Reconstruction of the sphenoid sinus erosion or dehiscence after treatment of unruptured intracavernous aneurysms with flow diverter stents.

BACKGROUND: Intracavernous carotid aneurysms (ICCAs) are rare, frequently asymptomatic, with a low rupture risk, which, however, can lead to life-threatening epistaxis. The aim of this study was to assess the effect of the treatment of asymptomatic ICCAs with flow diverters (FD) on sphenoid bone erosion or dehiscence in a selected cohort of patients. METHODS: We retrospectively reviewed all asymptomatic ICCAs with sphenoid bone erosion or dehiscence detected on cone beam CT (CBCT) and treated with FD between December 2018 and December 2022. Patients were followed-up with CBCT and bone reconstruction was blindly evaluated by two interventional neuroradiologists and classified as unchanged, partial, or complete. RESULTS: A total of 10 patients (women: 90%, mean age 58 years) treated with an FD for an asymptomatic ICCA with associated sphenoid bone erosion or dehiscence were included in this cohort. Sphenoid bone erosion was present in seven patients and dehiscence was observed in the remaining three. After treatment with FD, complete reconstruction of the sphenoid sinus wall occurred in seven cases, and partial reconstruction in two cases. Sphenoid bone erosion remained unchanged after treatment in only one patient. CONCLUSIONS: The decision to treat asymptomatic and unruptured ICCAs remains challenging due to their benign natural history and low hemorrhagic risk. The presence of sphenoid sinus erosion or dehiscence should not be overlooked since it could be considered as an indication for prophylactic treatment of life-threatening epistaxis. The mechanisms of bone erosion by the aneurysm and of reconstruction after treatment are still to be fully elucidated.

Angiographic collateral venous phase: a novel landmark for leptomeningeal collaterals evaluation in acute ischemic stroke.

BACKGROUND: Although recanalization rates constantly increase (>80%), a favorable clinical outcome is achieved in only 45-55% of patients undergoing mechanical thrombectomy (MT) for anterior circulation stroke. Collateral circulation seems to play a major role in determining this discrepancy. The aim of the study was to investigate a novel angiographic landmark assessing the collateral venous phase (CVP) compared with the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) score, based on the arterial collateral assessment. METHODS: Two hundred patients with anterior circulation stroke treated by MT between 2016 and 2021 were included. The ASITN/SIR score and the presence of CVP were blindly evaluated by expert neuroradiologists. Three subanalyses were performed comparing patients with good versus poor collaterals, CVP presence versus absence, and a composite analysis including both ASITN/SIR and CVP grading results. RESULTS: Good collateral circulation (ASITN >2) was observed in 113 patients (56.5%) whereas CVP was present in 90 patients (45%) and mostly in patients with good collaterals. Favorable clinical and neuroradiological outcomes were more likely observed in patients with both good collaterals and the presence of CVP than in those with good collaterals and absence of CVP (modified Rankin Scale score 0-2: 77.3% vs 7.9%, p<0.0001; mortality: 9.3% vs 26.3%, p=0.02; 24-hour Alberta Stroke Program Early CT Score: 8 vs 6, p<0.0001), while ASITN/SIR score alone was not significantly associated with clinical outcomes. CONCLUSIONS: The presence of CVP improves the angiographic assessment of collateral circulation. CVP could be proposed as a new imaging landmark to better understand the functionality of collaterals.

Rupture of a detachable-tip microcatheter away from the detachment zone during Onyx 18 embolization of an arteriovenous malformation and management of the complication.

Leakage of liquid embolic material is a rare but dreaded complication during embolization of an arteriovenous malformation (AVM). We describe the rupture of a microcatheter away from the detachment site and the successful removal of the cast of Onyx 18 in the carotid artery by aspiration. A young adult patient diagnosed with a right temporal unruptured AVM underwent endovascular embolization using Onyx 18. The AVM was approached using an Apollo microcatheter. After 4 min of Onyx 18 injection, leakage of Onyx 18 in the petrous segment of the internal carotid artery was noticed while the distal tip of the microcatheter remained patent. The plug of Onyx was successfully removed using an aspiration technique via the Envoy DA catheter. Analysis of the microcatheter confirmed that the rupture occurred away from the detachment site. However, no definite cause for the rupture has been identified.

