GFP-labeled Schwann cell-like cells derived from hair follicle epidermal neural crest stem cells promote the acellular nerve allografts to repair facial nerve defects in rats.

BACKGROUND: Acellular nerve allografts (ANAs) have been successfully applied to bridge facial nerve defects, and transplantation of stem cells may enhance the regenerative results. Up to now, application of hair follicle epidermal neural crest stem cell-derived Schwann cell-like cells (EPI-NCSC-SCLCs) combined with ANAs for bridging facial nerve defects has not been reported. METHODS: The effect of ANAs laden with green fluorescent protein (GFP)-labeled EPI-NCSC-SCLCs (ANA + cells) on bridging rat facial nerve trunk defects (5-mm-long) was detected by functional and morphological examination, as compared with autografts and ANAs, respectively. RESULTS: (1) EPI-NCSC-SCLCs had good compatibility with ANAs in vitro. (2) In the ANA + cells group, the GFP signals were observed by in vivo imaging system for small animals within 8 weeks, and GFP-labeled EPI-NCSC-SCLCs were detected in the tissue slices at 16 weeks postoperatively. (3) The facial symmetry at rest after surgery in the ANA + cells group was better than that in the ANA group (p < 0.05), and similar to that in the autograft group (p > 0.05). The initial recovery time of vibrissal and eyelid movement in the ANA group was 2 weeks later than that in the other two groups. (4) The myelinated fibers, myelin sheath thickness and diameter of the axons of the buccal branches in the ANA group were significantly worse than those in the other two groups (P < 0.05), and the results in the ANA + cells group were similar to those in the autograft group (p > 0.05). CONCLUSIONS: EPI-NCSC-SCLCs could promote functional and morphological recovery of rat facial nerve defects, and GFP labeling could track the transplanted EPI-NCSC-SCLCs in vivo for a certain period of time. These may provide a novel choice for clinical treatment of peripheral nerve defects.

Evolución de la técnica follicular unit extraction (FUE) / Evolution of the follicular unit extraction (FUE) technique

El microtrasplante capilar, método FUE, es la cirugía para la recuperación capilar que consta en la extracción de unidades foliculares con punches de distintos diámetros y longitudes, desde una zona llamada dadora, generalmente occipital y/o temporal aunque pueden utilizarse otras partes del cuerpo como barba, tórax, abdomen y pubis, para luego de seleccionarse y conservarse en forma adecuada ser implantadas en la llamada zona receptora. Tanto los avances en la técnica como en el uso de instrumental de última generación generan resultados mejores y más naturales, con una recuperación más rápida y menor daño de sus zonas dadoras.

Hair transplant, FUE method, is surgery for hair recovery that consists of the extraction of follicular units with punches of different diameters and lengths, from an area called the donor; usually occipital and/or temporal; although they can be used on other parts of the body such as beard, thorax, abdomen and pubes. After being appropriately selected and preserved, they are implanted in the so-called receiving area. Both advances in technique and in the use of cutting-edge instruments generate better and more natural results, with faster recovery and less damage to the donor areas

Autologous follicular unit extraction transplant for postburn cicatricial alopecia: A single-center's retrospective case series.

BACKGROUND AND RATIONALE: Cicatricial alopecia not only affects patients' appearance but also has negative effects on their physical and mental well-being, as well as their daily lives. Therefore, it is essential to provide proactive treatment to patients. OBJECTIVE: To explore the clinical effects of autologous follicular unit extraction (FUE) transplantation in the treatment of secondary scarring alopecia caused by burn, and to evaluate its effectiveness. METHODS: A retrospective observational study has been conducted, which included 41 patients with secondary scarring alopecia caused by burn. All patients underwent initial autologous FUE hair transplantation surgery, and the occurrence of postoperative complications was monitored. Patient satisfaction was evaluated after 12 months post-surgery. RESULTS: Satisfaction assessments were conducted for all 41 patients. Out of the total, 31 individuals expressed being very satisfied, 7 individuals reported being satisfied, and 3 individuals indicated being not very satisfied. Among the patients, 3 experienced complications, including herpes in the donor area for one patient, temporary hair loss for another patient, and thick scab for the third patient. CONCLUSION: FUE hair transplantation yields positive results for secondary scarring alopecia caused by burn. It offers natural hair growth patterns, minimal trauma, quick recovery, high patient satisfaction, and few complications.

