Vena cava replacement with a peritoneum-lined vascular graft

Area of Science:

• Biomaterials Science
• Vascular Surgery
• Regenerative Medicine

Background:

• The peritoneum's mesothelium possesses fibrinolytic properties, making it a potential candidate for vascular conduits.
• Polytetrafluoroethylene (PTFE) grafts are commonly used but prone to thrombosis.
• Investigating novel graft materials is crucial for improving vascular reconstruction outcomes.

Purpose of the Study:

• To evaluate the efficacy of peritoneum-lined polytetrafluoroethylene (PTFE) grafts as venous conduits in a canine model.
• To assess the patency rates and histological characteristics of peritoneal, PTFE, and peritoneum-lined PTFE grafts.
• To determine if the inherent fibrinolytic properties of the peritoneum enhance graft performance.

Main Methods:

• A canine model was used to replace the infrarenal inferior vena cava with 2 cm interposition grafts.
• Graft types included peritoneal tubes, PTFE, and PTFE lined with peritoneum.
• Venograms and explant microscopy (light and scanning electron) were performed at 1 and 6 weeks post-implantation.

Main Results:

• Graft area reduction at 1 week predicted 6-week patency for all graft types.
• At 6 weeks, patency rates were: peritoneal tube (33%), PTFE (86%), and lined graft (57%).
• PTFE grafts showed stenosis due to thrombus; lined grafts showed stenosis from granulation tissue. Lined grafts had a cellular lining and no thrombus, unlike PTFE grafts.

Conclusions:

• Peritoneum-lined PTFE grafts develop a cellular lining but do not offer improved short-term patency compared to standard PTFE grafts.
• The mechanism of stenosis differs between PTFE and lined grafts, involving thrombus formation versus granulation tissue.
• While the peritoneum provides a cellular lining, its fibrinolytic potential did not translate to superior short-term patency in this model.