Blood-flow velocity as a factor in postoperative microvascular patency

Area of Science:

• Microsurgery
• Vascular Biology
• Surgical Innovation

Background:

• Assessing factors influencing microvascular patency is crucial for successful microsurgical outcomes.
• Existing animal models may not adequately replicate variable blood flow conditions encountered in clinical practice.

Purpose of the Study:

• To develop and validate a novel, reproducible animal model for studying variable blood flow velocity in small vessels.
• To investigate the impact of altered blood flow velocities on the patency rates of 1- to 2-mm vessels following microsurgical procedures.

Main Methods:

• A Sprague-Dawley rat model was created by ligating the femoral artery to induce high or low blood flow states to an epigastric artery flap.
• Blood flow velocities were measured using a microvascular flowmeter, and patency rates were assessed after primary anastomosis and interpositional vein grafting.
• Surgical procedures were repeated by a senior microsurgeon to evaluate the effect of experience.

Main Results:

• The animal model reliably produced distinct high (3.98 ml/min) and low (2.14 ml/min) blood flow groups, confirmed by flowmetry and statistical analysis.
• Decreased blood flow velocity did not significantly impact the patency rates of small vessels after primary anastomosis or vein grafting in experienced hands.
• The study found that proper microsurgical technique, not blood flow velocity, is the primary determinant of patency in 1-mm vessels.

Conclusions:

• The developed animal model is effective for studying small-vessel blood flow dynamics.
• Blood flow velocity is not a significant factor in the patency of small vessels after successful microsurgical anastomoses or vein grafts.
• Microsurgical technique is paramount for ensuring vessel patency, irrespective of moderate reductions in blood flow velocity.