Detailed Description:

Breast cancer is the most common malignancy in women; surgery is still the mainstay for the treatment of breast cancer . Postoperative pain can seriously reduce the quality of patient's life, and acute pain can even trigger chronic pain syndrome. Thoracic paravertebral, thoracic epidural, intercostal nerve, and interscalene brachial plexus blocks have been used for anesthesia and abirritation during mastectomy, but their applications are limited by the complicated technique of the procedures and several complications. In recent years, there has been increasing interest on a novel, less invasive technique, the pectoral nerve (PECS) block. Numerous clinical trials have focused on the analgesic potential of the pectoral nerve block in breast augmentation surgery, small breast surgery, and breast cancer surgery, and have shown positive results. Several prospective observational studies in recent years demonstrated that postoperative pain following breast surgery becomes chronic in up to 57% of women. One of the most important risk factors is insufficiently treated postoperative acute pain. The current gold standard for acute postoperative pain is a preventive procedure-specific multimodal treatment including nonopioids, opioids and regional analgesia. A recently published Cochran's meta-analysis demonstrated that regional analgesia [e.g. paravertebral block (PVB), local infiltration] might even reduce the risk of chronic postsurgical pain after breast surgery. According to a recently published guidelines, pectoral nerves (PECS) blocks seem to be an effective alternative to PVB to manage effectively postsurgical pain in major breast surgery.Anatomical studies revealed a different local anaesthetic spread following injections between the pectoralis major and minor muscles (PECS I) and a combination of the latter injection with a deeper injection between the pectoralis minor and serratus anterior muscles (PECS II) but the results were not conclusive. Many trials have been published and some meta-analyses revealed a high analgesic efficacy following PECS II blocks compared with no block or PVB. However, one of these meta-analyses was criticised because of methodological problems (e.g. evidence assessment, missing sham block group), pain intensities not analysed separately for resting pain and pain during movement and comparisons with other established or emerging regional anaesthetic techniques (e.g. local infiltration, erector spinae block) were not performed.}}