Ultrasound Guidance Lowers Risks of Thoracic Nerve Block Technique for Mastectomy

Ultrasound-guided thoracic paravertebral nerve block (TPVB) is highly effective in controlling pain after breast cancer surgery and lowers the risk of complications, according to a study published in the journal Anesthesia & Analgesia.

Previous reports have suggested that performing this nerve block under ultrasound guidance might make the procedure safer. The current study is the first to provide evidence that ultrasound-guided nerve blocking lowers the risks of pleural puncture and pneumothorax.

This regional nerve block provides excellent control of pain after breast cancer surgery. That’s especially important because pain in the immediate postoperative period is a major risk factor for the development of chronic pain in women who have undergone mastectomy.

However, this nerve blocking isn’t performed as often as it might be because of patient safety concerns — especially the risk of puncturing the pleura due to incorrect needle placement. This can lead to a serious complication called pneumothorax, where air enters the chest cavity, potentially causing collapse of the lung.

Peter Stefanovich, MD, Massachusetts General Hospital, Boston, Massachusetts, and colleagues analysed their experience with ultrasound guidance to make this nerve blocking safer. Using ultrasound, the anaesthesiologists performing nerve blocking were able to visualise the exact location of the thoracic spinal nerve roots. Ultrasound was used in addition to the conventional approach, using anatomical landmarks to guide the injection.

Following this procedure, anaesthesiologists were able to confirm correct needle placement before injecting the local anaesthetic. In the experience of more than 14,000 thoracic spinal nerve injections, there were no pleural punctures and no cases of pneumothorax.

Major complications related to this nerve blocking placement developed in 6 patients — a rate of 0.70%. Four patients had drops in blood pressure and heart rate, while 2 had suspected toxic effects of the local anaesthetic used for the procedure.

“Avoidance of these complications may be a consequence of improved safety using real-time visualisation and imaging of the pleura with ultrasound,” the authors wrote.

They hope their experience will encourage other hospitals to offer this highly effective regional anaesthesia technique, potentially reducing the common and difficult-to-treat problem of chronic pain after mastectomy.