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Correlation between tomographic scales and vasospasm and delayed cerebral ischemia in aneurysmal subarachnoid hemorrhage

ABSTRACT

Objective:

To determine the prevalence of sonographic vasospasm and delayed ischemic deficit in patients with aneurysmal subarachnoid hemorrhage, to evaluate the correlation between different tomographic scales and these complications, and to study prognostic factors in this group of patients.

Methods:

This was a prospective study of patients admitted to the intensive care unit with a diagnosis of aneurysmal subarachnoid hemorrhage. The prevalence of sonographic vasospasm and radiological delayed cerebral ischemia was analyzed, as was the correlation between different tomographic scales and these complications.

Results:

A total of 57 patients were studied. Sixty percent of the patients developed sonographic vasospasm, which was significantly associated with delayed cerebral ischemia and mortality. The Claassen and Hijdra scales were better correlated with the development of cerebral vasospasm (areas under the curve of 0.78 and 0.68) than was Fisher’s scale (0.62). Thirty-two patients (56.1%) developed cerebral infarction on CT; the significantly associated factors were poor clinical grade at admission (p = 0.04), sonographic vasospasm (p = 0.008) and severity of vasospasm (p = 0.015). Only the semiquantitative Hijdra scale was significantly correlated with the development of radiological delayed cerebral ischemia (p = 0.009). The patients who presented cerebral infarction had worse neurological evolution and higher mortality.

Conclusion:

This is the first study in our environment on the subject. The Claassen and Hijdra tomographic scales showed better prognostic performance than the Fisher scale for the development of cerebral vasospasm. The finding of sonographic vasospasm could be a noninvasive criterion for the early detection of delayed cerebral ischemia and neurological deterioration in patients with aneurysmal subarachnoid hemorrhage.

Keywords:
Vasospasm; intracranial; Subarachnoid hemorrhage; X-ray; computed tomography; Brain ischemia

RESUMO

Objetivo:

Determinar la prevalencia de vasoespasmo sonográfico y déficit isquémico diferido en pacientes con hemorragia subaracnoidea aneurismática, evaluar la correlación entre las diferentes escalas tomográficas con dichas complicaciones, así como estudiar los factores pronósticos en este grupo de pacientes.

Métodos:

Estudio prospectivo de pacientes ingresados a la unidad de cuidados intensivos con diagnóstico de hemorragia subaracnoidea aneurismática. Se analizó la prevalencia de vasoespasmo sonográfico e isquemia cerebral diferida radiológica, así como la correlación entre diferentes escalas tomográficas con dichas complicaciones.

Resultados:

Se estudiaron 57 pacientes. El 60% de los pacientes desarrollaron vasoespasmo sonográfico, el cual se asoció significativamente con isquemia cerebral diferida y mortalidad. Las escalas de Claassen y de Hijdra tuvieron una mejor correlación con el desarrollo de vasoespasmo cerebral (área bajo la curva de 0,78 y 0,68) que la de Fisher (0,62). Treinta y dos pacientes (56,1%) desarrollaron infarto cerebral en la TC, siendo los factores que se asociaron en forma estadísticamente significativa al mismo: pobre grado clínico al ingreso (p = 0,04), vasoespasmo sonográfico (p = 0,008) y severidad del vasoespasmo (p = 0,015). Solamente la escala semicuantitativa de Hijdra se correlacionó significativamente con el desarrollo de isquemia cerebral diferida radiológica (p = 0,009). Los pacientes que presentaron infarto cerebral tuvieron peor evolución neurológica y mayor mortalidad.

Conclusion:

Se presenta el primer estudio en nuestro medio sobre el tema. Las escalas tomográficas de Claassen y Hijdra presentaron un mejor rendimiento pronóstico que la de Fisher para desarrollo de vasoespasmo cerebral. El hallazgo de vasoespasmo sonográfico podría ser un criterio no invasivo de detección temprana de isquemia cerebral diferida y peoría neurológica en los pacientes con hemorragia subaracnoidea aneurismática.

Descriptores:
Vasoespasmo intracraneal; Hemorragia subaracnoidea; Tomografia computadorizada por rayos X; Isquemia encefálica

INTRODUCTION

Subarachnoid hemorrhage (SAH) is a devastating neurological disease, accounting for 5% of all strokes.(11 Rouanet C, Silva GS. Subarachnoid hemorrhage: concepts and updates. Arq Neuropsiquiatr. 2019;77(11):806-14.) Despite advances in its medical and surgical management, SAH is associated with high mortality and morbidity, with serious sequelae that affect up to half of the patients.(22 Rabinstein AA, Lanzino G. Aneurysmal subarachnoid hemorrhage: unanswered questions. Neurosurg Clin N Am. 2018;29(2):255-62.

3 Lantigua H, Ortega-Gutierrez S, Schmidt JM, Lee K, Badjatia N, Agarwal S, et al. Subarachnoid hemorrhage: who dies, and why? Crit Care. 2015;19(1):309.
-44 Grille P, Gallo JL, Panzardo H, Vazquez R, Bagnulo H. Identificación de problemas en el manejo médico-quirúrgico de la hemorragia subaracnoidea. Arch Instit Neurol. 2001;4:104-10.)

Delayed cerebral ischemia is one of the main complications of SAH, with an incidence greater than 30%. It is a complex process, the definition of which continues to be debated. Its etiology includes multiple pathophysiological mechanisms, such as early brain injury, vasospasm, inflammation, microthrombosis, alterations in cerebral autorregulation, microcirculation dysfunction, and cortical spreading depression.(55 Macdonald RL. Pathophysiology and molecular genetics of vasospasm. Acta Neurochir Suppl. 2001;77:7-11.

6 Alsbrook DL, Di Napoli M, Bhatia K, Desai M, Hinduja A, Rubinos CA, et al. Pathophysiology of early brain injury and its association with delayed cerebral ischemia in aneurysmal subarachnoid hemorrhage: a review of current literature. J Clin Med. 2023;12(3):1015.

7 Geraghty JR, Testai FD. Delayed cerebral ischemia after subarachnoid hemorrhage: beyond vasospasm and towards a multifactorial pathophysiology. Curr Atheroscler Rep. 2017;19(12):50.

8 Cossu G, Messerer M, Oddo M, Daniel RT. To look beyond vasospasm in aneurysmal subarachnoid haemorrhage. Biomed Res Int. 2014;2014:628597.

9 Frontera JA, Fernandez A, Schmidt M, Claassen J, Wartenberg KE, Badjatia N, et al. Defining vasospasm after subarachnoid hemorrhage: what is the most clinically relevant definition? Stroke. 2009;40(6):1963-8.
-1010 Washington CW, Zipfel GJ; Participants in the International Multi-disciplinary Consensus Conference on the Critical Care Management of Subarachnoid Hemorrhage. Detection and monitoring of vasospasm and delayed cerebral ischemia: a review and assessment of the literature. Neurocrit Care. 2011;15(2):312-7.)

The amount and topography of the blood present in the initial computed tomography (CT) scan constitutes a major risk factor in the development of cerebral vasospasm. Different tomographic scales have been developed that correlate the entity and topography of bleeding with the risk of presenting vasospasm, delayed cerebral ischemia and/or cerebral infarction.(1111 Fisher CM, Kistler JP, Davis JM. Relation of cerebral vasospasm to subarachnoid hemorrhage visualized by computerized tomographic scanning. Neurosurgery. 1980;6(1):1-9.

12 Smith ML, Abrahams JM, Chandela S, Smith MJ, Hurst RW, Le Roux PD. Subarachnoid hemorrhage on computed tomography scanning and the development of cerebral vasospasm: the Fisher grade revisited. Surg Neurol. 2005;63(3):229-34; discussion 234-5.

13 Frontera JA, Claassen J, Schmidt JM, Wartenberg KE, Temes R, Connolly ES Jr, et al. Prediction of symptomatic vasospasm after subarachnoid hemorrhage: the modified fisher scale. Neurosurgery. 2006;59(1):21-7; discussion 21-7.

14 Inagawa T, Shibukawa M, Hidaka T. A comparison of computed tomography-based scales with and without consideration of the presence or absence of intraventricular hemorrhage in patients with aneurysmal subarachnoid hemorrhage. World Neurosurg. 2018;114:e926-37.

15 van der Steen WE, Leemans EL, van den Berg R, Roos YB, Marquering HA, Verbaan D, et al. Radiological scales predicting delayed cerebral ischemia in subarachnoid hemorrhage: systematic review and meta-analysis. Neuroradiology. 2019;61(3):247-56.

16 Qureshi AI, Sung GY, Razumovsky AY, Lane K, Straw RN, Ulatowski JA. Early identification of patients at risk for symptomatic vasospasm after aneurysmal subarachnoid hemorrhage. Crit Care Med. 2000;28(4):984-90.

17 Forsell A, Larsson C, Ro Nnbarg J, Fodstad H. CT assessment of subarachnoid haemorrhage: a comparison between different CT methods of grading subarachnoid haemorrhage. Br J Neurosurg. 1995;9(1):21-7.
-1818 Friedman JA, Goerss SJ, Meyer FB, Piepgras DG, Pichelmann MA, McIver JI, et al. Volumetric quantification of Fisher grade 3 aneurysmal subarachnoid hemorrhage: a novel method to predict symptomatic vasospasm on admission computerized tomography scans. J Neurosurg. 2002;97(2):401-7.)

The objectives of this study were to determine the prevalence of sonographic vasospasm and delayed ischemic deficit in patients with aneurysmal SAH, to evaluate the correlation between the different tomographic scales and these complications, and to study the prognostic factors in this group of patients.

METHODS

This prospective, single-center study was carried out in an intensive care unit (ICU) of the public health care sector in Uruguay; the center receives approximately 50 patients with SAH annually. The study period was between April 2020 and December 2022. The work was approved by the Ethics Committee of Hospital Maciel.

