Off-label uses of the Pipeline embolization device: a review of the literature

Expanding Indications for Flow Diverters: Distal Aneurysms, Bifurcation Aneurysms, Small Aneurysms, Previously Coiled Aneurysms and Clipped Aneurysms, and Carotid Cavernous Fistulas

Flow diverter devices have gained wide acceptance for the treatment of unruptured intracranial aneurysms. Most studies are based on the treatment of large aneurysms harboring on the carotid syphon. However, during the last years the “off-label” use of these stents has widely grown up even if not supported by randomized studies. This review examines the relevant literature concerning “off-label” indications for flow diverter devices, such as for distal aneurysms, bifurcation aneurysms, small aneurysms, recurrent aneurysms, and direct carotid cavernous fistulas.

Comaneci-Assisted Coiling as a Treatment Option for Acutely Ruptured Wide Neck Cerebral Aneurysm: Case Series of 118 Patients

BACKGROUND

Wide-necked cerebral aneurysms in the setting of acute subarachnoid hemorrhage (SAH) remain difficult to treat with endovascular methods despite recent progress in the neuroendovascular field.

OBJECTIVE

To evaluate the effectiveness and safety of the Comaneci device (Rapid Medical, Israel) in endovascular coil embolization of acutely ruptured, wide-necked sidewall, or bifurcation cerebral aneurysms.

METHODS

We retrospectively reviewed 45 anterior communicating artery, 24 internal carotid artery, 21 middle cerebral artery bifurcation, 15 anterior cerebral artery, and 13 posterior circulation aneurysms, which were treated using Comaneci-assisted coil embolization from August 2017 to January 2019. We evaluated procedural complications, clinical outcomes, and mid-term angiographic follow-up. Immediate and 90 d-clinical outcome and radiological follow-up were obtained in all patients.

RESULTS

Comaneci-assisted coil embolization was performed in 118 acutely ruptured aneurysms. The technique was carried out successfully in all cases. Simultaneous application of 2 separated Comaneci devices was performed in 8/118 cases (6.77%). Periprocedural thromboembolic complications related to the device were seen in 7/118 cases (5.93%) and severe vasospasm of the parent artery after manipulation of the Comaneci device occurred in 5/118 cases (4.2%). The procedural-related morbidity rate was 2.54%, and there was no procedural related mortality. Among the available survivors, angiographic follow-ups were obtained at 3 and 6 mo, and complete aneurysmal obliteration was confirmed in 81/112 (72.3%) and 75/112 (66.9%) cases, respectively. Mid-term follow-up reviewed total recanalization rate of 14.28%.

CONCLUSION

Comaneci-assisted embolization of wide-necked intracranial aneurysms in patients presenting with acute SAH is associated with high procedural safety and adequate occlusion rates. Furthermore, dual antiplatelet therapy can be safely avoided in this patient group.

Pipeline Embolization device for intracranial aneurysms in a large Chinese cohort: factors related to aneurysm occlusion

Background and Purpose:

The Pipeline Embolization Device (PED, Covidien/Medtronic) is widely used to treat intracranial aneurysms. This PED in China post-market multi-center registry study (PLUS) investigated safety and effectiveness of the PED for intracranial aneurysms in the Chinese population.

Methods:

This was a panoramic, consecutive, real-world cohort registry study. Patients treated with PED with or without coils between November 2014 and October 2019 at 14 centers in China were included, and those treated by parent vessel occlusion or other stents were excluded. Study outcomes included angiographic evaluation of aneurysm occlusion, complications, in-stent stenosis, and predictors of aneurysm occlusion. A central committee reviewed all imaging and endpoint events.

Results:

In total, 1171 patients with 1322 intracranial aneurysms were included. The total occlusion rate was 81.4% (787/967) at mean follow-up of 8.96 ± 7.50 months, with 77.1% (380/493) occlusion in the PED alone and 85.9% (407/474) in the PED plus coiling group. On multi-variate analysis, female sex, hyperlipidemia, vertebral aneurysms, PED plus coiling, and blood flow detained to venous phase were significant predictors of aneurysm occlusion. In posterior circulation cohort, there was no variable associated with aneurysm occlusion. In-stent stenosis predictors included current smoking and cerebral sclerosis/stenosis.

Conclusion:

In the largest series on PED of multi-center date of China, data suggest that treatment with the flow-diverting PED in intracranial aneurysms was efficacious. The treatment of PED combined coiling and blood flow detained to venous phase after PED implant were associated with aneurysmal occlusion. The occlusion rate of vertebral aneurysms was higher than other location aneurysms.

Clinical Trial Registration:

ClinicalTrials.gov identifier: NCT03831672.

A Novel Parameter to Predict Supraclinoid Aneurysm Persistence After Flow Diversion with the Pipeline Embolization Device

BACKGROUND

Aneurysm recurrence after Pipeline Embolization Device (PED) placement can be caused by oversizing of the stent as well as poor wall apposition, both of which can lead to elongation. The objective of this study was to assess whether a novel parameter for measuring device elongation based on two-dimensional imaging could be predictive for persistent aneurysm filling after treatment with the PED.

METHODS

A retrospective cohort analysis was initially completed on 41 aneurysms from institution A, examining demographic, aneurysmal, and device measurements. Device measurements, including the ratio of the measured length to the nominal length (ML/NL) of the PED, were taken by reviewers blinded to the primary end point, which was aneurysm occlusion status on 6 month catheter angiogram. Findings were then externally validated against 30 aneurysms (supraclinoid only) from institution B.

RESULTS

Data from institution A showed 61% complete aneurysm occlusion at 6 months, and were lower for aneurysms in the supraclinoid region. For supraclinoid aneurysms alone, combined data from both institutions showed higher rates of nonocclusion with aneurysm neck size >4 mm (P = 0.008) and a trend toward significance in aneurysms with a branch vessel (P = 0.051). The mean ML/NL ratio was significantly larger in the nonoccluded group compared with the occluded group at both institution A (ratio, 1.37 versus 1.10; P < 0.001) and institution B (ratio, 1.36 vs. 1.11; P = 0.002).

CONCLUSIONS

Our data suggest that a novel parameter based on two-dimensional angiography may serve as a rapid technique to measure device elongation and predict occlusion of supraclinoid aneurysms after PED placement.

The Pipeline Embolization Device: Changes in Practice and Reduction of Complications in the Treatment of Anterior Circulation Aneurysms in a Multicenter Cohort

BACKGROUND

The Pipeline Embolization Device (PED; Medtronic, Dublin, Ireland) has become an important tool for the treatment of cerebral aneurysms. Since FDA approval, there are ongoing efforts to increase aneurysm occlusion rates and reduce the incidence of complications.

OBJECTIVE

To assess aneurysm occlusion and complication rates over time.

METHODS

Retrospective analysis of consecutive anterior circulation aneurysms treated with a single PED between 2011 and 2016 at 3 academic institutions in the US was performed. Factors contributing to changes in aneurysm occlusion and complication rates over time were identified and evaluated.

RESULTS

A total of 284 procedures were performed on 321 anterior circulation aneurysms in 284 patients. At a median follow-up of 13 mo (mean 18 mo), complete or near complete occlusion (>90%) was achieved in 85.9% of aneurysms. There was no significant change in aneurysm occlusion rate or procedure length over time. Thromboembolic complication occurred in 8.1% of procedures, and there was a trend toward decreased incidence from 16.3% in 2011/2012 to 3.3% in 2016 (P = .14). Hemorrhagic complications significantly decreased from 8.2% in 2011/2012 to 0 to 1.0% in 2014-2016 (P = .1).

CONCLUSION

We report a notable drop in the rate of hemorrhagic and to a lesser extent thromboembolic complications with increased experience with PED in a multicenter cohort. Multiple factors are believed to contribute to this drop, including the evolved interpretation of platelet function testing, the switching of clopidogrel nonresponders to ticagrelor, and the reduced use of adjunctive coiling.

Cangrelor dose titration using platelet function testing during cerebrovascular stent placement

BACKGROUND

Optimal antiplatelet inhibition is vital during cerebrovascular stenting procedures, yet no standardized recommendation exists for antithrombotic therapy in these scenarios. Cangrelor is an intravenous P2Y12 inhibitor with a favorable pharmacokinetic profile for use during neuroendovascular stenting.

METHODS

A retrospective review of all neuroendovascular patients who underwent stenting between 1 January 2019 and 22 March 2020 and were treated with cangrelor was conducted. Thirty-seven patients met inclusion criteria.

