University of Pennsylvania School of Veterinary Medicine, George D. Widener Hospital for Large Animals, Kennett Square, Pennsylvania 19348, USA.
Equine Vet J. 2011 Mar;43(2):229-34. doi: 10.1111/j.2042-3306.2010.00070.x.
Loss of arytenoid abduction is a common post operative complication of laryngoplasty without a definitive cause. It has been a clinical impression during laryngoplasty surgery that there is great conformational variability along the caudal edge of the Thoroughbred cricoid cartilage that could impact post operative retention of suture position. A change in suture position would probably lead to some loss of abduction. Defining any structural variability of the cricoid would be an initial step in determining whether this variability could impact on the retention of suture position.
Anatomical variations in the larynx of Thoroughbred horses may be detected and measured using objective analysis and computed tomography.
Larynges were harvested from 15 mature Thoroughbred horses. Helical CT scans were performed on each specimen. Three independent observers performed a series of measurements on 2D and 3D reconstruction images using digital software. Measurements included the lateral cricoid angle, the caudal cricoid prominences, the distance to the cricoid slope, the angle of the cricoarytenoid joints (CAJ), the cricoid thickness and the suture angle. Mean, standard deviation, coefficient of variation and linear regression analysis were performed among all observers and all measurements.
Notable conformational differences were evident on the 3D reconstructions. The highest degree of variability was found in 3 measurements: the distance to the lateral cricoid slope, the lateral cricoid angle and the cricoid thickness. A larger left CAJ angle directly and significantly correlated with a larger suture angle.
There are notable conformational differences among cricoid specimens in the Thoroughbred larynx.
The morphometric differences identified may impact on optimal prosthesis placement and long-term retention. Since a larger lateral cricoid angle may facilitate abduction loss secondary to a displaced and loosened suture, alternative techniques for suture placement may be of value to prevent arytenoid abduction loss.
杓状软骨不内收是喉成形术后的常见并发症，但无明确病因。在喉成形术中的临床印象是，种马环状软骨的尾部边缘存在很大的形态变化，这可能影响缝线位置的术后保留。缝线位置的变化可能导致某些外展的丧失。确定环状软骨的任何结构变化将是确定这种可变性是否会影响缝线位置保留的初始步骤。
可以使用客观分析和计算机断层扫描来检测和测量纯种马的喉部解剖结构变化。
从 15 匹成熟的纯种马中采集喉。对每个标本进行螺旋 CT 扫描。三位独立观察者使用数字软件对 2D 和 3D 重建图像进行了一系列测量。测量包括环状软骨外侧角、环状软骨后突、到环状软骨斜坡的距离、环杓关节（CAJ）角度、环状软骨厚度和缝线角度。对所有观察者和所有测量值进行平均值、标准差、变异系数和线性回归分析。
3D 重建图像上显示出明显的形态差异。在 3 个测量值中发现了最大的变异性：到环状软骨外侧斜率的距离、环状软骨外侧角和环状软骨厚度。左侧 CAJ 角度越大，缝线角度越大。
在纯种马的喉部，环状软骨标本之间存在明显的形态差异。
鉴定出的形态差异可能会影响最佳假体放置和长期保留。由于较大的外侧环状软骨角可能会导致缝线移位和松动导致的外展丧失，因此替代缝线放置技术可能具有防止杓状软骨外展丧失的价值。
