Parent Artery Straightening after Flow-Diverter Stenting Improves the Odds of Aneurysm Occlusion.

BACKGROUND AND PURPOSE: Intracranial stents for the treatment of aneurysms can be responsible for parent artery straightening, a phenomenon with potential consequences for aneurysmal occlusion. We aimed to evaluate parent artery straightening following flow-diverter stent placement in patients with intracranial aneurysms and explored the association between parent artery straightening and subsequent aneurysm occlusion. MATERIALS AND METHODS: All patients treated with flow-diverter stents for anterior circulation aneurysms located downstream from the carotid siphon between January 2009 and January 2018 were screened for inclusion. Parent artery straightening was defined as the difference (α-ß) in the parent artery angle at the neck level before (α angle) and after flow-diverter stent deployment (ß angle). We analyzed the procedural and imaging factors associated with parent artery straightening and the associations between parent artery straightening and aneurysmal occlusion. RESULTS: Ninety-five patients met the inclusion criteria (n = 64/95 women, 67.4%; mean age, 54.1 [SD, 11.2] years) with 97 flow-diverter stents deployed for 99 aneurysms. Aneurysms were predominantly located at the MCA bifurcation (n = 44/95, 44.4%). Parent artery straightening was found to be more pronounced in patients treated with cobalt chromium stents than with nitinol stents (P = .02). In multivariate analysis, parent artery straightening (P = .04) was independently associated with aneurysm occlusion after flow-diverter stent deployment. CONCLUSIONS: The use of flow-diverter stents for distal aneurysms induces a measurable parent artery straightening, which is associated with higher occlusion rates. Parent artery straightening, in our sample, appeared to be more prominent with cobalt chromium stents than with nitinol stents. This work highlights the necessary trade-off between navigability and parent artery straightening and may help tailor the selection of flow-diverter stents to aneurysms and parent artery characteristics.

Selection of Patients for Treatment of Brain Arteriovenous Malformations by the Transvenous Approach: Relationship with Venous Anatomy and Risk of Hemorrhagic Complications.

BACKGROUND AND PURPOSE: Intracranial hemorrhage represents a severe complication of brain arteriovenous malformation treatment. The aim of this cohort was to report the rate of hemorrhagic complications after transvenous endovascular embolization and analyze the potential angioarchitectural risk factors as well as clinical outcomes. MATERIALS AND METHODS: During an 11-year period, 57 patients underwent transvenous endovascular embolization. All cases of hemorrhagic complications were identified. We analyzed the following variables: sex, age, hemorrhagic presentation, Spetzler-Martin grade, size of the AVM before the transvenous treatment, number of venous collectors, pattern of drainage, presence of dilated veins, and technical aspects. Univariate and multivariate multiple regression analyses were performed to evaluate the potential risk factors for procedure-related hemorrhagic complications. RESULTS: Hemorrhagic complications (either intraprocedural or periprocedural) unrelated to a perforation due to micronavigation occurred in 8 (14.0%) procedures. Significant (mRS > 2) and persistent neurologic deficits were present in 2 (3.5%) patients at 6-month control. Larger nidi, especially >3 cm (P = .03), and a larger number of venous collectors have shown a statistically significant correlation with hemorrhagic complications. Only the number of venous collectors was identified as an independent predictor of hemorrhagic complications in the multivariate analysis (OR, 8.7; 95% confidence interval, 2.2-58.2) (P = .006). CONCLUSIONS: Larger nidus sizes and an increased number of venous collectors may increase the risk of hemorrhagic complications when implementing transvenous endovascular treatment of AVMs. The technique is effective and promising, especially with small nidi and single venous collectors.

Posterior Fossa Dural Arteriovenous Fistulas with Subarachnoid Venous Drainage: Outcomes of Endovascular Treatment.

BACKGROUND AND PURPOSE: Dural AVFs located in the posterior fossa are a rare entity. The objectives of the study were to analyze the anatomy of dural AVFs, their endovascular treatment strategies, and clinical outcomes. MATERIALS AND METHODS: Two centers retrospectively selected patients treated between January 2009 and June 2018 having posterior fossa dural AVFs. We collected patient demographics, clinical presentation, arterial and venous outflow anatomy of the dural AVFs, and treatment outcomes. RESULTS: Twenty-six patients treated endovascularly for posterior fossa dural AVFs, type III, IV, or V, were included. One hundred percent of the dural AVFs were occluded. A transarterial approach was performed in 23 dural AVFs (88.5%); a combined transarterial and transvenous approach, for 2 dural AVFs (7.7%); and a transvenous approach alone, for 1 dural AVF (3.8%). The middle meningeal artery was the most common artery chosen to inject embolic liquid (46%, 12/26). Procedure-related morbidity was 15.4% at 24 hours, 7.7% at discharge, and 0% at 6 months. Procedure-related mortality was 0%. CONCLUSIONS: Endovascular treatment offers high occlusion rates for posterior fossa dural AVFs with low morbidity and mortality rates. The arterial approach is the first-line preferred approach, even if a transvenous or combined approach would be a safe and effective option for patients with favorable anatomy.

