Ex Vivo Machine Thrombolysis Reduces Rethrombosis Rates in Salvaged Thrombosed Myocutaneous Flaps in Swine

Area of Science:

• Microsurgery
• Vascular Surgery
• Regenerative Medicine

Background:

• Thrombotic complications occur in 2-5% of microsurgical reconstructions.
• Current thrombolytic therapy has limited salvage rates (60-70%) and risks bleeding complications (2-6%).
• Machine perfusion offers a novel approach to deliver thrombolytic agents, potentially reducing complications.

Purpose of the Study:

• To compare flap salvage outcomes between machine perfusion thrombolysis and manual tissue plasminogen activator flush.
• To evaluate the efficacy of machine perfusion in reducing thrombotic complications during microsurgical reconstruction.

Main Methods:

• Bilateral rectus abdominis flaps were harvested from 8 pigs, and thrombosis was induced.
• Flaps were treated with either 2 hours of machine perfusion thrombolysis or intra-arterial manual injection of tissue plasminogen activator.
• Near-infrared fluorescence angiography and muscle biopsy were used to assess perfusion and ischemia/reperfusion injury.

Main Results:

• The machine perfusion group showed a significantly lower incidence of secondary thrombosis (0 vs. 6, p < 0.001) and no flap failures.
• Mean fluorescence intensity, indicating tissue perfusion, was significantly higher in the perfusion group (24.6 vs. 13.0, p < 0.001).
• Muscle injury scores were comparable between groups (7.5 ± 1.5).

Conclusions:

• Machine perfusion thrombolysis demonstrated superior flap salvage rates and reduced secondary thrombosis compared to manual injection in a porcine model.
• Ex vivo machine perfusion allows localized thrombolysis without systemic complications, improving outcomes for compromised tissues.