Comparison of PECS II Block and Combined Serratus Anterior Plane Block to Reduce Acute Pain After Mastectomy

Breast cancer ranks first among the most common malignant neoplasms in women. Surgery has been a mainstay of breast cancer treatment for several decades and historically, a modified radical mastectomy was the primary method of treatment for breast cancer. Poorly controlled acute postoperative pain is associated with increased morbidity, functional and quality-of-life impairment. Additionally, severe acute postoperative pain is found to be a risk factor for chronic pain.

Thoracic paravertebral, thoracic epidural, intercostal nerve, and interscalene brachial plexus blocks have been used for anesthesia and abirritation during modified radical mastectomy, but their application is limited due to the complex nature of the procedures and serious complications. There is growing interest in the pectoralis nerve (PECS) blocks and serratus anterior block (SAB) which are less invasive as an analgesic technique during breast surgeries to reduce postoperative pain.

The Pecs I block is a single injection of local anaesthetic between pectoralis major and pectoralis minor muscles at the level of the 3rd rib to anaesthetise the lateral and medial pectoral nerves. The Pecs II block is a modified Pecs I block and can be achieved with one needle insertion point. Local anaesthetic is placed between pectorals major and minor as for a Pecs I block and then between pectoralis minor and serratus anterior muscles.

Numerous clinical studies focusing on the analgesic potential of PECS block in breast augmentation surgery, small breast surgery and breast cancer surgery have yielded positive results. SAD is more superficial, easy to access and less likely to have complications like PECS block. SAPB can be implemented in two ways. Deep SAB (DSAB) is applied under the serratus anterior muscle, while superficial SAB (YSAB) is applied over the serratus anterior muscle. In recent years, deep and superficial SAB, that is, combined SAB (CSAB), has been started to be applied in order to increase the effect area of local anesthetics and to prevent block failure.

In this study, PECS II block or CSAB will be applied to patients who have had a modified radical mastectomy under general anesthesia for postoperative pain relief by using 30 ml of 0.25% bupivacaine .All patients will receive tramadol with a patient-controlled analgesia device during the postoperative period. Pain, nausea-vomiting, additional analgesic and antiemetic drug requirement, within 24 hours postoperatively will be compared between groups.