Pulmonary metastasectomy with lung-sparing local excisions is a widely accepted method of treating stage IV malignancies in selected cases. The ability to predict postoperative lung function is an unresolved issue, especially when multiple wedge resections are planned. To help develop a method to predict postoperative lung function after wedge resections, we present this prospective observational study.
A total of 77 patients who underwent one or more wedge resections to remove lung metastases completed the study protocol. Spirometry results, diffusion capacity of lung for carbon monoxide (Dlco), and blood gases and potential confounding factors were measured prior to, immediately following, and 3 months after the procedure and were analyzed.
Seventy-seven patients with a median age of 61.3 years underwent up to 22 wedge resections. The mean lung function losses were FVC (−7.5%), total lung capacity (TLC) (−7.9%), FEV1 (−9.2%), and Dlco (−8.8%), and all were statistically significant (P < .001). The lung function losses also differed significantly between those having a single and those with more than eight wedge resections. Using regression analysis, we found that for every additional wedge resection, there was a reduction in FVC of 30 mL (0.7%), in TLC of 44 mL (0.65%), and in FEV1 of 23 mL (0.58%).
Metastasectomy by wedge resection significantly reduces lung function parameters. As a benchmark, we can predict a 0.6% decrease in spirometry values and Dlco for every additional wedge resection, and a decrease of approximately 5% that may be attributed to thoracotomy.