Kenneth C. Liu

Endovascular vs medical management of acute ischemic stroke

Objective: To compare the outcomes between endovascular and medical management of acute ischemic stroke in recent randomized controlled trials (RCT). Methods: A systematic literature review was performed, and multicenter, prospective RCTs published from January 1, 2013, to May 1, 2015, directly comparing endovascular therapy to medical management for patients with acute ischemic stroke were included. Meta-analyses of modified Rankin Scale (mRS) and mortality at 90 days and symptomatic intracranial hemorrhage (sICH) for endovascular therapy and medical management were performed. Results: Eight multicenter, prospective RCTs (Interventional Management of Stroke [IMS] III, Local Versus Systemic Thrombolysis for Acute Ischemic Stroke [SYNTHESIS] Expansion, Mechanical Retrieval and Recanalization of Stroke Clots Using Embolectomy [MR RESCUE], Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands [MR CLEAN], Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness [ESCAPE], Extending the Time for Thrombolysis in Emergency Neurological Deficits–Intra-Arterial [EXTEND-IA], Solitaire With the Intention For Thrombectomy as Primary Endovascular Treatment [SWIFT PRIME], and Endovascular Revascularization With Solitaire Device Versus Best Medical Therapy in Anterior Circulation Stroke Within 8 Hours [REVASCAT]) comprising 2,423 patients were included. Meta-analysis of pooled data demonstrated functional independence (mRS 0–2) at 90 days in favor of endovascular therapy (odds ratio [OR] = 1.71; p = 0.005). Subgroup analysis of the 6 trials with large vessel occlusion (LVO) criteria also demonstrated functional independence at 90 days in favor of endovascular therapy (OR = 2.23; p < 0.00001). Subgroup analysis of the 5 trials that primarily utilized stent retriever devices (≥70%) in the intervention arm demonstrated functional independence at 90 days in favor of endovascular therapy (OR = 2.39; p < 0.00001). No difference was found for mortality at 90 days and sICH between endovascular therapy and medical management in all analyses and subgroup analyses. Conclusions: This meta-analysis provides strong evidence that endovascular intervention combined with medical management, including IV tissue plasminogen activator for eligible patients, improves the outcomes of appropriately selected patients with acute ischemic stroke in the setting of LVO.

Dural venous sinus angioplasty and stenting for the treatment of idiopathic intracranial hypertension

Background Lumboperitoneal shunt (LPS), ventriculoperitoneal shunt (VPS) and optic nerve sheath fenestration (ONSF) are accepted surgical therapies for medically refractory idiopathic intracranial hypertension (IIH). In the subset of patients with IIH and venous sinus stenosis, dural venous sinus stenting has emerged as an alternative surgical approach. Methods All cases of dural stents for IIH at our institution were retrospectively reviewed. Eligibility criteria included medically refractory IIH with documented papilledema and dural venous sinus stenosis of the dominant venous outflow system (gradient ≥10 mm Hg). Results Fifteen cases (all women) of mean age 34 years were identified. All had failed medical therapy and six had failed surgical intervention. Technical success was achieved in all patients without major periprocedural complications. The mean preprocedural gradient across the venous stenosis was reduced from 24 mm Hg before the procedure to 4 mm Hg after the procedure. Headache resolved or improved in 10 patients. Papilledema resolved in all patients and visual acuity stabilized or improved in 14 patients. There were no instances of restenosis among the 14 patients with follow-up imaging. Conclusion In this small case series, dural sinus stenting for IIH was performed safely with a high degree of technical success and with excellent clinical outcomes. These results suggest that angioplasty and stenting for the treatment of medically refractory IIH in patients with dural sinus stenosis warrants further investigation as an alternative to LPS, VPS and ONSF.

Management strategies for intraprocedural coil migration during endovascular treatment of intracranial aneurysms

Migration of a coil during endovascular treatment of intracranial aneurysm occurs in 2–6% of cases. The consequences of coil migration vary significantly from minor flow alterations of the parent artery which are asymptomatic to thromboembolic occlusion of major intracranial vessels resulting in large territory infarcts. We performed a comprehensive literature review and identified 37 reported cases of migrated coil retrieval consisting of 10 case reports and six case series. Most of the aneurysms presented with rupture (65%) and were located in the anterior circulation (70%). The endovascular treatment approaches were coil embolization alone (57%), stent-assisted coiling (26%) and balloon remodeling (17%). Endovascular retrieval was performed with microwires, the Alligator Retrieval device, Merci devices, snares and stentrievers. There was a single report of microsurgical extraction following failed endovascular removal and three cases of coil fracture in which the coil fragments were secured to the vessel walls with stents.

