Advanced Techniques for Aortic Dissection/Aortic Aneurysms
MADISON - One patient presents with deep, throbbing chest pain and shortness of breath. The other presents with deep throbbing chest pain and shortness of breath. But misdiagnosing an aortic dissection or an aortic aneurysm as a heart attack can have debilitating and deadly ramifications for a patient.
That's why it's critical for primary care physicians to not just understand the critical differences between these distinct - and distinctly dangerous - vascular events, but also to involve specialists who know how to treat them and limit their impact.
Vascular surgeons and cardiac surgeons at the University of Wisconsin Hospital and Clinics in Madison are key players in the management of these complex vascular catastrophes.
Between 9,000-10,000 patients each year suffer an aortic dissection, a tear in the inner wall of the aortic artery that creates a parallel channel of blood flow, placing pressure on the artery wall and potentially causing a reversal in blood flow back towards the heart or rupturing in the chest.
Time is Critical for Aortic Dissections
Most dissections occur spontaneously, although patients with difficult to control hypertension and Marfan's syndrome are much more likely to experience one. On a historical note, the actor John Ritter died of aortic dissection, and King George II, the monarch who occupied the British throne during the American Revolution, may have died of one as well.
In these cases, time is of the absolute essence - the mortality rate for unrecognized aortic dissection may be as high as 75 percent over the first 24 hours in cases of missed diagnosis.
"Most of the time, patients come in with excruciating chest pain or back pain, so the first thing a physician is likely to think is that this person is having a heart attack," says Girma Tefera, MD, a vascular surgeon with UW Hospital and Clinics who specializes in aortic aneurysm care. "In fact, in patients who survived dissection, up to 35 percent of the time, aortic dissection was not the first diagnosis in the emergency department."
Abdominal Aortic Aneurysm
Abdominal aortic aneurysm (AAA) is the most common type of aneurysm in humans. While it's usually an asymptomatic condition, ruptured AAA represents the 10th leading cause of death in the United States. Only half of patients experiencing an aortic rupture make it to the hospital - and of those who do, 50 percent will die after surgery. National statistics indicate that the overall mortality for AAA adds up to 75-80 percent.
Since 2007, patients who are at high risk for AAA are allowed to have ultrasound screening as their initial enrollment physical examination under Medicare.
"Primary care physicians should take advantage of this free screening to identify patients with AAA," says Dr. Tefera. "Patients who are hypertensive, male or have a family history of aneurysms should be screened."
Imaging and Treatment Techniques for Aneurysms/Dissections
For the emergency room or primary care physician who encounters a patient complaining of severe chest pain or inter-scapular back pain in the presence of an uncontrolled blood pressure with or without blood pressure discrepancy in the upper extremities, an aortic dissection should be the first diagnosis until proven otherwise. A CT scan of the chest and abdomen with contrast is the imaging modality of choice. This imaging modality can generally reveal both the size and location of the dissection. The size and location of the aneurysm or dissection will determine the next course of action.
The immediate care for dissection involves getting control of the patient's blood pressure and heart rate through the use of beta blockers and vasodilators. Emergency surgery is usually needed for type A dissections or for complicated type B dissection. These complications of type B dissection include organ ischemia (renal or Mesenteric) or lower extremity ischemia due to occlusion from dissection. Physicians should note that this might be the only initial presentation.
The vascular surgeons and the team of cardiothoracic surgeons at UW Hospital and Clinics are fully trained in the range of surgical interventions for dissections and aneurysms, from valve repairs to artery grafts and bypasses that can re-route blood flow and restore limb function. Currently, physicians are exploring the possibility of developing minimally invasive treatments for aneurysms and dissections.
"Both of these clinical scenarios carry a very high risk of death and high index of suspicion," says Dr. Tefera. "Prompt imaging modality with CT scan of ultrasound followed by urgent surgical attention can be life-saving."
For more information about the vascular surgery program at UW Hospital and Clinics, as well as free aneurysm screening opportunities through the vascular surgery clinic, call (608) 263-8915.
Date published: 4/28/2008