RESULTS

All patients were administered a bolus of 5 mcg/kg of cangrelor followed by a maintenance infusion. Antiplatelet effects of cangrelor were monitored using platelet reactivity units (PRU). Based on the initial PRU, seven patients' doses were adjusted with subsequent PRUs in or near the goal range of 50-150. One patient experienced an acute intraprocedural occlusion likely related to a subtherapeutic PRU which subsequently resolved with cangrelor dose adjustment and intra-arterial tirofiban administration, and one patient experienced a post-procedure stent occlusion which required a thrombectomy and intra-arterial tirofiban administration. No hemorrhagic complications occurred.

DISCUSSION

Cangrelor utilization during neuroendovascular stenting with maintenance doses of <2 mcg/kg/min with dose adjustments based on platelet function testing has not been previously described. Cangrelor presents many advantages compared to standard therapy in patients undergoing stent placement related to its pharmacokinetic profile, rapid onset of action, ease of transition to oral P2Y₁₂ antiplatelet agents, and measurability.

CONCLUSION

Cangrelor is a promising alternative to currently available therapies, especially in patients with a high hemorrhagic risk.

Treatment of Bilateral Giant Fusiform Petrocavernous Aneurysms

Aneurysms of the petrous segment of the internal carotid artery (ICA) are exceedingly rare. They are thought to arise from traumatic, mycotic, or congenital etiologies. We present a case of bilateral giant fusiform aneurysms of the petrocavernous ICA treated with bilateral flow-diverting stent placement. An 18-year-old male presented to our institution with headaches, nausea, vomiting and blurry vision that had been present since the day prior. Visual exam revealed decreased visual acuity bilaterally and a temporal field cut superiorly and inferiorly of the left eye. CT and MR imaging revealed bilateral lesions of the petrous segment of the ICA bilaterally. Catheter angiography demonstrated bilateral giant fusiform aneurysm of the petrocavernous ICA. The patient was treated with aspirin 325 mg and clopidogrel 75 mg orally daily for one week prior to the exam. VerifyNow (Accriva; San Diego, CA) confirmed adequate platelet inhibition. The right ICA was treated first, with a multiple flow-diverting stent construct. No complications were noted and the patient was discharged to home two days later. He was brought back three weeks later, and the left ICA was treated with a multiple flow-diverting stent construct. Again, no complications were noted and the patient was discharged uneventfully. The patient returned for his six-month follow-up angiogram with improvement of his visual acuity and resolution of headaches. However, the patient had ceased taking both anti-platelet medications six weeks prior. Angiography revealed no filling of the aneurysm in the right ICA, however, the left ICA was occluded at the origin. The patient was resumed on daily aspirin 325 mg orally and will have follow-up catheter angiography at 12 months. Petrous segment ICA aneurysms are rare. Most are thought to arise from trauma, infection, or congenital etiologies. These aneurysms are typically fusiform in nature, and can extend into the cavernous segment of the ICA. The natural history of these aneurysms is not well understood given their rarity. Current literature advocates for asymptomatic patients to be treated conservatively given that the natural history is not well known. Treatment is recommended in symptomatic patients, who may present with symptoms of local mass effect or ischemic stroke due to emboli. Endovascular options include flow diverting stent or covered stent placement, coil embolization with or without stent-assistance, or ICA occlusion. Open surgical options include trapping and high-flow bypass. When bilateral lesions are present, the management algorithm must be amended. We elected to treat the asymptomatic side first (right ICA), due to the presence of a significant kink within the aneurysm on the left. Once the right side was treated successfully, the symptomatic side was treated with a multiple stent construct. The patient's six-month angiogram demonstrated occlusion of the left ICA, likely due to non-compliance with antiplatelet medications. This further reiterates the need for dual-antiplatelet therapy and patient education and compliance with flow diverting stents. We report a rare case of bilateral giant fusiform petrocavernous aneurysms treated with bilateral Pipeline embolization devices in multiple device construct, demonstrating the feasibility and safety of this treatment option for this pathology.

Using overlapping low-profile visualized intraluminal support stent-assisted coil embolization for treating blood blister-like aneurysms of the internal carotid artery

Blood blister-like aneurysm (BBA) of the internal carotid artery (ICA) is highly challenging to treat owing to its variable morphology and tendency for rupture and regrowth. In this study, we attempted to discuss the key techniques for overlapping low-profile visualized intraluminal support (LVIS) stent-assisted coil embolization, which is used for treating BBAs in our center. Clinical characteristics, endovascular treatment details, outcomes, and follow-up results of 13 patients with BBA treated at our center were retrospectively evaluated in this study. Overlapping LVIS stent-assisted coil embolization was successfully performed in all 13 patients of ruptured BBAs located in the ICAs. Recurrence of aneurysm was observed in 4 cases (30.8%) during the angiographic follow-up; in 2 of these cases, spontaneous healing was observed after discontinuation of antiplatelet therapy. Further, 2 patients with recurrence underwent endovascular treatment with complete obliteration of the aneurysm in one and occlusion of the parent artery after Onyx embolization and stent placement in the other. The overall obliteration rate of the BBAs was 92.3% (12/13). One patient (7.7%) developed intraoperative rupture of the aneurysm with coils protruding outside; however, no severe hemorrhage or neurological dysfunction occurred owing to timely embolization. Overlapping LVIS stent-assisted coil embolization is effective for management of BBA of the ICA. Appropriate adjustment in antiplatelet therapy may improve healing in recurrent cases.

Cerebral aneurysm treatment trends in National Inpatient Sample 2007–2016: endovascular therapies favored over surgery

Background

Flow modulation is the newest endovascular technique for treatment of cerebral aneurysms.

Objective

To investigate changes in aneurysm treatment practice patterns in the USA.

Methods

From the 2007 to 2016, the National Inpatient Sample databases, hospital discharges associated with unruptured aneurysms (UA), and/or ruptured aneurysms (RA) having undergone surgical clipping (SC) and/or endovascular treatments (EVT) were identified using the International Classification of Diseases codes. Patient demographics, hospital characteristics, and clinical outcomes were reviewed. Five year subgroup analyses were performed for treatment differences.

Results

A total of 39 282 hospital discharges were identified with a significant increase in EVT (UA: SC n=7847 vs EVT n=12 797, p<0.001; RA: SC n=8108 vs EVT n=10 530, p<0.001). Hospitals in the South demonstrated the most significant EVT use regardless of aneurysm status (UA: SC n=258.5±53.6 vs EVT n=480.7±155.8, p<0.001; RA: SC n=285.6±54.3 vs EVT n=393.3±102.9, p=0.003). From 2007 to 2011, there was no significant difference in the mean number of cases for the treatment modalities (UA: SC n=847.4±107.7 vs EVT n=1120.4±254.1, p=0.21; RA: SC n=949.4±52.8 vs EVT n=1054.4±219.6, p=0.85). Comparatively, from 2012 to 2016, significantly more UA and RA were treated endovascularly (UA: SC n=722.0±43.4 vs EVT n=1439.0±419.2, p<0.001; RA: SC n=672.2±61.4 vs EVT n=1051.6±330.2, p=0.02).

Conclusions

As technological innovations continue to advance the neuroendovascular space, the standard of care for treatment of cerebral aneurysms is shifting further towards endovascular therapies over open surgical approaches in the USA.

