Angiographic Morphology of the Posterior Communicating Artery and Basilar Artery in Patients with ICA-PComA Aneurysm Shinji IJICHI, Naomi IJICHI*, Kiyoshige NIINA, Fumishige NAKAMURA, Mitsuhiro OSAME* and Sumitaka TOKITO** Divisions of Internal Medicine and **Neurosurgery, Kagoshima Municipal Hospital, Kagoshima; *The Third Department of Internal Medicine, Faculty of Medicine, Kagoshima University, Kagoshima

Abstract

The relationships between the angiographic morphology of the posterior communicating artery (PComA) and the basilar artery (BA) and saccular aneurysms at the internal carotid artery (ICA) - PComA junction were evaluated in 23 patients with ICA-PComA aneurysm and 46 controls. No significant differences were found in the height of the basilar top, the dislocation and inner diameter of the BA, and the distance between the basilar top and the ICA-PComA junction. However, the angle between the PComA and C2 portion of the ICA was larger and the PComA straighter in ICA - PComA aneurysm patients. Tension in the PComA and mechanical damage to the divergent angle of the PComA are probably important factors in the development of ICA-PComA aneurysms. Key words:

cerebral

aneurysm,

angiography,

Introduction The pathogenesis of saccular aneurysms is presently controversial. Current proposed mechanisms include congenital and acquired factors.") Many studies of the mechanism of aneurysm development have been reported,") but mechanical factors involved in internal carotid artery-posterior communicating artery (ICA-PComA) aneurysms have received little attention. Here, we report the comparative angiographic morphology of the PComA and basilar artery (BA), emphasizing mechanical factors associated with the origin and growth of ICA-PComA aneurysms. Materials

and

Methods

Retrograde brachial angiography was performed on 23 patients with ICA-PComA aneurysms and 46 controls. Controls included 34 cases with ruptured aneurysms other than ICA-PComA (including four Received

October

2, 1989;

Accepted

October

pathogenesis,

ICA-PComA

aneurysm

cases with BA aneurysm), five cerebral hemorrhage with no detectable angiographic abnormality, four arteriovenous malformation, etc. We excluded angiograms in which: 1) both the ICA and BA were not visualized simultaneously by the right retrograde brachial technique; 2) no clear anteroposterior (AP) view of the BA was obtained; 3) the posterior cerebral artery (PCA) originated directly from the ICA and the PCA-BA connection was not clear. Table 1 summarizes the clinical features. Figures 1-3 show measurements of the height of the basilar top, the distance between the basilar top and the ICA-PComA junction, and the maximum dislocation of the BA associated with a curved BA (dislocated BA). Many factors can influence the relative position on an angiogram. Distances were therefore expressed as a percentage of the vertical height from the plane of the orbital floor to the parietal inner table on the lateral view (Figs. 1 and 2), and of the greatest distance between the two inner tables of the temporal bones on the AP view (Fig. 3).

31, 1990

Author's present address: S. Ijichi, M.D., The Third Department of Internal Medicine, Faculty of Medicine, Kagoshima University, Kagoshima, Japan.

Table

Fig. 1

1

Summary

of clinical

features

Fig. 2

A: Right retrograde brachial angiogram, lateral view. B: Schematic diagram of the measure ment of the distance between the basilar top and the ICA-PComA junction [t/a x 100 (%)]. 0 means the angle between PComA and C2 portion of the ICA. C: PComA shape on lateral view. Group I: straight or slightly curved PComA, Group II: slightly sigmoid shape PComA, Group III: markedly curved or sigmoid shape PComA.

Fig. 3

A: Left retrograde

A: Left retrograde brachial angiogram, lateral view. B: Schematic diagram of the measure ment of the basilar top height [h/a x 100 (%)]

The angle between the PComA and C2 portions of the ICA was measured as shown in Fig. 2. The shapes of the PComA on lateral views were classi fied into the following 3 groups to evaluate the ten sion on the BA: Group I, straight or slightly curved; Group II, slightly sigmoid shape; and Group III, markedly curved or sigmoid shape. The positions of the ICA-PComA aneurysm were determined on both AP and lateral views.

Results Table 2 shows the angiographic findings. There were no significant differences in the height of the basilar top, dislocation of the BA, inner diameter of the BA, and distance between the basilar top and the ICA-PComA junction. However, significantly

brachial

angiogram,

antero

posterior view. B: Schematic diagram of the measurement of the basilar artery dislocation [d/b x 100 (%)].

larger angles tion of the

between the PComA ICA were found

and the C2 por in ICA-PComA

Table

2

Angiographic

Table

3

Shape

findings

for BA and PComA

of PComA

aneurysm patients (p < 0.03). Table 3 shows that ICA-PComA aneurysm patients demonstrated straighter PComA than controls (chi-square = 13.8, p

Angiographic morphology of the posterior communicating artery and basilar in patients with ICA-PComA aneurysm.

The relationships between the angiographic morphology of the posterior communicating artery (PComA) and the basilar artery (BA) and saccular aneurysms...
289KB Sizes 0 Downloads 0 Views