Effect of flush-perfusion on vascular endothelial and smooth muscle function

Area of Science:

• Vascular surgery
• Organ preservation
• Cardiothoracic research

Background:

• Assessing arterial tolerance to perfusion pressure is crucial for surgical outcomes.
• Endothelium-dependent relaxation (EDR) and vascular contractility are key indicators of arterial health.

Purpose of the Study:

• To determine the maximum perfusion pressure arteries can withstand without compromising EDR and contractility.
• To evaluate the impact of St. Thomas' Hospital cardioplegic (STHC) solution on arterial function under varying pressures.

Main Methods:

• Rat abdominal aortas were flush-perfused with STHC solution (with or without dextran 40) at pressures of 50, 100, or 150 mm Hg.
• Vessels were also subjected to distension pressures (50-300 mm Hg) with saline or STHC solution at different temperatures.
• Contractility and EDR were assessed using U-46619 and acetylcholine, respectively.

Main Results:

• Perfusion at 50 or 100 mm Hg for up to 5 minutes did not affect contractility or EDR.
• A pressure of 150 mm Hg for 5 minutes significantly reduced contractility (53%) and EDR (7%).
• Distention at 300 mm Hg severely impaired contractility, with recovery observed only after 30 days.

Conclusions:

• Cold STHC solution is safe for arterial perfusion at pressures up to 100 mm Hg.
• Perfusion pressures of 150 mm Hg or higher can lead to significant impairment of vascular function.
• Arterial function can recover after short-term pressure-induced damage, but high-pressure insults require longer recovery periods.