Recipient site scalp necrosis: A rare postoperative complication of hair transplantation

Recipient area scalp necrosis is considered a potential complication of hair transplantation, but has rarely been reported. A small number of patients have developed scalp necrosis after hair transplantation with the widely used Follicular unit excision (FUE) technique. There are no guidelines to prevent and manage this complication. The aim of this study was to provide an insight into the pathogenesis, prevention, and management of scalp necrosis following hair transplantation.


| C A S E REP ORT
From 2012 to 2021, we found that four patients developed scalp necrosis after hair transplantation using the FUE technique.The clinical information for these four patients is displayed in Table 1.

| Case1
An 18-year-old male patient suffered cicatricial alopecia for over years.A total of 3210 hair grafts were implanted into his left temporal and frontal area, achieving an average density of 40 units/cm^2.The entire process, from punching to graft insertion, took approximately 30 min.However, a mere 3 days post-operation, the young man began to experience pain at the transplantation site.Upon examination, it was evident that the affected area bore a layer of eschar, accompanied by traces of yellow exudate.The dimensions of the lesions measured around 11 × 13.5 cm.In the days that followed, the eschar naturally shed, but the pustules magnified and coalesced, revealing extensive necrotic ulcerations (as shown in Figure 1).Immediate medical intervention saw the patient being administered broad-spectrum antibiotics intravenously on a daily basis.Bacterial cultures from the exudate pinpointed the presence of Staphylococcus aureus.Rigorous daily cleaning of the lesion was performed using chlorhexidine and diluted hydrogen peroxide.Any discernible soft abscesses were incised to facilitate proper drainage.Mupirocin ointment was applied atop the crust to both curb the local bacterial proliferation and expedite its shedding.Following a week of the TA B L E 1 Clinical information for the four patients with scar necrosis following hair transplantation.the end (as illustrated in Figure 1).By the third week, the wound had fully healed, leaving behind a few atrophic scars.

| Case 2
A 23-year-old male had suffered hair loss due to androgenetic alopecia (AGA).Carefully, 2090 hair grafts were transplanted to his In response, the patient was intravenously administered cefuroxime sodium, a broad-spectrum antibiotic, at a dosage of 0.25 g/ day for three consecutive days.Following this, the necrotic tissue was diligently excised until fresh granulation tissue emerged (illustrated in Figure 2).Subsequently, mupirocin ointment was applied to the wound.Remarkably, with the interventions described, the skin lesions showed significant improvement within a span of 14 days.

| Case 3
A 45-year-old male had been grappling with hair loss attributed to AGA and subsequently sought hair transplantation.3480 hair grafts were transplanted onto his central midscalp, crown, and frontal regions, with an achieved density averaging 40 units/cm^2.
The intricate process, from the initial punch to the final graft insertion, extended over a period of 30 h.Unfortunately, just 3 days post-surgery, the patient reported pain at the transplantation site.
A thorough physical examination revealed a sizable necrotic patch measuring 13.5 × 6.5 cm on his recipient scalp, stretching from the forehead's hairline down to the parietooccipital junction.Within this afflicted zone, sporadic black eschars and purulent discharges were discernible (as visualized in Figure 3).
The patient was promptly administered cefuroxime sodium, a broad-spectrum antibiotic, at a dosage of 0.25 g/day over 3 days.
Bacterial culture of the discharge detected the presence of s. aureus (highlighted in Figure 3).Based on the culture results and drug sensitivity analysis, the antibiotic regimen was adjusted to mupirocin.
All emergent pustules were incised, and the affected area was diligently cleansed using chlorhexidine and diluted hydrogen peroxide.
Merely 5 days posttreatment, the eschars naturally sloughed off, revealing nascent granulation tissue (depicted in Figure 3).Ten days post-operation, the wound was fully healed.Ultimately, the patient expressed contentment with the graft survival rate, seeing no need for a secondary implantation.

| Case 4
A 30-year-old man, previously diagnosed with AGA, had undergone a hair transplantation using the FUE technique.Six days post-procedure, he was admitted to our facility due to alarming scalp complications.A segment of his midscalp, measuring 2*4 cm, had inexplicably detached after being punched (as shown in Figure 4).Following this, a localized ulceration surfaced within that region and swiftly spread to the neighboring scalp (visualized in Figure 4).The surrounding scalp exhibited a pronounced F I G U R E 3 A 45 years old man underwent hair transplantation in the frontal and vertex scalp (above, left).Scattered black eschars and pustules were developed in the frontal scalp three days after the operation (above, right).The eschars began to fall off, and the purulent secretion decreased after the treatment for three days (below, left).S. aureus was generated in the wound secretion bacterial culture test.(below, right).
cyanosis, hinting at its potential spread.Between days 3 and 6, the primary lesion and reddened areas evolved into a liquefactive necrotic state, merging into a subcutaneous compartment of 11.5 × 7.5 cm (captured in Figure 4).Cases 1-3 received timely treatment and had a good prognosis.
However, in case 4, due to untimely and improper treatment, the lesion developed extensively and deeply, which not only delayed wound healing, but also resulted in complete loss of grafts.It is crucial to identify the cause of scalp necrosis.However, the specific pathology resulting in necrosis remains inconclusive.

