Pulmonary haemodynamics after single-lung transplantation for end-stage pulmonary parenchymal disease

Abstract

In a prospective study, we investigated the effect of single-lung transplantation (SLT) on pulmonary haemodynamics and the relationship between pulmonary hypertension (PH) and the fraction of perfusion to the transplant in patients with end-stage pulmonary parenchymal disease. Twenty four SLT recipients were included in the study, 19 with chronic obstructive pulmonary disease (COPD), two with sarcoidosis and three with fibrosing alveolitis. Spirometry, determination of arterial blood gas values, perfusion scintigraphy and right heart catheterization were performed before and 1, 6, 12 and 24 months after transplantation. Patients with a mean pulmonary artery pressure (P̄(pa)) ≤ 20 mmHg before transplantation were defined as having PH (PH group, 15 patients) and the remainder (9 patients) constituted the non-PH group. In the PH group, P̄(pa) and pulmonary vascular resistance (PVR) were significantly decreased after transplantation: 28 ± 2 to 18 ± 1 mmHg and 288 to 161 ± 11 dyne·s-1·cm-5, respectively (mean ± SEM). In the non-PH group, the haemodynamic parameters were unchanged after transplantation. Over the 2 year follow-up period, no significant change was found in P̄(pa) and PVR, nor any difference between the PH and non-PH group. There was no significant difference between the two groups in terms of pulmonary perfusion to the graft. In conclusion, patients with pulmonary hypertension obtain pulmonary haemodynamics within the normal range after single-lung transplantation. Presence or absence of pulmonary hypertension before transplantation does not influence perfusion to the graft. These findings persist up to 2 yrs, despite the coexistence of an 'end-stage' native lung and a lung transplant.