A prospective randomized trial of complete atrioventricular transplantation versus ventricular transplantation with atrioplasty.

BACKGROUND: The standard technique of ventricular transplantation with atrioplasty (SOHT) distorts atrial anatomy. This may compromise diastolic ventricular function, impair atrioventricular valve competence and elevate resting ANP secretion. In contrast, complete atrioventricular anastomosis (CAVT) preserves atrial geometry. METHODS: We evaluated long term outcome in a prospective randomized trial of CAVT vs. SOHT. The primary outcome measures were peak oxygen uptake, atrioventricular valve regurgitation and ANP secretion. RESULTS: 58 recipients (median age 49 years; range 21-64) were consecutively randomized (29 CAVT; 29 SOHT). There were no differences in total ischaemic time, cardiopulmonary bypass time, postoperative bleeding or immunosuppression. Cardiopulmonary exercise tolerance testing was performed by 29 recipients at 742 to 1825 days. Pulmonary function was equivalent. Peak oxygen consumption expressed as a percentage of predicted maximum was 53.5% with CAVT and 63.8% with SOHT (p = 0.14). Echocardiography was performed on 41 recipients at 944 to 1665 days. There was less tricuspid regurgitation with CAVT (3/22 [13.6%] CAVT vs. 10/19 [52.6%] SOHT; p = 0.019). The incidence of mitral regurgitation was similar (5/22 [22.7%] CAVT vs. 4/19 [21.1%] SOHT; p = 0.803). Resting ANP secretion was assessed in 17 recipients at 1013 to 1812 days. All were hemodynamically stable and none had concurrent rejection. Resting ANP secretion was less with CAVT (CAVT: 283 pg/ml; SOHT: 521.4; p = 0.041). CONCLUSIONS: Peak oxygen consumption was not influenced by implantation technique. However, CAVT reduced the incidence of tricuspid regurgitation and attenuated the elevation in resting ANP secretion.

The effect of recipient lung size on lung physiology after heart-lung transplantation.

We studied the postoperative course of lung volumes in 32 heart-lung transplant recipients relative to the predicted total lung capacity of the individual donors, to assess the degree of inaccuracy likely to result from the radiological method of matching of donor and recipient lung sizes. There was a tendency for recipients with large preoperative lung volumes--from, for example, emphysema--to receive smaller lungs, while those with smaller volumes from pulmonary vascular disease received bigger donor lungs, but no immediate problems were incurred. After an initial fall in total lung capacity, the postoperative value of the total lung capacity approached the recipients' pretransplant value about one year after the operation irrespective of the size of the donor lungs. This suggests that chest wall compliance is the major determinant of postoperative lung volume and not the donor lung size or compliance. Exact matching of donors' and recipients' lung sizes may not be necessary, and if required can be simply achieved by comparing the measured total lung capacity in the recipient with the predicted value of the donor based on sex, age, and height.