Simulated reflux and laryngotracheal reconstruction: a rabbit model.
OBJECTIVE
(1) To test the feasibility of a rabbit model using a pharyngostomy tube to simulate gastroesophageal reflux and (2) to study the effects of gastroesophageal reflux on laryngotracheal reconstruction using a new rabbit model.


METHODS
Prospective randomized trial.


METHODS
Thirty-three New Zealand white rabbits.


METHODS
Anterior cartilage laryngotracheoplasty and pharyngostomy tube placement into the pyriform sinus were performed in 33 rabbits, 22 of which are included in this analysis. Beginning postoperative day 1, hydrochloric acid at a pH of 1.5 with pepsin (n = 7) or at a pH of 4.0 with pepsin (n = 8) was irrigated twice daily through the pharyngostomy tube to simulate gastroesophageal reflux, and a control group received twice-daily isotonic sodium chloride solution irrigations (n = 7).


METHODS
Specimens were scored by a pathologist masked to individual groups using a newly modified inflammation scoring system. In addition, cross-sectional areas of the cartilage grafts and subglottic airway lumina were compared.


RESULTS
Inflammation scores were significantly higher in rabbits receiving hydrochloric acid and pepsin irrigations at a pH of 4.0 (P =.04) but not in those in the pH 1.5 group. Cartilage necrosis was prominent in all groups, and airway sizes and cross-sectional areas of the grafts were not significantly different among the 3 groups.


CONCLUSIONS
Cartilage necrosis is prominent during the early stages after laryngotracheoplasty. Inflammation can be increased using hydrochloric acid and pepsin irrigations but is difficult to predict based on this study. Although we confirmed the feasibility of this model, further modifications of this study are proposed to improve animal survival and data collection.
Carron
J D
JD
Department of Otolaryngology-Head and Neck Surgery, Eastern Virginia Medical School, Norfolk, VA 23507, USA. jdcarron@yahoo.com
Greinwald
J H
JH
Oberman
J P
JP
Werner
A L
AL
Derkay
C S
CS
D000818:Animals; D002356:Cartilage / Q000473:pathology / Q000637:transplantation; D004195:Disease Models, Animal; D005240:Feasibility Studies; D005764:Gastroesophageal Reflux / Q000503:physiopathology*; D006851:Hydrochloric Acid / Q000494:pharmacology; D007440:Intubation; D007830:Larynx / Q000601:surgery*; D008297:Male; D009336:Necrosis; D010434:Pepsin A / Q000494:pharmacology; D011184:Postoperative Period; D011446:Prospective Studies; D011817:Rabbits; D011897:Random Allocation; D019651:Plastic Surgery Procedures; D014132:Trachea / Q000601:surgery*
D010434:Pepsin A; D006851:Hydrochloric Acid