Prophylactic Transluminal Balloon Angioplasty Cuts Aneurysmal Vasospasm
SAN FRANCISCO—Prophylactic transluminal balloon angioplasty reduces the incidence of vasospasm after a ruptured brain aneurysm, researchers reported here at the 2007 International Stroke Conference sponsored by the American Stroke Association in February. The balloon angioplasty is typically done after the aneurysm clipping and is intended to keep postsurgical vasospasm down.
Despite fewer episodes of vasospasm, however, the overall outcome with prophylactic balloon angioplasty was not significantly different than that of usual drug-therapy care, said Jan Paul Muizelaar, MD, PhD, professor of neurological surgery at the University of California-Davis.
On the other hand, patients who received the prophylactic procedure soon after the hemorrhage were less likely to need an emergency balloon angioplasty later, he reported. Additionally, angioplasty did improve neurological outcomes in patients who were in better clinical condition.
“By selecting patients who are not severely affected, we may improve outcomes, although further study is needed to confirm this,” Dr. Muizelaar said at a late-breaking session.
According to Dr. Muizelaar, aneurysmal vasospasm occurs in about 30 percent of patients who have a substantial bleed. It usually occurs three to 14 days after the first hemorrhage and can lead to a secondary ischemic stroke.
“So far, drug therapy has been disappointing,” Dr. Muizelaar said, leading researchers to seek mechanical treatments.
Based on favorable results from a pilot trial of patients with Fisher Grade 3 subarachnoid hemorrhage treated with transluminal balloon angioplasty before the onset of vasospasm, the investigators designed the current 10-center trial. [The Fisher grading scale ranges from 0 — for no clot — to 4, indicating an intraventricular or intraparenchymal hemorrhage. A score of 3, which indicates a localized clot or diffusely distributed hemorrhage greater than or equal to 1 mm in thickness, carries the greatest risk of subsequent vasospasm.]
In the study, 170 patients “at high risk for vasospasm, as measured by the amount of blood around the arteries on CT,” were randomly assigned to prophylactic transluminal balloon angioplasty plus standard care or standard care alone, he said.
All the patients had Fisher Grade 3 subarachnoid hemorrhages with aneurysms satisfactorily secured by clipping or endovascular coiling within 72 hours.
Results showed that 23.5 percent of patients who had transluminal balloon angioplasty developed symptomatic vasospasm, compared with 31.8 percent in the standard drug therapy group, a significant difference.
Additionally, only 11.8 percent of patients who had prophylactic transluminal balloon angioplasty needed therapeutic angioplasty versus 25.9 percent of those in the standard care group.
“This showed proof of principle. There was indeed less vasospasm and also significantly fewer patients needed therapeutic ballooning,” Dr. Muizelaar said.
However, there was no significant difference in neurological outcome of the two groups at three-month follow-up. Specifically, 49.4 percent of those who had balloon angioplasty had favorable outcomes, as reflected by scores of 4 to 5 points on the 5-point Glasgow Outcome Stroke Scale versus 43.5 percent of those in the control arm. (A score of 1 indicates death; 4 indicates a moderate disability; 5, a good recovery.)
When they considered only patients with less severe strokes, however, those who had balloon angioplasty had more favorable outcomes than those who had standard care: 77.2 percent of patients who had angioplasty scored 4 or 5 on the Glasgow Stroke Scale, compared with 67.7 percent of those who did not have the procedure, another significant difference.
This is an important group to target, Dr. Muizelaar said, as many patients arrive at the hospital in good clinical condition with no neurological deficits. “Yet one-third end up dead or severely disabled. We believe that prophylactic ballooning can prevent vasospasm, and in patients who are not severely injured by their initial hemorrhage, it may improve neurological outcome.”
‘AN EXCITING APPROACH’
Philip B. Gorelick, MD, chief of the department of neurology and rehabilitation at the University of Illinois at Chicago, said that patients who have a hemorrhagic stroke are subject to a double insult.
“The blood vessel rupture can prevent blood from getting to brain tissues causing death of tissue. In addition, the presence of blood can irritate arteries and cause those arteries to go into spasm and shut, robbing even more areas of the brain of oxygen and increasing the amount of damage,” said Dr. Gorelick, who moderated a press briefing on the results of the trial. “Vasospasm is a huge problem and we don't treat it well. This novel approach of putting in a balloon catheter is exciting. It is definitely worth pursuing,” he said.
ARTICLE IN BRIEF
Patients who received prophylactic balloon angioplasty soon after a ruptured brain aneurysm were less likely to have vasospasm or to need an emergency balloon angioplasty later. Additionally, angioplasty improved neurological outcomes in patients who were in better clinical condition.