Pressure Cooker Technique for Endovascular Treatment of Spinal Arteriovenous Fistulas: Experience in 15 Cases.

BACKGROUND AND PURPOSE: Spinal arteriovenous fistulas are challenging to cure by endovascular means, with a risk of incomplete occlusion or delayed recurrence. The authors report herein their preliminary experience using the pressure cooker technique for the embolization of spinal arteriovenous fistulas. MATERIALS AND METHODS: Fifteen patients (8 men; mean age, 60.3 years) underwent an endovascular treatment of a spinal arteriovenous fistula (12 dural spinal arteriovenous fistulas and 3 epidural spinal arteriovenous fistulas) in 2 different institutions using the pressure cooker technique. Two microcatheters could be navigated in the segmental artery in all patients using 2 guiding catheters. A proximal plug was achieved with highly concentrated cyanoacrylate ± coils. The liquid embolic agent injected to cure the fistula was diluted cyanoacrylate (n = 11) or ethylene-vinyl alcohol (n = 4). Technical and clinical complications were systematically recorded. Clinical and angiographic outcomes were systematically evaluated at follow-up. RESULTS: One (6.7%) procedure-related complication was recorded, which consisted of a transient radicular deficit, related to nerve root ischemia. Clinical improvement was observed in 10/14 (71%) patients for whom clinical follow-up was available. Complete spinal arteriovenous fistula occlusion on a follow-up angiography was observed in 11/12 patients (91.7%) for whom angiographic follow-up was available. One patient (8.3%) presented with a delayed recurrence at 29 months. CONCLUSIONS: The pressure cooker technique is feasible, with either glue or ethylene-vinyl alcohol, for the embolization of spinal arteriovenous fistulas. Our results suggest the safety and effectiveness of this technique.

Considerations for Antiplatelet Management of Carotid Stenting in the Setting of Mechanical Thrombectomy: A Delphi Consensus Statement.

BACKGROUND AND PURPOSE: There are only few data and lack of consensus regarding antiplatelet management for carotid stent placement in the setting of endovascular stroke treatment. We aimed to develop a consensus-based algorithm for antiplatelet management in acute ischemic stroke patients undergoing endovascular treatment and simultaneous emergent carotid stent placement. MATERIALS AND METHODS: We performed a literature search and a modified Delphi approach used Web-based questionnaires that were sent in several iterations to an international multidisciplinary panel of 19 neurointerventionalists from 7 countries. The first round included open-ended questions and formed the basis for subsequent rounds, in which closed-ended questions were used. Participants continuously received feedback on the results from previous rounds. Consensus was defined as agreement of ≥70% for binary questions and agreement of ≥50% for questions with >2 answer options. The results of the Delphi process were then summarized in a draft manuscript that was circulated among the panel members for feedback. RESULTS: A total of 5 Delphi rounds were performed. Panel members preferred a single intravenous aspirin bolus or, in jurisdictions in which intravenous aspirin is not available, a glycoprotein IIb/IIIa receptor inhibitor as intraprocedural antiplatelet regimen and a combination therapy of oral aspirin and a P2Y12 inhibitor in the postprocedural period. There was no consensus on the role of platelet function testing in the postprocedural period. CONCLUSIONS: More and better data on antiplatelet management for carotid stent placement in the setting of endovascular treatment are urgently needed. Panel members preferred intravenous aspirin or, alternatively, a glycoprotein IIb/IIIa receptor inhibitor as an intraprocedural antiplatelet agent, followed by a dual oral regimen of aspirin and a P2Y12 inhibitor in the postprocedural period.

Antiplatelet Management for Stent-Assisted Coiling and Flow Diversion of Ruptured Intracranial Aneurysms: A DELPHI Consensus Statement.

