Experience with a new device for pathological assessment of colonic endoscopic submucosal dissection

Comparison of two pathological processing methods for large endoscopic submucosal dissection (ESD) specimens

AIMS

Accurate histopathological evaluation of the endoscopic submucosal dissection (ESD) specimens is essential for clinicians to guide further triage and management. This study aimed to report a novel processing technique for large ESD (≥4 cm) specimens.

METHODS

92 patients with colorectal neoplasms who had undergone ESD were included. 46 ESD specimens were treated with conventional handling process, while the rest 46 cases were given the optimised method. Macrobiocassettes and L-shaped embedding moulds were applied in the optimised method. We evaluated the efficacy of this improved procedure in terms of the number of paraffin blocks, storage space and time consumption of pathological assessment.

RESULTS

The average diameter of ESD specimens was 4.5±0.4 cm and 4.7±0.5 cm in the control and test group (p=0.023), respectively. In control group, 398 paraffin blocks of 46 cases were obtained. With the same cases number and larger lesion size, only 276 blocks were achieved in test group (p<0.001). As for the storage space, the total volume of paraffin blocks and slides (4554.0 cm3 and 1207.5 cm3) of optimised method was significantly reduced compared with the control group (6208.8 cm3 and 1741.3 cm3) (p=0.001, p<0.001). In addition, the optimised method was superior to the conventional one in shortening time consumption of pathological assessment (164.5 min and 269.0 min, p<0.001).

CONCLUSIONS

The optimised technique not only reduced the workload and storage space, but also facilitated accurate pathological assessment.

Optimal processing of ESD specimens to avoid pathological artifacts

BACKGROUND

En bloc endoscopic submucosal dissection (ESD) has been recently introduced as a treatment for precancerous/neoplastic gastrointestinal conditions. The aim of the present study was histological assessment of en bloc ESD specimens.

METHODS

Fifty-three ESD specimens were positioned over a cellulose acetate support (40 specimens; 12 from the upper gastrointestinal tract and 28 from the lower gastrointestinal tract) or pinned with nails on polystyrene or cork (13 specimens; 7 from the upper gastrointestinal tract and 6 from the lower gastrointestinal tract). We cut consecutive 2 mm-thick sections stained with hematoxylin and eosin. From the first and the last sections, we obtained a second slide, after a 180° rotation and re-embedding. The quality of ESD samples was scored as inadequate, suboptimal and adequate, based on the amount of crushing, shearing and stretching artifacts that were scored from 0 (absent) to 2 (diffuse or maximum). From the sum of these we obtained a global artifact score (GAS).

RESULTS

Removed lesions were: adenocarcinoma (5 cases), neuroendocrine tumor (NET) G1 (1 case), premalignant conditions, including adenomatous polyps (41 cases) and hyperplastic lesions (6 cases). A positive deep surgical margin was found in 8/53 cases (15%): high- and low-grade dysplastic glands were detected in 5 cases, low-grade adenocarcinoma in 2, and NET cells in 1. Dysplastic glands were detected in the lateral surgical margins of 12 ESD specimens (23%). Among the ESD specimens positioned on the cellulose acetate support, apart from the modifications due to electrocoagulation, 2 (5%) showed shearing modifications. In the group of ESD specimens fixed with nails, 5 (38%) showed shearing, 10 (77%) crushing artifacts, 11 (85%) stretching and 11 (85%) multiple holes caused by the nails. On the basis of these data all histological specimens from ESD on cellulose acetate were adequate (GAS 0-1).However, in the group of ESD fixed with nails, 1 was adequate (GAS 0), 11 suboptimal (GAS 2-5) and 1 inadequate (GAS 6).

CONCLUSIONS

Specific devices including cellulose support and adequate sampling blocks can be helpful to perform accurate histological assessment of ESD specimens after en bloc ESD for precancerous/neoplastic gastrointestinal lesions, with complete analysis of the status of the margins and the entirely en bloc evaluation of the lesion.

Why attempt en bloc resection of non-pedunculated colorectal adenomas? A systematic review of the prevalence of superficial submucosal invasive cancer after endoscopic submucosal dissection

OBJECTIVE

Endoscopic submucosal dissection (ESD) aims to achieve en bloc resection of non-pedunculated colorectal adenomas which might be indicated in cases with superficial submucosal invasive cancers (SMIC), but the procedure is time consuming and complex. The prevalence of such cancers is not known but may determine the clinical necessity for ESD as opposed to the commonly used piecemeal mucosal resection (endoscopic mucosal resection) of colorectal adenomas. The main aim was to assess the prevalence of SMIC SM1 (ie, invasion ≤1000 µm or less than one-third of the submucosa) on colorectal lesions removed by ESD.

