Follicular unit extraction megasession treatment of high‐grade androgenetic alopecia in Asians: Introducing novel principles for surgical design

Male androgenetic alopecia (MAGA) has been one of the most common reasons for hair consultation, which affects more than half of men under the age of 50. Recently, follicular unit extraction (FUE) megasession has been an attractive treatment option for patients with severe AGA. However, compared with hair transplant surgery by traditional FUE or follicular unit transplantation (FUT), a megasession lacks a suitable surgical design solution for Asian high‐grade AGA patients. Therefore, we introduced novel principles for surgical design into FUE megasession for Asians.

Male androgenetic alopecia (MAGA) has been one of the most common reasons for hair consultation, which affects more than half of men under the age of 50. 1,2Miniaturization of hair follicles in the frontal and parietal scalp regions is one of the main features of AGA. 3 Thinning hair is often associated with aging and an unattractive appearance.Besides, patients with AGA may also have psychological problems that could seriously decrease quality of life. 4ir transplant surgery is one of the important treatments for androgenic alopecia. 5,6Recently, a systematic review revealed 85% to 93% graft survival and 90% to 97% patient satisfaction after AGA hair transplantation in MAGA. 7In high-grade AGA, involving baldness on the frontal and parietal areas of the scalp, it is common to transplant a large number of grafts in one session. 8For one-time hair surgery with greater 3000 grafts, follicular unit extraction (FUE) megasession is an attractive treatment option for patients with severe AGA.FUE megasession has been shown to reduce the frequency of surgery and increase hair density with high graft survival. 9wever, compared with hair transplant surgery by traditional FUE or follicular unit transplantation (FUT), a megasession lacks a suitable surgical design solution for Asian high-grade AGA patients.
Therefore, we introduced novel principles for surgical design into FUE megasession for Asians.The purpose of our study was to investigate the naturalness of hair, patient and doctor satisfaction level, and safety assessment of FUE megasession with the specific surgical design, to explore a novel technique for an efficient, satisfactory, and safe FUE megasession procedure.

| Patients
Thirty-six male patients with AGA were enrolled in the retrospec-

| Surgical design
The patient's area of hair loss was assessed and designed preoperatively.The hairline was essential to the naturalness of the hair, and 1-hair thin units were placed in the frontal hairline zone to create a wavy hairline.1-hair thick units were implanted in the vertex transition zone and frontal hairline transition zone (1 cm wide area behind the frontal hairline zone).To make hair appear denser, central forelock zone was filled in with 2-hair units and 3-hair units.Besides, 2-hair units were placed in the area around central forelock zone (Figure 1).
After evaluating and designing the area of hair loss for the patient, we would calculate the number of hair follicles needed for the hair transplant.Then we needed to measure the area and density of the donor area and estimate the total number of hairs in the donor area.The maximum number could be extracted in one session based on 30% of the number of hairs in the donor area.Before the surgery, we made sure that the number of follicles that could be extracted from the donor area was larger than those needed for the hair loss area.

| Acquisition and storage of follicular units
The acquired follicular units were trimmed under 3x magnification to remove excess epidermal tissue and fatty tissue around the follicular units (Figure 2).Follicular grafts were divided into 1-hair thin units, 1-hair thick units, 2-hair units, and 3-hair units (Figure 3).Then, the hair units were placed sequentially in the disposable divided surgical kidney dish.As marked by the curve in the picture, they are sorted and placed in the corresponding areas of the disposable divided surgical kidney dish.Besides, there is spare location for hair units (Figure 4).The prepared follicular units were temporarily stored in Ringer's solution at 4-10°C.To maintain low temperatures, the compact reusable ice pack is covered with waterproof sterile drapes, and the disposable divided surgical kidney dish with Ringer's solution is put upon the flat surface of the ice pack (Figures 2B and 5).This method will keep the grafts at 4-10 degrees Celsius for up to 2 h.The natural density and appearance in one operation.Due to its remarkable effect, high satisfaction level, and few postoperative complications, FUE megasession with the introduced surgical design has great potential for Asian high-grade AGA patients.ice pack is replaced with a new one every 2 h, so hair grafts can be kept cooling throughout the hair transplant procedure.