BACKGROUND AND PURPOSE: There is a paucity of data regarding antiplatelet management strategies in the setting of stent-assisted coiling/flow diversion for ruptured intracranial aneurysms. This study aimed to identify current challenges in antiplatelet management during stent-assisted coiling/flow diversion for ruptured intracranial aneurysms and to outline possible antiplatelet management strategies. MATERIALS AND METHODS: The modified DELPHI approach with an on-line questionnaire was sent in several iterations to an international, multidisciplinary panel of 15 neurointerventionalists. The first round consisted of open-ended questions, followed by closed-ended questions in the subsequent rounds. Responses were analyzed in an anonymous fashion and summarized in the final manuscript draft. The statement received endorsement from the World Federation of Interventional and Therapeutic Neuroradiology, the Japanese Society for Neuroendovascular Therapy, and the Chinese Neurosurgical Society. RESULTS: Data were collected from December 9, 2019, to March 13, 2020. Panel members achieved consensus that platelet function testing may not be necessary and that antiplatelet management for stent-assisted coiling and flow diversion of ruptured intracranial aneurysms can follow the same principles. Preprocedural placement of a ventricular drain was thought to be beneficial in cases with a high risk of hydrocephalus. A periprocedural dual, intravenous, antiplatelet regimen with aspirin and a glycoprotein IIb/IIIa inhibitor was preferred as a standard approach. The panel agreed that intravenous medication can be converted to oral aspirin and an oral P2Y12 inhibitor within 24 hours after the procedure. CONCLUSIONS: More and better data on antiplatelet management of patients with ruptured intracranial aneurysms undergoing stent-assisted coiling or flow diversion are urgently needed. Panel members in this DELPHI consensus study preferred a periprocedural dual-antiplatelet regimen with aspirin and a glycoprotein IIb/IIIa inhibitor.

Low rates of recanalization for wide-necked aneurysms treated with stenting after balloon-assisted coiling: combination of techniques delivers stable and improved results during follow-up.

PURPOSE: In the treatment of wide-necked aneurysms, stenting may be required after balloon-assisted coiling (BAC) for reconstructing the lumen/flow of the parent artery in cases of coil herniation. The potential benefits and complications of both techniques remain unclear when used together. Our aim was to assess the safety and long-term angiographic outcomes of stenting after BAC. METHODS: Retrospective review of 87 unruptured wide necked aneurysms (in 80 patients) treated with BAC and requiring stent placement at the final stage of the procedure due to coil prolapse. Aneurysm characteristics, technical issues, clinical records, and MR results were assessed. Post-treatment and follow-up angiograms were evaluated by two independent reviewers and categorized as "stable," "further thrombosis," or "recanalization." RESULTS: The mean maximum diameter was 9.1 ± 4.7 mm and aspect ratio 1.20 ± 0.47. Complete and near-complete initial occlusion were observed in 53 (60.9%) and 28 (32.2%) of all treated aneurysms, respectively. Angiographic follow-up (80 aneurysms; mean, 34.68 ± 25.26 months) revealed stability and further thrombosis in 92.4% (74/80). Recanalization was observed in six cases (7.5%, 6/83), four of which were retreated. No significantly different outcomes were found in terms of aneurysm size (p = 0.641). Transient and reversible procedure-related complications occurred in eight (9.2%), minor permanent deficits in 2.3%, and major deficits, including death, in four cases (4.6%). CONCLUSION: Our results suggest that treatment of wide-necked aneuryms with stent placement after BAC yields low recanalization rates and enhanced angiographic outcomes in long-term follow-up.

Multicenter initial experience with the EmboTrap device in acute anterior ischemic stroke.

