Okuyama Tohru, Sasamori Yumiko, Takahashi Hachisaburou, Fukuyama Kouichi, Saito Koji
Department of Neurosurgery, Takahashi Neurosurgical Hospital, 20-1-30 Nishimachi-minami, Nishiku, Sapporo 063-0062, Japan.
No Shinkei Geka. 2004 Feb;32(2):121-5.
The purpose of this investigation was to study the incidence rate of rupture with respect to the site and size of multiple cerebral aneurysms that include both ruptured and unruptured aneurysms. Site and size were investigated in 58 cases of this type of multiple cerebral aneurysm. All cerebral aneurysms were examined with MR angiography, 3D-CT angiography and digital subtraction angiography, as well as seeing measured using 3D-CT or digital subtraction angiography. As regards the site of the 58 ruptured cerebral aneurysms under study, 18 were internal carotid aneurysms (C2 or C3: 4 cases, IC-PC: 12 cases, IC-ancho.: 1 case, IC terminal: 1 case), 25 were anterior communicating aneurysms, 10 were middle cerebral aneurysms, 4 were anterior cerebral aneurysms and 1 case was a VA-PICA aneurysm. The ruptured internal carotid aneurysms were 4.0-21.0 mm in size, the anterior communicating aneurysms were 1.8-13 mm, the middle cerebral aneurysms were 2.0-21.3 mm, the anterior cerebral aneurysms were 3.2-9.1 mm, and the VA-PICA aneurysm was 4.4 mm. The sites of the 89 unruptured cerebral aneurysms break down as follows: 29 were internal carotid aneurysms (C2 or C3: 4 cases, IC-PC: 10 cases, IC-ancho.: 10 cases, IC terminal: 5 cases), 18 were anterior communicating aneurysms, 34 were middle cerebral aneurysms, and there were 5 cases of posterior circulation aneurysm. In size, the unruptured internal carotid aneurysms were 1.0-18.3 mm, the anterior communicating aneurysms were 1.0-6.5 mm, the middle cerebral aneurysms were 1.0-10.3 mm, the anterior cerebral aneurysms were 1.0-3.3 mm, and the posterior circulation aneurysms were 2.2-17.3 mm. Out of 58 ruptured cerebral aneurysms, 44 were of the largest size category, and 53 (91.4%) were in the largest size category and/or anterior communicating aneurysms. The accumulated incidence rate of rupture of anterior communicating aneurysms rose suddenly upon reaching 2 mm in size, and after reaching 3 mm, these aneurysms accounted for a nearly uniform 55%-60% of the incidence rate of rupture. The accumulated incidence rate of rupture of IC-PC aneurysms rose drastically at 4 mm in size with the data describing a parabolic slope when graphed. IC-PC aneurysms represented a uniform 55% of the incidence rate of rupture after reaching 8 mm in size. The accumulated incidence rate of rupture of middle cerebral aneurysms rose in a gently sloping parabola beginning at 4 mm, and stabilized at 20% upon reaching 10 mm. These results suggest that each site is associated with a characteristic size and rate of aneurismal rupture. Special attention should thus be paid to large and anterior communicating aneurysms when operating on multiple cerebral aneurysms.
本研究的目的是探讨包括破裂和未破裂动脉瘤在内的多发性脑动脉瘤的破裂发生率与部位及大小的关系。对58例此类多发性脑动脉瘤患者的部位和大小进行了研究。所有脑动脉瘤均通过磁共振血管造影（MR angiography）、三维CT血管造影（3D - CT angiography）和数字减影血管造影（digital subtraction angiography）进行检查，并使用三维CT或数字减影血管造影进行测量。在所研究的58例破裂脑动脉瘤中，18例为颈内动脉瘤（C2或C3段：4例，颈内 - 后交通段：12例，颈内 - 海绵窦段：1例，颈内动脉终末段：1例），25例为前交通动脉瘤，10例为大脑中动脉瘤，4例为大脑前动脉瘤，1例为椎动脉 - 小脑后下动脉瘤。破裂的颈内动脉瘤大小为4.0 - 21.0mm，前交通动脉瘤为1.8 - 13mm，大脑中动脉瘤为2.0 - 21.3mm，大脑前动脉瘤为3.2 - 9.1mm，椎动脉 - 小脑后下动脉瘤为4.4mm。89例未破裂脑动脉瘤的部位分布如下：29例为颈内动脉瘤（C2或C3段：4例，颈内 - 后交通段：10例，颈内 - 海绵窦段：10例，颈内动脉终末段：5例），18例为前交通动脉瘤，34例为大脑中动脉瘤，5例为后循环动脉瘤。在大小方面，未破裂的颈内动脉瘤为1.0 - 18.3mm，前交通动脉瘤为1.0 - 6.5mm，大脑中动脉瘤为1.0 - 10.3mm，大脑前动脉瘤为1.0 - 3.3mm，后循环动脉瘤为2.2 - 17.3mm。在58例破裂脑动脉瘤中，44例属于最大尺寸类别，53例（91.4%）属于最大尺寸类别和/或前交通动脉瘤。前交通动脉瘤大小达到2mm时，破裂累积发生率突然上升，达到3mm后，这些动脉瘤在破裂发生率中占比几乎一致地为55% - 60%。颈内 - 后交通动脉瘤大小达到4mm时，破裂累积发生率急剧上升，绘制数据时呈抛物线斜率。颈内 - 后交通动脉瘤大小达到8mm后，在破裂发生率中占比一致为55%。大脑中动脉瘤破裂累积发生率从4mm开始呈平缓抛物线上升，达到10mm时稳定在20%。这些结果表明，每个部位都与动脉瘤破裂的特征性大小和发生率相关。因此，在对多发性脑动脉瘤进行手术时，应特别关注大型和前交通动脉瘤。
