Assessing the adequacy of endoscopically tied knots: A functional approach

B. Hu, L. C.L. Sun, M. Karmakar, P. B. Cotton, C. J. Gostout, R. H. Hawes, A. N. Kalloo, S. V. Kantsevoy, P. J. Pasricha, Sydney C.S. Chung

Research output: Contribution to journalArticlepeer-review

3 Scopus citations


Background and study aims: Endoscopic intracorporeal knots have potentially enormous applications in endoscopic surgery. We describe a method for testing the security of various types of endoscopically tied knots using a vessel perfusion manometer system. Methods: A 4-cm segment of porcine splenic artery was placed on the mucosal surface of a pig stomach. The two ends of the vessel were brought out through the gastric wall and connected to a two-way manometer. One end was also joined to a pressure infusion bag. The stomach was mounted in an Erlangen training model. A long 3/0 nylon thread, previously introduced into the submucosal layer of the stomach and encircling the vessel, was brought out from the mouth. Three-throw square knots, Mayo knots, "surgeon's" knots and five-throw square knots were tied and pushed into place using a cap attached to a gastroscope. The pressure at the two ends of the artery was compared. If the pressure could be increased to over 200 mm Hg at one end without a change in the other, the knot was considered secure. Results: Each type of knot was tested 12 times under endoscopic vision. The range for mean knotting time was 3.4-4.5 minutes. Five-throw knots took significantly longer to tie than three-throw knots (P < 0.005). There was one loose knot in each of the three-throw and Mayo groups, and three each in the "surgeon's" and five-throw groups (P > 0.05). Conclusions: This system is a reliable model for testing intracorporeal knots tied endoscopically. A three-half-hitches square knot with 3/0 nylon, tied using a flexible endoscope and knot-tightening cap, can withstand pressure up to 200 mm Hg.

Original languageEnglish (US)
Pages (from-to)415-417
Number of pages3
Issue number5
StatePublished - May 2005

ASJC Scopus subject areas

  • Gastroenterology


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