injectors, its use does not represent a risk or bring consequences to thyroid physiology, but its possible interference in the evaluation of pathologies was questioned. It is also important to remember that no minimally invasive procedure is risk-free, and in the hands of inexperienced injectors, the injury of deep structures of the neck, and the deposition of the product in the wrong plane is one of the major concerns.
It is known that calcium hydroxyapatite presents a hyperechogenic characteristic with posterior acoustic shadowing at the ultrasound examination.3,10,11 Most published studies evaluated an application of hydroxyapatite, without dilutions, and, in most cases, used as a filler. The neck, characteristically, presents one of the thinnest skins of the body and for greater safety of the treatment, an intermediary dilution is necessary.4,5 The standardization of the body treatment by vectorized figures in a dilution of 1:4 was published by the author and this has been a referral to improving the rationalization of the treatment.6
So far medical literature lacks an ultrasonographic evaluation of hyperdiluted calcium hydroxyapatite form and particularly, if this technique can negatively impact the assessment of noble structures underlying the application plane, such as the thyroid in cervical treatment.
Our findings show that despite being hyperdiluted, the hydroxyapatite keeps its heterogenicity, also generating the posterior acoustic shadowing artifact. When the thyroid is evaluated after recently receiving the injection, for instance, 15- days later, experienced radiologists can recognize the product and, even though there is some degree of difficulty in the thyroid assessment, there is no negative impact in the final assessment. Posterior analyses, such as 60 days after the injection, still allows the identification of the product, but the possible artifacts do not impair on the evaluation of the thyroid, characterizing a gradual reduction of the artifact over time, with no impairment on the glandular assessment (Figure 7).
According to the radiologists who participated in the study, the product could not be identified by the radiologists who were not specialists in dermatological ultrasound and/or professionals who did not know that a previous treatment was performed and did not conduct the so called 'active seeking'.
Although a small number of patients were treated in this study (n=10), this was a prospective and controlled study with radiologists blinded to the groups, therefore, providing reliability to these findings. Studies such as this one can shed light on other questionable approaches, which can be potentially interesting, for example, for the treatment of saggy breasts with injectable biostimulators.
It is known that calcium hydroxyapatite presents a hyperechogenic characteristic with posterior acoustic shadowing at the ultrasound examination.3,10,11 Most published studies evaluated an application of hydroxyapatite, without dilutions, and, in most cases, used as a filler. The neck, characteristically, presents one of the thinnest skins of the body and for greater safety of the treatment, an intermediary dilution is necessary.4,5 The standardization of the body treatment by vectorized figures in a dilution of 1:4 was published by the author and this has been a referral to improving the rationalization of the treatment.6
So far medical literature lacks an ultrasonographic evaluation of hyperdiluted calcium hydroxyapatite form and particularly, if this technique can negatively impact the assessment of noble structures underlying the application plane, such as the thyroid in cervical treatment.
Our findings show that despite being hyperdiluted, the hydroxyapatite keeps its heterogenicity, also generating the posterior acoustic shadowing artifact. When the thyroid is evaluated after recently receiving the injection, for instance, 15- days later, experienced radiologists can recognize the product and, even though there is some degree of difficulty in the thyroid assessment, there is no negative impact in the final assessment. Posterior analyses, such as 60 days after the injection, still allows the identification of the product, but the possible artifacts do not impair on the evaluation of the thyroid, characterizing a gradual reduction of the artifact over time, with no impairment on the glandular assessment (Figure 7).
According to the radiologists who participated in the study, the product could not be identified by the radiologists who were not specialists in dermatological ultrasound and/or professionals who did not know that a previous treatment was performed and did not conduct the so called 'active seeking'.
Although a small number of patients were treated in this study (n=10), this was a prospective and controlled study with radiologists blinded to the groups, therefore, providing reliability to these findings. Studies such as this one can shed light on other questionable approaches, which can be potentially interesting, for example, for the treatment of saggy breasts with injectable biostimulators.
CONCLUSION
Based on the findings of this study, we concluded that calcium hydroxyapatite applied in the hyperdiluted form of 1:4 for the neck rejuvenation has little interference and does not impair the assessment of the thyroid in just 15 days after the injection. After 60 days from injection, although it is still possible to identify the product by ultrasonography, its artifacts do not impair the underlying thyroid assessment by any means. It is understood, therefore, that given the concern of imaging followup of the thyroid with ultrasound, the calcium hydroxyapatite, in a hyperdiluted form, is proved to be a safe product for the treatment of the cervical region.
DISCLOSURES
The author is a Brazilian speaker for the company Merz Aesthetics, one of the manufacturers of calcium hydroxyapatite (Radiesse®). For this study, the author declares no conflict of interest.
REFERENCES
1. Vanaman M, Fabi SG, Cox SE. Neck rejuvenation using a combination approach: our experience and a review of the literature. Dermatologic Surgery. 2016;42(suppl 2):S94-S100.. doi: 10.1097/DSS.0000000000000699.
