**Abstract**

Cerebral aneurysms are common cerebrovascular diseases most frequently manifest with vascular rupture and subsequent subarachnoid hemorrhage. Microsurgical clipping is considered the best long-term treatment, despite of the increase of endovascular interventional treatments in the latest years. Vascular control is a pivotal concept for aneurysms surgery, which provides the application of temporary clip in case of rupture, whereas the application of permanent clip requires the perfect knowledge of aneurysm anatomy. Several techniques to obtain the obliteration of the aneurysm while preserving the parent vessels and its branches have been described. Micro-Doppler ultrasonography (MUSG), indocyanine green video angiography (ICG-VA), and electrophysiological neuromonitoring (IONM) are all useful intraoperative tools, which can improve the safety of surgical procedures and achieve the goal of aneurysm obliteration with parent vessel and perforating preservation.

**Keywords:** cerebral aneurysm, clipping techniques, indocyanine, micro-doppler, neuromonitoring

### **1. Introduction**

Cerebral aneurysms are common cerebrovascular diseases with an incidence rate ranging between 2% and 6% [1, 2]. Aneurysm rupture is the most frequent presentation of intracranial aneurysm, causing intracranial hemorrhage, usually subarachnoid hemorrhage (SAH) [3, 4]. The incidence rate of SAH is about 6 to 8 cases per 100,000 in the western population, with about 10,000–20,000 cases per year [3]. SAHassociated mortality is 50% at 30 days, and only up to 30% of patients can return to normal life after SAH [3]. In the latest years, endovascular interventional treatments of intracranial aneurysms have increased rapidly, but microsurgical clipping is still considered the best long-term treatment for this disease [5–10].

Temporary blockage of the feeding artery of the aneurysm, associated with simple or multiple applications of clips along the neck, are techniques that can allow the dissection and remodeling of the neck with obliteration of the aneurysm [11, 12].

However, all these techniques are associated with the risk of parent vessel stenosis and perforating artery damage, leading to brain ischemic damage and neurological defect [1]. The morbidity related to ischemic complications of the surgery of cerebral aneurysms is up to 7.6% [13, 14]. Therefore, the goal of surgical treatment is an optimal obliteration of the aneurysms without residual, while preserving the parent vessels and their branches [5].

Micro-Doppler ultrasonography (MUSG), indocyanine green video angiography (ICG-VA), and electrophysiological neuromonitoring (IONM) are useful intraoperative tools that are used to improve the safety of surgical procedures and achieve the goal of aneurysm obliteration with parent vessel and perforating preservation [1, 5, 11].

The aim of this chapter is to describe the strategies for surgical treatment of cerebral aneurysms and the tools to detect the correct aneurysm obliteration and the patency of the parent vessel and its branches. These techniques allow for improving the safety of surgical procedures, while reducing the risk of aneurysm remnants and avoiding irreversible damage to the brain tissue with consequent neurological derangement.