All patients were admitted to the ICU with a diagnosis of SAH of aneurysmal etiology. Patients under 18 years of age, those with an inaccessible or deficient cranial ultrasound window, and those who died within the first 72 hours were excluded. Patients whose initial CT scan was performed after 24 hours from the onset of symptoms were also excluded.

For data collection, the electronic clinical management computer system (Epimed Solutions®) was used, as were audited reviews of the clinical history of each patient, maintaining their confidentiality. The variables recorded were age, sex, clinical grade classification (Hunt and Hess and the World Federation of Neurosurgical Societies - WFNS) at admission, Simplified Acute Physiologic Score 3 (SAPS 3) score on admission, presence of main comorbidities associated with the development of vasospasm, such as high blood pressure, diabetes and smoking, location of the aneurysm, type of treatment (surgical clipping or embolization), length of stay in the ICU, Glasgow Outcome Score (GOS) and mortality at discharge from the ICU and hospital.

All patients were treated in accordance with the institutional protocol for the management of aneurysmal SAH, which included support of vital physiological systems to avoid hypoxemia, hypoand hypercapnia and arterial hypotension, transamine (until the aneurysm was stabilized and for a maximum of 72 hours), enteral nimodipine for 21 days, seizure prophylaxis with phenytoin or valproate for 7 days, and prophylaxis of gastrointestinal bleeding and venous thromboembolism. When vasospasm was associated with ischemic neurological deficit, arterial hypertension was induced with norepinephrine and, if no improvement was observed, endovascular treatment was administered if possible.(1919 Grille PM, Gallo JL, Panzardo H, Vázquez R, Bagnulo H. Hemorragia subaracnoidea en la unidad de cuidados intensivos: análisis de 97 casos clínicos. Rev Med Urug. 2001;17(2):114-8.)

Tomographic classification was performed using the first CT scan, completed within the first 24 hours of the onset of symptoms. The Fisher, Claassen and Hijdra tomographic scales were used to analyze the CT scan (Table 1).(1111 Fisher CM, Kistler JP, Davis JM. Relation of cerebral vasospasm to subarachnoid hemorrhage visualized by computerized tomographic scanning. Neurosurgery. 1980;6(1):1-9.,2020 Claassen J, Bernardini GL, Kreiter K, Bates J, Du YE, Copeland D, et al. Effect of cisternal and ventricular blood on risk of delayed cerebral ischemia after subarachnoid hemorrhage: the Fisher scale revisited. Stroke. 2001;32(9):2012-20.,2121 Hijdra A, Brouwers PJ, Vermeulen M, van Gijn J. Grading the amount of blood on computed tomograms after subarachnoid hemorrhage. Stroke. 1990;21(8):1156-61.) This evaluation was carried out by 2 researchers (MGH and PG) independently, and in case of disagreement, the opinion of a reference neuroimaging physician was used.(99 Frontera JA, Fernandez A, Schmidt M, Claassen J, Wartenberg KE, Badjatia N, et al. Defining vasospasm after subarachnoid hemorrhage: what is the most clinically relevant definition? Stroke. 2009;40(6):1963-8.,1414 Inagawa T, Shibukawa M, Hidaka T. A comparison of computed tomography-based scales with and without consideration of the presence or absence of intraventricular hemorrhage in patients with aneurysmal subarachnoid hemorrhage. World Neurosurg. 2018;114:e926-37.,1515 van der Steen WE, Leemans EL, van den Berg R, Roos YB, Marquering HA, Verbaan D, et al. Radiological scales predicting delayed cerebral ischemia in subarachnoid hemorrhage: systematic review and meta-analysis. Neuroradiology. 2019;61(3):247-56.)

Table 1
Tomographic scales for subarachnoid hemorrhage

The velocity of the cerebral blood flow was evaluated by means of blind digital transcranial Doppler (TCD) using a 2 MHz transducer (Digi-Lite TM, Rimed USA, Inc., Long Island City, NY). Both middle cerebral arteries (MCAs) were insonated through the transtemporal window, and both extracranial internal carotid arteries (ICAs) were insonated through the submandibular window. The Lindegaard index was calculated using the mean MCA/ACI velocity ratio.(1010 Washington CW, Zipfel GJ; Participants in the International Multi-disciplinary Consensus Conference on the Critical Care Management of Subarachnoid Hemorrhage. Detection and monitoring of vasospasm and delayed cerebral ischemia: a review and assessment of the literature. Neurocrit Care. 2011;15(2):312-7.,2222 Aaslid R, Huber P, Nornes H. Evaluation of cerebrovascular spasm with transcranial Doppler ultrasound. J Neurosurg. 1984;60(1):37-41.

23 Laumer R, Steinmeier R, Gönner F, Vogtmann T, Priem R, Fahlbusch R. Cerebral hemodynamics in subarachnoid hemorrhage evaluated by transcranial doppler sonography. Part 1. Reliability of flow velocities in clinical management. Neurosurgery. 1993;33(1):1-8; discussion 8-9.
-2424 Robba C, Cardim D, Sekhon M, Budohoski K, Czosnyka M. Transcranial Doppler: a stethoscope for the brain-neurocritical care use. J Neurosci Res. 2018;96(4):720-30.) Sonographic vasospasm was defined as the presence of a mean MCA velocity > 120cm/s and a Lindegaard index > 3. A mean MCA velocity between 120 and 149cm/s was classified as mild, a mean MCA velocity between 150 and 199cm/s was classified as moderate, and a mean MCA velocity ≥ 200cm/s and/or Lindegaard index > 6 was classified as severe.(2525 Lindegaard KF, Nornes H, Bakke SJ, Sorteberg W, Nakstad P. Cerebral vasospasm after subarachnoid haemorrhage investigated by means of transcranial doppler ultrasound. Acta Neurochir Suppl (Wien).1988;42:81-4.

26 Grosset DG, Straiton J, du Trevou M, Bullock R. Prediction of symptomatic vasospasm after subarachnoid hemorrhage by rapidly increasing transcranial doppler velocity and cerebral blood flow changes. Stroke. 1992;23(5):674-9.

27 Esmael A, Flifel ME, Elmarakby F, Belal T. Predictive value of the transcranial doppler and mean arterial flow velocity for early detection of cerebral vasospasm in aneurysmal subarachnoid hemorrhage. Ultrasound. 2021;29(4):218-28.
-2828 Snider SB, Migdady I, LaRose SL, Mckeown ME, Regenhardt RW, Lai PM, et al. Transcranial-doppler-measured vasospasm severity is associated with delayed cerebral infarction after subarachnoid hemorrhage. Neurocrit Care. 2022;36(3):815-21.) All TCD scans were performed under conditions of normocapnia (arterial partial pressure of carbon dioxide - paCO2 between 38 and 42mmHg) by the same two experienced operators (MGH and PG). At least two TCD scans were performed for all patients, the first within days 3 to 7 of evolution and the second between days 8 to 12. In the event of vasospasm, scans were repeated on a daily basis, recording higher velocities in the periods mentioned. In the event of clinical neurodegeneration at any time during evolution, ultrasound scans were repeated.

Neurological impairment due to delayed cerebral ischemia was defined as a change in the level of consciousness (decrease in Glasgow Coma Scale - GCS - by 2 or more points) or development of a new focal deficit with a duration of at least 1 hour, from day 3, exhaustively ruling out other causes such as hydrocephalus, rebleeding, metabolic complications, dysnatremia and systemic complications.(2929 Vergouwen MD, Vermeulen M, Van Gijn J, Rinkel GJ, Wijdicks EF, Muizelaar JP, et al. Definition of delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage as an outcome event in clinical trials and observational studies: proposal of a multidisciplinary research group. Stroke. 2010;41(10):2391-5.) Cerebral infarction or radiological delayed cerebral ischemia was defined as the presence of cerebral infarction on CT or magnetic resonance imaging (MRI) of the brain within 6 weeks after SAH, not present in the first 48 hours after occlusion of the aneurysm and not attributable to other causes, such as surgical clipping or endovascular treatment. Hypodensities on CT resulting from external ventricular shunt (EVS) placement or the evacuation of parenchymal hematomas were not considered.(2828 Snider SB, Migdady I, LaRose SL, Mckeown ME, Regenhardt RW, Lai PM, et al. Transcranial-doppler-measured vasospasm severity is associated with delayed cerebral infarction after subarachnoid hemorrhage. Neurocrit Care. 2022;36(3):815-21.

29 Vergouwen MD, Vermeulen M, Van Gijn J, Rinkel GJ, Wijdicks EF, Muizelaar JP, et al. Definition of delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage as an outcome event in clinical trials and observational studies: proposal of a multidisciplinary research group. Stroke. 2010;41(10):2391-5.
-3030 Rabinstein AA, Weigand S, Atkinson JL, Wijdicks EF. Patterns of cerebral infarction in aneurysmal subarachnoid hemorrhage. Stroke. 2005;36(5):992-7.)

Statistical analysis

Nominal variables are presented as absolute frequencies or percentages, and continuous variables are presented as medians with interquartile ranges because most data did not present a normal distribution. The comparison of nominal variables was carried out using the chi-square or Fisher test, as appropriate, and continuous variables were compared using the Mann‒Whitney U test. Different tomographic scores were compared based on the development of vasospasm. In this sense, sensitivity, specificity, and positive and negative predictive values were determined, and ROC curves were used to determine the area under the curve. The analysis of factors associated with the GOS was performed by univariate analysis. The significant variables and those clinically relevant were included in a multivariate model after logistic regression. Variables with collinearity were excluded from the model, retaining only one based on clinical relevance. Finally, neurological evolution was evaluated using Kaplan‒Meier survival curves, and the groups were compared using the log rank test. In all cases, p<0.05 was considered significant. SPSS version 21.0 was used for the statistical analyses.

RESULTS

In the study period, 77 patients were admitted with a diagnosis of aneurysmal SAH, of whom 20 were excluded (12 due to death in the first 72 hours, 7 due to a poor sonographic window and 1 due to loss to follow-up). The demographic and clinical characteristics of the 57 patients studied are shown in table 2. Sixty-five percent of the patients underwent surgical clipping of the aneurysm, and 28% underwent endovascular treatment of the aneurysm.

