OBJECTIVE To biomechanically compare modified and standard laryngoplasty constructs in monotonic load to failure and cyclic loading.
SAMPLES 41 equine cadaveric larynges.
PROCEDURES Laryngoplasty constructs were created by use of a standard technique on one side and a modified technique (with a toggle to anchor suture to the arytenoid cartilage) on the other side. For monotonic loading, laryngoplasty constructs were prepared and suture ends attached to a load frame; constructs then were loaded until mechanical failure. Mean load at failure and failure modes were compared between constructs. For cyclic loading, arytenoid cartilages were maximally abducted and constructs were circumferentially loaded for 10,000 cycles. Loss of arytenoid abduction was evaluated every 500 cycles with a subjective grading scale and objective change in rima glottidis cross-sectional area.
RESULTS In monotonic loading, modified laryngoplasty constructs failed at a significantly higher mean ± SD load (191 ± 29 N) than did standard laryngoplasty constructs (91 ± 44 N). None of the modified laryngoplasty constructs failed by suture pull-through of the muscular process of the arytenoid cartilage, whereas most of the standard laryngoplasty constructs failed in that manner. In cyclic testing, 11 of 20 standard laryngoplasty constructs failed or achieved Dixon grade 3 abduction, whereas 0 of 20 modified laryngoplasty constructs failed. Modified laryngoplasty constructs lost significantly less rima glottidis cross-sectional area in circumferential testing, compared with loss for standard laryngoplasty constructs.
CONCLUSIONS AND CLINICAL RELEVANCE The modified laryngoplasty technique was biomechanically superior to the standard laryngoplasty technique in this ex vivo study.
OBJECTIVE To compare the mechanical properties of laryngeal tie-forward (LTF) constructs prepared with different suture materials and suture placement patterns during single load to failure testing.
SAMPLE Larynges harvested from 50 horse cadavers and 5 intact horse cadavers.
PROCEDURES In vitro LTF constructs were created by a standard technique with polyester sutures, a standard technique with polyethylene sutures, a modified technique with metallic implants and polyester sutures, a modified technique with metallic implants and polyethylene sutures, or a modified tie-off technique with polyester sutures (10 of each type of construct). Mechanical properties including maximal load (N) at failure and failure mode were compared among constructs. Also, maximal loads at failure of the in vitro LTF constructs were compared with the loads exerted on the sutures tightened to achieve rostral laryngeal advancement in intact cadavers.
RESULTS Constructs prepared by a standard technique with polyethylene sutures had a significantly higher pull out strength than those prepared by a modified technique with metallic implants and either polyester or polyethylene sutures. For constructs prepared by a standard technique with polyethylene sutures or similarly placed polyester sutures, maximal load at failure did not differ but the failure mode did differ significantly. The load to failure for all in vitro constructs was higher than the maximal load measured during a range of motion test in intact horse cadavers.
CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that LTF procedures can be performed in live horses with any of the suture materials and techniques tested.
Objective—To compare the mechanical properties of laryngeal tie-forward (LTF) surrogate constructs prepared with steel fixtures and No. 5 braided polyester or braided polyethylene by use of a standard or a modified suture placement technique.
Sample—32 LTF surrogate constructs.
Procedures—Surrogate constructs were prepared with steel fixtures and sutures (polyester or polyethylene) by use of a standard or modified suture placement technique. Constructs underwent single-load-to-failure testing. Maximal load at failure, elongation at failure, stiffness, and suture breakage sites were compared among constructs prepared with polyester sutures by means of the standard (n = 10) or modified (10) technique and those prepared with polyethylene sutures with the standard (6) or modified (6) technique.
Results—Polyethylene suture constructs had higher stiffness, higher load at failure, and lower elongation at failure than did polyester suture constructs. Constructs prepared with the modified technique had higher load at failure than did those prepared with the standard technique for both suture materials. All sutures broke at the knot in constructs prepared with the standard technique. Sutures broke at a location away from the knot in 13 of 16 constructs prepared with the modified technique (3 such constructs with polyethylene sutures broke at the knot).
Conclusions and Clinical Relevance—Results suggested LTF surrogate constructs prepared with polyethylene sutures or the modified technique were stronger than those prepared with polyester sutures or the standard technique.