Influence of Carotid Siphon Anatomy on Brain Aneurysm Presentation.

BACKGROUND AND PURPOSE: Intracranial aneurysm is a devastating disease of complex etiology that is not fully understood. The purpose of this study was to assess the implications of carotid siphon anatomy for the formation and development of intracranial aneurysms. MATERIALS AND METHODS: Between January 2007 and May 2015, lateral view digital subtraction angiographic images of 692 consecutive patients with intracranial aneurysms treated in our department of interventional neuroradiology were reviewed and had their angles measured. Data on the location, presentation, and size of the lesions were collected and evaluated by multivariate analysis in relation to the measured angles. RESULTS: Of 692 aneurysms, 225 (32.51%) ruptured and 467 (67.49%) unruptured, 218 (31.50%) were in the carotid siphon and 474 (68.50%) were distal to the siphon, and the mean aneurysm size was 7.99 ± 6.95 mm. Multivariate analysis showed an association between angles of >15.40° and rupture (P = .005), postsiphon location (P = .034), and aneurysm size of >1.001 mm (P = .015). Multivariate analysis also showed that every 1-year increase in patient age produced an increase of 1.002 mm in aneurysm size (P = .015). CONCLUSIONS: There was a significant independent direct relation of greater anterior knee angle with intracranial aneurysms located distal to the carotid siphon, larger aneurysms, and greater risk of rupture. These findings may be associated with the hemodynamic interactions of blood flow and the curvature of the carotid siphon.

Tunnel positioning assessment after anterior cruciate ligament reconstruction at 12months: Comparison between 3D CT and 3D MRI. A pilot study.

BACKGROUND: Tunnel positioning assessment is a major issue after anterior cruciate ligament (ACL) reconstruction surgery. Historically, it used plain X-ray and, more recently, CT with 3D reconstruction. MRI is a reliable method of assessing ACL graft integrity and postoperative complications. To our knowledge, there have been no studies of efficacy in tunnel positioning assessment. The aim of this study was to assess the efficacy of 3D MRI in assessing femoral and tibial tunnel positioning after ACL reconstruction. The hypothesis was that 3D MRI sequences with reconstruction are as accurate as 3D CT for tunnel positioning assessment in ACL reconstruction. METHODS: Twenty-two patients who underwent an arthroscopic ACL reconstruction using hamstring graft were included in a prospective study. All patients were examined on 3D CT and 3D MRI at 12months post-surgery. Tunnel positioning was assessed on both imaging systems by a musculoskeletal radiologist and an orthopedic surgeon specialized in knee arthroscopy, both blind to all clinical data. RESULTS: No statistically significant difference was found between 3D CT and 3D MRI on coronal and sagittal reconstructions. For coronal assessment of tibial tunnel orifice, sagittal assessment of tibial tunnel orifice and sagittal assessment of femoral tunnel orifice, P-values ranged from 0.37 to 0.99, 0.051 to 0.64 and 0.19 to 0.59, respectively. For tibial and femoral tunnel angulation, P-values were respectively 0.52 and 0.29. CONCLUSION: 3D MRI is a reliable method to assess femoral and tibia tunnel positioning in ACL reconstruction, compared to 3D CT as gold standard. Indeed, in our opinion 3D MRI could in the future replace CT for ACL reconstruction assessment, concerning not only the meniscus and ligaments but also tunnel position. LEVEL OF EVIDENCE: Level 3; comparative prospective study.

Middle Cerebral Artery Bifurcation Aneurysms Treated by Extrasaccular Flow Diverters: Midterm Angiographic Evolution and Clinical Outcome.

