Long‐hair follicular unit excision enhances the cosmetic results of hairline restoration: A retrospective study in Chinese recipients

Long‐hair follicular unit excision (LHF) is gaining popularity, especially for hairline restoration, because it helps avoid hair removal in the donor area and provides better immediate postoperative results.


| INTRODUC TI ON
The hairline has a considerable esthetic significance because it frames an individual's facial profile.Hairline transplantation has grown popular for achieving natural-looking hairlines, and the demand for grafts has increased.Transplant surgeons must have sufficient professional knowledge, patience, and precision as well as a good hand-eye coordination. 1mpared with follicular unit transplantation (FUT; the traditional hair transplantation technique), follicular unit excision (FUE)   is more popular due to the hidden dispersion, smaller size of scar dots, and lower postoperative pain. 2 Nevertheless, shaved hair in the donor area and shorter hair in the implant area may become a major confusion for patients with FUE. 3 Therefore, FUE without donor shaving (i.e., long-hair FUE [LHF]) has been developed in recent years.LHF offers the following advantages: (1) the donor areas do not require shaving; (2) postoperative marks in the donor and implant areas are almost imperceptible, even during the shedding of transplanted hair; (3) long hair without shedding lends a natural appearance in the recipient area, allowing patients to resume their normal and social activities without a substantial impact; and (4) surgeons can optimize graft usage during limited graft availability due to visualization of coverage throughout the procedure. 4We aimed to evaluate data from patients who underwent hairline restoration with LHF and perform analyses of the safety and effectiveness.

| Patients
Data from 248 patients (223 women and 25 men) who underwent hairline restoration with LHF between September 2018 and June 2022 were collected.The transplanted area and occipital hair density were assessed preoperatively.No patients had a history of hypertension, heart disease, diabetes, or scarring.The study was performed in accordance with the principles of the Declaration of Helsinki.Written informed consent was obtained from all patients; consent for the use of clinical photographs was obtained from patients whose images were used in the study.LHF was performed using standard measurements and formulas to monitor the outcomes.
After 9 months of follow-up, patient satisfaction and quality of life surveys were conducted, and graft survival was measured.
Patients rated the postoperative satisfaction using a 5-point Likert scale (1, Very poor; 2, Poor; 3, Average; 4, Good; and 5, Very good). 5The survey questions were as follows: (1) "How satisfied are you with the immediate post-operative satisfaction?"and (2) "How satisfied are you with 9 months post-operative satisfaction?"The average scores from this survey represented the satisfaction level.Generic Quality of Life Inventory-74 (GQOLI-74) was used to evaluate the quality of life of the two groups before and after the operation, consisting of 64 items in 4 dimensions.The maximum score for each dimension is 80, and the higher the score, the better the quality of life.

| Preoperative preparation
Alcohol consumption was prohibited for 1 week prior to the surgery.
The day before the surgery, the patients applied a large amount of conditioner after washing their hair; this was important for subsequent extraction, implantation, and anti-tangling.

| Hairline design
Clinicians communicated with each patient preoperatively to understand the patient's hairline requirements.The patient sat facing the mirror, and the hairline was designed using an eyebrow pencil.After obtaining the patient's confirmation, the edge line, midline position, and peak point position were re-marked using a surgical marker to obtain the final design (Figure 1A).

| Donor area: graft incision and extraction
The key aspect of LHF is harvesting intact hair follicles without cutting the hair shaft and preventing the hair shaft from entangling with the punch tip. 6The punch was designed with a groove, and the hair was placed in the groove during extraction while rotating at an angle of <270° to avoid hair breakage (Figure 1B). 4 The ideal graft length is 4-10 cm, which is convenient for extraction and implantation.
The extracted hair follicles were placed in Ringer's lactate solution (pre-chilled on ice); care was taken to avoid drying of the follicles throughout the process (Figure 1C). 7th the patient and physicians placed in the prone and seated positions, respectively, the hair follicles were extracted from the posterior occipital region using an open-window hair extraction drill (Figure 1D).The target hair was placed in the notch of the drill, which was rotated by 180° for extraction.A swelling solution was also injected into the posterior occipital area; as the scalp swelled and the follicle gap widened, the drill was less likely to damage the adjacent follicles during extraction.The assistant held the extraction forceps on one side of the scalp and immediately removed the graft from the surgeon's field of view; this allowed the surgeon to view the donor area and avoid over-extraction.

