Use of transcarotid artery revascularization for mechanical thrombectomy and treatment of symptomatic high-grade carotid artery stenosis associated with free-floating thrombus: illustrative case.

BACKGROUND: Patients with symptomatic high-grade stenosis of the internal carotid artery (ICA) associated with a free-floating thrombus (FFT) present a significant clinical challenge. In general, for patients with moderate to severe symptomatic ICA stenosis, carotid revascularization is recommended within 2 weeks of symptom onset; however, some physicians suggest that revascularization should be delayed in cases with FFT because some data suggest that early surgery with carotid endarterectomy or carotid stent poses a higher risk for stroke. Likewise, delayed revascularization with anticoagulation may increase risk of recurrent stroke. Few reports on the management of FTT included the use of a transcarotid artery revascularization (TCAR) approach for carotid revascularization with mechanical aspiration thrombectomy. OBSERVATIONS: This report described the use of TCAR for direct mechanical thrombectomy and carotid stent placement for a patient with 80% right ICA stenosis along with a large FFT extending into the bulb and the external carotid artery. LESSONS: The TCAR approach for mechanical thrombectomy and carotid stenting is a safe alternative for early revascularization with low periprocedural stroke risks.

Middle meningeal artery embolization for chronic subdural hematoma in cancer patients with refractory thrombocytopenia.

OBJECTIVE: Surgical evacuation of chronic subdural hematoma (SDH) in cancer patients is often contraindicated owing to refractory thrombocytopenia. Middle meningeal artery embolization (MMAE) recently emerged as a potential alternative to surgical evacuation for patients with chronic SDH. The goal of this study was to evaluate the safety and efficacy of MMAE for chronic SDH in cancer patients with refractory thrombocytopenia. METHODS: A multiinstitutional registry was reviewed for clinical and radiographic outcomes of cancer patients with transfusion-refractory thrombocytopenia and baseline platelet count < 75 K/µl, who underwent MMAE for chronic SDH. RESULTS: MMAE was performed on a total of 31 SDHs in 22 patients, with a mean ± SD (range) platelet count of 42.1 ± 18.3 (9-74) K/µl. At the longest follow-up, 24 SDHs (77%) had reduced in size, with 15 (48%) showing > 50% reduction. Two patients required surgical evacuation after MMAE. There was only 1 procedural complication; however, 16 patients (73%) ultimately died of cancer-related complications. Median survival was significantly longer in the 16 patients with improved SDH than the 6 patients with worsened SDH after MMAE (185 vs 24 days, p = 0.029). Length of procedure, technical success rate, SDH size reduction, and complication rate were not significantly differ between patients who underwent transfemoral and transradial approaches. CONCLUSIONS: Transfemoral or transradial MMAE is a potential therapeutic option for thrombocytopenic cancer patients with SDH. However, treatment benefit may be marginal for patients with high disease burden and limited life expectancy. A prospective trial is warranted to address these questions.

Endovascular embolization versus surgical clipping in a single surgeon series of basilar artery aneurysms: a complementary approach in the endovascular era.

BACKGROUND: Currently, most basilar artery aneurysms (BAAs) are treated endovascularly. Surgery remains an appropriate therapy for a subset of all intracranial aneurysms. Whether open microsurgery would be required or utilized, and to what extent, for BAAs treated by a surgeon who performs both endovascular and open procedures has not been reported. METHODS: Retrospective analysis of prospectively maintained, single-surgeon series of BAAs treated with endovascular or open surgery from the first 5 years of practice. RESULTS: Forty-two procedures were performed in 34 patients to treat BAAs-including aneurysms arising from basilar artery apex, trunk, and perforators. Unruptured BAAs accounted for 35/42 cases (83.3%), and the mean aneurysm diameter was 8.4 ± 5.4 mm. Endovascular coiling-including stent-assisted coiling-accounted for 26/42 (61.9%) treatments and led to complete obliteration in 76.9% of cases. Four patients in the endovascular cohort required re-treatment. Surgical clip reconstruction accounted for 16/42 (38.1%) treatments and led to complete obliteration in 88.5% of cases. Good neurologic outcome (mRS ≤ 2) was achieved in 88.5% and 75.0% of patients in endovascular and open surgical cohorts, respectively (p = 0.40). Univariate logistic regression analysis demonstrated that advanced age (OR 1.11[95% CI 1.01-1.23]) or peri-procedural adverse event (OR 85.0 [95% CI 6.5-118.9]), but not treatment modality (OR 0.39[95% CI 0.08-2.04]), was the predictor of poor neurologic outcome. CONCLUSIONS: Complementary implementation of both endovascular and open surgery facilitates individualized treatment planning of BAAs. By leveraging strengths of both techniques, equivalent clinical outcomes and technical proficiency may be achieved with both modalities.

