title: Experimental in-vivo model of intravascular shunting for neurosurgical bypass.
abstract: BACKGROUND
  Excessively long clamping time and suboptimal position of stitches can influence the anastomosis patency and the clinical outcome in cerebral bypass surgery. Coronary intravascular micro-shunts could represent an innovative solution for neurosurgical bypass, but the hemodynamic properties of these devices should be extensively studied before their translational application. We created an experimental in-vivo model and we analyzed the blood flow and pressure modification induced by the micro-shunt.
  
  
  METHODS
  After laparotomy, an intravascular micro-shunt was placed into the aorta of 8 adult rats, simulating a neurosurgical setting in which the shunt is temporary placed inside the receiving cerebral vessel. A fiber-optic pressure sensor was placed in the femoral artery and the blood pressure continuously recorded during the procedure. Using an ultrasound vascular probe, blood flow velocity in aorta was measured at baseline and both proximally and distally to the shunt.
  
  
  RESULTS
  After shunt positioning, no significant decrease in blood pressure was observed (mean value 68.57 versus 80.00 mmHg; P=0.48). Distal aortic blood flow, expressed as peak systolic velocity, showed a significant decrease after shunt positioning (mean value 51.88 versus 86.88 cm/sec; P=0.04), with a mean residual blood flow of 63%. Blood flow values recorded immediately upstream to the shunt did not differ from baseline.
  
  
  CONCLUSIONS
  This is the first in-vivo experimental study concerning the hemodynamic properties of an intravascular micro-shunt. Our results demonstrate that this device provides a considerable blood out-flow without significant changes in blood pressure, suggesting that specific neurosurgical micro-shunts might be developed.
authors.affiliation: Laboratory of Experimental Stroke Research, Department of Surgery and Interdisciplinary Medicine (DCMT), University of Milano Bicocca, Monza, Italy - matteo.riva@unimi.it.
authors.forename: Matteo
authors.initials: M
authors.lastname: Riva
authors.affiliation: Laboratory of Experimental Stroke Research, Department of Surgery and Interdisciplinary Medicine (DCMT), University of Milano Bicocca, Monza, Italy.
authors.forename: Simone
authors.initials: S
authors.lastname: Beretta
authors.affiliation: Laboratory of Experimental Stroke Research, Department of Surgery and Interdisciplinary Medicine (DCMT), University of Milano Bicocca, Monza, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Carone
authors.affiliation: Laboratory of Experimental Stroke Research, Department of Surgery and Interdisciplinary Medicine (DCMT), University of Milano Bicocca, Monza, Italy.
authors.forename: Giovannibattista
authors.initials: G
authors.lastname: Pappadà
authors.affiliation: Department of Neurosurgery, Erasme Hospital, University of Brussels, Brussels, Belgium.
authors.forename: Michael
authors.initials: M
authors.lastname: Bruneau
authors.affiliation: Laboratory of Experimental Stroke Research, Department of Surgery and Interdisciplinary Medicine (DCMT), University of Milano Bicocca, Monza, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Giussani
authors.affiliation: Laboratory of Experimental Stroke Research, Department of Surgery and Interdisciplinary Medicine (DCMT), University of Milano Bicocca, Monza, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Paternò
authors.affiliation: Laboratory of Experimental Stroke Research, Department of Surgery and Interdisciplinary Medicine (DCMT), University of Milano Bicocca, Monza, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Versace
authors.affiliation: Laboratory of Experimental Stroke Research, Department of Surgery and Interdisciplinary Medicine (DCMT), University of Milano Bicocca, Monza, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Ferrarese
authors.affiliation: Laboratory of Experimental Stroke Research, Department of Surgery and Interdisciplinary Medicine (DCMT), University of Milano Bicocca, Monza, Italy.
authors.forename: Erik
authors.initials: E
authors.lastname: Sganzerla
mesh_terms: D000818:Animals; D001166:Arteriovenous Shunt, Surgical / Q000379:methods* / Q000592:standards; D001026:Coronary Artery Bypass / Q000379:methods* / Q000592:standards; D004195:Disease Models, Animal; D006439:Hemodynamics / Q000502:physiology*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley