Automated Grading of Cerebral Vasospasm to Standardize Computed Tomography Angiography Examinations After Subarachnoid Hemorrhage

Impact of pre-hospital handling and initial time to cranial computed tomography on outcome in aneurysmal subarachnoid hemorrhage patients with out-of-hospital sudden cardiac arrest-a retrospective bi-centric study

Background

Aneurysmal subarachnoid hemorrhage (SAH) presents occasionally with cardiac arrest (CA). The impact of pre-hospital and emergency room (ER) treatment on outcome remains unclear. Therefore, we investigated the impact of pre-hospital treatment, focusing on lay cardiopulmonary resuscitation (CPR), and ER handling on the outcome of SAH patients with out-of-hospital CA (OHCA).

Methods

In this bi-centric retrospective analysis, we reviewed SAH databases for OHCA and CPR from January 2011 to June 2021. Patients were analyzed for general clinical and epidemiological parameters. CPR data were obtained from ambulance reports and information on ER handling from the medical records. Data were correlated with patient survival at hospital discharge as a predefined outcome parameter.

Results

Of 1,120 patients with SAH, 45 (4.0%) were identified with OHCA and CPR, 38 of whom provided all required information and were included in this study. Time to resuscitation was significantly shorter with lay resuscitation (5.3 ± 5.2 min vs. 0.3 ± 1.2 min, p = 0.003). Nineteen patients were not initially scheduled for cranial computed tomography (CCT), resulting in a significantly longer time interval to first CCT (mean ± SD: 154 ± 217 min vs. 40 ± 23 min; p < 0.001). Overall survival to discharge was 31.6%. Pre-hospital lay CPR was not associated with higher survival (p = 0.632). However, we observed a shorter time to first CCT in surviving patients (p = 0.065).

Conclusions

OHCA in SAH patients is not uncommon. Besides high-quality CPR, time to diagnosis of SAH appears to play an important role. We therefore recommend considering CCT diagnostics as part of the diagnostic algorithm in patients with OHCA.

Reference Values of Cerebral Artery Diameters of the Anterior Circulation by Digital Subtraction Angiography: A Retrospective Study

A threshold-based classification of cerebral vasospasm needs reference values for intracranial vessel diameters on digital subtraction angiography (DSA). We aimed to generate adjusted reference values for this purpose by retrospectively analyzing angiograms and potential influencing factors on vessel diameters. Angiograms of the anterior circulation were evaluated in 278 patients aged 18−81 years. The vessel diameters of 453 angiograms (175 bilateral) were gathered from nine defined measuring sites. The effect sizes of physical characteristics (i.e., body weight and height, body mass index, gender, age, and cranial side) and anatomical variations were calculated with MANOVA. Segments bearing aneurysms were excluded for the calculation of reference values. Adjusted vessel diameters were calculated via linear regression analysis of the vessel diameter data. Vessel diameters increased with age and body height. Male and right-sided vessels were larger in diameter. Of the anatomical variations, only the hypoplastic/aplastic A1 segment had a significant influence (p < 0.05) on values of the anterior cerebral artery and the internal carotid artery with a small effect size (|ω2| > 0.01) being excluded from the reference values. We provide gender-, age-, and side-adjusted reference values and nomograms of arterial vessel diameters in the anterior circulation.

Temporal averaging angiographic reconstructions from whole-brain CT perfusion for the detection of vasospasm

PURPOSE

The aim of this study is to evaluate the image quality and diagnostic performance of angiographic images reconstructed from whole-brain CT perfusion (CTP) using temporal averaging compared to CT angiography (CTA) for the detection of vasospasm.

MATERIALS AND METHODS

39 CT studies in 28 consecutive patients who underwent brain CTA with CTP for suspected vasospasm between September 2020 and May 2021 were retrospectively evaluated. The image quality of these two vascular imaging techniques was assessed either quantitatively (image noise, vascular enhancement, signal-to-noise (SNR) and contrast-to-noise (CNR) ratios,) and qualitatively (4 criteria assessed on a 5-point scale). Intra and interobserver agreements and a diagnostic confidence score on the diagnosis of vasospasm were measured. Radiation dose parameters (volume CT dose index (CTDI_vol) and dose-length product (DLP)) were recorded.

