Novel Graft-Holding Solution Safe in Hair Transplantation

Graft viability and postsurgical shedding was improved with histidine-tryptophan-ketoglutarate solution with adenosine triphosphate and deferoxamine.

Graft viability is improved and postsurgical shedding is attenuated for hair transplantation with the use of the graft-holding histidine-tryptophan-ketoglutarate solution plus adenosine triphosphate and deferoxamine (HTK-AD), according to study findings published in Dermatologic Surgery.

Researchers conducted a randomized, double-blind, prospective, controlled clinical trial between September 2020 and June 2021. A total of 240 patients aged 18 to 60 years were randomly assigned in a 1:1 ratio to either the HTK-AD or Ringer solution (RS) groups. All participants were diagnosed with congenial high hairline or androgenetic alopecia without comorbid diabetes, heart disease, hypertension, or any dermatologic or psychiatric disorders. Mega-session hair transplantation was performed and patients underwent follow-up, with postoperative global photographs taken at 1, 3, and 9 months. Patients and outcome assessors were blinded to group assignments.

There were 118 participants in the HTK-AD group (19% women; 36% transplant graft ≥3000; graft density, 45 grafts/cm2; implantation time for ≥3000, 3.5 hours) and 119 patients in the RS group (25% women; 34% transplant graft ≥3000; graft density, 45 grafts/cm2; implantation time for ≥3000, 5.5 hours) who completed the 9-month follow-up and were included in final analysis. There were no significant baseline between-group differences (P <.001).

Hair follicles harvested from the occipital scalp by follicular unit extraction (FUE) were placed in either HTK-AD or in chilled Ringer solution (RS) to be subsequently implanted in recipients. Graft morphology and apoptosis levels were assessed with live or dead staining and Masson trichrome staining. Participants first reported postsurgical hair shedding, which was confirmed by a blinded dermatologist. Additionally, pretransplantation recipient zones were randomly marked in 5 areas, with each area being 1 cm2. During follow-up, a blinded dermatologist counted hair follicle numbers in these 5 areas using dermoscopy.

Findings therefore showed that HTK-AD is a safe preservation solution that can be used as a substitute for RS or saline solutions for isolated hair graft protection.

Organized dense collagen construction and higher cell viability were maintained by grafts in HTK-AD vs RS, which became soft and easily deformed after 4-hour preservation, negatively impacting implantation. Incidence of mega-session transplantation postsurgical hair shedding was reduced from 95.00% in RS solution to 73.81% with HTK-AD (P <.05). With at least 3000 grafts transplanted, maximum shedding percentage of RS (90%) was reduced in HTK-AD (85%; P <.001) and shedding onset delayed from RS (14 days) to HTK-AD (21 days; P <.001). Hair regrowth started earlier and shedding duration was abbreviated in HTK-AD vs RS (P <.05). Final graft survival rates of mega-session transplantation show no between-group difference (P =.112).

No participants reported dissatisfaction with their surgery, but greater satisfaction with recovery and surgical outcomes was reported by those in the HTK-AD group vs those in the RS group. No participants in either group experienced obvious infection, necrosis, or additional serious adverse effects. Postoperative erythema or folliculitis affected some participants.

Limitations of the study include unpublished data on oxidative stress damage detected during hair graft preservation.

“Histidine-tryptophan-ketoglutarate solution with adenosine triphosphate and deferoxamine is superior to RS for hair graft preservation because it improves graft viability and alleviates postsurgical shedding,” the researchers conclude. “Findings therefore showed that HTK-AD is a safe preservation solution that can be used as a substitute for RS or saline solutions for isolated hair graft protection.”


Zhou Y, Zhang J, Fan Z, Hu Z, Miao Y. Evaluation of a novel graft-holding solution in hair transplantation: a randomized controlled clinical study. Dermatol Surg. Published online April 7, 2023. doi:10.1097/DSS.0000000000003799