BACKGROUND AND PURPOSE: Mechanical thrombectomy predominantly using stent retrievers effectively restores cerebral blood flow and improves functional outcomes in patients with acute ischemic stroke. We sought to determine the safety and efficacy of mechanical thrombectomy using the EmboTrap device. MATERIALS AND METHODS: We identified 80 consecutive patients from 4 centers with acute ischemic stroke treated with EmboTrap from June 2015 to December 2016. All patients had confirmed large vessel occlusions in the anterior circulation using CT or MR angiography with salvageable tissue. We assessed baseline characteristics and treatment related parameters including onset-to-treatment time, recanalization success (mTICI 2b or greater), complications, and good clinical outcome (mRS 0 to 2). RESULTS: Successful recanalization was achieved in 72 patients (90%). When considering the use of a second thrombectomy device as failure, the EmboTrap successfully recanalized 65 patients (81%), with complete (mTICI 3) recanalization in 40 patients (50%) within 1 or 2 passes. Median procedure time (groin to recanalization) was 35 minutes (8-161 minutes). During the procedure, distal emboli in previously unaffected territories were found in 5 (6%) patients. There were 3 vasospasms (4%) and no vessel perforations. Intracranial hemorrhage on CT at day 1 was found in 18 17 (2321%) patients, none with subarachnoid hemorrhages, and 5 were symptomatic (6%). Good clinical outcome occurred in 4749/68 78 patients (6963%). CONCLUSIONS: In this multicenter retrospective study, the EmboTrap device achieved high recanalization rates, good clinical outcomes and was safe in treating acute stroke patients with large vessel occlusions.

The Role of Hemodynamics in Intracranial Bifurcation Arteries after Aneurysm Treatment with Flow-Diverter Stents.

BACKGROUND AND PURPOSE: Treatment of intracranial bifurcation aneurysms with flow-diverter stents can lead to caliber changes of the distal vessels in a subacute phase. This study aims to evaluate whether local anatomy and flow disruption induced by flow-diverter stents are associated with vessel caliber changes in intracranial bifurcations. MATERIALS AND METHODS: Radiologic images and demographic data were acquired for 25 patients with bifurcation aneurysms treated with flow-diverter stents. Whisker plots and Mann-Whitney rank sum tests were used to evaluate if anatomic data and caliber changes could be linked. Symmetry/asymmetry were defined as diameter ratio 1 = symmetric and diameter ratio <1 = asymmetric. Computational fluid dynamics was performed on idealized and patient-specific anatomies to evaluate flow changes induced by flow-diverter stents in the jailed vessel. RESULTS: Statistical analysis identified a marked correspondence between asymmetric bifurcation and caliber change. Symmetry ratios were lower for cases showing narrowing or subacute occlusion (medium daughter vessel diameter ratio = 0.59) compared with cases with posttreatment caliber conservation (medium daughter vessel diameter ratio = 0.95). Computational fluid dynamics analysis in idealized and patient-specific anatomies showed that wall shear stress in the jailed vessel was more affected when flow-diverter stents were deployed in asymmetric bifurcations (diameter ratio <0.65) and less affected when deployed in symmetric anatomies (diameter ratio ∼1.00). CONCLUSIONS: Anatomic data analysis showed statistically significant correspondence between caliber changes and bifurcation asymmetry characterized by diameter ratio <0.7 (P < .001). Similarly, computational fluid dynamics results showed the highest impact on hemodynamics when flow-diverter stents are deployed in asymmetric bifurcations (diameter ratio <0.65) with noticeable changes on wall sheer stress fields. Further research and clinical validation are necessary to identify all elements involved in vessel caliber changes after flow-diverter stent procedures.

Embolization of Intracranial Dural Arteriovenous Fistulas Using PHIL Liquid Embolic Agent in 26 Patients: A Multicenter Study.

