Abstract

Post-surgical Systemic Vascular Stress Response (SVVR) is more than a BP, CO or circulating volume response. Breakdown of the endothelial glycocalyx at the blood-vessel interface can result in endothelial activation, elevated permeability, adhesion of leukocytes, coagulation disturbance, and development of heterogeneous microvascular flow—all transforming inflammatory, haemodynamic, oxidative and ischaemia-reperfusion signals. This is a narrative review of the evidence for glycocalyx injury in major surgical contexts, looking at the development of capillary leak, tissue oedema, microcirculatory failure and postoperative organ dysfunction. Special focus is placed on haemorrhage, cardiopulmonary bypass, inflammatory activation, ischaemia-reperfusion, transfusion, fluid loading and vasopressor exposure. Preclinical investigations show that biomarkers, such as syndecan-1, heparan sulfate and hyaluronan are all elevated during the peri-operative period and are associated with changes in sublingual microvascular perfusion. Elevation of the biomarkers is not, however, equivalent to actual loss of the glycocalyx at the tissue level, and a bedside gold standard for assessment of the glycocalyx integrity does not exist. Current evidence thus favors a vascular-protective approach to the periop period, instead of a one-and-done glycocalyx-repair approach. Future studies should include endothelial markers, direct microcirculatory imaging, haemodynamic phenotyping, and organ-pathology outcome measurements.

Keywords: Endothelial dysfunction, Clycocalxy injury, Capillary leak, Organ pathology