[Imaging study and clinical application of peroneal perforating chimeric tissue flap].

Objective: To explore the feasibility of peroneal perforating chimeric tissue flap in repairing the composite defects of calf and heel based on lower limb angiography, and the clinical effect. Methods: The digital subtraction angiography images of lower limbs of 50 patients met the selection criteria between May 2011 and October 2014 were used as the research object to observe the course of peroneal artery and its perforating vessels. Based on the observation results, between April 2015 and October 2020, the peroneal perforating chimeric tissue flap was designed to repair 7 cases of composite defects of the calf and heel. There were 5 males and 2 females with an average age of 38 years (range, 25-55 years). The causes of injury included traffic accident in 4 cases, falling from height in 2 cases, and machine strangulation in 1 case. There were 5 cases of calf skin defect and tibial defect. The size of skin defect ranged from 5 cm×3 cm to 11 cm×7 cm, and the length of bone defect was 5-8 cm. There were 2 cases of heel skin defect and calcaneal defect. The sizes of skin defects were 5.0 cm×4.0 cm and 7.5 cm×6.5 cm, and the bone defects were 3.0 cm×2.6 cm and 4.0 cm× 3.0 cm. For the calf defect, the size of skin flap ranged from 6 cm×4 cm to 12 cm×8 cm, and the length of the fibula was the same as that of the tibial defect. For the heel defect, the sizes of the skin flaps were 8.5 cm×5.5 cm and 13.0 cm×5.0 cm, and the lengths of the fibulae were 10 cm and 12 cm. Free transplantation was performed in 5 cases and pedicle transplantation in 2 cases. The wound at donor site was repaired with skin grafting or sutured directly. Results: The peroneal artery ran close to the fibula 7.25-8.40 cm below the fibula head and send out 5-7 perforating vessels, with an average of 6.5 vessels. Perforating vessels mainly appeared in four places, which were (9.75±0.91), (13.21±0.74), (18.15±1.22), and (21.40±0.75) cm below the fibular head, with the occurrence rates of 94%, 90%, 96%, and 88%, respectively. Clinical application of 7 cases of peroneal perforating chimeric tissue flap all survived, all wounds healed by first intention. The skin graft at donor site survived and the incision healed by first intention. All patients were followed up 6-36 months, with an average of 12 months. Peroneal perforator chimeric tissue flap had good shape and soft texture. X-ray films showed that the bone graft healed well, and the healing time was 6-11 months (mean, 7 months). No obvious bone resorption was observed during follow-up. Five patients had no pain when walking, and 1 had mild pain with claudication. Postoperative heel ulcers formed in 1 case and healed after wearing custom plantar pressure dispersing shoes. At 6 months after operation, 2 patients were rated as grade Ⅳ and 5 patients as grade Ⅴ according to Holden walking function score. Conclusion: The peroneal perforating vessel distribution is constant and the peroneal perforating chimeric tissue flap is safe and reliable for repairing the composite defects of calf and heel.