Minimal shedding of the glycocalyx layer during abdominal hysterectomy

Background: Surgery with and without hypervolaemia may cause shedding (breakdown) of the endothelial glycocalyx layer, but the severity of this problem is unclear. Methods: In this preliminary report of a larger clinical trial, the plasma and urine concentrations of three biomarkers of glycocalyx shedding (syndecan-1, hyaluronic acid and heparan sulfate) were measured in seven patients before, during, and after open hysterectomy. The fluid therapy consisted of 25ml/kg (approximately 2l) of Ringer's lactate, which was infused over 30min when the surgery started. The resulting plasma volume expansion at the end of the infusion was estimated from the haemodilution. Results: The mean plasma concentration of syndecan-1 was 21.7ng/ml before surgery and averaged 19.7ng/ml during and after the surgery. The plasma concentration of hyaluronic acid decreased from 38.0 to 27.7ng/ml (P<0.05), while heparan sulfate increased from 3.4 to 5.5μg/ml (P<0.05). The urine concentrations of syndecan-1 decreased significantly, while they increased for hyaluronic acid and heparan sulfate. Despite the vigorous fluid load, the urine flow did not exceed 1ml/min. Conclusions: No clear evidence was found for shedding of the endothelial glycocalyx layer when 2l of Ringer's lactate was infused over 30min during abdominal hysterectomy. Urine analyses yielded patterns of changes that differed from those in plasma. Trial registration:ISRCTN81005631. Registered May 17, 2016.