Risk Factors for Formation of Multiple Intracranial Aneurysms

OBJECTIVE: We report the correlation between known risk factors for cerebrovascular disease and formation of multiple intracranial aneurysms. METHODS: We reviewed the medical records and outcomes of 524 patients who had undergone aneurysmal operation at our hospital between January 1996 and May 2001. Of 524 patients who had undergone operations with intracranial aneurysm, 130 patients had multiple intracranial aneurysms. The authors examined the correlations between the risk factors(patient age, sex, menopausal state of female patients, hypertension, cigarette smoking) and the presence of multiple intracranial aneurysms by using chi-square test retrospectively. RESULTS: The male to female ratio was about 1 : 2.05(male : female=129 : 265) for patients with single intracranial aneurysm, and male to female was about 1 : 3.06(male : female=32 : 98) for patients with multiple intracranial aneurysms. Among 256 female patients with single intracranial aneurysm, 182 patients(68.9%) were postmenopausal, and, among 98 female patients with multiple intracranial aneurysms, 81 patients(82.6%) were postmenopausal. The mean age of the patients with single intracranial aneurysm was 54 years, and, with multiple intracranial aneurysms, the mean age was 57.8 years. The presence of hypertension was found in 149 patients(37.8%) with single intracranial aneurysm, and, in 55 patinets (42.3%) with multiple intracranial aneurysms. Cigarette smoking was found in 116 patients(29.4%) with single intracranial aneurysm and 47 patients(36.1%) with multiple intracranial aneurysms. CONCLUSION: There is a significant correlation between menopausal state of female patients and presence of multiple intracranial aneurysms. However, gender, hypertension and smoking are not related to multiple intracranial aneurysms.

Clinical Analysis of Multiple Intracranial Aneurysm

A retrospective review was performed of all patients with multiple intracranial aneurysms treated over a 6-year period. Fifty-three patients with a total of 121 aneurysms were included. Of all patients with aneurysms treated in same interval, the incidence of multiple aneurysms was 11.7%. Multiple aneurysms were much more common in women, with a male to female ratio of 1:3.1. The common locations for multiple aneurysms were posterior communicating artery(28.9%), middle cerebral artery(27.3%) and anterior communicating artery(14.0%). However, location with the highest probability of rupture was the anterior communicating artery(64.7%). In identifying the site of rupture, the presence of focal hematoma on brain CT scan, focal vasospasm, irregularity and size of aneurysmal sacs on angiograms were helpful. Direct operations were performed on all cases. Both the ruptured and unruptured aneurysms were treated in 42(79%) 3 cases, and the ruptured aneurysms only in 11(21%). Among 42 cases, treated for both ruptured and unruptured aneurysms, one-stage operations were performed in 28 cases, whereas two-stage operations were performed in 14 cases. Surgical outcome was favorable in 87% of the cases and mortality rate was 7.5%. The outcome was influenced by preoperative clinical status of the patients, but not by the locations of aneurysms or operative methods.

Clinical Analysis of Multiple Intracranial Aneurysms

In this retrospective clinical analysis for 143 patients who underwent operation due to multiple intracranial aneurysms during the last 12 years(1983-1994), we intended to find out the clinical characteristics, the significant signs for the differentiation between ruptured and unruptured aneurysm, and to compare the results of one-stage operations with those of two-stage operations. The results were s follows; Of 864 patients operated on due to intracranial aneurysms, 143 patients(16.6%) had two or more intracranial aneurysms. Multiple aneurysms were more common in females, with a female to male ratio of 2.4 : 1 as compared with 1.3 to 1 for patients with single aneurysm. Common locations of the aneurysms were the middle cerebral artery, and posterior communication artery, anterior communicating artery, and the anterior choroidal artery, in that order. In identifying the site of rupture, the focal hematoma in brain CT scan, segmental vasospasm, irregularity and sizes of aneurysmal sacs on angiograms were helpful. Aneurysms 3mm or less were less prone to rupture. However, for those with a diameter of more than 4mm, the frequency of rupture increased with the size of aneurysm. Eighty eight percent of patients who underwent operations had a favorable outcome and the operation mortality rate was 7.7%. In patients of Grade I and II, surgical results of the one-stage operation group and two-stage operation group did not differ. In Grade III patients, the results were better for the two-stage operation group, without statistical significance. From our studies we have come to the conclusion that incidental aneurysms found in patients with low risk should be treated at the same time when ruptured aneurysms are clipped.

Clinical Analysis of Multiple Intracranial Aneurysms

Author reviewed the 31 cases of multiple intracranial aneurysms clinically from January 1981 to July 1987, at Inje College Busan Paik Hospital. The results obtained were as follows: 1) The incidence of multiple intracranial aneurysm was 7.8%. In most cases(94%), the number of aneurysm was two. 2) Approximately over 70% of patients were 6th and 7th decades, male to female ratio was 1:3.4. 3) The location of multiple intracranial aneurysms was in order, on the opposite side(39%), on the same side(26%), one in the midline and one on the side(29%). The location of indivisual aneurysms was in order, P-com. A(36%), MCA(25%), A-com. A(17%), ICA(13%). 4) The site of the ruptured aneurysm was determined by CT finding(55%), focal mass effect and spasm in angiography(29%), and others. The accurary was 97%. The possibility of rupture at each location was A-com. A(73%), P-com. A(57%), ICA(38%), MCA(31%). 5) 12 cases among them were treated with one-stage operation and 9 cases with two-stage operation. The post-operative favorable outcome was estimated in 13 cases(54%), the surgical mortality was 13%. There was no statistical difference between two groups.

Clinical Analysis of Multiple Intracranial Aneurysms

Author reviewed the 31 cases of multiple intracranial aneurysms clinically from January 1981 to July 1987, at Inje College Busan Paik Hospital. The results obtained were as follows: 1) The incidence of multiple intracranial aneurysm was 7.8%. In most cases(94%), the number of aneurysm was two. 2) Approximately over 70% of patients were 6th and 7th decades, male to female ratio was 1:3.4. 3) The location of multiple intracranial aneurysms was in order, on the opposite side(39%), on the same side(26%), one in the midline and one on the side(29%). The location of indivisual aneurysms was in order, P-com. A(36%), MCA(25%), A-com. A(17%), ICA(13%). 4) The site of the ruptured aneurysm was determined by CT finding(55%), focal mass effect and spasm in angiography(29%), and others. The accurary was 97%. The possibility of rupture at each location was A-com. A(73%), P-com. A(57%), ICA(38%), MCA(31%). 5) 12 cases among them were treated with one-stage operation and 9 cases with two-stage operation. The post-operative favorable outcome was estimated in 13 cases(54%), the surgical mortality was 13%. There was no statistical difference between two groups.