Cerebral embolic stroke caused by a thrombus in the pulmonary vein stump after left pulmonary lobectomy is a serious complication. We retrospectively analyzed four patients who underwent mechanical thrombectomy for large-vessel occlusion after left pulmonary lobectomy between January 2014 and March 2022. Two cases occurred after left upper lobectomy and the others occurred after left lower lobectomy. All patients presented with cerebral embolic stroke from the day after surgery to the 9th postoperative day, and successful reperfusion was achieved in all cases. Two patients had good outcomes at 90 days. Thrombus in the pulmonary vein stump is the probable cause of cerebral embolism, and mechanical thrombectomy is effective. Further studies are required to establish preventive measures and perioperative management strategies.

After treatment of unilateral vertebral artery dissecting aneurysm (VADA), de novo VADA rarely occurs on the contralateral side. In this article, we report a case of subarachnoid hemorrhage (SAH) due to de novo VADA in the contralateral vertebral artery (VA) 3 years after parent artery occlusion of unilateral VADA, with a review of the literature. A 47-year-old woman was admitted to our hospital complaining of headache and impaired consciousness. Head computed tomography showed SAH, and three-dimensional computed tomography angiography showed a fusiform aneurysm in the left VA. We performed an emergency parent artery occlusion. Three years and 3 months after the initial treatment, the patient presented to our hospital with complaints of headache and neck pain. Magnetic resonance imaging revealed SAH, and magnetic resonance angiography revealed de novo VADA in the right VA. We performed a stent-assisted coil embolization. The patient had a good postoperative course and was discharged with a modified Rankin scale score of 0. Long-term follow-up is necessary in patients with VADA because contralateral de novo VADA can develop even several years after the initial treatment.