Maintaining long-term vessel patency in microvascular surgery using tissue-type plasminogen activator

Area of Science:

• Vascular Surgery
• Thrombosis Research
• Biomedical Engineering

Background:

• Vascular thrombosis at microanastomosis sites is a primary cause of free flap failure.
• Short-term local tissue plasminogen activator (t-PA) infusion effectively lyses thrombi but does not prevent rethrombosis.
• Optimizing thrombolytic therapy is crucial for enhancing free flap success rates.

Purpose of the Study:

• To evaluate the efficacy of a 48-hour continuous local t-PA infusion in maintaining long-term venous patency.
• To investigate the potential of extended thrombolytic therapy to prevent rethrombosis after microvascular procedures.
• To assess the impact of prolonged t-PA infusion on venous graft survival in an animal model.

Main Methods:

• A modified arterial inversion graft model was used in rabbits to induce venous thrombi.
• Three milligrams of t-PA were administered via continuous local infusion over 48 hours to eleven rabbits.
• Venous graft patency was assessed at 48 hours and 1 week post-infusion.

Main Results:

• Seven out of eleven (63.6%) grafts remained patent at 48 hours.
• Four out of eleven (36.4%) grafts remained patent at 1 week.
• Patency rates at 48 hours (p < 0.001) and 7 days (p < 0.05) were statistically significantly higher compared to the historical control group (1/22).

Conclusions:

• Lengthening the infusion time of t-PA may increase the long-term patency rate in this venous thrombosis animal model.
• Continuous 48-hour local t-PA infusion demonstrates improved efficacy in maintaining venous graft patency compared to shorter durations.
• These findings suggest that extended thrombolytic therapy could be a viable strategy to improve outcomes in microvascular surgery.