In recent years, the FUE procedure—the method of direct extraction of follicular units from different donor zones— has been used with increasing frequency in hair transplantation. This method, despite labor input and high cost, has essential advantages (absence of donor wounds, seam, and post-surgical hems) in comparison with traditional methods of graft harvesting by excision of a skin rag.
During long-term application of this method, sometimes we feel that grafts received by the FUE procedure grow in worse than grafts received in a more traditional way.
Additionally, though the FUE procedure was specially designed in such a way to reduce the transection and damage of follicular units in the process of harvesting them from a donor zone, we raise a question as to whether this method is more traumatic than preparation of grafts from a rag, and could the FUE procedure negatively influence graft survivability?
As we didn't find any data concerning survivability of grafts transplanted by the FUE method in literature, we decided to conduct a double-blind study to answer this question.
Materials and Methods
A patient with a personal history of hair transplant surgery conducted for the purpose of restoration of hair in a zone of scarring received as the consequence of chemical injury was chosen for our study. The scar was in the shape of an oval of 4х3 centimeters in size and was settled down in the parietal area, to the left side.
The case of scarring alopecia was not chosen casually:
First, statistically, FUE procedures more often are used in small-scale surgeries with the purpose of restoration of hair in scars of various origins. Secondly, as we know, growth of hairs from the follicular units implanted into scar tissue have the worst survival rate, and if the results of our observation are positive after all, grafts implanted into intact tissue would certainly grow with even better results.
Excision of a very small rag (0.6 cm in width and 2.5 cm in length) from the middle part of an occipital area was carried out under local anesthesia by one-bladed scalpel. The wound was closed by a double continuous suture.
As a result of rag preparation by means of a stereomicroscope, 107 follicular units were received. From these, 22 were mono grafts, 59 duo grafts, and 12 trio grafts. Thus, the 107 grafts contained 176 hairs were received.
Using cutting instruments with a diameter of 0.95 mm, slightly above the donor wound at a depth of 2-3 mm, cuts were made, after which grafts were obtained by tweezers. 50 grafts were received by extraction. They contained 90 uninjured hairs. Several follicles were transected. Such damaged follicles weren't considered in the calculation.
Thus, 50 grafts obtained by the FUE procedure contained 90 hairs.
After the conduction of block anesthesia, assistants started to create micro-apertures in the area of the scar using Nokor needle No. 18. Thus, 107 micro-apertures were created in the central part and left third of the scar, and 50 were made on the right side. A special strip of 3 mm in width was left between them. This was intended to be filled in at the following surgery.
Follicular units received by preparation of a rag were implanted into 107 micro-apertures in the central and left parts of the scar by jeweler tweezers, and 50 micro apertures in the right third of the scar were filled with grafts received by the FUE procedure.
By the end of the procedure, 176 hairs were transplanted in the left and in the central part of the scar, and 90 hairs in the right part. They were divided by a line of 3 mm of scar tissue, where implantation was not carried out.
The quantity of hairs sprouted to the right and to the left of this strip was calculated three and five months post-surgical. Thus, neither the patient, nor the assistant making calculation, knew how many grafts and what type of grafts were transplanted in a certain part of the scar. Cicatrical processes after receiving of donor material by both methods were also compared.
Results of Research and Discussion
As the calculation of hair in three months time shows, in the central and left part of the scar (to the left of the dividing strip), 150 hairs grew, and in the right part of a scar (to the right of the dividing strip), 75 hairs grew.
Five months after the surgery, the number of the grown hairs increased to 165 and 98, respectively. Calculation of thin and fragile grown hairs wasn’t difficult. It’s highly improbable to miss the transplanted hairs with the hair growing around the scar.
As we would expect, the most intensive growth was noted at the edges of the scar. In the middle of the scar tissue, growth was weaker. Survey of the donor party revealed a scar in the place of the rag excision. In those sites of the donor area, where follicular units were received by the FUE method, a noticeable cicatricial process was not observed.
As the results of our supervision showed, 150 hairs (85 % growth) sprouted out from 176 follicles in grafts received by rag preparation in the first three months after the implantation using the Strip method in cicatricial tissue, and 165 hairs (94 % growth) were evident after five months.
From 90 follicles transplanted using the FUE method, 75 hairs (83 %) grew in three months, and 98 hairs (109 %) grew in five months. This fact can be explained by the following: The damaged follicles in FUE grafts weren't considered at calculation before implantation; however, they regenerated and sprouted.
Many experiments confirm that the cut follicles keep the ability to grow. Thus, the stronger trauma of the follicles is, the slower is their growth until the point of no return, when the scale of damages becomes pernicious for a follicle.
It is significant that in three months after transplantation, growth of Strip and FUE- grafts was almost identical (85% and 83 %), and in five months, the difference was 15% (94% and 109%, respectively). The main reason for this gain, most likely, is the share of the overdue functioning of the cut but still alive follicles in FUE grafts.
At the same time, it is necessary to consider the fact that the central part of a scar where blood supply is always worse as compared to at the edges, was filled with ordinary grafts, received by the Strip method. Naturally, that growth of hair in the center is weaker than on the periphery.
This affected the results of our research, having reduced the percentage of survival of Strip grafts, in comparison with FUE grafts, located in the peripheral part (the right third) of cicatricial tissue. The survival rate of 94% is quite a good figure for grafts implanted into intact tissue, and in our case, transplantation was carried out into a small but cicatricial area.
Thus, based upon the results of our experiment, it is possible to say with confidence that the survival rate of FUE grafts is proportional to the survival rate of Strip grafts. The excision of even a very thin rag (0.5 cm in width) left a linear scar in the donor area, while in sites where grafts were received by the FUE method, any visible changes were not revealed at all.
Based on this evidence, how should we explain the feeling of weak growth of grafts after FUE procedures? Most likely, FUE procedures were used to correct scars or as a finishing (final) stage, after several large-scale hair transplant surgeries. It is a well-known fact that, after repeated surgeries, growth of hair is weaker than at the first surgery, when implantation of grafts happens into intact tissue. Each new intervention leads to the emergence of micro-scars in the recipient zone, which in some degree reduces survival rate of further transplanted grafts.