Clinical effects of autologous follicular unit extraction transplantation in the treatment of secondary cicatricial alopecia after infections

To explore the clinical effects of autologous follicular unit extraction (FUE) transplantation in the treatment of secondary scarring alopecia caused by infections, and to evaluate its effectiveness.

migration of epithelial cells and interfere with their proliferation.Meanwhile, fibroblasts rapidly increase in number, which can lead to excessive granulation tissue formation and eventually result in scarring.The longer the infection persists, the more severe the scarring becomes.
Infections occurring on the scalp can ultimately cause irreversible damage to the hair follicles, leading to cicatricial alopecia. 7re, we introduce an effective surgical procedure called FUE to treat secondary scarring alopecia caused by infection, and present a series of cases that demonstrate aesthetically pleasing results.

| Participants
A total of nine patients with secondary cicatricial alopecia caused by infection were selected from Chengdu Hengmei Hair Medical Clinic between January 1, 2021, and June 30, 2022.Among them, there were two female patients and seven male patients.The ages ranged from 19 to 59 years, with an average age of 30.9 years.The distribution of alopecia was as follows: one case of frontal and hairline involvement, one case of vertex involvement, three cases of occipital involvement, three cases of temporal involvement, and one case of temporal and occipital involvement.All patients' scars are in a stable phase, with no itching, discomfort, or persistent chronic inflammation in the scarred areas and surrounding scalp.Their medical history spans over 10 years, meeting the requirement of at least 1 year of stable condition before considering surgical intervention.
Preoperative routine physical examinations are performed, including blood routine examination, coagulation function test, electrocardiogram, and four examinations for infectious diseases.The enrolled patients have no severe cardiovascular or cerebrovascular diseases, no systemic autoimmune diseases, and all patients are undergoing hair transplantation surgery for the first time.This study complies with the Helsinki Declaration, and all patients have signed informed consent forms.

| Preoperative assessment
Preoperative assessment of local blood supply is conducted using the "puncture method" as follows: Several puncture points are made at the scar site using a 19-G needle, and the presence of local bleeding is observed.If bleeding occurs, it indicates good local blood supply and allows for the proceeding of autologous hair transplantation.
If no bleeding occurs, it indicates poor local blood supply and renders the procedure unsuitable.

| Surgical technique
Due to the lesser trauma and faster recovery associated with FUE compared to FUT, along with its higher patient acceptance, FUE has been chosen as the preferred method for all hair transplantation procedures.
Take preoperative photos and mark the surgical area (Figure 2A), then verify the specific size of the surgery area to determine the number of follicles needed.The specific procedure is as follows: Cover the balding area with plastic film and draw the outline of the balding area on the film.Place the film on a specialized grid board to count the total area (Figure 2B).Trim the hair in the donor and recipient areas according to the surgeon's needs for easier surgical operation.Take a seated position, disinfect and drape the area, prepare the anesthesia.The anesthesia mixture consists of 15 mL of 2% lidocaine injection, 10 mL of ropivacaine injection, 50 mL of saline solution, and 0.35 mL of 0.1% epinephrine.After the mixture is prepared, perform a circular swelling anesthesia on the occipital area.
Once the anesthesia is successful, inject the swelling solution.The swelling solution consists of 100 mL of saline solution and 0.5 mL of 0.1% epinephrine.The injection of the swelling solution is done subcutaneously and intradermally, until the skin feels tight.The primary objectives of injecting the swelling solution are as follows: (1).To expand the skin, increasing the spacing between hair follicles and minimizing potential damage.(2).To safeguard major blood vessels and minimize bleeding.Next, take a prone position and utilize a 1.0 mm diameter electronic punch device (manufactured by Xi'an Xingmao Co., Ltd.) to extract the grafts from the donor area.Once extracted, the grafts are divided and placed in a multi-saline solution at 0°C for preservation.It is not necessary to be overly meticulous in the tissue division process during transplantation, as sufficient surrounding tissue can prevent dehydration and necrosis, providing the necessary nutritional support for the graft and improving posttransplant survival rates.After disinfecting and draping the recipient area, the aforementioned anesthetic solution is used for circumferential anesthesia, followed by swelling with adrenaline-free saline solution.Then, a gem knife with a diameter of 1.0-1.2mm is used to create incisions in the surgical area following the direction of the hair follicles.Carefully implanting the grafts into these incisions using implantation forceps.To aid in the recovery process, the donor area, from which the grafts were extracted, is covered with a dressing soaked in a solution called Kangfuxinye.Finally, sterile gauze bandages are applied with pressure to the donor area (as depicted in Figure 2C).b.The rate of complications, encompassing infections, skin necrosis, pronounced hematoma, unnatural appearance, and temporary hair loss, is calculated as the number of occurrences divided by the total number of cases, multiplied by 100%.

