The Anatomy behind Adverse Events in Hand Volumizing Procedures: Retrospective Evaluations of 11 Years of Experience

Background: To retrospectively evaluate the rate of adverse events after hand volumizing procedures using a calcium hydroxylapatite product and to investigate the relationship between injector used (i.e., needle versus cannula) and technique applied (i.e., bolus, tenting, proximal-to-distal fanning, distal-toproximal single line). Methods: Two hundred twenty individuals, including 214 women (97.3 percent) aged 52.3 +/- 11.4 years, treated bilaterally for hand rejuvenation were investigated between the years 2006 and 2017. Cadaveric dissections (n = 12), fluoroscopic (n = 4), ultrasound (n = 22), and computed tomographic (n = 4) imaging were also performed to guide conclusions. Results: Thirty-two of 440 hands (7.3 percent) developed adverse events within the first 15 days, with swelling in 11 (5 percent), pain in four (1.8 percent), erythema in three (1.4 percent), and discoloration in one (0.5 percent). Using a needle (versus a cannula) was significantly related to the occurrence of adverse events (OR, 7.57; 95 percent CI, 3.76 to 15.24; p < 0.001). The proximalto- distal fanning technique with access to the dorsal superficial lamina was identified as a safer application technique, with each of the other techniques having a significantly increased odds ratio for adverse events: bolus technique (OR, 26.9; 95 percent CI, 6.87 to 105.2; p < 0.001), tenting technique (OR, 24.73; 95 percent CI, 7.48 to 81.76; p < 0.001), and single-line technique (OR, 26.68; 95 percent CI, 7.45 to 95.48; p < 0.001). Conclusions: The results of this study support the use of cannula versus needle and the proximal-to-distal fanning technique. The underlying anatomy supports the positioning of the material into the subdermal space, which can be identified less than 1 mm deep to the skin surface, and is termed the dorsal superficial lamina.