内頸動脈「背側型」動脈瘤全国調査結果の解析 : Part 2:出血例における治療を中心に  [in Japanese] The Nationwide Surveillance on the Dorsal Aneurysm of the Internal Carotid Artery : Part 2: Study on the Surgical Treatment in Hemorrhagic Cases  [in Japanese]

Because a preoperative rebleeding is one of the most significant prognostic factors as described in the Part 1 report of the nationwide surveillance on the dorsal aneurysm of the internal carotid artery (ICDA), an early surgery for this hazardous aneurysm is naturally thought to be the first recommended treatment of choice. To clarify the rationality of early surgery for ruptured ICDA, 221 cases that suffered subarachnoid hemorrhage (SAH) out of 365 registered ICDA cases of a nationwide surveillance databank were studied. There were 148 cases that underwent acute surgery (Group A) within 7 days from the onset of SAH, and 57 cases that received delayed operation (Group D) after 8th day. No surgical intervention was done to the remaining 16 cases. Overall surgical outcome of Group A (GR+MD: 60.1%, SD+V: 14.2%, D: 25.7%) was significantly worse (P<0.02) than that of Group D (GR+MD: 79.0%, SD+V: 17.5%, D: 3.5%), despite the fact that the distribution of neurological grades on admission in both Group A (Grade 1+2: 46.8%, Grade 3+4: 44.6%, Grade 5: 8.5%) and Group D (Grade 1+2: 63.6%, Grade 3+4: 29.6%, Grade 5: 6.8%) were not statistically different. Intraoperative bleeding (IOB) was more frequently encountered in Group A (43.2%) than in Group D (14.0%) with a significant difference (P<0.05). Almost half of IOB were the type of a rupture in which the parent arterial wall or neck per se was torn away both in Group A (56.3%) and in Group D (50.0%). But the outcome of those with neck-torn type IOB in Group A was much worse (GR+MD: 36.1%, SD+V: 25.0%, D: 38.9%) than those with that in Group D (GR+MD: 60.0%, SD+V: 40.0%, D: 0%) although no significant difference was present between the 2 groups. In summary, the outcome of surgical treatment for ICDA at acute stage is significantly worse than that at late stage at the moment because of the extremely poor prognosis in cases with neck-torn type IOB during acute surgery. To overcome poor prognosis resulting from rebleeding at acute stage, further investigation with more cases must be conducted to clarify the recommendable early surgical method improve the outcome of acute surgery for ruptured ICDA.