Interarm Blood Pressure Difference Revealing a Right-Sided Aortic Arch and Occluded Aberrant Left Subclavian Artery.

We present the case of a 33-year-old patient with a rare combination of a right-sided aortic arch and occluded asymptomatic aberrant left subclavian artery diagnosed after the coincidental finding of an interarm blood pressure difference. Because there were no symptoms of local compression or subclavian steal, conservative management was suggested.

Posterior Cerebral Artery-to-Superior Cerebellar Artery Side-to-Side Bypass via Extreme Lateral Supracerebellar Infratentorial Approach: Technical Note.

BACKGROUND: Difficult-to-treat aneurysms of the distal posterior cerebral artery (PCA) can often be treated by parent artery occlusion. A cerebrovascular bypass can complement PCA occlusion to curb the risk of ischemic complications. An in situ bypass may be considered when the occipital artery or superficial temporal artery cannot serve as a bypass donor. This article describes the use of a side-to-side bypass of superior cerebellar artery as a donor to the PCA via an extreme lateral supracerebellar infratentorial approach (ELSCIT). This bypass approach can be a useful surgical strategy for PCA revascularization. METHODS: A 40-year-old woman underwent a side-to-side PCA-superior cerebellar artery bypass via the ELSCIT approach for to treat a complex and previously coiled PCA aneurysm. The bypass was followed by endovascular aneurysm and parent artery occlusion. RESULTS: Postoperatively, the patient experienced transient, partial trochlear nerve palsy of the left eye without ischemic lesions on magnetic resonance imaging. The clinical condition was stable, and angiography showed a patent bypass and complete aneurysm occlusion 12 months after surgery. CONCLUSIONS: The ELSCIT approach offers access to the medial and distal PCA that is suitable for a side-to-side PCA-superior cerebellar artery bypass. This type of approach and bypass may be of value when revascularization of a P2-P3 portion of the PCA is needed, but a suitable occipital artery or superficial temporal artery is not available.

Can angiographic Flat Detector Computed Tomography blood volume measurement be used to predict final infarct size in acute ischemic stroke?

INTRODUCTION AND PURPOSE: Flat detector computed tomography (FD-CT) technology is becoming more widely available in the angiography suites of comprehensive stroke centers. In patients with acute ischemic stroke (AIS), who are referred for endovascular therapy (EVT), FD-CT generates cerebral pooled blood volume (PBV) maps, which might help in predicting the final infarct area. We retrospectively analyzed pre- and post-recanalization therapy quantitative PBV measurements in both the infarcted and hypoperfused brain areas of AIS patients referred for EVT. MATERIALS AND METHODS: We included AIS patients with large vessel occlusion in the anterior circulation referred for EVT from primary stroke centers to our comprehensive stroke center. The pre- and post-recanalization FD-CT regional relative PBV (rPBV) values were measured between ipsilateral lesional and contralateral non-lesional areas based on final infarct area on post EVT follow-up cross-sectional imaging. Statistical analysis was performed to identify differences in PBV values between infarcted and non-infarcted, recanalized brain areas. RESULTS: We included 20 AIS patients. Mean age was 63 years (ranging from 36 to 86 years). The mean pre- EVT rPBV value was 0.57 (±0.40) for infarcted areas and 0.75 (±0.43) for hypoperfusion areas. The mean differences (Δ) between pre- and post-EVT rPBV values for infarcted and hypoperfused areas were respectively 0.69 (±0.59) and 0.69 (±0.90). We found no significant differences (p > 0.05) between pre-EVT rPBV and ΔrPBV values of infarct areas and hypoperfusion areas. CONCLUSION: Angiographic PBV mapping is useful for the detection of cerebral perfusion deficits, especially in combination with the fill run images. However, we were not able to distinguish irreversibly infarcted tissue from potentially salvageable, hypoperfused brain tissue based on quantitative PBV measurement in AIS patients.

Flat Detector CT with Cerebral Pooled Blood Volume Perfusion in the Angiography Suite: From Diagnostics to Treatment Monitoring.

