Evidence-Based Integrated Protocol to Maximize Hair Follicle Survival in Follicular Unit Extraction (FUE)

Follicular unit extraction (FUE) is a widely used surgical technique for hair restoration, yet hair follicle survival rates vary depending on surgical instrumentation, graft handling, and perioperative care. The purpose of this clinical trial is to evaluate whether an evidence-based, integrated perioperative protocol maximizes hair follicle graft survival compared with standard departmental practice in male patients undergoing FUE for androgenetic alopecia or localized scarring alopecia. Participants will be randomly assigned to one of two groups: * Integrated Protocol Group: Patients receive FUE surgery guided by a standardized workflow featuring algorithmic punch selection (0.8-1.0 mm), pre-set extraction depth and angulation, chilled holding solutions maintained at 4 °C, strict graft out-of-body time limits (target ≤2-4 hours), and standardized recipient site implantation. * Standard FUE Practice Group: Patients receive FUE surgery according to routine departmental practice, where punch selection, harvesting parameters, and graft handling follow the operating surgeon's standard routine. Follicle survival and hair density will be tracked using digital trichoscopy in pre-marked 1×1 cm reference scalp areas over a 12-month follow-up period. Investigators will also assess intraoperative follicular transection rates, procedural complications, and patient satisfaction between the two groups.

Inclusion Criteria: * Male patients aged 18 to 60 years. * Clinically diagnosed androgenetic alopecia (Norwood-Hamilton grade II-V) or localized scarring alopecia suitable for follicular unit extraction (FUE). * Adequate donor area hair density (≥ 40 FU/cm²) confirmed by trichoscopic evaluation. * Minimal or no response to at least 6 months of medical treatment (e.g., topical minoxidil, oral finasteride), where applicable. * General good health with no contraindications to minor outpatient surgery under local anesthesia. * Willingness and ability to provide written informed consent and comply with the full 12-month follow-up schedule. Exclusion Criteria: * Active scalp infection, dermatitis, or other active dermatological disease at the donor or recipient site. * History or tendency of keloid or hypertrophic scarring. * Bleeding diathesis or current use of anticoagulant/antiplatelet therapy that cannot be safely discontinued. * Uncontrolled systemic disease (e.g., uncontrolled diabetes mellitus, cardiovascular, hepatic, renal, or pulmonary disease). * Immunosuppression or current use of immunosuppressive medication. * Endocrine disorders directly causing hair loss (e.g., uncontrolled thyroid disease) or active telogen effluvium. * Psychiatric illness affecting the capacity to provide informed consent or comply with follow-up, or unrealistic patient expectations. * Previous hair transplantation in the same donor or recipient area within the preceding 12 months. * Known hypersensitivity to local anesthetics used in the study.