FUE Heresy: The True Impact of FUE Follicle Transections on Follicle Survival and Hair Diameter Index Values

Introduction: Transected follicles have shown some ability to regenerate growing hair at a given rate depending on the location of the transection. To date, there has been no examination of the true impact of follicle transection rates given this follicle regeneration. This study attempts to quantify the impact of transections on the actual number of surviving follicles and determine the impact on the cosmetic outcome using the Hair Diameter Index (HDI).1 Method: Follicle transection samples from 29 male patients undergoing FUE were evaluated for the level of transection and the location noted. Results: There were 1,682 transected follicles examined. Approximately 45% of transections were in the middle third and the remainder were split evenly in the upper and lower thirds. Conclusion: Based on the studies showing follicle regeneration, it is estimated that 953, or 57%, of the 1,682 transected follicles would be expected to survive. With the survival of transected follicles, the visual impact of transections may be minimal. Using the equation for the HDI calculation, the result suggests that a transection rate of 32% would only start to make a significant visual difference in the transplant density. It is apparent that transections should be minimized, but great efforts should be made to prevent factors such as desiccation and handling trauma, which can harm a significant number of follicles, as these factors may have a greater role in the cosmetic outcome of an FUE procedure.