Fern, Dr Sanders website explains it better than I can. I know that when he did the block on my pec minor as a test......my symptoms improved dramatically. http://http://www.ecentral.com/members/rsanders/
"If following a pectoralis minor block there is significant improvement within a few minutes, we have been performing a very simple operation called pectoralis minor tenotomy. This operation is performed through a 3 inch incision in the arm pit. The pectoralis minor muscle is easily found and cut at its attachment to the shoulder blade (at the coracoid process). One inch of the muscle is then removed to prevent it's reattachment to the top of the nerves going to the arm. The incision is closed with buried stitches. The operation usually takes less than 30 minutes and can be performed as an outpatient and recently we have found that this procedure can be performed under local anesthesia, but with an anesthesiologist in attendance so that patients are asleep for a short time but are awake within a few minutes of the end of the operation. The procedure carries almost no risk of injury."


Hope this helps!