Meta-analysis of randomized intra-arterial thrombolytic trials for the treatment of acute stroke due to middle cerebral artery occlusion

Background Randomized clinical trials supporting the use of intra-arterial administration of thrombolytics (IAT) for the treatment of stroke due to middle cerebral artery (MCA) occlusion have been positive on some, but not all, endpoints. A meta-analysis was performed to estimate with more precision the effect of IAT on several key clinical endpoints. Methods All randomized trials of IAT in the treatment of MCA stroke were identified by PUBMED search and by hand search of potentially relevant references. Trial methodologies were assessed for compatibility in study protocols and statistical analysis. A meta-analysis was performed evaluating the effect of IAT on functional outcome at 90 days and symptomatic intracranial hemorrhage (SICH) within 24 h. Results Three trials met the criteria for the meta-analysis. IAT treated patients were significantly more likely to have a modified Rankin scale (mRS) ≤1 (31% vs 20%, OR 2.0, 95% CI 1.2 to 3.4, p=0.01); mRS ≤2 (43% vs 31%, OR 1.9, 95% CI 1.2 to 3.0, p=0.01); and NIH Stroke Scale score 0 or 1 (23% vs 12%, OR 2.4, 95% CI 1.3 to 4.4, p=0.007) at the 90 day follow-up. There was no effect on mortality at 90 days (20% vs 19%, OR 0.84, 95% CI 0.5 to 1.5). The risk of SICH was significantly increased in the active treatment arms (11% vs 2%, OR 4.6, 95% CI 1.3 to 16, p=0.02). Conclusions Our meta-analysis demonstrates that all standard functional endpoints for stroke trials were substantially improved in the active treatment arms. Despite an increased risk of SICH, there was no effect on mortality. These results support endovascular treatment of acute ischemic stroke due to MCA occlusion with intra-arterial thrombolytics.

Preoperative Embolization of Intracranial Meningiomas: Efficacy, Technical Considerations, and Complications

BACKGROUND AND PURPOSE: Preoperative embolization for intracranial meningiomas offers potential advantages for safer and more effective surgery. However, this treatment strategy has not been examined in a large comparative series. The purpose of this study was to review our experience using preoperative embolization to understand the efficacy, technical considerations and complications of this technique. MATERIALS AND METHODS: We performed a retrospective review of patients undergoing intracranial meningioma resection at our institution (March 2001 to December 2012). Comparisons were made between embolized and nonembolized patients, including patient and tumor characteristics, embolization method, operative blood loss, complications, and extent of resection. Logistic regression analyses were used to identify factors predictive of operative blood loss and extent of resection. RESULTS: Preoperatively, 224 patients were referred for embolization, of which 177 received embolization. No complications were seen in 97.1%. There were no significant differences in operative duration, extent of resection, or complications. Estimated blood loss was higher in the embolized group (410 versus 315 mL, P = .0074), but history of embolization was not a predictor of blood loss in multivariate analysis. Independent predictors of blood loss included decreasing degree of tumor embolization (P = .037), skull base location (P = .005), and male sex (P = .034). Embolization was not an independent predictor of gross total resection. CONCLUSIONS: Preoperative embolization is a safe option for selected meningiomas. In our series, embolization did not alter the operative duration, complications, or degree of resection, but the degree of embolization was an independent predictor of decreased operative blood loss.

The safety and effectiveness of a dural sealant system for use with nonautologous duraplasty materials

OBJECT The DuraSeal dural sealant system, a polyethylene glycol hydrogel, has been shown to be safe and effective when used with commercial and autologous duraplasty materials. The authors report on the safety and effectiveness of this sealant when used in conjunction with nonautologous duraplasty materials. METHODS In this retrospective, nonrandomized, multicenter study, the safety and efficacy of a dural sealant system was assessed in conjunction with primarily collagen-based nonautologous duraplasty materials in a sample of 66 patients undergoing elective cranial procedures at 3 institutions. This cohort was compared with 50 well-matched patients from the DuraSeal Pivotal Trial who were treated with this sealant system and autologous duraplasty material. RESULTS The key end points of the study were the incidences of CSF leaks, surgical site infections, and meningitis 90 days after surgery. The incidence of postoperative CSF leakage was 7.6% in the study group (retrospective population) and 6.0% in the Pivotal Trial population. The incidence of meningitis was 0% and 4.0% in the retrospective and Pivotal Trial groups, respectively. There were no serious device-related adverse events or unanticipated adverse device effects noted for either population. CONCLUSIONS This study demonstrates that the DuraSeal sealant system is safe and effective when used for watertight dural closure in conjunction with nonautologous duraplasty materials.

Predictive Capability of the Spetzler-Martin versus Supplementary Grading Scale for Microsurgical Outcomes of Cerebellar Arteriovenous Malformations

The recently described supplementary grading scale may be superior to the widely used Spetzler-Martin grading scale in the prediction of microsurgical outcomes for cerebellar arteriovenous malformations (AVM). We report two cases of ruptured cerebellar AVMs with the same Spetzler-Martin grade but different supplementary grades treated with microsurgical resection. Both patients had symptomatic brainstem compression from cerebellar hematomas and subsequently underwent uncomplicated surgeries; however, their outcomes were significantly different. It has previously been proposed that AVMs distort cerebellar anatomy in a different manner than supratentorial cerebral anatomy thereby potentially resulting in misrepresentation when utilizing the Spetzler-Martin grading scale. However, the components of the supplementary grading scale are independent of cerebellar anatomy, which may explain why it has been shown to be better than the Spetzler-Martin grading scale for prediction of surgical outcomes. In addition, due to the smaller volume of the posterior fossa compared to the supratentorial compartment, rupture of cerebellar AVMs may result in rapid and catastrophic neurological compromise. Therefore, the role of microsurgery may be more critical for AVMs of the cerebellar than for those located elsewhere. Simple and effective grading systems are invaluable tools for clinical and surgical decision-making, although the decisions rendered should always be made in conjunction with the patients presentation and the physicians experience.

