Death by nondiagnosis: why emergent CT angiography should not be done for patients with subarachnoid hemorrhage

Delayed diagnosis of intracranial aneurysm in pediatrics: the risk of misdiagnosis-a case report

BACKGROUND

Aneurysms in the pediatric population are uncommon, requiring a high index of suspicion for diagnosis. We report a case of a child with head trauma and delayed diagnosed cerebral aneurysm.

METHODS

A 2-year-old girl was brought to the emergency room with seizures. Head imaging showed acute intraventricular hemorrhage, hydrocephalus, and paraclinoid aneurysm of the right internal carotid artery. She had been hospitalized elsewhere 1 month prior for traumatic brain injury after falling to the ground with subarachnoid and intraventricular hemorrhage and good recovery, but without diagnosis of aneurysm.

RESULTS

The child was treated with aneurysm embolization and ventriculoperitoneal shunt, being discharged asymptomatic.

CONCLUSION

Most primary intraventricular hemorrhage in pediatric population has identifiable etiology. A high rate of clinical suspicion, associated with a low threshold for vascular neuroimaging studies for children with spontaneous or atypical intracranial hemorrhage allow accurate diagnosis, appropriate treatment, and improved outcome.

Computed Tomography Angiography versus Digital Subtraction Angiography as a Primary Diagnostic Tool in Nontraumatic Subarachnoid Hemorrhage: Cost-Effectiveness Analysis Study

BACKGROUND

Digital subtraction angiography (DSA) and computed tomographic angiography (CTA) are used to identify the cause of nontraumatic subarachnoid hemorrhage (SAH). There is no consensus on which to choose as the first diagnostic tool. We aimed to compare the cost-effectiveness of CTA versus DSA as a primary tool for identifying the cause of nontraumatic SAH.

METHODS

A decision analysis model was built to simulate patients undergoing DSA or CTA as a primary diagnostic tool for the cause of nontraumatic SAH. The input data for the study were extracted from literature. Probabilistic and deterministic sensitivity analyses were performed to evaluate the robustness of the model.

RESULTS

In the base case calculation, it cost $1261.82 less and yielded 0.0001 quality-adjusted life year (QALY) when DSA was used as a primary diagnostic imaging tool for nontraumatic SAH. Choosing DSA as a primary tool was cost-effective in more than 65% of iterations in probabilistic sensitivity analysis. Deterministic sensitivity analyses show when the probability of using endovascular treatment is >47.2%, choosing DSA is more cost-effective; otherwise, CTA is more optimal. CTA is more cost-effective when the cost for DSA >2.6 × CTA + $600.

CONCLUSIONS

Based on current literature and our model DSA as a primary diagnostic tool for the cause of nontraumatic SAH is more cost-effective. However, in clinical practice physicians can choose either DSA or CTA according to the scale of endovascular procedures used in their center, as well as the cost correlation between CTA and DSA, which varies among institutions.

Aneurysmal Subarachnoid Hemorrhage

Aneurysmal subarachnoid hemorrhage is a neurologic emergency that requires immediate patient stabilization and prompt diagnosis and treatment. Early measures should focus on principles of advanced cardiovascular life support. The aneurysm should be evaluated and treated in a comprehensive stroke center by a multidisciplinary team capable of endovascular and, operative approaches. Once the aneurysm is secured, the patient is best managed by a dedicated neurocritical care service to prevent and manage complications, including a syndrome of delayed neurologic decline. The goal of such specialized care is to prevent secondary injury, reduce length of stay, and improve outcomes for survivors of the disease.

Detecting small conflicting drainages with contrast-enhanced magnetic resonance venography for surgical planning: a technical description and quantified analysis

BACKGROUND

Recent studies have shown the challenges involved in detecting small conflicting vessels (1.0-1.5 mm) on contrast-enhanced (CE) T1 images during stereoelectroencephalography (SEEG) planning. Improving the resolution of non-invasive approaches to identify these vessels is possible and important. We present a superior sagittal sinus mapping-based CE-magnetic resonance venography (CE-MRV) protocol calibrated by craniotomies.

METHOD

Seven patients with epileptic symptoms who received craniotomy were enrolled. CE-MRV was acquired with a bolus mapping of the superior sagittal sinus. Together with the T1 image, 3D veins and the brain surface were visualized. The resolution of the CE-MRV was quantified by measuring the diameter of superficial drainages after exposure of the brain surface during craniotomy.

RESULTS

A total of 37 superficial drainages were exposed in the bone windows. CE-MRV visualized all these drainages. On average, one superficial drainage could be found in every 13.2 mm diameter of the bone window. The boundary resolution of the CE-MRV was 0.58-0.8 mm in vessel diameter, while drainages larger than 0.8 mm were visualized consistently.