Large-Scale Preparation of Hair Follicle Germs Using a Microfluidic Device.

Hair follicle morphogenesis during embryonic development is driven by the formation of hair follicle germs (HFGs) via interactions between epithelial and mesenchymal cells. Bioengineered HFGs are potential tissue grafts for hair regenerative medicine because they can replicate interactions and hair follicle morphogenesis after transplantation. However, a mass preparation approach for HFGs is necessary for clinical applications, given that thousands of de novo hair follicles are required to improve the appearance of a single patient with alopecia. In this study, we developed a microfluidics-based approach for the large-scale preparation of HFGs. A simple flow-focusing microfluidic device allowed collagen solutions containing epithelial and mesenchymal cells to flow and generate collagen microbeads with distinct Janus structures. During the 3 days of culture, the collagen beads contracted owing to cellular traction forces, resulting in collagen- and cell-dense HFGs. The transplantation of HFGs into nude mice resulted in highly efficient de novo hair follicle regeneration. This method provides a scalable and robust tissue graft preparation approach for hair regeneration.

Paradigm Shift from Linear Strip to Follicular Unit Excision in Hair Restoration Surgery.

Follicular unit excision (FUE) is a very effective and valuable modality for obtaining donor hair follicles using manual, motorized, or robotic devices to harvest individual donor follicular units in situ without a linear donor scar or visible scarring making it ideal for patients who wish to wear their hair short and hide signs of surgery. Over the past two decades, FUE has become increasingly popular, and the rising demand for FUE has driven the worldwide market size of hair restoration surgery (HRS) to an unprecedented height.FUE has revolutionized the HRS industry and offers excellent cosmesis and high patient satisfaction. Unfortunately, a large part of the favorable appeal of FUE is due to false claims that it is "minimally invasive," "scarless," or "not even surgery." Most patients opt-in for FUE due to these misconceptions, which are advertised by "black-market" clinics offering low-cost FUE surgery performed by amateur, nonprofessional technicians on unsuspected patients. The technique appears deceptively simple, and many neophyte surgeons falsely believe that the learning curve of FUE is short because the barrier of entry is low and no previous surgical skill is required. Nevertheless, injuries on grafts are extremely easy to occur since FUE is a blind technique and can be minimized only with excellent technique, which takes years to master.FUE actually presents unique challenges for the surgeon and carries potential long-term permanent side effects if not performed properly. The surgeon must have a thorough understanding of the nuances of the FUE surgical technique to ensure consistent graft quality and favorable cosmesis of both donor and recipient areas. Efficient FUE requires dexterity, training, dedication, devotion, enthusiasm, cognitive clarity, scientific knowledge, experience, and an extended learning curve.FUE is an invaluable addition to the armamentarium of a hair restoration surgeon but has to be judiciously performed.

Follicular Unit Excision (FUE) Basics.

Follicular unit excision (FUE) has risen to the forefront as the world's most popular hair transplant procedure. However, most writing on this subject has catered to the advanced practitioner. The goal of this article will be to focus on safe planning and decision making along with key technical steps that will guide the beginner surgeon to harvest a graft safely and to harvest the donor area in a uniform way to avoid overharvesting. Topics covered in this article also include instrumentation and decision making between FUE versus linear strip excision.

Instrumentation and Devices Specific to Follicular Unit Excision.

The volume of hair transplantation procedures done via the follicular unit excision (FUE) harvesting technique has increased tremendously over the last few years. With this growth, new advances in technology have come along. The wide variety of instrumentation and devices can be overwhelming, especially for a novice surgeon. This chapter aims to discuss the relevant aspects of FUE and its relationship to the devices that are used to harvest grafts. The development and overview of all the major types of instrumentation will be reviewed.

Patient Selection for Follicular Unit Extraction versus Linear Strip Donor Harvesting.

Follicular unit grafts can be harvested using two methods: strip follicular unit transplantation and follicular unit excision. Each method can generate outstanding results, but both are uniquely different with respect to the advantages and disadvantages they offer. Devising a sound surgical plan is instrumental to assure that a patient's short-term and long-term goals can be met, but creating the best plan possible for the graft harvest process is not straightforward. This paper will review the various advantages and disadvantages of each graft harvest method, along with their short-term and long-term ramifications, so as to provide insight into the process by which a sound surgical plan can be developed for any patient seeking surgical hair restoration.