RESULTS

Both SNR and CNR were significantly higher with temporal averaging compared to CTA, increasing by 104% and 113%, respectively (p<0.001). The qualitative assessment found no significant difference in overall image quality between temporal averaging (4.33 ± 0.48) and brain CTA (4.19 ± 0.52) (p = 0.12).There was a significant improvement in intravascular noise and arterial contrast enhancement with temporal averaging. The evaluation of intra and interobserver agreements showed a robust concordance in the diagnosis of vasospasm between the two techniques.

CONCLUSIONS

Temporal averaging appeared as a feasible and reliable imaging technique for the detection of vasospasm. The use of temporal averaging, replacing brain CTA, could represent a new strategy of radiation and contrast material doses reduction in these patients.

Sensorineural hearing loss due to delayed cerebral ischemia in bilateral auditory cortices following aneurysmal subarachnoid hemorrhage: illustrative case

BACKGROUND

Recognizing rare signs of delayed cerebral ischemia (DCI) is crucial to caring for patients with subarachnoid hemorrhage. The authors presented a case of central hearing loss that occurred during the clinical course of a patient treated for aneurysmal subarachnoid hemorrhage.

OBSERVATIONS

The patient had a ruptured right posterior communicating artery aneurysm successfully treated with coil embolization but later developed severe vasospasm and DCI. She developed bilateral hearing loss, and imaging revealed DCI to the left temporal lobe and the right auditory cortex. Computed tomography angiography and digital subtraction angiography demonstrated severe vasospasm of bilateral internal carotid arteries, bilateral middle cerebral arteries, and bilateral anterior cerebral arteries. One month after hospitalization, the patient had recovered fully neurologically intact except for persistent hearing loss.

LESSONS

This case serves to teach important neuroanatomical features and discuss the unique pathophysiology of DCI affecting the auditory cortex.

Continuous Intraarterial Nimodipine Infusion for the Treatment of Delayed Cerebral Ischemia After Aneurysmal Subarachnoid Hemorrhage: A Retrospective, Single-Center Cohort Trial

Background

Delayed cerebral ischemia (DCI) occurs after aneurysmal subarachnoid hemorrhage (aSAH). Continuous intraarterial nimodipine infusion (CIAN) is a promising approach in patients with intracranial large vessel vasospasm (LVV). The objective of this retrospective single-center cohort study was to evaluate the outcome in aSAH-patients treated with CIAN.

Methods

CIAN was initiated and ended based on the clinical evaluation and transcranial Doppler (TCD), CT-angiography, CT-perfusion (PCT), and digital subtraction angiography (DSA). Nimodipine (0.5–2.0 mg/h) was administered continuously through microcatheters placed in the extracranial internal carotid and/or vertebral artery. Primary outcome measures were Glasgow Outcome Scale (GOS) at discharge and within 1 year after aSAH, and the occurrence of minor and major (<⅓ and >⅓ of LVV-affected territory) DCI-related infarctions in subsequent CT/MRI-scans. Secondary outcome measures were CIAN-associated complications.

Results

A total of 17 patients underwent CIAN. Median onset of CIAN was 9 (3–13) days after aSAH, median duration was 5 (1–13) days. A favorable outcome (GOS 4–5) was achieved in 9 patients (53%) at discharge and in 13 patients within 1 year (76%). One patient died of posthemorrhagic cerebral edema. Minor cerebral infarctions occurred in five and major infarctions in three patients. One patient developed cerebral edema possibly due to CIAN. Normalization of PCT-parameters within 2 days was observed in 9/17 patients. Six patients showed clinical response and thus did not require PCT imaging.

Conclusion

The favorable outcome in 76% of patients after 1 year is in line with previous studies. CIAN thus may be used to treat patients with severe therapy-refractory DCI.

Computed tomography angiography for quantification of cerebral vasospasm following aneurysmal subarachnoid hemorrhage

PURPOSE

The purpose of this study was to assess the accuracy of computed tomography angiography (CTA) for quantification of cerebral vasospasm following aneurysmal subarachnoid hemorrhage in proximal and middle segments of intracranial arteries.

MATERIALS AND METHODS

Twenty consecutive patients (7 men, 13 women; mean age, 47 ± 7 [SD] years; age range: 27-78 years) with aneurysmal subarachnoid hemorrhage who underwent CTA and digital subtracted angiography (DSA) with a 6-hour window at baseline and during vasospasm period were included. Twelve artery segments were analyzed in each patient. Vasospasm was blindly quantified on CTA and digital subtracted angiography (DSA) by two independent readers with discordance > 10% resolved by open data consensus. Inter-reader and inter-test correlations with DSA as reference, and causes of discordant readings were analyzed. The best sensitivity and specificity of CTA for determination of vasospasm ≥ 50% on DSA was determined using receiver operating curve analysis.

