Predictors of postoperative outcome after pulmonary endarterectomy from a 14-year experience with 279 patients

Abstract

Objective: Postoperative outcome after pulmonary endarterectomy (PEA) for chronic thromboembolic pulmonary hypertension (CTEPH) is difficult to predict. We sought to analyze specific preoperative findings to predict mortality, shorter mechanical ventilation, and hemodynamic improvement after PEA.

Methods: A total of 279 patients with CTEPH (57 ± 14 years old, 57% male), who underwent PEA between 1995 and 2009, were reviewed retrospectively. Preoperative pulmonary hemodynamic parameters, spirometry data, laboratory data, cardiac co-morbidities, clinical stage, and number of desobliterated segments were analyzed using a logistic regression model to identify independent predictors for early mortality, shorter duration of mechanical ventilation, and hemodynamic improvement.

Results: There were 31 early deaths (11.1%, last three years: 6.7%). Among 16 significant predictors for early mortality, preoperative arterial oxygenation was the only significant predictor in multivariate analysis (P < 0.05). A total of 147 patients (52.7%) could be extubated within 48 h postoperatively. Out of 16 significant predictors in univariate analysis for mechanical ventilation less than 48 h, only higher forced expiratory volume in 1s FEV1.0 (P < 0.05) and higher preoperative cardiac index (P < 0.05) were significant in multivariate analysis. In 185 patients (66.3%), postoperative pulmonary vascular resistance (PVR) was reduced to lower than 400 dyn s(-1) cm(-5) at 48 h after PEA. Male gender (P < 0.05), lower preoperative mean pulmonary arterial pressure (PAP) (P < 0.05), and more intra-operative desobliterated segments (P < 0.01) were identified as significant predictors for this hemodynamic response with sensitivity of 77.5% and specificity of 67.9%. Using Pearson's correlation coefficient, PVR at 48 h after PEA could be estimated as PVR = 123.266+135.471 × creatinine-22.053 × desobliterated segments + 3.248 × systolic PAP (P < 0.01, R(2) = 0.401, 95% confidence interval = 0.464-0.830).

Conclusions: Preoperative factors can primarily predict postoperative outcome after PEA. Patients with underlying parenchymal lung disease will have increased risk for early mortality and prolonged mechanical ventilation. The extent of desobliterated segments as well as preoperative hemodynamic severity play a key role in predicting good hemodynamic responders.