الفهرس 
Hair Follicle ,Density and directionsOnly 14 pages are availabe for public view
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Abstract
Hair transplantation has been popular as a permanent method for
restoring hair loss especially in camouflaging of scarring alopecia by providing
restoration not obtainable with other methods like expander or
micropigmentation (Barr and Barrera, 2011b).
Follicular unit extraction is a new method of hair restoration surgery
being firstly introduced by Rassman and Bernstein at 2002 as a better method
regarding low scar tissue than FUT technique but in FUE technique the person
must have a good donor area specially in large surface area (Harris, 2013, Yoo
et al., 2019).
Hair restoration surgery in scars is a challenging procedure due to low
vascularity and high tissue stiffness that in turn provide a low survival rate of
transplanted grafts (Saxena et al., 2016)
Full scar history including size, type of healing, healing duration and
complications of wound are a very important details which will give a predicted
result and survival rate of hair grafts.
The timing of hair restoration surgery is important, the scar should be
fully mature (pale and soft) and not complicated.pink scars are still immature
and morevlikely to bleed during procedure.the golden waiting period for hair
transplantation is 4-6 months and the scar should be stable (Barr and Barrera,
2011b).
The cause of scarring alopecia is important for result prediction, scarring
alopecia due to burn give a better results than that is due to wounds.
Complicated wounds will give bad results than non-complicated wounds.
Sufficient subcutaneous tissue is important for follicular unit transplantation.
Graft survival rate of hair restoration surgery can range from 0 upto 95%
in scar tissue (Farjo et al., 2015)
Summary
125
Extensive form, complicated scarred tissue and atrophic scars give
unsatisfactory results in hair restoration surgery (Ağaoğlu et al., 1999).
In most of studies about hair transplantation in scars, the graft was taken
from the donor site and implanted in the scarred recipient area without any
treatment of the recipient area before hair transplantation.
It is known that cicatricial recipient areas do not provide an optimal
environment for hair transplant due to tissue stiffness, decreased vascularity and
limited underlying subcutaneous tissue, which influence hair graft take and
survival. To enhance the graft take and survival rate of implanted follicular
units.
Many factors can denote the aesthetic outcome of hair restoration surgery
in scars.however the most important two factors are availability of donor site
(specially in large alopecic surface area) and the quality of recipient scarred
tissue.the first factor is constant and can‘t be changed the other factor can be
modulated.mature scar with sufficient subcutaneous tissue enhances the graft
survival.scarrd tissue can be improved dramatically with microneedling and
PRP injection before hair transplantation as a preparation for the recipient scar.
Most of done studies worked on the recipient area maybe by microfat
grafting, increasing the subcutaneous tissue by dermofat grafting and improving
skin quality by CO2 laser.
In the current study we used platelet rich plasma 3-5 sessions before hair
transplantation and last session was before hair restoration surgery by 5-7 days.
Platelet-rich plasma (PRP) is a concentrated form of plasma which
contain platelets seven times the amount in normal plasma. Because the
underlying disease process in cicatricial alopecia is inflammatory, PRP is a
treatment option due to the various growth factors it contains, such as PDGF
Summary
126
(platelet-derived growth factor) and VEGF(vascular endothelial growth factor),
that influence wound healing, tissue repair, and remodelling of scar tissue.
Improvement of the scarred tissue was noticed after microneedling and
PRP injection by clinical examination and digital microscope used in the current
study.
The cause of cicatritial alopecia is an important factor for result
prediction as the following; postburn scars showed better results and better graft
survival rates than traumatic and incisional scars due to deeper scarring damage
to subcutaneous tissue (Jung et al., 2013a)
Hair transplantation, after micro-needling and PRP injection, is a
promising treatment for post burn alopecia. However, further studies with larger
series and a comparative study comparing solo hair transplant on post burn scar
and hair transplant after micro-needling and PRP injection are required.