Faculty Bibliography

The concept of Nash equilibrium, developed by John Forbes Nash Jr, states that an equilibrium in noncooperative games is reached when each player takes the best action for himself or herself, taking into account the actions of the other players. We apply this concept to the provision of endovascular thrombectomy in the treatment of acute ischemic stroke and suggest that collaboration among hospitals in a health care jurisdiction could result in practices such as shared call pools for neurointervention teams, leading to better patient care through streamlined systems.

Introduction: The efficacy of MDCT-based-angiography in management of acute stroke and/or emergent-large-vessel-occlusion is well established. However, concern for contrast-induced nephropathy(CIN) especially in patients with major risk factors like Diabetes & Chronic kidney disease often delays rapid evaluation of ELVO patients. Many published studies report the overall incidence of CIN after administration of IV or IA iodinated contrast and highlight the direct correlation of dose on higher incidence of CIN. None, however, have examined impact of sequential IV-IA bolus for neuroangiographic evaluation on renal function in patients with DM and/or CKD. Methods: A retrospective study of our 2015-2017 stroke database of 168 patients was conducted to identify all patients with preexisting DM and/or CKD who developed CIN during their hospital course. We also reviewed the prevalence of dehydration (BUN/Cr <20), CHF and anemia (Hb <8 g/dL) for these patients on admission. Results: For all 168 patients; average IA, IV and cumulative IV-IA contrast (Omnipaque 350) doses within 24 hours were 89.9, 91.7 and 181.6 cc respectively. 68 patients had DM and/or CKD of which 3 developed CIN. Under the definition of >=25% increase in baseline Cr within 72-120 hours of receiving contrast, all 3 had CIN. However, under the definition of >=0.5 mg/dL increase in Cr within 72 hours, none had CIN. All 3 only had preexisting DM as risk factor and had age appropriate baseline Cr on admission. The baseline Cr for each of the 3 patients were 0.82, 1.17 & 0.47 mg/dL respectively while the elevated Cr were 1.03, 1.17 & 0.76 mg/dL respectively. All 3 returned to within baseline by discharge with no mortality or need for hemodialysis. Conclusions: There is low risk of developing CIN in high risk patients like CKD or DM following rapid sequential dual IV/IA contrast bolus in acute stroke patients and therefore should not delay rapid neuro-angiographic evaluation

Introduction: Most stroke/neuro-interventional centers require advanced biplane imaging for evaluation of complex cerebrovascular lesions. Purchasing such equipment is cost-prohibitive for many hospital systems. Additionally, operator-preference often prevents the use of other imaging platforms as a back up for acute neuro-interventional cases. However, most hospitals are often equipped with multiple single plane imaging platforms for IR & Cardiac purposes. Advanced single plane imaging in most catheterization labs provide reasonable penetration and field of view (FOV) for doing acute cases like mechanical thrombectomy. Methods: A retrospective review of our multi-center database of acute stroke patients treated with endovascular therapy was performed. 207 patients were categorized by type of imaging platform on which thrombectomy was performed and relevant angiographic and clinical data was gathered. Primary outcome was measured using angiographic outcome. This included comparisons between two groups of TICI scores: TICI 0-2A vs. TICI 2B-3 and TICI 2B vs. TICI 2C/3. Secondary outcome was safety which was reported as incidence of intracranial hemorrhage between the two groups Results: 146 biplane patients achieved scores of 2B or higher, meanwhile 12 biplane patients received scores of 2A or lower. 44 of 49 single plane patients achieved TICI scores of 2B-3 while 5 had scores of 0-2A, showing no significant difference (p > 0.05). In a second comparison, 97 biplane patients that had outcomes of 2C or 3, and 49 patients with outcomes of 2B; while 29 monoplane patients achieved a score of 2c or 3 and 15 with 2B (p > 0.05). For our secondary measure, ICH in the biplane group was 38/146 and in monoplane group was 9/49, the difference not being statistically significant (p > 0.05) Conclusions: There was no significant difference in safety or efficacy outcomes when comparing thrombectomies performed using biplane vs. monoplane imaging. Thrombectomies performed with either imaging system is equally safe and effective

Introduction: Chronic subdural hematoma (cSDH) can be associated with slow cognitive decline, co-ordination symptoms and rarely motor-sensory deficits. Open surgical treatment may or may not be always effective or indicated. Some far east operators have studied hypertrophy of Middle Meningeal Artery (MMA) and its embolization for treatment of such recalcitrant lesions. We present our experience of MMA embolization as an earlyadoptive technique for treatment for poor or failed surgical candidates. Methods: 10 patients diagnosed with unilateral or bilateral cSDH underwent MMA embolization. Size of SDH volume and densities were measured from time of initial discovery on imaging to pre-operative, immediate postoperative, and long-term follow-up. Time between procedure to obliteration was also measured based on follow-up imaging. Results: Out of 10 patients, 5 patients were diagnosed with recurrent cSDH, and 5 with primary cSDH. 7 patients had bilateral cSDH, and 3 unilateral cSDH. Average volume on admission and pre-operatively were 20.7 and 20.6 cc, respectively. MMA embolization was on average performed of 26 days post symptoms onset. Immediate post-op CT was performed an average of 46 hours and showed enhancement of the subdural in 40% cases. This was associated with greater visualization of their extent with average increase in SDH volume to 21.2 cc. Follow-up CT imaging for these patients was done at an average of 128 days post-procedure. Average volume was down to 13.13 cc with mean reduction of 45% from presentation. 3 patients were determined to have complete obliteration after 1 year. Conclusions: MMA Embolization has been shown to have a marked reduction in SDH volume post-operatively and can be used as a curative measure for patients who fail conservative medical management and neurosurgical intervention

