Modifying the vessel walls in porcine kidneys during machine perfusion

Background Endothelial glycocalyx regulates the endothelial function and plays an active role in maintaining vascular homeostasis. During ischema and reperfusion, the glycocalyx is rapidly shed into the blood stream. A Corline heparin conjugate (CHC; Corline systems AB, Uppsala, Sweden) consists of 70 heparin molecules that have the capacity to adhere strongly to biological tissues expressing heparin affinity. We hypothesized that CHC could be used to restore disrupted glycocalyx in vivo in kidneys from brain-dead pigs. Materials and methods Brain death was induced in male landrace pigs (n = 6) by inflating a balloon catheter in the epidural space until obtaining negative cerebral perfusion. The recovered kidneys (n = 5 + 5) were perfused by hypothermic machine perfusion using two Lifeport kidney transporters (Organ Recovery Systems, Chicago, IL). CHC (50 mg) (including 25 mg biotinylated CHC) or 50 mg unfractionated heparin (control) was added to the perfusion fluid in the respective machines. In one case, the kidneys were used only for dose escalation of CHC with the same procedure. Results CHC was detected by immunofluorescence and confocal microscopy in the inner surface of the vessel walls. The binding of CHC in the kidney was confirmed indirectly by consumption of CHC from the perfusion fluid. Conclusions In this first attempt, we show that CHC maybe used to coat the vessel walls of perfused kidneys during hypothermic machine perfusion, an approach that could become useful in restoring endothelial glycocalyx of kidneys recovered from deceased donors to protect vascular endothelium and possibly ameliorate ischemia and reperfusion injuries.