CONCLUSIONS

The resolution of the CE-MRV in the present study met the requirement for detection of small conflicting vessels during SEEG planning. The visualized venous landmarks could be used for visual guidance to the surgical zone. As a non-invasive approach, CE-MRV is practical to use in the clinical setting.

Digital Subtraction Angiography for CT Angiogram Negative Haemorrhages

BACKGROUND

In patients with subarachnoid haemorrhage (SAH) and a negative finding on CT angiography (CTA), further imaging with digital subtraction angiography (DSA) is commonly performed to identify the source of bleeding. The purpose of this study was to investigate whether negative findings on CTA can reliably exclude aneurysms in patients with acute SAH.

METHODS

This retrospective study identified all DSAs performed between August 2010 and July 2014 within our institution. CT angiography was performed with a 64-section multidetector row CT scanner. Only DSAs from patients with confirmed SAH and a negative CTA result were included in the final analyses. A fellowship-trained neuroradiologist reviewed the imaging results.

RESULTS

Of the 857 DSAs, 50 (5.83%) were performed in 35 patients with CTA-negative SAH. Of the 35 patients, three (8.57%) had positive findings on the DSA. In one patient, suspicious dissection of the extra- and intra-cranial segment of the right vertebral artery could not be confirmed even in retrospect. In the second patient, the suspicious finding of tiny protuberance from the left paraclinoid internal carotid artery (ICA) on DSA did not change on follow-up and did not change patient's management. The third patient had a posterior inferior cerebellar artery aneurysm, which was not seen on the initial CTA owing to the incomplete coverage of the head on the CTA.

CONCLUSION

In patients with SAH, negative findings on a technically sound CTA are reliable in ruling out aneurysms in any pattern of SAH or no blood on CT. Our observations need to be confirmed with larger prospective studies.

Management of aneurysmal subarachnoid hemorrhage: State of the art and future perspectives

Background:

Aneurysmal subarachnoid hemorrhage (SAH) accounts for 5% of strokes and carries a poor prognosis. It affects around 6 cases per 100,000 patient years occurring at a relatively young age.

Methods:

Common risk factors are the same as for stroke, and only in a minority of the cases, genetic factors can be found. The overall mortality ranges from 32% to 67%, with 10–20% of patients with long-term dependence due to brain damage. An explosive headache is the most common reported symptom, although a wide spectrum of clinical disturbances can be the presenting symptoms. Brain computed tomography (CT) allow the diagnosis of SAH. The subsequent CT angiography (CTA) or digital subtraction angiography (DSA) can detect vascular malformations such as aneurysms. Non-aneurysmal SAH is observed in 10% of the cases. In patients surviving the initial aneurysmal bleeding, re-hemorrhage and acute hydrocephalus can affect the prognosis.

Results:

Although occlusion of an aneurysm by surgical clipping or endovascular procedure effectively prevents rebleeding, cerebral vasospasm and the resulting cerebral ischemia occurring after SAH are still responsible for the considerable morbidity and mortality related to such a pathology. A significant amount of experimental and clinical research has been conducted to find ways in preventing these complications without sound results.

Conclusions:

Even though no single pharmacological agent or treatment protocol has been identified, the main therapeutic interventions remain ineffective and limited to the manipulation of systemic blood pressure, alteration of blood volume or viscosity, and control of arterial dioxide tension.

Subarachnoid Hemorrhage after Surgery of the Medulla Oblongata Hemangioblastoma: A Case Report

Objectives

To discuss the bleeding mechanisms after removing a medulla oblongata hemangioblastoma.

Methods

A 42-year-old male patient was diagnosed with a medulla oblongata hemangioblastoma. Preoperative cranial magnetic resonance imaging, computed tomography angiography and post-surgery computed tomography were completed during clinical procedure. We also reviewed the related literatures.

Results

The preoperative computed tomography angiography did not demonstrate any intracranial aneurysm. But, the patient had a fatal subarachnoid hemorrhage with ventricular hemorrhage 4 hours after surgery following the post-surgery computed tomography.

Conclusions

Subarachnoid hemorrhage after surgery of the medulla oblongata hemangioblastoma is very rare. Delayed postoperative hemorrhage seems the most reasonable explanation of Subarachnoid hemorrhage in our case.

Use of the 2.8 French Progreat microcatheter in diagnostic cerebral angiography

BACKGROUND

Tortuous vascular anatomy poses a significant challenge to performing diagnostic cerebral angiography.

OBJECTIVE

To report a new cerebral angiography technique for overcoming tortuous aortic and supra-aortic anatomy using a 2.8 French (F) Progreat microcatheter (0.028 inch (internal diameter) (Terumo; Somerset, New Jersey, USA) to obtain a diagnostic cerebral angiogram.

