Paradoxical Relations between Basilar Artery Reconfiguration and Superior Cervical Ganglia Ischemia Following Bilateral Common Carotid Artery Ligation.

ACKGROUND: The relationship between superior cervical ganglia (SCG) ischemia due to bilateral common carotid artery ligation (BCCAL) and basilar artery (BA) reconfiguration was investigated.

METHOD: Twenty-three rabbits were randomly divided into three groups: GIII rabbits underwent BCCAL (n = 13), GII rabbits were sham-operated controls (n = 5), and GI rabbits did not undergo surgery (n = 5). Degenerated neuron densities (DND) within SCG were correlated with the BA vasodilatation index (VDI).

RESULTS: Mean live and DND in SCG of GI 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 sham group (Group II) rabbits and 1743 ± 285/μm3 and 199 ± 19 beats/min for study group (Group III) rabbits, respectively. BA VDI values in sham group (Group II) (1.32 ± 0.10) and study group (Group III) rabbits, (0.976 ± 0.112) rabbits significantly differed from those in control group (Group I) (1.65 ± 0.12; P< 0.005 vs sham group (Group II); P< 0.0001 vs BCCAL applied group (Group III) and between Group II and Group III rabbits (P< 0.005).

CONCLUSION: A meaningful and paradoxical correlation was detected between the BA VDI values and degenerated neuron density of SCG following 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.