Clinical study

The MIC block

  • Research area: Regional blockade

  • Primary investigator: Martin Vedel Nielsen

A randomized, placebo-controlled, and double-blind study, comparing the effect of the ultrasound-guided multiple-injection costotransverse block vs. placebo. 

We have developed a novel ultrasound-guided nerve block indicated primarily for breast cancer surgery that mimics a thoracic paravertebral block (TPVB) – hitherto the internationally accepted regional anesthesia golden standard for anesthesia of the hemithorax – but hypothetically without the risks of adverse events associated with the TPVB (e.g. pneumothorax, risk of bleeding in the thoracic paravertebral space, random and unmanageable epidural spread, etc.). We have already tested the anatomical- and block execution hypothesis in a randomized cadaveric study, and we now have anatomical proof of concept for the functionality of the block technique. We have also conducted a small clinical pilot study with very promising results. We need clinical proof of the efficacy of the new block modality and therefore we have launched this randomized, placebo-controlled, and double-blind study, comparing the effect of the ultrasound-guided multiple-injection costotransverse block (MICB) vs. placebo.

The aim is to investigate the efficacy of the MICB vs. placebo in patients undergoing unilateral mastectomy and primary reconstructive surgery due to breast cancer or ductal carcinoma in situ. The hypothesis is, that the unilateral MICB will significantly reduce the opioid consumption during the first 24 postoperative hours and significantly reduce the Numerical Rating Scale pain score (0-10) and opioid-related side effects.

Oral preoperative medicine is Acetaminophen 1g, NSAIDs (celecoxib) 400mg, Gabapentin 600mg, Dexamethasone 8mg and Dextromethorphan 30mg. In the active group, the treatment will be three injections of each 10ml of Ropivacaine 5mg/ml. In the placebo group, the treatment will be three injections of each 10ml of Sodium chloride 9mg/ml. The three injections are targeting superficial to the superior costotransverse ligament (superior to the thoracic spinal nerve T2, T4, and T6 respectively). Postoperative the patients are given a PCA pump with morphine. The follow-up time is 24 hrs., 14 days, and 1 year.

MICB MRI

Pain treatment in the perioperative period following major breast cancer surgery is inconsistent worldwide. Regional anesthetic modalities such as the thoracic paravertebral block exhibit superior pain amelioration and can both decrease the neuroendocrine surgical stress response and decrease the incidence of chronic postoperative pain. However, the thoracic paravertebral block is not routinely adopted due to the inherent risk profile (e.g. pneumothorax). We have developed a new ultrasound-guided block modality “the multiple-injection costotransverse block” which combines the positive mechanism of action from the thoracic paravertebral block with a highly reduced risk profile. We hope that this block will be a turning point for future breast cancer patients.

We aim to further enhance patient safety and comfort by comparing the multiple-injection costotransverse block (3 injections) with a single-injection costotransverse block in a prospective, blinded, randomized, cross-over magnetic resonance imaging study. We hope to demonstrate that a single injection is equivalent to multiple-injection in terms of the spread of local anesthetic.

A very small dose of Dotarem (Gadoteric Acid) will be added to standard local anesthetic (Lidocaine) and healthy volunteers will be randomized to either block modality. Magnetic resonance imaging will be conducted followed by dermatomal mapping. The process is repeated 14 days later, but with the other block modality on the contralateral side.

https://clinicaltrials.gov/ct2/show/NCT04248179