Reverse tapered vs. straight PTFE (Gore-Tex) grafts in dogs

Area of Science:

• Vascular Surgery
• Biomedical Engineering
• Materials Science

Background:

• Reversed Autogenous Saphenous Vein (RASV) is the preferred graft for infrainguinal arterial bypass.
• RASV possesses a unique reverse tapered (RT) geometric configuration not found in synthetic grafts.

Purpose of the Study:

• To evaluate the performance of a reverse tapered synthetic graft (RTG) against a straight synthetic graft (SG).
• To investigate the impact of graft geometry on patency and thrombus formation in arterial bypass models.

Main Methods:

• Implantation of 6 mm straight PTFE grafts (SG) and 4-7 mm reverse tapered PTFE grafts (RTG) in the aorto-iliac position of 16 mongrel dogs.
• Assessment of graft patency, anastomotic thrombus, and midgraft thrombus deposition in surviving canine subjects.

Main Results:

• RTGs demonstrated significantly higher absolute patency rates (64%) compared to SGs (36%) (P=0.05).
• RTGs exhibited less anastomotic thrombus formation (43%) than SGs (71%) (P=0.05).
• RTGs showed significantly reduced midgraft thrombus deposition compared to SGs (P=0.025).

Conclusions:

• The reverse tapered configuration significantly enhances graft performance in terms of patency and thrombus reduction.
• The RT geometric design merits further clinical investigation for vascular bypass applications using various materials.
• This study supports exploring the RT configuration in different species and with alternative graft materials.