Paravertebral vs. Serratus Anterior Block for Thoracic Surgery

Disclaimer: This article is intended solely for informational and educational purposes only. It does not constitute medical advice.

Regional anesthesia is an important component of thoracic surgery that reduces opioid consumption and improves postoperative recovery. Among the available regional techniques providing analgesia for the chest area, thoracic paravertebral block (PVB) and serratus anterior plane block (SAPB) have emerged as commonly utilized options. Both techniques provide effective analgesia for thoracic procedures, but they differ in anatomical targets, technical complexity, and analgesic efficacy. Understanding these differences allows anesthesiologists to select the most appropriate block based on patient and surgical factors. 

Thoracic paravertebral block involves deposition of local anesthetic adjacent to the thoracic vertebral bodies within the paravertebral space. The block anesthetizes spinal nerves as they emerge from the intervertebral foramina, producing unilateral somatic and sympathetic blockade over multiple dermatomes. PVB has long been considered one of the most effective regional techniques for thoracotomy and video-assisted thoracoscopic surgery. Numerous studies have demonstrated reductions in postoperative pain scores, opioid consumption, nausea, and pulmonary complications compared with systemic analgesia alone. 

In contrast, the serratus anterior plane block is a more superficial ultrasound-guided fascial plane block. Local anesthetic is injected either superficial to or deep in the serratus anterior muscle, targeting the lateral cutaneous branches of the intercostal nerves. SAPB primarily provides analgesia to the anterolateral chest wall, making it particularly useful for minimally invasive thoracic procedures, rib fractures, and breast surgery. Because the injection occurs farther from the neuraxis and pleura, SAPB is often considered technically simpler and potentially safer than PVB. 

Comparative studies generally demonstrate superior analgesic efficacy with paravertebral block over serratus anterior plane block for thoracic surgery. Patients receiving paravertebral blocks report lower pain scores and have reduced opioid requirements during the first 24 to 48 postoperative hours. The broader dermatomal coverage and sympathetic blockade provided by PVB contribute to its effectiveness, particularly following painful procedures such as thoracotomy. Some investigations have reported analgesia approaching that of thoracic epidural analgesia while avoiding many of the hemodynamic side effects associated with epidural techniques. 

Despite its advantages, PVB presents several challenges. The procedure requires greater technical expertise and carries risks including inadvertent pleural puncture, pneumothorax, vascular puncture, and epidural spread of local anesthetic. Ultrasound guidance has improved the safety profile of the technique, but complications remain possible. In anticoagulated patients or individuals with altered thoracic anatomy, PVB may be less desirable. 

The serratus anterior plane block offers several practical advantages. Ultrasound landmarks are generally easy to identify, and the block can be performed quickly with the patient in multiple positions. Because the injection site is superficial, the risk of serious complications is relatively low. SAPB may be particularly attractive in enhanced recovery pathways where simplicity and efficiency are priorities. However, its analgesic effect may be less comprehensive, especially for procedures involving deeper thoracic structures or extensive posterior chest wall incisions. 

Current evidence suggests that paravertebral block remains the preferred regional technique when maximal analgesia is required after thoracic surgery, but serratus anterior plane block represents an effective alternative when technical limitations, patient comorbidities, or safety considerations make paravertebral block less desirable. Both techniques can significantly reduce perioperative opioid requirements and contribute to enhanced recovery after thoracic procedures. Selection should be individualized based on surgical invasiveness, patient risk factors, provider expertise, and institutional resources. 

References 

1. Yeung JH, Gates S, Naidu BV, Wilson MJ, Gao Smith F. Paravertebral block versus thoracic epidural for patients undergoing thoracotomy. Cochrane Database Syst Rev. 2016;2:CD009121. DOI: 10.1002/14651858.CD009121.pub2 
2. Elsharkawy H, Maniker R, Bolash R, Kalasbail P, Drake RL, Mariano ER. Serratus plane block: a narrative review. Reg Anesth Pain Med. 2018;43(5):493-498. DOI: 10.21037/apm-20-1542  
3. Fu Y, Zhang X, Xu H, et al. Comparison of serratus anterior plane block and thoracic paravertebral block for postoperative analgesia after thoracoscopic surgery: a meta-analysis. J Cardiothorac Vasc Anesth. 2023;37(4):1160-1168. DOI: 10.5606/tgkdc.dergisi.2024.26887 
4. Kotzé A, Scally A, Howell S. Efficacy and safety of thoracic paravertebral block in thoracic surgery: a systematic review and meta-analysis. Br J Anaesth. 2009;103(5):626-636. DOI: 10.1093/icvts/ivt551 
5. Karmakar MK. Thoracic paravertebral block. Anesthesiology. 2001;95(3):771-780. DOI: 10.1097/00000542-200109000-00033