title: Denervation of gastroepiploic artery graft can reduce vasospasm.
abstract: BACKGROUND
  The right gastroepiploic artery is useful as an in situ arterial graft for coronary artery bypass grafting. However, the gastroepiploic artery is more likely to cause vasospasms compared with the internal thoracic artery. We hypothesized that the cause of the spasms is the stimulation of the periarterial sympathetic nerve, because the gastroepiploic artery is classified as a muscular artery. In this study, we examined whether the spasm is reduced by removing the periarterial sympathetic nerve.
  
  
  METHODS
  Unused parts of the gastroepiploic artery were obtained from patients who underwent coronary artery bypass grafting. The vessel was cut into 2 segments, and they were assigned to control (N+) and denervation (N-) groups. The periarterial nerve was microscopically removed from the vessels of the N- group. The vessels in both groups were investigated by hematoxylin-eosin or immunohistochemical staining, and they were stimulated by electrical field stimulation with serial frequency for isometric tension measurement.
  
  
  RESULTS
  Histologic analyses revealed that periarterial connective tissues including neuropeptide Y were removed to expose the external elastic membrane in the N- vessel, whereas they were preserved in N+. The mean contraction by electrical field stimulation with serial frequency was consistently lower in N- than in N+ (P < .05 at 20 and 50 Hz; n = 8 each). Endothelium-dependent relaxation and contractile function of the smooth muscle were similar in both groups.
  
  
  CONCLUSIONS
  The removal of the periarterial sympathetic nerve from the human gastroepiploic artery reduced vascular contraction, elicited by peripheral nerve stimulation, without disturbing endothelial and smooth muscle contractile functions. This reduction may contribute to the prevention of vasospasms.
authors.affiliation: Department of Cardiovascular Surgery, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Yokoyama
authors.affiliation: Department of Cardiovascular Surgery, Juntendo University School of Medicine, Tokyo, Japan. Electronic address: saty-m@juntendo.ac.jp.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Matsushita
authors.affiliation: Department of Physiology, Juntendo University Faculty of Medicine, Tokyo, Japan.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Iesaki
authors.affiliation: Department of Cardiovascular Surgery, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Taira
authors.initials: T
authors.lastname: Yamamoto
authors.affiliation: Department of Cardiovascular Surgery, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Inaba
authors.affiliation: Department of Physiology, Juntendo University Faculty of Medicine, Tokyo, Japan.
authors.forename: Takao
authors.initials: T
authors.lastname: Okada
authors.affiliation: Department of Cardiovascular Surgery, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Amano
mesh_terms: D000320:Adrenergic Fibers / Q000737:chemistry; D001157:Arterial Occlusive Diseases / Q000503:physiopathology / Q000517:prevention & control*; D015415:Biomarkers / Q000032:analysis; D003251:Constriction, Pathologic; D004558:Electric Stimulation; D024405:Gastroepiploic Artery / Q000294:innervation* / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D007537:Isometric Contraction; D009478:Neuropeptide Y / Q000032:analysis; D013562:Sympathectomy; D014661:Vasoconstriction; D014664:Vasodilation
chemical_list: D015415:Biomarkers; D009478:Neuropeptide Y