Intraoperative physiologic blood flow studies in the TRAM flap

Area of Science:

• Plastic Surgery
• Microsurgery
• Vascular Anatomy

Background:

• Transverse rectus abdominis myocutaneous (TRAM) flaps are widely used for breast reconstruction.
• The vascular supply of TRAM flaps, particularly the deep epigastric arterial system, is critical for flap viability.
• Optimizing blood flow is essential to minimize flap necrosis and improve reconstructive outcomes.

Purpose of the Study:

• To investigate the functional and quantitative properties of the blood supply to TRAM flaps.
• To assess the role of the deep epigastric arterial system in TRAM flap perfusion.
• To determine the optimal surgical technique for preserving TRAM flap vascularity.

Main Methods:

• Intraoperative study involving 17 patients undergoing unilateral TRAM flap breast reconstruction.
• Ultrasonic measurement of blood flow in the deep inferior epigastric artery (DIEA).
• Direct measurement of blood pressure in the deep epigastric arterial system after vessel division and with selective arterial occlusion.

Main Results:

• Occlusion of the superior epigastric artery reduced DIEA blood flow by 23% in 71% of patients, indicating a watershed area superior to the umbilicus.
• Blood pressure in the proximal DIEA stump averaged 46% of mean systemic blood pressure.
• Occluding parts of the rectus muscle reduced flap arterial blood pressure by 19% in 80% of patients, highlighting the importance of axial flow preservation.

Conclusions:

• Flap survival necessitates reversal of normal arterial flow direction to ensure adequate perfusion of the lower TRAM flap.
• Harvesting the entire rectus muscle, avoiding muscle-splitting, is supported to maintain axial blood flow.
• These findings advocate for surgical techniques that preserve the integrity of the deep epigastric arterial system for TRAM flap viability.