| Graft separation
Two other assistants observed the grafts under high magnification; carefully removed the epidermis and excess fat tissue around the hair follicles using a blade; sorted the follicles into single, double, coarse, fine, and very fine types; and eliminated curly hairs.They took care to not bend the hair follicle during separation and implantation to prevent damage to the hair bulb and avoid reduction in the postoperative long-hair graft survival rate.They also prevented dehydration of the hair follicle and other medically induced injuries.The isolation time did not exceed 8 h (Figure 1E).During the entire process, the hair follicles were not permitted to dry. 8

| Graft implantation
The patient was placed in the supine position.The surgeon was seated and held the surgical needle and hair implant forceps for the implantation (Figure 1F).When planting the hairline, the traditional way of drilling involves the use of a sapphire hair transplant blade; however, the blade bears a linear hole with a large aperture, which causes greater bleeding.Therefore, it cannot achieve a high planting density.We generally use 0.6-mm surgical needles for implantation; perforation with these induces less trauma and yields circular holes, which are more suited to the hair shape.After implantation, the hair does not fall off easily, especially during follow-up.The hairline is a zone wherein the hair progressively becomes finer and less dense until the bare forehead skin is reached. 9LHF allows surgeons to visualize hair implantation outcomes in real time; thus, they can select implants of suitable diameters and perform real-time adjustments of the hair implantation angle, direction, depth, and density.

| Patient confirmation
After implantation, the patient checked the implanted hairline in a mirror and confirmed whether it was satisfactory.

| Postoperative treatment
The patient took oral antibiotics for 3 days, avoided collisions and pressure in the implant area, and visited the hospital for a hair wash and scab clearing.Ten days later, topical minoxidil was administered to prevent hair loss.

| Data collection and analysis
The following data were recorded: number of patients, sex, intraoperative graft number, density, intraoperative transection rate, and surgery time.Data on complications, graft survival, and patient satisfaction were obtained at follow-up.
Before transplantation, five 1cm 2 areas were randomly marked in the recipient region.The number of follicles in the labeled areas was counted under dermoscopic guidance on the fifth postoperative day (number 5D) and at 1 year (number 1Y) after the surgery.The survival rate was calculated using the following formula: (average of number 1Y/average of number 5D) × 100%.GraphPad Prism 9.0 was used for statistical analysis.
Measurement data were expressed as the mean ± SD and tested by a t-test when they were in line with normal distribution and had equal variance.p-values of <0.05 were considered indicative of a statistically significant difference.

| RE SULTS
All procedures were performed by a team of one surgeon and three assistants.The planned extraction density was set at 15-25 FU/cm 2 .
The mean number of total extracted hair grafts, transection rate in the extraction area, and extraction time were 1970 ± 124 FU, 3.9 ± 0.2%, and 3.2 ± 0.8 h, respectively (Table 1).The hairline implantation density was set at 50-70 FU/cm 2 .The mean number of the total transplanted hair grafts and the implant time were 2031 ± 371 FU and 3.8 ± 1.9 h, respectively (Table 2).Unlike in conventional FUE, the extracted area (Figure 2A) in LHF did not require shaving, and the hair in the implanted area blended better with the natural hair (Figure 2B).The grafts recovered well in the implantation area during the immediate postoperative period; partial graft loss was observed 1-3 months postoperatively.
The hair loss marks in LHF were less obvious and more natural as compared to those in the blank area after shedding in traditional FUE (Figure 2C).Nine months postoperatively, the grafts covered the entire implantation area (survival rate: 93.1 ± 1.3%; Table 2).No folliculitis was observed in the transplanted area, and the posterior occipital area healed well; only five patients experienced mild folliculitis 7 days postoperatively (Table 3).The immediate postoperative patient satisfaction survey revealed that all patients were "very satisfied" with the immediate postoperative results.However, in the 9-month postoperative patient satisfaction survey, 195, 39, 5, and 9 patients graded the outcomes as "Very Good," "Good," "Average," and "Poor," respectively.The mean patient satisfaction scores immediately and 9 months postoperatively were 5 and 4.7, respectively (Table 4).The scores of physical function, psychological function, social function and material life function after operation were higher than those before operation (p < 0.0001) (Table 5).

| Case presentations
A 24-year-old woman with an M-shaped frontotemporal region underwent hairline correction surgery with 2527 LHF grafts (Figure S1).
A 35-year-old woman with an M-shaped frontotemporal region underwent hairline correction surgery with 2163 LHF grafts; she was followed up for 1 year (Figure S2).Transection rate (%) 3.9 ± 0.2 Note: Values in table are presented as the mean ± SD unless stated otherwise.
TA B L E 2 Characteristics of surgery according to implant area.A 41-year-old woman with a high forehead and an M-shaped frontotemporal region underwent hairline correction surgery with 3357 LHF grafts; she was followed up for 4 years (Figure S3).

