Hydrocephalus after aneurysmal subarachnoid hemorrhage
Hydrocephalus complicates the clinical course of greater than 20% of patients with aneurysmal subarachnoid hemorrhage 1) 2) , and its onset can be acute, within 48 hours after SAH, or rarely chronic, occurring in a delayed fashion weeks and even months after the hemorrhage.
The etiology of hydrocephalus following aSAH has yet to be fully elucidated, but is likely to include the following: obstruction of CSF flow within the basal cisterns and/or ventricles by clotted blood, diminished absorption at the arachnoid granulations, and inflammation 3) 4) 5) 6).
Na et al. found that higher sodium, lower potassium, and higher glucose levels were predictive values for shunt-dependent hydrocephalus from postoperative day (POD) 1 to POD 12-16 after subarachnoid hemorrhage. Strict correction of electrolyte imbalance seems necessary to reduce shunt-dependent hydrocephalus. Further large studies are warranted to confirm the findings 7).
Data suggest that the volume of the third ventricle in the initial CT is a strong predictor for shunt dependency after aSAH 8).
Early recognition of its signs and symptoms and accurate interpretation of computed tomography (CT) studies are important for the management of patients with SAH. Clinically, a poor neurologic grade has the highest correlation with an increased incidence of hydrocephalus. Radiographically, the bicaudate index on CT studies has emerged as the best marker of this condition. Although further studies are needed to understand the complex pathophysiology of this condition, hydrocephalus after SAH can be treated effectively using current technology 9).
Most readmissions after aneurysmal subarachnoid hemorrhage (SAH) relate to late consequences of hemorrhage, such as hydrocephalus, or medical complications secondary to severe neurological injury. Although a minority of readmissions may potentially be avoided with closer medical follow-up in the transitional care environment, readmission after SAH is an insensitive and likely inappropriate hospital performance metric 10).
Hydrocephalus might cause gradual obtundation in the first few hours or days; it can be treated by lumbar puncture or ventricular drainage, dependent on the site of obstruction
Aneurysmal subarachnoid hemorrhage (SAH) has been reported to induce an intrathecal inflammatory reaction reflected by cytokine release, particularly interleukin-6 (IL-6), which correlates with early brain damage and poor outcome.
Hydrocephalus leads to prolonged hospital and ICU stays, well as to repeated surgical interventions, readmissions, and complications associated with ventriculoperitoneal shunts, including shunt failure and shunt infection. Whether variations in surgical technique at the time of aneurysm treatment may modify rates of shunt dependency remains a matter of debate 13).
The indication for and the timing of a permanent shunt operation in patients following acute hydrocephalus (HC) after subarachnoid hemorrhage (SAH) remains controversial because risk factors for chronic HC fail to predict permanent shunt dependency. The amount of cerebrospinal fluid (CSF) drained via an external ventricular drain (EVD) may predict shunt dependency.
Results suggest that the daily amount of external CSF drainage volume in the acute state of SAH might influence the development of HC 14).
CSF IL-6 values of ≥10,000 pg/ml in the early post-SAH period may be a useful diagnostic tool for predicting shunt dependency in patients with acute posthemorrhagic hydrocephalus. The development of shunt-dependent posthemorrhagic hydrocephalus remains a multifactorial process 15).
Reliable prognostic tools to estimate the case fatality rate (CFR) and the development of chronic hydrocephalus (CHC) in aneurysmal subarachnoid hemorrhage (SAH) are not well defined.
Graeb Score or LeRoux score improve the prediction of shunt dependency and in parts of CFR in aneurysmal SAH patients therefore confirming the relevance of the extent and distribution of intraventricular blood for the clinical course in SAH 16).
One-hundred and fifty-two patients who had undergone an operation for SAH were enrolled in this study. Clinical data, radiological data, and procedural data were investigated. Procedural data included the operating technique (clipping vs. EVT) and the use of additional procedures (no procedure, lumbar drainage, or EVD). Delayed hydrocephalus was defined as a condition in which the Evan’s index was 0.3 or higher, as assessed using brain computed tomography more than 2 weeks after surgery, requiring shunt placement due to neurological deterioration.
Of the 152 patients, 45 (29.6%) underwent surgical clipping and 107 (70.4%) underwent EVT. Twenty-five (16.4%) patients developed delayed hydrocephalus. Age (p = 0.019), procedure duration (p = 0.004), and acute hydrocephalus (p = 0.030) were significantly correlated with the incidence of delayed hydrocephalus. However, the operation technique (p = 0.593) and use of an additional procedure (p = 0.378) were not significantly correlated with delayed hydrocephalus incidence.