C-arm flat-panel detector computed tomographic (CT) imaging in the angiography suite increasingly plays an important part during interventional neuroradiological procedures. In addition to conventional angiographic imaging of blood vessels, flat detector CT (FD CT) imaging allows simultaneous 3D visualization of parenchymal and vascular structures of the brain. Next to imaging of anatomical structures, it is also possible to perform FD CT perfusion imaging of the brain by means of cerebral blood volume (CBV) or pooled blood volume (PBV) mapping during steady state contrast administration. This enables more adequate decision making during interventional neuroradiological procedures, based on real-time insights into brain perfusion on the spot, obviating time consuming and often difficult transportation of the (anesthetized) patient to conventional cross-sectional imaging modalities. In this paper we review the literature about the nature of FD CT PBV mapping in patients and demonstrate its current use for diagnosis and treatment monitoring in interventional neuroradiology.

Selective Angiographic Flat Detector Computer Tomography Blood Volume Imaging in Pre-Operative Vascular Mapping and Embolization of Hypervascular Intracranial Tumors-Preliminary Clinical Experience.

Pre-operative embolization of hypervascular intracranial tumors can be performed to reduce bleeding complications during resection. Accurate vascular mapping of the tumor is necessary for both the correct indication setting for embolization and for the evaluation of the performed embolization. We prospectively examined the role of whole brain and selective parenchymal blood volume (PBV) flat detector computer tomography perfusion (FD CTP) imaging in pre-operative angiographic mapping and embolization of patients with hypervascular intracranial tumors. Whole brain FD CTP imaging with a contrast injection from the aortic root and selective contrast injection in the dural feeding arteries was performed in five patients referred for tumor resection. Regional relative PBV values were obtained pre- and post-embolization. Total tumor volumes with selective external carotid artery (ECA) supply volumes and post-embolization devascularized tumor volumes were determined as well. In all patients, including four females and one male, with a mean age of 54.2 years (range 44-64 years), the PBV scans were performed without adverse events. The average ECA supply was 54% (range 31.5-91%). The mean embolized tumor volume was 56.5% (range 25-94%). Relative PBV values decreased from 5.75 ± 1.55 before embolization to 2.43 ± 1.70 post-embolization. In one patient, embolization was not performed because of being considered not beneficial for the resection. Angiographic FD CTP imaging of the brain tumor allows 3D identification and quantification of individual tumor feeder arteries. Furthermore, the technique enables monitoring of the efficacy of pre-operative endovascular tumor embolization.

Meningoencephalitis with Streptococcus equi Subspecies equi Leading to a Dural Arteriovenous Fistula.

Invasive infection with Lancefield group C streptococci in humans is extremely rare, with the vast majority of clinical isolates belonging to Streptococcus dysgalactiae subsp. equisimilis. We report a case of meningoencephalitis in a 69-year-old man caused by Streptococcus equi subsp. equi, a microbe that causes strangles in Equus caballus (i.e., the horse). This is only the fourth infection with this subtype of the central nervous system (CNS) reported in humans. The invasiveness of these bacteria, known to be capable of releasing strongly immunogenic exotoxins, is illustrated by white matter lesions that are present in the acute phase. This patient initially recovered well after treatment with antibiotics and glucocorticoids. However, the patient was readmitted 5 months later with multiple intraparenchymatous cerebral haemorrhages. Cerebral angiography confirmed the presence of a suspected superficial dural arteriovenous fistula (DAVF), which is seldom reported after CNS infection. The invasiveness of these bacteria was illustrated by white matter lesions present in the acute phase and the occurrence of a de novo dural arteriovenous fistula in the follow-up period.

Vessel territory mapping after cerebral revascularization surgery using selective angiographic flat detector perfusion imaging.

The technical feasibility and diagnostic potential of angiographic flat-detector perfusion imaging technique, combining digital subtraction angiography with a flat-detector computed tomography steady-state perfusion imaging, was explored in patients treated with direct or indirect revascularization surgery. This short communication is about an imaging modality with great potential for evaluation, comparison and grading of vascular perfusion territory areas and anatomical location selectively perfused by direct and indirect cerebral bypasses.

Multicenter, retrospective analysis of endovascular treatment for acute ischemic stroke in nonagenarians.

