Thrombus formation at the stump of the pulmonary vein after lobectomy: a prospective multi-institutional study

Purpose Recent reports suggest that postoperative cerebral infarction following lung cancer surgery is caused by thrombus formation at the stump of the pulmonary vein and that the risk is highest after left upper lobectomy (LUL). Thrombosis at the stump of the pulmonary vein and the incidence of cerebral infarction was investigated prospectively in patients who underwent lobectomy for lung cancer. Methods Lung cancer patients undergoing planned pulmonary lobectomy were enrolled. The endpoint was to confirm if there is a higher incidence of thrombus formation (primary) and a higher incidence of cerebral infarction (secondary) in patients undergoing LUL. We planned to accrue 600 patients. An interim analysis was scheduled for just after the data center received the final clinical review form of the 300th patient. Results The interim analysis revealed a significant difference in the primary endpoint. In the final analysis, thrombus was identified in 16 of 88 LUL patients (20.5%), and in 4 of 247 patients who underwent other types of lobectomy (1.6%) (p < 0.05). Cerebral infarction was identified in 1 of the LUL patients (1.3%) and in 9 of the other patients (3.6%) (p = 0.318). Conclusions Thrombus frequently forms at the stump of the left superior pulmonary vein after LUL. However, our study did not identify a relationship between thrombosis and cerebral infarction.