Effect of stellate ganglion block on cerebral vasospasm in patients undergoing intracranial aneurysm surgery

Abstract

Objective To evaluate the effect of stellate ganglion block (SGB) on cerebral vasospasm in patients undergoing intracranial aneurysm surgery. Methods Forty ASA Ⅱ or Ⅲ patients aged 14-64 yr weighing 40-81 kg undergoing intracranial aneurysm clipping were randomly divided into 2 groups ( n = 20 each): group control (group C) and group SGB. Left SGB was performed with 0.25% ropivacaine 10 ml immediately after intubation. Successful block was verified by development of Homer syndrome within 15 min after block. Anesthesia was induced with midazolam, propofol, fentanyl and vecuronium and maintained with isoflurane inhalation and intermittent iv boluses of fcntanyl and vecuronium. The patients were intubated and mechanically ventilated. PETCO2 was maintained at 30-35 mm Hg. BIS was maintained at 50-60. Right internal jugular vein was cannulated and the catheter was threaded cranially until resistance was met for blood sampling. Blood samples were collected before skin incision (T1), before clipping of aneurysm (T2), at 30 min after clipping (T3 ), and at the end of surgery (T4) for determination of plasma concentrations of endothelin (ET), calcium gene-related peptide (CGRP) and S100B protein. Transcranial Doppler was used to measure the flow rate of blood in bilateral middle cerebral artery and extracranial carotid artery at 1 and 3 days after surgery. All patients were observed for incidence of brain ischemia during 1-7 days after surgery. Results Plasma ET and S100B protein concentrations were significantly decreased, while plasma CGRP concentration was significantly increased after clipping of aneurysm at T3 and T4 in group SGB as compared with group C. The incidence of cerebral vasospasm and brain ischemia was significantly lower in group SGB than in group C. Conclusion SGB performed before operation can significantly reduce the incidence of cerebral vasospasm after clipping of intracranial aneurysm by inhibiting the release of ET and promoting the release of CGRP. Key words: Nerve block; Stellate ganglion; Neurosurgical procedures; Vasopasm,intracranial