title: Does external stenting reduce porcine vein-graft occlusion via an action on vascular nerves?
abstract: BACKGROUND
  Neural reorganization occurs in porcine vein grafts and placement of an external stent reduces graft occlusion.
  
  
  OBJECTIVE
  To determine the effect of external stenting on the innervation of porcine vein grafts.
  
  
  METHODS
  Saphenous vein into carotid artery grafting (with and without external stents) was performed in 16 pigs. After one and six months, grafts were removed, nerves were counted, and neointima was assessed.
  
  
  RESULTS
  In vein graft compared to ungrafted vein, there was a significant (p < 0.05) decrease in medial perivascular nerves, but a dramatic increase in paravascular nerves in the adventitia (p < 0.05). In stented vein grafts there was also a reduction of perivascular nerves and the paravascular nerve proliferation observed in vein grafts at one month was inhibited (p < 0.05). Neointima formation and the appearance of large paravascular nerve bundles in the adventitia of vein grafts were abolished by external stenting.
  
  
  CONCLUSIONS
  Neural reorganization plays a role in vein-graft failure, possibly through the local release of mitogens; the prevention of this reorganization contributes to the inhibitory effect of the external stent on neointima formation.
authors.affiliation: Department of Clinical Biochemistry, Royal Free and University College Medical School, London, United Kingdom. mdashwood@rfc.ucl.ac.uk
authors.forename: M R
authors.initials: MR
authors.lastname: Dashwood
authors.forename: G D
authors.initials: GD
authors.lastname: Angelini
authors.forename: S
authors.initials: S
authors.lastname: Wan
authors.forename: A
authors.initials: A
authors.lastname: Yim
authors.forename: D
authors.initials: D
authors.lastname: Mehta
authors.forename: M B
authors.initials: MB
authors.lastname: Izzat
authors.forename: J Y
authors.initials: JY
authors.lastname: Jeremy
mesh_terms: D000818:Animals; D017776:Autonomic Pathways / Q000378:metabolism / Q000601:surgery*; D019917:Blood Vessel Prosthesis Implantation; D004195:Disease Models, Animal; D006083:Graft Occlusion, Vascular / Q000378:metabolism / Q000601:surgery*; D009131:Muscle, Smooth, Vascular / Q000294:innervation / Q000378:metabolism; D012501:Saphenous Vein / Q000294:innervation / Q000378:metabolism / Q000637:transplantation; D015607:Stents; D013552:Swine; D013997:Time Factors; D017539:Tunica Intima / Q000294:innervation / Q000378:metabolism