Chapter 155 - Surgical and Endovascular Management of Patients With Unruptured Aneurysm

Abstract

With the advances in imaging techniques, a large number of intracranial aneurysms are being detected before they rupture. The overall prevalence of unruptured intracranial aneurysms (UIAs) is reported to be 3.2%. Most UIAs are located in the anterior circulation. The prevalence of UIAs increases with age, is higher in women than in men, increases with certain disorders, and is higher in patients with a family history of subarachnoid hemorrhage. Small aneurysms are usually asymptomatic and are frequently detected incidentally. UIAs can be identified during evaluation of hemorrhage from another aneurysm or when they present with mass effect, cranial nerve deficits, seizures, or motor and sensory deficits. Imaging techniques include magnetic resonance angiography (MRA), computed tomography angiography (CTA), and digital subtraction angiography (DSA). The overall annual rupture risk rate of UIAs is around 1%. The risk of rupture increases with female gender, old age, family history of aneurysms, personal history of subarachnoid hemorrhage, and a history of hypertension, autosomal dominant polycystic kidney disease (ADPKD), and smoking. Larger aneurysms, aneurysms that enlarge during follow-up, aneurysms that are located in the posterior circulation and posteroanterior communicating artery, multilobulated aneurysms, multiple aneurysms, and symptomatic aneurysms are at increased risk of rupture. Treatment strategies include conservative management, endovascular intervention, or surgical treatment. Endovascular management is associated with a reduction in procedural morbidity, length of hospital stay, and mortality as compared to surgical clipping, but microsurgical treatment has lower recurrence and retreatment rates. New endovascular techniques, including flow diversion, have lower recanalization and retreatment rates than conventional endovascular methods. Follow-up imaging should be performed at regular intervals, especially for conservatively treated aneurysms and incompletely obliterated aneurysms.