The efficacy of superficial cervical plexus blocks for reducing persistent pain after craniotomies remains unclear. We therefore tested the primary hypothesis that preoperative ultrasound-guided superficial cervical plexus blocks reduce persistent pain 3 months after suboccipital craniotomies.
We conducted a single-center randomized and blinded parallel-group trial. Eligible patients having suboccipital craniotomies were randomly allocated to superficial cervical plexus blocks with 10 ml of 0.5% ropivacaine or a comparable amount of normal saline. Injections were into the superficial layer of prevertebral fascia. The primary outcome was the incidence of persistent pain three months after surgery.
From Nov 2021 to August 2023, 292 qualifying patients were randomly allocated to blocks with ropivacaine (n=146) or saline (n=146). The average ± SD age of participating patients was 45±12 years and the duration of surgery was 4.2±1.3 hours. Persistent pain 3 months after surgery was reported by 48 (34%) of patients randomized to ropivacaine versus 73 (51%) in those assigned to saline (relative risk 0.66; 95% CI, 0.50 to 0.88; P = 0.003) in the per-protocol population, and by 53 (36%) of patients randomized to ropivacaine versus 77 (53%) in those assigned to saline (relative risk 0.69, 95% CI, 0.53 to 0.90; P = 0.005) in the intention-to-treat population.
Superficial cervical plexus blocks reduce the incidence of persistent incisional pain by about a third in patients recovering from suboccipital craniotomies.