MATERIALS AND METHODS

A retrospective analysis of consecutive cases undergoing diagnostic cerebral angiography at our institution between 1 January 2013 and 30 November 2015 in which a 2.8F Progreat microcatheter was used. Clinical and operative notes were reviewed and correlated with imaging. Radiologic imaging, including CT, MRI, and digital subtraction angiography, was reviewed. Neurologic, systemic, and local complications were recorded on the basis of clinical follow-up results after each angiographic examination. Events that occurred within 24 h of the angiography were considered to be complications of the procedure.

RESULTS

Initial attempts at catheterization of the target vessel with various 4F and 5F catheters were unsuccessful owing to tortuosity, atherosclerotic disease, or occlusion of the catheter in the target vessel. Microcatheterization of the target vessel was successful in 59/62 (95%) target vessels. A diagnostic cerebral angiogram with a power injection was obtained in 59 (100%) of the successfully catheterized vessels. In one case, angiography proceeded to aneurysm coiling after over-the-wire exchange. In two cases, angiography proceeded to mechanical thrombectomy after over-the-wire exchange. No procedural complications were seen.

CONCLUSIONS

The 2.8F Progreat microcatheter can be used to obtain a diagnostic cerebral angiogram in patients with anatomic challenges limiting catheterization by standard techniques.

Flat Detector Computed Tomography-Based "Dual Vessel Fusion" Technique for Diagnosis and Surgical Planning in the Management of Dural Arteriovenous Fistula

OBJECTIVE

To explore the value of flat detector computed tomography-based vessel fusion technique for visualizing and evaluating anatomic structures and hemodynamic features of patients diagnosed with dural arteriovenous fistulas (DAVF).

METHODS

Eleven patients with DAVF were investigated. The 3-dimensional structure of the DAVF fistula point, feeding arteries, and draining veins were reconstructed from separately acquired rotational angiographic images and then displayed as a single image in a fused manner.

RESULTS

In the vessel fusion image, the tangled cluster of vessels of the DAVF could be clearly visualized from selected optimal viewing angles in the 3-dimensional space. Each component of the DAVF fistula point with its specific artery feedings and venous drainage could be identified accurately.

CONCLUSIONS

The vessel fusion technique gave detailed anatomic information that enabled better understanding of the DAVF structure, and facilitated an accurate interventional or surgical planning.

Endovascular methods for the treatment of intracranial cerebral aneurysms

This article briefly discusses the clinical features, natural history, and epidemiology of intracranial cerebral aneurysms, along with current diagnostic imaging techniques for their detection. The main focus is on the basic techniques used in endovascular coiling of ruptured and nonruptured saccular intracranial cerebral aneurysms. After a discussion of each technique, a short review of the results of each form of treatment is given, concentrating on reported large case series. Specific complications related to the endovascular treatment of saccular intracranial aneurysms are then discussed.

Benefit of a Sharp Computed Tomography Angiography Reconstruction Kernel for Improved Characterization of Intracranial Aneurysms

BACKGROUND:

Computed tomography angiography (CTA) is the first-line imaging modality used for cerebral aneurysms because of its speed and sensitivity for detection, although digital subtraction angiography is often required for more detailed aneurysm shape delineation.

OBJECTIVE:

To determine whether a sharper CTA reconstruction kernel can better characterize an aneurysm and improve decision-making before intervention.

METHODS:

Fifteen patients presenting with aneurysmal subarachnoid hemorrhage underwent 64-row CTA. CTA data were reconstructed using the default H20f smooth kernel and a H60f sharp kernel and compared with contemporaneous catheter 3-dimensional rotational angiography (3DRA). Aneurysm neck, width, and aspect ratio measurements were made using intensity line plots of identical projections on all imaging datasets and compared by matched-pair statistics.

RESULTS:

Aneurysm neck measurements from the H20f smooth kernel revealed overestimation compared with both the sharp kernel (greater by 0.64 ± 0.21 mm, P < .01) and 3DRA (greater by 0.68 ± 0.19 mm, P < .01). There was no statistically significant difference between 3DRA and the sharp kernel CTA measurements. Neck measurements correlated well between the H60f kernel and 3DRA but not between the H20f Kernel and 3DRA (R 0.97 vs 0.86).

CONCLUSION:

H60f sharp CTA kernel reconstruction provides more accurate anatomic characterization of cerebral aneurysms than the H20f smooth kernel at the expense of less visually pleasing reconstructions. Because it does not require additional contrast, radiation, or imaging hardware and is more similar to 3DRA, it may aid in selecting the appropriate treatment strategy before to evaluation by catheter-based angiography.

Use of CT angiography and digital subtraction angiography in patients with ruptured cerebral aneurysm: evaluation of a large multihospital data base

BACKGROUND AND PURPOSE

Both CT angiography and digital subtraction angiography are used to detect aneurysms in patients with subarachnoid hemorrhage. We examined a large multihospital data base to determine how practice is evolving with regard to the use of CT angiography and DSA in patients with ruptured cerebral aneurysm.