Introduction: Eptifibatide (Integrilin) has been demonstrated to improve clinical outcomes in both intracoronary and carotid artery stenting, when administered perioperatively. This evidence promotes the investigation of eptifibatide's role in neuroendovascular stenting. Methods: 38 patients between 2013-2017 underwent intracranial stenting with eptifibatide administration within 24 hours of procedure. Cumulative and average eptifibatide dosages were determined for all patients. Peri and post-procedural bleeding complications were defined as intercranial hemorrhage (ICH), symptomatic intercranial hemorrhage (sICH), and peripheral bleeding (retroperitoneal, access site bleeding, GI bleeding). Final Thrombolysis in Cerebral Infarction (TICI) scores as well as modified Rankin Scales (mRS) at discharge were also collected. Comparisons of these outcomes were made between patients with high-dose Integrilin and low-dose Integrilin, which we defined as above or equal to and below 0.75 mcg/kg/ min, respectively. A similar comparison was performed for patients who received above and below calculated dosage of median cumulative dose (0.71 mg/kg) Results: Of all 38 patients, 7 (21.8%) patients were found to have intracerebral hemorrhage, with 3 of these patients showing symptoms. Additionally, 6 patients (18.7%) experienced peripheral bleeding complications. Mean eptifibatide dosage was determined to be 0.77 mcg/kg/min. Analysis of the primary endpoint of all-cause bleeding complications yielded no significance between high-dose and low-dose Integrilin (p > 0.05). However, the incidence of sICH was significantly greater in patients receiving an average dosage at 0.75 mcg/kg/min or higher (p < 0.05). Furthermore, angiographic assessment revealed that more patients who receive a cumulative dosage of 0.71 mg/kg or greater achieved a TICI score of 2c-3 in comparison to those who achieved TICI 2b (p < 0.05). Conclusions: Usage of eptifibatide for patients undergoing neurovascular stenting at higher average dosages may result in a higher incidence of symptomatic ICH, however higher cumulative dosages may improve angiographic outcomes

Introduction: Eptifibitide is a commonly used antithrombotic shown to reduce ischemic complications related to percutaneous coronary intervention. Recent findings suggest that eptifibatide administration has the potential to improve post-procedural outcomes in the context of neuroendovascular therapy for acute ischemic stroke. Methods: 49 patients between 2014 and 2017 underwent thrombectomy for acute stroke and received eptifibitide. Cumulative and average eptifibatide dosages were determined for all patients. Peri- and and post-procedural bleeding complications were categorized into: intercranial hemorrhage (ICH), symptomatic intercranial hemorrhage (sICH), and peripheral bleeding (retroperitoneal, access site bleeding, and GI bleeding). Additionally, reperfusion Thrombolysis in Cerebral Infarction (TICI) scores as well as discharge modified Rankin Scales (mRS) were also collected. Patients were divided into those who received an average infusion rate of 0.75 mcg/kg/min or higher and those who received lower, with rates of functional and clinical outcomes analyzed. An identical analysis was done for patients above and below median cumulative dosage (0.32 mg/kg). Results: Of 49 total patients, 16 (32.7%) patients were found to have intracranial hemorrhage, with 5 showing resulting clinical symptoms. 14 patients (28.6%) experienced peripheral bleeding complications. The mean eptifibatide infusion for the selected patients was 0.75 mcg/kg/min with a median cumulative dosage of 0.32 mg/kg. On analysis, patients who received a higher average infusion of eptifibitide had higher incidence of all-cause bleeding complications (p < 0.05), however individual analysis of each bleeding complication showed no significant relationship (p > 0.05). Additionally, patients who received higher infusions of eptifibitide or higher cumulative doses of eptifibitide increased rate of achieving TICI scores of 2c-3 in comparison to patients who achieved a TICI score of 2b (p < 0.05). Conclusions: Usage of eptifibatide for patients undergoing neuroendovascular therapy for acute stroke at increased dosages may increase risk of overall bleeding complications. Higher dosage or infusion rate of eptifibatide may contribute to better post-procedural cerebral reperfusion

Spontaneous intracerebral hemorrhage (ICH), defined as nontraumatic bleeding into the brain parenchyma, is the second most common subtype of stroke, with 5.3 million cases and over 3 million deaths reported worldwide in 2010. Case fatality is extremely high (reaching approximately 60 % at 1 year post event). Only 20 % of patients who survive are independent within 6 months. Factors such as chronic hypertension, cerebral amyloid angiopathy, and anticoagulation are commonly associated with ICH. Chronic arterial hypertension represents the major risk factor for bleeding. The incidence of hypertension-related ICH is decreasing in some regions due to improvements in the treatment of chronic hypertension. Anticoagulant-related ICH (vitamin K antagonists and the newer oral anticoagulant drugs) represents an increasing cause of ICH, currently accounting for more than 15 % of all cases. Although questions regarding the optimal medical and surgical management of ICH still remain, recent clinical trials examining hemostatic therapy, blood pressure control, and hematoma evacuation have advanced our understanding of ICH management. Timely and aggressive management in the acute phase may mitigate secondary brain injury. The initial management should include: initial medical stabilization; rapid, accurate neuroimaging to establish the diagnosis and elucidate an etiology; standardized neurologic assessment to determine baseline severity; prevention of hematoma expansion (blood pressure management and reversal of coagulopathy); consideration of early surgical intervention; and prevention of secondary brain injury. This review aims to provide a clinical approach for the practicing clinician.