BACKGROUND AND PURPOSE: Flow diverters have been increasingly used lately in off-label, distal intracranial aneurysm treatments. Our aim was to evaluate the effectiveness of flow diverters in the treatment of middle cerebral artery bifurcation aneurysms and to analyze midterm angiographic patterns of regional flow modifications for safety and clinical outcomes. MATERIALS AND METHODS: Consecutive patients treated from January 2010 to December 2014 by the authors by using endovascular flow-diverting stents for MCA bifurcation aneurysms were evaluated retrospectively with prospectively maintained data. All patients had been followed for at least 12 months after treatment, with at least 2 control angiograms; regional flow-related angiographic modifications were registered by using a new angiographic outcome scale for flow diverters. Data were analyzed with emphasis on procedure-related events, angiographic results, and clinical outcome. RESULTS: Fifty-eight patients were included in the study, with 63 MCA bifurcation aneurysms; 13 of these were large and giant. Pretreatment mRS was 0 for 12 patients (20.7%), 1 for 41 (70.7%), and 2 for 5 patients (8.6%). Six-month control revealed mRS 0-2 for 57 (98.3%) patients and 3 for 1 (1.7%) patient. Procedure-related morbidity and mortality were 8.6% (5/58) and 0%, respectively. From 95% of still circulating immediate postprocedure angiographic outcomes, 68% progressed to aneurysm occlusion at 6 months and 95%, to occlusion at 12 months, with a 0% aneurysm rupture rate. CONCLUSIONS: Flow diverters seem to be an effective treatment alternative for complex MCA bifurcation aneurysms, with reasonable complication rates. Longer angiographic follow-ups are needed to assess the morphologic outcome; immediate subtotal occlusions do not seem to be related to rupture.

Head and neck lymphatic malformation and treatment: Clinical study of 23 cases.

OBJECTIVES: Head and neck lymphatic malformation is a rare benign tumor, mainly affecting children under 1 year of age. Total resection is often difficult, and recurrence is frequent. Functional and esthetic sequelae are a major issue. MATERIALS AND METHODS: A single-center retrospective study recruited patients with head and neck lymphatic malformation managed surgically, with or without associated sclerosis by alcohol, bleomycin or aetoxisclerol, between January 1, 2004 and December 31, 2013. Local control, recurrence and complications rates were analyzed, as were swallowing disorder, tracheostomy and impaired phonation. RESULTS: Twenty-three patients, with a mean age of 15.80 years, were included. Location was suprahyoid in 17 cases (73.91%) and infrahyoid in 6 (26.09%). There were 11 macrocysts (47.82%), 2 microcysts (8.70%) and 10 mixed lesions (43.48%). Three patients showed spontaneous resolution; 12 patients (52.17%) underwent a single surgical procedure, 2 (8.7%) multiple procedures, 2 (8.7%) 1 surgical procedure and 1 sclerosis, 2 (8.7%) 1 surgical procedure and multiple scleroses, and 2 (8.7%) multiple procedures and multiple scleroses. The local control rate was 69.56%. There were 8 recurrences (34.78%), all in suprahyoid microcystic or mixed lesions. There were 2 complications (8.7%): 1 severe upper cervical edema following sclerosis of the floor of the mouth, and 1 postsurgical palsy of the marginal mandibular branch of the facial nerve. In 1 case (4.35%), a nasogastric tube was required for 6 days, without tracheostomy. CONCLUSION: Recurrence was frequent, with non-negligible functional and esthetic impact, especially in case of suprahyoid and microcystic lesion.

Visual outcomes with flow-diverter stents covering the ophthalmic artery for treatment of internal carotid artery aneurysms.

BACKGROUND AND PURPOSE: Flow-diverting stents can be used to treat intracranial aneurysms that are not amenable to treatment with coils. We analyzed ophthalmic consequences due to coverage of the origin of the ophthalmic artery by flow-diverting stents for the treatment of internal carotid artery aneurysms. MATERIALS AND METHODS: From April 2009 to April 2013, the clinical and angiographic outcomes of all 28 patients treated for aneurysms with flow-diverting stents covering the origin of the ophthalmic artery were prospectively collected. The origin of the ophthalmic artery in relation to the target aneurysm was classified by using a 4-type classification. A complete ophthalmic examination was performed by a single ophthalmologist 48 hours before and 1 week after covering the ophthalmic artery. RESULTS: Ophthalmic artery patency was normal at the end of endovascular treatment in 24/28 cases (85.7%). With extensive ophthalmic examinations, 11 patients (39.3%) showed new ophthalmic complications. Patients with the ophthalmic artery originating from the aneurysm sac were at high risk for retinal emboli (4/5, 80%). Patients with the ophthalmic artery originating from the inner curve of the carotid siphon were at high risk for optic nerve ischemic atrophy (3/4, 75%). CONCLUSIONS: This prospective study shows that covering the ophthalmic artery with a flow-diverting stent is not without potential complications. Ophthalmic complications can occur but are often not diagnosed. The anatomic disposition of the ophthalmic artery in relation to the carotid siphon and aneurysm should be clearly understood because some configurations have a higher risk. When not required, covering of the ophthalmic artery by flow-diverting stents should be avoided.