Mechanical Thrombectomy in Distal Residual Occlusions of the Middle Cerebral Artery after Large Vessel Recanalization in Acute Stroke: 2b or not 2b? A Pragmatic Approach in Real-Life Scenarios.

BACKGROUND /OBJECTIVE: Recent studies have suggested that a recanalization grade of modified Thrombolysis in Cerebral Infarction (mTICI) score ≥2c is strongly related with good clinical outcome rather than the current therapeutic angiography target ≥2b. To achieve better recanalization, additional further maneuvers on distal residual vessel occlusion (RVO) may be required. The aim of this study was to evaluate the safety and efficacy of rescue treatment in RVOs after recanalization of large vessel occlusions in the anterior circulation. METHODS: A single-center retrospective review of a prospectively maintained stroke databank was performed. Patients presenting with RVOs after mechanical thrombectomy on the M1/internal carotid artery terminus were included and further divided into treated and untreated groups: the former underwent additional maneuvers on RVOs, whereas the latter did not. Baseline and posttreatment clinical, radiologic, and angiographic data were compared between the 2 groups. End points included good functional outcome (modified Rankin Scale [mRS] score ≤2) rates of hemorrhagic transformations, neurologic deterioration and mortality. RESULTS: RVOs were observed in 183/488 patients (37.5%). 74/183 (40.4%) underwent rescue treatment, showing a better outcome in terms of median 24 hours National Institutes of Health Stroke Scale score (13 vs. 18; P < 0001), 24 hours Alberta Stroke Programme Early CT Score (6 vs. 5; P < 0.001) and 3 months mRS score 0-2 (47.3% vs. 33.1%; P = 0.06). Recanalization of the superior (frontal) branch of the middle cerebral artery was particularly critical in terms of outcome. Hemorrhagic transformation was higher in the untreated group (53.6% vs. 66.6%; P = 0.1) as well as symptomatic intracranial hemorrhage (13.1% vs. 29.4%; P = 0.01). Neurologic deterioration occurred more often among untreated patients (16.2% vs. 25.7%; P = 0.1). Three complications (1.3%) occurred during rescue treatment. CONCLUSIONS: When feasible, improving mTICI score 2a-2b recanalization to mTICI 2c/3 is safe and associated with a better clinical outcome, particularly for residual occlusions involving the superior branch of bifurcation.

Concomitant conus medullaris arteriovenous shunts and sacral dural arteriovenous fistulas: pathophysiological links related to the venous drainage of the lesions in a series of five cases.

BACKGROUND: Spinal cord arteriovenous shunts (scAVSs) are a group of lesions located in the spinal cord itself or in the surrounding structures. The most common scAVSs are spinal dural arteriovenous fistulas (sDAVFs), which are acquired lesions. The pathogenesis of sDAVFs involves thrombosis and venous hypertension as trigger factors. Intradural scAVSs such as spinal cord arteriovenous nidus type malformations (AVMs) and pial arteriovenous fistulas are less common than sDAVFs and are considered to have a so-called 'congenital' origin. The association between different concomitant scAVSs is very rare and the association of sDAVFs with intradural scAVSs has been described in only a few case reports. METHODS: We describe a case series of five patients presenting with a conus medullaris AVS associated with a lower lumbar or sacral DAVF. RESULTS: Three of our patients were <30 years old at presentation. In four of these five cases the intradural scAVS drained caudally, engorging the epidural plexus in the same location as the sDAVF. In only one case, who presented with thrombosis of the drainage of the main compartment of a conus medullaris pial AVF, was the location of the DAVF opposite to the location of the residual drainage. CONCLUSION: We discuss the pathophysiological link between scAVS and sDAVF on the basis of the rarity of the DAVF, the uncommon association between scAVS and sDAVF, the presence of sDAVF in young patients, and the venous hypertension created by the venous drainage towards the sacral area responsible for angiogenesis creating the dural shunt.