Brain Injury From Cardiac Surgery
Loss of brain function in the form of mild to severe cognitive impairment is a serious and potentially devastating complication associated with open-heart surgical procedures. While opinions on the rate of cognitive impairment related to cardiac surgery vary, memory problems, confusion and mental fogginess following surgery have been noted for as long as cardiac surgeries have been performed. A 1987 study reported 60% of patients undergoing coronary artery bypass graft (CABG) surgery suffered at least some cognitive impairment. Other studies indicate cognitive impairment occurrences following cardiac surgeries are between 11-75%. Physician negligence during surgery can contribute to impairment and associated brain injury.
Brain Damage from Bypass Surgery
Many speculate that the very machine that makes open-heart surgery possible may also contribute to the mild brain damage that may follow the surgery. During bypass surgery procedures, the patient’s aorta is clamped and a cardiopulmonary bypass pump (also known as a Heart-Lung Machine) is used to maintain the function of the heart and lung. The machine works by mechanically circulating and oxygenating blood outside the body (extracorporeally) while bypassing the lungs and heart, allowing surgeons to operate on a stopped heart.
The cardiopulmonary bypass machine may be used in numerous types of surgical procedures, including:
- Coronary artery bypass surgery
- Repair and/or replacement of aortic valve
- Repair and/or replacement of mitral valve
- Repair and/or replacement of tricuspid valve
- Repair and/or replacement of pulmonic valve
- Repair of aortic aneurysms
- Repair of atrial septal defect
- Repair of ventricular septal defect
- Repair of atrioventricular septal defect
- Pulmonary thromboendarterectomy
- Pulmonary thrombectomy
- Repair and/or palliation of congenital heart defects
- Heart transplantation
- Lung transplantation
- Heart-lung transplantations.
Brain Damage Related to Postperfusion Syndrome
Postperfusion syndrome (commonly referred to as "Pump head") is a neurocognitive deficit associated with bypass surgery and extracorporeal circulation (ECC). Brain damage can occur from a microembolism, either a particulate object or a tiny air bubble, that migrates from one part of the body to another through the circulatory system and causes a blockage (occlusion) in arteries, vessels or veins. Emboli can occur when the cardiopulmonary bypass pump produces toxic gases or tiny air bubbles, or when fat globules or bits of plastic debris enter the bloodstream of an anesthetized patient. Once in the bloodstream, emboli migrate to the patient’s brain where they can cause permanent damage and the resulting cognitive dysfunction.
To reduce brain damage from the extracorporeal circulation on the bypass pump, surgeons attempt to keep patients on bypass for as little time as possible. Several studies have indicated that increased time on the Heart-Lung Machine causes more severe cognitive dysfunction and increased risk of mortality.
Brain Damage Linked To Aortic Manipulation Surgical Technique
Brain damage from heart bypass surgery may also be caused by the way the aorta is handled by the cardiothoracic surgeon. Too much manipulation or handling can contribute to brain damage. A study published in the Journal of Thoracic and Cardiovascular Surgery in 2006 linked a common surgical technique to brain damage in CABG surgery patients. In the study, surgeons studied the effects of two separate aortic management protocols during bypass surgery, on the hypothesis that reducing manipulation to the aorta during bypass surgery would reduce the incidence of brain damage and cognitive defects.
The study involved consenting patients considered to be at high risk for brain damage in cardiac procedures– elderly patients, hypertensive patients, and diabetic patients. On one group of patients, surgeons utilized a multiple aortic clamping technique, the traditional approach, which has been associated with increased embolism activity. On a second group of patients, surgeons used a single aortic clamping technique, which reduced manipulation to the aorta during surgery and also reduced the risk of aortic tear. Six months post-surgery, patients in the second group had significantly less post-operative cognitive dysfunction. These findings question surgical techniques associated with aortic clamping and bypass machines and offer potential solutions for reducing cognitive deficits associated with cardiac surgery in the future.
For more information, or to discuss your situation with a brain injury attorney at The Brain Injury Legal Help Center, call (800) 610-1892.