2003, VOL. 11, NO. 3 237 ASIAN CARDIOVASCULAR & THORACIC ANNALS Saueressig Glycerin-Preserved Tracheal Implant ORIGINAL CONTRIBUTION Rejection and Indirect Revascularization of Glycerin-Preserved Tracheal Implant Maurício G Saueressig, MSc, Alexandre H Moreschi, MSc, Gilberto V Barbosa, MD, Maria IA Edelweiss, PhD, Felipe H de Souza, JD, Fabrício L Saveg nag o, JD, Amarílio V de M acedo Neto, PhD Department of Thoracic Surgery and Lung Transplantation Hospital de Clínicas de Porto Alegre Federal University of Rio Grande do Sul Porto Alegre - Brazil For reprint information contact: Maurício G Saueressig, MSc Tel: 55-51-3321-2101 Fax: 55-51-3316-8684 email: mguidi@zaz.com.br 2171, Ramiro Barcelos St., Ap.21, 90035-007, Porto Alegre - Brazil. INTRODUCTION Tracheoplasty is the most common surgical treatment of benign and malignant tracheal diseases. However, there is still no definitive solution for the problem of reconstruction of defects larger than 60% of the trachea. 1 The best anatomical and physiological replacement of the trachea is its own allograft 2 since the use of prostheses and autografts to replace the trachea has shown contradictory results that are difficult to reproduce. 1 The routine use of tracheal transplants depends on the solution of three problems: revascularization, rejection and preservation of grafts. 2 Tracheal graft ischemia is the main cause of transplant failure. Therefore, the graft has ABSTRACT The objective of the following study was to evaluate antigenicity, malacia and revascularization in glycerin-preserved canine tracheal allografts. Trachea with six cartilage rings (2.4 to 3.1 cm) were distributed in three study groups: autograft (21), allograft (18) and glycerin-preserved (22). We implanted two segments from different groups in the greater omentum of dogs. After 28 days, latex was injected in the canine aorta before the segments were harvested. We evaluated number of sectors with functional vessels, number of vessels dyed in the submucosa, acute arteritis score, incidence of acute rejection, cartilage lesion score, and malacia. The autograft group had a larger number of dyed vessels than the glycerin-preserved group. The autograft group also had a higher average number of quadrants with functional vessels than the allograft group and the glycerin-preserved group. The allograft group had a higher mean score for acute arteritis than the autograft group and more acute rejection than the glycerin-preserved group. The cartilage lesion score did not show any significant difference between groups. Malacia was not observed in any tracheal segment. Overall, the glycerin-preserved tracheal implant had low antigenicity and good rigidity, but showed incomplete revascularization. (Asian Cardiovasc Thorac Ann 2003;11:237–44) to be revascularized with flaps of the greater omentum, lateral thoracic fascia, muscle, or direct vascular anastomosis with en bloc cervicothoracic exenteration. 1-3 Arteritis characterizes acute vascular rejection of the trachea and results in thrombosis of microcirculation in the submucosa and, consequently, in ischemic necrosis of the respiratory epithelium, of the interstitium and, finally, of the cartilage. 4 The denudation of respiratory epithelium, where Major Histocompatibility Complex (MHC) class II is found, as well as the degeneration of chondrocytes in the tracheal allograft, are effects of the method of preservation, which reduces tracheal antigenicity. 11 Therefore, besides reducing