The Evolution of Flow-Diverting Stents for Cerebral Aneurysms; Historical Review, Modern Application, Complications, and Future Direction

In spite of the developing endovascular era, large (15–25 mm) and giant (>25 mm) wide-neck cerebral aneurysms remained technically challenging. Intracranial flow-diverting stents (FDS) were developed to address these challenges by targeting aneurysm hemodynamics to promote aneurysm occlusion. In 2011, the first FDS approved for use in the United States market. Shortly thereafter, the Pipeline of Uncoilable or Failed Aneurysms (PUFS) study was published demonstrating high efficacy and a similar complication profile to other intracranial stents. The initial FDA instructions for use (IFU) limited its use to patients 22 years old or older with wide-necked large or giant aneurysms of the internal carotid artery (ICA) from the petrous segment to superior hypophyseal artery/ophthalmic segment. Expanded IFU was tested in the Prospective Study on Embolization of Intracranial Aneurysms with PipelineTM Embolization Device (PREMIER) trial. With further post-approval clinical data, the United States FDA expanded the IFU to include patients with small or medium, wide-necked saccular or fusiform aneurysms from the petrous ICA to the ICA terminus. However, IFU is more restrictive in South Korea than in United States. Several systematic reviews and meta-analyses have sought to evaluate the overall efficacy of FDS for the treatment of cerebral aneurysms and consistently identify FDS as an effective technique for the treatment of aneurysms broadly with complication rates similar to other traditional techniques. A growing body of literature has demonstrated high efficacy of FDS for small aneurysms; distal artery aneurysms; non-saccular aneurysms posterior circulation aneurysms and complication rates similar to traditional techniques. In the short interval since the Pipeline Embolization Device was first introduced, FDS has been firmly entrenched as a powerful tool in the endovascular armamentarium. As new FDS are developed, established FDS are refined, and delivery systems are improved the uses for FDS will only expand further. Researchers continue to work to optimize the mechanical characteristics of the FDS themselves, aiming to optimize deploy ability and efficacy. With expanded use for small to medium aneurysms and posterior circulation aneurysms, FDS technology is firmly entrenched as a powerful tool to treat challenging aneurysms, both primarily and as an adjunct to coil embolization. With the aforementioned advances, the ease of FDS deployment will improve and complication rates will be further minimized. This will only further establish FDS deployment as a key strategy in the treatment of cerebral aneurysms.

Outcomes after coverage of lenticulostriate vessels by flow diverters: a multicenter experience

OBJECTIVE

With the increasing use of flow diversion as treatment for intracranial aneurysms, there is a concomitant increased vigilance in monitoring complications. The low porosity of flow diverters is concerning when the origins of vessels are covered, whether large circle of Willis branches or critical perforators. In this study, the authors report their experience with flow diverter coverage of the lenticulostriate vessels and evaluate their safety and outcomes.

METHODS

The authors retrospectively reviewed 5 institutional databases of all flow diversion cases from August 2012 to June 2018. Information regarding patient presentation, aneurysm location, treatment, and outcomes were recorded. Patients who were treated with flow diverters placed in the proximal middle cerebral artery (MCA), proximal anterior cerebral artery, or distal internal carotid artery leading to coverage of the medial and lateral lenticulostriate vessels were included. Clinical outcomes according to the modified Rankin Scale were reviewed. Univariate and multivariate analyses were performed to establish risk factors for lenticulostriate infarct.

RESULTS

Fifty-two patients were included in the analysis. Postprocedure cross-sectional images were available in 30 patients. Two patients experienced transient occlusion of the MCA during the procedure; one was asymptomatic, and the other had a clinical and radiographic ipsilateral internal capsule stroke. Five patients had transient symptoms without radiographic infarct in the lenticulostriate territory. Two patients experienced in-stent thrombosis, leading to clinical MCA infarcts (one in the ipsilateral caudate) after discontinuing antiplatelet therapy. Discontinuation of dual antiplatelet therapy prior to 6 months was the only variable that was significantly correlated with stroke outcome (p < 0.01, OR 0.3, 95% CI 0-0.43), and this significance persisted when controlled for other risk factors, including age, smoking status, and aneurysm location.

CONCLUSIONS

The use and versatility of flow diversion is increasing, and safety data are continuing to accumulate. Here, the authors provide early data on the safety of covering lenticulostriate vessels with flow diverters. The authors concluded that the coverage of these perforators does not routinely lead to clinically significant ischemia when dual antiplatelet therapy is continued for 6 months. Further evaluation is needed in larger cohorts and with imaging follow-up as experience develops in using these devices in more distal circulation.

Mechanism of Action and Biology of Flow Diverters in the Treatment of Intracranial Aneurysms

Flow diverters have drastically changed the landscape of intracranial aneurysm treatment and are now considered first-line therapy for select lesions. Their mechanism of action relies on intrinsic alteration in hemodynamic parameters, both at the parent artery and within the aneurysm sac. Moreover, the device struts act as a nidus for endothelial cell growth across the aneurysm neck ultimately leading to aneurysm exclusion from the circulation. In silico computational analyses and investigations in preclinical animal models have provided valuable insights into the underlying biological basis for flow diverter therapy. Here, we review the present understanding pertaining to flow diverter biology and mechanisms of action, focusing on stent design, induction of intra-aneurysmal thrombosis, endothelialization, and alterations in hemodynamics.

Carotid-Cavernous Fistula After Transsphenoidal Surgery: A Rare but Challenging Complication

BACKGROUND

Carotid-cavernous fistula (CCF) is a rare complication after transsphenoidal surgery.

METHODS

The aim of this article is to report a case of CCF after the endoscopic resection of a growth hormone secreting pituitary microadenoma, and to discuss and review all the cases of CCF secondary to transsphenoidal procedures described in literature.

RESULTS

A patient aged 74 years was operated for a growth hormone pituitary microadenoma through an endoscopic transsphenoidal surgery. During the procedure, a copious bleeding from the left cavernous sinus was managed with hemostatic material. A direct CCF was diagnosed and managed with transvenous and transarterial coiling. A complete exclusion of the fistula was possible, and the patency of the internal carotid artery was maintained. A total of 9 other cases have been reported. A transsphenoidal approach was performed for sellar tumors in 6 cases, and for chronic sinusitis in 2 cases. In 7 cases, intraoperative hemorrhage was reported, which could be controlled in 5 cases. The postoperative diagnosis of CCF was immediate in 5 cases. Patients presented with persistent bleeding after nasal unpacking or later with chemosis and proptosis. Cerebral angiography was the gold standard for the diagnosis. Eight cases were successfully treated through endovascular techniques with no recurrence observed at follow-up (mean of 15 months). No major neurologic complications were observed.

CONCLUSIONS

CCF should be suspected with every abnormal bleeding after transsphenoidal surgeries, even when the symptoms are mild. Diagnostic arteriography and endovascular treatment represent the mainstay of the management, and an early diagnosis strongly improves the prognosis.

Pipeline embolization for an iatrogenic intracranial internal carotid artery pseudoaneurysm after transsphenoidal pituitary tumor surgery: Case report and review of the literature

Intracranial pseudoaneurysms are uncommon and among the most difficult lesions to treat with surgery or endovascular means without parent artery sacrifice. Here, we report on a patient who underwent successful treatment using a flow-diverting stent for an iatrogenic intracranial internal carotid artery pseudoaneurysm following a vessel injury after endoscopic pituitary tumor resection via the transsphenoidal approach. A 62-year-old man with a Rathke's cleft cyst presenting with bitemporal hemianopia and progressive decline of left visual acuity underwent endoscopic transsphenoidal pituitary tumor resection. During dura incision, brisk arterial bleeding was encountered from the right internal carotid artery. Immediate packing was performed, and hemostasis was achieved. Three days after the vessel injury, an angiography revealed a pseudoaneurysm (2.9 × 2.1 mm) at the cavernous segment of the right internal carotid artery, which showed enlargement on follow-up magnetic resonance imaging at six days postoperatively. Pipeline embolization was performed nine days after the vessel injury. Angiography performed one month after Pipeline embolization revealed significant stagnation but not complete occlusion of blood flow inside the pseudoaneurysm cavity. Dual antiplatelet therapy was replaced with single antiplatelet therapy. Follow-up angiograms three months after Pipeline embolization confirmed complete obliteration of the pseudoaneurysm and successful endoluminal reconstruction of the damaged vessel. Despite the possibility of short-term bleeding and the need for dual antiplatelet therapy administration for a certain period, the use of flow-diverting stents is a feasible vessel-sparing option in the management of intracranial internal carotid artery pseudoaneurysms resulting from transsphenoidal surgery injuries if intraoperative hemodynamic stability can be achieved with effective packing.

Off-Label Application of Pipeline Embolization Device for Intracranial Aneurysms

PURPOSE

The Pipeline embolization device (PED) is approved in the USA for treating giant and large aneurysms arising from the petrous to superior hypophyseal segments of the internal carotid artery in patients older than 21 years of age. This study investigates off-label PED results in a large cohort.

MATERIALS AND METHODS

Retrospective, single-center review of all patients who had off-label PED surgery.

