Free fat flap transfer in recurrent neurogenic thoracic outlet syndrome pain treatment: FIRST observational pilot study.

Background: Neurogenic thoracic outlet syndrome (NTOS), characterized by brachial plexus compression, causes chronic pain and numbness in the upper extremities. Recurrences are common after surgical treatment, which typically includes an anterior scalenectomy and rib resection. Brachial plexus neurolysis and flap coverage can reduce scar fibrosis and prevent further recurrence. The latissimus dorsi flap is a common choice for this purpose. However, perforator fat flaps minimize donor site complications by avoiding muscle harvesting. Furthermore, a free flap transfer prevents new scars from developing in an already painful anatomical region. Given the lack of literature on this subject, we plan to use validated and recommended questionnaires to investigate the impact on pain and quality of life of brachial plexus wrapping with a free fat flap following neurolysis in cases of recurrent NTOS.

Methods: FIRST is a single-center, prospective observational pilot study recruiting participants over 24 months. Eligible patients over the age of 18 are treated with brachial plexus neurolysis and a free perforator fat flap for recurrent NTOS. The study aims to enroll 20 patients and involves preoperative and postoperative assessments at a six-month follow-up. The primary outcome, measured using numerical scales, is pain reduction. Secondary outcomes include decreased painful body surface area, maximum and average pain levels, changes in quality of life, upper limb function, and anxiety-depressive symptoms, which are measured using various validated scales and questionnaires.

Discussion: This study will provide insight into the efficacy of free perforator fat flaps in recurrent NTOS using standardized, validated assessments for neuropathic pain, including psychosocial aspects. By providing vascularization around the brachial plexus, fat flaps may reduce inflammation, fibrosis, and perineural scar adhesions, thereby alleviating pain. This technique also avoids extensive local dissection required for regional flaps and reduces donor site morbidity. Potential limitations include the technical complexity of free flap surgery.