Table 2
Demographic and clinical characteristics of the population

Digital arteriography was performed in 22 patients. This procedure was implemented 2.5 days (1 - 6) after admission. Arteriographic vasospasm was defined as a thinning of the contrast medium column in the major cerebral arteries.(3131 Ecker A, Riemenschneider PA. Arteriographic demonstration of spasm of the intracranial arteries, with special reference to saccular arterial aneurysms. J Neurosurg. 1951;8(6):660-7.) No significant correlation was found between arteriographic and sonographic vasospasm (Pearson’s correlation: 0.462, p = 0.03) or between arteriographic and radiological cerebral ischemia.

Sixty percent of the patients developed TCD vasospasm. The variables associated with the development of vasospasm are shown in Table 3. Figure 1 shows the correlation between the different tomographic scales and the development of cerebral vasospasm. The Claassen and Hijdra scales were significantly associated with this complication (p = 0.001 and p = 0.022, respectively). Figure 2 shows the ROC curves for the correlations between the tomographic scales and the development of sonographic vasospasm, with the Claassen score showing the greatest area under the curve (0.78), followed by the Hijdra score (0.68) and Fisher’s score (0.62). Category 4 in the Claassen scale showed the highest positive (88%) and negative (63%) predictive value for the development of cerebral vasospasm.

Table 3
Factors associated with the development of cerebral vasospasm

Figure 1
Correlation between tomographic scales and the development of cerebral vasospasm.

Figure 2
ROC curve showing the correlation between tomographic scales and the development of sonographic vasospasm.

Regarding the severity of cerebral vasospasm, 5 patients (15%) developed severe vasospasm, 12 (35%) developed moderate vasospasm, and 17 (50%) developed mild vasospasm. Figure 3 shows the correlation of the tomographic scales with vasospasm severity. A score of 4 in the Claassen tomographic classification was significantly associated with the development of moderate or severe vasospasm (p = 0.006).

Figure 3
The correlation of the Fisher and Claassen tomographic scales with vasospasm severity.

Forty-four patients (81%) were clinically evaluated for neurological deterioration due to delayed ischemia; 25 (57%) were positive for such deterioration. Thirty-two patients (56.1%) presented CT cerebral infarction. The factors that were statistically significantly associated with this presentation were poor clinical grade at admission (p = 0.04), intracranial hypertension (p = 0.013), sonographic vasospasm (p = 0.008), and vasospasm severity (p = 0.015) (Table 4). In 24 (75%) of these patients, sonographic vasospasm was detected, and in those who did not present infarction on CT, sonographic vasospasm occurred in 40%. The maximum mean velocity on TCD for the patients who developed CT infarction was significantly higher than that in those who did not present tomographic infarction: 138 (103 - 158) cm/sec versus 84 (66 - 118) cm/sec, respectively; the same occurred with the maximum Lindegaard index value for both groups: 3.6 (2.7 - 4.4) versus 2.2 (1.85 - 2.8), respectively. The Fisher and Claassen tomographic scales were not significantly correlated with the development of radiological delayed cerebral ischemia, unlike the Hijdra scale, which was significantly associated with the aforementioned cerebral ischemia (p = 0.009). The patients who presented cerebral infarction had a worse neurological evolution and higher mortality (p < 0.001 and p = 0.001, respectively).

Table 4
Factors associated with the development of cerebral infarction or radiological delayed cerebral ischemia

Forty patients (70%) had a poor neurological outcome, defined by a GOS of 1 to 3. The causes of death were 77% neurological and 23% nonneurological. Factors associated with poor outcomes were greater clinical severity upon admission (defined by a higher SAPS 3 score and Hunt and Hess and WFNS classifications), intracranial hypertension, a higher score on the 3 tomographic scales and CT cerebral infarction. The multivariate analysis of the factors that did not present collinearity showed that CT cerebral infarction was the only factor that was independently associated with poor neurological evolution (odds ratio - OR 8.2; 95% confidence interval - 95%CI 1.043-64.83) (Table 5). Figure 4 shows the survival curves for patients with and without CT cerebral infarction (log rank p = 0.012).

Table 5
Factors associated with poor neurological evolution (Glasgow Outcome Score 1 to 3). Multivariate analysis

Figure 4
Kaplan-Meier survival curves for patients with and without cerebral infarction on computed tomography (log rank p = 0.012).

