Flow diverter stenting for intracranial aneurysms in the pediatric population: Two case reports and literature review

The Pipeline Embolization Device (PED) is a flow-diverting intraluminal device that is approved for use in adults 18 years or older with internal carotid artery aneurysms. However, it can also be used off-label in pediatric patients with aneurysms that cannot be resolved with traditional endovascular treatments. Herein, we present two cases of flow diversion in the pediatric population with complete obliteration of the aneurysm and excellent outcomes. Flow diversion has been shown to be a safe endovascular option in treating complex aneurysms in children. Larger-sized, multicenter trials are encouraged to compare outcomes between flow diversion and other aneurysm treatment options given the rarity of pediatric aneurysms.

Intracranial Vascular Procedures

Anesthesia for intracranial vascular procedures is complex because it requires a balance of several competing interests and potentially can result in significant morbidity and mortality. Frequently, periods of ischemia, where perfusion must be maintained, are combined with situations that are high risk for hemorrhage. This review discusses the basic surgical approach to several common pathologies (intracranial aneurysms, arteriovenous malformations, and moyamoya disease) along with the goals for anesthetic management and specific high-yield recommendations.

Towards multi-modal data fusion for super-resolution and denoising of 4D-Flow MRI

4D-Flow magnetic resonance imaging (MRI) has enabled in vivo time-resolved measurement of three-dimensional blood flow velocities in the human vascular system. However, its clinical use has been hampered by two main issues, namely, low spatio-temporal resolution and acquisition noise. While patient-specific computational fluid dynamics (CFD) simulations can address the resolution and noise issues, its fidelity is impacted by accuracy of estimation of boundary conditions, model parameters, vascular geometry, and flow model assumptions. In this paper a scheme to address limitations of both modalities through data-fusion is presented. The solutions of the patient-specific CFD simulation are characterized using proper orthogonal decomposition (POD). Next, a process of projecting the 4D-Flow MRI data onto the POD basis and projection coefficient mapping using generalized dynamic mode decomposition (DMD) enables simultaneous super-resolution and denoising of 4D-Flow MRI. The method has been tested using numerical phantoms derived from patient-specific aneurysmal geometries and applied to in vivo 4D-Flow MRI data.

Persistent Hypotension and Cerebral Swelling Resulting From Mesenteric Traction Syndrome After Omental-to-Pial Pedicle Flap Transfer in a Young Woman With Refractory Moyamoya Disease: A Case Report

Superficial temporal arterial to middle cerebral arterial anastomosis is often the initial surgical treatment of Moyamoya disease. In refractory cases, placing a pedicle flap of omentum over the ischemic brain has resulted in clinical improvement or stabilization of symptoms. We present a case of persistent mesenteric traction syndrome manifested by hypotension unresponsive to conventional doses of vasopressors during and after pulling the omentum to the brain. As prostacyclin is a major mediator of hypotension from mesenteric traction syndrome and also a cerebral vasodilator, we discuss the possibility that brain swelling may be a manifestation of mesenteric traction syndrome.

Decreased Superior Sagittal Sinus Diameter and Jugular Bulb Narrowing Are Associated with Poor Clinical Outcome in Vein of Galen Arteriovenous Malformation

BACKGROUND AND PURPOSE

Few clinical and imaging findings are known to be associated with poor outcome in neonates and infants with vein of Galen arteriovenous malformations. In the present consecutive series of 35 patients, we evaluated both the diameter of the superior sagittal sinus at onset and the diameter of the jugular bulb on follow-up as potential factors related to poor outcome.

MATERIALS AND METHODS

Thirty-five consecutive neonates and infants who were prospectively collected in a single-center data base were included in this review. Outcome was assessed by using the Bicêtre Outcome Score. Both the absolute diameter of the superior sagittal sinus and its ratio to the biparietal diameter were measured at onset, compared with age-matched controls, and correlated to patient outcome.

RESULTS

The diameter of the superior sagittal sinus at onset and its ratio to the biparietal diameter were significantly smaller in the vein of Galen arteriovenous malformation population compared with the matched population (P = .0001) and were correlated significantly with a risk of poor clinical outcome (P = .008). Development of jugular bulb narrowing was also related to poor clinical outcome (P < .0001).

CONCLUSIONS

Decreased superior sagittal sinus diameter may reflect a decrease of cerebral blood flow due to cerebral arterial steal and intracranial hydrovenous disorders. This finding may be considered cerebral blood flow deterioration and thus taken into consideration in the management decisions for patients with vein of Galen arteriovenous malformations. Likewise, our data suggest that progressive jugular bulb narrowing may indicate earlier intervention to prevent severe narrowing.