Utility of Follicular Unit Excision Using Nonscalp Donor Hair.

Nonscalp donor hair harvesting or body hair transplantation offers patients an additional source of donor hair in cases when the scalp does not have an adequate supply for the intended recipient area. The most common applications for nonscalp donor hair are for patients with advanced hair loss or to camouflage scarring from prior hair restoration procedures. For patients with available body hair, the beard is probably the best source followed by the chest and abdomen. Combined, these sources may be able to provide thousands of additional grafts for transplantation. Nonscalp hair donor harvesting is technically challenging and should be performed by those with extensive experience in follicular unit excision surgical techniques.

Concepts, Terminology, and Innovations in Follicular Unit Excision Hair Restoration Surgery.

Follicular unit excision (FUE) has emerged as the preferred method for hair transplants. Standardized terms and definitions established by members of the International Society of Hair Restoration Surgery and prominent hair restoration surgeons have become the standard, enabling effective knowledge sharing. This chapter provides an overview of the terminology relating to the field.The historical evolution of FUE and its pivotal role in modern hair transplantation is summarized. Anatomical terminology and graft-related definitions follow, providing insights into the scalp's complex structures and graft characteristics. The subsequent sections detail the terminology associated with graft excision and extraction, shedding light on the precise techniques and procedures employed. An exploration of various FUE techniques and the evolving landscape of FUE devices underscores the continual refinement of hair restoration practices. The chapter proceeds to discuss the "safe'" scalp donor zones, donor assessment terminology, and elements in identifying the optimal donor area for a successful FUE procedure. Additionally, punch dynamics and technique characteristics are examined, emphasizing their pivotal role in achieving superior FUE outcomes. The chapter concludes by discussing the classification of punches and graft evaluation terms, offering insights into the tools, and criteria used to assess graft quality and viability.

Follicular Unit Excision-Linear Ellipse Donor Harvesting Technique: Combining Standard Follicular Unit Excision with Follicular Unit Excision inside a Linear Strip (Modified Linear Strip Excision) to Optimize Graft Yield.

Follicular unit excision (FUE) graft dissection has become the dominant method of donor harvesting globally, however, only a percentage of donor hair can be excised inside the safe donor area before visible donor thinning occurs. Compared to linear strip excision (LSE) where all follicular units inside the harvested ellipse of hair are used, FUE poses substantial limitations for lifetime graft yield and, therefore, cosmetic coverage in patients with advanced pattern hair loss. This paper reviews how combining the donor harvesting methods of FUE and LSE has been shown to optimize graft yield while minimizing the risk of donor depletion from overharvesting. It then describes a surgical technique called FUE-Linear Ellipse (FUE-LE) where FUE dissection of grafts inside a demarcated linear ellipse eliminates the need for a large dissection team which has posed a barrier for many new practices that offer both the donor harvesting methods. For practices that currently offer only FUE, the addition of the LSE method by the modified FUE-LE technique is possible without specialized staff training or associated equipment costs. In this paper, surgery practices that have adopted this technique will report on their experiences. Hair restoration surgeons are encouraged to provide both methods of donor harvesting (FUE and LSE using FUE-LE) in order to optimize graft yield for patients and avoid long-term donor depletion. Based on limited experience, it appears the technique of FUE-LE will help achieve this goal.

Advancements in Graft Placement Techniques.

For decades, the placement of follicular units (FUs) into incisions in the recipient area was exclusively carried out using forceps. In 1992, Dr. Choi introduced an instrument known as the "implanter," which had the advantage of simultaneously creating incisions and placing FUs without damaging sensitive parts. Its initial popularity was greater in the East, primarily due to the characteristics of Asian hair. Asian hair is typically straight and thick, with FUs mostly consisting of just one or two hair.With the description of the follicular unit excision (FUE) technique in 2002 and its widespread adoption nearly a decade later, the advantages of using the implanter also gained popularity in the West. The uniformity in the size of FUs provided by the FUE technique and the possibility of delegating the placement were key attractions in the use of this placement tool. In addition to the traditional Korean implanter with a sharp needle, other implanters and inserters have been described.The choice of implantation technique depends on individual adaptation and the advantages and disadvantages offered by each instrument. Although forceps allow for safe placement in the hands of well-trained teams, the increased fragility of FUs obtained with the FUE technique has led to the growing acceptance of techniques that employ implanters and inserters.

