Effect of lung volume reduction surgery on pulmonary hemodynamics in severe pulmonary emphysema

The presence of pulmonary hypertension in severe pulmonary emphysema has been considered a relative contraindication to lung volume reduction surgery (LVRS). There was concern that resection of lung tissue might further increase pulmonary artery pressure. To address this point, the prevalence of pulmonary hypertension in candidates for LVRS was investigated. The changes in pulmonary artery pressures after bilateral videoassisted thoracoscopic resection was studied in patients with homo- and heterogeneously destroyed emphysematous lungs.

The pulmonary arterial pressures by right heart catheterization were prospectively assessed, before and 6 months after LVRS in 21 consecutive patients (15 males, six females, mean (+/- S.E.) age: 62 +/- 1.9, range 42-74 years). All were former smokers and three had ZZ-AT1 deficiency. The inclusion criteria were: (a) severe bronchial obstruction (FEV1 < 35% predicted); (b) pulmonary hyperinflation (RV/TLC > 0.60); and (c) absence of hypercapnia (PaCO2 < 50 mmHg).

The FEV1 had increased from 28 +/- 2% to 35 +/- 3% of the predicted value (P < 0.05) 6 months after surgery. The RV/TLC had declined from 0.65 +/- 0.02 to 0.55 +/- 0.02; PaO2 increased (66 +/- 1 versus 71 +/- 2 mmHg, P = 0.04), PaCO2 (38 +/- 2 versus 36 +/- 1 mmHg, P = 0.26) did not change. The pulmonary artery mean pressure (PAPmean) remained unchanged (18 +/- 1 versus 19 +/- 1 mmHg, P = 0.26). In six patients PAPmean was > or = 20 mmHg (up to 24 mmHg) preoperatively. After 6 months, six patients had a PAPmean > or = 20 mmHg (up to 31 mmHg).

In patients with severe emphysema who are candidates for LVRS (but have only mild to moderate hypoxemia and a PaCO2 < 50 mmHg) we found no relevant pulmonary hypertension and pulmonary artery pressure did not change significantly after surgery. Therefore, routine right heart catheterization is not mandatory for preoperative evaluation.