title: Evaluation of survival rate after follicular unit transplantation using the KNU implanter.
abstract: BACKGROUND
  Many hair transplant surgeons have advocated the use of micrograft megasessions for the purpose of a more natural looking end result, especially in the Oriental with higher skin/hair color contrast and darker, coarse, straight hairs. But it also has some fundamental limitations. Most important are a low graft yield and a low density after transplantation. There are several reports about the survival rate of micrografts in Caucasians, though the results are variable, but few reports about the survival rate and fate of micrografts in Orientals.
  
  
  OBJECTIVE
  To compare the survival rate of one-hair follicular units with that of two-hair follicular units using the KNU implanter, to ascertain the average survival rate of micrografts (one- and two-hair follicular units), and to evaluate the fate of grafted hair according to time.
  
  
  METHODS
  Two templates of 1.5 cm2 were made by tattooing on both sides of the frontoparietal recess areas in 11 patients with male pattern baldness (beyond Norwood type IIIa). The authors planted one-hair unit micrografts in the left template and two-hair unit micrografts in the right template, which were prepared by the concept of follicular unit, and counted the surviving number of follicular units at 1 and 3 months and total hairs at 6 and 12 months after transplantation.
  
  
  RESULTS
  The mean survival rate by the number of follicular units was 47.3 and 57.4% at 1 and 3 months after transplantation, respectively. The mean survival rate by the total number of hairs was 92.0 and 90.4% at 6 and 12 months after transplantation, respectively.
  
  
  CONCLUSIONS
  About 50% of the transplanted hairs fell out in 1 month, but at 6 months the survival rate of follicular unit transplantation using the KNU implanter showed a good result (92%), and there were no significant differences in the mean survival rate of follicular unit and total hairs between one-hair and two-hair units at 1, 3, 6, and 12 months after transplantation.
authors.affiliation: Departments of Dermatology and Immunology, Kyungpook National University School of Medicine, Taegu, Korea.
authors.forename: S J
authors.initials: SJ
authors.lastname: Lee
authors.forename: H J
authors.initials: HJ
authors.lastname: Lee
authors.forename: S J
authors.initials: SJ
authors.lastname: Hwang
authors.forename: D W
authors.initials: DW
authors.lastname: Kim
authors.forename: J B
authors.initials: JB
authors.lastname: Jun
authors.forename: S L
authors.initials: SL
authors.lastname: Chung
authors.forename: J C
authors.initials: JC
authors.lastname: Kim
mesh_terms: D000328:Adult; D044466:Asian People; D006085:Graft Survival; D018859:Hair Follicle / Q000637:transplantation*; D006801:Humans; D008297:Male; D013525:Surgical Instruments; D014182:Transplantation, Autologous / Q000295:instrumentation*