BACKGROUND AND PURPOSE: The introduction of liquid embolic agents has revolutionized endovascular approach to cranial vascular malformations. The aim of the study was to retrospectively assess the efficacy and safety of Precipitating Hydrophobic Injectable Liquid (PHIL), a new nonadhesive liquid embolic agent, in the treatment of patients with cranial dural arteriovenous fistulas. The primary end point was the rate of complete occlusion of dural arteriovenous fistulas. Secondary end points included the incidence of adverse events and clinical status at 3-month follow-up. MATERIALS AND METHODS: This was a retrospective multicenter study. Twenty-six consecutive patients with dural arteriovenous fistulas (de novo or previously treated) treated by injection of PHIL only or with PHIL in combination with other embolization products (such as Onyx or detachable coils) were included in the study. Recruitment started in August 2014 and ended in September 2015. RESULTS: Twenty-two (85%) patients were treated with PHIL only, with 3 patients treated with both PHIL and Onyx, and 1, with both PHIL and coils. Immediate complete angiographic occlusion was achieved in 20 (77%) patients. Of the 6 patients with residual fistulas, 3 were retreated with PHIL and 1 achieved angiographic cure. An adverse event was seen in 1 patient who developed worsening of preexisting ataxia due to acute thrombosis of the draining vein. CONCLUSIONS: PHIL appears to be safe and effective for endovascular treatment of cranial dural arteriovenous fistulas. Short-term angiographic and clinical results are comparable with those of Onyx, with the added advantage of easier preparation and improved homogeneous cast visualization. The use of iodine as a radio-opacifier also produces considerably less artifacts on CT compared with tantalum-based embolic materials.

Impact of age and baseline NIHSS scores on clinical outcomes in the mechanical thrombectomy using solitaire FR in acute ischemic stroke study.

BACKGROUND AND PURPOSE: Age and stroke severity are inversely correlated with the odds of favorable outcome after ischemic stroke. A previously proposed score for Stroke Prognostication Using Age and NIHSS Stroke Scale (SPAN) indicated that SPAN-100-positive patients (ie, age + NIHSS score = 100 or more) do not benefit from IV-tPA. If this finding holds true for endovascular therapy, this score can impact patient selection for such interventions. This study investigated whether a score combining age and NIHSS score can improve patients' selection for endovascular stroke therapy. MATERIALS AND METHODS: The SPAN index was calculated for patients in the prospective Solitaire FR Thrombectomy for Acute Revascularization study: an international single-arm multicenter cohort for anterior circulation stroke treatment by using the Solitaire FR. The proportion with favorable outcome (90-day mRS score ≤2) was compared between SPAN-100-positive versus-negative patients. RESULTS: Of the 202 patients enrolled, 196 had baseline NIHSS scores. Fifteen (7.7%) patients were SPAN-100-positive. There was no difference in the rate of successful reperfusion (Thrombolysis In Cerebral Infarction 2b or 3) between SPAN-100-positive versus -negative groups (93.3% versus 82.8%, respectively; P = .3). Stroke SPAN-100-positive patients had a significantly lower proportion of favorable clinical outcomes (26.7% versus 60.8% in SPAN-100-negative, P = .01). In a multivariable analysis, SPAN-100-positive status was associated with lower odds of favorable outcome (OR, 0.3; 95% CI, 0.1-0.9; P = .04). A higher baseline Alberta Stroke Program Early CT Score and a short onset to revascularization time also predicted favorable outcome in the multivariable analysis. CONCLUSIONS: A significantly lower proportion of patients with a positive SPAN-100 achieved favorable outcome in this cohort. SPAN-100 was an independent predictor of favorable outcome after adjusting for time to treatment and the extent of preintervention tissue damage according to the Alberta Stroke Program Early CT Score.

Effect of hypoxia exposure on the recovery of skeletal muscle phenotype during regeneration.

Hypoxia impairs the muscle fibre-type shift from fast-to-slow during post-natal development; however, this adaptation could be a consequence of the reduced voluntary physical activity associated with hypoxia exposure rather than the result of hypoxia per se. Moreover, muscle oxidative capacity could be reduced in hypoxia, particularly when hypoxia is combined with additional stress. Here, we used a model of muscle regeneration to mimic the fast-to-slow fibre-type conversion observed during post-natal development. We hypothesised that hypoxia would impair the recovery of the myosin heavy chain (MHC) profile and oxidative capacity during muscle regeneration. To test this hypothesis, the soleus muscle of female rats was injured by notexin and allowed to recover for 3, 7, 14 and 28 days under normoxia or hypobaric hypoxia (5,500 m altitude) conditions. Ambient hypoxia did not impair the recovery of the slow MHC profile during muscle regeneration. However, hypoxia moderately decreased the oxidative capacity (assessed from the activity of citrate synthase) of intact muscle and delayed its recovery in regenerated muscle. Hypoxia transiently increased in both regenerated and intact muscles the content of phosphorylated AMPK and Pgc-1α mRNA, two regulators involved in mitochondrial biogenesis, while it transiently increased in intact muscle the mRNA level of the mitophagic factor BNIP3. In conclusion, hypoxia does not act to impair the fast-to-slow MHC isoform transition during regeneration. Hypoxia alters the oxidative capacity of intact muscle and delays its recovery in regenerated muscle; however, this adaptation to hypoxia was independent of the studied regulators of mitochondrial turn-over.

