A Practical Tip for Marking the Vascular Pedicle of a Free Flap

The introduction of microvascular reconstruction was among the most significant advances in plastic surgery in the twentieth century, and continued refinement of these techniques has allowed for reliable reconstruction of virtually any area of the body.[1]

Free flap procedures have become the gold standard reconstruction for many defects especially the lower limb, breast, and head and neck.

In free tissue transfer, there is a significant risk of mistaking the artery for the vein (and vice versa) that would result in failure of the flap if not immediately recognized and corrected.[2] A two-team approach is becoming more normal practice in such procedures to reduce the operative time and improve efficiency. This could, however, increase the risk of misidentifying the venous and arterial vessels within the pedicle when the flap is detached and passed from the donor site to recipient.

Many ways are well known to differentiate between the artery and the vein intraoperatively:

• Visualizing blood draining from the vein

• Difference in wall thickness between artery and vein

• Presence of valves and communicating branches between the two venae comitantes.[3]

However, these differences can be fairly subtle to the less experienced microsurgeon, or due to anatomical variations within the pedicle of the flap.

In this article, we propose a simple tip to mark the vascular pedicle that is considered standard practice in our unit and is a universal language to communicate between the flap raising and the flap insetting team.

In our practice, when we divide the flap, we leave one ligation clip on the flap side of the artery and leave the venae comitantes open ([Fig. 1]).

Fig. 1 Schematic of the marking of the arteries and the veins for free flap reconstruction using Ligaclips.

This gives the following benefits:

• To drain the blood from the flap and prevent blood from pooling inside the flap, increasing the risk of thrombosis.

• In our unit, we prefer to anastomose the vein and remove the microclamps before anastomosing the artery to reduce time the vessels are clamped and reduce the risk of stasis across the anastomoses. Not placing a ligation clip on the vein leaves it ready for anastomosis.[4]

• When the anastomoses are completed, and the clamps are removed, it is possible to confirm venous outflow from the open end of the second vein (if present), before ligating.

• The orientation of the open or closed end of the Ligaclip, along with the relative position of the artery to the vein, then you will know how the pedicle was oriented in situ that is especially true in perforator flaps.

This marking pattern is standard protocol within our unit, which makes communication between the team members simple and avoids the mistake of anastomosing artery to the vein.

In our practice of over 1,000 flaps over the past 5 years, we have successfully managed to standardize this protocol across all members of the team and avoid technical errors that could compromise the success of the reconstruction.

Publication History

Article published online:
17 September 2020

• References

• 1 Shum JW, Melville JC, Couey M. Preparation of the neck for advanced flap reconstruction. Oral Maxillofac Surg Clin North Am 2019; 31 (04) 637-646
• 2 Banerjee D, Fusco D, Green J, Eapen G, Kasirajan V. Avoidable errors in cardiac surgery: anastomosis of the left internal mammary artery to a vein. Ann Thorac Surg 2005; 79 (05) 1769-1771
• 3 Wei F, Mardini S. Flaps and Reconstructive Surgery. 2nd edition. United States: Elsevier 2016
• 4 Braün SA, Mine R, Syed SA. et al. The optimal sequence of microvascular repair during prolonged clamping in free flap transfer. Plast Reconstr Surg 2003; 111 (01) 233-241