Endovascular coiling in 131 patients with low complication rate justifies treating most unruptured intracranial aneurysms.

Background: The management of unruptured intracranial aneurysms (UIAs) remains controversial. The International Study of UIAs (ISUIA) found low rates of rupture and appreciable treatment risks. This finding could be interpreted as suggesting that many UIAs should not be treated. Coiling technology has continuously improved over the years and, since the publication of the International Subarachnoid Aneurysm Trial results, increasing numbers of aneurysms have been coiled, and neurointerventional skills have significantly improved. We present the results of endovascular coiling of 131 patients with UIAs from a high volume unit and a risk-benefit analysis based on patient and aneurysm characteristics.

Patients and methods: From December 1996 to September 2005, 131 patients (93 women and 38 men, mean age 51 years) with 151 UIAs were treated using detachable coil embolisation. Data on procedural complications, patient and aneurysm characteristics, clinical and radiological follow up were entered into a prospectively collected database. A risk-benefit analysis was performed.

Findings: Endovascular treatment was successful in 145 (96 %) aneurysms. One aneurysm ruptured intraoperatively with a fatal outcome. Ten thromboembolic events occurred, leaving one patient moderately disabled. The combined morbidity and mortality rate per patient at 6 months is 1.5 % (95 % confidence interval: 0.07 - 5.7 %). A risk-benefit analysis comparing these data with the published natural history suggests that treatment with low complication rates can be offered to most patients with UIAs.

Conclusion: UIAs can be coiled with low morbidity and mortality. The risk-benefit analysis suggests that it is reasonable to off er treatment to patients with the exception of patients over 60 years of age with incidentally found aneurysms less than 7 mm in diameter of the anterior circulation.