| Insertion of follicular units
During the graft insertion procedure, the assistant passed the correctly prepared hair units from the disposable divided surgical kidney dish or stainless steel kidney dish to the operator.The operator performed the graft implantation with the stick and place technique (Figure 6).The distribution of implanted hair follicles was consistent with the surgical design.The direction of the implanted hair units could refer to that of the remaining hairs in the recipient area or the normal direction of hairs in the healthy scalp.

| General conditions
Baseline information on patients was recorded after enrollment, including number of patients participating in the trial, Norwood grade, age, course of disease, and family history.
F I G U R E 1 Hair design for advanced hair loss patterns.The hair pattern design is suitable for patients with alopecia in Hamilton Grade V-VI.The hairline is essential to the naturalness of the hair, and 1-hair thin units are placed in the frontal hairline zone to create a wavy hairline.1-hair thick units are implanted in the vertex transition zone and frontal hairline transition zone (1 cm wide area behind the frontal hairline zone).To make hair appear denser, central forelock zone is filled in with 2-hair units and 3-hair units.Besides, 2-hair units are placed in the area around central forelock zone.

| General information about hair transplantation
The general information about hair transplantation was recorded during the operation.Specific data on graft amount, recipient density, and total operation time were collected separately.To make the evaluation more objective, the doctor involved in the satisfaction assessment was not involved in the procedure of patients.

| Safety evaluation
Donor area and recipient area were assessed for any complications.Adverse reactions such as infection, folliculitis, edema, scalp itching, and scar were observed and recorded at any time in the research.

| Statistical methods
All statistical data were analyzed with SPSS 25.0 software, and quantitative data were represented as mean ± SD.

F I G U R E 4
The method of placing hair units into the disposable divided surgical kidney dish.(A) A disposable divided surgical kidney dish with multiple grids at the bottom.(B) Hair grafts are separated into 1-hair thin units, 1-hair thick units, 2-hair units, and 3-hair units.As marked by the curve in the picture, they are sorted and placed in the corresponding areas of the disposable divided surgical kidney dish.Besides, there is spare location for hair units.

F I G U R E 5 A compact reusable ice pack.
F I G U R E 6 Graft insertion procedure.According to the needs of the patient's surgery, the assistant passes the correctly prepared hair units from the disposable divided surgical kidney dish to the operator in a convenient manner.Besides, the operator can focus on the graft insertion process with the stick and place technique and avoid excessive body movements.

| General conditions
A total of 36 male patients with androgenic alopecia were involved in the study.Before surgery, 19 patients suffered from AGA in Hamilton Grade V, and 17 patients suffered from AGA in Hamilton Grade VI.The average age of them was 36.8 ± 9.6 years, and average duration of disease was 8.3 ± 3.8 years.All patients got a positive family history of androgenic alopecia (Table 1).

| General surgical information
During hair transplant surgery, the average graft amount required in the operation was 3705 ± 383 FUs, and recipient density ranged from 30 FUs/cm 2 to 50 FUs/cm 2 .Besides, the total operation time was 10.6 ± 0.9 h (Table 2).

| Satisfaction evaluation results
For patients, most of the patients in the experiment thought the results of surgery were natural, and the average Likert score was up to 4.72.Among them, 30 patients were very satisfied with naturalness of hair, 2 patients were satisfied, and 4 patients gave a moderate rating.Besides, the majority of patients were satisfied with the whole procedure of hair transplant surgery, and the average Likert score was up to 4.64.Among them, 29 patients were very satisfied, 1 patient was satisfied, and 6 patients gave a moderate rating (Figure 7; Table 3).
For the doctor involved in the evaluation, most patients got natural surgical results, and the average Likert score was up to 4.61.After surgery, the doctor was very satisfied with the naturalness of the hair of 26 patients, satisfied with that of 6 patients, and neutral with that of 4 patients.Besides, the doctor was satisfied with the whole procedure of hair transplant surgery for majority of patients, and the average Likert score was up to 4.75.Among them, the doctors were very satisfied with the surgery on 28 patients, satisfied on 7 patients, and neutral on 1 patient (Figure 8; Table 4).

| Comparison of adverse reactions
As shown in Table 5, one of 36 patients developed scalp itching, three of 36 patients developed folliculitis, and one of 36 patients developed edema.Besides, no serious side effects occurred after surgery.