| Pathogeny resulting in necrosis following hair transplantation
Insufficient blood supply to the recipient area is considered the main cause of necrosis. 12The bilateral anterior scalp is supplied by the frontal and parietal superficial temporal artery; thus, the central area is the least vascularized area of the scalp 2,13,14 ; moreover, vascularization is reduced in the scalp of patients with scarring and AGA. 15 In our study, three cases with AGA always involved the central scalp that is the poor vascularized area, and one case without AGA involved the scar area.Therefore, insufficient blood The differential diagnosis includes herpes zoster, postradiation ulcers, folliculitis, ulcerated skin tumors, giant cell arteritis, and pyoderma gangrenosum. 17,18Folliculitis is always characterized by several pustules, papules, and erythematous nodules, which are solitary and without confluence. 7The lesions are always self-limited.Scalp necrosis due to giant cell arteritis occurs mostly in elderly patients, and physical examination reveals a pulseless temporal artery.The lesions remarkably improve upon glucocorticoid treatment and do not respond to antibiotics. 19-27

| Prevention and treatment of scalp necrosis during perioperative period
Early identification and proper treatment are crucial for prevention and treatment of scalp necrosis during the preoperative, intraoperative, and postoperative periods (Table 2).Before hair transplantation, a detailed medical history should be taken about risk factors related to circulation as well as surgical history of the scalp and ar-

| CON CLUS ION
Although scalp necrosis has a very low incidence, its consequences can be devastating.Comprehensive management, including timely

CO N FLI C T O F I NTER E S T S TATEM ENT
All the authors have no financial interest to declare.
there was a notable improvement in the lesion's condition and a reduction in secretion.Despite the progress, some grafts unfortunately did not survive, detaching themselves in mid and frontal regions, achieving a density averaging 43 units/ cm^2.The procedure, spanning from the initial punch to the final graft insertion, took roughly 30 min.Distressingly, around the fourth day post-operation, the patient began to experience pain in the grafted area.A meticulous clinical evaluation unveiled two distinct lesions: one centrally located on the mid-scalp and the other on the left frontal region.The central lesion, measuring 3 × 4 cm, exhibited pallid skin encircled by a reddish hue.Its center darkened, hinting at potential necrosis.Similarly, the lesion on the left frontal area presented as a 3 × 4 cm dark necrotic patch (as depicted in Figure 2).

