Serratus and Parasternal Infrapectoral Block for Breast Surgery. A Randomized Controlled Double Blinded Study to Measure Impact on Time to Hospital Discharge in an Outpatient Setting.

Study Introduction:

Severe acute postoperative pain affects nearly 60% of breast surgery patients, potentially triggering adverse physiological and psychological responses, increased chronic pain incidence, and elevated healthcare costs. Effective perioperative pain management reduces chronic pain occurrence, improves recovery quality, and enables early hospital discharge, thus reducing overall healthcare expenses. Various analgesic strategies exist, ranging from regional techniques to opioid-based approaches. Combining multimodal analgesia with regional anesthesia offers superior pain control and enhances recovery quality. The chest wall and breast skin receive innervation from intercostal nerves, with branches providing sensory input to different areas. Understanding this innervation pattern is crucial for optimizing analgesic approaches in breast surgery and ensuring comprehensive pain relief across all affected regions.

Regional analgesic techniques offer several advantages over traditional parenteral opioid therapy, including enhanced pain relief, reduced opioid consumption and related side effects, quicker PACU discharge, and lower chronic pain occurrence. Paravertebral analgesia is particularly effective for breast surgery but presents drawbacks that limit its popularity, such as variable sensory distribution, potential epidural spread, failure rates, and serious risks like total spinal anesthesia or pneumothorax. Interfascial block techniques, aided by ultrasound, have gained traction in regional anesthesia. These techniques involve injecting local anesthetic into neuro-fascial planes adjacent to muscles or between muscle layers, facilitating its distribution to nerves. Interfascial blocks offer advantages like ease of performance, increased safety by avoiding direct nerve targeting, fewer injections, and superficial application, reducing risks associated with deeper nerve blocks. Given these benefits and a thorough understanding of thoracic wall anatomy, several interfascial blocks have been developed as alternatives to paravertebral blocks, aiming for equal efficacy with fewer risks, particularly important in the context of day case breast surgeries.

The serratus block for breast surgery:

The Serratus Plane Block, introduced by Blanco in 2013, involves injecting local anesthetic beneath the serratus anterior muscle to target intercostal nerve branches. However, our recent anatomical study revealed that a single midaxillary line injection inadequately covers the entire breast, prompting additional parasternal injections for comprehensive sensory coverage. Despite this refinement, no randomized controlled trial has yet assessed the efficacy of combined serratus and parasternal infrapectoral blocks in breast surgery analgesia.