Local infiltration anesthesia (anterior field block) vs. general anesthesia for thyroidectomy: effects on operative time, complications, and cost—a GRADE-assessed systematic review and meta-analysis with subgroup analysis

Abstract

Thyroidectomy involves the removal of part or all of the thyroid gland, commonly performed for goiters, hyperthyroidism, or carcinomas, with 450,000–500,000 procedures performed annually in the United States. General anesthesia is traditionally used, providing optimal surgical conditions but associated with risks such as cardiovascular complications and longer hospital stays. Local anesthesia is gaining interest for high-risk patients, offering potentially similar outcomes to general anesthesia, while reducing postoperative complications and costs. The choice of anesthetic technique impacts patient safety, healthcare costs, and overall experience, yet no meta-analysis has previously compared local and general anesthesia for thyroidectomy. This systematic review and meta-analysis aimed to compare surgical and perioperative outcomes of general anesthesia vs. local anesthesia in thyroidectomy, focusing on operative time, complications, cost, and postoperative recovery, to inform clinical practice. This review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A systematic search of PubMed/MEDLINE, Embase, Web of Science, and Scopus was performed from database inception to August 2025. We included randomized controlled trials, cohort studies, and case–control studies comparing local infiltration anesthesia with general anesthesia in patients with thyroidectomy. Key outcomes included operative time, intraoperative and postoperative complications, hospital stay length, pain scores, patient satisfaction, and cost. Data were extracted independently by two authors. Risk of bias was assessed using the Cochrane Risk of Bias 2 (RoB 2) tool for randomized trials and the Risk of Bias In Non-Randomized Studies of Interventions tool for non-randomized studies. Certainty of evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation framework. Statistical analysis was performed using Review Manager (RevMan), calculating mean differences and risk ratios under a random-effects model, with heterogeneity assessed using the I 2 statistic. Statistical significance was set at p  < 0.05. The systematic search identified 1,785 studies, of which 252 duplicates were removed. After screening, 1,508 studies were excluded, leading to a full-text review of 25 studies and ultimate inclusion of 5 studies comprising 508 patients undergoing thyroid surgery with either local or general anesthesia. Local anesthesia was associated with a shorter operative time than general anesthesia (mean difference −18.32 min, 95% CI: −27.31 to −9.15), but heterogeneity was high ( I 2  = 95%), and the effect was significant only in cohort studies and not in randomized trials, and therefore, this finding should be interpreted with caution. No significant differences were observed between groups in nerve injury or respiratory distress, although evidence certainty for these outcomes was low. A cost analysis suggested that local anesthesia was less expensive than general anesthesia across all studies reporting cost data. Patient satisfaction appeared comparably high in both groups across the studies that assessed this factor. Local anesthesia was associated with shorter operative times, lower costs, and shorter hospital stays compared with general anesthesia in thyroidectomy. However, these findings are drawn from a small number of studies and therefore should be interpreted cautiously. General anesthesia also likely remains necessary for more advanced procedures requiring airway control and complete patient immobility.