European Journal of Cardio-Thoracic Surgery, Vol 4, 191-196, Copyright © 1990 by European Association for Cardio-thoracic Surgery
Quantitative analysis of neovascularization of different PTFE-implants
MD Menger, P Walter, F Hammersen and K Messmer
Department of General Surgery, University of Saarland, Homburg/Saar.
The process of neovascularization was analyzed in vivo in different
expanded polytetrafluoroethylene (e-PTFE) implants which are frequently
used in cardio-thoracic and vascular surgery. We have used the model of the
hamster dorsal skinfold chamber which allows quantitative analysis of the
microcirculation by means of intravital fluorescence microscopy. Pieces of
approximately 1 mm2 of the cardiovascular patch (CVP, fibril length: 30
microns; n = 21), surgical membrane (SM, fibril length: 1 micron; n = 16),
and soft tissue patch (STP, fibril length: 22 microns; n = 12) were
implanted into the skinfold chambers. On day 10 after implantation, the
functional density of newly formed microvessels was significantly (P less
than 0.05) higher in CVP (145.0 +/- 10.9 cm-1) as compared to SM (688 +/-
13.9 cm-1) and STP (86.9 +/- 21.2 cm-1). In addition, CVP revealed a larger
zone of neovascularization (311.6 +/- 19.4 microns) and the tightest
integration (dynamic breaking strength: 17.9 +/- 3.0 cN/mm2) into the
perigraft tissue, while SM demonstrated only few microvessels and no
integration (6.0 +/- 1.9 cN/mm2) into the perigraft. None of the three
different PTFE-implants revealed transmural ingrowth of capillaries. The
internodal distance of PTFE implants seems to be the most important factor
for neovascularization. Surgical membrane used for the replacement of
passive biological membranes demonstrated, as is its purpose, little
neovascularization and no integration into the perigraft tissue.(ABSTRACT
TRUNCATED AT 250 WORDS)
