Reversibility of Medialization Laryngoplasty an Experimental Study

Abstract

Medialization laryngoplasty has become a routine procedure for cases of unilateral vocal fold paralysis. In certain clinical situations, it may become desirable to reverse the procedure and remove the implant. This process was studied experimentally in eight dogs in a chronic model of induced canine phonation. A silicone polymer implant was inserted to medialize one normal vocal fold for a period of 1 month, after which it was removed. Motion of the cricoarytenoid (CA) joint and induced phonation were studied weekly while the implant was in place, and for another month following implant removal. Significant abnormalities were found even with this relatively short period of implantation. With the implant in place, impairment of CA joint mobility was found in seven of the eight dogs, precluding phonation. A dense fibrous capsule rapidly developed around the implant, making its removal technically difficult. Following implant removal, a gradual return to normal function was found in only three of the eight dogs. One of the animals had evidence of neural injury, while four had intact neural function but impaired mobility or fixation of the CA joint. Medialization laryngoplasty should not be considered a reversible procedure. The clinical implications of these findings are discussed.

Polydimethylsiloxane versus polytetrafluoroethylene for vocal fold medialization: Histologic evaluation in a rabbit model

“…Some authors 47,50 have reported a major fibrous reaction in the silicone implants as well, and attribute it to the greater stability and lesser degree of displacement of the implant. No signs of malignant degeneration were observed in any specimen, but this may have been due to the fact that the study period was relatively short.…”

Revision Transcervical Medialization Laryngoplasty for Unilateral Vocal Fold Paralysis

“…Revision ML is further complicated by scarring from previous dissection within the paraglottic space for implant placement. While limited fibrosis around a Gore-Tex implant has been shown 20 compared with silastic implants 21 in animal Subjective voice outcomes pre-and postrevision ML have previously been reported by 4 studies. 13,[16][17][18] Subjective voice improvement was noted in 80% of patients by Maragos 13 and Figure 2.…”

Use of polyethylene terephthalate and expanded-polytetrafluoroethylene in medialization laryngoplasty

“…He stressed that this surgical procedure should not be carried out in cases where there was a possibility that nerve function might return. 16 In another investigation, Whitmore compared PETP and e-PTFE as graft material in the sclera of rabbits. While e-PTFE could be easily removed from the capsule-like covering in the sclera, it was observed that PETP was rmly bound to the underlying tissue.…”