Establishment of A Mouse Model of Stellate Ganglion Block and Subsequent Biphasic Effects on Bilateral Cerebral Cortical Blood Flow

Background and objectives: Stellate ganglion block (SGB) has significant therapeutic efficacy in various clinical practices and further exploration of SGB is needed. The mouse model of SGB had not been reported and the effect on cerebral cortical blood flow (CCBF) was controversial. We aimed to establish an stellate ganglion block (SGB) mouse model and explore how SGB influences CCBF. Methods: Male C57BL/6 mice were randomly divided into five groups (n = 6): groups L (left SGB) and R (right SGB) received an injection of 0.25% ropivacaine hydrochloride (0.08 mL) on the respective stellate ganglion; similarly, groups SL (left saline control) and SR (right saline control) received an injection of normal saline (0.08 mL) instead. Group C received no intervention. CCBF was assessed before SGB (T0) and 10 (T1), 30 (T2), 60 (T3), 90 (T4), and 120 min (T5) after SGB using laser speckle contrast imaging system. Results: The SGB mouse model was successfully established in groups L and R. Compared with baseline, CCBF on the blocked side decreased at T1, increased at T2–T5, and peaked at T3 in groups L and R (all, P < 0.01). Compared with groups C and SL, the CCBF on the left side decreased at T1 and increased at T2–T5 in group L (all, P < 0.05). A similar trend was noted in groups C and SR relative to group R. The CCBF on the unblocked side decreased at T1, increased at T2–T5, and peaked at T3 in groups L and R (all, P < 0.01). Conclusions: The SGB mouse model was established successfully. Unilateral SGB can affect bilateral cerebral cortical blood flow, which shows a transitory decrease followed by a significant increase for at least 2 h.