Differences in hub and spoke vascular units practice during the novel Coronavirus-19 (COVID-19) outbreak in Lombardy, Italy

BACKGROUND: To highlight clinical practice among referral (Hub, HH) or satellite (Spoke, SH) hospitals Vascular Surgery Units (VSUs) in Lombardy, during the COVID-19 pandemic "phase 1" period (March 8 - May 3, 2020). METHODS: The Vascular Surgery Group of Regione Lombardia Register, a real-word, multicenter, retrospective register was interrogated. All patients admitted with vascular disease were included. Patients' data on demographics, COVID-19 positivity, comorbidities and outcomes were extrapolated. Two cohorts were obtained: patients admitted to HH or SH. Primary endpoint was 30- day mortality rate. Secondary outcomes were 30-day complications and amputation (in case of peripheral artery disease [PAD]) rates. Univariate and multivariate analysis were used to compare HH and SH groups and predictors of poor outcomes. RESULTS: During the study period, 659 vascular patients in 4 HH and 27 SH were analyzed. Among these, 321 (48.7%) were admitted to a HH. No difference in COVID-19 positive patients was described (21.7% in HH vs 15.9% in SH; p=.058). After 30 days from intervention, HH and SH experienced similar mortality and no-intervention-related complication rate (12.1% vs 10.0%; p=.427 and 10.3% vs 8.3%; p=.377, respectively). Conversely, in HH postoperative complications were higher (23.4% vs 16.9%, p=.038) and amputations in patients treated for PAD were lower (10.8% vs 26.8%; p