RESULTS

Sixty-two aneurysms (48 patients) underwent off-label PED treatment from 2012- 2017. There were 44 females and four males (age 21 to 75 years; mean/median, 54.3/55.0 years). The most common presenting symptom was headache (47/62, 75.8%). All aneurysms were in the anterior circulation. Aneurysm size ranged from 1.4 to 25.0 mm (mean/median, 7.6/6.9 mm). Fifty-two aneurysms had post-operative imaging with total/near-complete occlusion of 84.6% (44/52). Aneurysm-based operative near-term complication rate was 9.7% while there were no permanent complications. For aneurysms and headache, 86.7% improved/resolved after embo-surgery, and were four times more likely to have a better clinical outcome (resolved or improved symptoms) after surgery (odds ratio [OR], 4.333; P=0.0325). Left-sided aneurysms had a higher occlusion rate (OR, 20; P=0.0073). Hypertension (OR, 4.2; P=0.0332) and smoking (OR, 7; P=0.0155) were more prone towards aneurysm occlusion. Patients without a family history were 14 times more likely to have favorable imaging outcome (P=0.0405). There is no difference of occlusion rates between untreated and previously treated aneurysms (P=0.6894). Overall, occlusion rate decreased by 14% with an increase of aneurysm size by 1 mm (P=0.0283).

CONCLUSION

For anterior circulation aneurysms, the off-label application of PED is as effective and safe as reported for on-label intracranial aneurysms.

Flow diverters as a scaffold for treating direct carotid cavernous fistulas

Background

Direct carotid–cavernous sinus fistulas (dCCFs) are high flow arteriovenous shunts between the internal carotid artery and the cavernous sinus. Recently, we have used the pipeline embolization device (PED) to treat dCCFs.

Methods

We describe our experience treating patients with dCCFs in whom the PED was placed as the primary treatment modality.

Results

Five patients with dCCFs were treated with PEDs deployed in the ipsilateral internal carotid artery spanning the fistula. All patients also underwent either adjunctive transvenous or transarterial embolization. The PED served both as the primary treatment modality and as a scaffold that facilitated safe and efficacious transvenous embolysate administration by altering the flow dynamics through the fistula and providing a physical barrier that protected the internal carotid artery. No intraoperative or perioperative complications occurred. One of the five patients exhibited complete angiographic resolution of the fistula immediately after the procedure. The remaining four patients experienced complete obliteration of the fistula without additional treatment, which suggests that the PED induced alteration promoted thrombosis of the fistula. Therefore, 100% of patients in this series exhibited complete and durable obliteration of the fistula and complete resolution of symptoms following treatment.

Conclusions

We believe that use of the PED to treat dCCFs may be a safe and efficacious strategy that facilitates parent vessel protection during transvenous embolization. Furthermore, the flow alterations induced by the PED may promote thrombosis of incompletely occluded fistulas. This is the largest reported series of non-iatrogenic dCCFs treated with use of the PED as the primary initial treatment strategy.

Predictors of Clinical Outcome After Treatment of Intracranial Aneurysms with the Pipeline Embolization Device

BACKGROUND

Flow-diverting stents have revolutionized the endovascular treatment of intracranial aneurysms. The purpose of this study is to identify predictors of adverse outcomes associated with the pipeline embolization device (PED).

METHODS

A retrospective analysis of all patients treated with PED at a single high-volume center from January 2014 to September 2018. Patient outcomes, neurologic morbidity/mortality, and other clinical variables were analyzed.

RESULTS

We treated 204 aneurysms in 170 patients with PED. Mean length of follow-up was 11 months. Most (181) aneurysms (89%) were located in the anterior circulation, and 23 (11%) were found in the posterior circulation. Most aneurysms were saccular (82%), followed by fusiform (11%), blister (4%), and dissecting pseudoaneurysms (3%). Mean aneurysm size was 8.2 + 5.7 mm with 145 (71%) small aneurysms (≤10 mm), 53 (26%) large aneurysms (between 10 and 25 mm), and 6 (3%) giant aneurysms (≥25 mm). Ninety-two percent of aneurysms were unruptured, and 8% were ruptured. The overall major neurologic morbidity/mortality was 4.7% and 1.8%, respectively. The all-cause mortality was 2.9%. Predictors of neurologic morbidity/mortality included the baseline modified Rankin Scale (P = 0.001), aneurysm neck size (P = 0.003), aneurysm size (P = 0.006), anterior versus posterior location (P = 0.02), and rupture at presentation (0.006). The P2Y12 Reactivity Unit, parent vessel diameter, and patient age did not correlate with adverse events.

CONCLUSIONS

The PED has a satisfactory safety profile in both on- and off-label indications. A poor clinical patient baseline, wider aneurysm neck or larger size, and rupture predict an increased risk of an unfavorable outcome.

Flow diversion treatment of anterior communicating artery region aneurysms

BACKGROUND AND PURPOSE

Reports on flow diversion treatment of aneurysms beyond the Circle of Willis are limited, with few series dedicated to anterior communicating artery region aneurysms. The purpose of this study is to evaluate the safety and effectiveness of the pipeline embolization device in the treatment of anterior communicating artery region aneurysms.

MATERIALS AND METHODS

The neuro-interventional database of a single institution was retrospectively reviewed for anterior communicating artery aneurysms treated with the pipeline embolization device between November 2016 and December 2018. Data on clinical presentation, aneurysm location, type, vessel size, procedural complications, clinical and imaging follow-up were analyzed.

RESULTS

Ten patients with 11 anterior communicating artery aneurysms were included. Procedural success was achieved in 9/10 patients (90%). Flow diversion with the pipeline embolization device yielded occlusion in 100% of patients at 6.5 months. Symptomatic ischemic complications occurred in 2/10 patients (20%); only one of who had permanent symptoms. Hemorrhagic groin complications were encountered in 2/10 patients (20%). There were no deaths and no cerebral hemorrhagic complications.

CONCLUSIONS

Flow diversion therapy may provide a feasible solution for anterior communicating artery region aneurysms that are not amenable to traditional surgical or endovascular modalities.

Flow diversion beyond the circle of Willis: endovascular aneurysm treatment in peripheral cerebral arteries employing a novel low-profile flow diverting stent

Background

Flow diversion (FD) has emerged as superior minimally invasive therapy for cerebral aneurysms. However, aneurysms of small peripheral vessel segments have not yet been adequately treatable. More specifically, currently established devices necessitate large microcatheters which impede atraumatic maneuvering. The Silk Vista Baby (SVB), a novel flow diverter, offers the as yet unique feature of deliverability via a 0.017 inch microcatheter. This study reports our first experience with the SVB in challenging intracranial vessels employing a vessel-specific tailored microcatheter strategy.

Materials and methods

25 patients (27 aneurysms) were prospectively included. A total of 30 SVBs were employed, predominantly targeting demanding aneurysms of the anterior communicating artery complex. The efficacy of the FD was assessed using two-dimensional vector-based perfusion and conventional digital subtraction angiography (DSA) after implantation and at the first follow-up at 3 months. The first follow-up was available in 22 patients.

Results

All devices were implanted without technical or clinical complications. Eleven treatments were performed using the recommended Headway 17. In 14 interventions the even more maneuverable Excelsior SL10 was used, which was previously tried and tested for safety ’in vitro’ as an alternative delivery system. Aneurysmal influx was strongly reduced after implantation. All parent vessels remained patent. 17/27 aneurysms were completely occluded at first follow-up (∼2.7 months), 6/27 aneurysms showed decreased influx or delayed washout and one remained unchanged. In three cases follow-up DSAs are remaining.

Conclusions

SVB provides enhanced controllability in vulnerable segments beyond the circle of Willis. Smaller variants (2.25 mm and 2.75 mm) can safely be implanted via the superiorly navigable Excelsior SL10. Hence, the SVB represents the next evolutionary step in minimally invasive treatment of cerebral aneurysms.

Effect of Fetal Posterior Circulation on Efficacy of Flow Diversion for Treatment of Posterior Communicating Artery Aneurysms: A Multi-Institutional Study

BACKGROUND

Flow diversion (FD) has emerged as an effective treatment modality for aneurysms of the posterior communicating artery (PCOM). Whether or not a fetal posterior circulation (FPC) affects PCOM aneurysm occlusion rates after FD remains undetermined.

METHODS

We performed a retrospective cohort study in which treatment outcomes for FD of PCOM aneurysms from multiple institutions were reviewed. The primary outcome of interest was complete aneurysm occlusion at last follow-up. The presence of a FPC, defined as a PCOM diameter larger than that of the P1 segment, was noted and its relationship to complete aneurysm occlusion was investigated using a Cox proportional hazards model.

