Equine Laryngoplasty Sutures Undergo Increased Loading During Coughing and Swallowing

Abstract

Swallowing increases laryngoplasty suture force to a greater extent than coughing.

A review of equine laryngoplasty complications

“…) and blockade of the recurrent laryngeal nerve did not change the force exerted on LP prostheses during swallowing or coughing (Witte et al . ). In conclusion, there is no evidence that residual laryngeal adductor function influences the long‐term degree of LP abduction.…”

“…Witte et al . () have since demonstrated that the force exerted on the LP prosthesis during swallowing was significantly greater than that exerted during coughing and suggested that normal swallowing causes LP abduction loss. Irrespective of cause, it should be accepted that some post operative loss of LP abduction is inevitable in most horses.…”

“…Additionally, Witte et al . () showed that post operative coughing applies pressure on the laryngoplasty suture which may contribute to failure of the prosthesis/cartilage. Strategies to minimise post operative aspiration in such cases include feeding from the ground, washing the mouth prior to exercise and muzzling horses shortly after feeding and prior to exercise (Hawkins et al .…”

Ex Vivo Mechanical Evaluation of a Sternal ZipFix®Implant for Prosthetic Laryngoplasty in Horses

“…Cyclic loading is a critical step in the mechanical evaluation of materials for prosthetic laryngoplasty. We used a cyclic load comparable to previous reports (25–50 N) for 1,000 cycles to represent the load placed on an implant over the first 24 hours . Distraction distance under cyclic load can be interpreted as a measure of the distance an implant could be expected to loosen when used in vivo.…”

“…Peak load (N) and maximum slope (N/mm) were recorded (Bluehill ® Software, Instron, Norwood, MA). In Experiment 2, arytenoid cartilages (n=6) and cricoid cartilages (n=3) were subjected to a preload of 25 N, then loaded at 25–50 N for 1,000 cycles . Cyclic loading was applied at a distraction rate of 0.83 mm/s, distraction (mm) to maintain load and mean slope (N/mm) were recorded (Bluehill ® Software).…”