Feasibility of obtaining endothelial cells from major surgery and critically ill patients

<b></b> <i>Background:</i> Endothelial cell biopsy (ECBx) is a promising tool to obtain endothelial cells (EC) for research purposes from a range of patients, however the minimally invasive procedure has not been described in the critically ill. Our study set out to demonstrate the feasibility of performing ECBx using discarded guidewires used as part of standard care (SOC). <i>Patients and methods:</i> Guidewires from central venous catheters (CVC) and arterial lines were collected from surgical patients prior to major surgery (n = 16) and from patients upon admission to the Intensive Care Unit (ICU) (n = 16). In surgical patients, additional ECBx were performed from cubital veins. Quantification and characterization of EC was performed using flow cytometry. <i>Results:</i> A total of 44 wires were collected with a similar yield of EC from standard of care CVC (2,265 IQR881-6,610 /wire, n = 20) and arterial lines (2,109 IQR 1,288-2,682 /wire, n = 13), and purposely performed cubital veins biopsies (2,089 905-3,636 /wire, n = 11; p = .83). Comparison of the phenotype of EC between cohorts showed a significant increase in size (p = .01) and internal complexity (p < .01) of cells in the ICU cohort compared to the surgical cohort. <i>Conclusions</i>: It is feasible to collect EC from discarded guidewires used in SOC. The data demonstrate phenotypic differences between EC between cohorts and that ECBx is a safe and well tolerated technique. Our findings suggest that ECBx can provide valuable insights into clinically relevant EC pathophysiology and may help guide future research.