Suboccipital craniectomy with bilateral cerebellomedullary fissure dissection for resection of a ruptured tonsillar/vermian AVM occupying the roof of the fourth ventricle in a pregnant patient.

Posterior fossa arteriovenous malformations (AVMs) in pregnant patients can present unique considerations for surgical treatment, including positioning to minimize pressure on the fetus, minimization of radiation exposure, and ethical considerations regarding emergency surgery. This video outlines surgical treatment of a ruptured tonsillar/vermian AVM performed in a staged fashion after emergent suboccipital craniotomy with posterior fossa decompression in the setting of a life-threatening infratentorial hemorrhage. Later, bilateral cerebellomedullary fissure dissection, exposure and dissection of the tela choroidea and inferior medullary velum, and disconnection of arterial feeders from the posterior inferior cerebellar artery (PICA) allowed resection of this AVM occupying the roof of the fourth ventricle. This study was approved by the UCSF Human Research Protection Program IRB no. 18-26938. The video can be found here: https://youtu.be/rTYUGanopUE.

Controversies and Advances in Adult Intracranial Bypass Surgery in 2020.

Cerebral revascularization utilizing a variety of bypass techniques can provide either flow augmentation or flow replacement in the treatment of a range of intracranial pathologies, including moyamoya disease, intracranial atherosclerotic disease, and complex aneurysms that are not amenable to endovascular or simple surgical techniques. Though once routine, the publication of high-quality prospective evidence, along with the development of flow-diverting stents, has limited the indications for extracranial-to-intracranial (EC-IC) bypass. Nevertheless, advances in imaging, assessment of cerebral hemodynamics, and surgical technique have changed the risk-benefit calculus for EC-IC bypass. New variations of revascularization surgery involving multiple anastomoses, flow preserving solutions, IC-IC constructs, and posterior circulation bypasses have been pioneered for otherwise difficult to treat pathology including giant aneurysms, dolichoectasia, and medically refractory intracranial atherosclerosis. This review provides a practical update on recent advances in adult intracranial bypass surgery.

How I do it: superficial temporal artery-middle cerebral artery bypass for flow augmentation and replacement.

BACKGROUND: The superficial temporal artery-middle cerebral artery (STA-MCA) bypass augments blood flow in patients with cerebral ischemia or replaces flow in patients with complex aneurysms or skull base tumors requiring vessel sacrifice. METHOD: We provide a description of the STA-MCA bypass with figures and video to illustrate the procedure. CONCLUSION: The STA-MCA end-to-side anastomosis is a foundational skill for the cerebrovascular surgeon and a building block for more complex bypasses.

Spontaneous Perforation of Anterior Choroidal Artery with Resultant Pseudoaneurysm Formation: Unusual Cause of Subarachnoid Hemorrhage.