DISCUSSION

The association between the amount and topography of the blood in SAH with the development of cerebral vasospasm and delayed ischemia has been described in multiple clinical studies.(1515 van der Steen WE, Leemans EL, van den Berg R, Roos YB, Marquering HA, Verbaan D, et al. Radiological scales predicting delayed cerebral ischemia in subarachnoid hemorrhage: systematic review and meta-analysis. Neuroradiology. 2019;61(3):247-56.,1818 Friedman JA, Goerss SJ, Meyer FB, Piepgras DG, Pichelmann MA, McIver JI, et al. Volumetric quantification of Fisher grade 3 aneurysmal subarachnoid hemorrhage: a novel method to predict symptomatic vasospasm on admission computerized tomography scans. J Neurosurg. 2002;97(2):401-7.,3232 Reilly C, Amidei C, Tolentino J, Jahromi BS, Macdonald RL. Clot volume and clearance rate as independent predictors of vasospasm after aneurysmal subarachnoid hemorrhage. J Neurosurg. 2004;101(2):255-61.) In this sense, over the years and from the scale originally described by Fisher et al., several tomographic scores have been designed to predict the development of these complications.(1111 Fisher CM, Kistler JP, Davis JM. Relation of cerebral vasospasm to subarachnoid hemorrhage visualized by computerized tomographic scanning. Neurosurgery. 1980;6(1):1-9.,2020 Claassen J, Bernardini GL, Kreiter K, Bates J, Du YE, Copeland D, et al. Effect of cisternal and ventricular blood on risk of delayed cerebral ischemia after subarachnoid hemorrhage: the Fisher scale revisited. Stroke. 2001;32(9):2012-20.,2121 Hijdra A, Brouwers PJ, Vermeulen M, van Gijn J. Grading the amount of blood on computed tomograms after subarachnoid hemorrhage. Stroke. 1990;21(8):1156-61.,3232 Reilly C, Amidei C, Tolentino J, Jahromi BS, Macdonald RL. Clot volume and clearance rate as independent predictors of vasospasm after aneurysmal subarachnoid hemorrhage. J Neurosurg. 2004;101(2):255-61.) However, there are discrepancies between the different variables used to quantify these complications as well as the diagnostic accuracy of these scales to predict the complications.(99 Frontera JA, Fernandez A, Schmidt M, Claassen J, Wartenberg KE, Badjatia N, et al. Defining vasospasm after subarachnoid hemorrhage: what is the most clinically relevant definition? Stroke. 2009;40(6):1963-8.,1212 Smith ML, Abrahams JM, Chandela S, Smith MJ, Hurst RW, Le Roux PD. Subarachnoid hemorrhage on computed tomography scanning and the development of cerebral vasospasm: the Fisher grade revisited. Surg Neurol. 2005;63(3):229-34; discussion 234-5.,3333 Hijdra A, van Gijn J, Nagelkerke NJ, Vermeulen M, van Crevel H. Prediction of delayed cerebral ischemia, rebleeding, and outcome after aneurysmal subarachnoid hemorrhage. Stroke. 1998;19(10):1250-6.

34 Klimo P Jr, Schmidt RH. Computed tomography grading schemes used to predict cerebral vasospasm after aneurysmal subarachnoid hemorrhage: a historical review. Neurosurg Focus. 2006;21(3):E5.

35 Kramer AH, Hehir M, Nathan B, Gress D, Dumont AS, Kassell NF, et al. A comparison of 3 radiographic scales for the prediction of delayed ischemia and prognosis following subarachnoid hemorrhage. J Neurosurg. 2008;109(2):199-207.
-3636 Lindvall P, Runnerstam M, Birgander R, Koskinen LO. The Fisher grading correlated to outcome in patients with subarachnoid haemorrhage. Br J Neurosurg. 2009;23(2):188-92.)

This is the first study on the subject in our environment. TCD is routinely used in neurocritical patients as a diagnostic screening tool to identify vasospasm of larger cerebral arteries, with good accuracy compared to digital arteriography, which is the gold standard.(3737 Aaslid R, Markwalder TM, Nornes H. Noninvasive transcranial doppler ultrasound recording of flow velocity in basal cerebral arteries. J Neurosurg. 1982;57(6):769-74.

38 Kumar G, Shahripour RB, Harrigan MR. Vasospasm on transcranial doppler is predictive of delayed cerebral ischemia in aneurysmal subarachnoid hemorrhage: a systematic review and meta-analysis. J Neurosurg. 2016;124(5):1257-64.

39 Sloan MA, Haley EC Jr, Kassell NF, Henry ML, Stewart SR, Beskin RR, et al. Sensitivity and specificity of transcranial doppler ultrasonography in the diagnosis of vasospasm following subarachnoid hemorrhage. Neurology. 1989;39(11):1514-8

40 Naqvi J, Yap KH, Ahmad G, Ghosh J. Transcranial doppler ultrasound: a review of the physical principles and major applications in critical care. Int J Vasc Med. 2013;2013:629378.
-4141 Alexandrov AV, Sloan MA, Wong LK, Douville C, Razumovsky AY, Koroshetz WJ, Kaps M, Tegeler CH; American Society of Neuroimaging Practice Guidelines Committee. Practice standards for transcranial Doppler ultrasound: part I - test performance. J Neuroimaging. 2007;17(1):11-8.) The incidence of sonographic vasospasm in our population was 60%, a finding that is consistent with the results reported for different series.(99 Frontera JA, Fernandez A, Schmidt M, Claassen J, Wartenberg KE, Badjatia N, et al. Defining vasospasm after subarachnoid hemorrhage: what is the most clinically relevant definition? Stroke. 2009;40(6):1963-8..4242 Vergouwen MD, Ilodigwe D, Macdonald RL. Cerebral infarction after subarachnoid hemorrhage contributes to poor outcome by vasospasm dependent and -independent effects. Stroke. 2011;42(4):924-9.

