Technical Nuances and Outcomes of Telescoping Pipeline Flow Diverters: A Multicenter Study.

BACKGROUND: "Telescoping" multiple overlapping Pipeline Embolization Devices (PEDs; Medtronic) has increased their utility by allowing for more impermeable coverage and providing the ability to off-set landing zone sites and extend treatment constructs. OBJECTIVE: To consider the technical nuances and challenges of telescoping PEDs for the treatment of intracranial aneurysms. METHODS: Databases from 3 U.S. academic neurovascular centers were retrospectively queried to identify patients with intracranial aneurysms treated with multiple PED constructs. Data on patient and aneurysm characteristics, as well as outcomes including Raymond-Roy occlusion classification, modified Rankin Scale score, and complications, were gathered. RESULTS: Forty-six patients had 48 intracranial aneurysms treated, including 16 (33%) in whom placement of telescoping PEDs was planned. Fourteen (30%) patients presented with a ruptured aneurysm. Twenty-one aneurysms (44%) were treated with proximal extension, 13 (27%) with distal extension, and 14 (29%) with PED placement inside one another. Thirty (70%) patients had complete aneurysm occlusion at follow-up. Two (4%) patients had to be retreated. Three patients with unruptured and 1 with ruptured aneurysm had a permanent intraprocedural complication. We present descriptive cases illustrating PEDs that were placed inside one another, proximally, distally, and to improve wall apposition because of vessel tortuosity. CONCLUSION: Our data indicate a higher than expected complication rate that is likely because of the technical complexity of these cases. The case illustrations presented demonstrate the indications and challenging aspects of telescoping PEDs.

Untangling the Modern Treatment Paradigm for Unruptured Brain Arteriovenous Malformations.

Brain arteriovenous malformations (AVMs) often present treatment challenges. Patients with unruptured AVMs must consider not only whether they want to be treated, but what treatment modality they would prefer. Vascular neurosurgeons, neurointerventional surgeons, and stereotactic radiosurgeons must in turn guide their patients through the most appropriate treatment course considering the risk of AVM rupture, an individual AVM's characteristics, and patient preferences. In this review we will look at how the clinical trial "A Randomized Trial of Unruptured Brain Arteriovenous Malformations (ARUBA)" has influenced the approach to unruptured brain AVMs and the treatment modalities available to clinicians to deal with these formidable lesions.

Comparative Analysis of Unruptured Cerebral Aneurysm Treatment Outcomes and Complications with the Classic versus Flex Pipeline Embolization Devices and Phenom versus Marksman Microcatheter Delivery System: The Role of Microcatheter Choice on Complication Rate.

OBJECTIVE: The second-generation pipeline embolization device (PED), flex, has improved opening and resheathing ability compared to the first-generation classic PED device. A previously reported single-institutional study suggests that the PED flex devices are associated with lower rates of complications. However, there was limited discussion regarding the complication rate with respect to microcatheter choice for PED delivery and deployment. The present study aims to evaluate outcomes of aneurysm treatment with PED flex versus classic along with the Phenom microcatheter versus Marksman microcatheter. METHODS: A retrospective, IRB-approved database of all patients who received a PED classic or PED flex device between January 2012 and July 2018 was analyzed. Microcatheter choice, patient demographics, medical comorbidities, aneurysm characteristics, treatment information, and outcome data were analyzed using univariate analyses. RESULTS: A total of 75 PED procedures were analyzed. There was no significant difference in major complications between the PED classic and PED flex. However, those treated using the Marksman microcatheter were more likely to have a major complication (periprocedural hemorrhage or ischemic event; 16.6% vs. 0%, p = 0.0248) than those treated with the Phenom microcatheter. Within the PED flex cohort, all major complications were associated with the Marksman microcatheter (p = 0.0289). CONCLUSIONS: The present study does not replicate significantly fewer complications with PED flex but demonstrates a significant reduction in complications with the Phenom microcatheter. Ultimately, this suggests multiple factors are involved in achieving positive outcomes and low complication rates in PED treated unruptured cerebral aneurysms.

Intraosseous Cannulation of a Calvarial Diploic Vein for Embolization of a Symptomatic Dural Arteriovenous Fistula: A Technical Case Report.

