Blood Blister-Like Aneurysms of the Internal Carotid Artery.

Internal carotid artery blood blister-like aneurysms are challenging lesions that arise from the artery trunk at non-branching sites. They have been recognized since 1969 and are distinct from typical saccular aneurysms. Usually, these aneurysms are broad-based, with no clearly identifiable neck and have extremely friable and fragile walls, thus with a great propensity to cause subarachnoid hemorrhage and to rupture during treatment. Apparently, blister-like aneurysms are formed through an acquired defect of the inner layers (tunica intima and media) of the internal carotid artery wall, probably due to hemodynamic stress in the carotid siphon.Several surgical and endovascular techniques have been described for the treatment of these aneurysms, however, there is still no consensus on the best technique or method, exposing how challenging the treatment of internal carotid artery blister-like aneurysms is, for both neurosurgeons and neurointerventionists. In this chapter, we review the main aspects of the pathogenesis, diagnosis, and therapeutics and report our experience in the microsurgical treatment of these formidable lesions.

Initial experience in the microsurgical treatment of ruptured brain aneurysms in the endovascular era: characteristics and safety of the learning curve in the first 300 consecutively treated patients.

PURPOSE: Currently, there is an increasing tendency to refer only complex aneurysms for microsurgery. The formation of new neurosurgeons dedicated to open vascular neurosurgery becomes challenging in a situation in which complex aneurysms must be dealt with early in the career, raising questions about the safety of the learning curve. METHODS: We analyzed the characteristics and surgical results of the first 300 consecutively treated patients after subarachnoid hemorrhage by a single neurosurgeon. The incidence of surgical complications and clinical outcomes during the learning curve were analyzed, looking for critical periods regarding patient safety. Microsurgical operative times were also studied. RESULTS: A high frequency of wide-necked aneurysms was observed (70.3%), and, as a result, large (> 10 mm), MCA and paraclinoid aneurysms were overrepresented. A statistically significant correlation between surgical experience and clinical outcomes was observed, with progressive surgical experience resulting in a lower incidence of unfavorable outcomes. We also observed a higher frequency of major surgical complications, unfavorable clinical outcomes, and lower complete occlusion rates among the first 40 patients. Microsurgical operative times progressively and significantly decreased during the learning curve. CONCLUSIONS: We observed a high prevalence of wide-necked aneurysms. Young neurosurgeons must be trained and prepared to deal with these aneurysms early in their careers. Although we observed a decrease in unfavorable results with cumulative surgical experience, the first 40 cases were associated with higher rates of major surgical complications, worse clinical outcomes, and lower complete occlusion rates, indicating that this period may be more critical to patient safety.

Subarachnoid neurocysticercosis and an intracranial infectious aneurysm: case report.

Infectious intracranial aneurysms (IIAs) represent 2%-6% of all intracranial aneurysms and, classically, have been associated with bacterial or fungal agents. The authors report the case of a 42-year-old woman who presented with a typical history of subarachnoid hemorrhage. Digital subtraction angiography (DSA) showed an aneurysmal dilatation on the frontal M2 segment of the left middle cerebral artery (MCA). The patient was treated surgically, and multiple cysts were found in the left carotid and sylvian cisterns, associated with a dense inflammatory exudate that involved the MCA. The cysts were removed, and a fusiform aneurysmal dilatation was identified. The lesion was not amenable to direct clipping, so the authors wrapped it. Histopathological analysis of the removed cysts revealed the typical pattern of subarachnoid neurocysticercosis. The patient received cysticidal therapy with albendazole and corticosteroids, and she recovered uneventfully. Follow-up DSA performed 6 months after surgery showed complete resolution of the aneurysm. The authors performed a review of the literature and believe that there is sufficient evidence to affirm that the subarachnoid form of neurocysticercosis may lead to the development of an IIA and that Taenia solium should be listed among the possible etiological agents of IIAs, along with bacterial and fungal agents.