ACell, a Current Review of Applications in Hair Transplant Surgery
I’m issuing this response because I am beginning to get phone calls requesting treatment with plucked hairs that are tainted with ACell based on presentations by Dr. Jerry Cooley and Dr. Gary Hitzig along with irrational exuberance on the part of some physicians who incorrectly feel these presentations represent a clinical breakthrough in the treatment of hair loss.
My Use of ACell
I first looked at ACell in the spring of 2007. In June of 2007, I began to research it in terms of treating horses for their lacerations since I own several horses. Horses are somewhat hirsute critters sort of like mice. Mice seem to grow hair when you apply butter. While ACell can regrow hair in horse wounds, it may simply be their predisposition to hair growth in general that is a work. I waited until ACell became FDA approved prior to considering it for use in humans.
I will begin by relaying my experience with ACell and then discuss the presentations of Dr. Cooley. When I began using ACell, I really did not expect much other than improved donor extraction site healing. Obviously, I knew there was a potential for regeneration of extracted follicles, but since only the ectodermal stem cells would be residual in the donor area, I did not consider them to have a enough regenerative capacity by themselves. I started to apply it into extraction sites from FUE. The greatest challenge was how to deliver the product. The product originally came in two versions that were FDA approved for use in humans. One was a thin sheet and the other was a cluster of tiny particle that poses attractive electrostatic charge to one another and most any other object they come in contact with as described by Coulomb’s law. More recently Acell offered a fine powder. The real challenge was how to get the small particles into extraction sites because the particles have a good bit of static electricity on them as previously described. This makes them somewhat sticky to the jeweler forceps, one another, hair, or anything else in the universe. Subsequently, I began cutting the thin sheets into small pieces and putting a small piece in as many extraction sites as possible. The greatest difficulty was noting which extraction sites had already been treated because you have to constantly look away to pick up another piece of ACell and it is often difficult to see the small pieces once you have placed them in the extraction sites. I’m quite sure that many sites were not treated as a result of this difficulty. Similarly, many sites were most likely treated more than once. Suffice it to say that I did the best I could given such a challenge. Later, I began mixing the small particles in a hyaluronic acid gel and forcing a small drop of the gel mixture into the extraction sites from a 1 cc syringe and an 18 or 19 gauge needle that I ground the sharp tip off of. When the fine powder became available, I switched to using this in the hyaluronic acid gel. The fine particles were a major breakthrough in terms of delivery. I found the ideal mixture was 60 mg of powder in 2 cc of the hyaluronic acid gel or 30 mg per cc of hyaluronic gel. One cc will usually treat well over 800 extraction sites. I often pre-treat the extraction sites with PRP and then drop the gel into the extraction sites. Once again treating a non-shaven donor area with ACell particles is very difficult due to static electricity. The particles want are attracted to the hair, as well as the jewelers forceps. The gel mixture facilitates the delivery of ACell to these tiny individual extraction sites. One question that remains is whether ACell will become active once the gel sets up and “hardens”. The premise is that the hyaluronic acid will be degraded and leave the ACell to do its job. Will the hyaluronic acid degrade fast enough for the ACell to be affective? I tried mixing the ACell in PRP, but it just clumped and was impossible to administer to my extraction sites. Thus, the optimal option to date is the Acell/hyaluronic gel suspension at this point. Currently, I am working on a superior suspension of Acell in hyaluronic acid, as well as a better delivery method.
I also began mixing 30 mg of the tiny particles in 30 cc of normal saline and injecting this into the recipient areas to include donor scars. I often treat these areas with PRP and microneedling, as well. I then activate the PRP by making incisions in the scalp or by injecting the patient’s thrombin or bovine thrombin into the recipient areas as taught by Joe Greco, PA, PhD. I have often added the ACell ECM to areas treated with PRP without grafts as Joe Greco has noted an improvement of pre-existing hair coverage in up to 70% of individual treated with a combination of ECM and PRP without grafting. I have noted the same in some of my patients, but follow up is difficult due to the distance between my clinic and the homes of my patients. Joe Greco has his own proprietary ECM that he obtains from the patient. Joe Greco has not released this ECM to other physicians yet. Joe is a wealth of knowledge and research with regard to PRP and eager to share this information.
I often add ACell particles to my grafts by placing 25 grafts at a time in a ring cup that we hold on our finger during placement of the grafts along with particles of Acell in the cup. This way the grafts are directly exposed to Acell and many pick up a few particles during storage in the ring cup due to attractive electrostatic forces. The hope is that such exposure and tainting will improve survival of transected hair and possibly improve the survival of the grafted hair in general. We have not seen any documented benefit of this procedure yet, but we are still evaluating it.
What I’ve noted so far is that ACell has the capacity to eliminate hypopigmented spotting in some FUE extraction sites. Those extraction sites that remained hypopigmented might not have responded or we might not have treated them with ACell. Again, it is impossible to know if all the sites are treated with ACell when you are using the powder or the cut up pieces of Acell. This is why I more recently began working with a gel because it is much easier to administer he gel suspension and it is far easier to verify that we have treated all the extraction sites. Acell also may have the ability to induce hair regrowth in some FUE extraction sites. I did not expect this to occur, but we were able to achieve some regeneration. For example, in a patient who had over 2000 grafts extracted, the number of hypopigmented spots were significantly fewer than the number of extractions, many extraction sites exhibited normal skin tone, and there were not as many empty extraction sites as one would expect following over 2000 extractions. In other words healing was better and some evidence of follicle regeneration was exhibited. Not all patients exhibit hypopigmentation with FUE, but those that do generally have hypopigmentation in all the extraction sites. The presence of both hypopigmented extraction sites and normal skin tone extraction sites suggests, but does not confirm, that Acell played a hand in improving the appearance of many extraction sites. Based on my experience in FUE, I also noted far fewer empty extraction sites than I would have expected following extraction of over 2000 grafts. This suggested, but did not confirm, that Acell may play a role in regeneration of hair follicles in extraction sites. I have also noted in other examples that an injection of a PRP and ACell combination can induce improvement in coverage of native hairs affected by androgenic alopecia in the absence of grafting. We also often treat these native areas with microneedeling and add thrombin to help activate the platelets in the PRP in areas of native hair that are not grafted. Again this practice has improved coverage in some, but we do not have statistically significant data to support our findings yet. A study in Korea showed that the PRP treated side resulted in faster graft growth than the untreated side of the grafted recipient area. Though I have not specifically evaluated this Korean finding, I have not seen confirmation of this Korean PRP study in my anecdotal evaluations.
As another example I had one patient who underwent a large session of body hair transplantation. He had excellent growth of his beard hair, but his chest hair did not grow well. In a follow up procedure, I treated his donor scars with chest hair, but this time injected the scars with ACell/Saline 1mg/cc and PRP. The chest hairs grew well this time and grew faster than areas treated with PRP alone with chest hair as well as beard hair. Did the Acell, PRP injections promote a better yield of body hair and did they promote faster regrowth of the body hair? This is yet another question that needs to be answered.