抄録
The essentials for safe, reliable and prompt ruptured anterior communicating aneurysm surgery through the pterional approach were retrospectively studied by the analysis of preoperative cerebral angiogram (AG) and operative procedure, including topographical microanatomy.
The subjects of the study were 28 patients who had undergone acute neck clipping of aneurysms performed by the same surgeon over the last three years.
As for preoperative AG, left A1 dominancy was observed in 12 cases (43%), right A1 dominancy in 7 cases (25%) and no dominancy in 9 cases (32%). The number of cases classified according to the projection of the aneurysm were 19 (68%) for anterior, 7 (25%) for inferior and 2 (7%) for dorsalposterior.
The size of the aneurysm was 4~14mm (mean 7mm), though the height was 2~14mm (mean 7mm). Concerning the antero-posterior relationship of bilateral A2, segment, there were nine cases (32%) of right A2 posterior to left and 11 cases (39%) of left A2 posterior to right. In eight cases (29%) there was no difference.
As regards the essentials of the operative procedure, 15 patients (54%) underwent right craniotomy, while 13 patients (46%) underwent left craniotomy. The area of the craniotomy was extended further to the anterior and the midline in left craniotomy than in right.
Premature rupture happened in 2 cases (7%) with inferior projection. A temporary clip on the dominant A1 was applied in 7 cases (25%), two of which were cases of premature rupture and five of which were cases of intentional clipping on dissection of the aneurysmal complex. The mean occlusion time was 9 min.. Rectal gyrus was partially removed in only 2 cases (7%).
From these observations, the following conclusions were made. The dominant side of the A1 segment was basically used as the side for the craniotomy. When no dominancy was seen, the posterior side of the A2 segment was chosen.
The further extended craniotomy on the left side should be used by right handed surgeons. The advantage of the approach through the same side as the dominant A1 segment was that surgical procedure was extremely safe because of premature rupture and dissection of the aneurysmal complex. On the other hand, it is a disadvantage when the A2 segment is situated anteriory to the oposite side. In these cases, oposite A1 and A2 could be dissected through the“dorsal A1-A2 junction related trangle”. Furthermore, the use of the fenestrated clip was effective.
