Hussain Shallwani

Use of Platelet Function Testing Before Pipeline Embolization Device Placement: A Multicenter Cohort Study

Background and Purpose— Thromboembolic complications constitute a significant source of morbidity after neurointerventional procedures. Flow diversion using the pipeline embolization device for the treatment of intracranial aneurysms necessitates the use of dual antiplatelet therapy to reduce this risk. The use of platelet function testing before pipeline embolization device placement remains controversial. Methods— A retrospective review of prospectively maintained databases at 3 academic institutions was performed from the years 2009 to 2016 to identify patients with intracranial aneurysms treated with pipeline embolization device placement. Clinical and radiographic data were analyzed with emphasis on thromboembolic complications and clopidogrel responsiveness. Results— A total of 402 patients underwent 414 pipeline embolization device procedures for the treatment of 465 intracranial aneurysms. Thromboembolic complications were encountered in 9.2% of procedures and were symptomatic in 5.6%. Clopidogrel nonresponders experienced a significantly higher rate of thromboembolic complications compared with clopidogrel responders (17.4% versus 5.6%). This risk was significantly lower in nonresponders who were switched to ticagrelor when compared with patients who remained on clopidogrel (2.7% versus 24.4%). In patients who remained on clopidogrel, the rate of thromboembolic complications was significantly lower in those who received a clopidogrel boost within 24 hours pre-procedure when compared with those who did not (9.8% versus 51.9%). There was no significant difference in the rate of hemorrhagic complications between groups. Conclusions— Clopidogrel nonresponders experienced a significantly higher rate of thromboembolic complications when compared with clopidogrel responders. However, this risk seems to be mitigated in nonresponders who were switched to ticagrelor or received a clopidogrel boost within 24 hours pre-procedure.

Management of acute ischemic stroke due to tandem occlusion: should endovascular recanalization of the extracranial or intracranial occlusive lesion be done first?

OBJECTIVE Acute tandem occlusions of the cervical internal carotid artery and an intracranial large vessel present treatment challenges. Controversy exists regarding which lesion should be addressed first. The authors sought to evaluate the endovascular approach for revascularization of these lesions at Gates Vascular Institute. METHODS The authors performed a retrospective review of a prospectively maintained, single-institution database. They analyzed demographic, procedural, radiological, and clinical outcome data for patients who underwent endovascular treatment for tandem occlusions. A modified Rankin Scale (mRS) score ≤ 2 was defined as a favorable clinical outcome. RESULTS Forty-five patients were identified for inclusion in the study. The average age of these patients was 64 years; the mean National Institutes of Health Stroke Scale score at presentation was 14.4. Fifteen patients received intravenous thrombolysis before undergoing endovascular treatment. Thirty-seven (82%) of the 45 proximal cervical internal carotid artery occlusions were atherothrombotic in nature. Thirty-eight patients underwent a proximal-to-distal approach with carotid artery stenting first, followed by intracranial thrombectomy, whereas 7 patients underwent a distal-to-proximal approach (that is, intracranial thrombectomy was performed first). Thirty-seven (82%) procedures were completed with local anesthesia. For intracranial thrombectomy procedures, aspiration alone was used in 15 cases, stent retrieval alone was used in 5, and a combination of aspiration and stent-retriever thrombectomy was used in the remaining 25. The average time to revascularization was 81 minutes. Successful recanalization (thrombolysis in cerebral infarction Grade 2b/3) was achieved in 39 (87%) patients. Mean National Institutes of Health Stroke Scale scores were 9.3 immediately postprocedure (p < 0.05) (n = 31), 5.1 at discharge (p < 0.05) (n = 31), and 3.6 at 3 months (p < 0.05) (n = 30). There were 5 in-hospital deaths (11%); and 2 patients (4.4%) had symptomatic intracranial hemorrhage within 24 hours postprocedure. Favorable outcomes (mRS score ≤ 2) were achieved at 3 months in 22 (73.3%) of 30 patients available for follow-up, with an mRS score of 3 for 7 of 30 (23%) patients. CONCLUSIONS Tandem occlusions present treatment challenges, but high recanalization rates were possible in the present series using acute carotid artery stenting and mechanical thrombectomy concurrently. Proximal-to-distal and aspiration approaches were most commonly used because they were safe, efficacious, and feasible. Further study in the setting of a randomized controlled trial is needed to determine the best sequence for the treatment approach and the best technology for tandem occlusion.

