Master of Science (MS)
Biomedical and Veterinary Medical Sciences - Veterinary Clinical Sciences
Unilateral arytenoid lateralization is a commonly performed surgical treatment for laryngeal paralysis in dogs. It involves fixing the moveable arytenoid cartilage to the thyroid (TAL) or cricoid (CAL) cartilage or both (CTAL). This increases the area of the rima glottidis (RGA), to allow reduced airway pressure and laryngeal resistance in vitro and ameliorates clinical signs in vivo. It may also increase the patient’s predisposition for aspiration pneumonia, which occurs in around 20% of clinical patients. No surgical technique has been correlated with clinical outcome or risk of aspiration pneumonia. Objective analysis of the effects of surgery on the three dimensional structure of the larynx has not been performed. Non-invasive assessment and standardization or classification of arytenoid lateralization techniques would allow more effective prospective clinical trials to identify prognostic factors for outcome and complications. Eight cadaver larynges were secured to radiolucent materials for Computed Tomography (CT) before and after TAL, CAL and CTAL with sutures tensioned to 100g or 500g. Multiple measurements were taken from CT 3D reconstructions of the larynx to assess arytenoid displacement in three separate planes. No significant changes were found for any CT measure except the distance between the arytenoid and thyroid wing (ATW). CTAL at 500g and TAL at 500g showed significantly smaller ATW compared to CAL at 100g suggesting that a high tension TAL or CTAL causes the most lateralization of the arytenoid. CAL may allow reduction in airway pressure without excessive lateralization of the arytenoid. ATW is a candidate for a marker of lateralization of UAL procedures, which could be implemented in future prospective clinical studies. Sequential tensioning and loosening of the suture had no significant effect on any measured parameter validating the use of larynges in sequential measurements.
Document Availability at the Time of Submission
Release the entire work immediately for access worldwide.
Wignall, James Richard, "Computed tomographic assessment of canine arytenoid lateralization" (2013). LSU Master's Theses. 996.