Subarachnoid hemorrhage resulting from a burst intracranial aneurysm is a kind of stroke that often results in death or lasting disability for most of the individuals it affects. For many years, experts believed that cerebral vasospasm, which was instigated by the volume of blood present in the basal cisterns, was responsible for the delayed cerebral ischemia often seen after the hemorrhage. Around 70% of those who suffer from a subarachnoid hemorrhage go on to develop vasospasm. Moreover, up to 40% of these patients suffer from a secondary infarction, and interestingly, some of them don't even show signs of vasospasm.
Despite the frequency of vasospasm in these patients, treatments aimed specifically at counteracting vasospasm in the large cerebral arteries haven't been effective in reducing death rates or improving long-term outcomes. On the other hand, the prophylactic use of the calcium channel blocker, nimodipine, has shown promise. While it doesn't directly impact the cerebral vessels, it has been observed to reduce the risk of poor outcomes by a significant one-third.
Within 24 to 48 hours after a hemorrhage, the standard practice is to seal off the problematic aneurysm. This can be achieved through surgical clipping or endovascular coiling. When both options are available, coiling is usually the preferred method. There have been mixed results when trying to drain blood from the basal cisterns, believed to be the trigger for vasospasm, using techniques like surgical interventions, cisternal drainage, and external ventricular drainage.
In previous retrospective studies, a procedure that proactively drains cerebrospinal fluid via the lumbar route seemed to produce better patient outcomes. The thought behind this is that gravity might help in more efficiently clearing away blood and its byproducts. However, a prospective study named the Lumbar Drainage in Subarachnoid Haemorrhage (LUMAS) trial, which enrolled 210 participants, couldn't validate the benefits of lumbar drains. Upon reflection, this trial may have chosen patients who had a lower risk of complications, hence making it potentially less effective in discerning a significant benefit [1].
The EARLYDRAIN trial, a multicenter randomized clinical study conducted across 19 centers in Germany, Switzerland, and Canada, investigated the efficacy of early lumbar cerebrospinal fluid drainage in patients following aneurysmal subarachnoid hemorrhage. Out of 287 analyzed patients, 144 received an additional lumbar drain post-aneurysm treatment, while 143 received standard care. The primary measure was unfavorable outcomes six months after the hemorrhage, identified using the modified Rankin Scale score. Results showed that 32.6% of patients in the lumbar drain group, compared to 44.8% in the standard care group, had unfavorable neurological outcomes. Additionally, lumbar drain-treated patients had fewer secondary infarctions upon discharge. The study concluded that prophylactic lumbar drainage post-aneurysmal subarachnoid hemorrhage reduced secondary infarction occurrences and led to better outcomes at the 6-month mark [2].
Although both groups had similar volumes of cerebrospinal fluid drainage, a striking visual difference was observed in the fluid color between the ventricular and lumbar drains. The lumbar drain's fluid appeared darker and more reddish, indicating a higher concentration of blood and its degradation products. This observation underscores the sedimentation of erythrocytes in the fluid, suggesting that lumbar drainage may be more effective at removing these components.
The trial faced several limitations. A significant number of patients in the lumbar drain group didn't receive the designated intervention, although the intention-to-treat analysis was consistent even when considering this discrepancy. The lack of blinding among patients, their relatives, and acute care clinicians introduced potential bias, though blinded assessments of outcomes tried to mitigate this. The study did not collect data on factors such as preexisting hypertension, initial CT scan details regarding clot thickness and blood quantity, or medical complications commonly seen in subarachnoid hemorrhage patients. Additionally, potential treatments like clot thrombolysis or subarachnoid space irrigation were not explored, nor did the trial evaluate the benefits of higher drainage rates than the recommended 5 mL per hour, even though some patients exhibited higher lumbar drainage amounts.
In conclusion, despite some limitations, the findings of the EARLYDRAIN trial, early lumbar cerebrospinal fluid drainage should be considered for patients following an aneurysmal subarachnoid hemorrhage, to potentially enhance neurological outcomes and reduce secondary infarction risks.
REFERENCES:
Al-Tamimi YZ, Bhargava D, Feltbower RG, et al. Lumbar drainage of cerebrospinal fluid after aneurysmal subarachnoid hemorrhage: a prospective, randomized, controlled trial (LUMAS). Stroke. 2012;43(3):677-682. [PubMed]
Wolf S, Mielke D, Barner C, et al. Effectiveness of Lumbar Cerebrospinal Fluid Drain Among Patients With Aneurysmal Subarachnoid Hemorrhage: A Randomized Clinical Trial. JAMA Neurol. 2023;80(8):833–842 [Article Link]