title: Alterations in Hair Follicle Morphology and Hair Shaft Production After Follicular Unit Transplantation.
abstract: Follicular unit transplantation is the most commonly performed technique in modern restorative hair transplantation surgery. It relies on the acquisition of intact follicular units from microdissected scalp skin strips and their subsequent transplantation into the recipient regions affected by alopecia. Ideally, the translocation of follicular units from the balding-resistant areas of the scalp (usually the occipital region) to the recipient site should not result in any morphological change in the grafts. Nevertheless, the insults associated with surgical intervention present grafted follicles to mechanical and chemical cues differently from those of the physiological steady-state conditions in undamaged skin. This disruption of the normal follicular microenvironment might alter important aspects of hair biology in grafts, for example, hair cycle and pigmentation, and, in turn, could lead to differences in hair appearance, eventually culminating in a diminished esthetical outcome of the surgery. In this study, the authors analyzed native and grafted scalp hair follicles (HFs) from 2 patients who had undergone follicular unit transplantation surgeries formerly. Scanning electron microscopy and light microscopy-based histomorphometry revealed a marked enlargement of follicular structures in the grafts with a concomitant increase in hair shaft diameter. Immunohistological staining confirmed a thickening of the dermal sheath in transplanted HFs that also harbored a denser vascular network. Taken together, these results show that the grafted HFs analyzed were subjected to marked morphological changes during their residence in the recipient site and that this phenomenon is associated with a modulation of follicular vascularization.
authors: *Zentrum für moderne Haartransplantation, Centre for Modern Hair Transplantation, Berlin, Germany; †Department of Dermatology and Allergy, Charité-University Hospital Berlin, Berlin, Germany; ‡Department of Biotechnology, Technische Universität Berlin, Berlin, Germany; and §Provio GmbH, Biomedical Research and Innovation, Berlin, Germany.
authors: Reza P
authors: RP
authors: Azar
authors: Alexander H
authors: AH
authors: Thomas
authors: Marcus
authors: M
authors: Maurer
authors: Gerd
authors: G
authors: Lindner
mesh_terms: D000328:Adult; D000505:Alopecia / Q000175:diagnosis / Q000473:pathology / Q000601:surgery*; D001706:Biopsy; D005455:Fluorescent Antibody Technique; D018859:Hair Follicle / Q000098:blood supply / Q000254:growth & development / Q000637:transplantation* / Q000648:ultrastructure; D006801:Humans; D008297:Male; D008855:Microscopy, Electron, Scanning; D018919:Neovascularization, Physiologic; D012535:Scalp / Q000098:blood supply / Q000254:growth & development / Q000637:transplantation* / Q000648:ultrastructure; D013997:Time Factors; D014182:Transplantation, Autologous; D016896:Treatment Outcome