Cerebral Embolism Caused by Pulmonary Vein Stump Compression Due to Postoperative Exacerbation of Hiatal Hernia After Left Lower Lobectomy: A Case Report.

Cerebral infarction after lung cancer surgery is a critical complication typically associated with thrombus formation in the long pulmonary vein stump, particularly after left upper lobectomy (LUL). Conversely, the risk of thrombus formation after left lower lobectomy (LLL) is low because of the anatomically shorter stump. A man in his 70s underwent video-assisted thoracoscopic surgery (VATS) left lower lobectomy for lung cancer. On postoperative day 1, the patient developed sudden right hemiplegia, global aphasia, and left conjugate deviation. Magnetic resonance imaging (MRI) revealed an acute cerebral infarction due to left middle cerebral artery (M1) occlusion. As intravenous thrombolysis was contraindicated in the immediate postoperative period, emergent mechanical thrombectomy using a direct aspiration first-pass technique (ADAPT) was performed to achieve complete recanalization (TICI 3). ADAPT thrombectomy is a safe and effective preferred strategy for acute macrovascular occlusion that cannot be intravenously thrombolysis in the early postoperative period. Postoperative investigation revealed an acute exacerbation of the hiatal hernia, which physically compressed and obstructed the stump of the left inferior pulmonary vein. The retrieved thrombus was a mixed thrombus composed of erythrocytes and fibrin, consistent with the formation due to stasis in an obstructed space. LLL is an independent risk factor for postoperative hiatal hernia exacerbation. This case suggests that even an anatomically "short stump" can develop severe hemodynamic stasis leading to thrombosis if subjected to external mechanical compression. Clinicians must recognize that even after LLL, anatomical changes, such as hiatal hernia exacerbation, can introduce a risk of pulmonary vein thrombosis and subsequent cerebral embolism.