Polyglycolic acid/poly-L-lactic acid copolymer use in laryngotracheal reconstruction: a rabbit model

To evaluate the tissue response and resorption of the polyglycolic acid/poly-L-lactic acid (PGA/PLLA) implant in laryngotracheal reconstruction and compare its dynamic stability with autologous cartilage grafts.

An interventional, before-after trial.

Twenty-one white, female, New Zealand rabbits were divided into four groups. Groups A and B underwent laryngotracheoplasty using the PGA/PLLA implants of 3 and 4 mm widths. Group C received autologous ear cartilage grafts. Group D was the control group and did not undergo surgery. The subjects were sedated at 12 months, and the larynges were evaluated in vivo for stability and area measurements by way of endoscopy during spontaneous respiration. The subjects were then killed, the larynges harvested, and the negative intraluminal pressures applied to the laryngotracheal unit were measured in a closed-system apparatus. The larynges were then evaluated for inflammatory reaction and implant resorption by way of histologic analysis.

All implanted subjects survived without complications and grew normally. There was no appreciable subglottic collapse during spontaneous respiration under anesthesia. Ex vivo examination of maximum negative intraluminal pressures (-50 cm H2O) in a closed system demonstrated subglottic collapse of 78%, 72%, 61%, and 3% for groups A, B, C, and D, respectively, revealing the inherent weakness in the surgically manipulated airways regardless of grafting material. Histologically, the PGA/PLLA implants were essentially completely resorbed.

PGA/PLLA appears to be a safe and effective synthetic material for use in laryngotracheal reconstruction in the rabbit model while avoiding donor site morbidity and additional operative time. Reconstructed airways maintained adequate strength and patency under physiologic conditions and are comparable with autologous cartilage grafts.