Surgical advancement of the larynx (laryngeal tie-forward) as a treatment for dorsal displacement of the soft palate in horses: a prospective study 2001-2004

Abstract

Summary Reasons for performing study: Correct placement of sutures (‘laryngeal tie‐forward’) in experimentally created dorsal displacement of the soft palate (DDSP) has been observed to replace the function of the thyrohyoideus muscles and prevent DDSP. Hypothesis: The ‘laryngeal tie‐forward’ procedure would prevent or delay the occurrence of DDSP during exercise in horses with naturally occurring DDSP and therefore improve performance. Methods: A clinical population (n = 116), mainly of racehorses was presented for treatment of naturally occurring exercise‐induced DDSP. All horses underwent the ‘laryngeal tie‐forward’ procedure. The relative position of the thyroid and cricoid cartilage in relation to the caudal aspect of the basihyoid bone was recorded; follow‐up was obtained by telephone communication with trainers, owners and/or referring veterinarians. In addition, a performance index and earnings were determined using race records. Results: Preoperatively, the median distance between the caudal aspect of the basihyoid bone and rostral aspect of the thyroid cartilage was 3.5 cm. Post operatively, the thyroid cartilage was moved a median distance of 4 cm rostrally and the larynx was shown to be in a position more rostral and dorsal than in preoperative radiographs. Of 98 horses for which follow‐up was available, the performance of 87% was classified as improved, 12% as unchanged and 2% as worse. In 20 horses in which the diagnosis had been confirmed by treadmill videoendoscopy, 80% had a significantly increased performance index and earnings (P = 0.007). For the entire population, there was a significant improvement in performance index and earnings after surgery (82%) (P = 0.0001). Conclusions: Placing the larynx in a more rostral and dorsal position may have improved the performance in 80–82% of the horses affected with naturally‐occurring DDSP. Potential relevance: ‘Laryngeal tie‐forward’ is a surgical technique that has a measurable effect on the position of the larynx and offers an alternative therapy for treating horses affected with DDSP. More experience may be needed with this technique prior to its widespread use in horses with a clinical diagnosis of DDSP.

In vitro mechanical evaluation of equine laryngeal tie-forward constructs prepared with different suture materials and placement patterns

“…7 Therefore, the surgical technique used in LTF procedures has been modified since its original description in an effort to increase the mechanical strength of the surgical constructs and avoid surgical failure. 4,8 Rossignol et al 7 have described the use of metallic suture buttons or implants placed on the medial side of the thyroid cartilage to minimize suture pull-through in the thyroid cartilage. However, this modified suture technique has not yet been mechanically compared with the standard technique.…”

“…(Am J Vet Res 2015;76:373-383) tation of thyrohyoideus muscles. 3,4 Although LTF construct failure rate is apparently low (6%), 6 the modes of LTF construct failure in horses with DDSP are still unknown. It is our experience that braided polyester sutures can pull through the thyroid cartilage or break in the immediate postoperative period.…”

“…9 Size-5 braided polyester or polyethylene sutures can be used to perform the LTF procedure in horses with DDSP. 3,4 However, the choice of suture material used may influence the postoperative mechanical properties and failure modes of LTF constructs 9 as well as their biological reactivity. 10,11 A recent investigation 9 of the mechanical properties of LTF surrogate constructs prepared with braided polyester or polyethylene sutures revealed that polyethylene sutures were stronger and stiffer and had less elongation prior to failure, compared with polyester sutures.…”

Evaluation of Overground Endoscopy Findings in Sport and Pleasure Horses

“…The reason why it is so common in racehorses might be that at high galloping speed, there is a higher chance of development of DDSP, due to the increased activity of the muscles that affect the interrelationships between the larynx, the pharynx, and the hyoid apparatus [16]. In such cases of extrinsic origin, tie forward surgery is the suggested choice of treatment [17]. The success rate of this surgery is 68% to 90%, so there is a nonnegligible chance of failure in general [12].…”

The laryngeal tie-forward procedure to alleviate aspiration of feed caused by hypoplasia of the soft palate of an adult mare

“…The laryngeal tie-forward procedure was first described in 2005 as a treatment for horses for 28 obstruction of the airway and decreased performance caused by intermittent dorsal displacement 29 of the soft palate (Woodie et al 2005). Because this procedure advances the larynx rostrally and 30 dorsally, we theorized that this procedure might be beneficial in ameliorating aspiration of feed 31 resulting from a soft palatal defect by decreasing the gap between the soft palate and the 32 epiglottis.…”