2. Yutskovskaya YA, Kogan EA. Improved neocollagenesis and skin mechanical properties after injection of diluted calcium hydroxylapatite in the neck and décolletage: a pilot study. J Drugs Dermatol. 2017;16(1):68-74.
3. Wortsman X, Wortsman J. Sonographic outcomes of cosmetic procedures. Am J Roentgenol. 2011;197(5):W910-W918. doi: 10.2214/AJR.11.6719.
4. Goldie K, Peeters W, Alghoul M, et al. Global consensus guidelines for the injection of diluted and hyperdiluted calcium hydroxylapatite for skin tightening. Dermatol Surg. 2018;44(1):S32-S41. doi: 10.1097/ DSS.0000000000001685.
5. de Almeida AT, Figueredo V, da Cunha ALG, et al. Consensus recommendations for the use of hyperdiluted calcium hydroxyapatite (Radiesse) as a face and body biostimulatory agent: Plast Reconstr Surg - Glob Open. 2019;7(3):e2160. doi: 10.1097/GOX.0000000000002160.
6. Faria GEL, Santos DB, Tartare A, Bento AM, Boggio RF. Standardization of the body vectoring technique with calcium hydroxyapatite. Surg Cosmet Dermatol. 2020;12 (44);118-120. doi: 10.5935/scd1984-8773.20201243771.
7. Kadouch, JA. Calcium hydroxylapatite: a review on safety and complications. J Cos Dermatol. 2017;16(2):152-161. doi: 10.1111/jocd.12326.
8. Wasylkowski VC. Body vectoring technique with Radiesse® for tightening of the abdomen, thighs, and brachial zone. Clin Cosmet Investig Dermatol. 2015;8:267-273. doi:10.2147/CCID.S75631.
9. Shah A, Cunha B. Anatomy, Head and Neck, Anterior Cervical Region. In: StatPearls [Internet]. Updated July 31, 2020. Treasure Island (FL): StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK557475/#_NBK557475_ pubdet_
10. DÃaz CPG. High resolution ultrasound of soft tissues for characterization of fillers and its complications. Revista Colombiana de Radiologica. 2019;30: 5064-5068.
11. Grippaudo FR, Mattei M. Highâ€frequency sonography of temporary and permanent dermal fillers. Skin Research and Technology. 2010;16(3): 265- 269. doi: 10.1111/j.1600-0846.2010.00428.
2. Yutskovskaya YA, Kogan EA. Improved neocollagenesis and skin mechanical properties after injection of diluted calcium hydroxylapatite in the neck and décolletage: a pilot study. J Drugs Dermatol. 2017;16(1):68-74.
3. Wortsman X, Wortsman J. Sonographic outcomes of cosmetic procedures. Am J Roentgenol. 2011;197(5):W910-W918. doi: 10.2214/AJR.11.6719.
4. Goldie K, Peeters W, Alghoul M, et al. Global consensus guidelines for the injection of diluted and hyperdiluted calcium hydroxylapatite for skin tightening. Dermatol Surg. 2018;44(1):S32-S41. doi: 10.1097/ DSS.0000000000001685.
5. de Almeida AT, Figueredo V, da Cunha ALG, et al. Consensus recommendations for the use of hyperdiluted calcium hydroxyapatite (Radiesse) as a face and body biostimulatory agent: Plast Reconstr Surg - Glob Open. 2019;7(3):e2160. doi: 10.1097/GOX.0000000000002160.
6. Faria GEL, Santos DB, Tartare A, Bento AM, Boggio RF. Standardization of the body vectoring technique with calcium hydroxyapatite. Surg Cosmet Dermatol. 2020;12 (44);118-120. doi: 10.5935/scd1984-8773.20201243771.
7. Kadouch, JA. Calcium hydroxylapatite: a review on safety and complications. J Cos Dermatol. 2017;16(2):152-161. doi: 10.1111/jocd.12326.
8. Wasylkowski VC. Body vectoring technique with Radiesse® for tightening of the abdomen, thighs, and brachial zone. Clin Cosmet Investig Dermatol. 2015;8:267-273. doi:10.2147/CCID.S75631.
9. Shah A, Cunha B. Anatomy, Head and Neck, Anterior Cervical Region. In: StatPearls [Internet]. Updated July 31, 2020. Treasure Island (FL): StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK557475/#_NBK557475_ pubdet_
10. DÃaz CPG. High resolution ultrasound of soft tissues for characterization of fillers and its complications. Revista Colombiana de Radiologica. 2019;30: 5064-5068.
11. Grippaudo FR, Mattei M. Highâ€frequency sonography of temporary and permanent dermal fillers. Skin Research and Technology. 2010;16(3): 265- 269. doi: 10.1111/j.1600-0846.2010.00428.
AUTHOR CORRESPONDENCE
Gladstone Faria MD gladstonefaria@hotmail.com