BACKGROUND: Subarachnoid hemorrhage resulting from spontaneous perforation of a small intracranial vessel, with resultant pseudoaneurysm formation, has not been widely reported in the literature. CASE DESCRIPTION: We present the case of a 71-year-old patient with rupture of a small aneurysm of a duplicated left anterior choroidal artery causing an acute third nerve palsy. The aneurysm was not able to be treated endovascularly without sacrifice of the parent vessel. At surgery, a pseudoaneurysm was seen completely separate from the parent vessel, which was actively bleeding through a hole in the vessel. The pseudoaneurysm was indenting the oculomotor nerve. After confirmation of adequate collateral flow, the abnormal segment of vessel was trapped and the pseudoaneurysm removed with surrounding clot. The patient's cranial nerve palsy resolved. CONCLUSIONS: This case illustrates an unusual sequela of subarachnoid hemorrhage presenting a unique challenge in surgical management.

Enhanced recovery after surgery in intramedullary and extramedullary spinal cord lesions: perioperative considerations and recommendations.

Enhanced recovery after surgery (ERAS) is an evidence-based approach developed to ameliorate the patient recovery process following surgical procedures. Employing a multimodal, multidisciplinary approach, ERAS implements strategies and treatment paradigms that have been shown to improve patient outcomes, reduce hospital length of stay, and ultimately reduce healthcare costs. With a substantial body of the literature supporting the implementation of ERAS in other surgical specialties, ERAS has only recently made its foray into spine surgery. Despite this, current studies are limited to spinal deformity and degenerative disease, with limited data regarding spinal cord surgery. This is due in part to the complex nature and rarity of spinal cord lesions, making the establishment of a formal ERAS protocol difficult. In developing an ERAS protocol, there must be a consensus on what factors are important to consider and implement. To address this, we reviewed the most recent advances in intramedullary and extramedullary spinal cord surgery in order to identify elements that influence patient outcomes. Using this information, the authors provide evidence-based recommendations with the intent of introducing a framework for future ERAS protocols with respect to treating spinal cord lesions.

Development of an Intracranial Dural Arteriovenous Fistula after Venous Sinus Stenting for Idiopathic Intracranial Hypertension.

We report a case in which an intracranial dural arteriovenous fistula (DAVF) developed after endovascular treatment of a patient with idiopathic intracranial hypertension with venous sinus stenting (VSS). The pathogenesis may involve hemodynamic alterations secondary to increased poststenting venous sinus pressure, which may cause new arterial ingrowth into the fistulous sinus wall without capillary interposition. Despite administration of dual antiplatelet therapy, there may also be subclinical cortical vein thrombosis that contributed to DAVF formation. In addition to the aforementioned mechanisms, increased inflammation induced by VSS may upregulate vascular endothelial growth factor and platelet-derived growth factor expression and also promote DAVF pathogenesis. Since VSS has been used to obliterate DAVFs, DAVF formation after VSS may seem counterintuitive. Previous stents have generally been closed cell, stainless steel designs used to maximize radial compression of the fistulous sinus wall. In contrast, our patient's stent was an open cell, self-expandable nitinol design (Protégé Everflex). Neurointerventionalists should be aware of this potential, although rare complication of DAVF formation after VSS.

Posterior circulation perforator aneurysms: a proposed management algorithm.

INTRODUCTION: Subarachnoid hemorrhage (SAH) from posterior circulation perforator aneurysms (PCPAs) is rare and its natural history is unknown. Diagnosis may be difficult, acute management is poorly defined, and long-term recurrent SAH rates and clinical outcome data are lacking. METHODS: We searched our institution's records for cases of PCPA rupture and analyzed patient demographics, Hunt and Hess (HH) grades, diagnostic imaging, management, and clinical outcomes. We conducted telephone interviews to calculate modified Rankin Scale (mRS) scores. RESULTS: We identified 9 patients (6 male, 3 female) with a ruptured PCPA who presented to the University of Virginia Health System (Charlottesville, VA, USA) between 2010 and 2016. Median and mean ages were 62 and 63 years, respectively. Median HH grade was 3. Seven of nine (78%) PCPAs were angiographically occult on initial imaging and median time to diagnosis was 5 days. Three conservatively managed patients had a mean mRS score of 0.67 (range 0-1) at mean follow-up of 35.3 months. Antifibrinolytic therapy was administered to all conservatively managed patients without thrombotic complication. Six patients receiving endovascular treatment had a mean mRS score of 2.67 (range 0-6) at mean follow-up of 49.2 months. No cases of recurrent SAH were seen in the study. CONCLUSIONS: The rarity of PCPA has precluded long-term clinical follow-up until now. Our experience suggests low recurrent SAH rates. Until further studies are performed, conservative management, possibly combined with antifibrinolytic therapy, may be a viable treatment with acceptable long-term outcome.

