Is closure of large mucosal defects after endoscopic mucosal resection and endoscopic submucosal dissection truly needed?

We read with interest the article by Sakamoto et al. [1] on closure of large mucosal defects after endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) for the prevention of complications. Because closure of large mucosal defects is quite difficult with conventional clips, they designed a new closure device, a “loop clip”, which consists of a metal clip attached to a loop of nylon string. After a loop clip was connected to the mid edges of a large mucosal defect, conventional clips were placed to achieve complete closure in three lesions. With a figure-of-8-shaped ring (8-ring) and clips [2], and with an endoloop and clips [3], other endoscopic closure techniques for post-EMR large mucosal defects were also described. We believe that these techniques have some drawbacks, and furthermore, we doubt whether the prophylactic closure could effectively prevent delayed bleeding.

EMR and ESD are indicated for the treatment of large sessile or flat colorectal polyps. Although large polyps have a greater malignant potential, and are traditionally treated surgically, EMR and ESD are preferable to surgery because the techniques have potential to cure and are less invasive [4] [5]. On the basis of the size and location of the polyps, EMR can be performed en bloc or piecemeal. Although piecemeal resection is related to a higher recurrence rate compared with en bloc resection, the piecemeal technique is used most frequently in large polyps [4] [6]. Recently, ESD by experienced hands enabled en bloc resection, regardless of tumor size, with a higher rate of radical cure but also complications compared with EMR [6]. We believe that closure techniques would cover not only large mucosal defects but residual polyp tissue, resulting in a delay of adequate treatment for the recurrence [4].

The risk of post-EMR bleeding and perforation is reported to increase with the size of the polyps resected [2]. Although Sakamoto et al. [1] recommended prophylactic clipping closure of the mucosal defects after EMR and ESD for the prevention of bleeding and perforation, the clipping technique has not decreased the occurrence of delayed bleeding in a prospective randomized controlled study [7]. Most perforations are small enough to close with immediate clipping [8], and their preliminary results of the loop clip-assisted complete closure of mucosal defects would be useful for perforations too large to close with a simple closure, as they suggested. If their excellent technique cannot reduce the complication rate, we believe that the closure technique might be only more time-consuming than EMR and ESD without closure.

Competing interests: None

References

• 1 Sakamoto N, Beppu K, Matsumoto K. et al . “Loop Clip”, a new closure device for large mucosal defect after EMR and ESD.  Endoscopy. 2008;  40 DOI 10.1055/s-2007-995604
• 2 Fujii T, Ono A, Fu K I. A novel endoscopic suturing technique using a specially designed so-called “8-ring” in combination with resolution clips (with videos).  Gastrointest Endosc. 2007;  66 1215-1220
• 3 Matsuda T, Fujii T, Emura F. et al . Complete closure of a large defect after EMR of a lateral spreading colorectal tumor when using a two-channel colonoscope.  Gastrointest Endosc. 2004;  60 836-838
• 4 Brooker J C, Saunders B P, Shah S G. et al . Treatment with argon plasma coagulation reduces recurrence after piecemeal resection of large sessile colonic polyps: a randomized trial and recommendations.  Gastrointest Endosc. 2002;  55 371-375
• 5 Matsushita M, Hajiro K, Takakuwa H. et al . Which parameter, marginal irregularity or tumor size, is more closely related to a malignant potential in flat elevated type of colorectal tumor?.  Gastrointest Endosc. 1999;  50 306-307
• 6 Tanaka S, Oka S, Kaneko I. et al . Endoscopic submucosal dissection for colorectal neoplasia: possibility of standardization.  Gastrointest Endosc. 2007;  66 100-107
• 7 Shioji K, Suzuki Y, Kobayashi M. et al . Prophylactic clip application does not decrease delayed bleeding after colonoscopic polypectomy.  Gastrointest Endosc. 2003;  57 691-694
• 8 Taku K, Sano Y, Fu K I. et al . Iatrogenic perforation associated with therapeutic colonoscopy: a multicenter study in Japan.  J Gastroenterol Hepatol. 2007;  22 1409-1414