Radiologic Findings and Endovascular Management of a Rasmussen Aneurysm

Purpose: Rasmussen pseudoaneurysm (RPA) refers to an aneurysm of the small to medium pulmonary artery branches that develops adjacent to a tuberculous cavity. RPAs arise in 5% of patients with pulmonary tuberculosis (TB) because of arterial wall thinning from granular scar tissue formation. The adventitia and media of the pulmonary arterial wall is replaced with granulation tissue, causing the formation of a pseudoaneurysm.

Materials and Methods: We present the case of a 75-year-old woman with a past medical history of atrial fibrillation, chronic obstructive pulmonary disease, positive purified protein derivative result, asthma, and hypertension who presented with mild hemoptysis. Computed tomography (CT) revealed bilateral pulmonary infiltrates with a right upper lobe cavitation. Three consecutive negative acid-fast bacillus smears were obtained. CT angiography revealed a vascular structure emanating from the segmental branch of the right upper lobe pulmonary artery, measuring 2.1 × 1.8 cm.

Results: Pulmonary angiography demonstrated a large pseudoaneurysm originating from the posterior division of the right upper lobar pulmonary artery. Intervention from the right groin through the common femoral vein allowed access to the right pulmonary artery, where five endovascular coils were deposited to embolize the pseudoaneurysm. The pseudoaneurysm was successfully thrombosed with the intraarterial injection of 2 mL of a 5000 units/mL thrombin solution. This was followed by coil deployment within the feeding artery. The final pulmonary angiogram disclosed no evidence of blood flow across the posterior division. The pseudoaneurysm was no longer visualized. The patient was hemodynamically stable and remained in the cardiovascular intensive care unit for 7 days after coil embolization. Her hemoglobin stabilized after the procedure, and she was discharged thereafter. Primary risks associated with this procedure are accidental perforation of the pseudoaneurysm from the catheter or complete infarction of the right lung if the coils are mistakenly placed in the main Pulmonary Artery (PA) instead of the pseudoaneurysm. This case report demonstrates proper recognition and treatment of RPAs.

Conclusions: Because of their rare prevalence, Rasmussen aneurysms are often overlooked. A retrospective study revealed that 38% of patients with TB with rebleeds subsequent to successful bronchial artery embolization for hemoptysis had RPAs. CT angiography is the best radiologic diagnostic method to identify RPAs, enabling prompt appropriate embolization.