A pilot study and novel angiographic classification for superior sagittal sinus stenting in patients with non-thrombotic intracranial venous occlusive disease.

OBJECTIVE: Safety and efficacy of superior sagittal sinus (SSS) stenting for non-thrombotic intracranial venous occlusive disease (VOD) is unknown. The aim of this retrospective cohort study is to evaluate outcomes after SSS stenting. METHODS: We evaluated an institutional database to identify patients who underwent SSS stenting. Radiographic and clinical outcomes were analyzed and a novel angiographic classification of the SSS was proposed. RESULTS: We identified 19 patients; 42% developed SSS stenosis after transverse sinus stenting. Pre-stent maximum mean venous pressure (MVP) in the SSS of 16.2 mm Hg decreased to 13.1 mm Hg after stenting (p=0.037). Preoperative trans-stenosis pressure gradient of 4.2 mm Hg decreased to 1.5 mm Hg after stenting (p<0.001). No intraprocedural complication or junctional SSS stenosis distal to the stent construct was noted. Improvement in headache, tinnitus, and visual obscurations was reported by 66.7%, 63.6%, and 50% of affected patients, respectively, at mean follow-up of 5.2 months. We divided the SSS into four anatomically equal segments, numbered S1-S4, from the torcula to frontal pole. SSS stenosis typically occurs in the S1 segment, and the anterior extent of SSS stents was deployed at the S1-S2 junction in all but one case. CONCLUSIONS: SSS stenting is reasonably safe, may improve clinical symptoms, and significantly reduces maximum MVP and trans-stenosis pressure gradients in patients with VOD with SSS stenosis. The S1 segment is most commonly stenotic, and minimum pressure gradients for symptomatic SSS stenosis may be lower than for transverse or sigmoid stenosis. Additional studies and follow-up are necessary to better elucidate appropriate clinical indications and long-term efficacy of SSS stenting.

Endovascular treatment for cerebral vasospasm following aneurysmal subarachnoid hemorrhage: predictors of outcome and retreatment.

OBJECTIVE: Although endovascular therapy has been widely adopted for the treatment of cerebral vasospasm after aneurysmal subarachnoid hemorrhage (aSAH), its effect on clinical outcomes remains incompletely understood. The aims of this retrospective cohort study are to evaluate the outcomes of endovascular intervention for post-aSAH vasospasm and identify predictors of functional independence at discharge and repeat endovascular vasospasm treatment. METHODS: We assessed the baseline and outcomes data for patients with aSAH who underwent endovascular vasospasm treatment at our institution, including intra-arterial (IA) vasodilator infusion and angioplasty. Statistical analyses were performed to determine factors associated with good outcome at discharge (modified Rankin Scale 0-2) and repeat endovascular vasospasm treatment. RESULTS: The study cohort comprised 159 patients with a mean age of 52 years. Good outcome was achieved in 17% of patients at discharge (26/150 patients), with an in-hospital mortality rate of 22% (33/150 patients). In the multivariate analysis, age (OR 0.895; p=0.009) and positive smoking status (OR 0.206; p=0.040) were negative independent predictors of good outcome. Endovascular retreatment was performed in 34% (53/156 patients). In the multivariate analysis, older age (OR 0.950; p=0.004), symptomatic vasospasm (OR 0.441; p=0.046), initial treatment with angioplasty alone (OR 0.096; p=0.039), and initial treatment with combined IA vasodilator infusion and angioplasty (OR 0.342; p=0.026) were negative independent predictors of retreatment. CONCLUSION: We found a modest rate of functional independence at discharge in patients with aSAH who underwent endovascular vasospasm treatment. Older patients and smokers had worse functional outcomes at discharge. Initial use of angioplasty appears to decrease the need for subsequent retreatment.

