The Anatomy Analyses And Clinical Application Of Proximal Peroneal Artery Perforators In Free Fibular Flap Based On Computed Tomographic Angiography

Background:Nowadays,vascularized free fibular flap has become the workhorse skin flap for repairing oral and maxillofacial complex tissue defects,because the flap can provide enough volume of bone and can freely carry a skin island.The preparation of free fibular flap is based on the following anatomical basis: the fibular segment is supplied by nutrient and arcuate arteries of the peroneal artery,and the skin island is supplied by the peroneal artery skin perforating branch.Yu et al observed and named 2 distinct groups of perforators as the proximal and distal perforators along the long axis of the fibula bone based on their distribution.To date,most of perforating branches of the skin island carried by the free fibular flap are the distal perforators of the peroneal artery.However,the absence of the distal perforating branch or intraoperative injury of it often leads to the loss of the skin island,and therefore only an isolated free fibular flap can be prepared.The free fibular flap without skin island not only does not have skin island as an observation window,but also cannot fix the complex composite defect with a large soft tissue defect,in this situation,consideration should also be given to explore the contralateral lower limb or raise another soft tissue flap,which will lead to a second donor site or even the need for microvascular anastomosis of double sets of blood vessels.Objectives:This study aimed to ascertain the anatomic features of the proximal peroneal perforators based on CTA.The second aim was to evaluate the contribution of the proximal perforators to the evolution of the conventional fibula free flap.Methods:From September 2018 to September 2020,our research team recruited 24 oral cancer patients who were willing to undergo extensive resection of the primary disease followed by immediate repair with vascularized free fibular flap.Preoperative CTA examination was performed to record the presence,numbers,locations and variations of perforator branches,in which either proximal or distal perforator was counted.For cases with the absence of distal perforator branch or the need for free fibular flap to carry dual–skin paddle,a preoperative design was performed including a skin paddle supplied by the proximal perforator in a free fibular flap or a double island free fibular flap.The operative data of clinical cases,in which the proximal perforator was utilized in fibula free flap reconstruction,were collected and reviewed.Result:1.In the 48 cases of lower limbs,81.25% of the proximal peroneal artery perforating branches were found.In addition,10.42% of the proximal peroneal artery perforating branches originated from the tibiofibular trunk or the bifurcation of the tibiofibular artery,and about8.33% of the proximal peroneal artery perforating branches did not exist.2.The perforating fulcrum of the proximal peroneal artery on the skin of the leg is distributed in the upper part of the leg 1/7-1/2,mainly distributed in 1/4-1/2;3.The proximal perforator branches of the left and right peroneal arteries were symmetrically distributed in 75% of patients.4.Among the 24 patients,one patient had the absence of distal perforator branch,which was repaired by preparing free fibular flap carrying the proximal perforator skin paddle.One patients had mandibular defects with through-and-through buccal defects;one patient had mandibular defects with complex defects of tongue,floor of mouth and gingiva,which were repaired by free fibular flaps carrying dual–skin paddle with proximally and distally based perforators.Conclusion:The presence rate of proximal peroneal perforator is high in the examined population,and the anatomical position is relatively stable.In the case of absence of distal peroneal perforator or intraoperative injury of it,the proximal peroneal perforator can be used as the standby Results:perforator to prepare free fibula osteal flap with proximal peroneal perforator skin paddle.For proximal peroneal perforators originated in the common trunk of the posterior tibial artery and the peroneal artery,or originated in the bifurcation of the posterior tibial artery and the peroneal artery,we can also raise separate free fibula osteal flap and proximal peroneal perforator skin paddle,respectively.In the circumstances,we can reconstruct the composite defects by either forming a chain flap or anastomosing double set of blood vessels,in this way we can avoid opening a second donor site,which will reduce additional injury.For patients with hard tissue defects with through-and-through or complex composite soft tissue defects,chemic free fibular flaps carrying with proximally and distally based perforators can be prepared for repair.