MATERIALS AND METHODS

The Premier Perspective data base was used to identify hospitalizations of patients treated with clipping or coiling of ruptured cerebral aneurysms from 2006-2011. Billing information was used to determine pretreatment and posttreatment use of DSA and CT angiography during hospitalization.

RESULTS

A total of 4972 patients (1022 clipping, 3950 coiling) at 116 hospitals were identified. The percentage of patients with SAH who underwent pretreatment CT angiography significantly increased from 20% in 2006 to 44% in 2011 (P < .0001), whereas the percentage of patients who underwent DSA remained unchanged from 96-94% (P = .28). This CT angiography trend was observed in coiling patients (17-42%, P < .0001) and clipping patients (32-54%, P < .0001). There was a significant increase in the percentage of patients who underwent posttreatment imaging from 41% in 2006 to 48% in 2011 (P = .0037). This trend was observed in clipping patients (33-65%, P < .0001) but not coiling patients (43-45%, P = .62).

CONCLUSIONS

For the pretreatment evaluation of ruptured aneurysms, the use of CT angiography increased from 2006-2011 without a corresponding decrease in the use of DSA. These results raise the question of potential redundancy without added clinical value of the second test.

Cost-effectiveness of CTA, MRA and DSA in patients with non-traumatic subarachnoid haemorrhage

Objectives

Intra-arterial digital subtraction angiography (DSA), magnetic resonance angiography (MRA) and computed tomographic angiography (CTA) are imaging modalities used for diagnostic work-up of non-traumatic subarachnoid haemorrhage. The aim of our study was to compare the cost-effectiveness of MRA, DSA and CTA in the first year after the bleed.

Methods

A decision model was used to calculate costs and benefits (in quality-adjusted life-years [QALYs]) that accrued to cohorts of 1,000 patients. Costs and characteristics of diagnostic tests, therapy, patients’ quality of life and associated costs were respected. The diagnostic strategy with highest QALYs and lowest costs was considered most cost-effective.

Results

DSA was the most effective diagnostic option, yielding on average 0.6039 QALYs (95 % CI, 0.5761–0.6327) per patient, followed by CTA 0.5983 QALYs (95 % CI, 0.5704–0.6278) and MRA 0.5947 QALYs (95 % CI, 0.5674–0.6237). Cost was lowest for DSA (39,808 €; 95 % CI, 37,182–42,663), followed by CTA (40,748 €; 95 % CI, 37,937–43,831) and MRA (41,814 €; 95 % CI, 38,730–45,146). A strategy of CTA followed by DSA if CTA was negative or coiling deemed not feasible, was as effective as DSA alone at average costs of 39,767€ (95 % CI, 36,903–42,402).

Conclusion

A combined strategy of CTA and DSA was found to be the most cost-effective diagnostic approach.

Main Messages

• We defined a standard model for cost-effectiveness analysis in diagnostic imaging.

• Comparing total 1-year health costs and benefits, CTA is superior to MRA.

• A strategy of combining CTA and DSA was found to be the most cost-effective diagnostic approach.

Coiling of ruptured tiny cerebral aneurysms, feasibility, safety, and durability at midterm follow-up, and individual experience

BACKGROUND AND PURPOSE

The tiny size of cerebral aneurysms represents one of the challenging facets for endovascular treatment, with a high risk for intraoperative rupture (IOR). We report on the treatment of tiny ruptured saccular cerebral aneurysms by coil embolization. All cases were that of £ 2-3 mm aneurysms with at least one of the dimensions < 2 mm.

MATERIALS AND METHODS

Between April 2008 and December 2010, we performed a retrospective analysis of nine consecutive cases of tiny aneurysms treated by coil embolization in our institution.

RESULTS

Coil embolization was successfully performed in nine cases, whereas in one case, intraoperative rupture (IOR) of the fundus was encountered before complete obliteration of the aneurysm expected to be achieved with two coils. Complete occlusion (in n = 7 aneurysms) or near-complete immediate occlusion (in n = 2 aneurysms) was achieved. A total of 18 coils was used for coiling of the nine aneurysms, wherein five aneurysms were coiled with two coils each, two aneurysms with three coils each, and two aneurysms with only one coil each to achieve accepted results. Balloon assistance was used in three cases. Although a minimal coil projection in the parent vessel was seen in three cases, no untoward clinical complications were seen. At mean follow-up (6.7 months, interquartile range (IQR) 3-12 months), digital subtraction angiography (DSA) and magnetic resonance angiography (MRA) in nine patients demonstrated persistent complete occlusion in six of the aneurysms; one aneurysm showed marked filling of the fundus, and two showed neck remnant but did not need retreatment. All patients with available follow-up were independent in day-to-day activities with a modified Rankin score (mRS) of 0 or 1.

CONCLUSIONS

Coil embolization of tiny ruptured cerebral aneurysms is feasible. Careful consideration of the technical issues in treatment of such aneurysms is essential to achieve technical success while avoiding complications.

