The Role of Anastomotic Vessels in Controlling Tissue Viability and Defining Tissue Necrosis with Special Reference to Complications Following Injection of Hyaluronic Acid Fillers

BACKGROUND: Most target areas for facial volumization procedures relate to the anatomical location of the facial or ophthalmic artery. Occasionally, inadvertent injection of hyaluronic acid (HA) filler into the arterial circulation occurs, and unrecognised, is irreparably associated with disastrous vascular complications. Of note, the site of complications, irrespective of the injection site, is similar, and falls into only 5 areas of the face, all within the functional angiosome of the facial or ophthalmic artery. MATERIAL AND METHODS: Retrospective and prospective studies were made to assess the site and behaviour of anastomotic vessels connecting the angiosomes of the face and their possible involvement in the pathogenesis of tissue necrosis. In-vivo studies of pig and rabbit, and archival human total body and prospective selective lead oxide injections of the head and neck were analysed. Results were compared with documented patterns of necrosis following inadvertent HA intra-arterial injection. RESULTS: Studies showed the location of TRUE and CHOKE anastomoses connecting the facial artery with neighbouring angiosomes predicted the tissue at risk of necrosis following inadvertent intra-arterial HA injection. CONCLUSION: Complications related to HA injections are intimately associated with: (i) the anatomical distribution of TRUE and CHOKE anastomoses connecting the facial artery to neighbouring ophthalmic and maxillary angiosomes where CHOKE vessels define the boundary of necrosis of an involved artery but TRUE anastomoses allow free passage to a remote site; or possibly (ii) retrograde perfusion of HA into avalvular facial veins, especially in the periorbital region, and thereby the ophthalmic vein, cavernous sinus and brain. ** Joint first authors * Presented at 50 Years of Aesthetics, American Society of Aesthetic Plastic Surgeons (ASAPS ), San Diego California Meeting, 27 April – 2 May 2017. Financial Disclosure: The authors have no financial interest to declare in relation to the content of this article. Acknowledgments: We would like to thank Mrs Prue Dodwell for her help with preparing the manuscript and images. Thanks also to Dr Adam Gascoigne for assistance with the dissections and Dr Louie Ye for his time with the Literature Review. The work would not have been possible without support from Mr Jim Carroll and The Donald Ratcliffe and Phyllis Macleod Trust. Corresponding Author: Professor Ian Taylor, Taylor-Lab, Department of Anatomy and Neurosciences, University of Melbourne, Parkville, Victoria 3052, Email: g.taylor@unimelb.edu.au ©2018American Society of Plastic Surgeons