Double-tunnel method for treatment of colorectal lesions with severe fibrosis with endoscopic submucosal dissection

Endoscopic submucosal dissection (ESD) for gastrointestinal lesions enables en bloc resection with tumor-free margins and is not limited by the lesion size or location. However, en bloc removal of colorectal lesions with severe fibrosis is difficult and requires a longer time [1] [2]. We report the successful resection of an early rectal tumor by colorectal ESD with a new method: double-tunnel ESD.

A 68-year-old man was referred to our hospital for treatment of a large sub-protruded rectal lesion measuring about 60 mm in diameter ([Fig. 1 a]). He underwent ESD, which was performed using a dual knife (KD-650U; Olympus, Tokyo, Japan), with the patient under deep sedation.

Fig. 1 Endoscopic images showing: a a protruded lesion in the rectum (60 mm in size) on retroflexed view; b the entrance of the first tunnel at the anal site (yellow arrow); c the remaining side of lesion on retroflexed view; d the appearance after completion of submucosal dissection, which was achieved with no muscle injury.

Our plan to achieve en bloc resection of this large sub-protruded lesion, a type of lesion that often has severe fibrosis or displays the muscle-retracting sign during ESD [3], was first to open two different tunnels on each side of the severe fibrosis from the anal side of the lesion ([Fig. 1 b]). This technique allows good traction to be maintained and an appropriate dissection line to be identified, even in the presence of severe fibrosis. Subsequently, the two tunnels were connected ([Video 1]). Finally, mucosal and submucosal dissections were performed from both sides to open the lesion from the lower side against gravity ([Fig. 1 c]). After this, the lesion was completely resected en bloc without any complications ([Fig. 1 d]). The tumor was 59 × 50 mm in size; histological examination revealed a submucosally invasive carcinoma, with all the margins being tumor-free ([Fig. 2]).

Video 1 Colorectal endoscopic submucosal dissection with the double-tunnel method is used to resect a lesion with severe fibrosis efficiently and safely because good traction is maintained and an appropriate dissection line can be identified.

Fig. 2 The opened specimen revealed submucosally invasive carcinoma, with negative margins, measuring 59 × 50 mm.

ESD using the double-tunnel method can achieve reliably efficient and safe resection of colorectal lesions with severe fibrosis or displaying the muscle-retracting sign.

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Competing interests

None

• References

• 1 Matsumoto A, Tanaka S, Oba S. et al. Outcome of endoscopic submucosal dissection for colorectal tumors accompanied by fibrosis. Scand J Gastroenterol 2010; 45: 1329-1337
• 2 Chiba H, Tachikawa J, Kurihara D. et al. Safety and efficacy of simultaneous colorectal ESD for large synchronous colorectal lesions. Endosc Int Open 2017; 5: E595-E602
• 3 Toyonaga T, Tanaka S, Man-I M. et al. Clinical significance of the muscle-retracting sign during colorectal endoscopic submucosal dissection. Endosc Int Open 2015; 3: E246-E251