Abstract Number ‐ 84: Importance of Early Detection and Treatment of Traumatic Intracranial Pseudoaneurysms Prior to Decompressive Hemicraniectomy

Introduction Intracranial pseudoaneurysms are rare lesions that represent less than 1% of all intracranial aneurysms.1They typically occur due to disruption of the arterial wall layers and subsequent extramural/extraluminal hematoma formation following traumatic brain injury, resulting in a higher risk of rebleeding than that of saccular cerebral aneurysms.2Pseudoaneurysms have higher incidence in children and young adults, and given their association with high morbidity and mortality, early detection and management is essential.2‐4The purpose of this study is to highlight the importance of early recognition and management of traumatic pseudoaneurysms prior to decompressive hemicraniectomy. Methods This is a case report of a six‐year‐old previously healthy male who presented as a level 1 trauma alert after sustaining a gunshot wound to the face while manipulating an unsecured weapon at his residence. Upon arrival, lack of airway protection requiring intubation, entry wound to the anterior forehead, and diffuse forehead and periorbital edema were observed. CT head demonstrated multicompartmental hemorrhage with 6mm right to left midline shift and diffuse cerebral edema. CTA head and neck noted possible thrombosed right anterior cerebral artery (ACA) pseudoaneurysm in the right frontoparietal region (Figure 1‐A). Prior to decompressive hemicraniectomy, neuro‐endovascular consultation was obtained, and emergent cerebral angiogram was recommended. This case highlights the findings demonstrated on cerebral angiography, the technique by which the pseudoaneurysm was detected and secured, and the importance of doing so prior to further neurosurgical interventions. Results The patient was taken for diagnostic cerebral angiogram via femoral artery access. Initial angiographic run of the right internal carotid artery demonstrated distal right pericallosal artery slowing without clear evidence of underlying vascular injuries. Given concern for underlying thrombosed pseudoaneurysm and its parent branch, selective catheterization of the proximal pericallosal artery off the distal ACA was performed. Gentle angiographic run was obtained via microcatheter that demonstrated superior parietal artery pseudoaneurysm without active extravasation (Figure 1‐B). The microcatheter was advanced and placed in the proximal portion of the pseudoaneurysm sac and five platinum coils were deployed to fully obliterate the pseudoaneurysm and its parent feeder while protecting the adjacent paracentral artery (Figure 1‐C, 1‐D). Following completion of the endovascular procedure, the patient was transferred to the operative room for right decompressive hemicraniectomy and clot evacuation, which were completed successfully. Conclusions Prompt detection and securement of traumatic intracranial pseudoaneurysms are essential prior to invasive neurosurgical interventions to reduce risk of recurrent bleeding. Selective angiographic evaluation of the parent injured vessel(s) is crucial for optimal assessment of the underlying lesion. Neuro‐endovascular interventions including coil embolization, stenting, flow‐diverter implantation, and parental artery occlusion have emerged as alternatives to conventional neurosurgical management.2 This case highlights the successful early detection and treatment of a traumatic intracranial pseudoaneurysm with coil embolization followed by uncomplicated decompressive hemicraniectomy

Abstract Number ‐ 90: Bailout Technique for Entangled Stentriever and Carotid Stent during Tandem Large Vessel Occlusion Endovascular Therapy

Introduction Tandem occlusions represent 10–20% of all acute ischemic stroke patients.1 Endovascular Thrombectomy (EVT) for this subset of patients is more challenging given the proximal underlying steno occlusive disease. Emergent carotid artery stenting could achieve a considerably high chance of reperfusion and functional independence.2 Methods This is a case report of a 73‐year‐old woman who presented with left MCA syndrome‐NIHSS 13 found to have left ICA/MCA tandem occlusions. EVT was pursued, initial angiographic run of the left common carotid artery demonstrated severe stenosis at the origin of left cervical ICA which harbors a mid‐cervical ICA loop and proximal left MCA occlusion. Following our retrograde revascularization approach, an intracranial pass using an embotrap 5mm x 37 mm stent retriever (SR) was attempted however given proximal cervical ICA tortuosity and underlying proximal stenosis, the stability of triaxial system prevented optimal placement of the SR and achieving intracranial reperfusion. An antegrade revascularization approach was then pursued with uneventful cervical ICA angioplasty followed by extracranial carotid closed cell Xact stent placement. A stable triaxial system was navigated through the stented cervical ICA. An ideal SR pass was performed. Upon retrieving the clot‐incorporated SR with the intention to fully retrieve the SR into the locally placed aspiration catheter (AC) in the supraclinoid ICA under continuous aspiration, the triaxial system collapsed into the distal CCA, likely due to the mid cervical ICA loop, leading to entanglement of the proximal end of SR and distal ICA stent (Figure1‐A). Large thrombus was recovered from the AC aspirate. Results Numerous attempts to disentangle the SR from the ICA stent including attempts to re‐sheath the SR with different size microcatheters and guide catheters were unsuccessful. The cervical ICA lumen remained patent without evidence of dissection or residual thrombus however, the presence of SR pusher‐wire would preclude safe termination of the procedure. Surgical bailout with emergent carotid endarterectomy and removal of the stent/SR metal mesh was considered.3,4 However, given the high surgical risk with recent intravenous load of antithrombotics for emergent stent placement, this option was deemed as a last resort. We decided to attempt safe separation of the SR from its pusher wire and leave behind the patent ICA stent/SR in place. A gradual pulling pressure was applied to the SR wire while maintaining adjacent microwire access and fully inflated Viatrac 5mm x 30 mm extracranial balloon over the entangled portion to ensure continuous vascular access (Figure1‐B). The SR wire was then separated from the SR and fully retracted outside the body (Figure1‐C). Delayed angiographic runs continued to demonstrate full patency of the ICA lumen (Figure1‐D). No residual dissection, spasm or thrombus noted. Patient was discharged home with NIHSS of 3. Conclusions Exposure to EVT technical complications and bailout techniques are of utmost importance