Limitations of multimodality imaging in the diagnosis of pannus formation in prosthetic aortic valve and review of the literature

Abstract

Pannus formation is a rare complication and occurs almost exclusively in mechanical prosthetic valves. It consists of fibrous tissue that covers the surface of the prosthesis either concentrically or eccentrically, resulting in valve dysfunction. The pathophysiology seems to be associated to a chronic inflammatory process that explains the late and insidious clinical presentation. This diagnosis should be considered in patients with high transvalvular gradients on transthoracic echo, and workup should be completed with fluoroscopy and transesophageal echocardiography. Treatment is always surgical and recurrence is rare. We present a case of pannus formation in a prosthetic aortic valve and a review of the literature regarding this disorder.

Keywords: Pannus formation, Prosthetic aortic valve, Fluoroscopy, Transthoracic echocardiography, Transesophageal echocardiography

Core tip: Pannus is an infrequent complication that mainly affects mechanical prosthetic valves. Its diagnosis requires clinical suspicion and the association of fluoroscopy, transthoracic and transesophageal echocardiography. The case presented is a characteristic example of pannus, given its clinical presentation (progressive dyspnea), the steps followed to reach diagnosis and the surgical resolution. Suspecting this disorder and making an accurate diagnosis is of paramount importance, to implement adequate treatment and to avoid prolonging the natural course of the disease and its repercussion on the left ventricle and the quality of life of affected patients.