Thrombosis in the pulmonary vein stump after left upper lobectomy as a possible cause of cerebral infarction

Background: Thrombus in the stump of the pulmonary vein (PV) is not a well-known complication after lung resection, and it has the potential to cause embolism to vital organs. To clarify the frequency, risk factors, and cause of this complication, a retrospective clinical study of patients who underwent lobectomy was performed. Methods: The study evaluated 193 patients with primary lung cancer who underwent lobectomy from 2005 to 2011 and contrast-enhanced chest computed tomography (CT) within 2 years after lobectomy. Contrast-enhanced CT was retrospectively interpreted to check for thrombus in the PV stump. Results: The operative procedures were 65 right upper lobectomies, 14 right middle lobectomies, 40 right lower lobectomies, 52 left upper lobectomies (LUL), and 22 left lower lobectomies. Thrombus developed in the PV stump in 7 of the 193 patients (3.6%) after lobectomy. All patients with thrombus had undergone LUL, and 13.5% of those who had undergone LUL developed thrombus. Univariate analyses revealed that LUL and operation time were significant risk factors and that adjuvant chemotherapy was marginally significant. It appears that thrombus may be attributable to the length of the PV stump. Measurement of the length of the PV stump using 3-dimensional CT images of the PV revealed that the stump of the left superior PV was longer than the others. Conclusions: Thrombus in the PV stump occurred in 13.5% of patients after LUL. These findings suggest that contrast-enhanced CT should be recommended for patients after LUL to help identify those with a high risk for thromboembolism.