Follicular Unit Transplantation (FUT) Technique
Hair Transplant earliest technique is Follicular Unit Transplant Technique also called the Strip Method. In the strip method of hair transplant a strip of scalp bearing hairs of appropriate density is excised using either a single No. 11 or No. 15 blade. The blade is inserted at an angle to the scalp which parallels the angle of the hair follicles into the scalp to avoid any damage to the hair follicle roots. The use of tumescent solution for infiltration also minimizes the follicle transection by appropriately aligning the hair follicles and providing a plane between the hair follicle bed base and the larger nerve plexuses and vessels that lie within the deep subcutaneous tissue.
Hair Transplant by strip method, the width of the strip is determined by the laxity of the patient’s scalp in order to yield the maximum number of grafts while limiting the tension on closing the edges. The edges are closed in layers with the deeper layers closed using absorbable sutures (vicrly) and the outer layer with non-absorbable sutures (ethilon/prolene).
Hair Transplant Advantages by strip technique are: larger number of hair follicle units harvested in a shorter period, lower rates of hair follicle transection and the ability to include the protective surrounding tissue containing the stem cell. Another advantage of FUT technique is that the remaining scalp is left undisturbed and can be used for repeat harvesting of the hair follicles using either FUT method or the follicular unit extraction (FUE) method.
Hair Transplant by FUT technique has one important and bothersome disadvantage which is the resultant scar over the donor area which becomes visible when hairs are kept short. There are various Plastic Surgery techniques with which the resultant hair transplant scar can rendered almost invisible. Ask your surgeon about the technique he is going to employ to prevent the scar at the donor site during and after hair transplant.
Hair Transplant by FUT: Separation of the hair follicles
After harvesting the grafts, the hair follicle units obtained are dissected under microscopic visualization. Dissection under magnification is specially important to prevent follicle transection in this hair transplant technique.
In FUT Technique, hair follicles are separated into clusters of 1-4 hairs are transplanted. On an average a single naturally occurring hair follicle unit contains about 2.3 hair follicles.
The final separated hair follicle ready for hair transplant should have a pear shape where in the epidermis has been maximally trimmed and the dermal and subcutaneous tissue surrounding the follicle isthmus and bulb remains intact.
This optimal hair follicle shape is frequently achieved after FUT Technique, but infrequently from follicular unit extraction technique or robotic hair transplantation. The cushioning provided by these surrounding tissues has been found to maximize the hair follicle viability by minimizing desiccation during pre-insertion storage and mechanical trauma to the follicle from handling during hair transplant surgery.
Selection of proper storage solution has grown increasingly more important as “mega-session” hair transplantation involving slimmer grafts have become more common and out-of-body time has increased. Survival of transplanted grafts has been shown to decrease by about 1% per hour out of the body time. Factors which reduce the graft survival during this extended out-of-body time include ischemia-induced hypoxemia and subsequent adenosine triphosphate depletion, as well as ischemia-reperfusion injury. Three types of storage media (intravenous fluids, culture media and hypothermic tissue–holding solutions) help minimise out-of-body variations in pH, osmotic balance, antioxidant capabilities, and nutrient support to the follicles.
Preparing the recipient area
Various techniques are used to create and prepare the recipient area for transplantation of hair follicles. The critical element with donor area preparation is the angle and direction at which the hair follicles will leave the scalp leading to least damage to existing hairs and the creation of natural appearance of transplanted hair.
The most widely accepted density of hair follicle insertion at the recipient site is 30 hair follicular units per square centimeter. Some of the practitioners advocate for a denser packing of more than 40 follicular units per square centimeter. This can however compromise the viability of the grafts as the competition between the transplanted hair follicles for a limited blood supply increases.
Various techniques are used for recipient site creation and graft insertion. Blades may be cut to match the size of the follicular units to be inserted. Some use hypodermic needles to make incisions for hair follicle placement. Recipient site size increases as the surgeon moves posterior away from the hairline and the priority shifts from single, fine hairs to multiple, coarser hair follicular units.
A “stick-and-place” technique can be used to eliminate the time between which the recipient site is prepared and the hair follicle graft is placed within it.
A “spread-and-place” technique reduces the mechanical trauma from hair follicle graft handling as the hair follicle is placed into a smaller recipient site.
Hair Transplant Intraoperative Steps
- During Hair Transplant the patient is seated in a semi-recumbent position or prone position with head supported.
- Preparation of the donor and recipient area is done with betadine solution and draping is done keeping all asceptic precautions.
- Local anaesthetic is then injected. The donor area is injected superficially first, followed by a slightly deep injection along the entire hairline to create a field anaesthesia. Approximately 25 mL of 1:50,000 adrenaline solution is injected into the donor region for tumescence.
- Wait for 15 to 20 minutes for the tumescent solution to act
- The donor strip is then excised in a superficial subcutaneous plane to avoid trauma to the neurovascular bundle and other smaller vessels.
- The donor-site incision is then closed in two layers with an absorbable suture for deeper layer and 3-0 Prolene suture for the outer layer.
- Hair Transplant team is then split into two.
- Number One Hair Transplant team consists of those who perform the slivering (sectioning of the donor strip into many narrow strips).
- Number Two Hair Transplant team divides these narrow strips to harvest single hair follicles from them.
- Excess tissue is excised to allow the transplantation of just these follicular units.
- Graft cutting is performed with the help of binocular microscopes or microsurgical loupes for accurate dissection.
- This process of follicle seperation is very demanding and time consuming but critical for the successful hair transplant procedure.
- The grafts are cut on a Teflon cutting block by using size-11 /15 scalpel blades or double-sided razor blades.
- While awaiting transplantation, the grafts are stored in cold preservative-free solution of isotonic saline or some other storage solution including dipping the hair roots in PRP solution which some centers claim to be Bio-FUE or some other fancy names.
- While the grafts undergo dissection, the surgeon prepares the recipient sites. This can be done by customised blades or needles depending upon the surgeon’s choice. The recipient sites are made of appropriate size and direction while avoiding transection of existing hair follicles.
- The harvested hair follicles are then inserted into the prepared recipient sites. This is an extremely challenging process and utmost care should be taken to prevent any trauma to the hair follicles.
- Before finishing the procedure the surgeon once again inspects the whole recipient area and if few follicles are found popping out then they are again put inside.
- Hair Transplant procedure should never be done in the hurry to finish the procedure. There should be no hurry to finish the procedure early as final outcome of the patient depends on how diligently hair transplantation is done on that very day.
For insertion of hair follicle Jeweler’s forceps or similar non-toothed forceps are used to gently place the grafts into the recipient sites. Transplanted hair follicle viability is maximized by minimizing the mechanical trauma to the follicle during its insertion. This is accomplished by handling the dead portion of the hair (the part of hair which lies outside the scalp) rather than the sub-epidermal portion of the hair follicle itself. Some hair implantation devices allow for near-simultaneous recipient site creation and hair follicle insertion.