RESULTS

There were 49 patients with 49 PCOM aneurysms treated with FD who met inclusion criteria for analysis. A FPC was present in 16 patients (32.7%). Complete aneurysm occlusion was observed in 34 patients (69.4%). Complete occlusion was less common for patients with a FPC (43.7% vs. 81.8%; P = 0.007). For patients with and without a FPC, median time to occlusion was 51 and 6 months, respectively (P = 0.002). Using a multivariable Cox proportional hazards model, a FPC was associated with reduced odds of complete occlusion on last follow-up (risk ratio 0.35, 95% confidence interval 0.14-0.89; P = 0.029).

CONCLUSIONS

Our results indicate reduced efficacy of FD for the treatment of PCOM aneurysms associated with a FPC. These findings may influence treatment selection for aneurysms at this location.

On Flow Diversion: The Changing Landscape of Intracerebral Aneurysm Management

Uptake of flow-diverting technology is rapidly outpacing the availability of clinical evidence. Most current usage is off-label, and the endovascular community is nearer the beginning than the end of the learning curve, given the number of devices in development. A comprehensive overview of technical specifications alongside key outcome data is essential both for clinical decision-making and to direct further investigations. Most-studied has been the Pipeline Embolization Device, which has undergone a transition to the Pipeline Flex for which outcome data are sparse or heterogeneous. Alternative endoluminal devices do not appear to be outperforming the Pipeline Embolization Device to date, though prospective studies and long-term data mostly are lacking, and between-study comparisons must be treated with caution. Nominal technical specifications may be unrelated to in situ performance, emphasizing the importance of correct radiologic sizing and device placement. Devices designed specifically for bifurcation aneurysms also lack long-term outcome data or have only recently become available for clinical use. There are no major studies directly comparing a flow-diverting device with standard coiling or microsurgical clipping. Data on flow-diverting stents are too limited in terms of long-term outcomes to reliably inform clinical decision-making. The best available evidence supports using a single endoluminal device for most indications. Recommendations on the suitability and choice of a device for bifurcation or ruptured aneurysms or for anatomically complex lesions cannot be made on the basis of current evidence. The appropriateness of flow-diverting treatment must be decided on a case-by-case basis, considering experience and the relative risks against standard approaches or observation.

Periprocedural safety and technical outcomes of the new Silk Vista Baby flow diverter for the treatment of intracranial aneurysms: results from a multicenter experience

PURPOSE

The aim of our study was to assess the technical success and the safety of this new low-profile flow diverter Silk Vista Baby (SVB) by evaluating the intraprocedural and periprocedural complication rate.

MATERIAL/METHODS

Clinical, procedural, and angiographic data were analyzed.

RESULTS

41 consecutive patients (28 women; age average 50.5 years) with 43 aneurysms were treated with SVB. Aneurysm sizes were classified by their maximum diameter, with an average size of 9.5 mm (range 2-30 mm). Thirty-four cases were unruptured. five aneurysms previously ruptured, had recurrence after the initial coiling. There were two ruptured cases. Aneurysms' locations were: M1 segment (five cases), M2 segment (three cases), M3 segment (one case), middle cerebral artery (MCA) bifurcation (six cases), carotid-T (two cases), anterior communicating artery/A1/A2 (11 cases), pericallosal artery (four cases), supraclinoid ICA (two cases), PCom (one case), V4 segment (three cases), PCA (three cases), SCA (one case), and PICA (one case). We had five intraprocedural complications which resolved without clinical consequences and three events postprocedural events. Initial occlusion rates were: eight aneurysms (18.6%) were completely occluded, five aneurysms (11.6%) showed near-complete occlusion, four cases (9.3%) showed incomplete filling, and 26 cases (60.4%) showed persisting filling. The mRS score at discharge from the hospital did not change from the admission mRS score.

CONCLUSION

Our study demonstrated that the use of the new low-profile flow diverter, SVB device, for the treatment of intracranial aneurysms is feasible and technically safe.

Aneurysm Characteristics, Study Population, and Endovascular Techniques for the Treatment of Intracranial Aneurysms in a Large, Prospective, Multicenter Cohort: Results of the Analysis of Recanalization after Endovascular Treatment of Intracranial Aneurysm Study

BACKGROUND AND PURPOSE

The Analysis of Recanalization after Endovascular Treatment of Intracranial Aneurysm (ARETA) prospective study aims to determine factors predicting recurrence after endovascular treatment for intracranial aneurysms. In this publication, we review endovascular techniques and present the study population. Characteristics of treated and untreated unruptured aneurysms were analyzed.

MATERIALS AND METHODS

Sixteen neurointerventional departments prospectively enrolled patients treated for ruptured and unruptured intracranial aneurysms between December 2013 and May 2015. Patient demographics, aneurysm characteristics, and endovascular techniques were recorded.

RESULTS

A total of 1289 patients with 1761 intracranial aneurysms, 835 (47.4%) ruptured, were enrolled. Of these, 1359 intracranial aneurysms were treated by endovascular means. Ruptured intracranial aneurysms were treated by coiling and balloon-assisted coiling in 97.8% of cases. In unruptured intracranial aneurysms, the rates of flow diversion, flow disruption, and stent-assisted coiling were 11.6%, 6.9%, and 7.8%, respectively. Rupture status and aneurysm location, neck diameter, and sac size significantly influenced the chosen technique. Treated unruptured intracranial aneurysms, compared with untreated counterparts, had larger aneurysm sacs (7.6 ± 4.0 versus 3.4 ± 2.0 mm; P < 0.001) and neck dimensions (4.1 ± 2.2 versus 2.4 ± 1.3 mm; P < 0.001) and more frequently an irregular form (84.6% versus 44.4%; P < 0.001). Also, its location influenced whether an unruptured intracranial aneurysm was treated.

CONCLUSIONS

Our study provides an overview of current neurointerventional practice in the ARETA cohort. The technique choice was influenced by aneurysm morphology, location, and rupture status. Flow diversion, flow disruption, and stent-assisted coiling were commonly used in unruptured intracranial aneurysms, while most ruptured intracranial aneurysms were treated with coiling and balloon-assisted coiling.

Evaluation of Radiological Features of the Posterior Communicating Artery and Their Impact on Efficacy of Saccular Aneurysm Treatment with the Pipeline Embolization Device: A Case Series Study

BACKGROUND

Posterior communicating artery segment aneurysms are one of the most frequent intracranial aneurysms. Currently, limited data have described the use of the pipeline embolization device (PED) in these aneurysms.

METHODS

We conducted a multicenter retrospective review of 3 prospectively collected databases of patients treated with the PED from January 2013 to December 2017. The primary objective was to assess the efficacy and safety of the PED in the treatment of saccular posterior communicating artery (PComA) aneurysms. We also assessed the effect of anatomical variations on the angiographic and clinical outcomes, including the presence of fetal PComA, vessel origin relationship to the aneurysm, and patency after PED placement.

RESULTS

We identified 57 patients with 60 saccular aneurysms; Their mean age was 60.5 years, and 49 were female (86.0%). A total of 55 aneurysms (91.7%) were unruptured. The median imaging follow-up duration was 8.5 months. Complete occlusion at the last imaging follow-up study was 84.0%. At the last follow-up examination, 94.5% of patients had a modified Rankin scale score of ≤2. The presence of fetal PComA, origin type, and patency during follow-up did have a significant effect on aneurysm occlusion (P = 0.61, P = 0.40, and P = 0.14, respectively).

CONCLUSIONS

PED use for treatment of PComA aneurysms resulted in acceptable occlusion rates. The present study did not find that fetal PComA, its origin, or its patency during follow-up had an effect on aneurysm occlusion.

Comparison of Pipeline Embolization Device Sizing Based on Conventional 2D Measurements and Virtual Simulation Using the Sim&Size Software: An Agreement Study

BACKGROUND AND PURPOSE

The Sim&Size software simulates case-specific intraluminal Pipeline Embolization Device behavior, wall apposition, and device length in real-time on the basis of rotational angiography DICOM data. The purpose of this multicenter study was to evaluate whether preimplantation device simulation with the Sim&Size software results in selection of different device dimensions than manual sizing.

MATERIALS AND METHODS

In a multicenter cohort of 74 patients undergoing aneurysm treatment with the Pipeline Embolization Device, we compared apparent optimal device dimensions determined by neurointerventionalists with considerable Pipeline Embolization Device experience based on manual 2D measurements taken from rotational angiography with computed optimal dimensions determined by Sim&Size experts blinded to the neurointerventionalists' decision. Agreement between manually determined and computed optimal dimensions was evaluated with the Cohen κ. The significance of the difference was analyzed with the Wilcoxon signed rank test.

