Short – term outcomes of flow diverter stent (Pipeline) for treatment intracranial aneurysms

Background: With the approval of detachable coils in 1995, endovascular treatment of intracranial aneurysms has become an alternative to surgical clip ligation. Despite the introduction of “modified” coils and advanced techniques such as stent-assisted and balloon-assisted coiling, coil embolization has major limitations because of inability to completely and permanently occlude all aneurysms. As stents were being developed for intracranial use, it was hypothesized that stents could be utilized to divert flow “away” from the aneurysm “back” into the parent vessel, and the concept of “endovascular flow diversion” was proposed. This study aims to report our experience with cerebral aneurysms, which may improve in the treatment with the flow-diverter stent and follow up (1). Methods: This study was conducted in consecutive series of 23 patients. 23 procedures were performed for treating these patients in Ha Noi heart hospital from January 2019 to January 2020. 23 flow diverter stents (Pipeline) were used. Aneurysms morphology, stent patency and cerebral parenchyma before and after intervention were analyzed on images of digital subtraction angiography (DSA), computed tomography (CT) and magnetic resonance (MR). The follow-up data after 3–6 months and 12 months were recorded. Results: In 23 patients (8 men, 15 women), aneurysms of internal carotid artery were mostly common (95.7%), especially in cavernous segments. 13 cases (74%) had saccular aneurysms, and 2 cases (9%) had multiple aneurysms, and only 3 cases (13%) had fusiform aneurysms. Endovascular treatment was successfully performed at rate of 100%.. Mortality and morbidity rates were 0% and 0%, respectively. MRI and MSCT follow-up at 3 months showed complete or incomplete occlusions of aneurysms was 26.1% or 34.8%, respectively. Conclusions: Deployment of flow diverter stent is safe and effective with high rate of successful and low procedural complications

Clinical characteristics, laboratory findings and anatomy of intracranial aneurysms in group of patients treated with flow diverter stent (Pipeline)

Background: This study aim to report our experience with cerebral aneurysm, which may improve in the treatment with the flow diverter stent and follow up. Methods: This study was conducted in consecutive series of 23 patients. 23 procedures were performed for treating these patients in Ha Noi heart hospital from January 2019 to January 2020. 23 flow diverter stents (Pipeline) were used. Aneurysm morphology, stent patency and cerebral parenchyma before and after intervention were analyzed on images of digital subtraction angiography (DSA), computed tomography (CT) and magnetic resonance (MR). The follow-up data after 3–6 months and 12 months were recorded. Results: In 23 patients (8 men, 15 women), aneurysms of internal carotid artery were mostly common (95.7%), especially in cavernous segments. 13 cases (74%) had saccular aneurysms, and 2 cases (9%) had multiple aneurysms, and only 3 cases (13%) had fusiform aneurysms. Endovascular treatment was successfully performed at rate of 100%. Mortality and morbidity rates were 0% and 0%, respectively. MRI and MSCT follow-up at 3 months showed complete or incomplete occlusions of aneurysms was 26.1% or 34.8%, respectively. Conclusion: Unruptured intracranial aneurysms are often detected incidentally on screening imaging in high risk patients, such as women, middle age, estrogen deficiency, and hypertension. The aneurysm is usually small in the cavernous segment of the anterior cerebral artery.

Indirect Flow Diversion for Off-Centered Bifurcation Aneurysms and Distant Small-Vessel Aneurysms, a Retrospective Proof of Concept Study From Five Neurovascular Centers

Background: Treatment of cerebral aneurysms using hemodynamic implants such as endosaccular flow disruptors and endoluminal flow diverters has gained significant momentum during recent years. The intended target zone of those devices is the immediate interface between aneurysm and parent vessel. The therapeutic success is based on the reduction of aneurysmal perfusion and the subsequent formation of a neointima along the surface of the implant. However, a subset of aneurysms–off-centered bifurcation aneurysms involving the origin of efferent branches and aneurysms arising from peripheral segments of small cerebral vessels–oftentimes cannot be treated via coiling or implanting a hemodynamic implant at the neck level for technical reasons. In those cases, indirect flow diversion–a flow diverter deployed in the main artery proximal to the parent vessel of the aneurysm–can be a viable treatment strategy, but clinical evidence is lacking in this regard.Materials and Methods: Five neurovascular centers contributed to this retrospective analysis of patients who were treated with indirect flow diversion. Clinical data, aneurysm characteristics, anti-platelet medication, and follow-up results, including procedural and post-procedural complications, were recorded.Results: Seventeen patients (mean age: 60.5 years, range: 35–77 years) with 17 target aneurysms (vertebrobasilar: n = 9) were treated with indirect flow diversion. The average distance between the flow-diverting stent and the aneurysm was 1.65 mm (range: 0.4–2.4 mm). In 15/17 patients (88.2%), perfusion of the aneurysm was reduced immediately after implantation. Follow-ups were available for 12 cases. Delayed opacification (OKM A3: 11.8%), reduction in size (OKM B1-3: 29.4%) and occlusion (D1: 47.1%) were observable at the latest investigation. Clinically relevant procedural complications and adverse events in the early phase and in the late subacute phase were not observed in any case.Conclusion: Our preliminary data suggest that indirect flow diversion is a safe, feasible, and effective approach to off-centered bifurcation aneurysms and distant small-vessel aneurysms. However, validation with larger studies, including long-term outcomes and optimized imaging, is warranted.

