It is very uncommon that a hair transplant performed by an experience competent doctor will not grow and the yield should be around 90-95% yield of placed grafts regrowing. A Hair Transplant result evolves slowly over 12 to 18 months before full growth should be achieved; technical and medical procedures must be in place to care for the hair on removal, cleaning, slit making and placement.
Are the grafts only being removed from a safe zone, where the hair is immune to the effects of DHT, and male pattern loss; this is easier to predict with the FUT technique compared to FUE as the zone is localised to a smaller area.
Graft transection is the enemy of a good result. Either via FUT or FUE transection is kept to minimum percentage and any transected grafts not placed as the probability of regrowth is minimal.
Miniaturised hairs in the donor area; If the % of miniaturisation in the donor is high it can mean a hair transplant is not advisable due to the trauma of extraction it will likely conclude they will not survive.
The grafts need to be cleaned, this should always be under stereo microscopes to ensure the best quality and care is taken, and then held in the appropriate holding solution until they are ready to be placed in the recipient area.
Creating the recipient sites, depth control, how close the slits are made to each other, too close can impair healing, skin quality and regrowth or yield. Custom-made blades allow for greater control and higher density to be placed, safely.
Follicular unit are delicate and need to be handled with care; holding the graft when being placed is important, if care is not taken too much pressure can be applied and the graft crushed, if placed it will not grow.
The patient also has a responsibility for graft care post operation, washing the grafted area, especially over the first 2 weeks as the scalp is healing and the grafts are bedding into the new area.
Care should be taken not to massage too hard or aggressively, not to knock your head on sharp objects; a graft can be dislodged from the recipient site and if not replaced with speed will not regrow. As a potential patient you need to research thoroughly, try to speak to previous patients, question the doctor as to the clinic protocols and what happens if the yield is not as expected.