| Statistical methods
All statistical analyses were performed using Free Statistics software versions 1.8.A 2-sided p < 0.05 was considered statistically significant.

| RE SULTS
A total of nine patients, including seven males and two females, with a mean age of 30.9 years (range 19 to 59 years), underwent a reevaluation 12 months after a single surgical session (Table 1).The average affected balding area was 23.33 cm 2 (range 3-54 cm 2 ), with an average of 835 FUs (range 150-1907 FUs) transplanted resulting in aesthetically acceptable scar camouflage posttransplantation.All patients underwent only one surgery, with an average duration of 2.12 h (range 1.17-4.17h).During the follow-up, six out of the nine patients expressed utmost satisfaction with the surgical outcome, two were satisfied, and one expressed dissatisfaction, resulting in a satisfaction rate of 88.9% (Figure 1).
We documented postoperative complications such as infection, skin necrosis, significant hematoma, unnatural appearance, and temporary hair loss.Among these nine cases, only one experienced an infection, resulting in a complication rate of 11.1%.
Case 1, a 42-year-old married male, had a localized skin infection in the occipital area over 10 years ago, which resulted in a patch of hair loss measuring approximately 42 square centimeters after healing.The surgery used the FUE technique to extract a total of 1529 FUs, which were evenly transplanted to the balding area and appropriately blended with the surrounding hair for a natural transition.
The surgery lasted for 2.8 h, and pre-and postoperative follow-up photos are shown in Figure 2. The graft survival rate was approximately 80%, and the patient rated his satisfaction level as 4 (very satisfied).

| DISCUSS ION
There are various factors that can lead to secondary cicatricial alopecia, such as burns, surgeries, infections, tumors, and more.Our research specifically focuses on the secondary cicatricial alopecia caused by infections.Specific factors of infection include bacterial infections, such as those caused by Staphylococcus aureus, which can lead to conditions like furuncles, abscesses, and cellulitis that may result in cicatricial alopecia.Additionally, fungal infections like tinea capitis, viral infections such as HIV, protozoan infections, and even spirochete infections can contribute to the development of cicatricial alopecia.The cases described in this article primarily focus on localized inflammatory skin infections caused by bacteria and fungi, leading to scar formation and hair follicle destruction, eventually resulting in cicatricial alopecia.
Currently, the main approach to treating secondary cicatricial alopecia is through surgical procedures, including scalp reduction, flap repair, tissue expansion, and hair transplantation.Among these, autologous hair transplantation is considered a safe and effective TA B L E 1 Patient characteristics and treatment details.This is especially important for areas such as the hairline, eyebrows, beard, and temples, where patients have higher demands for aesthetic results, and require more attention to detail.

Case
The survival rate of transplanted hair in cases of cicatricial alopecia is relatively lower compared to normal skin, making it crucial to focus on strategies that enhance survival rate during the surgical procedure.In addition to the aforementioned judicious distribution of graft density, attention should also be paid to routine intraoperative procedures, which aim to maximize the vitality of the hair follicles.These may include measures like maintaining a lowered temperature, ensuring hydration, and minimizing mechanical trauma.
Postoperatively, the addition of minoxidil can help decrease hair loss, and improve overall treatment outcomes.It is recommended to initiate minoxidil usage based on the condition of the skin approximately 15 days after the surgery.Additionally, the combination of autologous platelet-rich plasma (PRP) can be used to improve blood supply in the scarred area, which can be injected before or during the surgery.Preoperative injections provide favorable nutritional conditions for hair transplantation, 11 while intraoperative injections can reduce graft damage, accelerate wound healing, and activate dormant hair follicles. 12 this study, we conducted research on nine patients and obtained promising results.However, it is important to acknowledge certain limitations of this research.Firstly, it was a retrospective case analysis without a control group.Additionally, the sample size was relatively small.Consequently, future investigations will encompass larger sample sizes to validate these findings.Furthermore, we will conduct further research among patients with secondary cicatricial alopecia caused by other factors, in order to gain deeper insights.

| CON CLUS ION
We utilized the FUE technique to treat secondary cicatricial alopecia resulting from infections with good blood supply, and achieved favorable outcomes.This method is minimally invasive, with a low incidence of complications, and high patient satisfaction post-surgery.
It is an effective approach that aligns with the current trend of "minimally invasive" characteristics in cosmetic surgery.
a. Subjective satisfaction rating of the patient's outcome 12 months later, with a rating scale of 4 = Very satisfied, 3 = Satisfied, 2 = Not very satisfied, 1 = Not satisfied.Satisfaction rate is calculated as the number of satisfied cases divided by the total number of cases, multiplied by 100%.

