use of combined endoscopic and laparoscopic assisted approaches to resection. We will also explore the role of a virtual multidisciplinary team to aid decision-making when managing large and complex colorectal polyps. This review will provide an update on the endoscopic management of colorectal polyps and highlight exciting new developments in this ever-expanding field.

Management of early colonic neoplasia: where are we now and where are we heading?

There have been considerable advances in the endoscopic treatment of colorectal neoplasia. The development of endoscopic submucosal dissection and full thickness resection techniques is changing the way benign disease and early cancers are managed. This article reviews the evidence behind these new techniques and discusses where this field is likely to move in the future. Areas covered: A PubMed literature review of resection techniques for colonic neoplasia was performed. The clinical and cost effectiveness of endoscopic mucosal resection (EMR) is examined. The development of endoscopic submucosal dissection (ESD) and knife assisted resection is described and issues around training reviewed. Efficacy is compared to both EMR and transanal endoscopic microsurgery. The future is considered, including full thickness resection techniques and robotic endoscopy. Expert commentary: The perceived barriers to ESD are falling, and views that such techniques are only possible in Japan are disappearing. The key barriers to uptake will be training, and the development of educational programmes should be seen as a priority. The debate between TEMS and ESD will continue, but ESD is more flexible and cheaper. This will become less significant as the number of endoscopists trained in ESD grows and some TEMS surgeons may shift across towards ESD.