Anatomical study of the “Three in one” pectoral block. A new analgesia method for breast surgery

Breast cancer surgery is associated with severe postoperative pain. Novel techniques improving postoperative analgesia have been recently described such as pectoral nerves blocks (Pecs types I and II). The purpose of this study is to describe a new pectoral block targeting the whole breast region nerves and spaces. Ten women fresh cadavers were dissected. An unique puncture was realized at the medioclavicular line level, 3 cm under the clavicle. The orientation of the needle was medio‐lateral and oblique, tangential to costal plane. Under ultrasound control the first injection was at the serrato‐costal plane level between anterior serratus deep fascia and exothoracic fascia. The second injection was in the serrato‐pectoral plane, localized between anterior serratus superficial fascia and clavipectoral deep fascia. The third injection was more superficial in the interfascial plane between pectoralis major and minor muscles. A last subcutaneous injection is performed at the puncture point. After dissection of the two sides of each cadaver, serrato‐costal plane injections blocked thoracic intercostal nerves anterior divisions, serrato‐pectoral plane injections targeted long thoracic and thoracic intercostal nerves lateral division, and interpectoral plane dissections blocked lateral and medial pectoral nerves. The supraclavicular nerve is blocked with the subcutaneous injection at the puncture point. This « three in one » pectoral block realized the analgesia of whole breast region nerves. To our knowledge it's the first time that such a block with an unique puncture is described.