The Journal of Thoracic and Cardiovascular Surgery, Vol 88, 248-252, Copyright © 1984 by The American Association for Thoracic Surgery and The Western Thoracic Surgical Association
Evaluation of suture techniques for mitral valve replacement
JR Newton Jr, DD Glower, JW Davis and JS Rankin
Although periprosthetic leak is presently uncommon after mitral valve
replacement, suture line disruption still occurs and may be significant in
some patients. Suture technique is obviously an important factor in
preventing disruption, but few authors have examined this variable. The
purpose of this study was to determine which of four suture methods for
mitral valve replacement maximized prosthetic stability in the mitral
anulus. Horizontal mattress sutures with subannular pledgets, horizontal
mattress sutures with supra-annular pledgets, figure-of- eight sutures, and
interrupted simple sutures were compared. A Carpentier-Edwards sewing ring
was sutured to the mitral anulus of intact canine left ventricles, each
technique randomly assigned to eight hearts. Suture size, number of bites,
and annular depth were maintained constant in all groups. Progressively
increasing force was applied across the suture line until disruption
occurred. The yield force at initial suture disruption was measured by a
semiconductor strain-gauge transducer and defined the experimental end
point. Subannular pledget-supported sutures required the greatest force
(38.4 +/- 0.8 N) to produce prosthetic dehiscence and were significantly
more secure than supra-annular pledgets (32.7 +/- 0.5 N). The two suture
techniques in which pledgets were used were better than the nonsupported
sutures, the mean yield force averaging 28.3 +/- 0.3 N for figure-of-eight
and 21.3 +/- 0.7 N for interrupted simple sutures. Although clinical
techniques may vary with prosthetic valve design, surgical preference, or
pathological anatomy, this study suggests that horizontal mattress sutures
with subannular pledgets provide the best prosthetic valve stability during
mitral valve replacement.