RESULTS

Two-hundred-and-ten arterial segments were analyzed after exclusion of 30 segments with missing data or metallic artifacts. An inter-reader discordance >10% was observed in 82 segments (82/210; 39% [95% CI: 32-46]). Inter-test discordances >10% were observed respectively in 115 segments (115/210; 55% [95% CI: 49-62]) with the junior reader and in 73 segments (73/210; 35% [95% CI: 29-42]) with the senior reader. They were related to reader error in 55 (55/210; 26% [95% CI: 20-32]) with the junior reader and 13 (13/210; 6% [95% CI: 3-9]) with the senior reader, as well systematic biases in 8 (8/210; 4% [95% CI: 1-6]), and intrinsic limitation in 52 (52/210; 25% [95% CI: 19-31]). Best sensitivity and specificity of CTA were observed for a threshold value of 30% (sensitivity = 88% [95% CI: 78-97%]; specificity = 84% [95% CI: 77-90%]; area under curve = 0.92 [95% CI: 0.86-0.97]). On a patient basis, sensitivity was 100% (specificity = 60% [95% CI: 38-81%]; area under curve = 0.97 [95% CI: 89-100%] for this same threshold.

CONCLUSION

Our study shows a moderate accuracy of CTA for the quantification of cerebral vasospasm, mostly related to challenging interpretation and intrinsic limitations. CTA may rule-out angiographic vasospasm ≥ 50% when no segment has vasospasm over than 30%.

Diagnostic accuracy of shuttle CT angiography (CTA) and helical CTA in the diagnosis of vasospasm

PURPOSE

To evaluate the diagnostic accuracy of computed tomography angiography (CTA) acquired with shuttle technique (CTAs) and helical CTA (CTAh) for vasospasm, using digital subtraction angiography (DSA) obtained within 24 h as reference standard.

METHODS

Thirty-six patients with suspected vasospasm in the setting of aneurysmal subarachnoid hemorrhage (ASAH, 30/36) or acute inflammatory/infectious conditions (6/36) who underwent CTAs (17/36) or CTAh (19/36) followed by DSA within 24 h were identified retrospectively. Presence of vasospasm in the proximal cerebral arterial segments was assessed qualitatively and semi-quantitatively on CTA and subsequent DSA. Sensitivity, specificity, and receiver operating characteristic (ROC) curves were calculated. Inter-rater variability was assessed using Cohen's kappa.

RESULTS

On CTAs, 35% of patients had low and 65% had high vasospasm burden. On CTAh, 37% had low and 63% had high vasospasm burden. ROC analysis demonstrated an AUC of 0.87 for CTAs (95%CI 0.67-1.00, p = 0.015) and 0.88 for CTAh (0.72-1.00, p = 0.028). Cohen's kappa was 0.843 (95%CI 0.548-1.000). Thresholding with Youden's J index, CTAs had a sensitivity of 85.71% (95%CI 48.69 to 99.27) and specificity of 66.67% (35.42 to 87.94). CTAh had sensitivity of 100% (56.55 to 100.00) and specificity of 78.57% (52.41 to 92.43).

CONCLUSION

CTAs and CTAh yielded similar sensitivity, specificity, and AUC values on ROC analysis for the detection of vasospasm using DSA as reference standard. Our findings suggest that CTAs is a promising alternative to CTAh especially in patients requiring serial imaging, given its potential advantages of decreased radiation exposure, contrast dose, and cost-effectiveness.

Length of hospital stay in aneurysmal subarachnoid hemorrhage patients without vasospasm on angiography: potential for a fast-track discharge cohort

BACKGROUND

Patients with aneurysmal subarachnoid hemorrhage (aSAH) frequently suffer from vasospasm. We analyzed the association between absence of early angiographic vasospasm and early discharge.

METHODS

All aSAH patients treated from August 1, 2007, to July 31, 2019, at a single tertiary center were reviewed. Patients undergoing diagnostic digital subtraction angiography (DSA) on post-aSAH days 5 to 7 were analyzed; cohorts with and without angiographic vasospasm (angiographic reports by attending neurovascular surgeons) were compared. Primary outcome was hospital length of stay; secondary outcomes were intensive care unit length of stay, 30 day return to the emergency department (ED), and poor neurologic outcome, defined as a modified Rankin Scale (mRS) score >2.

