The Cedars-Sinai Specialist Aortic Service and Acute Aortic Dissection
Mar 15, 2021 Joanna Chikwe, MD
Acute aortic dissection is a pathological catastrophe that is frequently fatal. The most common form is also the most lethal, affecting the ascending aorta and classified as Type A. Lifesaving emergency surgery is indicated in almost all cases.
Although once considered an operation that should be in the remit of any qualified cardiac surgeon, it remains one of the highest-risk procedures. The best results are achieved in centers that provide a specialized aortic service. Cedars-Sinai has developed such a service—the Cedars-Sinai Specialist Aortic Service (CSSAS). It goes beyond the expertise of the individual cardiac surgeons who provide the dedicated on-call rotation for aortic dissection. CSSAC is comprised of highly specialized anesthesiologists, perfusionists, intensivists, cardiologists and vascular surgeons.
"Even better than waiting to diagnose an aortic dissection is preventing it. This is where the Cedars-Sinai Specialist Aortic Service Clinic comes in."
Type A Aortic Dissection
The emergency procedure to repair a Type A aortic dissection is very complex and challenging. It involves systemic cooling of the patient to reduce their metabolic rate, and periods of interruption of the circulation to most of the body’s organs. In a condition, by its very nature, it disrupts the circulation to these organs. Detailed attention to the conduct of cardiopulmonary bypass is critical to avoid malperfusion syndromes. An experienced team is vital to this lifesaving procedure, allowing for successful repair of the aorta while avoiding the dreaded complications of stroke, myocardial infarction or spinal cord ischemia. In surgery for Type A aortic dissection it does not suffice to be prepared for Plan A. The team must know when to switch to Plan B, and be able to deliver that competently, as well as potentially Plans C or D.
The immediate goal of surgery is, of course, to save the patient’s life, but the Smidt Heart Institute service has the capacity to look beyond the immediate situation. Improved early and long-term outcomes are proven with continued selective cerebral perfusion, aortic valve-sparing root replacement, and extension of the aortic repair distally into the arch with a frozen elephant trunk or other endovascular stent.
Preservation of the native aortic valve, as well as more directed surgical obliteration of the distal false lumen, are particularly important issues for young patients. All these possibilities require a specialized aorto-vascular surgeon. Monitoring of cerebral blood flow by infrared spectroscopy and continuous analysis of spinal cord function with motor-evoked potentials are important in having a zero-tolerance for neurological injury, and require anesthesia and neurophysiologists experienced in these techniques.
Type B Aortic Dissection
The other main type of aortic dissection is Type B. Management of this requires careful consideration of the role of endovascular stenting. Although initially many patients may be managed conservatively, there is increasing evidence that early intervention with endovascular stenting improves aortic remodeling and leads to eventual aortic healing. Rarely, open surgery is required. The CSSAC provides the full range of expertise to serve every patient.
Prevention as a First Defense Against Aortic Dissection
Even better than waiting to diagnose an aortic dissection is preventing it. This is where the Cedars-Sinai Specialist Aortic Service Clinic comes in. Patients who might be at risk of developing aortic dissection are assessed by a multidisciplinary team of cardiac and vascular surgeons, cardiologists and radiologists who use advanced imaging techniques in cross-sectional imaging—including volumetric analysis and compliance measurement—to predict an individual patient’s risk and advise patients on the best time to undergo prophylactic surgery.
Typically, these are patients with existing or previous aneurysms of the aorta, or who may be known to have a familial aortopathy. Where intervention is not required, the CSSAS Clinic keeps the patients under surveillance with cross-sectional imaging. The clinic will share the plan of care with referring cardiologists, who usually keep overall control of the patient and maintain the echo imaging side of surveillance. Our aortopathy cardiologist also runs a screening service to identify genetic aortopathies and counsels patients accordingly.
Sadly, aortic dissection still kills more Americans than road traffic accidents. Half of patients die before reaching the hospital. Tragically, half of the patients who do reach the hospital also die, most without undergoing the potentially lifesaving emergency surgery described above. Our team at the Smidt Heart Institute is dedicated to improving the treatments and outcomes in our aortic patients.