The ‘pecs block’: a novel technique for providing analgesia after breast surgery

I read the recent article by Finnerty and colleagues with interest 1 and would like to present a novel interfascial plane block. Breast surgery is one of the most common forms of surgery conducted in hospitals. Even relatively minor breast surgery can be associated with significant postoperative pain 2. Paravertebral blocks have become popular as an alternative to the analgesia provided by the ‘gold standard’ of thoracic epidural analgesia 3. However, both regional techniques have complications that make them unsuitable for day surgery, and therefore unsuited to the large proportion of breast surgery patients who are treated on a day-stay basis. I describe here a simple new alternative approach as a practicable alternative to both paravertebral and epidural blockade in the management of pain after breast surgery. I have called this new block the ‘pecs block’, as the aim is to place local anaesthetic into the interfascial plane between pectoralis major and minor muscles (Fig. 4). I have performed this block in approximately 50 patients over the last 2 years, and have found that the patients require only minimal analgesia postoperatively (only regular paracetamol and dexketoprofen). The block seems particularly useful for patients who have breast expanders placed during reconstructive breast cancer surgery or subpectoral prostheses. Graphic representation of the area of injection under the pectoralis major muscle. Under the upper part of pectoralis minor (Pm), the pectoral branch of the thoracoacromial artery (taa) is easily identified with the lateral pectoral nerve (lpn) adjacent to it. At that level, the medial pectoral nerve (mpn) is underneath the minor pectoral nerve. (© Primal Pictures, http://www.primalpictures.com/). The anatomical site of the block is superficial and I perform the procedure with a linear ultrasound probe, using a similar probe position to that used when performing an infraclavicular brachial plexus block. Once I have identified the pectoralis major muscle, I check the location of the pectoral branch of the thoraco-acromial artery between the pectoralis muscles with colour Doppler. The lateral pectoral nerve is consistently located adjacent to the artery. I use standard 50-mm block needles to infiltrate the interfascial plane with 0.4 ml.kg−1 levobupivacaine 0.25% (Fig. 5). A catheter can readily be placed into the interfascial plane, and I have found 5 ml.h−1 infusions of levobupivacaine 0.25% for up to 7 days to be effective. Using this continuous technique, I find opioid analgesia is only very rarely needed in the postoperative period. Infiltration into the interpectoral plane at infraclavicular level. PM, pectoralis major and Pm; pectoralis minor muscles; AA, axillary artery; AV, axillary vein. The ‘pecs block’ performed under ultrasound guidance is feasible and I have found that patients require little extra analgesia and that the block is suitable in the day-care setting. This now requires formal evaluation of efficacy and safety.