Identifying Factors Affecting Outcomes in Scalp Replantation: A Systematic Review of the Literature.

Background:  Replantation is the ideal treatment in traumatic scalp defects to provide immediate coverage with restoration of hair-bearing skin. However, data are limited to case reports and small case series. Comprehensive analysis of techniques and outcomes is not available. Our aim was to systematically analyze the available literature to better understand management and postoperative outcomes of patients undergoing scalp replantation.

Methods:  A systematic review of the PubMed, Cochrane, and EBSCO databases was performed in October 2019. Search terms included "replantation," "replant," "revascularized," "revascularization," "avulsion," and "scalp." Only papers reporting microvascular replantation of completely avulsed scalps, including case reports, were included. Review articles, non-English language articles, articles discussing nonreplant coverage, incomplete scalp avulsions, and articles discussing delayed scalp replantation were excluded. Data extracted included demographics, percent of scalp affected, mechanism, operative technique, and postoperative outcomes. Statistical analysis was performed using Mann-Whitney U tests, Kruskal-Wallis, and chi-squared tests.

Results:  From a total of 704 initial results, 61 studies were included for analysis comprising 149 scalps. Complete survival was achieved in 54.7%, partial survival in 38.9%, and failure in 6.7%. Total ischemia time greater than 12 hours was associated with complete replant failure. Arterial anastomoses appeared to protect against complete loss. The number of venous repairs, proportion of venous-to-arterial repairs, use of vein grafts, thromboprophylaxis, or intraoperative complications did not affect outcomes. Patients required significant volumes of blood products, which was associated with partial success. Salvage rate after unplanned return to the operating room was 60.0%. Normal hair growth was achieved in all surviving native scalp tissue.

Conclusion:  Scalp replantations, while technically challenging, are the ideal treatment for scalp avulsions. Fortunately, these have high rates of success. And as a focal point of a patient's appearance, this is invaluable in restoration of a sense of normalcy.