RESULTS

The agreement index between manual selection and computed optimal dimensions was low (κ for diameter = 0.219; κ for length = 0.149, P < .01). Computed optimal device lengths were significantly shorter (median, 14 versus 16 mm, T = 402, r = -0.28, P < .01). No significant difference was observed for device diameters.

CONCLUSIONS

Low agreement between manually determined and computed optimal device dimensions is not proof, per se, that virtual simulation performs better than manual selection. Nevertheless, it ultimately reflects the potential for optimization of the device-sizing process, and use of the Sim&Size software reduces, in particular, device length. Nevertheless, further evaluation is required to clarify the impact of device-dimension modifications on outcome.

National trends in cerebral bypass surgery in the United States, 2002–2014

OBJECTIVE

Cerebral bypass procedures are microsurgical techniques to augment or restore cerebral blood flow when treating a number of brain vascular diseases including moyamoya disease, occlusive vascular disease, and cerebral aneurysms. With advances in endovascular therapy and evolving evidence-based guidelines, it has been suggested that cerebral bypass procedures are in a state of decline. Here, the authors characterize the national trends in cerebral bypass surgery in the United States from 2002 to 2014.

METHODS

Using the National (Nationwide) Inpatient Sample, the authors extracted for analysis the data on all adult patients who had undergone cerebral bypass as indicated by ICD-9-CM procedure code 34.28. Indications for bypass procedures, patient demographics, healthcare costs, and regional variations are described. Results were stratified by indication for cerebral bypass including moyamoya disease, occlusive vascular disease, and cerebral aneurysms. Predictors of inpatient complications and death were evaluated using multivariable logistic regression analysis.

RESULTS

From 2002 to 2014, there was an increase in the annual number of cerebral bypass surgeries performed in the United States. This increase reflected a growth in the number of cerebral bypass procedures performed for adult moyamoya disease, whereas cases performed for occlusive vascular disease or cerebral aneurysms declined. Inpatient complication rates for cerebral bypass performed for moyamoya disease, vascular occlusive disease, and cerebral aneurysm were 13.2%, 25.1%, and 56.3%, respectively. Rates of iatrogenic stroke ranged from 3.8% to 20.4%, and mortality rates were 0.3%, 1.4%, and 7.8% for moyamoya disease, occlusive vascular disease, and cerebral aneurysms, respectively. Multivariate logistic regression confirmed that cerebral bypass for vascular occlusive disease or cerebral aneurysm is a statistically significant predictor of inpatient complications and death. Mean healthcare costs of cerebral bypass remained unchanged from 2002 to 20014 and varied with treatment indication: moyamoya disease $38,406 ± $483, vascular occlusive disease $46,618 ± $774, and aneurysm $111,753 ± $2381.

CONCLUSIONS

The number of cerebral bypass surgeries performed for adult revascularization has increased in the United States from 2002 to 2014. Rising rates of surgical bypass reflect a greater proportion of surgeries performed for moyamoya disease, whereas bypasses performed for vascular occlusive disease and aneurysms are decreasing. Despite evolving indications, cerebral bypass remains an important surgical tool in the modern endovascular era and may be increasing in use. Stagnant complication rates highlight the need for continued interest in advancing available bypass techniques or technologies to improve patient outcomes.

Pipeline Embolization of an Infectious Basilar Artery Aneurysm in a 2-Year-Old Child: Case Report, Discussion of the Literature and Perioperative Considerations

BACKGROUND AND IMPORTANCE

Flow diversion of intracranial aneurysms has been rarely described in the pediatric population. Here we discuss the technical and perioperative complexities inherent in the flow diversion of an infectious basilar apex aneurysm in a 2-yr-old child with significant medical comorbidities.

CLINICAL PRESENTATION

Following judicious oral administration of dual anti-platelet agents and intra-arterial administration of calcium channel blockers to treat vasospasm, standard endovascular procedures were used to place a flow diverting stent across the neck of a rapidly enlarging infectious aneurysm of the basilar apex.

Following the uncomplicated procedure, the patient demonstrated progressive thrombosis of the previously noted basilar apex aneurysm over a 3-mo period. The patient was therefore felt to be safe to proceed with, and eventually underwent, uncomplicated orthotopic heart transplant.

CONCLUSION

Flow diversion of complex intracranial aneurysms in pediatric patients with significant medical comorbidities is feasible and safe; however, considerations have to be made in the pre- and perioperative care of these patients given the propensity for low-weight and complicated systemic disease processes.

A2, M2, P2 aneurysms and beyond: results of treatment with pipeline embolization device in 65 patients

BACKGROUND

Intracranial aneurysms located in the distal vessels are rare and remain a challenge to treat through surgical or endovascular interventions.

OBJECTIVE

To describe a multicenter approach with flow diversion using the pipeline embolization device (PED) for treatment of distal intracranial aneurysms.

METHODS

Cases of distal intracranial aneurysms defined as starting on or beyond the A2 anterior cerebral artery, M2 middle cerebral artery, and P2 posterior cerebral artery segments were included in the final analysis.

RESULTS

65 patients with distal aneurysms treated with the PED were analyzed. Median aneurysm size at the largest diameter was 7.0 mm, 60% were of a saccular morphology, and 9/65 (13.8%) patients presented in the setting of acute rupture. Angiographic follow-up data were available for 53 patients, with a median follow-up time of 6 months: 44/53 (83%) aneurysms showed complete obliteration, 7/53 (13.2%) showed reduced filling, and 2/53 (3%) showed persistent filling. There was no association between patient characteristics, including aneurysm size (P=0.36), parent vessel diameter (P=0.27), location (P=0.81), morphology (P=0.63), ruptured status on admission (P=0.57), or evidence of angiographic occlusion at the end of the embolization procedure (P=0.49). Clinical outcome data were available for 60/65 patients: 95% (57/60) had good clinical outcome (modified Rankin Scale score of 0-2) at 3 months.

CONCLUSIONS

This large multicenter study of patients with A2, M2, and P2 distal aneurysms treated with the PED showed that flow diversion may be an effective treatment approach for this rare type of vascular pathology. The procedural compilation rate of 7.7% indicates the need for further studies as the flow diversion technology constantly evolves.

Low Yield of Cerebral Angiography in Adequately Occluded Aneurysms After Flow Diversion

BACKGROUND

Flow diversion has emerged as a highly effective treatment for intracranial aneurysms.

OBJECTIVE

To assess the yield of further angiographic follow-up in aneurysms that have achieved adequate occlusion after treatment with the Pipeline Embolization Device (PED; Medtronic Inc, Dublin, Ireland).

METHODS

This is a single-institution, retrospective study. Inclusion criteria were as follows: (1) patients with 1 or more aneurysms treated with PED, (2) available short-term (<12 mo) follow-up digital subtraction angiography (DSA), (3) complete (100%) or near-complete (>95%) occlusion on short-term follow-up DSA, and (4) available further angiographic follow-up (DSA, Magnetic Resonance Angiography (MRA), or Computed Tomography Angiography (CTA)).

RESULTS

A total of 146 patients were identified. Aneurysm size was 8.4 ± 5.1 mm on average. Mean angiographic follow-up time was 29.7 ± 12.2 mo. On short-term follow-up DSA images, 132 (90.4%) had complete aneurysm occlusion and 14 (9.6%) had near-complete occlusion. Four patients (3%) had further DSA follow-up alone, 30 patients (21%) had further DSA and MRA/CTA follow-up, and 112 patients (76%) had further MRA/CTA follow-up alone. On further angiographic follow-up (DSA, MRA, and/or CTA), no patient had a decrease in the degree of aneurysm occlusion (recurrence) or required retreatment. Of the 14 patients with near-complete occlusion on initial DSA images, 7 patients (50%) progressed to complete aneurysm occlusion on further angiographic follow-up.

CONCLUSION

This study did not find any diagnostic yield in repeating cerebral angiography in adequately occluded aneurysms with the PED. We do not recommend repeat angiographic follow-up once aneurysms have achieved complete occlusion with the PED unless clinically warranted.

Apoplectic Silent Crooke Cell Adenoma with Adjacent Pseudoaneurysms: Causation or Bystander?

BACKGROUND

Crooke cell adenomas (CCAs) are rare and potentially aggressive pituitary tumors that often invade the cavernous sinuses. Although clinical presentations of pituitary tumors may include the development of accompanying intracranial aneurysms, there are no documented cases of coexistent intracranial aneurysms and CCAs to date. Herein we describe an apoplectic silent CCA that presented with adjacent cavernous internal carotid artery (ICA) aneurysms.