Vessel wall imaging with advanced flow suppression in the characterization of intracranial aneurysms following flow diversion with Pipeline embolization device

BackgroundHigh-resolution vessel wall MRI (VWI) is increasingly used to characterize intramural disorders of the intracranial vasculature unseen by conventional arteriography.ObjectiveTo evaluate the use of VWI for surveillance of flow diverter (FD) treated aneurysms.Materials and methodsRetrospective study of 28 aneurysms (in 21 patients) treated with a FD (mean 57 years; 14 female). All examinations included VWI and a contemporaneously obtained digital subtraction angiogram. Multiplanar pre- and post-gadolinium 3D, variable flip-angle T1 black-blood VWI was obtained using delay alternating nutation for tailored excitation (DANTE) at 3T. 3D time-of-flight MR angiography (MRA) was also carried out. Images were assessed for in-stent stenosis, aneurysm occlusion, presence and pattern/distribution of aneurysmal or parent vessel gadolinium enhancement.ResultsThe VWI-MRI was performed on average at 361±259 days after the intervention. Follow-up DSA was performed at 338±254 days postintervention. Good or excellent black-blood angiographic quality was recorded in 22/28 (79%) pre-contrast and 21/28 (75%) post-contrast VWI, with no cases excluded for image quality. Aneurysm enhancement was noted in 24/28 (85.7%) aneurysms, including in 79% of angiographically occluded aneurysms and 100% of angiographically non-occluded aneurysms. Enhancement of the stented parent-vessel wall occurred significantly more often when aneurysm enhancement was present (92% vs 33%, p=0.049).ConclusionAdvanced VWI produces excellent depiction of FD-treated aneurysms, with robust evaluation of the parent vessel and aneurysm wall to an extent not achievable with conventional MRI/MRA. Gadolinium enhancement may, however, continue even after enduring catheter angiographic occlusion, confounding interpretation, and requiring cognizance of this potentially prolonged effect in such patients.

Flow Diverter Device for Treatment of Cerebral Aneurysm with Short-Term Follow Up: Two Case Reports

The flow diverter device (FDD) is an important treatment method for cerebral aneurysms, especially for intracranial dissecting aneurysms. This paper is the result of FDD treatment for two cases of vertebral dissecting aneurysm (VADA) patients and short-term follow-up at 3 months. All two cases were targeted for unruptured cerebral aneurysm, and 4-vessel angiography was performed as a follow-up examination for 3 months after receiving the procedure. As result, it was possible to shorten the period of use of antiplatelet drugs. In the case of VADA, there are limitations in general coiling procedures or conventional surgical treatment methods. In that sense, the FDD treatment method can be a very effective alternative treatment of VADA

Clinical impact of Sim & Size® simulation software in the treatment of patients with cerebral aneurysms with flow-diverter Pipeline stents

Objectives This study evaluated the clinical impact of the Sim&Size® simulation software on the endovascular treatment with flow-diverter stents of patients with unruptured saccular intracranial aneurysms. Methods This monocentric retrospective study evaluated a cohort of patients treated with flow-divert stents between June 1, 2014, and December 31, 2019, for cerebral aneurysms. Patients belonged to two groups, patients treated with and without the Sim&Size® simulation software. Univariate, bivariate, and multivariate analyses were used to evaluate the clinical impact of simulation software. Results Out of the 73 interventions involving 68 patients analyzed by the study, 76.7% were simulated using the Sim&Size® simulation software, and 23.3% were not. Patients treated with the simulation software had shorter stent lengths (16.00 mm vs. 20.00 mm p-value = 0.001) and surgical time (100.00 min vs. 118.00 min p-value = 0.496). Also, fewer of them required more than one stent (3.6% vs. 17.6% p-value = 0.079). Three patients belonging to the non-stimulated group presented hemorrhagic complications. Conclusions Using the Sim&Size® simulation software for the endovascular treatment of intracranial aneurysms with pipeline flow-diverter stents reduces the stent length.

