Neurointervention.  2015 Sep;10(2):82-88. 10.5469/neuroint.2015.10.2.82.

Enlarged Parent Artery Lumen at Aneurysmal-Neck Segment in Wide-Necked Distal Internal Carotid Artery Aneurysms

• Lee JW
• Woo JM
• Lim OK
• Jo YE
• Kim JK
• Kim ES
• Lee DH

• KMID: 2148998
• DOI: http://doi.org/10.5469/neuroint.2015.10.2.82

Abstract

PURPOSE
Hypothesizing that the parent artery (PA) diameter of the aneurysm-neck segment is larger than those of normal segments, especially in wide-necked aneurysm cases, we conducted 3D angiographic analyses in wide-necked aneurysm cases focusing on the luminal morphologic change of the PA.
MATERIALS AND METHODS
Under the approval of local IRB, we enrolled 26 patients with distal internal carotid artery (ICA) aneurysms, which were treated with stent assisted coiling. The PA diameters along the centerline were measured at 6 points with built-in software by two observers. Those 6 points were P1 and P2 proximally, P3 and P4 at the aneurysm ostium margins, and P5 and P6 distally. We performed an ANOVA test and a Bonferroni method for post hoc analyses. Linear regression analysis was performed to find any morphologic influencing factors.
RESULTS
There were 20 distal ICA aneurysms out of 26 consecutive cases after exclusion. The differences in diameter at each point were statistically significant (p<0.0001). On post hoc analyses, the difference between P4 and P5 was significant both in maximum and mean PA diameters (p<0.0001 and p<0.001, respectively). Multivariate analyses failed to reveal any morphological influencing factor.
CONCLUSION
PAs harboring a wide-necked aneurysm requiring stent assistance for coiling showed significant enlargement of the lumen, especially at the distal transition segment of the aneurysm ostium and the PA.

Keyword

Cerebral aneurysms; Parent artery; Cerebral angiography; Intracranial stenting; Vascular morphology

MeSH Terms

Aneurysm*
Arteries*
Carotid Artery, Internal*
Cerebral Angiography
Ethics Committees, Research
Humans
Intracranial Aneurysm
Linear Models
Multivariate Analysis
Parents*
Phenobarbital
Stents
Phenobarbital

Figure

• 

  Fig. 1 Angiography was performed in a patient with an incidental aneurysm. (A) Volume rendering (VR) image of the 3D angiography showing a lobulated, wide-necked aneurysm at the ophthalmic segment of the right internal carotid artery. (B) A drawing in transparent view demonstrates the ostium of the wide-necked aneurysm and associated segmental distention of the parent artery lumen as well. (C) A self-expanding stent is placed across the neck of the aneurysm. We exaggerated the malapposition problem in this particular picture. We may improve the apposition by choosing a larger-diameter stent to fit into the enlarged segment. (D) However, due to the size limitation in the diameter and intrinsic tortuosity of the parent artery, there could be significant malapposition, even with significant oversizing of the stent.

• 

  Fig. 2 Angiography was performed in a patient with an incidental aneurysm. (A) Volume rendering image of the 3D angiography showing a small but wide-necked right paraophthalmic ICA aneurysm. The parent artery diameter decreases gradually from the proximal to the distal segments. (B) After segmentation of the aneurysm sac from the parent artery lumen, the centerline (pink line) appears automatically following indication of the beginning and finishing points on the workstation. We can trace the parent artery lumen along the centerline (pink line) and obtain the mean and maximum diameter of the parent artery lumen at each point (P1-P6). We designated six points as described in the method section. (C) The software automatically generates the summary of the measurement, including the aneurysm and parent artery.

• 

  Fig. 3 Bar-and-whisker graphs of maximum (A) and mean diameters of the parent artery (B) from the most proximal point (P1) to the most distal point (P6) of the parent artery segment. Significant diameter changes are noted between P4 and P5 in both graphs.

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