CASE DESCRIPTION

A 45-year old male patient presented for evaluation of headaches and diplopia. Subsequent imaging series revealed a hemorrhagic pituitary macroadenoma that had invaded the left cavernous sinus and circumferentially involved the ICA. Two pseudoaneurysms were visualized along regions of the ICA directly attached to the tumor. A transnasal transsphenoidal endoscopic approach was used for resection of the tumor, which was identified histologically as a CCA. Endocrine evaluations characterized the tumor as nonfunctional. The patient experienced an excellent recovery with resolution of related symptoms. A pseudoaneurysm was treated with a Pipeline embolization device; however, it persisted at last follow-up.

CONCLUSIONS

CCAs are a poorly characterized and rare pituitary tumor type. In this case, an apoplectic silent CCA invaded the left cavernous sinus and presented with pseudoaneurysms along its involvement of the ICA. Accordingly, the authors speculated that the invasive qualities of this silent corticotroph adenoma may have directly contributed to the development of these aneurysms.

Toward Better Understanding of Flow Diversion in Bifurcation Aneurysms

BACKGROUND AND PURPOSE

Flow diversion is being increasingly used to treat bifurcation aneurysms. Empiric approaches have generally led to encouraging results, and a growing body of animal and ex vivo literature addresses the fate of target aneurysms and covered branches. Our prior investigations highlighted the dynamic nature of metal coverage provided by the Pipeline Embolization Device and suggested strategies for creating optimal single and multidevice constructs. We now address the geometric and hemodynamic aspects of jailing branch vessels and neighboring target aneurysms.

MATERIALS AND METHODS

Fundamental electric and fluid dynamics principles were applied to generate equations describing the relationships between changes in flow and the degree of vessel coverage in settings of variable collateral support to the jailed territory. Given the high complexity of baseline and posttreatment fluid dynamics, in vivo, we studied a simplified hypothetic system with minimum assumptions to generate the most conservative outcomes.

RESULTS

In the acute setting, Pipeline Embolization Devices modify flow in covered branches, principally dependent on the amount of coverage, the efficiency of collateral support, and intrinsic resistance of the covered parenchymal territory. Up to 30% metal coverage of any branch territory is very likely to be well-tolerated regardless of device or artery size or the availability of immediate collateral support, provided, however, that no acute thrombus forms to further reduce jailed territory perfusion.

CONCLUSIONS

Basic hemodynamic principles support the safety of branch coverage during aneurysm treatment with the Pipeline Embolization Device. Rational strategies to build bifurcation constructs are feasible.

Treatment of direct carotid-cavernous fistulas with flow diversion - does it work?

Direct carotid-cavernous fistulas (CCFs) are high flow lesions that can be challenging to treat. A number of recent reports suggest that flow diversion may be a viable treatment option. We present a case of a post-traumatic CCF successfully treated with flow diversion and provide a review of the literature. Our results suggest that flow diversion is a potentially effective treatment option for CCFs and is most successful when used as an adjunctive therapy.

Moderate Sedation for Pipeline Embolization of Posterior Circulation Disease: Technical Note from a Single Center

OBJECTIVE

Flow diversion has been an important addition to endovascular neurosurgery, but its use in the posterior circulation remains controversial. Our goal is to describe the safety and efficacy of moderate sedation during flow diversion for posterior circulation lesions (aneurysms or dissecting pseudoaneurysms).

METHODS

The authors retrospectively reviewed the medical records of all patients who underwent placement of a Pipeline embolization device for a posterior circulation lesion using moderate sedation at a single institution from August 2012 through November 2017. Clinical data and outcomes were evaluated.

RESULTS

Fifteen consecutive patients were identified: 8 female, 7 male (mean age 52.2 ± 16.3 years, range 15-81). Eleven lesions were located in the vertebral artery, 1 in the posterior inferior cerebellar artery, 2 in the posterior cerebral artery, and 1 in the basilar artery. All patients underwent flow diversion with Pipeline embolization devices. One patient experienced an acute occlusion of the basilar artery during the procedure that required revascularization. Mean fluoroscopy time was 35.6 ± 16.5 minutes (range 15.5-75). Mean follow-up time was 12.7 ± 8.8 months (range 3-36). No patient had new neurologic deficits in the perioperative or postoperative period. Conversion to general anesthesia was not required in any case.

CONCLUSIONS

Moderate sedation is safe and feasible in patients undergoing flow diversion for posterior circulation lesions. In addition, its use may allow for more rapid identification of procedural complications, facilitating emergent treatment and decreasing procedure-related morbidity.

Postoperative Anticoagulation After Neurologic Surgery

Management of anticoagulation and antiplatelet medications after neurosurgery can be complex, especially given that these patients have multiple medical comorbidities. In turn, neurosurgical patients are at high risk for the development of venous thromboembolism after surgery, so neurosurgeons must consider the use of pharmacologic prophylaxis. Developments in endovascular neurosurgery have produced therapies that require close management of antiplatelet medications to prevent postoperative complications. Any of these patient populations may need intrathecal access. This article highlights current strategies for managing these issues in the neurosurgical patient population.

Novel Use of Pipeline Stent Device After Inadvertent Microcatheter Rupture During Arteriovenous Fistula Embolization

BACKGROUND

Onyx, a liquid embolic agent, is the mainstay of embolization treatment of arteriovenous malformation or arteriovenous fistula. Microcatheter retention in an embolic cast is a well-known complication. Rupture of catheter with spillage of onyx is a rare phenomenon but can lead to potential occlusion of the parent vessel.

METHODS

We describe a case in which a patient with ruptured arteriovenous fistula experienced rupture of a microcatheter at the proximal part and spillage of onyx on embolization. A Pipeline embolization device (PED) was successfully deployed, and onyx was jailed between the catheter and vessel wall at the third segment of the vertebral artery (V3 segment). A balloon angioplasty helped to complete the opening of the stent.

RESULTS

The procedure was uneventful, and the patient recovered well. Follow-up angiogram revealed patency of posterior circulation. The 6-month follow-up angiogram revealed a patent stent.

CONCLUSIONS

Microcatheter rupture and spillage of onyx during embolization of arteriovenous malformation/arteriovenous fistula is a potential complication, and management should be individualized. The unique close cell design of the PED was successfully used to avoid a potentially life-threatening occlusion of the vertebrobasilar system. To the best of our knowledge, we report for the first time this novel use of PED.

The Blood And Clot Thrombectomy Registry And Collaboration (BACTRAC) protocol: novel method for evaluating human stroke

BACKGROUND

Ischemic stroke research faces difficulties in translating pathology between animal models and human patients to develop treatments. Mechanical thrombectomy, for the first time, offers a momentary window into the changes occurring in ischemia. We developed a tissue banking protocol to capture intracranial thrombi and the blood immediately proximal and distal to it.

OBJECTIVE

To develop and share a reproducible protocol to bank these specimens for future analysis.

METHODS

We established a protocol approved by the institutional review board for tissue processing during thrombectomy (www.clinicaltrials.gov NCT03153683). The protocol was a joint clinical/basic science effort among multiple laboratories and the NeuroInterventional Radiology service line. We constructed a workspace in the angiography suite, and developed a step-by-step process for specimen retrieval and processing.

RESULTS

Our protocol successfully yielded samples for analysis in all but one case. In our preliminary dataset, the process produced adequate amounts of tissue from distal blood, proximal blood, and thrombi for gene expression and proteomics analyses. We describe the tissue banking protocol, and highlight training protocols and mechanics of on-call research staffing. In addition, preliminary integrity analyses demonstrated high-quality yields for RNA and protein.

CONCLUSIONS

We have developed a novel tissue banking protocol using mechanical thrombectomy to capture thrombus along with arterial blood proximal and distal to it. The protocol provides high-quality specimens, facilitating analysis of the initial molecular response to ischemic stroke in the human condition for the first time. This approach will permit reverse translation to animal models for treatment development.

Use of Flow Diversion for the Treatment of Distal Circulation Aneurysms: A Multicohort Study

OBJECTIVE

The safety and efficacy of flow diversion for distal circulation aneurysms of the cerebral vasculature has not been well evaluated. The objective of this study was to assess the use of flow diversion for distal circulation aneurysms (defined as at or beyond the M1, P1, and A1 segments of the middle cerebral artery, posterior cerebral artery, and anterior cerebral artery, respectively) in an international multicenter cohort.

