Transluminal closure for NOTES: an ex vivo study comparing leak pressures of various gastrotomy and colotomy closure...

Transluminal closure is fundamental to the safe introduction of natural orifice transluminal endoscopic surgery (NOTES) into humans. Suture, staples, and clips have been used. We aimed to evaluate the acute strength of various gastrotomy and colotomy closure techniques in an ex vivo porcine model by assessing air leak pressures.

The following closure modalities were assessed with at least five samples per arm: conventional open/laparoscopic suturing techniques including full-thickness interrupted sutures, double-layer sutures, and purse-string sutures, as well as endoscopic clips and endoscopic staples. Historical values for transgastric closures with hand-sewn interrupted sutures, endoscopic clips, and a prototype endoscopic suture device were used from our laboratory's prior study.

Using Kruskal-Wallis analysis, the overall comparisons were significant ( P = 0.0038 for gastrotomy closure; P = 0.0018 for colotomy closure). Post hoc paired comparisons revealed that the difference between all closure arms versus negative control were significant. Significance could not be established among the various closure arms. However, trends suggested hand-sewn double-layer sutures, endoscopic staples, and both hand-sewn and endoscopically-placed purse-string sutures produced the strongest closures. Furthermore, endoscopic clips appeared sufficient for colotomy closure when ideally placed.

Suture (both hand-sewn and endoscopically deployed) appears to produce the strongest closures in both stomach and colon, with the important caveats that (1) a continuous through-thickness suture track be avoided, such as in the full-thickness closure, or (2) suture holes be buried, such as in the purse-string configuration. When suture tracks are full-thickness, they can serve as leak sites. Staples and clips can produce comparable closures, but only under ideal conditions.