The Ultrasound-guided Multiple-injection Costotransverse Block for Mastectomy and Primary Reconstructive Surgery. A Double Blind, Randomised, Placebo Controlled Trial.

Twelve women in Denmark are diagnosed with breast cancer every day. Breast cancer and ductal carcinoma in situ (DCIS) are the primary type of cancer/precursor to cancer in women, and one of the main treatment modalities is surgical intervention. DCIS is a non-invasive (pre-malignant) condition in the breast with proliferating cells with malignant characteristics; confined in situ by the basal lamina in the breast. International DCIS is considered as manifest breast cancer, but in Denmark DCIS is considered as a precursor to breast cancer.

Breast cancer and DCIS surgery includes many subtypes ranging from the minor lumpectomy to major surgery; e.g. mastectomy and reconstructive surgery with or without axillary clearance. All surgical subtypes at the Department of Plastic Surgery and Breast Surgery, Zealand University Hospital (ZUH) are performed under general anesthesia (GA) and implies a multimodal pain regimen with preoperative oral medication (Paracetamol 1g, Celecoxib (NSAIDs) 400mg, Gabapentin 600mg, Dexamethasone 8mg and Dextromethorphan 30mg). Standard GA is total intravenous anesthesia (TIVA) and consists of Remifentanil, Propofol (and Rocuronium for tracheal intubation if needed), and the anesthesiologists will administer IV Sufentanil (a synthetic long-lasting opioid) 0.3-0.5 microg/kg 20-30 minutes prior to emergence for the immediate postoperative pain treatment. The patients are given additional Sufentanil and/or morphine intravenously in the post anesthesia care unit (PACU), if necessary.

Depending of surgical subtype, the surgeons will sometimes inject local anesthetic (LA) during surgery. The anesthesiologists will infrequently (depending on the availability of technical skills on the day of surgery) perform ultrasound-guided (USG) nerve blocks (Pecs 1 (and or) 2 and serratus anterior blocks) in the anterolateral thoracic wall prior to surgery, but this is not an implemented standard treatment. It is sadly neither national nor European standard to use USG nerve blocks for perioperative pain management for breast cancer and DCIS surgery. Instead, the vast majority of surgical centers rely heavily on the use of various long-lasting opioids, despite the adverse events associated with these drugs. Only relatively few surgical centers in Europe have implemented TPVB or other USG nerve blocks in the anterior thoracic wall as standard treatment for perioperative pain management.

USG multiple-injection TPVB is considered the regional anesthesia golden standard for breast cancer and DCIS surgery and reduces both acute and chronic pain as well as postoperative opioid consumption.

To determine which surgical subtype would be the most relevant to investigate (define the quantity of the research problem) the research group at ZUH have conducted a thorough retrospective study (including 111 patients) regarding postoperative pain and 12- and 24-hrs opioid consumption concerning patients undergoing breast cancer and DCIS surgery during 2016-2017 at the Department of Plastic Surgery and Breast Surgery, ZUH. The electronic anesthesia files, PACU files and ward files were meticulously reviewed. Six surgical subgroups were reviewed and the UMPR surgery elicited high values on the numeric rating scale (NRS) and a substantial need for perioperative opioids. The survey revealed an overall accumulated morphine consumption in the first 24 postoperative hours of 86.1±60.1mg (mean ± SD) of oral morphine equivalents (OME) and a NRS in the PACU of 4.5±2.4 (mean ± SD) in UMPR patients - and this surgical subtype was selected as most relevant and feasible to investigate. This dosage should be evaluated in relation to the standardized multimodal regimen described above.