Left Lower Lobectomy for Lung Cancer Complicated by Unilateral Absence of the Left Pulmonary Artery: A Case Report

Unilateral absence of the pulmonary artery (UAPA) is a rare congenital vascular anomaly, often diagnosed in childhood but sometimes remaining asymptomatic until adulthood. Its coexistence with primary lung cancer is exceptionally uncommon. Surgical resection in such cases poses risks due to absence of the pulmonary artery and hypertrophied systemic vessels, which may lead to bleeding or ischemic complications.

A 69-year-old woman with a history of unilateral interstitial pneumonia was referred for evaluation of a growing nodule in the left lower lobe. She was asymptomatic, with no prior hemoptysis or infection. Imaging revealed left-sided UAPA with systemic collateral perfusion. Two 18F-fluorodeoxyglucose (FDG)-avid pulmonary nodules were detected, raising suspicion for stage IA3 (S9) and IA2 (S8) lung cancer. To avoid the high morbidity associated with pneumonectomy while achieving oncologic control, a left lower lobectomy was performed. Intraoperative findings included hypertrophied systemic vessels and absence of the pulmonary artery, which required conversion to thoracotomy due to bleeding from collateral vessels forming the fused fissure and anatomical complexity. The bronchial stump was reinforced with a free fat pad. Although the initial postoperative course was uneventful, bronchoscopy on POD 90 revealed a bronchopleural fistula. The patient was managed conservatively with close observation, during which bronchial epithelial perfusion gradually recovered, and she has remained clinically stable without additional intervention.

Management of asymptomatic adult UAPA complicated by ipsilateral lung cancer requires careful, case-specific surgical planning. Lobectomy was selected to reduce pneumonectomy-related risks. Implementing preventive measures-such as a pedicled muscle flap or pericardial fat pad for bronchial stump coverage-is advisable to reduce ischemic risk in such cases.