November 26, 2010

I would like to share with you some unique perspectives on a number of chronic pain syndromes.

Tom was 68 years old when he started having chest pains. His family doctor suspected “angina” (pain coming from the heart) and sent him to a cardiologist who ordered a number of tests. At the end, Tom was told that he had a couple of “blocked” arteries in his heart and his best bet was a “bypass” surgery. Tom went for it, as the chest pains had become debilitating and he was not responding to medications.

After the surgery, the cardiac surgeon told him that all had gone smoothly without complications. But Tom did not feel well. The angina pain had been replaced by a new kind of intense and bizarre pain on the left side of his chest. Originally, he thought it was pain due to the surgery (which involves splitting the chest bone in two to gain access to the heart), he thought that as he healed, it would go away.

Unfortunately, the pain in his chest remained severe. To make matters worse, the left side of his chest had become so sensitive that he could not stand the pain caused by his shirt or even water touching the area while in the shower.

Tom suffered from what I named “Internal Mammary or Internal Thoracic Artery” syndrome. I first wrote about this syndrome in a scientific journal in 1989, I had seen many patients coming to my clinic with strange chest pain after bypass surgery. One woman came wearing a huge fur coat in the middle of the hard Canadian winter. She opened it up show me that underneath… she wore nothing (because she could not tolerate the contact of her clothes). Another patient even came wearing a bedsheet! She had cut a hole for her head and her arms and underneath she carried a pack of fluffed cotton, so that her skin did not touch anything. Later on in the summer, a man came to my office without a shirt, he bitterly complained that he could not even tolerate the draft of the wind blowing over his chest hair (which had been shaved for the surgery and was growing back).

All these patients had undergone heart bypass surgery and they all had an area in the left side of the chest where the skin was extremely sensitive to touch. Yet, they could not feel the coldness of an ice cube. Others had patches of insensitive skin in the same area. Almost all suffered from jabs of burning and shooting pain.

I ran to my cardiac surgeons. “What exactly did you do during this procedure?” I asked, trying to understand the details of the surgery, as heart bypass had been around for many years, but this was the first time I was seeing such a group of patients. I was sure that the surgeons had damaged some little nerves in the front of the chest wall, as the symptoms my patients described were classic for neuropathic pain (extreme sensitivity to touch, bizarre electrical shocks etc). The mystery was soon solved…

It was only recently that the surgeons in my hospital had started using a “modification” for the bypass surgery. Usually, the “tube” they use to bypass (replace) the clogged heart artery, comes from a leg vein. However, the new procedure which was quicker and easier and had much better long term results, involved the use of a tiny artery (called Internal Mammary or Thoracic Artery) that was already connected to the large artery that goes to the heart.

My surgical colleague, Dr. Chris Feindell and I were sure that something during the “harvesting” of this tiny artery was responsible for what seemed to be damage to the “anterior intercostal” nerves of the chest. Later, my colleague worked with his students to modify the procedure, so lately, I have seen very few such patients referred to me by my surgeon in my hospital. However, I still see them arriving in my clinic if operated in other hospitals.

The syndrome is now known around the world as a cause of chest pain after surgery, as surgeons still use the older procedure. I did another study of this condition some eleven years later. We were able to determine that nerve damage occurs in ¾ of all patients submitted to heart bypass surgery with the use of Internal Mammary/ Thoracic Artery, but that only 15% of those with nerve damage will experience pain. Unfortunately, these are still very big numbers when one thinks of the thousands of such procedures performed annually around the world.
Although it has been 21 years since I first wrote about this syndrome, Doctors still know very little about it. Patients are mistakenly submitted to cardiac investigations and think they still suffer from heart-related pain. The pain varies from mild to severe and may last a year or indefinitely (though in my experience it gets much better with time). Certain drug treatments for neuropathic pain (gabapentin, pregabalin etc.), local modalities such as TENS (which however is contraindicated for patients with pacemakers) or deep heat (laser or ultrasound) and painkillers, help. For more information on the syndrome, check www.actionontario.ca
Click on the Neuropathic Pain/ background tab and look at the brochure for Neuropathic Pain at the very bottom.

In the photo below, a patient of mine who suffered from the syndrome wanted to return back to work. In order to avoid the contact of his shirt with his very sensitive skin, he “invented” a frame he hung around his neck! No one ever suspected anything when he returned to work wearing his shirt and tie. Luckily, his sensitivity got much better in 2 years and he got rid of the frame.

Angela Mailis Gagnon, MD, MSc, FRCPC(PhysMed)
Director, Comprehensive Pain Program,
Senior Investigator, Krembil Neuroscience Centre
Toronto Western Hospital,
www.drangelamailis.com
Chair ACTION Ontario www.actionontario.ca