Safety and Feasibility of Reconstructing Dissection Tandem Lesions with Flow Diverter Stents during Mechanical Thrombectomy for Acute Ischemic Stroke: A Multicenter Retrospective Case Series

BACKGROUND Patients with acute ischemic stroke due to large vessel occlusion may present with concomitant carotid dissections that make the technical approach for their treatment challenging. The purpose of this study was to determine the safety and feasibility of flow diverter (FD) stents to treat carotid artery dissections in tandem lesions of acute ischemic stroke patients during mechanical thrombectomy. METHODS A retrospective review of all patients in which a carotid artery dissection was treated with an FD during endovascular treatment of acute ischemic stroke between 2018 and 2020 was conducted in 5 high‐volume Comprehensive Stroke Centers. Patient clinical and angiographical characteristics, postoperative outcome, and follow‐up were recorded. RESULTS A total of 12 patients (mean age: 54.18±14.74 years, median Alberta Stroke Program Early CT Score: 10 [interquartile range 9–10]) were included. Successful FD stenting with immediate patency of the dissected segments and successful intracranial recanalization modified thrombolysis in cerebral infarction score 2b‐3 after thrombectomy was achieved in all patients. A good outcome (modified Rankin scale 0–2 at 90 days) was achieved in 66% (8/12) of patients. In 25% (3/12) of patients, an additional self‐expanding carotid stent was used to anchor the FD proximally at the carotid bulb level. Complications included 1 symptomatic intracranial hemorrhage after procedure (24–48 hours) and 2 in‐stent stenoses at follow‐up. CONCLUSIONS In this small case series, the treatment of carotid artery dissection with FD stents was safe and technically feasible during mechanical thrombectomy of acute ischemic stroke patients with tandem lesions and resulted in a high rate of good clinical outcome. These results may provide the basis for designing larger prospective studies to assess the efficacy and safety of FD stents in selected patients with carotid tandem lesions.

Treatment of Unique Bilateral Distal Fusiform Superior Cerebellar Artery Aneurysms with Mini-Flow Diverter Device Implantation: Case Report

Currently, surgical revascularization procedures using intracranial–intracranial (IC-IC) or extracranial–intracranial (EC-IC) bypass and distal clipping or trapping are the valid and rescue treatment modality for extremely rare unilateral distal fusiform superior cerebellar artery (SCA) aneurysms. Yet, in case of bilateral fusiform SCA aneurysms, surgical therapy reaches its limit. Mini-flow diverter devices (FDDs) have only recently become available for treating fusiform aneurysms of such small vessels. We report the unique case of bilateral distal fusiform SCA aneurysms in a 43-year-old man with subarachnoid hemorrhage (Fisher grade IV and World Federation of Neurosurgical Societies [WFNS] grade II) treated with endovascular implantation of bilateral mini-FDDs with excellent outcome and no radiographic signs of infarction. Yet, occlusion of one of the FDDs was found in the follow-up, which again shows the eminent danger of occlusion in case of an implantation of FDDs in such small-caliber vessels, which leaves the discussion about the optimal therapy method open.

Vascular Response on a Novel Fibrin-Based Coated Flow Diverter

Purpose Due to thromboembolic complications and in-stent-stenosis after flow diverter (FD) treatment, the long-term use of dual antiplatelet treatment (DAPT) is mandatory. The tested nano-coating has been shown to reduce material thrombogenicity and promote endothelial cell proliferation in vitro. We compared the biocompatibility of coated (Derivo Heal) and non-coated (Derivo bare) FDs with DAPT in an animal model. Methods Derivo® bare (n = 10) and Derivo® Heal (n = 10) FD were implanted in the common carotid arteries (CCAs) of New Zealand white rabbits. One additional FD, alternately a Derivo bare (n = 5) or Derivo Heal (n = 5), was implanted in the abdominal aorta (AA) for assessment of the patency of branch arteries. Histopathological examinations were performed after 28 days. Angiography was performed before and after FD implantation and at follow-up. Results Statistical analysis of the included specimens showed complete endothelialization of all FDs with no significant differences in neointima thickness between Derivo® bare and Derivo® Heal (CCA: p = 0.91; AA: p = 0.59). A significantly reduced number of macrophages in the vessel wall of the Derivo Heal was observed for the CCA (p = 0.02), and significantly reduced fibrin and platelet deposition on the surface of the Derivo Heal was observed for the AA. All branch arteries of the stented aorta remained patent. Conclusion In this animal model, the novel fibrin-based coated FD showed a similar blood and tissue compatibility as the non-coated FD.