A Scoping Review on Complications in Modern Hair Transplantation: More than Just Splitting Hairs.

[BACKGROUND] Hair restoration surgery (HRS) is a commonly performed elective procedure but to date lacks a review of the full scope of complications.

[OBJECTIVES] To provide a comprehensive overview of observed complications associated with follicular unit extraction (FUE) and follicular unit transplantation (FUT).

[ELIGIBILITY CRITERIA] Randomized control trials, cohort studies, case series, and case reports published in 1985 or later on adults (age>18). Nontraumatic or autoimmune etiologies of alopecia were excluded as procedure indications.

[SOURCES OF EVIDENCE] PubMed, EMBASE, Cochrane databases (last search December 31, 2022).

[CHARTING METHODS] Data-charting and extraction were independently performed with two reviewers using Covidence.

[RESULTS] Forty-three publications were included. Two large series reported the overall complication rate to be 1.2 and 4.7%. Common complications included bleeding requiring intervention (up to 8%), persistent numbness (up to 11%), infection (up to 11% with two reports of Kaposi varicelliform eruptions and one of mucormycosis), effluvium at donor and recipient sites (up to 4.1% and 6.5%, respectively). The most common donor-site complication was hypertrophic scarring/keloid formation after FUT (up to 15.1%). Complications at the recipient site, including crusting (up to 54.8%), frontal edema (up to 50%), and sterile folliculitis (up to 53.3%), tended to be poorly defined with a broad range of incidences.

[CONCLUSION] Serious complications associated with HRS are rare in the hands of experienced providers. However, comprehensive discussions of risk must be had with prospective patients as any complication in the context of an elective procedure may be significant and psychologically devastating for the individual patient.

[LEVEL OF EVIDENCE V] This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .