Large Animal Surgery Resident University of Pennsylvania Kennett Square, Pennsylvania
Comparison of Knot Elongation in Suture Materials Commonly Used for Prosthetic Laryngoplasty and the Effect of Cyanoacrylate. Watkins AR, Ford M, Stefanovski D, Van Eps A, Parente E. University of Pennsylvania, New Bolton Center, Kennett Square, PA.
Left laryngeal hemiplegia causes reduced performance in horses and is treated with prosthetic laryngoplasty. A complication of this procedure is loss of arytenoid abduction. Knot elongation is a possible cause for the loss of abduction that has not been widely investigated. Objectives of this study were to investigate the knot elongation that occurs when square knots made of Fiberwire™ (5 USP), FiberTape™ (2 mm), and Ethibond™ (5 USP) were tied under different loading conditions, cyclically loaded and when cyanoacrylate was applied. In the first phase, knots were tied under 5 N, 10 N, 15 N tension and elongation was measured as change in distance between fixed suture ends from the first to last throw. In the second phase similarly tied knots were cyclically loaded from 25 N to 50 N 1000 times and elongation was measured as change in distance from first cycle to the last. Control lengths of suture without knots were tested. Cyanoacrylate was added to knots before cycling and tested similarly. Ethibond elongated significantly more at 10 N and 15 N than at 5 N. FiberWire and FiberTape showed no significant difference in elongation at varied tensions. Under cyclic loading Ethibond elongated most in control and square knot conditions followed by FiberWire and FiberTape. Addition of cyanoacrylate decreased the elongation of Ethibond but not FiberWire or FiberTape. The results show that Ethibond elongates more than FiberWire or FiberTape but that addition of cyanoacrylate decreases the elongation. This study is limited by the in vitro design. Use of cyanoacrylate should be investigated to decrease loss of abduction.