Vessel perforation during stent retriever thrombectomy for acute ischemic stroke: technical details and clinical outcomes

Background Vessel perforation during stent retriever thrombectomy is a rare complication; typically only single instances have been reported. Objective To report on a series of patients whose stent retriever thrombectomy was complicated by intraprocedural vessel perforation and discuss its potential mechanisms, rescue treatment strategies, and clinical significance. Methods Cases with intraprocedural vessel perforation, where a stent retriever was used either as a primary treatment approach or as a part of a direct aspiration first pass technique (ADAPT), were included in the final analysis. Clinical data, procedural details, radiographic and clinical outcomes were collected from nine participating centers. Results Intraprocedural vessel perforation during stent retriever thrombectomy occurred in 16 (1.0%) of 1599 cases. 63% of intraprocedural perforations occurred at distal locations. Endovascular rescue techniques (most commonly, intracranial balloon occlusion for tamponade) were attempted in 50% of cases. Procedure was aborted without any rescue attempts in 44% of cases. Mortality during hospitalization and at 3 months was 56% and 63%, respectively. 25% of patients achieved good functional outcome at 3 months after the procedure. Conclusions Intraprocedural perforations during stent retriever thrombectomy were rare, but when they occurred were associated with high mortality. Perforations most commonly occurred at distal occlusion sites and were often characterized by difficulty traversing the occlusion with a microcatheter or microwire, or while withdrawing the stent retriever. Nevertheless, 25% of patients had a favorable functional outcome, suggesting that in some patients with this complication good neurological recovery is achievable.

Safety and Efficacy of Noncompliant Balloon Angioplasty for the Treatment of Subarachnoid Hemorrhage–Induced Vasospasm: A Multicenter Study

OBJECTIVE Cerebral vasospasm following subarachnoid hemorrhage is the most important cause of neurologic decline after successful treatment of the ruptured aneurysm. We report safety and efficacy of noncompliant balloon angioplasty for treatment of cerebral vasospasm. METHODS Three major U.S. academic institutions provided data on cerebral vasospasm treated with noncompliant balloon angioplasty between October 2004 and February 2016. Baseline characteristics, procedure details, and radiographic and clinical outcome data were collected and analyzed. RESULTS There were 52 patients (median age 50 years; range, 27-73 years) who underwent 165 noncompliant balloon angioplasty procedures. Balloon angioplasty was performed most frequently in the middle cerebral artery (MCA) (49.1%) followed by the internal carotid artery (27.2%). Improvement in vasospasm severity occurred in 160 arteries (97.0%) without procedure-related complications. No independent predictor of angioplasty success was identified on multivariate analysis. Delayed cerebral ischemia occurred in 24 patients (46.2%) encompassing 36 vascular territories. The rate of delayed cerebral ischemia in territories supplied by vessels that underwent angioplasty at least once was 29.4%, 24.2%, 19.3%, and 0% for the anterior cerebral artery (ACA) territory, internal carotid artery territory (ACA, ACA/MCA watershed, or MCA), MCA territory, and posterior circulation. CONCLUSIONS Our data suggest that noncompliant balloon angioplasty for treatment of subarachnoid hemorrhage-induced cerebral vasospasm is safe and effective. No predictors of angioplasty success were identified. The rate of delayed cerebral ischemia in territories supplied by vessels that underwent angioplasty was highest in the ACA territory and lowest in the posterior circulation.

Correlation between cerebral blood volume values and outcomes in endovascular therapy for acute ischemic stroke

Background Neurointerventionalists do not agree about the optimal imaging protocol when evaluating patients with acute stroke for potential endovascular revascularization. Preintervention cerebrovascular blood volume (CBV) has been shown to predict outcomes in patients undergoing intra-arterial stroke therapies. Objective To determine whether CBV can predict hemorrhagic transformation and clinical outcomes in patients selected for endovascular therapy for acute ischemic middle cerebral artery (MCA) stroke using a CT perfusion (CTP)-based imaging protocol. Methods We retrospectively reviewed cases of acute ischemic stroke due to MCA M1 segment occlusion and correlated favorable clinical outcomes (modified Rankin scale (mRS) ≤2) and radiographic outcomes with preintervention CBV values. All patients underwent whole-brain (320-detector-row) CTP imaging, and absolute CBV values of the affected and contralateral MCA territories were obtained separately for the cortical and basal ganglia regions. Results Relative CBV (rCBV) of the MCA cortical regions was significantly lower in patients with poor clinical outcomes than in those with favorable clinical outcomes (0.87±0.21 vs 1.02±0.09, p=0.0003), and a negative correlation was found between rCBV values and mRS score severity. rCBV of the basal ganglia region was significantly lower in patients with hemorrhagic infarction (p=0.004) and parenchymal hematoma (p=0.04) than in those without hemorrhagic transformation. Conclusions We found that cortical CBV loss is predictive of poor clinical outcomes, whereas basal ganglia CBV loss is predictive of hemorrhagic transformation but without translation into poor clinical outcomes. Our study findings support published results of baseline preintervention CBV as a predictor of outcomes in patients undergoing intra-arterial stroke therapies.

