Hybrid TAAA Repair Shows Promise In Small Study

By Mitchell L. Zoler  

PHILADELPHIA -- A hybrid strategy for repairing thoracoabdominal aortic aneurysms was generally successful when used on 11 patients at a single center, according to a chart review of 16 patients treated.

Although the number of patients who have gone through the complete hybrid procedure is small, this is still one of the largest single-center series of hybrid repair for thoracoabdominal aortic aneurysms (TAAA), Dr. Michael P. Brown said during a session of the Peripheral Vascular Surgery Society at the Vascular Annual Meeting.

The first surgical step involves debranching of the abdominal aorta by visceral revascularization of the celiac, superior mesenteric, and renal arteries. The second step (performed as a separate procedure, ranging 6-99 days later) is endovascular exclusion of the aneurysm using commercially available stent grafts. This alternative to conventional, open repair of a TAAA is an option for older patients who have a relatively good risk profile for surgery or for younger patients who have a poor risk profile for open surgery, Dr. Brown said.

None of the patients developed neurologic complications or symptoms of spinal-cord ischemia after either stage of the hybrid procedure. Historically, 5%-15% of patients undergoing TAAA repair have spinal cord ischemia and subsequent neurologic damage.

"We think that open repair plus aortic cross clamping leads to spinal-cord ischemic insults," said Dr. Brown, a vascular surgeon at the University of Florida in Gainesville.

The senior surgeon from this series suggested that the hybrid approach avoids spinal-cord ischemia by not producing an anatomic cessation of blood flow to the spine. Hypotension often occurs in patients undergoing TAAA repair, and "when you combine anatomic cessation of blood flow to the spinal cord on top of hypotension, it's a really bad combination," said Dr. W. Anthony Lee, a vascular surgeon at the University of Florida and collaborator with Dr. Brown.

So far, 16 patients were scheduled for the hybrid repair and proceeded through the initial revascularization stage during May 2005-May 2006. Of these, 11 patients went on to have the second stage done, 2 patients died following the first stage, and 3 patients were awaiting their second-stage procedure; 1 of these patients will not have the second stage done because of lingering complications from the first stage. No patient has had an aneurysm rupture while awaiting the second-stage repair.

The first stage is usually long, technically challenging, and physically stressful for the patients, said Dr. Brown. A total of five patients had major complications following the first stage. The median hospital length of stay following the first stage was 8 days, with a range of 1-45 days. Further investigation must be done into the short- and long-term outcomes, said the researchers.