BACKGROUND AND IMPORTANCE: Dural arteriovenous fistulas (DAVFs) may present unique challenges for treatment depending on the anatomy and pattern of venous drainage. If endovascular techniques are to be employed, the DAVF must be amenable to transvenous or transarterial therapy. When access of peripheral vasculature does not provide a straightforward path, less conventional options may be available. This case highlights a novel, technically simple, and effective approach for the treatment of a subset of DAVFs, with venous drainage through calvarial diploic veins, that would make endovascular treatment otherwise challenging or impossible. CLINICAL PRESENTATION: We present a case of a 66-yr-old female patient who was diagnosed with a symptomatic DAVF located along the sphenoid ridge with a large intraosseous channel containing the draining vein of the fistula. This lesion was successfully treated with transcranial endovascular embolization via direct intraosseous cannulation of the calvarial diploic vein. This novel approach obviated the need for a full-thickness craniotomy, afforded only minimal bone loss, and preserved the integrity of the dura. A 3-mo follow-up angiogram confirmed complete cure of the DAVF with no residual arteriovenous shunt. At 20 mo postembolization, the patient was symptom free, with no reported neurologic deficits. Complete diagnostic work-up, treatment planning in a multidisciplinary environment, and a novel approach for endovascular embolization utilizing a hybrid operating suite played key roles in the successful implementation of this technique. CONCLUSION: This is the first report of direct intraosseous cannulation of a calvarial diploic vein for successful transcranial endovascular embolization of a symptomatic DAVF.

Patterns, Predictors, and Outcomes of Postprocedure Delayed Hemorrhage Following Flow Diversion for Intracranial Aneurysm Treatment.

OBJECTIVE: To evaluate patterns, predictors, and outcomes of postprocedure delayed hemorrhage (PPDH) following flow diversion therapy for intracranial aneurysm treatment. METHODS: From 2012 to 2016, 50 patients with 52 aneurysms were treated with the Pipeline embolization device. Device placement was performed as a standalone therapy or with adjunctive coil embolization. Patients underwent dual antiplatelet therapy for 6 months after treatment. Medical comorbidities; aneurysm traits; and treatment factors, including platelet function testing, were studied. Statistical analysis was performed using cross-tabulation. RESULTS: Six PPDHs (12%) occurred 2-16 days (mean 6.8 days) after Pipeline placement, manifesting as 1 of 2 distinct patterns: convexity subarachnoid hemorrhage (cSAH) (n = 4) or lobar intraparenchymal hemorrhage (IPH) (n = 2). All PPDHs occurred ipsilateral to the device; 1 IPH occurred ipsilateral but in a different arterial territory. PPDH occurred in both treated anterior communicating artery aneurysms. Cases of PPDH demonstrated on average lower P2Y12 reaction unit values at the time of treatment. Platelet function testing at the time of hemorrhage was consistently hypertherapeutic. Patients with cSAH had only minimal worsening of modified Rankin Scale score at the time of discharge, whereas the 2 patients with IPH experienced significant deterioration. CONCLUSIONS: PPDH is a poorly understood complication following flow diversion therapy that can result in significant morbidity. In our experience, nonaneurysmal cSAH does not result in poor clinical outcomes, whereas IPH leads to long-term deficits or death. As previously suggested, there appears to be a correlation between low P2Y12 reaction unit values and PPDH.

Dural sinus stenting for idiopathic intracranial hypertension: factors associated with hemodynamic failure and management with extended stenting.

BACKGROUND: Some patients undergoing dural sinus stenting for idiopathic intracranial hypertension (IIH) develop clinical and hemodynamic failure (recurrence of the pressure gradient) owing to stent-adjacent stenosis. OBJECTIVE: To characterize factors associated with hemodynamic failure, and to describe outcomes of patients after repeat stenting. MATERIALS AND METHODS: We reviewed the initial and follow-up clinical, venographic, and hemodynamic data in 39 patients with IIH treated over 17 years with stenting. Thirty-two had follow-up angiographic and hemodynamic data at 1-99 months (mean 27.6, median 19.5 months). Eight patients were treated with 12 repeat stenting procedures, including extended stenting into the superior sagittal sinus (SSS). RESULTS: All patients had an initial successful hemodynamic result with the pressure gradient reduced from 10-43 to 0-7 mm Hg. 10/32 patients (31.3%), all women, developed new stenoses in the transverse sinus or posterior SSS above the stent with a recurrent pressure gradient. 7/9 patients with pure extrinsic stenosis of the transverse-sigmoid junction pre-stenting developed new stenoses and hemodynamic failure. All patients with hemodynamic failure who were restented had early and mid-term documented hemodynamic success at 1.7-50 months. They were free from papilledema at 3.8-50 months after the last restenting, and 11.5-99.5 months after initial stent placement (mean 45.3, median 38.5 months). CONCLUSIONS: Pure extrinsic compression of the transverse-sigmoid junction and female gender were strongly associated with hemodynamic failure. Eight patients with hemodynamic failure who were restented had successful control of papilledema, including 4/4 who had extended stenting into the SSS.