Arterial spin labeling as an ancillary assessment to postoperative conventional angiogram in pediatric moyamoya disease

OBJECTIVE Digital subtraction angiography (DSA) is commonly performed after pial synangiosis surgery for pediatric moyamoya disease to assess the degree of neovascularization. However, angiography is invasive, and the risk of ionizing radiation is a concern in children. In this study, the authors aimed to identify whether arterial spin labeling (ASL) can predict postoperative angiogram grading. In addition, they sought to determine whether patients who underwent ASL imaging without DSA had similar postoperative outcomes when compared with patients who received ASL imaging and postoperative DSA. METHODS The medical records of pediatric patients who underwent pial synangiosis for moyamoya disease at a quaternary children’s hospital were reviewed during a 10-year period. ASL-only and ASL+DSA cohorts were analyzed. The frequency of preoperative and postoperative symptoms was analyzed within each cohort. Three neuroradiologists assigned a visual ASL grade for each patient indicating the change from the preoperative to postoperative ASL perfusion sequences. A postoperative neovascularization grade was also assigned for patients who underwent DSA. RESULTS Overall, 21 hemispheres of 14 patients with ASL only and 14 hemispheres of 8 patients with ASL+DSA were analyzed. The groups had similar rates of MRI evidence of acute or chronic stroke preoperatively (61.9% in the ASL-only group and 64.3% in the ASL+DSA group). In the entire cohort, transient ischemic attack (TIA) (p = 0.027), TIA composite (TIA or unexplained neurological symptoms; p = 0.0006), chronic headaches (p = 0.035), aphasia (p = 0.019), and weakness (p = 0.001) all had decreased frequency after intervention. The authors found a positive association between revascularization observed on DSA and the visual ASL grading (p = 0.048). The visual ASL grades in patients with an angiogram indicating robust neovascularization demonstrated improved perfusion when compared with the ASL grades of patients with a poor neovascularization. CONCLUSIONS Noninvasive ASL perfusion imaging had an association with postoperative DSA neoangiogenesis following pial synangiosis surgery in children. There were no significant postoperative stroke differences between the ASL-only and ASL+DSA cohorts. Both cohorts demonstrated significant improvement in preoperative symptoms after surgery. Further study in larger cohorts is necessary to determine whether the results of this study are validated in order to circumvent the invasive catheter angiogram.

Tentorial meningioma supplied by a marginal tentorial artery arising from the superior cerebellar artery: Anatomic and technical considerations

Background and importance The marginal tentorial artery runs over the free edge of the tentorium. Different origins have been described, always involving branches of the carotid artery. We report the superior cerebellar artery as an unknown origin of this artery. We developed our strategy in a case of a tentorial meningioma mainly supplied by this artery. Clinical presentation A 53-year-old man was admitted in our institution for the surgical treatment of a large tentorial and petroclival meningioma. A 2D conventional angiogram was insufficient to detect the tumoral blush. A 3D digital subtraction angiogram (DSA) of the vertebral artery highlighted a blush arising from a marginal tentorial artery fed by the superior cerebellar artery. Selective embolization of this branch led to significant devascularization of the tumor. A total tumor resection was performed 24 h after embolization without complication. The dural medial tentorial artery of the superior cerebellar artery is relatively unknown and courses at the inferior surface of the tentorium. We report the first case in which the marginal tentorial artery arises from this artery. Major bleeding may result from its section or its avulsion from the superior cerebellar artery during surgery; its preoperative diagnosis is thus essential. In this case, a 3D-DSA with dual volume visualization was more sensitive than a 2D conventional angiogram to detect such an anatomic variant. Conclusion The marginal tentorial artery may originate from the superior cerebellar artery. The recognition of this anatomic variant may be essential to avoid hemorrhagic complications during surgery of hypervascular tumors of the tentorium.

A Rare Case of Angina Pectoris with the Longest Ectopic Left Main Coronary Artery Arising from Right Sinus of Valsalva and a Prepulmonic Course

Knowledge of the morphoanatomical characteristics of the main trunk of the left coronary artery as well as its variations is cornerstone of hemodynamic, correct interpretation of coronary angiogram and for revascularization purpose. The left main coronary artery (LMCA) ranges from 3 to 6 mm in diameter and may be up to 10 to 15 mm in length in humans. We here report a case of the longest anomalous LMCA (56 mm) reported so far in a 35-year-old man with chronic stable angina arising from right sinus of valsalva as seen on conventional angiogram and multidetector computerized tomogram (MDCT).

Abstract W MP22: Impact of Difference in Definitions of M1 and M2 segment of Middle Cerebral Artery on Acute Stroke Endovascular Therapy

