Single lung transplantation for primary pulmonary hypertension

This is a report of our study of single lung transplantation in six patients with primary pulmonary hypertension. Patients included five females and one male, 27-54 years of age. Haemodynamic vasodilator studies with calcium channel blockers were ineffective in all six patients prior to transplantation. Our transplant criteria for adequate cardiac reserve were a right ventricular ejection fraction greater than 20% and a left ventricular ejection fraction greater than 40%. All patients underwent single lung transplantation with cardiopulmonary bypass. There was one early mortality. The cause of death was disseminated fungal sepsis. The mean pulmonary artery pressures of the six patients declined from 57.0 ± 12.6 mmHg to 24.7 ± 3.3 mmHg in the immediate postoperative period (p = 0.003 Mann-Whitney rank sum). Perfusion lung scanning performed four weeks after transplantation revealed 91.0 ± 3.4% of the perfusion to the allograft. Follow-up radionuclide angiography at six to 12 months showed the right ventricular ejection fraction in the five survivors increased from 27.4 ± 5.0% pre to 43.8 ± 2.9% postoperatively (p <0.001 paired Student's t-test). There were two late deaths from bronchiolitis obliterans at 15 and 20 months after transplantation. All survivors returned to New York Heart Association functional class I from their pre-operative level III or IV. We conclude that there is significant haemodynamic improvement immediately following single lung transplantation for primary pulmonary hypertension. Quality of life in the long-term survivors is good, although the occurrence of bronchiolitis obliterans is of concern.