Single lung transplantation in piglets. Technique and follow-up.

Single lung transplantation was performed in 21 piglets in order to develop a new experimental model for study of chronic rejection phenomena. In group I (unmodified rejection), acute rejection occurred in recipients which survived transplant and mean survival was 7 days. In Group II (triple immunodepression) the mean follow-up was 32 (0-134) days. Acute rejection was histologically detected in five of the 13 allografts and moderate to strong chronic vascular rejection in four. In group III (untreated autografts) the postoperative course was uneventful. The 60-day weight gain was 113% in group II, and 167% in group III. Computed tomography in group II showed 95% increase in allograft volume and 145% increase in contralateral lung volume (mean follow-up 102 days, n = 3). The corresponding gains in bronchial diameter were 39% and 40%. The piglet model allowed versatile monitoring of lung transplants, with manifestations of acute and chronic rejection providing valuable material for further studies. The significant recipient and allograft growth indicate that also children may be accepted as candidates for lung transplantation.