An Endo in Sight for Abdominal Aortic Aneurysms
Date: July 1, 2009
Clarence Blackwell awoke one morning feeling fatigued and nauseated, and soon began vomiting. Over the past several years, the 77-year-old had had six vessel heart bypass procedures with 20 percent residual function of his heart (EF 20-25 percent). He had significant heart ischemia (positive stress test) but was not deemed a candidate for further coronary revascularization. He also had significant renal insufficiency (cr 2.6 and GFR 26 cc/min). Unwilling to take any chances, Blackwell’s wife insisted he go to an ER, though she thought he might only be having an appendix problem.
Her determination likely saved Blackwell’s life, says Mahmoud Malas, chief of endovascular surgery at Johns Hopkins Bayview Medical Center, where emergency department physicians quickly identified a
large, leaking abdominal aortic aneurysm. Several years ago, the traditional open procedures done to repair an AAA, Malas says, “would’ve put significant stress on the heart of someone who’s had severe coronary disease.” If he survived the operation, he might face respiratory failure or pneumonia and ileus as complications.
Today, endovascular repair is performed routinely for these types of patients. But, says Malas, just because these repairs have become more common doesn’t make them less risky. People with heart problems are compromised already, he notes. When you have someone like Blackwell with kidney problems too, an endovascular procedure gets even dicier. “Like a lot of patients,” Malas says, “he also had a challenging anatomy, which makes it difficult to navigate the endograft devices.”
Malas performed the emergency endovascular repair using a CO2 angiogram to avoid the large amounts of contrast medium that would be required to show the anatomy of the aorta and iliac arteries. Though CO2 doesn’t offer as precise a visual as the usual contrast media, it’s safer for patients with compromised kidneys. Malas also uses the most recent generation of endografts, which, he explains, “have become much more flexible and, in skilled hands, make it safer for patients with tortuous anatomies.”
Blackwell’s operation required only a small incision through his groin and an overnight hospital stay. The next day he was walking around, and a short time later he was back to his regular routine. Endovascular procedures, says Malas, are still evolving and improving, and Johns Hopkins is participating in a number of clinical trials that are looking at better devices that can improve outcomes.
One of the biggest challenges is that there often are anatomical difficulties like Blackwell’s that make navigation for endovascular procedures prohibitive. In one trial, Malas and others are working with the next generation of devices, flexible endografts that are designed to conform to a patient’s anatomy.
“We’re also performing endovascular repair of thoracic aortic aneurysm with remarkable results” he says.