Mandatory Change From Surgical Skull Caps to Bouffant Caps Among Operating Room Personnel Does Not Reduce Surgical Site Infections in Class I Surgical Cases: A Single-Center Experience With More Than 15 000 Patients

BACKGROUND Surgical site infections (SSIs) are noteworthy and costly complications. New recommendations from a national organization have urged the elimination of traditional surgeons caps (surgical skull caps) and mandated the use of bouffant caps to prevent SSIs. OBJECTIVE To report SSI rates for >15 000 class I (clean) surgical procedures 13 mo before and 13 mo after surgical skull caps were banned at a single site with 25 operating rooms. METHODS SSI data were acquired from hospital infection control monthly summary reports from January 2014 to March 2016. Based on a change in hospital policy mandating obligatory use of bouffant caps since February 2015, data were categorized into nonbouffant and bouffant groups. Monthly and cumulative infection rates for 13 mo before (7513 patients) and 13 mo after (8446 patients) the policy implementation were collected and analyzed for the groups, respectively. RESULTS An overall increase of 0.07% (0.77%-0.84%) in the cumulative rate of SSI in all class I operating room cases and of 0.03% (0.79%-0.82%) in the cumulative rate of SSI in all spinal procedures was noted. However, neither increase reached statistical significance (P > .05). The cumulative rate of SSI in neurosurgery craniotomy/craniectomy cases decreased from 0.95% to 0.75%; this was also not statistically significant (P = 1.00). CONCLUSION National efforts at improving healthcare performance are laudable but need to be evidence based. Guidelines, especially when applied in a mandatory fashion, should be assessed for effectiveness. In this large, single-center series of patients undergoing class I surgical procedures, elimination of the traditional surgeons cap did not reduce infection rates.

Endovascular treatment of middle cerebral artery M2 occlusion strokes: Clinical and procedural predictors of outcomes

BACKGROUND: Patients with strokes from M2 segment middle cerebral artery (MCA) occlusion have been underrepresented in recent randomized trials of endovascular therapy. OBJECTIVE: To better understand the clinical, imaging, and procedural predictors of successful recanalization and clinical outcomes in this population of patients. METHODS: We performed a multicenter retrospective analysis of consecutive patients with acute MCA M2 segment occlusion who underwent thrombectomy with stent retrievers or primary aspiration thrombectomy (including A Direct Aspiration First Pass Technique approach). We correlated clinical and radiographic outcomes with demographic, clinical, and technical characteristics. RESULTS: One hundred and seventeen patients were included in analysis (median admission National Institutes of Health stroke scale [NIHSS] score 15, mean age 67.0 ± 14.5, 42% females). Good clinical outcome at 3 months (modified Rankin scale [mRS] ≤ 2) was achieved in 56% of patients. Treatment beyond 6 h of symptoms onset (P = .69, OR 0.80, 95% CI 0.38‐1.73) and age over 80 (P = .47, OR 0.65, 95% CI 0.25‐1.70) were not predictive of poor outcome. NIHSS > 15 was a strong predictor of clinical outcome, based on mRS distribution at 3 months (P = .0085, OR 0.35, 95% CI 0.16‐0.74). Direct aspiration and primary stent retriever thrombectomy approaches showed similar radiographic and clinical success rates. CONCLUSION: Advanced age and time to treatment beyond 6 h from symptom onset were not predictive of clinical outcome with thrombectomy. NIHSS score above 15 was a strong predictor of outcome. Direct aspiration and primary stent retriever thrombectomy showed similar efficacy.

Ischemic Stroke After Treatment of Intraprocedural Thrombosis During Stent-Assisted Coiling and Flow Diversion

Background and Purpose— Intraprocedural thrombosis poses a formidable challenge during neuroendovascular procedures because the risks of aggressive thromboembolic treatment must be balanced against the risk of postprocedural hemorrhage. The aim of this study was to identify predictors of ischemic stroke after intraprocedural thrombosis after stent-assisted coiling and pipeline embolization device placement. Methods— A retrospective analysis of intracranial aneurysms treated with stent-assisted coiling or pipeline embolization device placement between 2007 and 2016 at 4 major academic institutions was performed to identify procedures that were complicated by intraprocedural thrombosis. Results— Intraprocedural thrombosis occurred in 34 (4.6%) procedures. Postprocedural ischemic stroke and hemorrhage occurred in 20.6% (7/34) and 11.8% (4/34) of procedures complicated by intraprocedural thrombosis, respectively. Current smoking was an independent predictor of ischemic stroke. There was no statistically significant difference in the rate of ischemic stroke or postprocedural hemorrhage with the use of abciximab compared with the use of eptifibatide in treatment of intraprocedural thrombosis. Conclusions— Current protocols for treatment of intraprocedural thrombosis associated with placement of intra-arterial devices were effective in preventing ischemic stroke in ≈80% of cases. Current smoking was the only independent predictor of ischemic stroke.