Endovascular treatment of unruptured wide-necked intracranial aneurysms: comparison of dual microcatheter technique and stent-assisted coil embolization

Background Endovascular treatment of wide-necked aneurysms is challenging. Stent-assisted coiling (SAC) is associated with increased complications and requires dual antiplatelet therapy. Objective To compare treatment of unruptured, wide-necked aneurysms with a dual-microcatheter technique (DMT) versus SAC. Methods Between 2006 and 2011, 100 patients with unruptured wide-necked intracranial aneurysms were treated with DMT and 160 with SAC. Over time there was a significant decrease in the use of SAC and a corresponding increase in DMT. The investigators matched 60 patients treated with DMT blinded to outcome in a 1:2 fashion based on maximal aneurysm dome diameter with 120 patients treated with SAC. Outcomes were determined with conditional (matched) multivariate analysis. Results There were no significant differences in patient or aneurysm characteristics between cohorts, including aneurysm diameter, neck width, or volume. Overall packing density and coil volume achieved was not significantly different between cohorts. There were higher rates of overall complications in those receiving SAC (19.2%) compared with DMT (5.0%; p=0.012), but no significant difference in major complications (8.3% vs 1.7%, respectively; p=0.103). At a mean follow-up of 27.0±18.9 months, rates of retreatment did not differ between DMT (15.1%) and SAC (17.7%). Delayed in-stent stenosis occurred in five patients and in-stent thrombosis in four patients treated with SAC. There was no difference in favorable functional outcome (modified Rankin score 0–2) between those treated with DMT (90.6%) compared with SAC (91.2%). Conclusions DMT and SAC are effective endovascular approaches for unruptured, wide-necked aneurysms; however, DMT may result in less morbidity. Further long-term studies are necessary to determine the optimal indications for these treatment options.

Role of Stenting for Intracranial Atherosclerosis in the Post-SAMMPRIS Era

Introduction. The initial promise of endovascular stenting for the treatment of intracranial atherosclerotic disease (ICAD) has been tempered by the results of the SAMMPRIS trial which demonstrated better outcomes with medical management compared to stenting for symptomatic ICAD. We review post-SAMMPRIS ICAD stenting outcomes. Methods. A comprehensive literature search was performed using PubMed to identify all ICAD stenting series published after the SAMMPRIS in September 2011. The type and design of the stent, number of patients and lesions, inclusion criteria, and clinical and angiographic outcomes were noted. Results. From October 2011 to August 2013, 19 ICAD stenting series were identified describing the interventional outcomes for 2,196 patients with 2,314 lesions. Of the 38 different stents used, 87% were balloon-expandable stents (BESs) and 13% were self-expanding stents. The median minimum stenosis was 50%. The median rates of technical success rate, postprocedural ischemic events, and symptomatic in-stent restenosis (ISR) were 98% (range 87–100%), 9.4% (range 0–25%), and 2.7% (range 0–11.1%), respectively. The median follow-up durations were one to 67 months. Conclusions. The management of severe ICAD remains controversial. Future trials are needed to define the optimal patient, lesion, and stent characteristics which will portend the best outcomes with intervention.

Intraprocedural retrieval of migrated coils during endovascular aneurysm treatment with the Trevo Stentriever device

Coil migration during endovascular treatment of intracranial aneurysms occurs in 2-6% of cases. As endovascular coiling of aneurysms has become increasingly popular and as endovascular technology continues to rapidly evolve, the prevalence of intraprocedural coil migration will invariably rise. Since coil masses are highly thrombogenic, migration out of the aneurysm sac into the parent artery may result in large territory infarcts which subsequently manifest as significant neurological morbidity. Therefore safe and timely retrieval of migrated coils is essential to avoiding poor angiographic and clinical outcomes. A 66-year-old woman with an unruptured 5 × 3mm, wide-necked posterior communicating artery aneurysm was referred for endovascular treatment. During coiling with the dual catheter technique, both initially deployed coils dislodged from the aneurysm sac and migrated distally into the middle cerebral artery. After failed retrieval with an Alligator device (Chestnut Medical Technologies, Menlo Park, CA, USA), we used two Trevo devices (Concentric Medical, Mountain View, CA, USA) in succession to successfully retrieve the migrated coils. The aneurysm was then occluded with stent-assisted coil embolization. There were no post-procedural angiographic or clinical complications. The patient was subsequently discharged home without neurological deficit. This case illustrates the first use of the Trevo device for retrieval of migrated coils during endovascular treatment of an intracranial aneurysm to our knowledge. Due to the lack of guidelines defining the standard management of intraprocedural coil migration, current strategies are based on retrospective review of published reports and expert opinion. We present a unique and effective method for endovascular retrieval of displaced coils using a Trevo Stentriever device.