Transmural air leak following endoscopic submucosal dissection: a non-useful computed tomography finding

We read with great interest the recent article by Onogi et al. [1], which reported the “transmural air leak” incidence in patients undergoing endoscopic submucosal dissection (ESD) of a gastric lesion. Their conclusions are an important contribution to promote ESD as a treatment in gastric lesions. The authors showed, in a large consecutive series, an excellent low rate of endoscopically visible perforation during ESD (0.8 %) but a high transmural air leak rate (13 %). Air leak incidence was higher in cases where resection size was large, or the procedure duration had been prolonged.

ESD was introduced with the intention of overcoming some of the limitations of endoscopic mucosal resection (EMR). Thus, ESD was developed for use in gastric lesions [2] [3], and recently, ESD has been carried out on large colonic lesions [4]. We agree with Onogi et al. that compared with EMR, ESD has major advantages by enabling “en bloc” resection of the target lesion regardless of its size and location [2] [3] [5] [6]. The incidence of perforation during ESD has been reported in up to 6.1 % of procedures. Many reports agree that surgical treatment of ESD-related perforations can be avoided by immediately closing the hole with endoclips, which is in accordance with treatment of iatrogenic perforations reported with colonic mucosectomy [7] [8].

Our recent findings therefore correlate with those of Onogi et al. in all lesions removed using ESD. In our tertiary endoscopy unit, we performed ESD on 18 patients with large rectal lesions in order to avoid surgery. ESD is a difficult technique that takes extended time, and needs adequately trained endoscopists. In our institution, colonic lesions removed by ESD are performed by trained endoscopists. In this series of 18 patients, transmural air leak was also diagnosed by CT scan post-ESD ([Fig. 1]). As found by Ogoni et al., no patient with transmural air leak in our series developed evidence of peritonitis or severe abdominal pain.

Fig. 1 Computed tomography performed in a patient undergoing colonic endoscopic submucosal dissection. Visualization of a transmural air leak (arrow).

ESD procedures, by definition, involve the dissection of the submucosal layer. The stomach is a sac-like organ with a relatively strong muscular wall, but the muscularis mucosa in the rectum is thinner. Thus, transmural air leak incidence following colonic ESD might be more than 13 %; however this is exclusively a radiological finding and should not be used to modify our clinical management of patients or modify their hospital stay. Taking this into consideration, we consider that abdominal CT imaging should not be systematically performed in patients undergoing gastric or colonic ESD if they have no clinical symptoms post-ESD.

Competing interests: None

References

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