Coverage of elbow and forearm soft tissue defects with the posterior ulnar recurrent artery perforator flap (PURAP): an anatomical study

Introduction Covering soft tissue defects from the elbow and forearm is challenging for the plastic surgeon. The posterior ulnar recurrent artery perforator flap is a fasciocutaneous perforator flap vascularized by the perforators emerging from the posterior ulnar recurrent artery. It has multiple functional and aesthetic advantages but has not yet been well studied. This work aimed to examine the number, caliber, and topography of the posterior ulnar recurrent artery's perforators. Methods Perforator mapping was performed by blue latex injection on 20 fresh cadavers' upper extremities. Thermal mapping by TIRD was used to identify the "hot spots" of these perforators, and the 4D vascular network of the ulnar recurrent artery was scanned. The preoperative design and dissection of the flap were adapted based on the results of this anatomical study. A case study was performed to illustrate the clinical application. Results On average, we located 7.7 +/- 1.7 perforators per upper extremity with an average caliber of 0.77 +/- 0.19 mm (3.5 +/- 1.2 in the forearm and 4.2 +/- 1.5 in the arm). On average, the arm perforators were located 3.2 +/- 1.6 cm proximally from the medial epicondyle. Thermal mapping showed three perforator "hot spots," two in the forearm (directly at the artery origin level and one more posteriorly) and one in the arm. The 4D CT reconstructions allowed us to estimate the vascular territory at the level of the medial epicondyle and the distal half of the medial aspect of the arm, as well as the ascending course of the artery. Conclusion The posterior ulnar recurrent artery perforator flap can be harvested efficiently and reliably, as the posterior ulnar recurrent artery has constant perforators, especially around 3 cm proximal to the medial epicondyle. This reinforces this flap's status as a potential elbow and forearm tissue defect coverage alternative.