Canine heart-lung transplantation after 24-hour hypothermic preservation

We compared the efficacy of Belzer UW solution (UWS) with modified Collins solution (MCS) in a 24 h canine heterotopic heart-lung transplantation model. Nine pairs of mongrel dogs were divided into 2 groups: MCS group (n = 5) and UWS group (n = 4). The donor heart was arrested with cardioplegia. The heart and lung were flushed with MCS or UWS, excised en bloc and immersed in 4 degrees C MCS or UWS for 24 h. Graft function was adequate in 1 of 5 grafts in the MCS group and in all 4 grafts in the UWS group (P less than 0.05). In the UWS group, the prepreservation and posttransplantation cardiac output was 71.2 +/- 21.6 and 96.4 +/- 44.4 ml/min per kg, the PaO2 was 80.8 +/- 12.9 and 74.1 +/- 2.7 mmHg, and the PaCO2 was 25.6 +/- 5.5 and 35.9 +/- 13.3 mmHg, respectively. No difference was significant. In the UWS group, the pulmonary vascular resistance increased significantly to 13.8 +/- 3.7 from 8.8 +/- 5.2 Wood units (P less than 0.05). Post-transplantation myocardial water content in the UWS group (78.6 +/- 2.0) was less than in the MCS group (81.1 +/- 1.4, P less than 0.05). The wet/dry ratio of the lung increased significantly to 8.3 +/- 1.6 from 4.4 +/- 0.6 in the UWS group (P less than 0.01) and to 10.3 +/- 0.8 from 4.1 +/- 0.1 in the MCS group (P less than 0.01), but was less in the UWS group (P less than 0.05). These results suggest that UWS is more effective than MCS in 24 h heart-lung preservation, but does not prevent pulmonary oedema adequately.