Recent advances in diagnostic approaches for sub-arachnoid hemorrhage

Sub-arachnoid hemorrhage (SAH) has been easily one of the most debilitating neurosurgical entities as far as stroke related case mortality and morbidity rates are concerned. To date, it has case fatality rates ranging from 32-67%. Advances in the diagnostic accuracy of the available imaging methods have contributed significantly in reducing morbidity associated with this deadly disease. We currently have computed tomography angiography (CTA), magnetic resonance angiography (MRA) and the digital subtraction angiography (DSA) including three dimensional DSA as the mainstay diagnostic techniques. The non-invasive angiography in the form of CTA and MRA has evolved in the last decade as rapid, easily available, and economical means of diagnosing the cause of SAH. The role of three dimensional computed tomography angiography (3D-CTA) in management of aneurysms has been fairly acknowledged in the past. There have been numerous articles in the literature regarding its potential threat to the conventional “gold standard” DSA. The most recent addition has been the introduction of the fourth dimension to the established 3D-CT angiography (4D-CTA). At many centers, DSA is still treated as the first choice of investigation. Although, CT angiography still has some limitations, it can provide an unmatched multi-directional view of the aneurysmal morphology and its surroundings including relations with the skull base and blood vessels. We study the recent advances in the diagnostic approaches to SAH with special emphasis on 3D-CTA and 4D-CTA as the upcoming technologies.

Diagnostic yield of catheter angiography in patients with subarachnoid hemorrhage and negative initial noninvasive neurovascular examinations

BACKGROUND AND PURPOSE

The yield of DSA in patients with SAH and negative initial noninvasive neurovascular examinations (CTA or MRA) is not well-understood. This study aimed to determine the yield of DSA for the detection of causative vascular lesions in this clinical scenario.

MATERIALS AND METHODS

We examined the yield of DSA for the detection of causative vascular lesions in a cohort of patients presenting to our institution with SAH and negative initial noninvasive neurovascular examinations during a 5-year period. Two experienced neuroradiologists independently evaluated the NCCT to determine the SAH pattern (diffuse, perimesencephalic, or peripheral sulcal) and the catheter angiograms to assess the presence of a causative vascular lesion.

RESULTS

Fifty-five patients were included in the study, with a mean age of 58.2 years (median, 58 years; range, 25-88 years). Twenty-eight patients were men (50.9%), and 27 were women (49.1%). The initial noninvasive examination was a CTA in 47 patients (85.5%) and an MRA in 8 patients (14.5%). Thirty-three patients had diffuse SAH (60%); 11, perimesencephalic SAH (20%); and 11, peripheral sulcal SAH (20%). DSA demonstrated a causative vascular lesion in 6 patients (10.9%), 5 of whom had diffuse SAH (yield of 15.2%) and 1 of whom had peripheral sulcal SAH (yield of 9.1%). No causative vascular lesions were found in patients with perimesencephalic SAH.

CONCLUSIONS

DSA is a valuable tool in the evaluation of patients with diffuse and peripheral sulcal SAH who have negative initial noninvasive neurovascular examinations, demonstrating a causative vascular lesion in 15.2% and 9.1% of patients, respectively.

Diagnostic yield of computed tomography angiography and magnetic resonance angiography in patients with catheter angiography-negative subarachnoid hemorrhage

OBJECT

The yield of CT angiography (CTA) and MR angiography (MRA) in patients with subarachnoid hemorrhage (SAH) who have a negative initial catheter angiogram is currently not well understood. This study aims to determine the yield of CTA and MRA in a prospective cohort of patients with SAH and a negative initial catheter angiogram.

METHODS

From January 1, 2005, until September 1, 2010, the authors instituted a prospective protocol in which patients with SAH-as documented by noncontrast CT or CSF xanthochromia and a negative initial catheter angiogram- were evaluated using CTA and MRA to assess for causative cerebral aneurysms. Two neuroradiologists independently evaluated the noncontrast CT scans to determine the SAH pattern (perimesencephalic or not) and the CT and MR angiograms to assess for causative cerebral aneurysms.

RESULTS

Seventy-seven patients were included, with a mean age of 52.8 years (median 54 years, range 19-88 years). Fifty patients were female (64.9%) and 27 male (35.1%). Forty-three patients had nonperimesencephalic SAH (55.8%), 29 patients had perimesencephalic SAH (37.7%), and 5 patients had CSF xanthochromia (6.5%). Computed tomography angiography demonstrated a causative cerebral aneurysm in 4 patients (5.2% yield), all of whom had nonperimesencephalic SAH (9.3% yield). Mean aneurysm size was 2.6 mm (range 2.1-3.3 mm). Magnetic resonance angiography demonstrated only 1 of these aneurysms. No causative cerebral aneurysms were found in patients with perimesencephalic SAH or CSF xanthochromia.

