Paradoxic relations between basilar artery reconfiguration and superior cervical ganglia ischemia after bilateral common carotid artery ligation

Abstract

BACKGROUND: the relationship between superior cervical ganglia (SCG) ischemia due to bilateral common carotid artery ligation (BCCAL) and basilar artery (BA) reconfiguration was investigated. METHODS: Twenty-three rabbits were randomly divided into 3 groups: group III rabbits underwent BCCAL (n = 13), group II rabbits were sham-operated controls (n = 5), and group I rabbits did not undergo surgery (n = 5). Degenerated neuron densities (DND) within the SCG were correlated with the BA vasodilatation index (VDI). RESULTS: Mean live and DND in SCG of group I rabbits were 11.235 +/- 982/mu m(3) and 11 +/- 3/mu m(3), respectively, with a mean heart rate of 294 +/- 21 beats/min. Mean SCG DND and heart rates were 213 +/- 42/mu m(3) and 242 +/- 17 beats/min for the sham group (group II) rabbits and 1743 +/- 285/mu m(3) and 199 +/- 19 beats/min for the study group (group III) rabbits, respectively. the BA VDI values in the sham group (group II) (1.32 +/- 0.10) and the study group (group III) (0.976 +/- 0.112) significantly differed from those in the control group (group I) (1.65 +/- 0.12; P < 0.005) versus the sham group (group II) (P < 0.0001) versus the BCCAL applied group (group III) and between group II and group III (P < 0.005). CONCLUSIONS: A meaningful and paradoxic correlation was detected between the BA VDI values and degenerated neuron density of SCG after BCCAL. Although a low degenerated neuron density within SCG may provoke excessive sympathetic activity and prevent excessive BA dilatation with steno-occlusive carotid artery diseases, a high degenerated neuron density may cause dangerous vasodilatation of BA.