Cardiac pathology after aortic valve replacement using Hufnagel trileaflet prostheses: a study of 20 necropsy patients.

Necropsy observations are described in 20 patients dying between October 1967 and March 1973 after replacement of the aortic valve with a Hufnagel trileaflet prosthesis. Seven patients died within two months of operation and 13, between 2.1 and 58 months (average 22). Four of seven patients dying early had extensive prosthetic thrombus causing obstruction of one coronary arterial ostium in each. Of the 12 patients surviving six months or longer after valve replacement, death in eight resulted from degeneration (tearing) of the prosthetic cusps causing severe aortic regurgitation in each, and from thrombosis of the prostheses in three, probably causing prosthetic stenosis and defintely causing narrowing of at least one coronary ostium. Thus, prosthetic degeneration or thrombosis caused death in 11 of the 12 patients surviving six months or longer. In conclusion, this trileaflet aortic prosthesis, although similar in design to the normal aortic valve, is composed of materials not durable enough to withstand the stresses created by blood flow in this position.