Extended cardiopulmonary preservation for heart-lung transplantation: a comparative study of superoxide dismutase.
We examined an 8-hour cardiopulmonary preservation technique and the role of free radical-induced injury during cardiopulmonary preservation and transplantation. Hence, donor dogs were placed on cardiopulmonary bypass, rapidly cooled to 15 degrees C, and heterotopic heart-unilateral left lung transplantations were performed. In group 1 (n = 5), hearts and lungs were transplanted immediately after core-cooling and cardioplegic arrest. In groups 2 to 5 (n = 5 in each group), heart-lung blocks were excised and stored at 4 degrees C for 8 hours before transplantation. During preservation hearts were perfused (20 mm Hg) with oxygenated extracellular solution (pH 7.4, 410 m0sm/L) and the lungs immersed in the same solution. In groups 3 through 5 recombinant human superoxide distumase (r,h-SOD, total 40 mg/kg) was administered during either donor cooling, donor preservation, or just before and during reperfusion, respectively. Load independent analysis of myocardial function was assessed by determining the ratio of the end-systolic pressure to end-systolic dimension. Pulmonary preservation was evaluated by determination of extravascular lung water of the implanted left lung, arterial oxygenation on 40% inspired oxygen, and pulmonary vascular resistance. Although arterial oxygenation was similar in each group, pulmonary vascular resistance was increased in groups 2 through 4 after implantation. Furthermore, in groups 2 and 4 impaired myocardial function and increased extravascular lung water were observed. Administration of r,h-SOD, however, just before and during reperfusion significantly enhanced cardiopulmonary preservation. These results indicate that free radical-induced injury is primarily the result of reperfusion. Thus the best time for administration of r,h-SOD is before and during reperfusion.(ABSTRACT TRUNCATED AT 250 WORDS)
Bando
K
K
Department of Surgery II, Okayama University Medical School, Japan.
Tago
M
M
Teraoka
H
H
Seno
S
S
Senoo
Y
Y
Teramoto
S
S
D000818:Animals; D003080:Cold Temperature; D004285:Dogs; D005110:Extracellular Space / Q000378:metabolism; D005609:Free Radicals; D006321:Heart / Q000503:physiopathology; D016027:Heart Transplantation; D016041:Heart-Lung Transplantation; D007101:Immersion; D008168:Lung / Q000098:blood supply / Q000378:metabolism; D016040:Lung Transplantation; D015428:Myocardial Reperfusion Injury / Q000209:etiology / Q000517:prevention & control; D009926:Organ Preservation / Q000379:methods; D010100:Oxygen / Q000009:adverse effects; D010477:Perfusion; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000627:therapeutic use; D015424:Reperfusion; D015427:Reperfusion Injury / Q000209:etiology / Q000517:prevention & control; D013482:Superoxide Dismutase / Q000008:administration & dosage / Q000627:therapeutic use*; D014655:Vascular Resistance
D005609:Free Radicals; D011994:Recombinant Proteins; D013482:Superoxide Dismutase; D010100:Oxygen