Some biomechanical considerations of polytetrafluoroethylene sutures
M. C. Dang, J. G. Thacker, J. C. Hwang, G. T. Rodeheaver, S. M. Melton and R. F. Edlich
Department of Plastic Surgery, University of Virginia School of Medicine, Charlottesville 22908.
The biomechanical performance of polytetrafluoroethylene (PTFE) sutures has
been compared with that of polypropylene sutures, the standard to which
other sutures used in vascular and cardiac surgery are compared. The PTFE
is supple and has no plastic memory, while the polypropylene suture is
stiff and retains its plastic memory. In addition, the rate of creep
encountered in the PTFE suture was significantly less than that of the
polypropylene suture. The knotting profiles for knot security for either a
square, granny, or surgeon's knot for polypropylene sutures were three
throws each. In contrast, knot security with either a square or granny PTFE
knot was accomplished with seven throws; six throws were needed for a
secure surgeon's knot. The breaking strength of the unknotted and knotted
PTFE sutures was approximately one half as great as that for the unknotted
and knotted polypropylene sutures. Knot construction significantly reduced
the breaking strength of polypropylene sutures but did not alter the
breaking strength of PTFE sutures. The percent elongation experienced by
both sutures before breakage did not differ significantly. The elasticity,
as measured by work recovery, for the polypropylene suture was greater than
that for the PTFE suture. On the basis of its unique biomechanical
performance characteristics, the PTFE suture should have an important place
in vascular and cardiac surgery.
