Effect of surgery on the susceptibility of single permeabilized muscle fibers of congenitally‐clefted goat palates to contraction‐induced injury

Abstract

Despite efforts to surgically repair cleft palates, 15% of patients develop velopharyngeal inadequacy (VPI). The hypothesis tested was that cleft palates contain muscle fibers susceptible to contraction-induced injury and that the surgical realignment of these fibers to simulate the normal orientation reduces that susceptibility. Single permeabilized levator veli palatini muscle fibers were isolated from normal and cleft palates of young (2-month-old) goats and normal, cleft, and cleft-palate-repaired palates of adult (8–14-month-old) goats. Surgical repair of the cleft palate consisted of the von Langenbeck technique with intravelar veloplasty at 2 months of age. Following a single lengthening contraction to each fiber (n = 4–15/group), the contraction-induced force deficit was calculated as the loss in force expressed as a percentage of initial force. For young goats, no differences in force deficits were observed between fibers of cleft (37 ± 2%) and normal (44 ± 5%) palates. For adult goats, force deficits of fibers for cleft palates, 40 ± 1%, were twofold greater (P<0.001) than those of normal and cleft-palate-repaired palates, 23 ± 1% and 16 ± 3%, respectively. The careful realignment of muscle fibers during repair surgery may decrease the susceptibility to injury and to VPI. P30 AG 13283