Ethnic differences in the distribution of posterior circulation aneurysms

Abstract

Ten percent to 20 of aneurysms are located in the posterior circulation. To test the hypothesis that there are ethnic differences in both the prevalence and distribution of these aneurysms, we retrospectively reviewed all aneurysms treated at our public and private referral hospitals, Los Angeles County General Hospital and University of Southern California university Hospital, over an 11-year period. Seven hundred and seventy four patients with 951 aneurysms were included in this study. Of the patients in our regional referral base, 89 white patients had aneurysms, 20 (22.5) of whom had at least 1 posterior circulation lesion; 232 Hispanic patients had aneurysms, 17 (7.3) of whom had posterior circulation lesions; 79 African-American patients had aneurysms, 6 (7.6) of whom had posterior circulation lesions; and 45 Asian patients had aneurysms, 6 (13.3) of whom had posterior circulation lesions. Aneurysm distribution also differed by ethnicity. Considering patients from all hospitals, 42 (52) of 81 posterior circulation, aneurysms were at the basilar tip in the white population. In contrast, only 3 of 26 posterior circulation aneurysms in Hispanics were located at the basilar tip (P<.001). Aneurysms in both the Hispanic and Asian cohorts were weighted towards the vertebrobasilar junction. Significant differences exist in both the prevalence and distribution of posterior circulation aneurysms with regard to ethnicity. In particular, basilar tip aneurysms are uncommon in our Hispanic population. Similarities in aneurysm distribution between Asians and Hispanics may be related to common ancestry. It is likely that genetic factors play a significant role in the predilection for aneurysms in different locations within the posterior fossa. Ten percent to 20 of aneurysms are located in the posterior circulation. To test the hypothesis that there are ethnic differences in both the prevalence and distribution of these aneurysms, we retrospectively reviewed all aneurysms treated at our public and private referral hospitals, Los Angeles County General Hospital and University of Southern California university Hospital, over an 11-year period. Seven hundred and seventy four patients with 951 aneurysms were included in this study. Of the patients in our regional referral base, 89 white patients had aneurysms, 20 (22.5) of whom had at least 1 posterior circulation lesion; 232 Hispanic patients had aneurysms, 17 (7.3) of whom had posterior circulation lesions; 79 African-American patients had aneurysms, 6 (7.6) of whom had posterior circulation lesions; and 45 Asian patients had aneurysms, 6 (13.3) of whom had posterior circulation lesions. Aneurysm distribution also differed by ethnicity. Considering patients from all hospitals, 42 (52) of 81 posterior circulation, aneurysms were at the basilar tip in the white population. In contrast, only 3 of 26 posterior circulation aneurysms in Hispanics were located at the basilar tip (P<.001). Aneurysms in both the Hispanic and Asian cohorts were weighted towards the vertebrobasilar junction. Significant differences exist in both the prevalence and distribution of posterior circulation aneurysms with regard to ethnicity. In particular, basilar tip aneurysms are uncommon in our Hispanic population. Similarities in aneurysm distribution between Asians and Hispanics may be related to common ancestry. It is likely that genetic factors play a significant role in the predilection for aneurysms in different locations within the posterior fossa.