J. Aagaard et al., Expanding the use of total mitral valve preservation in combination with implantation of the CarboMedics heart valve prosthesis, J CARD SURG, 40(2), 1999, pp. 177-181
Background, Preservation of the mitral valve and subvalvular apparatus was
introduced into the clinic in the early sixties, but for two decades the st
andard technique for mitral valve replacement included excision of both lea
flets and their attached chordae tendineae. Lately, increased emphasis has
again been placed on retention of the mitral subvalvular apparatus during v
alve replacement because of its role on left ventricular function.
Methods. We have preserved the valvular and subvalvular mitral apparatus, w
hen possible, in connection with mitral valve replacement during the last s
even years and the present investigation (partly prospective and partly ret
rospective) was done with the aim of making up the results of our mitral pr
eservation technique. In the period between January 1990 and December 1995,
30% of the patients who underwent mitral valve replacement had complete re
tention of all mitral tissue. In 1996, the percentage had increased to 50,
and during the first seven months of 1997, 70% of the patients had complete
retention of all mitral tissue. Since January 1997, we have exclusively us
ed the CarboMedics mitral heart valve prosthesis. A total of 56 patients we
re identified to have had a CarboMedics heart valve prosthesis implanted. T
here were 33 men and 23 women with a mean age of 63 years, range 23-77 year
s. Coronary bypass was a concomitant procedure in 22 patients. In seven pat
ients, both the mitral and aortic valves were replaced. A severely altered
valve with thickened and or calcified leaflets, stenotic leaflets, or short
ened, retracted and thickened chordae tendineae were not a contraindication
for the procedure. Calcified plaques were removed. Adhesion between anteri
or and posterior leaflets was treated with sharp dissection. Valve and subv
alvular tissue were preserved. The leaflets were reefed within the valve-su
tures and compressed between the sewing ring acid the native annulus when i
mplanting the valve prosthesis. Chordal tension on the ventricle was thereb
y maintained and the chordae pulled away from the valve effluent. Echocardi
ography with measurement of ejection-fraction was performed preoperatively
during the postoperative course in case of cardiac problems and on a routin
e basis 1 month after surgery and at various intervals when the patient was
seen in the outpatient clinic. Left ventricular outflow tract gradients we
re measured during the postoperative course in case of cardiac problems and
routinely 1 month postsurgically.
Results. Five patients died in the postoperative period and one patient had
transient neurological symptoms. In none of the patients was death or tran
sient neurological symptoms a consequence of the retention of mitral leafle
ts with subvalvular apparatus. The remaining 51 patients were all alive at
follow-up. Postoperative echocardiography demonstrated a preserved;left ven
tricular function and a left ventricular outflow tract without obstruction.
Conclusions. We find that the described technique in combination with impla
ntation of a CarboMedics heart valve prosthesis is very useful even in pati
ents with a severely altered valve, when preserving the mitral leaflets wit
h subvalvular apparatus during valve replacement. The technique is without
procedure related complications and preserves left ventricular function wit
hout obstructing the left ventricular outflow tract.