Safety of the APOLLO Onyx delivery microcatheter for embolization of brain arteriovenous malformations: results from a prospective post-market study

BACKGROUND

Catheter retention and difficulty in retrieval have been observed during embolization of brain arteriovenous malformations (bAVMs) with the Onyx liquid embolic system (Onyx). The Apollo Onyx delivery microcatheter (Apollo) is a single lumen catheter designed for controlled delivery of Onyx into the neurovasculature, with a detachable distal tip to aid catheter retrieval. This study evaluates the safety of the Apollo for delivery of Onyx during embolization of bAVMs.

METHODS

This was a prospective, non-randomized, single-arm, multicenter, post-market study of patients with a bAVM who underwent Onyx embolization with the Apollo between May 2015 and February 2018. The primary endpoint was any catheter-related adverse event (AE) at 30 days, such as unintentional tip detachment or malfunction with clinical sequelae, or retained catheter. Procedure-related AEs (untoward medical occurrence, disease, injury, or clinical signs) and serious AEs (life threatening illness or injury, permanent physiological impairment, hospitalization, or requiring intervention) were also recorded.

RESULTS

A total of 112 patients were enrolled (mean age 44.1±17.6 years, 56.3% men), and 201 Apollo devices were used in 142 embolization procedures. The mean Spetzler-Martin grade was 2.38. The primary endpoint was not observed (0/112, 0%). The catheter tip detached during 83 (58.5%) procedures, of which 2 (2.4%) were unintentional and did not result in clinical sequelae. At 30 days, procedure related AEs occurred in 26 (23.2%) patients, and procedure-related serious AEs in 12 (10.7%). At 12 months, there were 3 (2.7%) mortalities, including 2 (1.8%) neurological deaths, none of which were device-related.

CONCLUSION

This study demonstrates the safety of Apollo for Onyx embolization of bAVMs.

CLINICAL TRIAL REGISTRATION

CNCT02378883.

Technical note on endovascular treatment of concomitant carotid occlusion in large vessel occlusion stroke: The "single-cross" technique

BACKGROUND

Emergent large vessel occlusive (ELVO) stroke secondary to underlying carotid occlusive disease is frequently encountered in endovascular ischemic stroke therapy and trials. Up to 29% of all cerebral vascular accidents are attributed to severe carotid occlusive disease, and recent interventional trials have demonstrated this occurrence in 18.6-32.2% of ELVO stroke. We present a novel technique using the stent retriever guide wire to expedite angioplasty and/or stent placement for associated carotid occlusive disease during mechanical thrombectomy of ELVO stroke. This technique utilizes the "waiting time" during stent retriever integration within the thrombus as an opportunity to initiate revascularization of the cervical carotid, using the deployed stent retriever guidewire as an ad hoc rapid exchange wire while the stentriever serves as a potential surrogate distal embolic protection device. We present 23 cases using this novel endovascular approach, which we have called the single-cross technique, as the cervical lesion is only traversed once during therapy.

METHODS

A case series of 23 consecutive patients who underwent a novel endovascular technique for treating tandem ICA origin and intracranial occlusive lesions is presented. Endpoints measured were time to re-perfusion, rates of intracranial hemorrhage and clinical outcomes (mRS at 30 and 90 days).

RESULTS

Average procedure time for revascularizing both the carotid and intracranial lesions was 52 min. A symptomatic ICH rate of 9% was observed. Seventy-four percent of patients had an mRS of 0-2 at follow-up.

CONCLUSIONS

The single-cross technique appears to be a safe and effective option for treating tandem occlusive lesions in the setting of ELVO.

A Prospective Multicenter Trial of the TransForm Occlusion Balloon Catheter: Trial Design and Results

Background and Purpose

Adjunctive treatments like balloon-assisted coil embolization (BACE) and stent-assisted coil embolization play a major role in the treatment of wide-neck and large intracranial aneurysms. The TransForm™ Occlusion Balloon Catheter (TOBC) registry is intended to evaluate the safety, efficacy, and efficiency of BACE using the TOBC.

Method and Study Design

The TOBC registry is a prospective multicenter registry trial. Seven sites in the USA and 1 site in Spain participated and enrolled 81 patients.

Results

The performance and safety of the TOBC was evaluated based on scoring for different variables. Scores were measured using a semiquantitative rating scale (1 = excellent, 5 = poor). The mean scores for these variables were as follows: visibility under fluoroscopy, 1.8; ability to reach the intended site, 1.6; stability during first positioning, 1.5; stability during inflation, 1.6; stability during deflation, 1.6; ability to temporarily stop flow, 1.6; and ability to assist in coil embolization, 1.7. The mean inflation and deflation times were 4.9 and 5.6 s, respectively. Complete obliteration of the aneurysm (Raymond class I) was achieved in 69.4% of the BACE cases. Thrombus formation occurred in 4/81 (4.8%) of the cases. In all cases, the thrombus resolved with medications, no patient suffered an infarction, and an underlying hypercoagulable state from subarachnoid hemorrhage was considered a contributing factor. Vessel rupture occurred in 1/81 (1.2%) of the cases, but was unrelated to TOBC use.

