Intraoperative angio should be used in all brain aneurysm procedures

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Intraoperative angiography (IA) is safe and can be performed without significantly prolonging intracranial aneurysm procedures, according to a study that Eric Nussbaum, MD, will present tomorrow at the American Association of Neurological Surgeons (AANS) conference in Chicago.

Nussbaum, MD, chair of the National Brain Aneurysm Center (formerly the HealthEast Neurovascular Institute) in St. Paul, Minn., and colleagues performed IA in 1,025 cases of microsurgery for intracranial aneurysm between July 1997 and June 2006.

Nussbaum told Health Imaging News that “intraoperative angiography has been around for many years,” and yet questions still remain about its efficacy, which have caused certain surgeons to hesitate in using IA, especially in smaller centers and hospitals.

However, out of the 1,025 cases in the study, the researchers reported no major complications; five femoral artery pseudoaneurysms, one of which required open repair; two carotid, one of which required vertebral artery dissections, but all were asymptomatic, not flow-limiting; and five cases were aborted due to access issues.

Out of the 1,025 cases in this study, the researchers reported no major complications; five femoral artery pseudoaneurysms, one of which required open repair; two carotid, one of which required vertebral artery dissections, but all were asymptomatic, not flow-limiting; and five cases were aborted due to access issues.

The researchers also noted that in 1997, IA added a mean 28.5 minutes to the surgical procedure (including sheath insertion). However, by 2006, IA added only 10.5 minutes to procedure at the National Brain Aneurysm Center.

Nussbaum and colleagues also found that out of the 1,025 cases, IA resulted in clip repositioning or additional clip placement in 96 cases (9.4 percent), with 64 cases of residual, treatable aneurysm and 32 cases of vascular stenosis. They also found that IA demonstrated unexpected aneurysm obliteration in 42 cases when surgeon suspected additional clip placement needed.
 
The investigators stressed that IA is critical because they encountered 30 cases (2.9 percent) in which IA demonstrated completely unexpected, treatable, residual aneurysm or vascular stenosis; and careful re-examination of vascular anatomy disclosed fundamental misinterpretation by surgeon of local anatomy.

Nussbaum told Health Imaging News the long-standing reluctance toward accepting IA seems to focus on four factors:
  • Some surgeons still question whether IA would make a difference;
  • Some surgeons still believe that there will be a lot of complications associated with using IA;
  • Some surgeons question if IA will prolong the procedures and therefore, increase the infection rate; and
  • Finally, surgeons question the availability of having a neuroradiologist or neurosurgeon, who can perform angiographies, on stand-by for the operating room.
Nussbaum pointed that the final factor “has been prohibitive in a lot of smaller hospitals and centers that haven’t adopted a dedicated approach.”

He noted that angiography does have stroke as a potential risk, and “if it’s not done in the cath lab under the most optimal circumstances,” people tend to question its effectiveness. However, “our results with such a large patient population and almost no complications will set to rest some of those concerns, especially when you have highly-skilled people performing the procedure,” Nussbaum said.

Nussbaum acknowledged that “there is a learning curve for both the radiologist and the techs, who are using the angiogram machine and equipment. But…after you’ve done a few of these, the time that it adds to procedure is really negligible.”

“We have an unstated bias in our institution that brain aneurysm should be treated at high-volume centers,” noted Nussbaum. “In this field, we have witnessed fewer surgeons and centers operating on a growing number of aneurysm…and [with recent developments] we should begin expecting a higher standard in treating brain aneurysms,” he elaborated.

For instance, at National Brain Aneurysm Center is able to perform a successful intracranial aneurysm procedure using IA in one and a half to two hours; however, there are a lot of centers, which perform procedures less frequently, and it can take four to six hours.

“I’m hoping that studies like ours, which demonstrate that a readily available adjunctive technique can change the outcomes for patients. The study might also drive home the question—is it really appropriate for a surgeon in a smaller hospital who does three to four a year, to perform aneurysm surgery, or should they be referring it to a higher volume center, where you can have a dedicated approach,” he said, in reference to the potential effects of the study.

“High-volume centers have the luxury of performing procedures, like routine intraoperative angiography which will benefit the patient,” he stressed.

Nussbaum said that his center will continue to use IA in every patient. “The use of IA in all of our intracranial aneurysm surgeries gives us a deeper sense of assurance that we have completely corrected the problem, and that we have taken every step possible to ensure our patients' safety,” he said.