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Endoscopy 2020; 52(05): 336-337
DOI: 10.1055/a-1129-7533
Editorial

Colonic endoscopic submucosal dissection – increasing attraction with improved traction?

Referring to Faller J et al. p. 383–388
Andreas Probst
Department of Gastroenterology, University Hospital Augsburg, Germany
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Colonic endoscopic submucosal dissection (ESD) is a challenging procedure involving a learning curve and showing substantial complication rates in unexperienced hands [1]. For this reason, ESD of colonic neoplasms has not become a standard procedure and is still restricted, especially in Western countries, to a few expert centers. Various modifications of the technique have been developed over recent years to overcome technical difficulties, to make ESD easier, and to shorten the learning curve. Key points of the ESD technique are the accessibility of the submucosal layer, which is influenced by the lifting capacity of the submucosal layer (degree of fibrosis), and the traction of the targeted lesion toward the colonic lumen. Consequently, one of the main focuses for modification of the ESD technique has been the development of strategies and devices aimed at improving tissue traction. Modified resection strategies include the optimum use of gravity, tunneling techniques, and pocket creation techniques. In 2002, Oyama et al. first described the clip and line method for esophageal and gastric ESD [2]. After circumferential incision of the target lesion, a hemoclip with a line is fixed at the edge of the lesion, allowing stable access into the submucosal layer. For lesions located in the distal colon and rectum, the double scope technique was introduced by Uraoka et al. in 2007 [3]. The edge of the target lesion is grasped and lifted using a snare or forceps inserted through a second thin endoscope. During subsequent years, several randomized controlled trials were published by Japanese experts investigating different modifications of the clip and line technique (S-O clip method, ring-shaped thread countertraction method, clip and thread method). All studies showed comparable success rates but with significant shortening of the procedure time compared with the standard ESD technique [4]. Nomura et al. described a single-clip traction method in combination with the pocket creation method without using a line [5]. Recently, Jacques et al. presented another innovative technique using two clips and a rubber band to improve countertraction during colonic ESD (DCT-ESD). Compared with the standard ESD technique, a significantly increased en bloc resection rate (95.7 % vs. 76.3 %), R0 resection rate (78.5 % vs. 64.5 %), and speed of dissection (28.2 vs. 16.7 mm2/min) was shown for DCT-ESD in treatment-naïve colorectal lesions [6].

“Double clip with band ESD offers a promising option for residual or locally recurrent colorectal lesions after previous EMR; however, it needs high expertise beyond the ESD learning curve and should be restricted to ESD experts in high-volume centers.”

In this issue of Endoscopy, Faller et al. from the same French group report on 53 residual or locally recurrent (RLR) colorectal lesions after previous endoscopic mucosal resection (EMR), which were treated using the DCT-ESD technique in two French high-volume centers [7]. Overall, 83.0 % of the lesions were located in the cecum, the ascending colon or the transverse colon; rectal lesions were excluded. Impressive results for en bloc resection rate (92.5 %), R0 resection rate (79.2 %), curative resection rate (77.4 %), and median procedure speed (21 mm2/min) were achieved. The R0 resection rate increased from 61.5 % to 96.3 % during the study period. Four intraoperative perforations and one delayed bleeding were successively treated endoscopically. None of the patients had to be treated surgically. The median procedure time was 43 minutes when specimens with a median size of 40 mm were resected. The authors conclude that DCT-ESD is a safe and effective treatment for RLR colonic lesions after EMR.

The results contribute to the literature not only on the technique of colorectal ESD but also on the treatment strategy for difficult-to-treat RLR colorectal lesions. As mentioned by the authors in the discussion section, the results were achieved by four ESD experts who had each performed more than 200 colorectal ESDs before starting the study. Despite this, the R0 rate was 61.5 % in the first half of the study period. The technique offers a promising new treatment option for RLR lesions; however, it needs high expertise beyond the ESD learning curve and should be restricted to ESD experts in high-volume centers. DCT-ESD is another step in the development of the ideal colorectal endoscopic resection method. However, the learning curve of colonic ESD remains the major problem and we still have a long way to go before colonic ESD becomes a standard procedure in Western countries.

The treatment of RLR colonic lesions remains challenging. For treatment-naïve colorectal lesions we have strong evidence and can follow our guideline algorithms to choose the ideal treatment strategy and to select lesions that require ESD [8]. In contrast, treatment decisions for RLR colorectal lesions are not currently standardized. Large studies have demonstrated that endoscopic re-treatment with repeat EMR or ablative techniques is sufficient for the vast majority of RLRs. In the Australian Colonic EMR (ACE) study, 93.1 % of RLR lesions could be treated successfully with snaring techniques in combination with electrocautery or argon plasma coagulation (APC) [9]. The European Society of Gastrointestinal Endoscopy recommends that suspected RLR adenomas should be resected by snare or ablated, and lesions with substantial fibrosis may be suitable for ESD resection [8]. However, the choice of the ideal treatment may be difficult in daily practice, and colonic ESD is currently not widely available in Europe. Endoscopic full-thickness resection (EFTR) is a novel alternative treatment option for colorectal lesions. A German prospective multicenter study showed a promising R0 resection rate of 77.7 % for nonlifting RLR adenomas. However, the R0 resection rate decreased to 58.1 % when the lesion diameter exceeded 20 mm [10]. Randomized trials comparing EFTR with other resection techniques are not yet available.

Ito et al. recently presented a Japanese treatment strategy for RLR colorectal lesions [11]. Treatment decision (cold polypectomy, EMR or ESD) was based on lesions size and the risk of malignancy. EFTR was not included as a treatment option, probably because the technical device is not available in Japan.

Randomized trials are urgently needed to compare different resection methods for colorectal RLRs (EMR, APC, avulsion techniques, EFTR, ESD). It would be desirable to define the lesions that can be treated sufficiently with simple, inexpensive, and widely available techniques, and to define the subgroup of lesions that need to be referred to expert centers offering advanced resection techniques such as ESD or modified ESD (DCT-ESD).

The long-term vision would be further progress in resection techniques (modified, less challenging ESD technique or new developments), which can avoid piecemeal resection at the initial intervention and which make considerations regarding the treatment strategy for RLR lesions unnecessary.



Publication History

Article published online:
22 April 2020

© Georg Thieme Verlag KG
Stuttgart · New York

Refers to:

Endoscopic submucosal dissection with double clip and rubber band traction for residual or locally recurrent colonic lesions after previous endoscopic mucosal resectionEndoscopy 2020; 52(05): 383-388
DOI: 10.1055/a-1104-5210