Conclusion

BACE using the TOBC is safe and effective. All variables assessed for performance showed good-to-excellent results.

Interhospital Transfer Before Thrombectomy Is Associated With Delayed Treatment and Worse Outcome in the STRATIS Registry (Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischemic Stroke)

Supplemental Digital Content is available in the text.

Background:

Endovascular treatment with mechanical thrombectomy (MT) is beneficial for patients with acute stroke suffering a large-vessel occlusion, although treatment efficacy is highly time-dependent. We hypothesized that interhospital transfer to endovascular-capable centers would result in treatment delays and worse clinical outcomes compared with direct presentation.

Methods:

STRATIS (Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischemic Stroke) was a prospective, multicenter, observational, single-arm study of real-world MT for acute stroke because of anterior-circulation large-vessel occlusion performed at 55 sites over 2 years, including 1000 patients with severe stroke and treated within 8 hours. Patients underwent MT with or without intravenous tissue plasminogen activator and were admitted to endovascular-capable centers via either interhospital transfer or direct presentation. The primary clinical outcome was functional independence (modified Rankin Score 0–2) at 90 days. We assessed (1) real-world time metrics of stroke care delivery, (2) outcome differences between direct and transfer patients undergoing MT, and (3) the potential impact of local hospital bypass.

Results:

A total of 984 patients were analyzed. Median onset-to-revascularization time was 202.0 minutes for direct versus 311.5 minutes for transfer patients (P<0.001). Clinical outcomes were better in the direct group, with 60.0% (299/498) achieving functional independence compared with 52.2% (213/408) in the transfer group (odds ratio, 1.38; 95% confidence interval, 1.06–1.79; P=0.02). Likewise, excellent outcome (modified Rankin Score 0–1) was achieved in 47.4% (236/498) of direct patients versus 38.0% (155/408) of transfer patients (odds ratio, 1.47; 95% confidence interval, 1.13–1.92; P=0.005). Mortality did not differ between the 2 groups (15.1% for direct, 13.7% for transfer; P=0.55). Intravenous tissue plasminogen activator did not impact outcomes. Hypothetical bypass modeling for all transferred patients suggested that intravenous tissue plasminogen activator would be delayed by 12 minutes, but MT would be performed 91 minutes sooner if patients were routed directly to endovascular-capable centers. If bypass is limited to a 20-mile radius from onset, then intravenous tissue plasminogen activator would be delayed by 7 minutes and MT performed 94 minutes earlier.

Conclusions:

In this large, real-world study, interhospital transfer was associated with significant treatment delays and lower chance of good outcome. Strategies to facilitate more rapid identification of large-vessel occlusion and direct routing to endovascular-capable centers for patients with severe stroke may improve outcomes.

Clinical Trial Registration:

URL: https://www.clinicaltrials.gov. Unique identifier: NCT02239640.

Frequency-domain optical coherence tomography assessment of human carotid atherosclerosis using saline flush for blood clearance without balloon occlusion

FD-OCT is a new imaging technique that allows unprecedented in vivo microlevel assessment of human carotid plaque morphologic patterns and stent-vessel interactions. Prior reports describing the use of this technique have used balloon occlusion of the target vessel or iodinated contrast media to facilitate imaging. We report, for the first time, in vivo FD-OCT imaging of human carotid arteries without the use of iodinated contrast material or balloon occlusion techniques.

Intravascular frequency-domain optical coherence tomography assessment of atherosclerosis and stent-vessel interactions in human carotid arteries

BACKGROUND AND PURPOSE

Carotid artery-related stroke is largely an embolic disease that has been correlated with inflammation, plaque rupture, and thrombus formation in "vulnerable" atherosclerotic plaque. Nevertheless, current guidelines for carotid revascularization in asymptomatic patients rely on the calculation of stenosis for risk assessment, a parameter that has been viewed with increasing skepticism. Intravascular OCT is an imaging technique that offers high axial resolution (10 μm), allowing an unprecedented micron-level assessment of human carotid plaque morphology. This observational article reports the first successful use of the newest iteration of this technology, FDOCT without balloon occlusion to assess human carotid artery disease and carotid stent-vessel interaction in vivo.

MATERIALS AND METHODS

Four patients with asymptomatic carotid artery disease and ambiguous noninvasive and/or angiographic data underwent carotid FDOCT to assess risk and to formulate a treatment strategy.

RESULTS

Findings include the unexpected demonstration of TCFAs, plaque rupture, thrombus, inflammation, and marked tissue prolapse through stent struts in patients without high-risk factors by conventional criteria, as well as low-risk features in a patient with a high-risk noninvasive study. The procedures were performed without safety issues or special accommodations for vessel occlusion.

CONCLUSIONS

The present study demonstrates the technical feasibility of FDOCT in cervical carotid arteries. As such, this technology holds the promise of not only clarifying ambiguous data in individual patients but of providing data that might call for a future paradigm shift in the assessment of asymptomatic carotid artery disease.

