NEW YORK (Reuters Health) – Endovascular treatment of intracranial aneurysms 3 mm or smaller in diameter is difficult and risky — but it’s successful in over 90% of patients, according to pooled data from seven studies.

“Endovascular treatment of very small intracranial aneurysms continues to be challenging from a technical point of view,” investigator Dr. Giuseppe Lanzino told Reuters Health by email.

He added, “Our review of the literature has shown that endovascular treatment of very small aneurysms although safe and effective in the vast majority of patients carries a risk of thromboembolic and hemorrhagic complications which is not negligible.”

In the January issue of Stroke, Dr. Lanzino and his colleagues at the Mayo Clinic in Rochester Minnesota, report on their meta-analysis of studies involving 442 patients with intracranial aneurysms with a maximum dimension of 3 mm. Roughly 61% of the aneurysms were ruptured at presentation.

Overall, 91.6% of small aneurysms were completely occluded at immediate postoperative angiographic follow-up. Occlusion failed in 5.4%. Occlusion rates were similar in ruptured and non-ruptured aneurysms.

The procedural rupture rate was 8.3%. Mortality due to procedural rupture was 2.4%. The overall rate of post-procedural hemorrhage was 1.6%, and all of these patients died.

Despite the overall high success rate, the researchers point out that the risks are greater with these very small aneurysms than with larger ones.

“Therapeutic decisions in these patients must be individualized,” Dr. Lanzino emphasized. “It is possible that with increasing operator experience and improvement of devices available, embolization of very small aneurysms will be done in the future with results not dissimilar to embolization for larger aneurysms.”

Reference:

Stroke 2010;41:116-121.