Delayed mechanical mitral prosthetic leaflet detachment with distal embolization and conservative management: a case report

Mechanical prosthetic valve leaflet detachment is an exceedingly rare but potentially fatal complication of valve replacement surgery, typically presenting with acute severe regurgitation and hemodynamic collapse. The underlying mechanisms remain incompletely understood, and management of embolized leaflet fragments represents a unique therapeutic challenge. To our knowledge, this represents a previously unreported clinical observation of leaflet escape involving a Sorin Bicarbon Fitline prosthesis; however, whether this event represents a prosthesis-specific failure mechanism remains uncertain. A 54-year-old man presented with acute decompensated heart failure 15 years after mechanical mitral valve replacement with a 29-mm Sorin Bicarbon Fitline prosthesis. His condition deteriorated rapidly, requiring transfer to the intensive care unit. Transthoracic echocardiography revealed severe prosthetic regurgitation but failed to define the mechanism of prosthetic dysfunction because of acoustic shadowing. Urgent transesophageal echocardiography confirmed single-leaflet detachment, while computed tomography localized the embolized leaflet fragment to the aortoiliac bifurcation. Emergency redo sternotomy with repeat mitral valve replacement and concomitant aortic valve replacement was successfully performed. Endovascular retrieval of the embolized leaflet was considered technically infeasible because no dedicated retrieval device was available for a rigid prosthetic leaflet with this size and geometry. Given its stable non-occlusive location, limited immediate risk, and the substantial surgical trauma associated with open retrieval, conservative management was selected. Contrast-enhanced computed tomography performed one month later identified two discrete embolized fragments: a larger fragment in the distal abdominal aorta and a smaller fragment in the distal right common iliac artery proximal to its bifurcation. Follow-up imaging at three months demonstrated stable positions of both fragments without evidence of migration. This case highlights the diagnostic complexity and therapeutic challenges associated with late mechanical valve leaflet detachment with distal embolization. Although leaflet escape involving the Sorin Bicarbon Fitline prosthesis has not been previously reported, this observation does not establish a prosthesis-specific failure mechanism. Conservative management of stable, non-occlusive embolized fragments may be considered in carefully selected patients when retrieval carries disproportionate procedural risks, provided that structured imaging surveillance and predefined criteria for intervention are established.