| Case 1
A 49-year-old AGA patient with Norwood-Hamilton stage V underwent FUE megasession treatment with the novel surgical design introduced above (Figure 9).A total of 4367 hair units were placed (1350 1-hair units, 2700 2-hair units, and 317 3-hair units).

| Case 3
A 23-year-old AGA patient with Norwood-Hamilton stage VI had received scalp medical tattooing (SMT) once.After 3 months of SMT, he underwent FUE megasession treatment with the novel surgical design introduced above (Figure 11).A total of 4284 hair units were placed (1100 1-hair units, 2550 2-hair units, and 634 3-hair units).

| DISCUSS ION
Androgenic alopecia patients are prone to anxiety, inferiority, and other psychological problems.Androgenic alopecia may affect the patients' social and interpersonal relationships and cause a huge burden on their life and psychology. 10At present, common treatment options for AGA include medications, hair transplantation, microneedling, low-level laser therapy and injection of platelet-rich plasma et al. [11][12][13] There are two main surgical methods: FUT and FUE.Compared with strip harvesting FUT, there are no linear scars TA B L E 1 General condition of the patients.

Characteristics Values
Cases TA B L E 2 General information about hair transplant surgery.

Characteristics Values
Graft amount (FUs) (mean ± SD) 3705 ± 383 Recipient density (FUs/cm 2 ), range 30-50 Total operation time (h) (mean ± SD) 10.6 ± 0.9 and surgical incision sutures in FUE operation.FUE has become most commonly used donor harvesting technique in clinical application. 12megasession was refined as transplanting over 1000 hair grafts in one time in 1995. 14Over the past years, the number of grafts in one session has continued to increase, as the technique of hair transplant surgery advanced.In 2013, a megasession via strip method was described as transplanting over 3000 grafts in one procedure. 8Recently, the concept of "FUE megasession" was reported to transplant outnumber 3000 grafts in one FUE operation. 9 addition to treating most large area at once, a megasession has been shown to reduce overall downtime, decrease scarring, lessen vascular trauma, and increase hair density. 8A megasession procedure provides enough hair grafts for a more natural-appearing result.However, lack of surgical design solution in a megasession for Asians will confuse young surgeon and bring poor surgical outcomes for patients.The patient's unnatural surgical results may reduce his satisfaction, which will lead to less trust in the surgeon.Medical staff can also be more fatigued over longer surgical periods, resulting in inefficiencies.Therefore, how to perform the surgical design is one of the hot spots of a megasession for Asians.When male patients with high-grade AGA consult a hair doctor, there are large areas of hair loss in their scalps.It is unlikely to fill in the entire affected areas. 15Therefore, the hair pattern design for high-grade hair loss in Asians is especially important.
The main surgical goal for male patients with extensive alopecia is to contour the faces and achieve a natural-appearing result.
Compared with the vertex area, restoration of the frontal and midscalp areas is more prioritized in these people. 15The best way of achieving this is to create a density gradient, in which the density of the front-central area is emphasized, while the hair density on both sides and back of the central forelock areas gradually decreases. 15Therefore, in some patients with relatively insufficient donor areas, we will extract some hair grafts from the upper parietal region moderately.These hair grafts are transplanted to the posterior edge and both sides of hair loss areas.In this way, more transplanted hair grafts can be obtained, making hairs in the hair loss area denser.At the same time, the hair density on both sides of the central forelock areas can be reduced moderately, which prevents the hair density on both sides from being higher than that in the middle.However, patients need to be informed of the risk of loss of hairs acquired in the upper parietal region in the future, and patient's consent needs to be required.Moreover, postoperative patients should adhere to medications such as minoxidil and finasteride to slow down the progression of hair loss and promote hair growth.To simulate a hair density gradient in a normal scalp, surgeons could separate and selectively place 1-hair units, 2-hair units, and 3-hair units. 16In Asian populations, hair diameter tends to taper beyond the central occipital area toward the temples. 17erefore, 1-hair thin units were obtained from the area near the temples, and 1-hair thin units were acquired from the area near the mid-occiput.The anterior portion of the hairline region consists mainly of 1-hair units, and thin 1-hair units may be more suitable to place at the most anterior portion of hairline. 16,18In our surgical design, we placed 1-hair thin units in the frontal hairline zone for the naturalness of the hairline.Behind the frontal hairline zone, 1-hair thick units were implanted in the frontal hairline transition zone and vertex transition zone for the transition of hair density.
The central forelock zone was filled in with 2-hair units and 3hair units to create a higher hair density in the front-central area.
Moreover, 2-hair units were placed in the area around the central forelock zone for a moderate hair density.

