Paradoxic Relations between Basilar Artery Reconfiguration and Superior Cervical Ganglia Ischemia After Bilateral Common Carotid Artery Ligation

Abstract

The relationship between superior cervical ganglia (SCG) ischemia due to bilateral common carotid artery ligation (BCCAL) and basilar artery (BA) reconfiguration was investigated. 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). Mean live and DND in SCG of group I rabbits were 11.235 ± 982/μm3 and 11 ± 3/μm3, respectively, with a mean heart rate of 294 ± 21 beats/min. Mean SCG DND and heart rates were 213 ± 42/μm3 and 242 ± 17 beats/min for the sham group (group II) rabbits and 1743 ± 285/μm3 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). 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.