Heart and Vessels

, Volume 11, Issue 2, pp 69–79

Effect of clot removal on cerebrovascular contraction after subarachnoid hemorrhage in the monkey: Pharmacological study

  • Tsutomu Tsuji
  • David A. Cook
  • Bryce K. A. Weir
  • Yuji Handa

DOI: 10.1007/BF01744506

Cite this article as:
Tsuji, T., Cook, D.A., Weir, B.K.A. et al. Heart Vessels (1996) 11: 69. doi:10.1007/BF01744506


Clot removal at early surgery has been reported to be clinically effective for the prevention of cerebral vasospasm following subarachnoid hemorrhage (SAH) due to rupture of an intracranial aneurysm. We examined the most efficacious timing of mechanical clot removal on pharmacological responses in a monkey SAH model. Cynomolgus monkeys (Macaca fascicularis) were randomized into five groups: sham-operated, clot removal in which the clot was removed 48, 72, or 96h after SAH, and clot groups. An autologous blood clot was placed around the bilateral major cerebral arteries after craniectomy to mimic the hemorrhage. Seven days after the SAH, proximal and successively distal parts of the middle cerebral arteries were cut into rings for isometric tension measurement. The contractile responses to potassium chloride, 5-hydroxytryptamine, norepinephrine, adenosine triphosphate, prostaglandin F, and hemoglobin were greater in the proximal parts than in the distal parts in each group. Compared with the sham-operated group, the responses of the clot-removal and clot groups to the drugs were progressively attenuated. The maximum responses to 5-hydroxytryptamine in the proximal parts and to adenosine triphosphate in the distal parts started to decrease, significantly, in the clot-removal group 48h after SAH, while most of the responses to the other agonists began to decrease in the clot-removal groups later than 72h after SAH. These results suggest that the attenuation of cerebrovascular contractile responses 7 days after SAH is pharmacologically inevitable, even if the clot is removed as early as 48h after the SAH. Clot removal may thus be recommended within 48h after SAH to ameliorate the severity of cerebral vasospasm following SAH.

Key words

Vascular contractionClot removalSubarachnoid hemorrhageCerebral vasospasm

Copyright information

© Springer-Verlag 1996

Authors and Affiliations

  • Tsutomu Tsuji
    • 1
  • David A. Cook
    • 2
  • Bryce K. A. Weir
    • 3
  • Yuji Handa
    • 4
  1. 1.Department of NeurosurgeryShinshu University School of MedicineMatsumotoJapan
  2. 2.Department of PharmacologyFaculty of Medicine, University of AlbertaEdmontonCanada
  3. 3.Section of NeurosurgeryThe University of Chicago Medical CenterChicagoUSA
  4. 4.Department of NeurosurgeryFukui Medical SchoolMatsuoka, FukuiJapan