DHI (Direct Hair Implant)

Main article: Hair transplant

There is little difference between the DHI (Direct Hair Implant) and FUE (Follicular Unit Extraction) methods, as FUE is the foundation for DHI hair transplantation when hair follicles are removed from the donor area. The removed grafts will be immediately sorted and prepared for the movement process. Each DHI pen will then be filled with hair follicles to make incisions and move the grafts to the baldness area. Hair follicles extracted by the DHI method are without blood supply for a significantly shorter time than other transplant methods.

Cost-effectiveness for clinics

Clinics and doctors supporting DHI often promise the most natural and successful results with hair transplantation, carried out using a direct hair transplant technique. According to them, DHI allows full control over the direction of growth, implies the shortest recovery time, higher density and, above all, the highest growing profitability in the business. All that should be achieved by this method is the direct movement of the extracted hair follicles from the donor region to the recipient (hair placement zone) and ensuring blood supply as quickly as possible.

As with the Follow-up Unit Extraction (FUE) method, hair follicles (grafts) will be separately extracted from the donor region of the patient (direct hair implantation) and allow the extracted grafts to be immediately moved to the baldness region. That is why a number of promises made with DHI are mainly related to the FUE process. In terms of the extraction process, many physicians use micromotors or other motorized devices offered by numerous brands to increase workload, avoid fatigue, and save time. In many clinics, micromotors are also used to compensate for the lack of practical experience and personal skills of trichological surgeons.

Thus, clinics and trichologists performing DHI hair transplants are among a number of pros during the extraction process performed by FUE (Follicular Unit Extraction) to be "ahead" of outdated methods such as the FUT method.

What is the procedure for direct hair transplantation (DHI)

The DHI method involves separating hair follicles after extraction to fill several small implants. DHI pen, also called CHOI Implanter.

DHI Hair Transplant Tool

It has a plunger device and a thin hollow needle at the tip to prepare incisions and simultaneously place transplants on the recipient's site. All the innovation that is presented in the DHI method is part of a regular procedure that combines the extraction process with graft implantation.

Advantages and disadvantages of the DHI method

Discomfort and stress for patient and surgeon

Patients who decide on a DHI hair transplant will be subjected to discomfort and increased stress as a result of the fact that several areas of his head will be under medical supervision at once. Local anesthesia will be necessary for both parts of the head at the same time. To immediately/simultaneously move hair follicles to the landing area, the surgeon-trichologist must instantly switch from the extraction process to the movement process. This is why in many clinics medical assistants are often involved in the transplant process, and are not always great professionals in their field.

In the event that physicians simultaneously perform the graft extraction and planting process, the number of transplantable grafts during the daily procedure may be significantly lower than with the FUE hair transplantation method. The DHI method is extremely time-consuming and stressful for a trichologist surgeon, which can lead to significant workload.

Those with enough experience and individual skills to successfully perform manual hair transplants will soon notice the limits of the daily workload. This is why most clinics practicing DHI use a micromotor for the extraction process to increase the rate of extraction of grafts. In addition, doctors will have to rely on expanded medical staff to accurately perform hair follicle implantation, resulting in increased costs for the patient.

Graft engraftability

Based on the latest scientific studies (FUE Europe), as of 2022 there is no definitive evidence that transplants extracted from a patient's donor area may deteriorate if hair follicles are properly preserved according to medical standards for their transplantation. In most cases, it is an extraction process and the chosen method is responsible for higher or lower numbers of grafts in hair transplants.

This is why there is no medical need for a method for performing extraction and implantation simultaneously when using DHI Implanter. Blood supply to human transplants will be sufficiently guaranteed with regular FUE hair transplants and with the procedure performed in stages with fewer vaccinations. Once 500 or 800 grafts have been successfully removed from the donor area, the trichologist surgeon will be able to begin the movement process and follow this procedure to the end, concentrating on a single task.

DHI graft disorder

Hair follicles can be damaged during use by a DHI pen surgeon (Choi-Implanter) if they are performed without much concentration, accuracy, and experience. This may also affect the final outcome and engraftment of the grafts. DHI needs years of experience and training.

Wound healing

If we compare both methods, then there is no particular difference in the timing of healing. It may seem rather absurd to argue that the use of Choi-Implanter (DHI-pen) may result in higher density or reduced patient recovery time. Because healing and regenerating multiple layers of skin is independent of using a pen instead of thin, precise scalpels, this is likely to be a successful marketing strategy that allows businesses to promote a DHI pen that is used only by a minority of trichologists.

Practical and years of experience, personal skills and trichologist skill have always been the cornerstone of success to ensure outstanding results in hair transplantation. The final outcome of the transplant cannot be influenced by the use of a graft insertion pen directly into the baldness area.

A large number of recognized trichologists in this business still continue to prepare incisions through the lateral slit or hollow needles without the need for DHI implantation to simultaneously implant transplants, as this can cause stress and damage when handling follicles. As for scarring, as of 2022 there is no valid evidence that the use of Choi-Implanter can lead to less visible or invisible scarring.

Direction and angle of hair growth

Both the direction and the angle of growth of the grafts will necessarily depend on the exact placement of the hair follicles. Unnatural manifestations and poor outcomes were generally reported by physicians with low or no experience and with numerous low-cost transplant tool providers. There is doubt that devices such as the DHI implant can help prevent deplorable outcomes because it can attract more unqualified doctors to perform hair transplants with an implanted pen without the necessary experience or skills. Many years of experience and practical skills are mandatory requirements for achieving natural and aesthetic results of hair transplantation.

At the moment, only a small number (less than 10%) of noted trichological surgeons practice the DHI method using Choi-Implanter. Doctors using the DHI method need training and advanced training. Since there is no proven benefit from using a DHI pen when performing a hair transplant, this is only a marketing hype. A longer process, as well as more stress, are likely to lead to possible damage when extracting and planting grafts with DHI.