BACKGROUND: With the increasing age of acute stroke patients being admitted to hospitals, more data are needed on indications, complications and outcome of endovascular treatment (EVT) in the very elderly. METHODS: Retrospective observational study with data collection from Belgian, Swiss, Canadian comprehensive stroke centers and Swedish EVT National database. All patients with acute ischemic stroke were eligible if aged older than or ≥90 years and treated with EVT ± pretreatment with intravenous thrombolysis (IVT). Safety assessment comprised presence of periprocedural complications, hemorrhagic transformation or other adverse events (<7days). Efficacy and outcome measures were successful recanalization (modified Treatment In Cerebral Infarction (mTICI) score ≥2b), favorable clinical outcome (modified Rankin Score (mRS) 0-2) and 3-months mortality. RESULTS: Inclusion of 112 nonagenarians (mean age 93.3 ± 2.5 years; 76.8% women; pre-mRS ≤2 in 69.4%). Pretreatment with IVT was performed in 54.7%. In 74.6% successful recanalization (mTICI ≥2b) was achieved. Favorable outcome (mRS ≤2) was seen in 16.4% and 3-months mortality was 62.3%. Multivariate logistic regression analysis showed younger age (odds ratio [OR] 2.99; 1.29-6.95; P = .011) and lower prestroke mRS (OR 13.46; 2.32-78.30; P = .004) as significant predictors for good clinical outcome at 90 days. CONCLUSIONS: Our observational study on EVT in nonagenarians demonstrates the need for careful patient selection. A substantial proportion of nonagenarians shows an unfavorable clinical outcome and high mortality, despite acceptable recanalization rates. A high prestroke disability (mRS) and advancing age predict an unfavorable outcome. Treatment decisions should be made on case-by-case evaluation, keeping in mind limited chances of favorable outcome and high risk of mortality.

Geniculate Artery Embolization in Patients With Recurrent Hemarthrosis After Knee Arthroplasty: A Retrospective Study.

BACKGROUND: Recurrent hemarthrosis after knee arthroplasty is an uncommon and disabling complication of this frequently performed procedure. Selective endovascular embolization of the geniculate arteries is one of the therapeutic options to manage this complication. The purpose of this study is to analyze the effectiveness of this treatment in patients suffering from recurrent hemarthrosis after knee arthroplasty. METHODS: We performed a retrospective study of 31 patients (39 embolization procedures) with recurrent hemarthrosis after knee arthroplasty. There were 17 men and 14 women with a median age of 67 years (range 48-90). All patients were referred for geniculate artery embolization between January 2007 and November 2016. RESULTS: Twenty-seven procedures were executed on the right side and 12 on the left side. Total knee arthroplasty was performed on 29 patients, only 2 patients underwent unicompartmental knee arthroplasty. Embolization of the superior geniculate arteries was achieved in all patients. In 12 of 39 procedures (31%), at least 1 of the inferior geniculate arteries could not be catheterized, therefore embolization was achieved through collaterals. Symptomatic improvement was observed in 26 of 31 patients (84%). Discomfort or mild postprocedural pain was observed in most patients, needing only minor pain medication, mostly resolving within 24 hours. Two patients presented with a severe complication: a 48-year-old male patient developed septic arthritis and an 85-year-old hypertensive female patient treated with anticoagulants showed aseptic necrosis of the femoral condyles. CONCLUSION: Embolization of geniculate arteries is a safe and effective treatment in recurrent hemarthrosis post knee arthroplasty. Clinical improvement was seen in most patients.

Current concepts in imaging and endovascular treatment of acute ischemic stroke: implications for the clinician.

During the last decade, the management of acute ischemic stroke has changed dramatically, from an expectant bedside "wait and see" attitude towards active treatment, thanks to the continuous improvement of new therapeutic options. In addition to the use of intravenous (IV) thrombolysis in emergent large vessel occlusion (ELVO), endovascular therapy (EVT) has proven to be very efficient in selected acute stroke patients. The indications for EVT have progressed from the era of thrombolysis to individual patient profiling. Recently, several indication parameters, e.g., "treatment time window" or "more distal vessel occlusion," are under debate for adjustment. In this article, we review the imaging strategies in acute stroke and discuss several EVT indication dogmas, which are subject to change.

Measuring future liver remnant function prior to hepatectomy may guide the indication for portal vein occlusion and avoid posthepatectomy liver failure: a prospective interventional study.