| DISCUSS ION
The hairline represents an important demarcation of the facial contour that balances the upper third of the facial profile; thus, a well-defined hairline is of great importance to facial esthetics.create a natural appearance.This is beneficial to patients with social concerns, special occupations, and personal needs, among others, who do not wish to have noticeable surgical marks.Thus, LHF allows quick reintegration into social and professional activities following surgery.
In the present study, we investigated data from 248 patients who underwent hairline correction and performed analyses of safety and effectiveness.We found that compared with FUE, LHF did not have a noticeable recovery period and that most patients were very satisfied with the immediate postoperative results and the degree of hair maintenance during the shedding period.The survival rate of grafts with LHF was also higher.LHF grafts are believed to be longer, less thoroughly sterilized, and more prone to postoperative infection.However, a statistical analysis revealed that very few patients developed folliculitis in the donor area 7 days after the surgery; furthermore, the symptoms of folliculitis disappeared after the application of antibiotic ointment, which had no impact on the final outcome of hair transplantation.
The mean patient satisfaction score immediately after the surgery was 5 points; the score remained relatively high at 9 months after the surgery.Thus, LHF can quickly restore the basic facial contour line, improve the forehead and facial proportions, enhance the facial balance and aesthetics, and provide significant clinical results; these can quickly rebuild the patients' confidence and improve their quality of life.
However, LHF also has some disadvantages.It is a time-and energy-consuming procedure, and surgeons are required to have a high reserve of professional knowledge, technical expertise, care, and patience.From the patients' perspective, the high cost of LHF makes it prohibitive; thus, most patients with LHF currently only undergo hairline remodeling or eyebrow and eye hair transplantation. 12derstanding LHF and performing it proficiently can enable surgeons to provide a more suitable surgical alternative to the patients, improve patient satisfaction, and increase competitiveness in the field.

AUTH O R CO NTR I B UTI O N S
M.J. designed the study and analyzed the data.M.J. and Z.J. wrote the manuscript.J.Z., L.P. and Y.D. contributed for collection of clinical data.M.J. and L.P. reviewed and revised the manuscript.L.P. and Y.D. conceived of and supervised the study.All authors have read and approved the final manuscript.

CO N FLI C T O F I NTER E S T S TATEM ENT
All authors have completed and submitted the ICMJE Form for disclosure of potential conflicts of interest and none were reported.

DATA AVA I L A B I L I T Y S TAT E M E N T
The data that support the findings of this study are available from the corresponding author upon reasonable request.

E TH I C S S TATEM ENT
The study was approved by the Institution Review Committee of

F
Surgical procedure of longhair follicular (LHF).(A) Pre-operative hairline design.(B) The punch designed with a groove used in surgery.(C) Newly harvested LHF grafts were placed in lactic acid Ringer's solution (pre-chilled on ice).(D) Teamwork for LHF grafts incision and extraction.Front and side views centered around the surgeon.(E) LHF grafts after careful separation.(F) General implant processes.The surgeons promptly insert surgical needle and subsequently implant LHF grafts through the implant forceps.

TA B L E 1
Characteristics of surgery according to donor area.
figures) who have undergone hair transplantation.While FUE offers several advantages over FUT, the donor area still needs to be shaved in this technique. 8Thus, the large shaved area in the occipital region and the short-trimmed hair in the implantation area often prevent individuals from undergoing this technique owing to potential negative effects on work and social activities.Accordingly, LHF offers the following advantages over FUE and FUT: (1) the donor area does not require shaving; (2) the surgical marks are unnoticeable under the cover of the native hair, and the immediate result is natural; (3) grafts with the right degree of curl and thickness can be selected according to the patient's needs; (4) the hair implantation direction, angle, density, and depth can be adjusted in real time as the final result of hair implantation can be observed visually; and (5) the implanted area blends perfectly with the native hair.Even during the follicle shedding period after transplantation, the remaining hair help Values are presented as the number of subjects.TA B L E 4 5-Point Likert Scale for patients' satisfaction with post-operative results.
Note:Values in table are presented as the mean ± SD unless stated otherwise.
Yanbian University Hospital of China and was in accord with the Helsinki Declaration.Written informed consent was obtained from all patients.Animal experiments were carried out in accordance with the guidelines of the Animal Protection Committee of Yanbian University of China.Note: Values in table are presented as the mean ± SD unless stated otherwise.