Endovascular treatment of middle cerebral artery aneurysms for 120 nonselected patients: a prospective cohort study.

BACKGROUND AND PURPOSE: Multiple technologies have developed the endovascular approach to MCA aneurysms. We assess the safety and the efficacy of a systematic endovascular approach in nonselected patients with MCA aneurysms and determine predictors of treatment outcomes. MATERIALS AND METHODS: We analyzed data collected between January 2007 and January 2012 in a prospective clinical registry. All patients with MCA aneurysms treated by means of the endovascular approach were included. A multivariate analysis was conducted to identify predictors of complications, recanalization, and outcome. RESULTS: A total of 120 patients with 131 MCA aneurysms were included. Seventy-nine patients (65.8%) were treated electively and 41 (34.2%) in the setting of subarachnoid hemorrhage. Thirty-three of 131 aneurysms (25.2%) were treated with simple coiling, 79 aneurysms (60.3%) with balloon-assisted coiling, and 19 aneurysms (14.5%) with stent-assisted coiling. Complications occurred in 13.7% of patients. Stent-assisted coiling was significantly associated with more complications (P = .002; OR: 4.86; 95% CI, 1.60-14.72). At 1 month after treatment, both the permanent morbidity (mRS ≤2) and mortality rates were 3.3%, without any significant difference according to the endovascular techniques. Mean angiographic follow-up was 16.3 months. The rate of recanalization was 15.6% without a statistical difference, according to the technique. Larger aneurysms were a predictor of recanalization (P = .016; OR: 1.183; 95% CI, 1.02-1.36). Retreatment was performed in 10 of 131 aneurysms (7.6%). CONCLUSIONS: Even though stent-assisted coiling significantly increases the risk of procedural complications, endovascular treatment of MCA aneurysms is safe, effective, and provides durable aneurysm closure in nonselected patients.

A novel Swine model to evaluate arterial vessel injury after mechanical endovascular thrombectomy.

Few animal models have been reported to evaluate and compare mechanical endovascular thrombectomy (MET) devices used to treat human ischemic stroke. These models may contribute to the understanding of arterial injury induced by a MET device and potentially by extrapolation to human intracranial arteries. We have developed a novel swine model for MET that allows visualization of the thrombus/device interaction and characterization of mechanical impact on the vessel wall. Twenty superficial femoral arteries were occluded with radiopaque thrombus, and 20 without thrombus were treated with thrombectomy devices. Acute histopathological changes were evaluated. The swine femoral artery, which is comparable in size to the human middle cerebral artery or basilar artery, may offer a useful animal model for the study of histologic alterations induced by MET.

Histopathologic evaluation of arterial wall response to 5 neurovascular mechanical thrombectomy devices in a swine model.

BACKGROUND AND PURPOSE: Five commercial devices are available for mechanical thrombectomy in acute ischemic stroke. This study evaluated and compared the resultant arterial damage from these devices. MATERIALS AND METHODS: Wall damage after 4 wall-contact devices (the Merci retriever, Catch thromboembolectomy system, and Solitaire FR revascularization devices of 4 and 6 mm) and 1 aspiration device (the Penumbra System) was evaluated in the superficial femoral arteries of 20 male swine. Each device was tested with and without intraluminal clot. Twenty control vessels were not subjected to any intervention. Acute histopathologic changes were evaluated. RESULTS: In the device samples, endothelial denudation (72.8 ± 29.4% versus 0.9 ± 1.9%, P < .0001), medial layer edema (52 ± 35.9% versus 18.1 ± 27.8%, P = .004), and mural thrombus (5.3 ± 14.2% versus 0%, P = .05) were found to a greater extent compared with the control samples. The aspiration device provoked more intimal layer (100 ± 79.1% versus 58.8 ± 48.9%, P = .27) and medial layer (75 ± 35.4% versus 46.3 ± 34.8%, P = .13) edema than the wall-contact devices. CONCLUSIONS: All devices caused vascular injuries extending into the medial layer. The aspiration device was associated with more intimal and medial layer edema, compared with the wall-contact devices except for the Catch thromboembolectomy system.

Safety and efficacy of neuroform for treatment of intracranial aneurysms: a prospective, consecutive, French multicentric study.

