Incidence of Aneurysmal Subarachnoid Hemorrhage and Analysis of Factors Involved in Early Aneurysm Rebleeding

Abstract

Background and Objectives: The incidence of subarachnoid hemorrhage (SAH) has been very low in earlier studies conducted at Shiraz University compared with reports in the literature. We determined the incidence in our study and compared it to an earlier study and international statistics. In the other part of our study, we examine the factors that contribute to the rerupture of cerebral aneurysms.Method: During 3 years from 2006 to 2009 (1385 to 1388), we handled 230 subarachnoid hemorrhage patients referring to Namazi hospital and recorded their data of age, GCS, count and size and location of aneurysms, and abnormal CT findings. We examined the effect of these factors on early rebleeding with w 2 and t tests.Results: The incidence of SAH in a earlier study conducted at Shiraz University 10 years ago was 0.7 per 100,000 persons per year. Incidence has risen in our study to 1.3 per 100,000 persons per year, which is still much lower than the incidence reported in developed countries, which is nearly 10 per 100,000 persons per year. Of 162 patients with aneurysmal SAH 17 patients rebled before surgery within 48 hours of admission. We found a significant relationship between GCS on admission, size of aneurysm, and intracerebral hemorrhage in first CT scan and early aneurysm rebleeding (P-values less than 0.05).Conclusions: Our lower incidence compared with developed countries could be owing to our younger population, fewer diagnostic facilities distributed in the regions, and a very larger geographic area we are sampling from with 1 referral center. On the other aspect, we suggest paying particular attention to those patients who have large aneurysms, who present with intracerebral hemorrhage in CT scan, and who are in poor clinical grade on admission. Surgery must be done on an emergency basis for these patients to prevent mortality and morbidity.

Benefits of early aneurysm surgery: Southern Iran experience

“…Mortality rate, once reported to be as high as 40%,[1] and later calculated to be about 20%, is now reported to be about 14%, regardless of the significant increase in the number of high-grade patients (Hunt and Hess grade 4 and 5). Acute phase rebleeding used to occur in 10.5% of patients[1] while the incidence is now 1-2%, occurring most commonly in patients who have been referred with delay after 72 h. Interestingly, a significant number of rebleeding cases have occurred at the time or just before craniotomy.…”

“…[2125] An earlier study performed in our department showed that the rate of SAH was approximately one per 100,000 population. [133] New data suggest an annual rate of 2 per 100,000, which is still much less than the reported worldwide rate of 10 per 100,000. [25] Such an increase is mainly due to better diagnosis and referral.…”