Aneurysms of the pericallosal artery (literature review)

Abstract

The study objective is to analyze scientific sources describing features of surgical treatment of aneurysms of the pericallosal artery (APcA) and unfavorable outcome risk factors.Materials and methods. The analysis included 4 russian and 57 foreign sources.Results and conclusion. Conservative treatment of patients with ruptured APcAs yields unsatisfactory results due to high mortality. Data on surgical outcomes of ruptured APcAs are contradictory: per some sources, they do not differ from results of treatment of cerebral aneurysms of other locations; another sources state that they are worse. The main risk factors are severity per the Hunt–Hess scale ≥IV, large size of intracranial hematoma. Outcomes of surgical treatment of unruptured aneurysms are mostly favorable. Microsurgical clipping allows to achieve favorable results both for ruptured and unruptured APcAs. Due to deep APcA localization, the majority of revascularization surgeries can be performed only using intracranial-to-intracranial bypass. Extracranial-intracranial bypass in the anterior cerebral artery system is rarely performed. For surgical treatment, choice of its timeframe in critically ill patients (grade IV–V by the Hunt–Hess scale) causes difficulties: early surgery prevents repeated hemorrhages, while postponed surgeries eliminate the possibility of affecting this and other factors. There are arguments for preventive exclusion of APcA from blood flow even if its size is <5 mm because of high frequency of APcA ruptures and more severe consequences. For combination of an unruptured APcA with a ruptured aneurysm in another location, either simultaneous exclusion of all aneurysms is performed or two-stage surgery with primary exclusion of the ruptured aneurysm, but the first approach is not always possible. Selection of optimal approach depends on the location of the aneurysm: pterional approach is used for clipping infracallosal aneurysms, variations of interhemispheric accesses – for exclusion of supracallosal aneurysms and aneurysms located at the genu of corpus collosum. Temporary pharmacological cardioplegia is considered a promising method which potentially can replace temporary APcA clipping.