TA B L E 5
Adverse events after FUE megasession treatment.

Complications Values
Scalp itching 1 To better accommodate this surgical design option for Asians (Figure 1), we have also introduced the disposable divided surgical kidney dish.The design of the disposable divided surgical kidney dish conforms to the composition of human hair.A study showed that among Asian men with androgenic alopecia, 2-hair units were dominant in the occipital area (donor area). 19Therefore, the disposable divided surgical kidney dish is designed to contain the largest number of grids for 2-hair units.The multiple grids at the bottom of the disposable divided surgical kidney, allows the hair grafts to be submerged in solution, less prone to dehydration.The capacity of this device is large enough to hold more than 2000 hair grafts, and only two dishes are required for one FUE megasession.Besides, hair units are organized into groups with 100 hair follicles in each grid, thereby increasing the efficiency of graft placement and fetching.
Different types of hair units (1-hair thin units, 1-hair thick units, 2hair units, and 3-hair units) are placed in an orderly manner, which can bring convenience to the operators and assistants in the surgery.
Therefore, the disposable divided surgical kidney dish could improve work efficiency, and it is perfect for this type of surgery.
The use of the trumpet punches during the procedure allowed for increased hair yield. 20At the same time, the hair grafts were protected by more fat and tissue around them, and the follicle transection rate was low and no more than 1% in our surgeries.
In the study, FUE megasession with the novel surgical design was satisfactory to most patients.FUE megasession with the novel design method not only treats large areas with a relatively natural density and appearance in one operation but also has few postoperative complications.Moreover, the cooperation and technology among the surgical team members are also critical to the outcome of the surgery.Before starting to attempt FUE megasession, physicians and staff need to go through long-term technical training and experience accumulation.
After surgery, some patients cared about hair loss on the unoperated vertex area of the head, especially young patients.We recommended that these patients continue with minoxidil and finasteride medications.5% minoxidil is applied to the area of hair loss on the top of the head twice daily.Finasteride is given orally at 1 mg per day.
In addition, there are some limitations to this study.The above research is a retrospective, single-center clinical study.The sample size in this study was small, and the ethnicity was relatively homogeneous.More clinical research are needed to further examine other indicators that may be related to the novel surgical design, such as hair follicle survival rate, hair growth status, and long-term complications.Different ethnic groups and research centers need to be added to the relevant research.

| CON CLUS ION
According to the outcomes of our research, FUE megasession with the introduced surgical design is a satisfactory treatment option for patients with high-grade AGA in Asians, with few side effects.
The application of the novel design method can effectively lead to tive study.Inclusion criteria: Male patients with AGA in Hamilton Grade V-VI; patients aged from 18 years to 65 years; AGA patients underwent FUE from March 2020 to March 2022; the number of hairs in the donor area was sufficient; non-surgical treatments such as drug therapy, laser therapy, and mesotherapy were ineffective for these patients.Exclusion criteria: Infectious diseases associated with scalp soft tissue; serious mental illness; any previous history of systemic diseases, endocrine disorders, bleeding or keloid.The study has taken into account the Declaration of Helsinki.All patients were informed of and consented to the study.

K
E Y W O R D S androgenetic alopecia, follicular unit extraction megasession, surgical design | 3397 DI et al.