43 Seiler RW, Grolimund P, Aaslid R, Huber P, Nornes H. Cerebral vasospasm evaluated by transcranial ultrasound correlated with clinical grade and CT-visualized subarachnoid hemorrhage. J Neurosur. 1986;64(4):594-600.
-4444 Carrera E, Schmidt JM, Oddo M, Fernandez L, Claassen J, Seder D, et al. Transcranial Doppler for predicting delayed cerebral ischemia after subarachnoid hemorrhage. Neurosurgery. 2009;65(2):316-23; discussion 323-4.) Delayed cerebral ischemia and evolution in the ICU were the only variables that were significantly associated with vasospasm, reaffirming the concept indicated by other authors that sonographic detection could be implemented as a tool for the clinical detection of neurodeterioration.(2828 Snider SB, Migdady I, LaRose SL, Mckeown ME, Regenhardt RW, Lai PM, et al. Transcranial-doppler-measured vasospasm severity is associated with delayed cerebral infarction after subarachnoid hemorrhage. Neurocrit Care. 2022;36(3):815-21.,4545 Naval NS, Thomas CE, Urrutia VC. Relative changes in flow velocities in vasospasm after subarachnoid hemorrhage: a transcranial Doppler study. Neurocrit Care. 2005;2(2):133-40.)

In our study population, the Claassen and Hijdra tomographic scales showed the best correlation with the development of sonographic vasospasm. Consistent with the results reported by Frontera et al., the original Fisher scale, which has been widely used as a prognostic tool, presents weaknesses mainly in cases with a thick layer of subarachnoid blood associated with parenchymal or intraventricular hemorrhage. This has generated confusion in the tomographic staging of patients with SAH, also showing little statistical correlation with the development of cerebral vasospasm in relation to the other scales analyzed.(1313 Frontera JA, Claassen J, Schmidt JM, Wartenberg KE, Temes R, Connolly ES Jr, et al. Prediction of symptomatic vasospasm after subarachnoid hemorrhage: the modified fisher scale. Neurosurgery. 2006;59(1):21-7; discussion 21-7.)

Fifty-six percent of the patients in our series developed radiological delayed cerebral ischemia, a percentage that is somewhat higher than that reported in the literature.(1515 van der Steen WE, Leemans EL, van den Berg R, Roos YB, Marquering HA, Verbaan D, et al. Radiological scales predicting delayed cerebral ischemia in subarachnoid hemorrhage: systematic review and meta-analysis. Neuroradiology. 2019;61(3):247-56.) Although neurological deterioration due to delayed ischemia is a variable associated with poor neurological evolution in SAH, it is difficult to define objectively. For this reason, in our study, radiological delayed ischemia or cerebral infarction on CT was considered, which represents a part of all these patients but surely includes a subgroup with greater severity.(2828 Snider SB, Migdady I, LaRose SL, Mckeown ME, Regenhardt RW, Lai PM, et al. Transcranial-doppler-measured vasospasm severity is associated with delayed cerebral infarction after subarachnoid hemorrhage. Neurocrit Care. 2022;36(3):815-21.,3030 Rabinstein AA, Weigand S, Atkinson JL, Wijdicks EF. Patterns of cerebral infarction in aneurysmal subarachnoid hemorrhage. Stroke. 2005;36(5):992-7.) Consistent with the results reported for other series, delayed cerebral ischemia was statistically significantly associated with clinical severity upon admission, cerebral vasospasm and vasospasm severity. In 25% of the patients who developed tomographic cerebral infarction, sonographic vasospasm was not detected, a finding that could be due to the existence of other pathogenic factors associated with the development of delayed cerebral ischemia, as has been shown in several clinical studies, such as cortical spreading depression, microthrombosis, neuroinflammation and hypoperfusion due to increased intracranial pressure (ICP).(1515 van der Steen WE, Leemans EL, van den Berg R, Roos YB, Marquering HA, Verbaan D, et al. Radiological scales predicting delayed cerebral ischemia in subarachnoid hemorrhage: systematic review and meta-analysis. Neuroradiology. 2019;61(3):247-56.,4646 Macdonald RL, Higashida RT, Keller E, Mayer SA, Molyneux A, Raabe A, et al. Randomised trial of clazosentan, an endothelin receptor antagonist, in patients with aneurysmal subarachnoid hemorrhage undergoing surgical clipping (CONSCIOUS-2). Acta Neurochir Suppl. 2013;115:27-31.) Regarding this last factor, although ICP was only monitored in 64.9% of the patients in our series, the presence of intracranial hypertension was significantly associated with the development of cerebral infarction, indicating the possible contribution of cerebral hypoperfusion due to elevated ICP to cerebral ischemia in our patients. Another factor that could also explain this difference is the fact that TCD has very good specificity but moderate sensitivity; therefore, there could be cases of undetected cerebral vasospasm that could affect the development of delayed cerebral ischemia in our population.

