Diluted subdermal injections of calcium hydroxylapatite (CaHA, Radiesse, Merz Pharmaceuticals) improve skin quality on the face, neck, chest, arms, abdomen, legs and buttocks, according to a global panel of aesthetic physicians who developed best practice recommendations for CaHA use.
Limited studies suggest CaHA tightens skin and improves superficial wrinkles, skin elasticity and thickness by promoting by stimulating collagen and elastin, according to the paper published November 2018 in Dermatologic Surgery.
The guideline addresses the diluted, or 1:1 ratio of CaHA reconstituted with lidocaine or saline, and hyper-dilution referring to reconstitution using ratios of 1:2 or higher.
For over a decade, doctors have used CaHA to safely rejuvenate faces, first for HIV-associated lipoatrophy, second for moderate to severe facial wrinkles and folds such as nasolabial folds and finallyf for the dorsal hands. These FDA-approved indications all involve mixing a 1.5 mL syringe CaHA with 0.3 mL lidocaine to create a product appropriate for lift and volume. However, doctors are increasingly using more highly diluted injections of CaHA off-label with the primary goal of biostimulation rather than volumization, guideline author Heidi A. Waldorf, M.D., a dermatologist in Nanuet, N.Y., tells The Aesthetic Channel.
“What came out in the international consensus conference was that all of us independently had been mixing CaHA with lidocaine and/or saline in off-label protocols to harness its known biostimulatory effect on skin on the face and body. As a group, we combined both our own experiences with published case series by members to develop protocols that can be easily followed by physicians in their own offices,” Dr. Waldorf says. “What is novel about this approach is the duality of CaHA as an injectable product. It can be used to add volume but also, in dilute or hyper-dilute form, as a biostimulator to improve the tone and texture and even tighten skin.”
Among Radiesse Recommendations
When treating the face, doctors should place diluted CaHA in the immediate subdermal plan and fan it across the cheeks and jawline.
Doctors should consider using cannulas and dilution ratios of 1:2 to 1:4 when injecting the neck to reduce the risk of injecting too superficially, which could result in product visibility and nodules.
Two syringes of diluted 1:2 CaHA, for a total of 9 mL solution, can improve skin crepiness and laxity in the upper arms of patients — ideally younger than 50 years.
Based on largely personal experience because the off-label use of diluted and hyper-diluted CaHA in the abdomen, buttocks and legs is newer, the panel suggests doctors use CaHA to treat:
- Age-related elastosis and postinterventional restoration to increase dermal thickness and correct irregularities of the abdomen
- Gluteal sagging and skin contour irregularities, such as cellulite and striae, on the buttocks
- Skin flaccidity to improve skin quality in patients with mild skin irregularities on the anterior and posterior thigh and just above the knee
Dr. Waldorf says she uses dilute and hyper-diluted CaHA most often for the lateral cheeks and neck.
“I also use in the upper arms and have used it for areas of cellulite on the buttocks,” she says. “I think of it acting like a liquid ‘mesh’ of sorts. It provides some immediate soft structural support and then more persistent improvement in the tightness and overall appearance of the skin.”
Dr. Waldorf notes that while CaHA has the FDA indication for volume improvement of the hands, she uses a 1:1 dilution instead of just the small amount of lidocaine used on label.
“I believe that is one reason that the results are longer lasting than one might expect from the volume aspect alone,” Dr. Waldorf says.
Dr. Waldorf does not use CaHA in the lips, tear troughs or eyelids.
Dr. Waldorf’s has several best practices to offer, including:
That doctors avoid mixing the product in advance.
“It will inject most smoothly through a needle or cannula if you mix it immediately before injection,” she says. “If I know that I am going to use a full syringe for biostimulation, I start with regular Radiesse and add a small amount of lidocaine with epinephrine (0.1 cc – 0.3 cc) and make up the rest of the diluent with saline.”
When she wants to combine volumization and biostimulation but doesn’t feel she needs the full syringe for either, Dr. Waldorf will use Radiesse (+) and add saline to what is remaining in the syringe.
“When using hyper-diluted CaHA, remember less is more. I let patients know that I will be adding over time. For example, for the neck, I will often use 1 syringe of CaHA and then ask the patient to return in 2 to 4 weeks for another treatment. The patient has less swelling that way, which is especially important when using higher dilutions. When using the product for biostimulation, be aware that the ideal plane of injection is generally higher than used for volumization,” she says.
The authors write that CaHA treatment can be used as an adjunct to volume augmentation or combined with other modalities for optimal results.
Dr. Waldorf says she often uses CaHA in conjunction with skin tightening using ultrasound or radiofrequency and with fractionated resurfacing.
“Frankly, the improved skin quality after CaHA injection improves the results for all of those modalities,” she says.
In addition to minor adverse events, including injection-site erythema and noninflammatory nodule formation, CaHA injection rarely results in blood vessel occlusion, the panel reports.
The report offers preliminary guidelines for the off-label use of CaHA on the face and body. Future rigorous clinical trials will provide more evidence for optimal outcomes, the authors write.