BACKGROUND: Estimation of the future liver remnant function (eFLRF) can avoid post-hepatectomy liver failure (PHLF). In a previous study, a cutoff value of 2.3%/min/m2 for eFLRF was a better predictor of PHLF than future liver remnant volume (FLRV%). In this prospective interventional study, investigating a management strategy aimed at avoiding PHLF, this cutoff value was the sole criterion assessing eligibility for hepatectomy, with or without portal vein occlusion (PVO). METHODS: In 100 consecutive patients, eFLRF was determined using the formula: eFLRF = FLRV% × total liver function (TLF). Group 1 (eFLRF >2.3%/min/m2) underwent hepatectomy without preoperative intervention. Group 2 (eFLRF <2.3%/min/m2) underwent PVO and re-evaluation of eFLRF at 4-6 weeks. Hepatectomy was performed if eFLRF had increased to >2.3%/min/m2, but was considered contraindicated if the value remained lower. RESULTS: In group 1 (n = 93), 1 patient developed grade B PHLF. In group 2 (n = 7) no PHLF was recorded. Postoperative recovery of TLF in patients with preoperative eFLRF <2.3%/min/m2 occurred more rapidly when PVO had been performed. CONCLUSION: A predefined cutoff for preoperatively calculated eFLRF can be used as a tool for selecting patients prior to hepatectomy, with or without PVO, thus avoiding PHLF and PHLF-related mortality.

U-Shape Kissing Chimney Thoracic Endovascular Aneurysm Repair for a Traumatic Arch Rupture in a Polytraumatized Patient.

An 18-year-old male patient was admitted to our hospital because of a high impact trauma. A computed tomography scan showed massive mediastinal bleeding due to a posteriorly located rupture of the aortic arch with formation of a pseudoaneurysm. Although urgent repair was indicated, open cardiac surgery was not feasible, as this would involve full heparinization in a patient with subarachnoid bleeding. The chosen solution was to perform a percutaneous thoracic endovascular aneurysm repair (TEVAR) and a kissing chimney procedure using a U-shape configuration.

Brain stones revisited-between a rock and a hard place.

OBJECTIVES AND METHODS: Large intracranial calcifications are occasionally encountered in routine computed tomography (CT) scans of the brain. These calcifications, also known as "brain stones", can be classified according to location and aetiology. Combining imaging findings with relevant clinical history and physical examination can help narrow down the differential diagnosis and may allow confident diagnosis in certain situations. RESULTS: This article provides a pictorial review illustrating various clinical entities resulting in brain stones. DISCUSSION: Based on location, brain stones can be classified as extra- or intra-axial. Extra-axial brain stones comprise tumours and exaggerated physiological calcifications. Intra-axial brain stones can further be classified according to aetiology, namely neoplastic, vascular, infectious, congenital and endocrine/metabolic. Imaging findings combined with essential clinical information can help in narrowing the differential diagnosis, determining disease state and evaluating effect of therapy. TEACHING POINTS: • Based on location, brain stones can be either extra- or intra-axial. • Extra-axial brain stones comprise tumours and exaggerated physiological calcifications. • Intra-axial aetiologies include neoplastic, vascular, infectious, congenital and endocrine/metabolic. • CT scan is the mainstay in identifying and characterising brain stones. • Certain MRI sequences (gradient echo T2* and susceptibility-weighted imaging) are considered adjunctive.

Perforated oculomotor nerve after endovascular coiling: complete regeneration after microsurgical repair. case report.

BACKGROUND AND IMPORTANCE: We describe a patient who developed complete right oculomotor nerve palsy after endovascular coiling for a ruptured posterior communicating artery aneurysm caused by migration of the coils outside the aneurysm. CLINICAL PRESENTATION: A 50-year-old woman was admitted with an acute subarachnoid hemorrhage. She underwent, on the day of admission, endovascular coiling of a ruptured posterior communicating artery aneurysm. Four hours postcoiling, complete right oculomotor nerve palsy developed because of extrusion of the coils outside the aneurysm. The patient recovered completely after surgical exploration with removal of the migrated coils and microsurgical repair of the oculomotor nerve. CONCLUSION: This report illustrates that oculomotor nerve palsy is a rare complication after coiling of a posterior communicating artery aneurysm, and it should serve as a reminder to encourage neurovascular teams to consider surgical exploration in cases of third nerve palsy after endovascular coiling.