The effect of autoclave resterilisation on polyester vascular grafts.
OBJECTIVE
polyester grafts are expensive, single-use items. Some manufacturers of uncoated, woven grafts include instructions for autoclave resterilisation to be performed at the surgeon's own request. Others warn against such manipulation. Theoretically, the glass transition point of polyester at 70-80 degrees C and the possible acceleration of hydrolysis suggest that autoclave resterilisation at 135 degrees C might be a problem.


METHODS
a DeBakey Soft Woven Dacron Vascular Prosthesis (Bard) and a Woven Double Velour Dacron Graft (Meadox) were autoclave-resterilised 0 to 20 times, having been weighed before and after sterilisation. Tactile testing was performed. Mechanical properties were examined by probe puncture and single-filament testing, the surface was examined by scanning electron microscopy and the degree of hydrolysis by infra-red spectroscopy.


RESULTS
tactile testing revealed a change of feeling with increasing cycles of resterilisation. Investigation of weight, textile strength, single-filament strength, electron microscopy of the surface and infra-red spectroscopy showed no change of the material.


CONCLUSIONS
changes felt are presumably a surface phenomenon, not measurably affecting strength or chemistry of material after autoclave resterilisation. We therefore feel that it is safe to use once-autoclave-resterilised surplus uncoated polyester grafts, provided that sterility is guaranteed.
Riepe
G
G
Department of General, Vascular and Thoracic Surgery, General Hospital of Hamburg-Harburg, Germany.
Whiteley
M S
MS
Wente
A
A
Rogge
A
A
Schröder
A
A
Galland
R B
RB
Imig
H
H
D001807:Blood Vessel Prosthesis / Q000706:statistics & numerical data; D006801:Humans; D008422:Materials Testing / Q000379:methods; D008855:Microscopy, Electron, Scanning; D011093:Polyethylene Terephthalates / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013227:Steam; D013242:Sterilization / Q000379:methods* / Q000706:statistics & numerical data; D013499:Surface Properties
D011093:Polyethylene Terephthalates; D013227:Steam