BACKGROUND: The involvement of the different segment of middle cerebral artery has different implications in terms of acute stroke endovascular therapy as learnt from recent trials. It has been suggested in prior trials that M1 segment occlusion might benefit more from acute endovascular therapy as compared to M2 segment. Ongoing trials have different definitions for segments of middle cerebral artery. METHODS: Retrospective review of latest 71 cases of either M1/M2 confirmed on Digital Subtraction Angiography (DSA) in prospectively maintained database of acute stroke interventions at our institute is performed. Of these, 49 cases have CTA performed prior to DSA (69%). Stroke Neurologist has blindly reviewed CTA angiogram. Conventional angiogram findings are considered accurate for the exact site of occlusion. Two definitions from REVASCAT trial and SWIFT PRIME trial are then scored based on CTA and assessed in respect to findings in DSA RESULTS: As per RESVASCAT defintion, 34 out of 49 cases on CTA/MRA (69%) have M1 occlusion on CTA. Of these 34 cases, 32 are then found to have M1 occlusion on DSA as well. The number of M2 occlusions were 9 out of 49 (18%) on CTA and all of them were found to have M2 occlusion of DSA as well. The accuracy of RESVASCAT definition of M1 and M2 were 32/34 (94%) are 9/9 (100%) respectively. As per SWIFT PRIME definition, 27 out of 49 cases (58%) on CTA/MRA have M1 occlusions on CTA. Of these 27 cases, all cases were found to have M1 occlusions on DSA as well. The number of M2 occlusions were 15 out of 49 (31%) on CTA and 9 were found to have M2 occlusions on DSA. The accuracy of SWIFT PRIME definition of M1 and M2 were 27/27 (100%) and 9/15(60%). 6 cases (12%) with M1 occlusions on CTA as per REVASCAT definition were defined as M2 occlusions as per SWIFT PRIME. CONCLUSIONS: The examination of angiographic data found discrepancies between these two definitions. The accuracy of REVASCAT definition was better for M2 whereas the accuracy of SWIFT PRIME definition was better for M1. The different definition of middle cerebral artery segments could potentially lead to discrepancies in the eligibility criteria for acute endovascular interventions. The criteria used in determining the M1 and M2 segments should be consistent across the field.

Acute Hemiparesis in a Child as a Presenting Symptom of Hemispheric Cerebral Proliferative Angiopathy

A 9-year-old girl with a several-month history of unilateral intermittent headaches presented to the hospital with worsening headaches and unsteadiness. Neurologic exam was positive for a mild right hemiparesis and right homonymous hemianopsia. Noncontrast computed tomography revealed an engorged sagittal and straight sinus with prominent cortical veins concerning an arteriovenous malformation and the patient was admitted to the pediatric intensive care unit. Computed tomography angiogram demonstrated a left hemispheric vascular malformation, without evidence of dural arteriovenous fistula on conventional angiogram consistent with a diagnosis of cerebral proliferative angiopathy. There was no evidence of infarct on magnetic resonance imaging, and the patient’s symptoms were completely resolved within 24 hours. Cerebral proliferative angiopathy is a rare but important vascular malformation distinct from classic arteriovenous malformations that may present with stroke-like symptoms in childhood.

Angioarchitecture Determines Obliteration Rate After Radiosurgery in Brain Arteriovenous Malformations

ABSTRACT BACKGROUND: Radiosurgery as a potential treatment modality for brain arteriovenous malformations (AVM) has 60% to 90% obliteration rates. OBJECTIVE: To test whether AVM angioarchitecture determines obliteration rate after radiosurgery. METHODS: This study was a retrospective analysis of 139 patients with AVM who underwent radiosurgery. Multiple angioarchitectural characteristics were reviewed on conventional angiogram on the day of radiosurgery: enlargement of feeding arteries, flow-related or intranidal aneurysms, perinidal angiogenesis, arteriovenous transit time, nidus type, venous ectasia, focal pouches, venous rerouting, and presence of a pseudophlebitic pattern. The radiation plan was reviewed for nidus volume and eloquence of AVM location. A chart review was performed to determine clinical presentation and previous treatment. Outcome was dichotomized into complete/incomplete obliteration, and various statistics were performed, examining whether outcome status was associated with the investigated factors. RESULTS: Marginal dose ranged from 15 to 25 Gy (mean, 18.8 Gy), with lower doses prescribed in eloquent locations. Sizes of AVMs ranged from 0.08 to 21cm3 (mean, 3.78 ± 4.19 cm3). Complete AVM obliteration was achieved in 92 patients (66%) and was related to these independent factors: noneloquent location (odds ratio [OR], 3.20), size (OR, 0.88), low flow (OR, 3.47), no or mild arterial enlargement (OR, 3.32), and absence of perinidal angiogenesis (OR, 2.61). Concerning the 3 last angioarchitectural characteristics, if no or only a single factor was present in an individual patient (n = 92 patients), obliteration was observed in 74 (80%); if 2 or 3 factors were present (n = 47), obliteration was observed in 18 patients (38%; OR, 6.62). CONCLUSION: Angioarchitectural factors that indicate high flow are associated with a lower rate of AVM obliteration after radiosurgery.

Clinical significance of the flow gap in carotid magnetic resonance angiography

✓ Magnetic resonance (MR) angiography offers a safe, noninvasive alternative to conventional angiography in patients with suspected carotid stenosis; however, it tends to overestimate the severity of stenosis. Loss of the MR signal with a resulting flow gap is a frequent finding in cases of high-grade stenosis. The authors undertook this study to define the range of carotid stenosis associated with a flow gap on two-dimensional time-of-flight (2DTF)-MR angiography. Blinded evaluations were made of 102 common carotid bifurcations in 51 patients who had undergone both conventional angiography and 2DTF-MR angiography. The percent of diameter stenosis was calculated from the conventional angiogram using the method adopted by the Asymptomatic Carotid Atherosclerosis Study (ACAS) trial. An MR flow gap was noted if there was a segment of the vessel that was completely free of signal with a reappearance of the signal distally. According to conventional angiography, the minimum percentage of stenosis associated with a flow gap is 56%. Flow gaps were present in 20 of 22 arteries (sensitivity 91%) with stenosis of 60% or more and in two of the 66 arteries (specificity 97%) with less than 60% stenosis. Flow gaps were present in all arteries with stenosis of 70% or more. Complete occlusion was correctly identified in 10 of 10 cases. These results demonstrate that the presence of a flow gap on 2DTF-MR angiography is a reliable marker of clinically significant carotid stenosis (measuring 60% or more), with sensitivity and specificity comparable to duplex carotid ultrasound. In addition, MR angiography can be used to screen the intracranial circulation for significant vascular pathology in patients being considered for carotid endarterectomy.