Heart bypass surgery is a major operation with the potential for many complications. While these complications are rare and thousands of bypass surgeries are done each year, diabetics, because of their diminished immune response and microvascular disease, may have a higher risk of complications.
Chest Wall Infection
Chest wall infection is a concern in the diabetic patient. Diabetes impairs the immune function and affects the small blood vessels of the body. Diabetics who have poorly controlled sugars are at particularly high risk of infection secondary to vascular disease. In heart surgery, the chest wall is opened with a lengthy incision and muscles are cut away from the breast bone. The sternum is subsequently cut in half in a lengthwise fashion in order to access the heart. The chest wall on the left side is then dissected to free the left internal mammary artery for use on the heart. By disrupting the blood flow to the chest wall, diabetics with already impaired perfusion may have an increased risk of chest wall infection. Chest wound infection can be life threatening and may require the removal of the sternum in order to rid the body of the infection. Occasionally, if the infection does not respond to long-term antibiotics, the sternum must be removed.
Kidney Damage
Patients with diabetes are at an even greater risk for kidney damage after bypass. Diabetes causes tiny capillary damage to the kidneys, and most diabetics have some kidney damage or impairment. Diabetics who undergo bypass surgery with the heart-lung machine are at potentially greater risk for kidney failure. The heart-lung machine produces an inflammatory response throughout the body that releases cytokines into the blood stream. These small proteins travel to various organs and can cause organ damage or failure. Kidneys that have already been impaired due to diabetes may not tolerate the additional insult of the cytokines.
Atrial Fibrillation
Atrial fibrillation is a common arrhythmia that occurs in 15 to 40 percent of heart bypass patients, according to the Merck Manual. In a "MedPage Today" article published in September 2009, a reported study shows that atrial fibrillation was 44 percent more prevalent and 38 percent more likely to occur in diabetic patients. Atrial fibrillation is a chaotic contraction of the atrium that can become very rapid and cause fatally low blood pressure. Diabetic patients undergoing bypass surgery have a higher risk for atrial fibrillation.
References
- American Diabetes Association.org: Diabetes and the risk of infection related mortality
- BiomedCentral. Superficial and Deep Sternal Wound Infection after more than 9000 coronary artery bypass grafts, incidence, risk factors and mortality. Abbas Salehi Omran, MD and et.al. BMC Infectious Disease. 2007
- MerckManualOnline.com: Coronary Artery Bypass Grafting (CABG)
- National Institutes of Medicine.gove: Diabetic Kidney Problems
- MedPage Today.com: Arrhythmia, Diabetes Linked in Women.
