(30) Vascular Supply to the Fibula Free Flap Skin Paddle: A Three-Dimensional Analysis of the Morphometric Characteristics of the Cutaneous Perforators

Abstract: The fibular free flap (FFF) is commonly used in maxillofacial reconstructive surgery to treat complex defects. There is a lack of comprehensive 3-dimensional (3D) analyses of the morphometric characteristics of the FFF perforators. The purpose of this 3D anatomical study was to: (1) construct high fidelity 3D models of the FFF perforators from origin to skin; (2) determine pedicle length for each cutaneous perforator originating from the peroneal (fibular) artery; (3) quantify circumference and length of each peroneal perforator; (4) quantify circumference of the peroneal artery at its origin; (5) compare the course and morphometric characteristics of the perforators between specimens. Four cadaveric specimens were used in this study. The dissection, digitization and 3D modelling methodology developed in our laboratory was adapted to study the FFF cutaneous perforators. From superficial to deep, serial dissection and digitization was carried out to capture the vessels, muscles and bony structures as found in situ. The specimens were then skeletonized and laser scanned to provide bony landmarking of the peroneal perforators. The digitized Cartesian coordinate data was reconstructed into 3D models using Autodesk® Maya® with plugins developed in the laboratory (Figure 1). The course of each FFF perforator was documented from its origin to the skin. Morphometric characteristics including pedicle length, perforator circumference and length, and peroneal artery circumference at origin were then computed in 3D space. The course and morphometric characteristics were compared between specimens using descriptive statistics. It was determined that the number of peroneal perforators varied from 2–4 per leg and coursed through the soleus and/or flexor hallucis longus to reach the skin. The mean circumference of the peroneal artery at its branching point from the posterior tibial artery was 1.44 ± 0.20 cm (range 1.24–1.68 cm). For each cutaneous perforator arising from the peroneal artery, the mean pedicle length was 9.92 ± 7.47 cm. In specimens with 2 perforators, the proximal perforator had the largest circumference in the first specimen and the distal perforator in the second specimen. In the specimen with 3 perforators, the middle perforator had the smallest circumference, followed by the distal perforator. In the specimen with 4 perforators, the proximal perforator had the largest circumference and the distal the smallest. The most distal perforator had a circumference of 0.50 cm, which may be less viable for adequate perfusion than the more proximal perforators. Overall, the mean circumference of the peroneal perforators was 0.75 ± 0.19 cm (range 0.47–1.07 cm). The mean peroneal perforator length was 8.66 ± 8.25 cm (range 2.03–25.99 cm). In all specimens, the most proximal peroneal perforator had the greatest length from origin to skin. In conclusion, the pedicle length varied depending on the site of origin of the peroneal perforator. The most distal perforators had adequate pedicle length for FFF viability, however, the circumference of the distal most perforator was the smallest in 2 of 4 specimens. Dissection, digitization and 3D modelling enabled visualization and quantification of the cutaneous perforators and their parameters as in situ (Figure 1). A comprehensive understanding of the cutaneous perforator anatomy as in situ, in 3D space, will provide an evidence-based approach to optimize FFF skin paddle design with the goal of improving clinical outcomes. Utilizing cadaveric data will facilitate ultrasonographic localization when identifying viable peroneal perforators.

Lykoudis EG, Koutsouris M, Lykissas MG: Vascular anatomy of the integument of the lateral lower leg: An anatomical study focused on cutaneous perforators and their clinical importance. Plast Reconstr Surg 128: 188, 2011.
Poulet V, Prevost A, Cavallier Z, Alshehri S, Lauwers F, Lopez R: Fibula free flap perforasomes: vascular anatomical study and clinical applications. Surgical and Radiologic Anatomy 44: 637, 2022.
Figure 1. 3D model of a specimen with four cutaneous peroneal perforators. A. Model of superficial dissection showing perforators piercing the soleus. B. Model of deep dissection with soleus removed to show the origin of peroneal perforators relative to the tibia and fibula.