Stent retriever use for retrieval of displaced microcoils: a consecutive case series.

SUMMARY: Coil displacement during endovascular coiling procedures may require coil retrieval in the context of flow limitation or thromboembolic risk. No standard recommended method of coil retrieval exists. We present a consecutive series of 14 patients with displaced coil during aneurysm coiling in whom the complication was effectively managed with the use of a stent retriever system. Two illustrative cases from the 14 are described, and technical notes are detailed regarding use of the technique. The use of stent retrievers presents a simple, safe, and effective choice for removal of prolapsed coils during aneurysm coiling.

Pitfalls in target mRNA quantification for real-time quantitative RT-PCR in overload-induced skeletal muscle hypertrophy.

Quantifying target mRNA using real-time quantitative reverse transcription-polymerase chain reaction requires an accurate normalization method. Determination of normalization factors (NFs) based on validated reference genes according to their relative stability is currently the best standard method in most usual situations. This method controls for technical errors, but its physiological relevance requires constant NF values for a fixed weight of tissue. In the functional overload model, the increase in the total RNA concentration must be considered in determining the NF values. Here, we pointed out a limitation of the classical geNorm-derived normalization. geNorm software selected reference genes despite that the NF values extensively varied under experiment. Only the NF values calculated from four intentionally selected genes were constant between groups. However, a normalization based on these genes is questionable. Indeed, three out of four genes belong to the same functional class (negative regulator of muscle mass), and their use is physiological nonsense in a hypertrophic model. Thus, we proposed guidelines for optimizing target mRNA normalization and quantification, useful in models of muscle mass modulation. In our study, the normalization method by multiple reference genes was not appropriate to compare target mRNA levels between overloaded and control muscles. A solution should be to use an absolute quantification of target mRNAs per unit weight of tissue, without any internal normalization. Even if the technical variations will stay present as a part of the intergroup variations, leading to less statistical power, we consider this method acceptable because it will not generate misleading results.

[New options in the therapeutic management of acute ischaemic stroke. Good results with combined i. v. and i. a. lysis and mechanical thrombectomy]. / Neue Wege bei der Akuttherapie des ischämischen Schlaganfalls. Behandlungserfolge mit kombinierter i. v. und i. a. Lyse sowie mechanischer Thrombektomie.

BACKGROUND: Standard therapy for acute ischaemic stroke is the intravenous thrombolysis with rtPA. A combined therapy with intravenous bridging and consecutive intraarterial thrombolysis and mechanical thrombectomy is a relatively new option in patients with proximal vessel occlusion. PATIENTS AND METHODS: 10 Patients with a CTA proven proximal vessel occlusion in the anterior circulation (ACI, carotis bifurcation, MCA) in CTA were treated with a combined therapy with i. v. and i. a. thrombolysis and thrombectomy with a Solitaire FR stent device. RESULTS: All Patients were recanalized, the NIHSS changed from 15.6 to 3.3. 8 out of 10 patients had nearly no symptoms when dismissed. There were no direct therapeutic complications. CONCLUSION: Combined therapy with i. v. and i. a. thrombolysis and thombectomy with the Solitaire FR stent device is a promising option in patients with acute proximal vessel occlusion in the anterior circulation.