Editor-in-Chief: Kenneth D. Candido, MD
BACKGROUND: Breast cancer surgery is often associated with severe postoperative pain that may compromise systemic homeostasis, which increases perioperative morbidity, the length of stay in the hospital, and costs. Scientific evidence has also shown that an inadequate analgesia could promote the risk of persistent pain development after breast surgery.
OBJECTIVE: Recent literature suggested that the pectoral nerves II (PECS II) block may represent a valid alternative to general anesthesia (GA) and conventional, regional techniques for analgesia in breast surgery. This technique may provide complete anesthesia of the lateral part of the thorax but cannot block, by itself, the anterior cutaneous branches of the intercostal nerves. The combination of a parasternal block (PSB) and a PECS II block has been performed as a single anesthetic technique.
STUDY DESIGN: This is an observational, mono-center, prospective, and cohort study. We obtained the approval of our scientific ethic committee and clinical trials registration.
SETTING: This study enrolled patients undergoing an elective breast surgery. In particular, we enrolled patients who were scheduled for a mastectomy or quadrantectomy of the medial part of the breast.
METHODS: We recruited 40 patients who were scheduled for breast surgery. A PECS II block was performed with an injection of ropivacaine 0.5% 20 mL + 10 mL. Then, a PSB was performed by 2 separate injections of 3 mL of 0.5% ropivacaine, for each one, at the level of the second and fourth intercostal space. All of the patients received intraoperative sedation and multimodal analgesia. During the intraoperative period, the accessory need of a local anesthetic infiltration, conversion to GA, and the total amount of propofol required to maintain good comfort of the patients were recorded. In the first 24 postoperative hours, every 6 hours, postoperative pain was assessed by an investigator using a numerical rating scale (NRS). The consumption of analgesic and antiemetic drugs and the incidence of postoperative nausea and vomiting (PONV) were also recorded.
RESULTS: Our observational analysis yielded 40 patients in a period of 6 months. The population was subdivided into 2 groups: a mastectomy group or a quadrantectomy group. All of the population reported their pain scores at rest (rNRS < 3) and during activity (iNRS < 5) in the postoperative period. None of the patients required GA. Six patients (27.3%) in the mastectomy group required a supplemental anesthetic infiltration. Eleven (27.5%) patients required a rescue analgesic drug: 9 (40.9%) in the mastectomy group and 2 (11.1%) in the quadrantectomy group. Two patients reported events of PONV, one for each group (4.54% for the mastectomy group and 5.55% for the quadrantectomy group). No complications occurred.
CONCLUSION: This study indicates the safety and feasibility of the novel ultrasound-guided thoracic wall blocks during inpatient and outpatient breast surgery for the management of intraoperative anesthesia and postoperative analgesia.
LIMITATIONS: This is an observational study; a randomized control trial is mandatory to confirm the results.
Key words: Breast cancer surgery, pectoralis nerve block, parasternal block, ultrasound-guided anesthesia, regional anesthesia, pain control