High-Resolution Vessel Wall Magnetic Resonance Imaging in Angiogram-Negative Non-Perimesencephalic Subarachnoid Hemorrhage

PURPOSE

Standard magnetic resonance imaging (MRI) rarely identifies the cause of hemorrhage in patients with an angiogram-negative, non-perimesencephalic subarachnoid hemorrhage (SAH). Yet up to 10 % of these patients have recurrent hemorrhage. The aim of the study was to explore the potential role of high-resolution contrast-enhanced 3-Tesla vessel wall-MRI in patients with angiogram-negative SAH.

METHODS

We performed intracranial vessel wall-MRI of the circle of Willis using a 3-Tesla scanner in consecutive patients presenting with a spontaneous, angiogram-negative, non-perimesencephalic SAH. Vessel wall-MRI included T1-, T2-, and gadolinium-enhanced T1-weighted two-dimensional black-blood sequences in multiple planes (voxel size 0.4 × 0.4 × 2.0 mm). Two neuroradiologists independently scored abnormalities of the arterial wall.

RESULTS

In all, 11 patients (mean age 59 years) underwent vessel wall-MRI. A total of seven patients had vessel wall abnormalities despite normal catheter angiography. Two patients had focal abnormalities contiguous with the outer margin of the basilar artery wall for which we considered a differential of ruptured blood blister aneurysm, thrombosed aneurysm, and loculated extramural blood from elsewhere. Two patients had arterial wall enhancement involving multiple arteries, possibly secondary to SAH. Three patients had arterial wall enhancement at sites of dural penetration, remote from the SAH, likely related to age and atherosclerotic risk factors. Vessel wall-MRI did not alter patient management in this cohort.

CONCLUSION

Vessel wall-MRI showed abnormalities in seven patients with angiogram-negative SAH. These findings did not alter patient management, but the findings may be useful for other physicians who choose to perform vessel wall-MRI in this patient population.

Natural history and management of basilar trunk artery aneurysms

BACKGROUND AND PURPOSE

Basilar trunk aneurysms (BTAs), defined as aneurysms distal to the basilar origin and proximal to the origin of the superior cerebellar artery, are rare and challenging to manage. We describe the natural history and management in a consecutive series of BTAs.

METHODS

Between 2000 and 2013, 2522 patients with 3238 aneurysms were referred to our institution for aneurysm management. A retrospective review of this database was conducted to identify all patients with BTAs.

RESULTS

In total, 52 patients had a BTA. Mean age was 56 (SD±18) years. Median clinical follow-up was 33 (interquartile range, 8-86) months, and imaging follow-up was 26 (interquartile range, 2-80.5) months. BTAs were classified into 4 causal subtypes: acute dissecting aneurysms, segmental fusiform ectasia, mural bleeding ectasia, and saccular aneurysms. Multiple aneurysms were more frequently noticed among the 13 saccular aneurysms when compared with overall population (P=0.021). There was preponderance of segmental ectasia or mural bleeding ectasia (P=0.045) in patients presenting with transit ischemic attack/stroke or mass effect. Six patients with segmental and 4 with mural bleeding ectasia demonstrated increasing size of their aneurysm, with 2 having subarachnoid hemorrhage caused by aneurysm rupture. None of the fusiform aneurysms that remained stable bled.

CONCLUSIONS

BTAs natural histories may differ depending on subtype of aneurysm. Saccular aneurysms likely represent an underlying predisposition to aneurysm development because more than half of these cases were associated with multiple intracranial aneurysms. Intervention should be considered in segmental ectasia and chronic dissecting aneurysms, which demonstrate increase in size over time as there is an increased risk of subarachnoid hemorrhage.

Abstract 195: The Natural History and Predictive Factors of Hemorrhage from Choroidal (Intraventricular) Brain Arteriovenous Malformations

Background: The natural history and risk of hemorrhage for patients harbouring choroidal/ intraventricular AVMs is poorly understood. We examined the impact of demographic and angiographic features on the likelihood of future hemorrhage.

Methods: A prospectively maintained database from the Toronto Western Hospital was analyzed. Inclusion criteria were AVMS that were entirely intraventricular and supplied predominantly from choroidal arteries (anterior/ posterior). The rate of hemorrhage over long term follow up was calculated. The impact of baseline clinical and angio-architectural on time to hemorrhage were analyzed using survival analysis and compared with the total AVM population (n = 1018).

Results: 44 patients (median age 27, range 2 - 72 years) identified with choroidal AVMs (4.4% of all AVMs) were followed for 151 patient years. 36 patients (82%) presented with hemorrhage (vs 39% for all AVMs), 28 (77%) of which were predominantly intraventricular. Hemorrhage rates were 7.3%/ year (vs 1.7%/year for all AVMs, HR 2.3, p<0.001). The presence of venous reflux into thalamostriate or cortical veins was a significant independent risk factor for future hemorrhage (HR 1.80, p =0.047) with intranidal aneurysms not significantly associated with future hemorrhage risk (HR = 1.3, p =0.18).