F I G U R E 2
Isolation of hair follicular grafts.(A) After extraction, 2-4 assistants trim the extracted follicular grafts with 3x magnifying glasses.(B) The assistant divides extracted follicular grafts into 1-hair thin units, 1-hair thick units, 2-hair units, and 3-hair units.Then, the hair units are placed in the disposable divided surgical kidney dish with 100 hair follicles in each square.F I G U R E 3 Different hair units in hair transplant surgery.(A) 1hair thin unit.(B) 1-hair thick unit.(C) 2-hair units.(D) 3-hair units.
Satisfaction rating survey of patients and the doctor was performed no less than 6 months after surgery.The Likert scale was used to rate the outcome of the procedure, which included different levels of satisfaction (1 point = very unsatisfied, 1 point = very unsatisfied, 2 points = unsatisfied, 3 points = neutral, 4 points = satisfied, and 5 points = very unsatisfied).The following questions were assessed:1.How natural do you think the post-surgery result looks? 2. How satisfied are you with the whole procedure of hair transplant surgery?

1 . 2 . 3 F I G U R E 8 4 F I G U R E 7
How natural do you think the postsurgery result looks?How satisfied are you with the whole procedure of hair transplant surgery?Patient-rated Likert scores.Likert scores rated by the doctor (1 point = very unsatisfied, 1 point = very unsatisfied, 2 points = unsatisfied, 3 points = neutral, 4 points = satisfied, and 5 points = very unsatisfied).The average score given by doctor for naturalness of hair is as high as 4.61, and the average score of doctor overall satisfaction with the procedure is as high as 4.75.Doctor-rated Likert scores.Likert scores rated by the patient (1 point = very unsatisfied, 1 point = very unsatisfied, 2 points = unsatisfied, 3 points = neutral, 4 points = satisfied, and 5 points = very unsatisfied).The average score given by patients for naturalness of hair is as high as 4.72, and the average score of patients' overall satisfaction with the procedure is as high as 4.64.

F I G U R E 9
Representative clinical photographs of a 49-year-old patient with Norwood-Hamilton stage V alopecia, who underwent follicular unit extraction megasession treatment with 4367 hair units (1350 1-hair units, 2700 2-hair units, and 317 3-hair units).(A, D) Preoperative views.(B, E) 1 day after surgery.(C, F) 6 months follow-up.In FUE megasession operation, we introduced a novel surgical design method.Through the innovative application of the surgical design, the technique largely makes up for some deficiencies in FUE megasession and provides convenience for medical staff.In the research, 36 male patients with AGA in Hamilton Grade V-VI were enrolled.All the participants underwent FUE megasession treatment with the specific surgical design.The investigators observed the patients' general conditions, surgical information, naturalness of hair, and patient and doctor satisfaction level and adverse reactions.Before surgery, the average age of patients was 36.8 ± 9.6 years (aged from 22 to 62 years), and average duration of disease was 8.3 ± 3.8 years (aged from 3 to 15 years).We harvested an average of 3705 ± 383 grafts, and each operation contained a number of hair grafts greater than 3000.Recipient density ranged from 30 FUs/cm 2 to 50 FUs/cm 2 , which provided enough hair density to cover the exposed scalp.Besides, the total operation time was 10.6 ± 0.9 h, and all procedures can be completed in 1 day.After surgery, patient-rated Likert score for naturalness of hair was as high as 4.72, and the doctor rated 4.61.The results revealed that the above surgical design brought a natural post-operative hairstyle for Asians.Moreover, the FUE megasession with the specific surgical design showed high satisfaction among patients.Patient satisfaction score was up to 4.64, and the doctor scored 4.75.No serious side effects occurred in the study, and patients are relatively safe in the procedure.

F I G U R E 1 0
Representative clinical photographs of a 27-year-old patient with Norwood-Hamilton stage V alopecia, who underwent follicular unit extraction megasession treatment with 3050 hair units (1100 1-hair units, 1750 2-hair units, and 200 3-hair units).(A, D, G) Preoperative views.(B, E, H) 1 day after surgery.(C, F, I) 6 months follow-up.

F I G U R E 11
Representative clinical photographs of a 23-year-old patient with Norwood-Hamilton stage VI alopecia, who underwent scalp medical tattoo and follicular unit extraction megasession treatment with 4284 hair units (1100 1-hair units, 2550 2-hair units, and 634 3-hair units).(A, D, G) Preoperative views.(B, E, H) 1 day after surgery.(C, F, I) 6 months follow-up.relatively natural density and appearance in one operation.Because of its remarkable effect, high satisfaction level and few postoperative complications, FUE megasession with the introduced surgical design has great potential for Asian high-grade AGA patients.