Cryobiopsy in the Diagnosis of Pulmonary Vein Stenosis After Catheter Ablation of Atrial Fibrillation: A Case Report.

Pulmonary vein stenosis-a complication of atrial fibrillation ablation unfamiliar to most pulmonologists-was identified in a 42-year-old man who presented with haemoptysis. Initial bronchoscopy at a previously visited hospital revealed a central airway lesion, but biopsy was declined because of its haemorrhagic nature. Repeat bronchoscopy at our hospital showed oedematous changes and vascular proliferation in the left main bronchus, suggesting adenoid cystic carcinoma. However, cryobiopsy excluded malignancy and suggested a vascular malformation with thickened, irregularly dilated muscular vessels. Contrast-enhanced CT revealed occlusion of the left superior pulmonary vein, interpreted as a secondary change. The patient had a history of catheter ablation for atrial fibrillation. Based on these findings, the stenosis was determined to be a complication of catheter ablation, and surgical bypass was performed. Severe pulmonary vein stenosis was successfully diagnosed using cryobiopsy. This condition is unfamiliar to pulmonologists; however, differentiation from airway tumours is crucial for determining treatment.