Conclusion: Choroidal AVMs are more likely to present with hemorrhage, particularly of the intraventricular type and are associated with approximately 2-fold greater likelihood of future hemorrhage, especially in the presence of venous reflux.

Natural history and outcome after treatment of unruptured intradural fusiform aneurysms

BACKGROUND AND PURPOSE

Management of unruptured fusiform intracranial aneurysms is controversial because of the paucity of natural history data. We studied their natural history and outcome after treatment.

METHODS

We reviewed our neurovascular database from January 2000 to October 2013. Inclusion criteria were unruptured, intradural fusiform aneurysms with a diameter of <2.5 cm. Criteria were developed to define atherosclerotic aneurysms. For outcome assessment, we used the modified Ranking Scale and aneurysm measurements on serial imaging. Mann-Whittney (continuous) and Fisher exact (categorical) tests were used for risk factor analysis.

RESULTS

For nonatherosclerotic aneurysms (96 patients; 193 person-years follow-up), 1 patient died (rupture) during follow-up (mortality, 0.51% per year) and 8 patients (10%) showed aneurysm progression (risk, 1.6% per year). Risk factors for progression were maximum diameter (>7 mm; odds ratio, 12; 95% confidence interval, 1.4-104) and symptomatic clinical presentation (odds ratio, 16; 95% confidence interval, 3.1-81.4). Of the 23 treated patients, 3 had died (mortality, 12.5%) and 3 had serious disability (modified Ranking Scale, ≥3; 12.5%). For the atherosclerotic aneurysms (25 patients; 97 person-years follow-up), 5 had died (mortality, 5.2% per year) and 13 of 20 (65%) had aneurysm progression (risk, 12% per year). When compared with patients with nonatherosclerotic aneurysms, case fatality (odds ratio, 19.2; 95% confidence interval, 2.1-172) and aneurysm progression (odds ratio, 17.8; 95% confidence interval, 5.3-56) were higher.

CONCLUSIONS

Nonatherosclerotic fusiform intradural aneurysms have a low risk of adverse outcome within the first few years after diagnosis and remain stable unless symptomatic on presentation or >7 mm in maximum diameter. High risks of treatment should be balanced against this benign natural history. Atherosclerotic aneurysms have a worse natural history and may represent a different disease entity.

The effect of spontaneous alterations in brain temperature on outcome: a prospective observational cohort study in patients with severe traumatic brain injury

There are few prospective studies reporting the effect of spontaneous temperature changes on outcome after severe traumatic brain injury (TBI). Where studies have been conducted, results are based on systemic rather than brain temperature per se. However, body temperature is not a reliable surrogate for brain temperature. Consequently, the effect of brain temperature changes on outcome in the acute phase after TBI is not clear. Continuous intraparenchymal brain temperature was measured in consecutive admissions of severe TBI patients during the course of the first 5 days of admission to the intensive care unit (ICU). Patients received minimal temperature altering therapy during their ICU stay. Logistic regression was used to explore the relationship between the initial, the 24-h mean, and the 48-h mean brain temperature with outcome for mortality at 30 days and outcome at 3 months. Multifactorial analysis was performed to account for potential confounders. At the 24-h time point, brain temperature within the range of 36.5°C to 38°C was associated with a lower probability of death (10-20%). Brain temperature outside of this range was associated with a higher probability of death and poor 3-month neurological outcome. After adjusting for other predictors of outcome, low brain temperature was independently associated with a worse outcome. Lower brain temperatures (below 37°C) are independently associated with a higher mortality rate after severe TBI. The results suggest that, contrary to current opinion, temperatures within the normal to moderate fever range during the acute post-TBI period do not impose an additional risk for a poor outcome after severe TBI.

Primary diffuse large B-cell central nervous system lymphoma presenting as an acute space-occupying subdural mass

Primary dural lymphomas are very rare tumors--usually low-grade B-cell lymphomas of mucosa-associated lymphoid tissue type or marginal zone B-cell lymphomas. Primary dural involvement by diffuse large B-cell lymphoma is extremely rare, with only a few cases reported in the literature. The authors present an unusual case of primary dural involvement by a high-grade diffuse large B-cell lymphoma that presented as an acute subdural space-occupying mass and required emergency neurosurgical intervention.

The significance of altered temperature after traumatic brain injury: an analysis of investigations in experimental and human studies: part 2

Raised body temperature is a common occurrence after severe traumatic brain injury (TBI). It is widely accepted that experimental evidence points to a harmful effect of raised temperature both during and after TBI. Consequently, the policy of many neurocritical care units is to implement therapies for body temperature control. This article reviews the evidence that links spontaneous temperature changes with worsened outcome after experimentally-induced and human brain trauma. The current evidence-base and rationale for treatment of raised temperature after TBI is presented with discussion positing areas for further work to explore the notion that raised temperature may not be deleterious in all neurosurgical patients.