Middle cerebral artery (MCA) aneurysms are 20% of saccular aneurysms. They are occasionally found incidentally or because of a mass effect, but most are found when they rupture8). After Dott2) treated ruptured aneurysms with surgical methods, many treatment modalities have been developed and reported17). When MCA aneurysms rupture, approximately 30-50% lead to a subarachnoid hemorrhage (SAH) combined with an intracerebral hemorrhage (ICH), with a mortality rate of 10-41%4,16). The mechanism of ICH developed by aneurysmal rupture is still controversial but the most commonly accepted hypothesis is that the ICH develops when fibrin, hematoma, or the fibrosis of the arachnoid membrane obstructs the subarachnoid space, or an aneurysm attached to the pia ruptures16). These ICHs are a risk factor for poor prognosis and surgical complications in ruptured MCA aneurysm patients. However, our clinical data suggested that patients with ruptured MCA aneurysms with ICH have a non-classical clinical course that requires further study. Therefore, authors analyzed the relationship between multiple clinical factors of ruptured MCA aneurysms with ICH and general prognosis, to help predict the results of surgical treatment.

We retrospectively reviewed 68 patients with MCA aneurysm who underwent neck clipping after aneurysm rupture between January 2006 and December 2010. We excluded 27 patients who did not have accompanying ICH. The remaining 41 patients with accompanying ICH were evaluated. Aneurysm, SAH and ICH were diagnosed with computed tomography (CT) and conventional cerebral angiography. Of the 41 total patients, 27 were evaluated with preoperative angiography (Table 1).

Niikawa et al.13) reported that intracranial pressure elevation and brain injury in ruptured MCA with ICH patients are directly correlated with hematoma size and location15,18). And, patients with ruptured MCA with associated ICH were reported to have a high mortality rate8). ICH is more common with distal anterior cerebral artery aneurysms. Since the frequency of ruptured distal anterior cerebral artery aneurysm is low, aneurysms on the MCA or anterior communicating artery are the most common for accompanying ICH8). When there were ruptured MCA aneurysms, Niikawa et al.13) reported that 36% of SAH patients also had ICH. According to the domestic report, Lee et al.9) reported a slightly higher rate. Nowak et al.14) reported a mortality rate of 36% for ruptured aneurysm with ICH, with domestic statistics on mortality rate slightly lower, at 2.3-8.3%10). This study excluded patients with absence of brain stem function and perfusion defect; thus, the exact mortality rate was not determined. The most common causes of death are sudden elevation of intracranial pressure, and a midline shift of brain parenchyma from a mass effect1,15).

It is generally believed hat ruptured MCA aneurysms with ICH will have a worse prognosis than ruptured MCA aneurysms with SAH only18). The larger the hematoma volume, the more mass effect on the adjacent brain parenchyma. Hence, more severe brain damage is inevitable. Our study analyzed the correlation among multiple parameters such as gender, initial mental status, age, and radiologic factors and lesion lateralization, hematoma volume, location, midline shift, postoperative volume of residual hematoma, and prognosis.

No significant correlation was seen among the parameters of gender, lesion lateralization, or clinical outcome. According to the previous literature, Kazumata et al.7) and Kim et al.8) also analyzed the relationships among the same parameters in conjunction with for clinical outcome, and found no significant correlations. Younger patients had a better clinical outcome than older patients in this study. Positive correlation was seen for age and prognosis for ICH in the frontal lobe or sylvian fissure, but no significant conclusions were drawn for ICH in the temporal lobe. When we set the volume of hematoma as a fixed parameter to determine the patient's prognosis, younger age patients had more favorable clinical outcome in the study group with minimal volume of hematoma as it was proven statistically significant (p<0.05). On the other hand, one cannot guarantee that elderly SAH patients with a large amount of ICH on the temporal lobe will all have poor clinical outcome. A poor prognosis must not be the first and absolute parameter when making the decision for the surgical treatment.

The better the initial mental status at admission, the more favorable clinical outcome was observed (p<0.05) as this was mentioned in the previous literature5,12). In this study, the positive correlation between good initial mental status and a good prognosis was statistically valid only in the patient group with ICH located on the temporal lobe. As many previous reports have discussed, there was the direct correlation between the prognosis of ruptured aneurysm with ICH and the initial mental status3,11). A new design of study with a larger study population is necessary to re-analyze the data statistically in the near future.

There was no definite difference in the clinical outcome when the determining factor was the ICH location. However, Lee et al.9) reported that patients with ICH located on the temporal lobe showed a more favorable prognosis. Whereas Kim et al.8) reported that the same favorable result was observed from the patients with the ICH located in the sylvian fissure. Although results were not statistically significant, our study showed that those with ICH on the temporal lobe showed a better clinical prognosis. A midline shift on brain CT was another critical factor to determine a patient's prognosis due to its mass effect. When we set the cut-off value for a midline shift as 4.5 mm, 95.5% of patients had a favorable clinical outcome when the midline shift was less than 4.5 mm. However, when it was more than 4.5 mm, 42.1% patients showed a poor clinical outcome, although it comprised a relatively low percentage in the total population. In a similar manner, if we set the hematoma volume fixed to 31 mL, specificity and sensitivity was the highest. If the hematoma volume was less than 31 mL, 91.7% of the patients showed a better clinical outcome. However, if the hematoma volume was more than 31 mL, a relatively small proportion of patients (41.2%) had unfavorable outcome. Therefore, it was expected that the patients with minimal hematoma volume showed a more favorable surgical outcome. Nevertheless, even if the patients had a larger volume of hematoma with a midline shift, this should not be an absolute criterion to determine a patient's prognosis to give up the surgical treatment. In summary, the less the residual hematoma volume, the better the patient prognosis, as the hemorrhage itself significantly influenced to cause cerebral edema, vasospasm, and multiple brain injury. This study also demonstrated that the patients with less residual hematoma volume showed a more favorable prognosis. Yet, it was obvious that the patients with minimal residual hematoma volume showed a less favorable prognosis than those without ICH. The surgical intervention definitely prevents the secondary brain injury. Nonetheless, it is important to consider that initial brain injury was more critical in those with ICH than those without.

This study demonstrated that predictors of a good prognosis for ruptured MCA aneurysm were under 65 years old, had good initial mental status, a preoperative hematoma volume below 31 mL, and a midline shift of less than 4.5 mm. These predictors were important in determining the prognosis of surgical outcome. However, also important to note was that patients without good prognostic factors did not necessarily proceed to poor surgical outcome, as this probability was relatively low. Thus, neurosurgeons are encouraged to recommend an early intervention of surgical treatment even for patients who show poor prognosis, as many interrelated factors influence the clinical outcome.