METHODS

Clinical and radiologic records from all patients undergoing flow diversion treatment of distal circulation aneurysms at 3 academic centers (2 in the USA and 1 in Europe) from 2014 until 2017 were retrospectively reviewed.

RESULTS

Forty-six patients (mean age, 58.2 years; 33 women) harboring 46 aneurysms who underwent treatment with either the Pipeline Embolization Device (Medtronic Inc., Dublin, Ireland) or the Flow Re-Direction Endoluminal Device (MicroVention, Tustin, California, USA) were included in these analyses. Thirty-four aneurysms (74%) were located in the anterior circulation and 12 (26%) were located in the posterior circulation. With a mean follow-up of 13.0 months, complete (100%) and near-complete (90%-99%) occlusion was noted in 36 aneurysms (78.2%). Angiographic evidence of side branch or perforator vessel coverage was present in 35 aneurysms (76.1%) but was not associated with failure to occlude at follow-up (P = 0.06). All patients had good functional outcomes after treatment (modified Rankin Scale score 0-2). There were 2 cases (4.3%) of perforator vessel stroke and no hemorrhagic complications.

CONCLUSIONS

Flow diversion for aneurysms beyond the circle of Willis has occlusion rates comparable to alternative treatments and low morbidity. The clinical significance of flow limitation through covered side branches requires further investigation.

‘Plug and pipe’ strategy for treatment of ruptured intracranial aneurysms

Background

Aneurysmal subarachnoid hemorrhage is a potentially devastating condition, and among the first priorities of treatment is aneurysm occlusion to prevent re-hemorrhage. An emerging strategy to treat patients whose aneurysms are not ideal for surgical or endovascular treatment is subtotal coiling followed by flow diversion in the recovery phase or ‘plug and pipe’. However, data regarding the safety and efficacy of this strategy are lacking.

Methods

A retrospective cohort study was performed to evaluate the efficacy and safety of ‘plug and pipe’. All patients with a ruptured intracranial aneurysm intentionally, subtotally treated by coiling in the acute stage followed by flow diversion after recovery, were included. The primary outcome was re-hemorrhage. Secondary outcomes included aneurysm occlusion and functional status. Complications were reviewed.

Results

22 patients were included. No patient suffered a re-hemorrhage, either in the interval between coiling and flow diversion or in follow-up. The median interval between aneurysm rupture and flow diversion was 3.5 months. Roy–Raymond (R-R) class I or II occlusion was achieved in 91% of target aneurysms at the last imaging follow-up (15/22(68%) R-R 1 and 5/22(23%) R-R 2). Complications occurred in 2 (9%) patients, 1 of which was neurological.

Conclusions

Overall, these data suggest that subtotal coiling of ruptured intracranial aneurysms followed by planned flow diversion is both safe and effective. Patients who may most benefit from ‘plug and pipe’ are those with aneurysms that confer high operative risk and those whose severity of medical illness increases the risk of microsurgical clip ligation.

Republished: Recurrence of a totally occluded aneurysm after treatment with a pipeline embolization device

Treatment with a pipeline embolization device (PED) is widely accepted as an excellent option for patients harboring giant, wide neck, saccular intracranial aneurysms. It has been shown to be safe and very effective. We describe a previously unreported case of a large middle cerebral artery aneurysm, related to the carotid tip, that was treated with a PED and coils. The 6 month follow-up angiogram demonstrated complete occlusion of the aneurysm. However, the 9 month angiogram revealed recurrent filling of the aneurysm sac. To our knowledge, this is the first report to describe recanalization of an aneurysm totally occluded on the control angiography after treatment with a PED. Unanswered questions include the mechanism of recanalization and the need for additional control angiograms and MRI following a previous examination revealing total aneurysm occlusion.

Treatment of Small and Tiny Aneurysms Before and After Flow Diversion Era: A Single Center Experience of 409 Aneurysms

OBJECTIVE

To explore whether we should use the Pipeline embolization device (PED) as the primary treatment modality for small and tiny aneurysms at anterior circulation.

METHODS

This retrospective study included 409 cases of small and tiny aneurysms, including aneurysms treated by the PED (n = 77), coiling (n = 51), and stent-assisted coiling (SAC) (n = 281). We also made a comparison regarding the safety and efficacy among these treatment modalities.

RESULTS

A total of 55 patients with 77 small aneurysms were treated with PEDs. Technical success was achieved in 98.4% of procedures. The complete occlusion rate was 75.9% (44/58). Both the morbidity and mortality rates were 1.8%. Comparing the 3 treatment modalities, the technical event rate tended to be the highest in the PED group (4.8% vs. 2.0% and 1.1%; PED vs. Coil vs. SAC; P = 0.100), and the use of a PED neither significantly shortened the procedure duration (127.2 ± 62.8 vs. 115 ± 37.1 and 112.8 ± 40.6 minutes, P = 0.322) nor lowered the complication rate (11.1% vs. 9.8% and 6.1%; P = 0.281). SAC had the highest occlusion rate (75.9% vs. 75.8% and 94.0%; P < 0.001) and lowest morbidity rate (0.8% vs. 4.2% and 1.8%; SAC vs. Coil vs. PED; P = 0.099). Ipsilateral multiple aneurysms were more frequently seen in the PED group (33.8% vs. 3.9% and 3.2%; P < 0.001). Procedure duration tended to be lower in the PED group versus the SAC group (122.7 ± 57.4 vs. 157.5 ± 22.2 minutes; P = 0.060). For these aneurysms, the PED group had the highest occlusion rate (80.0% vs. 50.0% and 66.7%; P = 0.516).

CONCLUSIONS

The PED is an alternative treatment for small and tiny aneurysms. However, SAC remains the safest and most efficient treatment modality. The PED should be reserved for ipsilateral multiple aneurysms.

Recurrence of a totally occluded aneurysm after treatment with a pipeline embolization device

Treatment with a pipeline embolization device (PED) is widely accepted as an excellent option for patients harboring giant, wide neck, saccular intracranial aneurysms. It has been shown to be safe and very effective. We describe a previously unreported case of a large middle cerebral artery aneurysm, related to the carotid tip, that was treated with a PED and coils. The 6 month follow-up angiogram demonstrated complete occlusion of the aneurysm. However, the 9 month angiogram revealed recurrent filling of the aneurysm sac. To our knowledge, this is the first report to describe recanalization of an aneurysm totally occluded on the control angiography after treatment with a PED. Unanswered questions include the mechanism of recanalization and the need for additional control angiograms and MRI following a previous examination revealing total aneurysm occlusion.

Safety and Efficacy of Flow Diverter Treatment for Aneurysm in Small Cerebral Vessels: A Systematic Review and Meta-Analysis

PURPOSE

To clarify the safety and efficacy of flow diverter (FD) treatment for aneurysm in small cerebral vessels, we conducted a systematic review of the literature analyzing perioperative and long-term clinical and angiographic outcomes.

METHODS

A comprehensive review of the up-to-date literature for studies with ≥10 patients related to FD treatment of small vessel aneurysms published was performed. Random-effects meta-analysis was used to pool the following outcomes: complete occlusion, technical procedural success, perioperative mortality, perioperative stroke, procedure-related morbidity and mortality, all complications, long-term mortality, and overall good outcome.

RESULTS

We included 26 noncomparative studies with 572 target aneurysms. The technical procedural success rate was 96% (95% confidence interval [CI] 0.93-1.00). At final follow-up, the complete occlusion rate was 70% (95% CI 0.64-0.76). The all-cause morbidity rate was 20% (95% CI 0.14-0.25). Procedure-related morbidity and mortality rates were 9% (95% CI 0.07-0.12) and 4% (95% CI 0.00-0.08), respectively. Overall long-term good outcome rate was 96% (95% CI 0.93-0.99). In the 3 subgroup analyses, complete occlusion rate of saccular aneurysms was lower than that of nonsaccular aneurysms (55% vs. 73%, respectively; odds ratio 0.40, 95% CI 0.17-0.98, P = 0.04). The procedure-related morbidity rate and the good outcome rate were not significantly different in this subgroup. In the other 2 subgroups in which we compared anterior circulation aneurysms with posterior circulation aneurysms and single FD strategy with overlapped FD strategy, the rates were also not significantly different.

CONCLUSIONS

Our meta-analysis demonstrated that FD treatment of small vessel aneurysms is technically feasible and effective with a high rate of complete occlusion. Although the comorbidities of patients cannot be neglected, the FD approach was associated with an acceptable rate of procedure-related morbidity and a satisfactory rate of overall good outcome.