DESIGN

A literature review was conducted using electronic databases (up to March 2017) for colorectal ESD series reporting the histology of the dissected lesions.

RESULTS

51 studies with data on 11 260 colorectal dissected lesions were included. Most resected lesions (82.2%; 95% CI 78.8% to 85.3%) were adenomas (low- and high-grade dysplasia, 26.8% and 55.4%, respectively). Overall, 15.7% were submucosal cancers, but only slightly more than half (8.0%; 95% CI 6.1% to 10.3%) had an infiltration depth of ≤1000 µm, providing a number needed to treat (NNT) to avoid one surgery of 12.5. Estimating an oncologically curative (R0; G1/2; L0/V0) resection rate of 75.3% (95% CI 52.2% to 89.4%) for malignant lesions, the prevalence of curative resection lowered to 6% (95% CI 4.2% to 7.2%) with an NNT of 16.7.

CONCLUSION

The low prevalence of SMIC SM1 in lesions selected for ESD as well as the even lower rate of curative resection limits the clinical applicability of endoscopic en bloc resection. This calls for caution over an indiscriminate use of this technique in the resection of colorectal neoplasia.

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.

Colorectal endoscopic submucosal dissection: a systematic review and meta-analysis

Background and study aims: Endoscopic submucosal dissection (ESD) is an advanced endoscopic technique that allows en-bloc resection of gastrointestinal tumor. We systematically review the medical literature in order to evaluate the safety and efficacy of colorectal ESD. Patients and methods: We performed a comprehensive literature search of MEDLINE, EMBASE, Ovid, CINAHL, and Cochrane for studies reporting on the clinical efficacy and safety profile of colorectal ESD. Results: Included in this study were 13833 tumors in 13603 patients (42 % female) who underwent colorectal ESD between 1998 and 2014. The R0 resection rate was 83 % (95 % CI, 80 - 86 %) with significant between-study heterogeneity (P < 0.001) which was partly explained by difference in continent (P = 0.004), study design (P = 0.04), duration of the procedure (P = 0.009), and, marginally, by average tumor size (P = 0.09). Endoscopic en bloc and curative resection rates were 92 % (95 % CI, 90 - 94 %) and 86 % (95 % CI, 80 - 90 %), respectively. The rates of immediate and delayed perforation were 4.2 % (95 % CI, 3.5 - 5.0 %) and 0.22 % (95 % CI, 0.11 - 0.46 %), respectively, while rates of immediate and delayed major bleeding were 0.75 % (95 % CI, 0.31 - 1.8 %) and 2.1 % (95 % CI, 1.6 - 2.6 %). After an average postoperative follow up of 19 months, the rate of tumor recurrence was 0.04 % (95 % CI, 0.01 - 0.31) among those with R0 resection and 3.6 % (95 % CI, 1.4 - 8.8 %) among those without R0 resection. Overall, irrespective of the resection status, recurrence rate was 1.0 % (95 % CI, 0.42 - 2.1 %). Conclusions: Our meta-analysis, the largest and most comprehensive assessment of colorectal ESD to date, showed that colorectal ESD is safe and effective for colorectal tumors and warrants consideration as first-line therapy when an expert operator is available.

How to deal with large colorectal polyps: snare, endoscopic mucosal resection, and endoscopic submucosal dissection; resect or refer?

PURPOSE OF REVIEW

The importance of accurate polyp detection and removal is paramount to preventing colon cancer. Resection of large polyps can be challenging to the endoscopist based on their size, shape, or location. Large polyps have the potential of harboring malignancy and a higher risk of complications with resection. Careful assessment of each lesion and meticulous resection using the appropriate tools and techniques is essential.

RECENT FINDINGS

Over the last 15 years, the development of endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) techniques has presented the endoscopist with the opportunity to manage patients with large and flat lesions thereby avoiding the need for surgery. However, these techniques are complex and require extensive knowledge and skill in the use of various devices to resect a lesion completely and manage bleeding and perforation associated with these procedures.

SUMMARY

Large colon polyps manifest as either polypoid or nonpolypoid (flat) lesions. Polypoid lesions, especially those with pedicles, are removed with snare resection, whereas flat lesions may require the use of EMR or ESD. Resection of large polyps (>1 cm) requires additional tools and techniques to ensure safe and complete resection. We will discuss our approach to dealing with large colorectal polyps: snare, EMR, and ESD; resect or refer?