CONCLUSIONS

Computed tomography angiography is a valuable adjunct in the evaluation of patients with nonperimesencephalic SAH who have a negative initial catheter angiogram, demonstrating a causative cerebral aneurysm in 9.3% of patients.

Diagnostic yield of repeat catheter angiography in patients with catheter and computed tomography angiography negative subarachnoid hemorrhage

BACKGROUND

The yield of repeat catheter angiography in patients with subarachnoid hemorrhage (SAH) who have negative initial catheter and computed tomography (CT) angiograms is not well understood.

OBJECTIVE

To determine the yield of repeat catheter angiography in a prospective cohort of patients with SAH and negative initial catheter and CT angiograms.

METHODS

From January 1, 2005, until September 1, 2010, we instituted a prospective protocol in which patients with SAH documented by noncontrast CT (NCCT) or cerebrospinal fluid (CSF) xanthochromia and negative initial catheter and CT angiograms were evaluated with repeat catheter angiography 7 days and 3 months after presentation to assess for causative vascular abnormalities.

RESULTS

Seventy-two patients were included, with a mean age of 53.1 years (median, 53.5 years; range, 19-88 years). Forty-six patients were female (63.9%) and 26 male (36.1%). Thirty-nine patients had nonperimesencephalic SAH (54.2%), 29 patients had perimesencephalic SAH (40.3%), and 4 patients had CSF xanthochromia (5.5%). The first repeat catheter angiogram performed 7 days after presentation demonstrated a causative vascular abnormality in 3 patients (yield of 4.2%), 2 of which had nonperimesencephalic SAH (yield of 5.1%), and 1 had perimesencephalic SAH (yield of 3.4%). The second repeat catheter angiogram performed in 43 patients (59.7%) did not demonstrate any causative vascular abnormalities. No causative abnormalities were found in patients with CSF xanthochromia.

CONCLUSION

Repeat catheter angiography performed 7 days after presentation is valuable in the evaluation of patients with SAH who have negative initial catheter and CT angiograms, demonstrating a causative vascular abnormality in 4.2% of patients.

ε-Aminocaproic Acid in Angiographically Negative Subarachnoid Hemorrhage Patients Is Safe: A Retrospective Review of 83 Consecutive Patients

Background:

ε-Aminocaproic acid (EACA) has been used to reduce the rate of cerebral aneurysm rerupture before definitive treatment. In centers administering EACA to patients with a subarachnoid hemorrhage (SAH), patients eventually diagnosed with angiographically negative subarachnoid hemorrhage (ANSAH) may also initially receive EACA, perhaps placing them at increased risk for ischemic complications.

Objective:

To evaluate the effect of short-term EACA on outcomes and secondary measures in patients with ANSAH.

Methods:

We conducted a retrospective study of 454 consecutive SAH patients over a 2-year period under a current protocol for EACA use. Patients were excluded if a source for the SAH was discovered, yielding a total of 83 ANSAH patients. The patients were assigned to groups that did or did not receive EACA. The primary end points of the study were ischemic complications, pulmonary emboli, vasospasm, ventriculoperitoneal shunting rates, and outcomes.

Results:

Statistical analysis yielded no significant difference between the 2 arms with respect to any of the end points: vasospasm (P = .65), deep vein thrombosis (P = .51), pulmonary embolism (P = 1.0), stroke (P = 1.0), myocardial infarction (P = 1.0), and ventriculoperitoneal shunt (P = .57). There was no statistically significant outcome difference using the modified Rankin Scale (P = .30).

Conclusion:

Short-term (&lt;72 hour) application of EACA does not result in an increase in adverse events in patients with ANSAH.

Current imaging assessment and treatment of intracranial aneurysms

OBJECTIVE

This article reviews current neuroimaging techniques used for screening, diagnosis, and follow-up of patients with intracranial aneurysms as well as neuroendovascular therapeutic options available to patients.

CONCLUSION

The diagnosis and management of intracranial aneurysms have evolved dramatically in the past 20 years. MR angiography and CT angiography allow radiologists to reliably and noninvasively diagnose most intracranial aneurysms. Nonoperative endovascular techniques for treating intracranial aneurysms are now making treatment increasingly safer and more effective.

Pediatric intracranial aneurysms

Intracranial pediatric aneurysms arising in children are rare. The treatment of these lesions requires both an understanding of their unique features as well as surgical, interventional, and pediatric critical care expertise offered through a multidisciplinary setting. The patient population, clinical presentation, complications, and trends in treatments are discussed in this article.

