Impact of preoperative pulmonary function on outcomes after open repair of descending and thoracoabdominal aortic aneurysms

Objective To evaluate the impact of preoperative pulmonary function on outcomes after open repair of descending thoracic (DTA) and thoracoabdominal aortic (TAAA) aneurysms. Methods The outcomes of patients undergoing open repair of DTA or TAAA were analyzed in relation to the results of preoperative pulmonary function tests. Receiver operating characteristic was adopted to assess the effect of forced expiratory volume in one second (FEV1) on the incidence of mortality. Logistic regression analysis and propensity score matching were used. Results Between 1997 and 2015, 726 patients underwent open DTA or TAAA repair. Pulmonary function tests were available in 711 (97.9%). Receiver operating characteristic analysis revealed the cutoff value of FEV1 to be 50%. Propensity score matching led to 149 pairs of patients with FEV1 below and above 50% with only limited residual imbalance. In the matched population operative mortality was 11.4% and 6.0% in patients with FEV1 ≤ 50% and FEV1 ≥ 51%, respectively (P = .10). The incidence of major adverse events was 33.1% in cases with FEV1 ≤ 50% and 19.5% in those with FEV1 ≥ 51% (P = .008). FEV1 ≤ 50% was associated with a 6.99× increase in the risk of major postoperative adverse events at logistic regression analysis. Conclusions Preoperative FEV1 < 50% is strongly predictive of increased respiratory failure, tracheostomy, and operative mortality in patients undergoing open DTA/TAAA repair. For these very high-risk patients with either extensive TAAAs or anatomy unsuitable for endovascular repair, medical therapy may offer the best long-term survival.