No significant difference in the incidence of delayed hydrocephalus was associated with operation technique or use of an additional procedure in patients with SAH. However, delayed hydrocephalus was significantly correlated with old age, long procedural duration, and acute hydrocephalus. Therefore, they recommend that additional procedures should be discontinued as soon as possible 17).
Winkler et al. conducted a retrospective review of 663 consecutive patients with aSAH treated from 2005 to 2015 by open microsurgery via a pterional or orbitozygomatic craniotomy by the senior author (M.T.L.). Data collected from review of the electronic medical record included age, Hunt and Hess grade, Fisher grade, need for an external ventricular drain, and opening pressure. Patients were stratified into those undergoing no fenestration and those undergoing tandem fenestration of the LT and MoL at the time of surgical repair. Outcome variables, including VP shunt placement and timing of shunt placement, were recorded and statistically analyzed. RESULTS In total, shunt-dependent hydrocephalus was observed in 15.8% of patients undergoing open surgical repair following aSAH. Tandem microsurgical fenestration of the LT and MoL was associated with a statistically significant reduction in shunt dependency (17.9% vs 3.2%, p < 0.01). This effect was confirmed with multivariate analysis of collected variables (multivariate OR 0.09, 95% CI 0.03-0.30). Number-needed-to-treat analysis demonstrated that tandem fenestration was required in approximately 6.8 patients to prevent a single VP shunt placement. A statistically significant prolongation in days to VP shunt surgery was also observed in patients treated with tandem fenestration (26.6 ± 19.4 days vs 54.0 ± 36.5 days, p < 0.05). CONCLUSIONS Tandem fenestration of the LT and MoL at the time of open microsurgical clipping and/or bypass to secure ruptured anterior and posterior circulation aneurysms is associated with reductions in shunt-dependent hydrocephalus following aSAH. Future prospective randomized multicenter studies are needed to confirm this result 18).
181 participants with a mean age of 54.4 years. Higher sodium (hazard ratio, 1.53; 95% confidence interval, 1.13-2.07; p = 0.005), lower potassium, and higher glucose levels were associated with higher shunt-dependent hydrocephalus. The receiver operating characteristic curve analysis showed that the areas under the curve of sodium, potassium, and glucose were 0.649 (cutoff value, 142.75 mEq/L), 0.609 (cutoff value, 3.04 mmol/L), and 0.664 (cutoff value, 140.51 mg/dL), respectively.
Despite the exploratory nature of this study, we found that higher sodium, lower potassium, and higher glucose levels were predictive values for shunt-dependent hydrocephalus from postoperative day (POD) 1 to POD 12-16 after subarachnoid hemorrhage. Strict correction of electrolyte imbalance seems necessary to reduce shunt-dependent hydrocephalus. Further large studies are warranted to confirm our findings 19).
The study is designed to determine the efficacy of lamina terminalis fenestration on the reduction of SDH after aneurysm clipping.
METHODS/DESIGN: A total of 288 patients who meet the inclusion criteria will be randomized into single aneurysm clipping or aneurysm clipping plus FLT in the Department of Neurosurgery, West China Hospital. Follow-up was performed 1, 3, 6, and 12 months after aneurysm clipping. The primary outcome is the incidence of SDH and the secondary outcomes include cerebral vasospasm, functional outcome evaluated by the modified Rankin Scale and Extended Glasgow Outcome Scale, and mortality.
DISCUSSION: The FISH trial is a large randomized, parallel controlled clinical trial to define the therapeutic value of FLT, the results of which will help to guide the surgical procedure and resolve the long-puzzled debate in the neurosurgical community.
CONCLUSIONS: This protocol will determine the efficacy of FLT in the setting of aneurysmal subarachnoid hemorrhage 20).
Seven hundred eighteen patients with aneurysmal subarachnoid hemorrhage who were treated between 1990 and 1999 were retrospectively studied, to identify factors contributing to shunt-dependent hydrocephalus. With these data, a stepwise logistic regression procedure was used to determine the effect of each variable on the development of hydrocephalus and to create a scoring system.
Overall, 152 of the 718 patients (21.2%) underwent shunting procedures for treatment of hydrocephalus. Four hundred seventy-nine of the patients (66.7%) were female. Of the factors investigated, the following were associated with shunt-dependent hydrocephalus, as determined with a variety of statistical methods: 1) increasing age (P < 0.001), 2) female sex (P = 0.015), 3) poor admission Hunt and Hess grade (P < 0.001), 4) thick subarachnoid hemorrhage on admission computed tomographic scans (P < 0.001), 5) intraventricular hemorrhage (P < 0.001), 6) radiological hydrocephalus at the time of admission (P < 0.001), 7) distal posterior circulation location of the ruptured aneurysm (P = 0.046), 8) clinical vasospasm (P < 0.001), and 9) endovascular treatment (P = 0.013). The presence of intracerebral hematomas, giant aneurysms, or multiple aneurysms did not influence the development of shunt-dependent hydrocephalus.
