Surgical Treatment of Unruptured Intracranial Aneurysms

V.S. Kolotvinov, V.P. Sakovich, M.B. Gerasimov, E.R. Lebedeva

Uralsky Interregional Neurosurgical Center named after Prof. Shefer, Ekaterinburg, Russia


Cerebrovascular diseases are the third cause of deaths in industrial countries. Subarachnoid hemorrhages (SAH) account for one forth of their total number. The rate of SAH varies from 6 up to 19.4 cases per 100 000 men/year. A rupture of intracranial aneurysms is a cause of non-traumatic SAH in 80-90% of cases. As a rule, aneurysmal SAH is watched in people, capable of working (40-50 years old). Despite achievements of surgical and conservative treatment, 50% of patients die of primary hemorrhage or early complications. All the above-mentioned conditions considerable economic and social significance of this disease.

Surgical treatment of intracranial aneurysms at different periods of intracranial hemorrhage is connected with a rather high risk of development of intraoperative and postoperative complications. Surgery of unruptured aneurysms is characterized by a lower risk of complications development and a smaller rate of postoperative mortality. However, a group of unruptured aneurysms is not homogenous and can be divided into three subgroups. The first subgroup includes aneurysms, characterized by the following symptoms:
- a pseudotumorous course with dominating focal and/or general cerebral symptoms, connected with a mass cerebral lesion;
- an ischemic course, when there are manifestations of ischemic disorders of cerebral circulation, connected with embolization of distal branches of a vessel, carrying aneurysm, or with its stenosing by an aneurysm body.

The second group is represented by asymptomatic aneurysms. These are either aneurysms, diagnosed simultaneously with aneurysms, being a cause of intracranial hemorrhage or other symptoms in multiple aneurysmal pathology, or aneurysms, revealed in patients with a high risk of their development. The third group comprises intracranial aneurysms, which are accidental diagnostic findings in patients, examined for other cerebral diseases.

We diagnosed 82 unruptured aneurysms in 69 cases, treated in our clinic in 1995-2003. Aneurysms, which manifested themselves in different neurologic symptoms, were diagnosed in 31 cases; asymptomatic aneurysms were revealed in 37 patients (33 aneurysms them were present against a background of multiple pathology and 4 patients had them in their family history). Aneurysms were diagnostic findings in 8 cases.

Surgical treatment was carried out in 63 patients. There were 25 operations for aneurysms with different versions of clinical manifestations. Refusal of surgical treatment in 6 cases was caused by a giant size of aneurysm, anatomic peculiarities of the Willis circle and impossibility of both clipping and trapping of a carrying artery, complete thrombosis and calcification of giant aneurysms. Necks of 19 aneurysms were clipped; trapping of a carrying artery was performed in 6 cases; it was accompanied by creation of extra-intracranial (2 cases) and two intra-intracranial anastomoses (1 case).

As for asymptomatic aneurysms, there were 38 interventions, performed in 33 patients with multiple aneurysms. Their total number was 73; 25 out of 40 asymptomatic aneurysms were clipped; 15 aneurysms were coated by a free muscle graft because of their small size. Operations for single aneurysms, revealed in screening of family history, were performed in 4 cases. They consisted in clipping of aneurysm's neck. All the patients were operated with using a pterional "key-hole" approach.

There were 8 cases with single aneurysms, diagnosed accidentally; one of them gave no consent to the operation. Necks of 7 aneurysms were clipped with using a pterional "key-hole" approach.

Results of surgical treatment were estimated on the basis of Glasgow Outcome Scale. Excellent or good clinical results were watched in 97.1% of cases. A satisfactory result with development of persistent neurologic deficit was observed in 2 cases (2.9%) with giant aneurysms and preoperative clinical manifestations.