Follicular Unit Excision in Patients of African Descent: A Skin-Responsive Technique.

BACKGROUND: Follicular unit excision is a favored minimally invasive hair transplantation method. However, it is suboptimal for many patients of African descent because of wide variations in hair and skin characteristics. OBJECTIVE: To evaluate the performance of a skin-responsive follicular unit excision device, which accommodates hair curliness, skin thickness, and firmness in patients of African descent. MATERIALS AND METHODS: The authors retrospectively evaluated patients who underwent scalp follicular unit (FU) excision using a skin-responsive technique at 7 multinational clinics. The preoperative donor grading for the anticipated difficulty used a scale with Class V indicating the highest degree of hair curliness, skin thickness, and firmness. RESULTS: Of 64 eligible patients (45 males and 19 females), 28 had Class V FU excision donor grades. The mean transection rate for all patients was 3%-6%, which was highest in class V patients. Skin thickness and firmness had a greater effect on the maximum transection rate than hair curliness. Only 19 or 18 G punches were used. CONCLUSION: The authors report consistence success of a new skin-responsive FU excision device for all patients of African descent with a mean graft transection rate of less than 10%. The findings support skin thickness and firmness as major influencers of graft attrition rate.

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

BACKGROUND: 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. OBJECTIVE: The goal 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. METHODS: Thirty-six Asian male patients with AGA in Hamilton Grade V-VI were enrolled in the research. All 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. RESULTS: Before surgery, the average age of patients was 36.8 ± 9.6 years, and average duration of disease was 8.3 ± 3.8 years. During surgery, we harvested an average of 3705 ± 383 grafts. Recipient density ranged from 30 FUs/cm2 to 50 FUs/cm2 , and the total operation time was 10.6 ± 0.9 h. After surgery, patient-rated Likert score for naturalness of hair was as high as 4.72, and the doctor rated 4.61. Patient satisfaction score was up to 4.64, and the doctor scored 4.75. No serious side effects occurred in the study. CONCLUSION: 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 relatively 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.

Depth control in follicular unit excision: A new classification from a detailed analysis of 30 patients undergoing FUE technique for hair restoration.

BACKGROUND: In follicular unit excision (FUE), the concept of depth control (DC) has been created to minimize the risk of hair follicle damage. AIM: To analyze DC variation in different parts of the safe donor area of scalp; to propose Boaventura's new DC classification for hair restoration surgery using the FUE technique. PATIENTS/METHODS: Thirty male patients underwent hair restoration surgery. The donor area was distributed into 14 zones, with the minimum depth required for at least three atraumatic extractions of the grafts. When the extraction was not successful, 0.5 mm was added until reaching three follicular units, determining the DC area. RESULTS: Approximately 2000 extractions were performed on each patient to determine DC. For some areas, greater depth (2.54 ± 0.10 mm) was necessary. Fifty-eight percent of follicular units were extracted with 2.0 mm DC, and 3.8% required 3.5 mm DC. Thus, according to Boaventura's new classification for DC, grade I ≥ 2.00 mm, grade II from 2.1 to 3 mm, and grade III > 3.0 mm. CONCLUSION: There is variability in the DC of follicular units within the different areas of the safe donor zone. Moreover, we have proposed a new DC classification, which would represent a valuable estimation of surgery demand.

Natural Reconstruction: A Comprehensive Standardized Operating Procedure for Restoring Eyebrow Loss Due to Scarring.

BACKGROUND: Scarring that results in eyebrow loss is a cosmetic problem that can result in severe psychological distress. Although hair transplantation is increasingly used for eyebrow restoration, graft loss may occur, preventing achievement of desired results. Single-hair follicle transplantation, however, may be effective. The authors describe outcomes of a standardized method of eyebrow reconstruction, involving single-hair follicle transplantation combined with follicular unit extraction, in patients with absent eyebrows because of scarring. METHODS: This study was approved by the institutional ethics committee of Nanfang Hospital and all patients provided written informed consent before surgery. The medical records of patients who underwent eyebrow reconstruction from 2012 to 2019 for eyebrow loss caused by scar formation were reviewed retrospectively. Outcomes evaluated included satisfaction, graft survival rate, and long-term complications. A nine-step standardized operating procedure was established for eyebrow reconstruction in patients with eyebrow absence attributable to scarring. RESULTS: During the study period, 167 patients (205 eyebrows) underwent eyebrow reconstruction. Following the first stage of reconstruction, 95 percent of patients were highly satisfied with the density and natural appearance of their eyebrows. The average graft survival rate was 85 percent (range, 70 to 90 percent), significantly higher than the 75 percent survival rate previously reported. Fewer than 5 percent of patients underwent the second stage of reconstruction, with these patients expressing satisfaction with their outcomes. No obvious complications were observed. CONCLUSION: This standardized method may optimize outcomes in patients with eyebrow absence attributable to scarring. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Evaluation of efficacy of follicular unit extraction versus follicular unit extraction with platelet rich plasma in treatment of cicatricial alopecia.