F I G U R E 1
Satisfaction of the patients with scarring alopecia.4 = Very satisfied, 3 = satisfied, 2 = not very satisfied, 1 = not satisfied.66.7% of the patients felt very satisfied, 22.2% said they were satisfied, and 11.1% said they were dissatisfied.F I G U R E 2A 42-year-old male patient had scarring alopecia on his occipital region.In total, 1529 FUs were extracted and transplanted by the follicular unit extraction transplantation.(A) The preoperative design for occipital scalp cicatricial alopecia.(B) The balding area of the patient in the image measures 42 square centimeters.(C) Immediately After hair transplantation.(D) 6 months after the treatment.(E) 15 months after the treatment.surgical method.Autologous hair transplantation involves extracting hair follicles from the patient's own dominant donor area at the occipital region, preparing them through division, and then transplanting them to the desired area in accordance with the natural hair growth direction.Once the hair follicles successfully survive, they will grow into healthy new hair, thereby improving the local hair density, and achieving aesthetically pleasing results.There are two classic methods for extracting hair follicles in autologous hair transplantation: FUT and Follicular Unit Extraction (FUE).FUT involves harvesting a long elliptical strip of scalp from the donor area to prepare the follicles, resulting in a linear scar in the donor region post-surgery.In contrast, FUE employs a 0.8-1.2mm electronic punch device to individually remove follicular units directly from the donor area and then prepare them for transplantation to the recipient area.This technique minimizes damage, facilitates faster wound healing, and leaves nearly invisible scars in the donor area, making it more readily acceptable to patients.However, FUE also has certain limitations such as extended surgical time and the risk of significant follicle loss if not performed appropriately.Our research findings indicate that among the nine patients included, the satisfaction rate after 1 year of surgery was 88.9%.Only one case experienced postoperative infection, resulting in insufficient hair density, and low patient satisfaction.This confirms that FUE technique is an effective approach for treating secondary cicatricial alopecia caused by infection, with high patient satisfaction and low incidence of complications.During the surgical procedure, it is essential to control the dosage of adrenaline to preserve blood supply to the donor area, and prevent vasoconstriction-induced local skin ischemia and necrosis.Our approach involves adding a small amount of adrenaline, typically at a concentration of 1:200000, during the administration of local anesthesia around the scar area.In the central region, normal saline is used for subcutaneous or intradermal injections to appropriately thicken the scalp and minimize trauma.For patients experiencing significant intraoperative bleeding, compression techniques can be employed for hemostasis.It is worth noting that none of the nine cases in this study experienced skin necrosis.In the context of hair transplantation surgery for scar-related hair loss, determining the appropriate number of grafts per square centimeter is crucial.Both doctors and patients aim to achieve aesthetic results in a single procedure.However, scar tissue is rigid and has limited blood supply.Blindly implanting grafts at a high density may lead to lower postoperative survival rates and potential complications, such as infection and skin necrosis.Typically, in areas with good scar elasticity and abundant subcutaneous fat content, a recommended planting density is 30-40 FU/cm 2 .In areas with poor scar elasticity and less subcutaneous fat content, a recommended planting density is 20-30 FU/cm 2 .For scars after skin grafting, a density of 10-15 FU/cm 2 is suggested.For patients with poor results from the needle puncture test results, such as in adhesive scars, a prior fat transplantation can be performed to increase local skin thickness, enhance local blood supply, and improve the local microenvironment before proceeding with hair transplantation.Studies have shown that fat grafts can release a substantial amount of vascular endothelial growth factor, inducing blood vessel formation and collagen deposition, thus softening scar tissue.In cases of hypertrophic and keloid scars with evident tissue hardening and poor blood supply, alternative treatment methods are recommended.[8][9][10]For extensive scar alopecia where the donor area for autologous hair transplantation is limited and cannot meet postoperative aesthetic demands, alternative surgical approaches or a combination of surgical techniques, such as scar excision and tissue expansion with skin, may be necessary to achieve improvement.Additionally, the aesthetic outcome of the transplanted area post-surgery is not only related to hair density but also to the direction, angle, and layering of the transplanted hair in the recipient area.