Thrombosis and subsequent recanalization of a ruptured intracranial aneurysm in 2 children, demonstrating the value of repeating catheter angiography after an initial negative study

The cases of 2 children with true aneurysmal subarachnoid hemorrhages (SAHs) and initial false-negative angiograms are reported. In both cases, the initial angiogram was of adequate technical quality and included the projections on which aneurysms were later documented. There was no significant vasospasm at the time of initial angiography; therefore, transient aneurysm sac thrombosis was the most likely explanation for the initial false-negative studies. It is particularly interesting to note that 1 of the 2 patients had a pattern of hemorrhage compatible with the most limited definition of a perimesencephalic SAH, that is, a small prepontine cistern hemorrhage. If a second angiogram had been deemed unnecessary based on that criterion alone, a ruptured basilar tip aneurysm would have escaped detection and treatment.

Aneurysmal subarachnoid hemorrhage diagnosis with computed tomographic angiography and OsiriX

PURPOSE

Recent advances in computed tomographic angiography (CTA) have resulted in its replacing digital subtraction angiography (DSA). However, CTA requires a powerful workstation and experienced technicians for image postprocessing. OsiriX, a free open-source medical imaging software with powerful three-dimensional (3D) capability, enables neurosurgeons to perform 3D rendering without extensive training. In this study, we examined the sensitivity and specificity of CTA with OsiriX as the primary diagnostic tool for intracranial aneurysms.

METHOD

From May 2006 to March 2009, 121 patients with spontaneous subarachnoid hemorrhage (SAH) underwent CTA. The CTA source images were 3D rendered by neurosurgeons using OsiriX. All the possible locations for aneurysms were carefully reviewed. DSA was performed on every patient in any of the following conditions: for negative CTA findings, after surgical clipping of aneurysms or before transarterial embolization of aneurysms.

RESULT

Of the 121 patients, 8 were excluded because DSA data were not available. In the remaining 113 patients, 20 patients had negative CTA findings. CTA with OsiriX detected 106 aneurysms in 93 patients, of which 103 were confirmed by DSA or postoperative DSA; 3 infundibular dilated pouches of small arteries were mistaken for aneurysms. Two anterior communicating artery aneurysms (1.5 mm and 1 mm) were missed by CTA from among all 113 patients. The sensitivity and specificity of CTA for detecting aneurysms on a per-patient basis were 98.9% and 100%, respectively. The sensitivity and specificity of CTA for detecting aneurysms on a per-aneurysm basis for detecting aneurysms were 98.1% and 86.3%, respectively.

CONCLUSION

CTA with OsiriX enables accurate detection of intracranial aneurysms. Cerebral DSA should be reserved for those patients with negative CTA findings.

Reporting standards for endovascular repair of saccular intracranial cerebral aneurysms

BACKGROUND AND PURPOSE

The goal of this article is to provide consensus recommendations for reporting standards, terminology, and written definitions when reporting on the radiological evaluation and endovascular treatment of intracranial, cerebral aneurysms. These criteria can be used to design clinical trials, to provide uniformity of definitions for appropriate selection and stratification of patients, and to allow analysis and meta-analysis of reported data.

METHODS

This article was written under the auspices of the Joint Writing Group of the Technology Assessment Committee, Society of NeuroInterventional Surgery, Society of Interventional Radiology; Joint Section on Cerebrovascular Neurosurgery of the American Association of Neurological Surgeons and Congress of Neurological Surgeons; and Section of Stroke and Interventional Neurology of the American Academy of Neurology. A computerized search of the National Library of Medicine database of literature (PubMed) from January 1991 to December 2007 was conducted with the goal to identify published endovascular cerebrovascular interventional data about the assessment and endovascular treatment of cerebral aneurysms useful as benchmarks for quality assessment. We sought to identify those risk adjustment variables that affect the likelihood of success and complications. This article offers the rationale for different clinical and technical considerations that may be important during the design of clinical trials for endovascular treatment of cerebral aneurysms. Included in this guidance article are suggestions for uniform reporting standards for such trials. These definitions and standards are primarily intended for research purposes; however, they should also be helpful in clinical practice and applicable to all publications.

CONCLUSIONS

The evaluation and treatment of brain aneurysms often involve multiple medical specialties. Recent reviews by the American Heart Association have surveyed the medical literature to develop guidelines for the clinical management of ruptured and unruptured cerebral aneurysms. Despite efforts to synthesize existing knowledge on cerebral aneurysm evaluation and treatment, significant inconsistencies remain in nomenclature and definition for research and reporting purposes. These operational definitions were selected by consensus of a multidisciplinary writing group to provide consistency for reporting on imaging in clinical trials and observational studies involving cerebral aneurysms. These definitions should help different groups to publish results that are directly comparable.

State of the art head and neck imaging for the endovascular specialist

Recent technologic advances including multidetector CT, dynamic CT angiography, high-field MR imaging, four-dimensional MR angiography, and physiologic studies, such as perfusion imaging, have revolutionized the imaging work-up of head, neck, and skull base lesions. These techniques not only provide accurate diagnostic information, but also help plan endovascular therapy. The future holds great promise for interventional neuroradiologists because excellent imaging tools are becoming available that are capable of providing morphologic, hemodynamic, and physiologic information. Furthermore, availability of faster, real-time guidance systems and hybrid systems improves the ability to perform procedures not only in a rapid and safe manner but also with great precision.

