STEVEN M. ZEITELS, MD BOSTON, MASSACHUSETTS
ILAN HOCHMAN, MD TEL AVIV, ISRAEL
ROBERT E. HILLMAN, PHD BOSTON, MASSACHUSETTS
Arytenoid adduction was designed to enhance posterior glottal closure
in patients with paralytic dysphonia by reproducing lateral cricoarytenoid
muscle function. However, this procedure can exaggerate normal medial
rotation of the vocal process, because the agonist-antagonist function
of the interarytenoid,
lateral thyroarytenoid, and posterior cricoarytenoid muscles is not
simulated. Therefore, a new adduction procedure (adduction arytenopexy)
was devised
to affix the arytenoid on the cricoid facet in a more optimal position
for glottal sound production. The adduction arytenopexy procedure
was designed on fresh cadavers. In this technique, the lateral aspect of
the cricoarytenoid
joint is opened widely and the body of the arytenoid is manually
medialized along the cncoid facet. A specially designed single suture is
then placed
through the posterior cricoid and the body or the muscular process
of the arytenoid to achieve 2-point fixation. This draws the arytenoid
posteriorly,
superiorly, and medially for precise positioning. The arytenoid is
rocked internally on the cricoid facet, and suture tension is adjusted
appropriately
to simulate normal cricoarytenoid adduction. In the first study,
the adduction arytenopexy was compared with the classic arytenoid adduction
in 10 fresh
cadaver larynges. The new arytenopexy procedure resulted in an average
increase of 2.1 mm(p <.01) in the length of the musculomembranous vocal
fold, whereas the classic arytenoid adduction did not reveal a significant
change in length. Additionally, the adduction arytenopexy resulted
in a consistently higher vocal fold and a more normally contoured arytenoid
than the classic adduction procedure. The second study consisted
of a clinical
trial in which 12 patients, who presented with a widely patent posterior
glottis, underwent adduction arytenopexy in conjunction with implant
medialization. The procedure was successful in all patients, and there
were minimal complications.
In the third study, preoperative and postoperative vocal assessment
measures (stroboscopic, aerodynamic, acoustic, and perceptual) were analyzed
in
9 of the 12 patients. The most striking preoperative stroboscopic
observation was that 8 of the 9 patients presented with an aperiodic vibrational
flutter
during phonation due to severe valvular incompetence. Postoperatively,
all patients developed complete closure of the glottal chink and
effective entrained oscillation of the vocal folds. This visual improvement
in function
was commensurate with comparable changes in most of the other objective
and subjective measures of vocal function. The new adduction arytenopexy
procedure closely simulates the biomechanics underlying normal glottal
closure and cricoarytenoid adduction. In turn, complex implant design
shapes are not necessary to achieve proper alignment of the arytenoid and
the
vocal fold. Because the arytenoid is properly positioned prior to
the medialization, implants can be sized more precisely and are unencumbered
by an anterior
thyroid lamina suture. These procedural innovations resulted in enhanced
entrained oscillation of the glottal valve and, in turn, improved
laryngeal sound production.
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