Effect of Body Mass Index on Venous Sinus Pressures in Idiopathic Intracranial Hypertension Patients Before and After Endovascular Stenting.

BACKGROUND: Elevated body mass index (BMI) has been correlated with worse outcomes after treatment for idiopathic intracranial hypertension (IIH). Venous sinus stenting (VSS) has emerged as a safe and effective treatment for a subset of patients with IIH and evidence of venous sinus stenosis. However, the association between BMI and the efficacy of VSS remains poorly characterized. OBJECTIVE: To determine, in a retrospective cohort study, the effect of BMI on preoperative mean intracranial venous pressure (MVP) and post-VSS outcomes. METHODS: We performed a retrospective evaluation of a prospectively collected database of patients with IIH and intracranial venous sinus stenosis who underwent VSS. Patient demographics and treatment factors, including pre- and postprocedural trans-stenosis pressure gradients, were analyzed to identify the relationship between BMI and outcomes after VSS. RESULTS: Increasing BMI was significantly correlated with higher maximum MVP (P = .013) and higher trans-stenosis pressure gradient (P = .043) prior to treatment. The degrees of improvement in maximum MVP and pressure gradient after VSS were greatest for obese and morbidly obese patients (BMI > 30 kg/m2). Maximum poststent MVP, clinical outcomes, and stent-adjacent stenosis requiring retreatment after VSS were not significantly associated with BMI. CONCLUSION: We provide direct evidence for a positive correlation between BMI and intracranial venous pressure in patients with IIH. VSS affords a significantly greater amelioration of intracranial venous hypertension and stenosis for IIH patients with higher BMIs. As such, obesity should not be a deterrent for the use of VSS in the management of IIH.

Radiation-Induced Changes After Stereotactic Radiosurgery for Brain Arteriovenous Malformations: A Systematic Review and Meta-Analysis.

BACKGROUND: Radiation-induced changes (RICs) are the most common complication of stereotactic radiosurgery (SRS) for brain arteriovenous malformations (AVMs), and they appear as perinidal T2-weighted hyperintensities on magnetic resonance imaging, with or without associated neurological symptoms. OBJECTIVE: To determine the rates of RIC after AVM SRS and identify risk factors. METHODS: A literature review was performed using PubMed and MEDLINE to identify studies reporting RIC in AVM patients treated with SRS. RICs were classified as radiologic (any neuroimaging evidence), symptomatic (any associated neurological deterioration, regardless of duration), and permanent (neurological decline without recovery). Baseline, treatment, and outcomes data were extracted for statistical analysis. RESULTS: Based on pooled data from 51 studies, the overall rates of radiologic, symptomatic, and permanent RIC after AVM SRS were 35.5% (1143/3222 patients, 32 studies), 9.2% (499/5447 patients, 46 studies), and 3.8% (202/5272 patients, 39 studies), respectively. Radiologic RIC was significantly associated with lack of prior AVM rupture (odds ratio [OR] = 0.57; 95% confidence interval [CI]: 0.47-0.69; P < .001) and treatment with repeat SRS (OR = 6.19; 95% CI: 2.42-15.85; P < .001). Symptomatic RIC was significantly associated with deep AVM location (OR = 0.38; 95% CI: 0.21-0.67; P < .001). CONCLUSION: Approximately 1 in 3 patients with AVMs treated with SRS develop radiologically evident RIC, and of those with radiologic RIC, 1 in 4 develop neurological symptoms. Lack of prior AVM hemorrhage and repeat SRS are risk factors for radiologic RIC, and deep nidus location is a risk factor for symptomatic RIC.