Multi-detector row CT angiography with direct intra-arterial contrast injection for the evaluation of neurovascular disease: technique, applications, and initial experience

The purpose of this study was to evaluate the usefulness of 64-section multi-detector row CT angiography (CTA) with direct intra-arterial contrast injection (IA-CTA) for the evaluation of neurovascular disease. This technique was used in 11 patients at our institution. All studies were technically successful, and there were no complications. Small vascular malformations were mapped easily on high-resolution IA-CTA images, enabling microsurgical resection or stereotactic radiosurgery. In a similar fashion, additional morphologic features were revealed on IA-CTA images not seen on standard 2D and 3D digital subtraction angiography. Of 11 patients undergoing IA-CTA, 7 patients had further anatomic clarity of the small arteriovenous fistula/malformation and 4 patients had changes in the treatment plan on the basis of the IA-CTA findings.

Reporting standards for endovascular repair of saccular intracranial cerebral aneurysms

BACKGROUND AND PURPOSE

The goal of this article is to provide consensus recommendations for reporting standards, terminology, and written definitions when reporting on the radiological evaluation and endovascular treatment of intracranial, cerebral aneurysms. These criteria can be used to design clinical trials, to provide uniformity of definitions for appropriate selection and stratification of patients, and to allow analysis and meta-analysis of reported data.

METHODS

This article was written under the auspices of the Joint Writing Group of the Technology Assessment Committee, Society of NeuroInterventional Surgery, Society of Interventional Radiology; Joint Section on Cerebrovascular Neurosurgery of the American Association of Neurological Surgeons and Congress of Neurological Surgeons; and Section of Stroke and Interventional Neurology of the American Academy of Neurology. A computerized search of the National Library of Medicine database of literature (PubMed) from January 1991 to December 2007 was conducted with the goal to identify published endovascular cerebrovascular interventional data about the assessment and endovascular treatment of cerebral aneurysms useful as benchmarks for quality assessment. We sought to identify those risk adjustment variables that affect the likelihood of success and complications. This article offers the rationale for different clinical and technical considerations that may be important during the design of clinical trials for endovascular treatment of cerebral aneurysms. Included in this guidance article are suggestions for uniform reporting standards for such trials. These definitions and standards are primarily intended for research purposes; however, they should also be helpful in clinical practice and applicable to all publications.

CONCLUSIONS

The evaluation and treatment of brain aneurysms often involve multiple medical specialties. Recent reviews by the American Heart Association have surveyed the medical literature to develop guidelines for the clinical management of ruptured and unruptured cerebral aneurysms. Despite efforts to synthesize existing knowledge on cerebral aneurysm evaluation and treatment, significant inconsistencies remain in nomenclature and definition for research and reporting purposes. These operational definitions were selected by consensus of a multidisciplinary writing group to provide consistency for reporting on imaging in clinical trials and observational studies involving cerebral aneurysms. These definitions should help different groups to publish results that are directly comparable.

Coil embolization of very small (2 mm or smaller) berry aneurysms: feasibility and technical issues

BACKGROUND AND PURPOSE

The very small size of cerebral aneurysms is considered to be one of the limitations for endovascular treatment, with a high risk for intraoperative rupture. We report on treatment of very small saccular ruptured cerebral aneurysms by coil embolization. All the cases were of 2-mm aneurysms with at least 1 of the dimensions being less than 2 mm.

MATERIALS AND METHODS

We performed retrospective analysis of 7 consecutive cases of very small aneurysms treated by coil embolization in our institution between July 2006 and April 2008.

RESULTS

3D rotational angiography (3DRA) was found to be most accurate in the detection of these aneurysms; in 2 cases, 3DRA revealed the aneurysms after results on digital subtraction angiography (DSA) were considered to be negative. Coil embolization was successfully performed in 6 cases, whereas in 1 case, spontaneous thrombosis occurred after microcatheter placement. Complete (n = 5) or near complete (n = 2) immediate occlusion was seen. A single soft coil was used in all cases with the shortest available length. Balloon assistance was used in 3 cases. Although minimal coil projection in the parent vessel was seen in 3 cases, no untoward clinical complication was seen. Follow-up DSA and MR angiography in 4 patients demonstrated persistent occlusion (n = 3) or progressive thrombosis (n = 1) of the aneurysms. All of the patients with available follow-up are independent in day-to-day activities with a modified Rankin Score (mRS) of 0 or 1.

CONCLUSIONS

Coil embolization of very small ruptured cerebral aneurysms is feasible. Careful consideration of the technical issues in treatment of these cases is essential to achieve technical success while avoiding complications.