The results of this study can help identify patients with a high risk of developing shunt-dependent hydrocephalus. This may help neurosurgeons expedite treatment, may decrease the cost and length of hospital stays, and may result in improved outcomes 21).
In 138 patients with ruptured cerebral aneurysms operated on within 48 to 72 hours after subarachnoid hemorrhage, an external ventricular drainage catheter was inserted before craniotomy and was used intermittently during the first week after surgery. In 51 patients, intracranial pressure (ICP) was measured intraoperatively. The majority of patients showed increased ICP intraoperatively irrespective of the preoperative Hunt and Hess grade and the amount of subarachnoid blood accumulation or intraventricular blood clot. Intraoperative drainage of cerebrospinal fluid allowed easy access for aneurysm dissection by making the brain slack in more than 90% of patients. Postoperative ICP measurements revealed that significant brain swelling did not occur in the majority of patients. In 7 patients, persistently elevated ICP (greater than 20 mm Hg) was recorded. Nine patients (8%) developed shunt-dependent hydrocephalus; all of these patients had suffered an intraventricular hemorrhage. Measurements of the volumes of cerebrospinal fluid drained did not allow prediction of shunt-dependent hydrocephalus 22).
The incidence and clinical aspects of acute hydrocephalus were examined in 200 patients with recently ruptured intracranial aneurysms. The following conclusions were reached: Acute hydrocephalus is an important complication of aneurysmal subarachnoid hemorrhage that occurs in approximately 20% of all cases and exhibits an incidence that tends to parallel clinical grade (Grade I, 3%; Grade II, 5%; “Good” Grade III, 21%; “Bad”Grade III, 40%; Grade IV, 42%; Grade V, 26%). Impaired consciousness leading to a general downgrading of clinical status was the predominant clinical finding (93%), but neither this nor other nonspecific signs of increased intracranial pressure were distinguishable from the effects of the precipitating hemorrhage. The computed tomographic signs of acute hydrocephalus are distinctive and consist of selective ballooning of the frontal horns, rostral-caudal enlargement of the cerebral ventricles, and a halo of periventricular hyperdensity (edema) that evolves in sequence with ventricular changes. The treatment of choice is external ventricular drainage, which results in prompt and often dramatic improvement in approximately two-thirds of the patients 23).
Hydrocephalus, defined as a bicaudate index above the 95th percentile for age, was found in 34 (20%) of 174 prospectively studied patients with subarachnoid hemorrhage (SAH) who survived the first 24 hours and who underwent computerized tomography (CT) scanning within 72 hours. The occurrence of acute hydrocephalus was related to the presence of intraventricular blood, and not to the extent of cisternal hemorrhage. The level of consciousness was depressed in 30 of the 34 patients. Characteristic clinical features were present in 19 patients, including a gradual obtundation after the initial hemorrhage in 16 patients and small nonreactive pupils in nine patients (all with a Glasgow Coma Scale score of 7 or less). In the remaining 15 patients (44%), the diagnosis could be made only by CT scanning. After 1 month, 20 of the 34 patients had died: six from rebleeding (four after shunting), 11 from cerebral infarction (eight after an initial improvement), and three from other or mixed causes. Only one of nine patients in whom a shunt was placed survived, despite rapid improvement in all immediately after shunting. The mortality rate among patients with acute hydrocephalus was significantly higher than in those without, with the higher incidence caused by cerebral infarction (11 of 34 versus 12 of 140 cases, respectively; p less than 0.001). Death from infarction could not be attributed to the extent of cisternal hemorrhage, the use of antifibrinolytic drugs, or failure to apply surgical drainage, but could often be explained by the development of hyponatremia, probably accompanied by hypovolemia 24).
Seventeen patients suffering from SAH and/or intraventricular hemorrhage were studied; all were admitted in Grades II to V according to Hunt and Hess. Eleven patients had a proven aneurysm. The ICP, monitored via an intraventricular catheter, was above 15 mm Hg (2 kPa) during part of the monitoring period in all patients. B-waves at 1/min were noted in all patients. Resistance to outflow of CSF was determined by the following techniques: 1) bolus injection; 2) constant-rate steady-state infusion; or 3) controlled withdrawal (“inverse infusion”). Resistance to outflow of CSF was increased in all patients, ranging from 11.5 to 85 mm Hg/ml/min. The ICP was linearly correlated with outflow resistance. Four (50%) of the eight survivors required a shunt. Neither the presence of hydrocephalus on admission, nor the level of ICP, nor the magnitude of resistance to outflow of CSF was clearly related to the requirement of a permanent CSF diversion 25).