One-Stage Procedure Using Free Internal Oblique Muscle of the Abdomen Flap for Longstanding Facial Paralysis

Background The transplantation of a free muscle flap represents a trusted method for restoring function and movement in paralyzed facial muscles. However, the choice of donor site is still controversial and can lead to many problems. Discovering appropriate muscle flap sources can effectively mitigate these problems, offering a wider array of options and novel approaches for treating facial paralysis. Methods We dissected 11 cadavers to demonstrate the anatomical relationship of the internal oblique muscle of abdomen. Subsequently, 13 patients with long-term facial paralysis (duration > 12 months) underwent free muscle flap transplantation. The outcomes were assessed using eFACE software. Results All subjects demonstrated spontaneous activity of the transplanted muscle, and reconstruction of facial expression muscle function was achieved to varying degrees in all instances. In the results of eFACE, significant differences were noted in both static and dynamic facial scoring between pre and postoperative assessments. Conclusions Capitalizing on the abundant vascular and neural supply of the internal oblique muscle, a novel surgical technique involving ultralong anastomosis of multiple vascular and neural pedicles of the internal oblique muscle flap in cross-facial transplantation has been designed to treat late-stage facial paralysis. Long-term follow-up of postoperative patients shows significant improvement in facial static symmetry, restoration of facial expression muscle function, and assistance in the revival of eyelid closure capability.