Determining Safe Excision Limits in FUE: Factors That Affect and a Simple Way to Maintain Aesthetic Donor Density

In 2018, researchers investigated the factors that influence the aesthetic donor density in Follicular Unit Excision (FUE) hair transplant procedures. They found that the safe limit for hair follicle extraction was influenced by factors such as the patient's hair density, hair characteristics, and the size of the extraction tool. They proposed a method to maintain aesthetic donor density, which involved calculating the safe extraction limit based on the patient's specific characteristics. The researchers suggested that a safe single pass excision density could range from 10-25 FU/cm2, while the minimum residual donor FU density necessary for satisfactory donor area coverage after one or more surgeries could range from 40-50 FU/cm2. They concluded that while there is no single mathematical algorithm to incorporate all of the factors that contribute to donor area density, a weighted system may be possible to further enhance our ability to predict safe excision and residual donor densities.