Stellate Ganglion Block and Cerebral Vasospasm

Effect of Early Stellate Ganglion Block for Cerebral Vasospasm After Aneurysmal Subarachnoid Hemorrhage: a Randomized Controlled Trial (BLOCK-CVS)

At present, cerebral vasospasm (cVS) is the main cause of delayed cerebral infarction (DCI), which leads to high disability and mortality rate after aneurysmal subarachnoid hemorrhage. As a consequence, the key of reducing DCI is to prevent cVS. But unfortunately, despite years of efforts, the prevention and treatment of cVS is still a major clinical dilemma and various ways of treatment are still being explored. Recent studies have shown that stellate ganglion block (SGB) can dilate cerebral vessels and alleviate the impact of existing cVS. However, there is no study to evaluate the effect of early application of SGB on the improvement and prevention of cVS after aSAH.

Cerebral vasospasm refers to the extensive segmental or diffuse contraction of cerebral vasculature after aSAH, and cerebral blood flow is significantly reduced, which can lead to delayed cerebral ischemia (DCI) or delayed ischemic neurological dysfunction (DIND). Past studies have shown that if cerebral vasospasm occurs in patients with aSAH, the proportion of ischemic brain injury can be as high as 20%-30%.Obviously, prevention and treatment of CVS are the key to reducing the disability and mortality of aSAH.

Inclusion Criteria:

• Age range: 18-65 years old;
• Within 48 hours after onset of aSAH,and planning surgical treatment(aneurysm clipping);
• Preoperative Hunt-Hess grade 2-3
• Sign informed consent.

Exclusion Criteria:

• ASA > grade III;
• Patients with posterior circulation aneurysm, ophthalmic aneurysms or internal carotid aneurysms;
• patients with multiple aneurysms;
• Patients with severe coagulation dysfunction;
• Patients with trauma and local infection in the nerve block area;
• Local anatomic structure changes (neck structure changes caused by radiotherapy, chemotherapy and surgery);
• MCA stenosis or infarction was found by preoperative imaging;
• Patients with poor temporal window signal revealed by preoperative TCD (clear waveform image could not be obtained);
• Allergy to known local anesthetics;
• Pregnant and lactating women.