Aneurysm observation versus intervention: a literature review

Relationship between cerebral aneurysms and variations in cerebral basal arterial network: a morphometric cross-sectional study in Computed Tomography Angiograms from a neurointerventional unit

OBJECTIVE

Segments of cerebral basal arterial network (CBAN) dampen the peak pressure in blood flowing through these arteries, thus minimising the chances of development of cerebral aneurysms. The objective of this research was to find the relationship of occurrence of intracranial aneurysms to variations of the components of the CBAN.

DESIGN AND SETTING

This is an observational, quantitative and retrospective research, which used cerebral CT angiography (CCTA) images.

PARTICIPANTS

Cerebral CTA of 145 adult patients of both sexes were studied.

MAIN OUTCOME MEASURES

Diameters of segments of CBAN were measured in CCTA images and the relative size of each vessel was calculated to standardise for differences in overall arterial sizes among patients. Relationships among sizes of CBAN components were analysed. Presence of aneurysms in different parts of the CBAN was recorded.

RESULTS

Forty-six aneurysms in right internal carotid artery (ICA) and middle cerebral artery (MCA) and 32 aneurysms in left ICA and MCA segments were noted in 42 and 30 patients, respectively. Aneurysms in anterior communicating artery complex and vertebral-basilar arterial segments were seen in 27 and 8 patients, respectively, while they were not detected in parts of posterior cerebral artery (PCA). The significant (p<0.001) inverse relationships between sizes of posterior communicating artery and the first segment of PCA on both sides indicated that blood inputs to the second part of PCA were similar. Difference in means of the index of arterial size variation for people with aneurysms (mean 0.96, SD 0.23) and without aneurysms (mean 0.86, SD 0.22) was significant (p=0.015).

CONCLUSION

Variation in segments of CBAN was quantified. The peak pressure dampening mechanism in such arterial segments reduces the chances of development of aneurysms.

Treatment of Intracranial Aneurysms

The management of intracranial aneurysms (IAs) remarkably improved due to the development of diagnostic and surgical procedures. Subarachnoid hemorrhage (SAH) from IA rupture constitutes a devastating event, whose prognosis remains unsatisfactory. At present, several researchs are targeted to individuate subjects harboring unruptured IAs and those presenting a higher risk for rupture. Numerous risk factors for the rupture of lAs have been individuated. The prevalence of intracranial saccular aneurysms in the general population is estimated from 0.2% to 6.8%, with an incidence of SAH at 10/100,000/year. The most relevant morbidity and mortality rates after SAH are related to rebleeding and vasospasm. The primary therapeutic target consists in prevention of rebleeding. At present, therapeutic opportunities for intracranial aneurysms are microsurgery and endovascular treatment.

Computed tomographic angiography for the evaluation of aneurysmal subarachnoid hemorrhage

OBJECTIVES

Computed tomography (CT) followed by lumbar puncture (LP) is currently the criterion standard for diagnosing subarachnoid hemorrhage (SAH) in the emergency department (ED); however, this is based on studies involving a limited number of patients. The authors sought to assess the ability of CT angiography (CTA), a new diagnostic modality, in conjunction with CT/LP to detect SAH.

METHODS

Consecutive patients presenting to the ED with symptoms concerning for SAH were approached. All patients had an intravenous catheter placed and underwent a noncontrast head CT followed by CTA. Patients whose CT did not reveal evidence of SAH or other pathology underwent LP in the ED. CTAs were read within 24 hours by a neuroradiologist blinded to the patient's history.

RESULTS

A total of 131 patients were approached, 116 were enrolled, and 106 completed the study. In six of 116 patients (5.1%), aneurysm was found on CTA with normal CT and positive findings on LP; three had a positive CTA with normal CT and LP findings (one of which had a negative cerebral angiogram), and there was one false-positive CTA. Follow-up of all 131 patients showed no previously undiagnosed intracranial pathology. In this patient population, 4.3% (5/116) were ultimately found to have an SAH and/or aneurysm.

CONCLUSIONS

In this pilot study, CTA was found to be useful in the detection of cerebral aneurysms and may be useful in the diagnosis of aneurysmal SAH. A larger multicenter study would be useful to confirm these results.