BACKGROUND AND PURPOSE: Endovascular embolization of wide-neck intracranial aneurysms can be technically challenging, especially when the anatomy is complex. Stent reconstruction of the parent artery is commonly used to treat wide-neck and bifurcated aneurysms. The main objective of this study was to investigate the periprocedural and midterm morbidity and mortality results of this procedure. MATERIALS AND METHODS: SENAT is a consecutive, prospective, multicentric study. Patients with unruptured cerebral aneurysms who underwent endovascular treatment with the Neuroform stent system were recruited and recorded. Technical outcomes and complications were also assessed. The midterm anatomic results were re-evaluated at 12-18 months. RESULTS: A total of 113 stents were used to treat the 107 aneurysms in 107 patients. The mean width of the aneurysm sac was 6.2 mm, and the mean diameter of aneurysm neck was 4.5 mm. The complete occlusion rate postprocedure was 66.4%. The rate of progressive occlusion at 12-18 months was 14%, and the rate of recurrence was 9.7%. The rate of subsequent treatment was 4%. The thromboembolic rate in the periprocedural period was 3.7%, and the rate of delayed TE events was 3%. Overall, the mortality rate at 12-18 months was 1%, and the permanent morbidity rate was 1%. CONCLUSIONS: Stent-assisted coiling with the Neuroform stent system provides a high level of occlusion with low rates of subsequent treatment despite a predominant population of patients with wide-neck aneurysms. Morbidity and thromboembolic rates were comparable to studies investigating stand-alone coiling.

Carotid artery stenting in patients with symptomatic carotid stenosis: a single-center series.

OBJECTIVES: Carotid angioplasty with stenting (CAS) in patients with carotid stenosis (CS) has become more restricted in France especially since the disclosure of such studies as EVA-3S and Stent-supported percutaneous angioplasty of the carotid artery versus endarterectomy (SPACE). This report is of a series of CS cases contraindicated for endarterectomy that underwent CAS at a French center of interventional neuroradiology. PATIENTS AND METHODS: Fifty-five patients with symptomatic CS more than 60% consecutively submitted to CAS between September 2008 and February 2011. The primary endpoint was either death or stroke within 30 days of the procedure; a secondary goal was to identify any possible factors that might have influenced the success and outcome of the intervention. RESULTS: The overall periprocedural stroke/death rate at 30 days was 5.4% (three out of 55 patients), with three non-disabling strokes and no deaths. Twenty-seven patients (49.1%) were treated with a cerebral protection device (CPD). Stent placement was achieved in all cases. Open- and closed-cell stents were implanted in 40 (72.7%) and 15 procedures (27.3%), respectively. Neither the use of a CPD, the carotid stent cell design nor any anatomical or technical factors were associated with a lower risk of stroke or death within 30 days of CAS. CONCLUSION: CAS in symptomatic patients with CS contraindicated for endarterectomy in this selected French series proved feasible and safe, with acceptable levels of morbidity. Use of a CPD, type of stent (open- or closed-cell), and anatomical and technical factors had no influence on the success of the procedure or the outcome within 30 days of the operation.

Angiographic results in intracranial aneurysms treated with inert platinum coils.

This study was designed in an attempt to identify the risk factors that could be significantly associated with angiographic recurrences after selective endovascular treatment of aneurysms with inert platinum coils. A retrospective analysis of all patients with selective endovascular coil occlusion of intracranial aneurysms was prospectively collected from 1999 to 2003. There were 455 aneurysms treated with inert platinum coils and followed by digital subtraction angiography. Angiographic results were classified according Roy and Raymond's classification. Recurrences were subjectively divided into minor and major. The most significant predictors for angiographic recurrences were determined by ANOVAs logistic regression, Cochran-Mantel-Haenszel test, Fisher exact probability. Short-term (4.3 ± 1.4 months) follow-up angiograms were available in 377 aneurysms, middle-term (14.1 ± 4.0 months) in 327 and long-term (37.4 ± 11.5 months) in 180. Recurrences were found in 26.8% of treated aneurysms with a mean of 21 ± 15.7 months of follow-up. Major recurrences needing retreatment were present in 8.8% during a mean period follow-up of 17.9 ± 12.29 months after the initial endovascular treatment. One patient (0.2%) experienced a bleed during the follow-up period. Recurrences after endovascular treatment of aneurysms with inert platinum coils are frequent, but hemorrhages are unusual. Single aneurysm, ruptured aneurysm, neck greater than 4 mm and time of follow-up were risk factors for recurrence after endovascular treatment. The retreatment of recurrent aneurysm decreases the risk of major recurrences 9.8 times. Long-term angiogram monitoring is necessary for the population with significant recurrence predictors.