BACKGROUND: Follicular unit extraction (FUE) is a minimally invasive surgery that is becoming popular in hair restoration in cicatricial alopecia (CA). AIM: Evaluation of FUE with or without platelet rich plasma (PRP) in scarring alopecia. PATIENTS AND METHODS: Twenty patients with CA were randomized into two groups. Group A (10 patients) underwent FUE, group B (10 patients) underwent FUE + PRP. PRP was injected 1 week before surgery, then monthly after surgery for 3 months. Follow up was done after 3, 6 and 12 months by calculating the density of surviving follicular units and the survival rate. RESULTS: In group A, there was statistically significant increase in mean survival rate which was 30.30%. At 3 months, 67.26% at 6 months and 78.15% at 12 months. In group B, there was a significant increase in mean survival rate being 30.14% at 3 months, 58.75% at 6 months and 69.74% at 12 months. There was no significant difference between both groups at anytime during follow up period. CONCLUSION: Follicular unit extraction is a preferred procedure for hair restoration in CA with few side effects. The role of PRP in HT is controversial. In the present study, PRP does not significantly affect the survival rate of hair grafts.

Frontal-Temporal Triangle Area Hair for Eyebrow Restoration in Asians: A Comparative Study With Periauricular and Occipital Hair.

BACKGROUND: The frontal-temporal triangle area (FTTA) hair has a slow growth rate and thin caliber, which are similar to those of eyebrow hair. However, a comparison of cosmetic outcomes between FTTA and other scalp hair grafts in eyebrow transplantation has not been performed. OBJECTIVE: To compare the cosmetic outcomes of FTTA hair and periauricular and occipital area (POA) hair in eyebrow restoration. METHODS: A retrospective analysis of 155 patients with FTTA or POA hair transplants was performed. Comparative variables included patient characteristics, hair density, diameter, percentage of one-hair follicular units (FUs), number of transplanted FUs, harvesting time, transection rate, hair survival rate, frequency of eyebrow trimming, and patient satisfaction. RESULTS: There was a significant difference in hair density, diameter, percentage of one-hair FUs, and harvesting time between the FTTA and POA hair transplants. The FTTA hair grew significantly slower than the POA hair did. The patients in the FTTA group trimmed their postoperative eyebrows at a significantly longer interval than those in the POA group. The percentage of patients who were very satisfied with the surgery results was higher in the FTTA group. CONCLUSION: The FTTA hair grafts can provide aesthetically pleasing cosmetic results in eyebrow restoration.

The role of autologous micrografts injection from the scalp tissue in the treatment of COVID-19 associated telogen effluvium: Clinical and trichoscopic evaluation.

The clinical presentation of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2 COVID-19) varies from asymptomatic infection to a life-threatening, multiorgan disease. One of these manifestations is telogen effluvium (TE) which is characterized by diffuse hair loss occurring in patients previously infected with SARS-CoV-2 and lasts ~3 months, after which excessive hair loss follows. Hair follicles are known to contain a well-characterized niche for adult stem cells which is the bulge containing epithelial and melanocytic stem cells. Stem cells in the hair bulge, a demarcated structure within the lower permanent portion of hair follicles, can generate the interfollicular epidermis, hair follicle structures, and sebaceous glands. This study aims to evaluate autologous micrografts from scalp tissues as a therapeutic modality in the management of TE caused by COVID-19. Twenty patients of previous COVID-19 infection suffered from TE were included in this study for human follicle stem cells micrograft scalp treatment and they were evaluated after 3 months of treatment and after 6 months. There was significant improvement of the hair thickness and density compared with the start of the treatment and 6 months of follow-up. Autologous micrograft of the scalp showed marked improvement in the treatment of COVID-19 TE.