F
I G U R E 1 (A) 18 year old man with scalp necrosis in the recipient site after hair transplantation.A large eschar appeared in the temporal region at the day 3. (B) Partial eschars fell off along with purulent secretion.(C) The local condition was improved and purulent secretion was significantly reduced with topical and systemic treatment.FI G U R E 2 A 23 years old man with recipient-site scalp necrosis following hair transplantation.A superficial necrotic ulceration and a pallor area were developed in his frontal scalp and midscalp (left).Fresh granulation tissue appeared after treatment (right).
Local physicians had attempted to rectify the issue by applying growth factors and ointments to the lesion, but to no avail.Hoping for superior medical intervention, the patient was transferred to our care.He was promptly treated with both topical and systemic F I G U R E 4 Digital photographs at day 0-60 for case 4 who underwent hair transplantation due to AGA.At the Day 0, a 2 × 4 cm scalp in the center area fell off immediately after punching and the scalp around the lesion turned cyanosis rapidly.At the Day 6, large scalp ulceration was developed.At the day 10-20, the necrosis was confined and improved significantly after the application of antibiotics and conservative debridement treatment.Day 20-60: the process of wound closure.broad-spectrum antibiotics.Relying on bacterial culture and drug sensitivity tests, the treatment was tailored to include ampicillin (4 g/day) and gentamicin (80 mg/day).Thankfully, by the third day under our care, the necrosis was contained.From day 13 to 16 post-operation, the ulceration bore a crust of eschar (documented in Figure4).Any loose scabs around the perimeter were excised, revealing an underlying pus collection.A meticulous cleaning routine was established, utilizing chlorhexidine and diluted hydrogen peroxide daily.On day 20, the entire eschar was successfully removed (as depicted in Figure4), revealing a much-improved wound devoid of pus.Between days 24 and 27, regenerative epithelium started appearing along the wound's edge, harmoniously aligning with fresh granulation tissue.Two months post-complication, the wound had remarkably healed and was completely sealed (illustrated in Figure4).Regrettably, all grafts within the necrotic zone had been lost.Consequently, a secondary hair transplantation was undertaken, yielding impressive results marked by a gratifying graft survival rate.3| DISCUSS IONScalp necrosis is always considered a potential complication of hair transplantation, but has a very low incidence.The outcome after scalp necrosis can be devastating.The commonly involved area was the center of the scalp.Early treatment with local and systemic broad-spectrum antibiotics can control the progression of necrosis.
supply may have been a cause of necrosis in this study.However, necrosis occurred with bacterial infection in the four patients.This raises the question of whether necrosis is mainly caused by infection or insufficient blood supply.Necrosis was confined after antibiotic treatment, suggesting that infection plays an important role as well in development of necrosis.Tsai Ching Chou et al. postulated that multiple punch wounds may cause skin barrier dysfunction, rendering the scalp more susceptible to microbiological invasion.16Tulin Mansur et al. held the same view and also suggested that surgical psychogenic stress might suppress the patient's immune defense5 ; therefore, dense packing may increase susceptibility and promote receipt area infected, and then infection accelerated the progression of necrosis.In case 4, necrosis occurred immediately after holes were punched with a high dense(n>50/cm 2 ) in the fronalcenter area.Given that bacteria are unlikely to cause acute scalp necrosis within 30 min, weaker blood and/or stress response may be the main cause of necrosis in this case.Subsequently, wound induces secondary infection and untimely treatment resulted in further deterioration.Of the four cases, no one had risk medical history(i.e., hypertension, smoking and diabetes mellitus) associated with perturbation of circulation or infection.Vascular transection may be another factor for necrosis, while continuous bleeding was not observed after punching, and further examination found no subcutaneous hematoma, implying that the FUE technique is associated with minimal trauma.Therefore, early poor blood supply and dense punching increased the incidence of necrosis.After wound infection was controlled, and collateral circulation was established in the later stage, then necrosis gradually improved.In conclusion, multiple punch wounds make the scalp such as the center or scar area that already has a poor blood supply, especially in AGA patients or scar area, more susceptible to develop necrosis.
teritis.Medical history such as hypertension, smoking and diabetes mellitus can increase in the possibility for necrosis.Patients should stop smoking for 1 month before and after the operation.Diabetes and arthritis should be well controlled before surgery.If the patient has a high risk of infection, prophylactic antibiotics can be injected 30 min before surgery, and an additional dose can be given if the surgery lasts longer than 3 h.Use of a trichoscopy device and capillary filling test are recommended to evaluate the blood supply in patients with scars in the recipient area.Moreover, injection of platelet-rich plasma, and topical application of minoxidil before the operation might minimize the risk of necrosis.28,29Autologous fat grafts that consist primarily of adipose-derived stromal cells and svf-gel can improve the scar quality as well.During the operation, Technical factors associated with FUE that are closely related to recipient ischemia include dense packing, epinephrine use, vascular transection, and deep punching.The density should be less than 50 units/ cm 2 , 8 especially in the center scalp, scar area and AGA patients.A thin 23 G needle was used to gently punch holes at a moderate depth of 4.5 mm.Tumescent fluid can be used to increase the tissues' distance and avoid damaging the underlying neurovasculature.

1 .
Autologous fat grafts, PRP injection and topical minoxidil treatment may improve the woundhealing capacity and blood supply Diabetes and hypertension Adequate control Smoking Quit smoking at least 1 month before operation Giant cell arteritis Glucocorticoids AGA / scalp surgery Blood supply evaluation in receipt area (trichoscopy) and reduce grafts density properly Intraoperation Using proper recipient-tumescent fluid to increase the distance between the needle and underlying neurovasculature 2.Density <50 unit/cm2(less in scar area and AGA patients) 3.Punching depth is 4-5 mm to avoid vascular transection 4.Prophylactic antibiotics injection is for long surgical time 5.Epinephrine Concentration<1/200000 and slower infiltration of tumescent When risk signs such as pain, dark, bruising and pallor appear: Stop hair transplant Increase the reperfusion time from graft harvesting to implantation Apply nitroglycerin spray Intraoperation Infection Take care of the recipient site, mupirocin ointment and systemic antibiotic use Debridement and drainage Ischemia Topical nitroglycerin or surgical exploration TA B L E 2 Necrosis prevention and treatment strategies.and proper interventions, can prevent further deterioration, improving the prognosis and increasing the graft survival rate in the necrotic area.FU N D I N G I N FO R M ATI O N This work was funded by Natural Science Foundation of China (Grant No.81701929), Natural Science Foundation of Guangdong Province (Grant No.2019A1515012170), and Guangdong Medical Research Foundation (Grant No.C2019112).