COVID and microsurgery: Did the microsurgical anastomosis failure rate in three hand surgery and orthoplastic units increase? A retrospective multicenter study

Introduction: COVID-19 infection seems to have among its fundamental pathogenetic mechanisms the appearance of a pro-thrombotic state capable of causing severe damage to various organs (lungs, kidneys, eyes …). Furthermore, the vaccines marketed in Italy in December 2020, used to slow the spread and mortality of this virus, also seem responsible for a possible pro-thrombotic state in the subjects to which they are inoculated. The authors of this work then wondered if the COVID-19 pandemic may have somehow altered the results of microsurgical anastomoses performed at their centers. Materials and methods: More than 270 patients who had at least one microsurgical vascular suture, in one of the three centers involved in this study, in the last four years were then retrospectively evaluated (two years pre-COVID vs. two years post-COVID). Planned surgeries of oncological, post-infection, or post-trauma) patients treated with microsurgical flap and patients who underwent digital or hand reimplantation were included. Failure rates were compared, taking into consideration whether patients had tested positive for COVID-19 or had a COVID-19 vaccine shot in the six months before the surgery. Results: The anastomosis success rate of the entire “pre-COVID” group is 70.4 %, while that of the “COVID” group is 73.3 %. Different subgroups are analyzed, and the only statistically significant difference in results is obtained by comparing the success rate of the “pre-COVID” group to the subgroup, in the COVID era, of patients who have tested positive for COVID or had at least one dose of vaccine. Conclusions: According to this study, failures of microsurgical anastomoses in patients previously affected by COVID or in previously vaccinated patients do not appear to have increased. On the contrary, COVID and/or vaccines might have a protective action.