Histologic Evaluation of Dacron® and PTFE Graft Material Explanted From Humans After 4 to 20 Years In Vivo

Abstract

The objective of this study was to evaluate long-term integrity of knitted Dacron® and polytetrafluoroethylene (PTFE), as used in arterial prostheses, 4 to 20 years following graft implantation in patients. Graft durability following prosthetic graft placement is a frequently asked question from patients. In an effort to make a determination, the authors surgically obtained representative specimens of grafts clinically implanted 4 to 20 years before graft retrieval for histopathologic study. Eleven prosthetic arterial grafts, seven Dacron® and four PTFE, were retrieved from 10 patients and stained for study using paraffin-embedded histology sections. These were examined with light microscopy and polarized light microscopy. Graft specimens were taken, which prompted graft exploration and retrieval; these included thrombosis, stenosis, graft infection, and pseudoaneurysmal formation. No loss of integrity, fragmentation, or distortion of Dacron® or PTFE graft material was detected. Normal foreign-body reactions and healing with fibrosis were noted within the interstices of the Dacron® grafts and outer surfaces of Dacron® and PTFE grafts. No evidence of resorption or biodegradation was noted in any graft. Pseudointima was present on the luminal surface of Dacron® but not of PTFE grafts. Although no atherosclerotic changes were identified in the Dacron® grafts, focal areas of dystrophic calcification were present within the interstices of the PTFE grafts. The longterm (4 to 20 years) in vivo structural integrity of the Dacron® and PTFE grafts studied is supported by our data. Whereas the foreign-body reaction macrophages and foreign-body giant cells of the material interface have the potential to resorb or biograde the material, data in these studies suggest Dacron® and PTFE are resistant to biodegradation for at least two decades. These data support the continued use of these materials in fabrication of arterial prostheses.

Association of systemic antibody response against polyethylene terephthalate with inflammatory serum cytokine profile following implantation of differently coated vascular prostheses in a rat animal model

“…Comparable observations were also reported by other authors following implantation of discs made from PET and ePTFE into the subcutaneous and adipose tissue of rats for 3 and 5 weeks 40 . Furthermore, this is consistent with earlier observations published by Blumenberg et al following a histologic evaluation of seven PET and four PTFE grafts which were explanted from humans after a period of 4–20 years, demonstrating a foreign‐body reaction reflected by macrophages and foreign‐body giant cells predominantly at the outer capsule interface and within the interstices of the PET grafts but only to some or minimal extent of the PTFE grafts 41 …”

Mechanical Testing Device for Viscoelastic Biomaterials

“…Since the fluorocarbon polytetrafluoroethylene (PTFE) has been used for vascular grafts this material is a logical choice to validate the effectiveness of the device before attempting to work with actual biologic specimens. 13,14 Furthermore Transient data on two other polymers are analyzed as well via the Fourier transform to investigate the feasibility of the technique. These materials were not tested in the device;…”

“…In fact, it has been used for vascular grafts in patients who have been victims of various traumas. 13,14 DuPont data shows that relaxation time for this material is on the order of minutes. 12 So if the displacement occurs within one second then the relaxation time is at least two orders of magnitude larger.…”

In situ Evolution of the Mechanical Properties of Stretchable and Non-Stretchable ePTFE Vascular Grafts and Adjacent Native Vessels

“…However, although Dacron and ePTFE are considered biologically stable, even in these grafts dilatation is commonly reported, probably due to the degenerative effect of tissue fluids and enzymes (14). Specifically for ePTFE, Schröder et al (15) investigated over 100 patients with ePTFE grafts with both computerized tomography (CT) and ultrasound (US), and noted a significant dilatation in graft diameter (12.5%), especially in the first three months after implantation.…”