Three-Dimensional Angiographic Evaluation of Middle Cerebral Artery Trunk Aneurysms: Demonstration of the Close Relationship Between the Early Frontal Cortical Branches and Lateral Lenticulostriate Arteries

Rescue endovascular treatment for rapid regrowth of aneurysm remnant on middle cerebral artery trunk after unsuccessful surgical clipping in patients with a ruptured cerebral aneurysm: A report of two cases

We report two rare cases treated with coiling after rapid regrowth (within a month) of an aneurysm remnant on the middle cerebral artery (MCA) trunk after incomplete surgical clipping. The first case, a 47-year-old man with subarachonoid hemorrhage (SAH) (Hunt-Hess grade II, Fisher grade III) underwent clipping of a ruptured saccular aneurysm with a wide neck on the right early frontal branch arising from the MCA trunk. Incomplete clipping with a 1 mm sized remnant neck was performed to avoid sacrificing the lenticulostriate artery. In a follow-up cerebral angiogram on postoperative day 30, a rapid regrowth of the aneurysm remnant was observed, and on that day, complete obliteration was obtained by rescue endovascular treatment. The second case, a 48-year-old healthy woman with SAH (Hunt-Hess grade II, Fisher grade III) underwent clipping of an anteroposteriorly projecting bilobulated aneurysm on the left M1. Incomplete clipping with a minimal remnant neck was performed. In follow-up digital subtraction angiogram on postoperative day 30, a rapid regrowth of an aneurysm remnant involving only a part of the initial aneurysm near the neck was observed, and on that day, complete obliteration was obtained by rescue coiling. These patients were both discharged without any neurological deficits.

Visualization of Lenticulostriate Arteries on CT Angiography Using Ultra-High-Resolution CT Compared with Conventional-Detector CT

BACKGROUND AND PURPOSE

The newly developed ultra-high-resolution CT is equipped with a 0.25-mm detector, which has one-half the conventional section thickness, one-half the in-plane detector element width, and one-half the reconstructed pixel width compared with conventional-detector CT. Thus, the ultra-high-resolution CT scanner should provide better image quality for microvasculature than the conventional-detector CT scanners. This study aimed to determine whether ultra-high-resolution CT produces superior-quality images of the lenticulostriate arteries compared with conventional-detector CT.

MATERIALS AND METHODS

From February 2017 to June 2017, thirteen patients with aneurysms (4 men, 9 women; mean age, 61.2 years) who underwent head CTA with both ultra-high-resolution CT and conventional-detector CT were enrolled. Two board-certified radiologists determined the number of all lenticulostriate arteries on the CTA coronal images of the MCA M1 segment reconstructed from 512 matrixes on conventional-detector CT and 1024 matrixes on ultra-high-resolution CT.

RESULTS

There were statistically more lenticulostriate arteries identified on ultra-high-resolution CT (average, 2.85 ± 0.83; 95% CI, 2.509-3.183) than on conventional-detector CT (average, 2.17 ± 0.76; 95% CI, 1.866-2.480) (P = .009) in 16 of the total 26 MCA M1 segments.

CONCLUSIONS

Improvements in lenticulostriate artery visualization were the result of the combined package of the ultra-high-resolution CT scanner plus the ultra-high-resolution scanning protocol, which includes higher radiation doses with lower than the national diagnostic reference levels and stronger adaptive iterative dose-reduction processing. This package for ultra-high-resolution CT is a simple, noninvasive, and easily accessible method to evaluate microvasculature such as the lenticulostriate arteries.

Treatment of Large and Giant Middle Cerebral Artery Aneurysms: Risk Factors for Unfavorable Outcomes

OBJECTIVE

This study aimed to assess the clinical and radiologic outcomes after neurosurgical treatment of large and giant aneurysms of the middle cerebral artery (MCA). In addition, we aimed to identify risk factors for unfavorable outcomes.

METHODS

This retrospective study included 105 patients with 106 large or giant MCA aneurysms treated with neurosurgical methods, including microsurgery and endovascular treatment, over a 15-year period.

RESULTS

The mean aneurysm size was 15.3 ± 7.1 mm. Ten (9.4%) were giant aneurysms. The MCA bifurcation was the most common aneurysm site, followed by the MCA trunk and distal MCA. Aneurysm clipping was the most common treatment method, followed by clipping or trapping with bypass surgery and endovascular treatment. However, acute cerebral infarction was the most common complication (16.0%), poor outcomes (modified Rankin Scale score, 3-6) developed in 12.3% of aneurysms after treatment, and 6.6% of treated aneurysms needed retreatment. Multivariate analysis showed that independent risk factors for acute cerebral infarction after treatment were aneurysms located on the MCA trunk and 2 or more underlying diseases. Initial presentation with subarachnoid hemorrhage and complications during treatment were independent risk factors for poor outcomes. In addition, endosaccular coiling was an independent risk factor for retreatment.

CONCLUSIONS

Neurosurgical management should be considered a priority for large and giant MCA aneurysms because of the high rupture rate and clinical symptoms. However, treatment outcomes remain unsatisfactory. Therefore, tailored management with consideration of risk factors for unfavorable outcomes should be implemented.