In our study, the Fisher and Claassen scales were not significantly correlated with the development of cerebral infarction, unlike the Hijdra tomographic scale. One factor that could explain this is that the Fisher and Claassen scales are qualitative, which is why they have been criticized by different authors due to their lack of reliability linked to sometimes confusing classification criteria.(4747 Jiménez-Roldán L, Alén JF, Gómez PA, Lobato RD, Ramos A, Munarriz PM, et al. Volumetric analysis of subarachnoid hemorrhage: assessment of the reliability of two computerized methods and their comparison with other radiographic scales. J Neurosurg. 2013;118(1):84-93.) The semiquantitative Hijdra scale allows a more objective assessment of blood volume, with a better prognostic accuracy, which could also explain why in our population the Hijdra scale score, not qualitative scale scores, was significantly associated with radiological cerebral ischemia. Importantly, the measurement of the amount of blood using these 3 scales continues to depend on the observer; therefore, the quantification of the real blood volume on CT using computer programs is the ideal reference method.(4747 Jiménez-Roldán L, Alén JF, Gómez PA, Lobato RD, Ramos A, Munarriz PM, et al. Volumetric analysis of subarachnoid hemorrhage: assessment of the reliability of two computerized methods and their comparison with other radiographic scales. J Neurosurg. 2013;118(1):84-93.,4848 Street JS, Pandit AS, Toma AK. Predicting vasospasm risk using first presentation aneurysmal subarachnoid hemorrhage volume: a semi-automated CT image segmentation analysis using ITK-SNAP. PLoS One. 2023;18(6):e0286485.)

The neurological outcome of our patients reflects the severity of this disease, with 70% of the patients who were discharged from the ICU having a GOS of 1 to 3. Cerebral infarction on CT was the only independent factor associated with severity, with a relative risk of more than 8 times of presenting poor evolution.

This study has several limitations. First, this was a single-center study with a relatively small number of patients, although it was relevant to our environment. Second, the diagnosis of vasospasm was made by TCD because systematic digital arteriography, which is the reference method is not performed in our unit. Third, because the initial CT scan was analyzed to determine scale scores, blood clearance was not taken into account in the evolution, which has been shown to be a positive prognostic factor.(4949 Reilly C, Amidei C, Tolentino J, Jahromi BS, Macdonald RL. Clot volume and clearance rate as independent predictors of vasospasm after aneurysmal subarachnoid hemorrhage. J Neurosurg. 2004;101(2):255-61.) Fourth, TCD was followed up until day 12 of evolution, which includes the period of time with the highest incidence of vasospasm, with reports of development until day 21, thus potentially resulting in underdiagnosis.(2828 Snider SB, Migdady I, LaRose SL, Mckeown ME, Regenhardt RW, Lai PM, et al. Transcranial-doppler-measured vasospasm severity is associated with delayed cerebral infarction after subarachnoid hemorrhage. Neurocrit Care. 2022;36(3):815-21.,5050 Jarus-Dziedzic K, Juniewicz H, Wroñski J, Zub WL, Kasper E, Gowacki M, et al. The relation between cerebral blood flow velocities as measured by TCD and the incidence of delayed ischemic deficits. A prospective study after subarachnoid hemorrhage. Neurol Res. 2002;24(6):582-92.) Fifth, given that in our institution we do not have CT with perfusion, the incidence of delayed cerebral ischemia may be underestimated.(5151 Starnoni D, Maduri R, Hajdu SD, Pierzchala K, Giammattei L, Rocca A, et al. Early perfusion computed tomography scan for prediction of vasospasm and delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage. World Neurosurg. 2019;130:e743-52.) Sixth, 19% of the patients could not be clinically evaluated for neurological deterioration due to their initial severity and/or need for sedation. Finally, the evolution of the patients was followed until discharge from the hospital and not at 6 months, as is recommended for such patients.

CONCLUSION

This is the first study on this subject in our environment. Our findings indicate that the Claassen and Hijdra tomographic scales show better performance and could be useful prognostic tools for cerebral vasospasm development. Likewise, the finding of sonographic vasospasm can serve as a noninvasive criterion for the early detection of delayed cerebral ischemia and neurological deterioration in patients with subarachnoid hemorrhage. In our population, only the semiquantitative Hijdra scale was correlated with cerebral infarction on computed tomography. Studies with a larger number of patients are needed to confirm these results.

  • Responsible editor: Viviane Cordeiro Veiga

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Publication Dates

  • Publication in this collection
    22 Dec 2023
  • Date of issue
    2023

History

  • Received
    12 May 2023
  • Accepted
    07 Sept 2023
Associação de Medicina Intensiva Brasileira - AMIB Rua Arminda, 93 - 7º andar - Vila Olímpia, CEP: 04545-100, Tel.: +55 (11) 5089-2642 - São Paulo - SP - Brazil
E-mail: ccs@amib.org.br