Reply to the letter by Coriat et al.

We sincerely thank Dr Coriat and colleagues for their comments on our article entitled “Transmural air leak”: a computed tomographic finding following endoscopic submucosal dissection of gastric tumors [1].

Despite the promising application of endoscopic submucosal dissection (ESD) for colorectal tumors, a substantial risk of procedure-related perforation has been reported due to the thin wall and sparse muscle layer in this part of the gastrointestinal tract. Actually, the perforation rate ranges from 2.2 % to 8.2 % in colorectal ESD [2] [3] [4] [5].

Coriat et al. stated that transmural air leak was observed in their patients undergoing rectal ESD. We also noted transmural air leak (pneumoretroperitoneum and pneumoperitoneum) by abdominal computed tomography (CT) after colorectal ESD in 39 of 196 consecutive patients (19.9 %) [6], giving a similar incidence to that in gastric ESD (13 %) [1]. The transmural air leak was observed in patients in whom the procedure time was longer, but abdominal pain or symptoms of peritonitis were not observed, except for a higher incidence of pyrexia above 37.5 ° C. The patients with pyrexia were treated with antibiotics and all of them recovered following this conservative treatment.

Thus, we agree with Coriat et al. that it is less necessary to systematically perform CT scans in patients without clinical symptoms after gastric or colorectal ESD. In patients with pyrexia, CT would help to distinguish transmural air leak from other complications that possibly require urgent intervention.

Competing interests: None

References

• 1 Onogi F, Araki H, Ibuka T. et al . “Transmural air leak”: a computed tomographic finding following endoscopic submucosal dissection of gastric tumors.  Endoscopy. 2010;  42 441-447
• 2 Saito Y, Uraoka T, Matsuda T. et al . Endoscopic treatment of large superficial colorectal tumors: a case series of 200 endoscopic submucosal dissections (with video).  Gastrointest Endosc. 2007;  66 966-973
• 3 Isomoto H, Nishiyama H, Yamaguchi N. et al . Clinicopathological factors associated with clinical outcomes of endoscopic submucosal dissection for colorectal epithelial neoplasms.  Endoscopy. 2009;  41 679-683
• 4 Niimi K, Fujishiro M, Kodashima S. et al . Long-term outcomes of endoscopic submucosal dissection for colorectal epithelial neoplasms.  Endoscopy. 2010;  42 723-729
• 5 Toyonaga T, Man-i M, Fujita T. et al . Retrospective study of technical aspects and complications of endoscopic submucosal dissection for laterally spreading tumors of the colorectum.  Endoscopy. 2010;  42 714-722
• 6 Araki H, Horibe Y, Onogi F. et al . Pneumoretroperitoneum and pneumoperitoneum detected by CT after endoscopic submucosal dissection for colorectal tumors in consecutive cases [abstract].  Gastrointest Endosc. 2010;  71 AB337