Response
Journal
Journal of Neurosurgery
Journal Volume
116
Journal Issue
6
Date Issued
2012
Author(s)
Abstract
Tsuang and colleagues4 explore the implications of contrast extravasation seen on hyperacute CT angiograms performed for the workup of subarachnoid hemorrhage (SAH). Based on their experience with 9 cases in which patients underwent CT angiography (CTA) at their institution within 2 hours of ictus, and another 12 cases culled from the literature in which most of the patients (10 of 12) underwent CTA, they conclude: 1) that outcomes in those with contrast extravasation tend to be poor, 2) that only patients who are classified as good grade prior to their CTAdocumented rebleeding are likely salvageable, and 3) that salvage in this initially good-grade population requires immediate microsurgical repair together with aggressive cranial decompression. With regard to the overall poor outcomes reported (76% of patients dead or in a vegetative state), these seem expected given that 82% of those patients with documentable findings from neurological examinations performed after the rebleeding were classified as WFNS Grade V, and 95% were classified as Grade IV or V. While the conclusions regarding salvageability seem equally plausible, the data are less convincing. For instance, although all 11 patients presenting in poor condition prior to the CTA-documented rebleeding died or were left vegetative, none of these patients actually underwent the immediate aggressive decompressive surgery the authors generally offered to those initially presenting in better condition. In addition, 5 of the 11 were over the age of 70 years and 3 were over 80. Thus while I share the authors’ pessimism, and a rebleeding episode of any type in a poor-grade patient certainly carries an extremely poor prognosis, I would like to see a sizable cohort of young patients whose cases were managed in a maximally aggressive manner before I’d be comfortable concluding futility. One also wonders whether the initially good-grade patients who rebled during CTA and became WFNS Grade V were salvaged because of the timely decompressive surgery or because they were actually not truly Grade V but rather “postictal.” Determining which is the case will require more patients, and even then it may be difficult. But for the time being, 3 good outcomes in 3 Grade V patients suggests that something else might be going on, especially given the less than miraculous outcomes seen with craniectomy in other poorgrade SAH populations.1 Two additional issues that bear some mention include the timing of the decompressive surgery and the timing of CTA. The authors suggest that it is the acuteness of the decompression that matters, yet their data suggest that even delayed decompression, as performed in Case 3, may be sufficient to achieve good outcome. This raises the possibility that endovascular repair followed by decompression may be reasonable in patients whose intracranial pressure can be acutely controlled. Whether this turns out to be the case or not will also require further study. Finally, the incidence of rebleeding during CTA in this study is very high (occurring in 9 [15%] of 62 patients).3 This is likely due to the fact that CTA was performed during a time frame when the incidence of rebleeding is highest, but a rate of 15% makes one wonder what percentage of all the rebleeding episodes occurred during CTA. If the percentage is alarmingly high, it is all the more interesting that less than 10% of the cases of intra-CTA rebleeding ever reported occurred beyond the hyperacute period (first 3 hours). While CTA tends to be one of those studies performed early in the course of care, one cannot help but wonder whether hyperacute CTA, like hyperacute angiography,2 might increase the likelihood of bleeding from a particularly unstable aneurysm. Although it is hard to imagine why, further studies are needed to examine whether CTA, particularly as performed in this study, is capable of causing alterations in blood pressure or transmural pressure. If so, there might be pharmacological maneuvers that could block this untoward physiological response and improve outcomes in centers where hyperacute scanning is common. (http://thejns.org/doi/abs/10.3171/2012.1.JNS112022)
SDGs
Type
note