P2.16-023 Changes of the Pulmonary Artery After Resection of Stage I Lung Cancer

Abstract

Radiologists focus on the anatomic changes in the lung itself when interpreting postoperative surveillance CT scans, but the anatomic and physiologic effects of lung resection on the other organs of the thorax, specifically the pulmonary artery (PA), have not been well studied. Potential variations in PA size over time have been recognized as predictors of post-surgical complications and the development of pulmonary hypertension. The International Early Lung Cancer Action Program (I-ELCAP) database was queried for lung cancer patients who underwent lobectomy and had both preoperative and postoperative CT imaging. Case-specific details were previously recorded in the database as per I-ELCAP protocol. All surgeries were performed by general thoracic surgeons. All CT imaging for each patient was reviewed by a fellowship-trained chest radiologist. Among the 142 subjects who underwent lobectomy, the median follow-up time from the pre-surgical CT to the last reviewable CT was 53.2 months (IQR: 27.9-100.4 months). The average increase in the size of the main pulmonary artery (mPA) was 1.5 mm (19.9 mm to 21.4 mm, P < 0.0001). There was also a significant increase between the pre-surgical CT and the initial postoperative CT which was on average 12.6 months later from 19.9 mm to 20.7 mm (P = 0.0002). Considering patients with and without CT evidence of emphysema, the 82 with emphysema had a smaller average change of the main PA between the pre-surgical and the last reviewable CT than the 60 without emphysema (1.0 mm vs. 1.8 mm, P = 0.08). Patients undergoing lobectomy appear to be at increased risk for enlargement of their pulmonary artery diameters after surgery. These results show that a focus on all the organs in the thorax, not just the lungs themselves, is important when evaluating postoperative lung resection CTs.