RESULTS

A total of 298 patients underwent DSA on post-aSAH day 5, 6, or 7. Most patients (n=188, 63%) had angiographic vasospasm; 110 patients (37%) did not. Patients without vasospasm had a significantly lower mean length of hospital stay than vasospasm patients (18.0±7.1 days vs 22.4±8.6 days; p<0.001). The two cohorts did not differ significantly in the proportion of patients with mRS scores >2 at last follow-up or those returning to the ED before 30 days. After adjustment for Hunt and Hess scores, Fisher grade, admission Glasgow Coma Scale score, and age, logistic regression analysis showed that the absence of vasospasm on post-aSAH days 5-7 predicted discharge on or before hospital day 14 (OR 3.4, 95% CI 1.8 to 6.4, p<0.001).

CONCLUSION

Lack of angiographic vasospasm 5 to 7 days after aSAH is associated with shorter hospitalization, with no increase in 30 day ED visits or poor neurologic outcome.

Mechanical thrombectomy injury to the arterial wall: A comparison between catheter aspiration and stent retriever

PURPOSE

To compare the extent of arterial wall damage when SR and CA were used for treatment of AIS models to evaluate their efficacy and safety.

METHODS

A thrombin-induced thrombus was pre-injected into the right distal external carotid-maxillary artery (ECMA) in 12 dogs to create an acute thrombus occlusion model and were randomly divided into the SR group (n = 6; received SR treatment) and CA group (n = 6; received CA treatment). Device safety was also assessed by five passages through the normal left ECMA using each device. Device manipulation-related damage to arterial walls, final flow restoration, recanalization time and complications were recorded.

RESULTS

Sixteen retriever and 10 aspiration attempts were performed in the SR and CA groups. Reperfusion time was significantly reduced in the CA group (17.83 ± 1.96 vs. 28.33 ± 3.26 in the SR group; P = 0.02). Stent retriever thrombectomy resulted in an increased risk of endothelium denudation (1.17 ± 0.24 in SR group vs. 0.42 ± 0.15 in CA group; P = 0.01) and reduced frequency of vessel vasospasm (0.67 ± 0.14 in SR group vs. 0.25 ± 0.13 in CA group; P = 0.04). Injury score and thrombus deposition were similar between the two groups (P > 0.05). TICI 2b/3 flow restoration values of the right ECMA were 100 % in both groups. Device-related complications, including dissection (P = 0.21), side branch influence (P = 0.24), and distal thromboembolism (P = 1.00), did not differ between the two groups.

CONCLUSION

Both devices had similar efficacy and caused minimal arterial wall damage in our dog models. SR was more likely to cause endothelium denudation, while CA had a greater risk of vasospasm.

Comparison of Unruptured Intracranial Aneurysm Treatment Score and PHASES Score in Subarachnoid Hemorrhage Patients With Multiple Intracranial Aneurysms

Objective: Unruptured Intracranial Aneurysm (UIA) Treatment Score (UIATS) and PHASES score are used to inform treatment decision making for UIAs (treatment or observation). We assessed the ability of the scoring systems to discriminate between ruptured aneurysms and UIAs in a subarachnoid hemorrhage (SAH) cohort with multiple aneurysms. Methods: We retrospectively applied PHASES and UIATS scoring to the aneurysms of 40 consecutive patients with SAH and multiple intracranial aneurysms. Results: PHASES score discriminated better between ruptured aneurysms and UIAs than UIATS. PHASES scores and the difference between the UIATS subscores were higher for ruptured aneurysms compared with UIAs, which reached significance for the PHASES score. PHASES score estimated a low 5-year rupture risk in a larger proportion of the UIAs (≤0.7% in 62.3%, ≤1.7% in 98.4%) than of the ruptured aneurysms (≤0.7% in 22.5%, ≤1.7% in 82.5%). In the 40 ruptured aneurysms, UIATS provided recommendation for treatment in 11 (27.5%), conservative management in 14 (35.0%), and was inconclusive in 15 cases (37.5%). In the 61 UIAs, UIATS recommended treatment in 16 (26.2%), conservative management in 29 (47.5%), and was inconclusive in 16 (26.2%) cases. Conclusion: Similar to previous SAH cohorts, a significant proportion of the ruptured aneurysms exhibited a low-rupture risk. Nevertheless, PHASES score discriminated between ruptured aneurysms and UIAs in our cohort; the lower discriminatory power of UIATS was due to high weights of aneurysm-independent factors. We recommend careful integration of the scores for individual decision making. Large-scale prospective trials are required to establish score-based treatment strategies for UIAs.