The hemodynamic performance of standard bileaflet valves is impaired by a tilted implantation position

Abstract

Tilting of bileaflet valves resulted in a significant impairment of systolic and diastolic hemodynamics. Superiority of larger valves diminished in the tilted position. The strongest tilting effect was seen at 90 degrees rotation. Such a position should therefore be avoided or surgically corrected by rotating the valve.

Defining the Efficacy of Aortic Root Enlargement Procedures: A Comparative Analysis of Surgical Techniques

“…While it may be possible to implant a valve 1 size larger using a combination of the Nicks enlargement and oblique implantation of the prosthesis, 18 recent studies have revealed that the hemodynamic advantages of implanting a larger mechanical valve prosthesis is diminished when the prosthesis is implanted in a moderately tilted position. 23 As such, we choose to implant a larger prosthesis only if it can be inserted with minimal tilting. Furthermore, though this technique may be used to pass a larger prosthesis through a small sinotubular junction, the implantable prosthesis size should be determined by the annular diameter, and not the sinotubular junction.…”

Mechanical Concepts Applied in Congenital Heart Disease and Cardiac Surgery

“…Any obstruction to flow is associated with energy loss. In the context of valve replacement, angling the valve ring relative to the flow jet is a cause for energy loss [13,25], as might occur during pulmonary valve implantation in indistinct pulmonary annulus, years after repair of tetralogy of Fallot with a transannular patch. Energy loss in these patients correlates with the indexed end-diastolic diameter and the efficiency of RV contraction [26], which determines the timing of surgery.…”

Characteristics of Pulsatile Blood Flow Through the Curved Bileaflet Mechanical Heart Valve Installed in Two Different Types of Blood Vessels: Velocity and Pressure of Blood Flow

“…With bioprostheses, there is no need for lifetime anticoagulation; however, these valves deteriorate as they become calcified and stenotic, so that half of the patients need redo surgery within 10 to 15 years. 2 Mechanical valves, in contrast, require permanent anticoagulation, with its associated risk of bleeding and thromboembolic events. 2 Bileaflet mechanical heart valve substitutes have gained increasing acceptance because of good in vitro and clinical performances.…”

“…2 Mechanical valves, in contrast, require permanent anticoagulation, with its associated risk of bleeding and thromboembolic events. 2 Bileaflet mechanical heart valve substitutes have gained increasing acceptance because of good in vitro and clinical performances. 3 Structural failure of bileaflet mechanical heart valves (MHV) implanted in patients has been reported in the literature.…”