Emergency Repair of Ruptured AAA Uses Balloon Technique

BY TIMOTHY F. KIRN

SCOTTSDALE, ARIZ. -- Emergency endovascular repair of a ruptured abdominal aortic aneurysm is possible, even when the patient is in shock and rapid aortic clamping is necessary, Dr. Martin Malina said at an international congress on endovascular interventions sponsored by the Arizona Heart Foundation.

The technique involves using a series of balloon clamps in the aorta and then iliac vessels. Of 62 such patients treated at his institution, only 18 deaths occurred, said Dr. Malina, of the department of vascular surgery, Malmö (Sweden) University Hospital.

This result suggests that the technique compares well with the open approach, in which mortality tends to be around 40%, he said. "I think with little tricks like this, vascular surgery is more and more turning toward the endovascular approach,"

The technique involves advancing a balloon catheter from the femoral artery into the aorta and deploying the balloon above the renal arteries. The balloon sheath needs to be large and long enough to support the balloon, so that the restored pressure does not push the balloon out of place, Dr. Malina said.

The stent graft is then advanced from the ipsilateral groin and deployed distal to the balloon. Next, a second balloon is advanced and inflated inside the graft below the renal arteries, to replace the suprarenal balloon and to minimize the suprarenal cross-clamping time.

The suprarenal clamping time is generally not longer than 20-30 minutes, "which is quite acceptable," Dr. Malina said.

The sheath that was used to deploy the first balloon allows it to be retrieved, and Dr. Malina said he chooses to use grafts with barbs or hooks so the graft does not become displaced as the sheath is retracted.

After the main graft has been deployed, the iliac extensions can be placed, with balloons inside them to allow for inflation and deflation in a staged declamping that will avoid a sudden drop in pressure.

"Does that mean you should always use bifurcated stent grafts for ruptured aneurysms?" Dr. Malina said. "I don't think so. I think you have to assess the condition of the patient and the anatomy. Balloon occlusion of the aorta in ruptured aneurysms and in patients who are in shock seems to be rather quick and simple."

When asked to comment on this presentation for VASCULAR SPECIALIST, Dr. Frank Pomposelli, associate professor of surgery at Harvard Medical School, stated: "This study adds further evidence to an expanding body of evidence that endovascular repair of ruptured AAA is not only feasible but can be applied to unstable patients--a critical point if it is to become applicable to a larger population of patients with this lethal complication of aortic aneurysm.

"The use of intraluminal balloon occlusion to decrease hemorrhage and stabilize the patient is not a new concept in the treatment of ruptured AAA. A similar technique in which deployment is performed proximally from the brachial artery has previously been described.

"The limitations of endovascular repair for ruptured AAA are many. The anatomic features of the aneurysm may be unsuitable for endovascular repair in as many as 50% of patients presenting with rupture. Logistical problems such as the expense of maintaining an inventory of devices, lack of availability of trained surgical, nursing, technical staff and facilities "24/7" are significant impediments to be overcome before this approach can be widely applied. Moreover, while these results are excellent, by definition, they are inherently biased, since only certain patients can be treated, making comparison to previous studies of open repair of ruptured AAA inappropriate.

"Nonetheless, endovascular repair of ruptured AAA appears to be a significant treatment advance where the expected mortality has traditionally been 50% or higher with open surgery. As experience grows, new devices are developed and more surgeons and their support staffs gain expertise with endovascular AAA repair, it may well become the treatment of choice for many patients."