News from San Francisco, CA — A new study shows that for most patients with aneurysmal subarachnoid hemorrhage, transcranial microsurgical clamping of a ruptured aneurysm does not prevent more disability than endovascular spring-ring interventional embolization. However, aneurysm clamping better eliminates aneurysms and requires less re-treatment, the investigators said. The article was presented as an abstract at the 82nd annual meeting of the American Association of Neurological Surgeons (AANS) on April 9, 2014. ”We can come to a strong proposition that anterior circulation aneurysms should be surgically clamped,” said the paper’s first author, Robert Spetzler, MD, director of the Belo Neurological Center in Phoenix, AZ. “Picking which patients to adopt which treatment remains an art and is unfortunately not based on science.” At the 82nd annual meeting of the American Association of Neurological Surgeons (AANS), Dr. Spetzler presented the results of six years of the Belo Ruptured Aneurysm Study (BRAT). Head-to-Head Study Based on previous studies reporting similar results for the 2 treatment options, Dr. Spetzler and his colleagues set out to compare the 2 treatment options, following the principles of a head-to-head study. They randomly assigned 238 patients with ruptured aneurysms to the clamping group and 232 to the spring-ring embolization group. Six years later, 336 patients who had been treated were available for further analysis and evaluation. Thirty-eight percent of patients assigned to the spring-ring embolization group crossed over into the clamping group, while 2% of patients in the clamping group crossed over into the spring-ring embolization group. At the end of the first year, 24% of patients assigned to the spring-ring embolization group had a modified Rankin Scale (mRS) score greater than 2, indicating mild to severe disability. In contrast, 35% of patients assigned to the clamping group had a modified Rankin Scale score that high. The difference between the two groups was statistically significant (P = .03). But by the third year, the difference between the two groups had disappeared, according to a 2013 study published in the Journal of Neurosurgery. Also, although there was an absolute difference of 5.8% between the spring-ring embolization group versus the clamping group, the difference between the two groups was not significant. In the sixth year, which is the most recent study, the results are reported here. Modified Rankin Scale scores greater than 2 resulted in 35% of patients assigned to the clamped group and 41% of patients assigned to the spring-ring embolization group, with no statistically significant difference between the two groups (P = .24). We have to remember that treatment of patients with intracranial aneurysms must last a lifetime, not just a few years,” Dr. Spetzler said. At each time period, spring-ring embolization still resulted in better modified Rankin Scale scores for posterior circulation aneurysms, but for anterior circulation aneurysms at each time period, the modified Rankin Scale scores were equal. Dr. Spetzler noted that just three posterior inferior cerebellar aneurysms ended up in the spring-ring embolization group, while 13 were in the clamping group. Because these aneurysms had a worse overall prognosis, superior modified Rankin Scale scores were obtained at 1 year with spring-ring embolization. Also at year 6, 96% of patients in the clamped group had complete resolution of their aneurysms, compared with only 48% of patients in the spring-ring embolization group, a finding that was also statistically significant (P = .0001). Also, only 4% of patients in the clamping group required retreatment, compared with 13% of patients in the spring-ring embolization group, a statistically significant difference between the two groups (P =.001). Most aneurysms “are a really great study,” said Robert Rosenwasser, chairman of neurosurgery at Thomas Jefferson University in Philadelphia, Pennsylvania, USA, in an official commentary done in response to the study. And the official comments in response to the study were part of the AANS meeting. “Most of the data on aneurysms, particularly anterior circulation aneurysms, support transcranial surgery,” he said. But he pointed out to surgeons at his institution that slightly better outcomes have been obtained in certain categories of patients in the spring-ring embolization group than in the clamping group, particularly those with posterior circulation aneurysms, those with poor grade aneurysms and those with comorbid major medical disease.” I think every institution needs to look at its own morbidity and mortality. Not everybody can go to the city of Phoenix, not everybody has the level of skill that the Belo Group has. And I also think there may be instances in your own unit where taking endovascular therapy may have better outcomes.”