Predictors of Incomplete Occlusion following Pipeline Embolization of Intracranial Aneurysms: Is It Less Effective in Older Patients?

This was a retrospective analysis of 465 consecutive aneurysms treated with the Pipeline Embolization Device between 2009 and 2016, at 3 academic institutions in the United States. Cases with angiographic follow-up were selected to evaluate factors predictive of incomplete aneurysm occlusion at last follow-up. Older age (more than 70 years), nonsmoking status, aneurysm location within the posterior communicating artery or posterior circulation, greater aneurysm maximal diameter (>21 mm), and shorter follow-up time (<12 months) were significantly associated with incomplete aneurysm occlusion at last angiographic follow-up. BACKGROUND AND PURPOSE: Flow diversion with the Pipeline Embolization Device (PED) for the treatment of intracranial aneurysms is associated with a high rate of aneurysm occlusion. However, clinical and radiographic predictors of incomplete aneurysm occlusion are poorly defined. In this study, predictors of incomplete occlusion at last angiographic follow-up after PED treatment were assessed. MATERIALS AND METHODS: A retrospective analysis of consecutive aneurysms treated with the PED between 2009 and 2016, at 3 academic institutions in the United States, was performed. Cases with angiographic follow-up were selected to evaluate factors predictive of incomplete aneurysm occlusion at last follow-up. RESULTS: We identified 465 aneurysms treated with the PED; 380 (81.7%) aneurysms (329 procedures; median age, 58 years; female/male ratio, 4.8:1) had angiographic follow-up, and were included. Complete occlusion (100%) was achieved in 78.2% of aneurysms. Near-complete (90%–99%) and partial (<90%) occlusion were collectively achieved in 21.8% of aneurysms and defined as incomplete occlusion. Of aneurysms followed for at least 12 months (211 of 380), complete occlusion was achieved in 83.9%. Older age (older than 70 years), nonsmoking status, aneurysm location within the posterior communicating artery or posterior circulation, greater aneurysm maximal diameter (≥21 mm), and shorter follow-up time (<12 months) were significantly associated with incomplete aneurysm occlusion at last angiographic follow-up on univariable analysis. However, on multivariable logistic regression, only age, smoking status, and duration of follow-up were independently associated with occlusion status. CONCLUSIONS: Complete occlusion following PED treatment of intracranial aneurysms can be influenced by several factors related to the patient, aneurysm, and treatment. Of these factors, older age (older than 70 years) and nonsmoking status were independent predictors of incomplete occlusion. While the physiologic explanation for these findings remains unknown, identification of factors predictive of incomplete aneurysm occlusion following PED placement can assist in patient selection and counseling and might provide insight into the biologic factors affecting endothelialization.

Safety and Efficacy of the Sofia (6F) PLUS Distal Access Reperfusion Catheter in the Endovascular Treatment of Acute Ischemic Stroke

BACKGROUND Neuroendovascular intervention has become a key treatment option for acute ischemic stroke. The Sofia (6F) PLUS catheter was designed for neurovascular access for diagnostic or therapeutic interventions. OBJECTIVE To report the first series describing use of the Sofia PLUS intermediate/distal access reperfusion catheter in the treatment of acute ischemic stroke. METHODS In this retrospective study, 41 stroke cases were identified in which the catheter was utilized for thrombolysis/thrombectomy. Mean preprocedure National Institutes of Health Stroke Scale score was 16.5 ± 5.2 (range 4-29). Occluded vessels included the M1 segment, M2 segment, internal carotid artery terminus, cervical internal carotid artery, and basilar artery. RESULTS Successful positioning of the Sofia PLUS catheter near the occlusion site was achieved in 38 (92.7%) of 41 cases in which thrombectomy or thrombolysis was attempted using intraarterial tissue plasminogen activator, a direct aspiration first-pass technique, and/or stent retrieval. A postprocedure thrombolysis in cerebral infarction (TICI) score of 2b/3 was achieved in 37 of 41 cases. Of 15 cases where the Sofia PLUS was used for a direct aspiration first-pass technique, TICI 2b/3 was achieved in 11 (73.3%). In one case where intra-arterial tissue plasminogen activator was used as the only treatment modality, TICI 2a was achieved. No device-related or catheter-related complications were observed. The mean 7-d-postprocedure National Institutes of Health Stroke Scale score among the 39 survivors was 8.5 ± 7.3 (range 0-23). CONCLUSION Initial results with use of the Sofia (6F) PLUS for endovascular treatment of acute ischemic stroke have been encouraging. Experience with a larger series is warranted to further evaluate the safety and efficacy of this device and compare it with other reperfusion catheters.