The emergency use of endografts in the carotid circulation to control hemorrhage in potentially contaminated fields

We report our experience with the use of endoluminal grafts to control emergency bleeding in two patients with tracheoinnominate fistulas and three patients with carotid blowouts. Systemic infectious complications were not seen. However, rebleeding occurred in one patient, and extensive stent coverage to control bleeding was required in a second. Survival was usually limited by the patient's cancer. There was one long-term survivor without cancer whose tracheostomy was placed for neurologic compromise. A review of the literature for similar cases identified 18 additional endografts placed for carotid blowout and 3 placed for tracheoinnominate fistulas. Overall, infectious complications occurred in only two patients, whereas rebleeding occurred in eight patients. On the basis of these findings, we believe that endografts are useful to control emergency hemorrhage in these two pathologies because treatment is usually palliative, given the poor survival secondary to the underlying disease. However, more extensive graft coverage may be necessary considering the erosive nature of these processes.

Combined transarterial N-butyl cyanoacrylate and coil embolization of direct carotid–cavernous fistulas

✓ The authors report two cases of traumatic carotid–cavernous fistulas treated successfully with combined N-butyl cyanoacrylate glue and coil embolization via a transarterial approach. In both cases complete occlusion of the fistula was achieved, with preservation of the parent carotid artery. Casting of the cavernous sinus with a liquid embolic agent was well tolerated and produced no complications of cranial nerve palsy. This technique provides interventionalists with yet another treatment option in these often complex cases.

Spontaneous intracranial arterial dissection in the young: diagnosis by CT angiography

Background

Spontaneous carotid artery dissections have been rarely reported in children. Diagnosis has traditionally been confirmed by catheter arteriography. More recently diagnosis has been made by magnetic resonance imaging and magnetic resonance angiography; however the sensitivity of these techniques has yet to be determined. The authors are unaware of reports of carotid dissection confirmed by dynamic computed tomography (computerized tomographic arteriography) in the young.

Case presentation

We recently evaluated a fourteen year-old male following the development of transient neurologic symptoms. There was no antecedent illness or trauma. Dynamic computed tomography revealed an intracranial dissection involving the supraclinoid segment of the left internal carotid artery (confirmed by catheter arteriography). Studies for vasculitis, pro-thrombotic states, and defects of collagen were negative.

Conclusion

Spontaneous carotid artery dissection is a potential cause of transient neurological symptoms and ischemic stroke in the pediatric population. Dynamic computed tomography appears to be a reliable diagnostic tool which can lead to early diagnosis.

MRI volumetric and intensity analysis of the cerebellum in Parkinson's disease patients infused with glial-derived neurotrophic factor (GDNF)

BACKGROUND

A recent human therapeutic trial using intraputaminal infusion of glial cell-derived neurotrophic factor (GDNF) in Parkinson's disease (PD) was abruptly terminated, partly due to safety concerns raised by the finding of cerebellar lesions in monkeys given high-dose GDNF.

METHODS

Magnetic resonance images from nine PD patients participating in this trial were analyzed to determine whether subtle volumetric or intensity changes could be detected in the cerebellum or elsewhere following GDNF treatment for over 1 year. Subtraction images were compared to a reference standard deviation map constructed by using identically-processed paired scans from 25 normal adults. In a separate voxel-based group morphometric (VBM) analysis of the same patient images, grey matter intensity was compared between pre and post-GDNF infusion scans using a repeated measures ANOVA with family-wise error threshold of P = 0.10. Two expert readers independently reviewed serial FLAIR images from all patients.

RESULTS

(1) There were no significant cerebellar differences in any of the nine individual PD patients (difference image analysis), (2) there were no significant morphometric differences between pre- and post-GDNF scans (VBM), and (3) there were no signal abnormalities in the cerebellum detected on the FLAIR images in PD patients (clinical scan review).

CONCLUSIONS

In concert with lack of evidence of cerebellar dysfunction on clinical examination, we find no imaging evidence of cerebellar injury in human subjects undergoing chronic intracerebral GDNF infusion.

Interhemispheric lipoma connected to subcutaneous lipoma via lipomatous stalk

Lipomas are rare intracranial lesions and are generally thought to be asymptomatic. The vast majority of intracranial lipomas are viewed as incidental findings on imaging studies and treated conservatively. Intracranial lipomas are frequently accompanied by additional intracranial congenital malformations, but only rarely has an association with subcutaneous lipomas been described. We report an infant with a subgaleal lipoma in the region of the anterior fontanelle connected to a large interhemispheric (pericallosal) lipoma via a tiny lipomatous stalk. Because of this association, infants who present with a subcutaneous lipoma of the scalp might be considered for MR imaging to evaluate for an intracranial component.

Percutaneous sacroplasty for the treatment of sacral insufficiency fractures

OBJECTIVE

The purpose of this article is to illustrate the effectiveness and utility of percutaneous sacroplasty in the treatment of sacral insufficiency fractures. We also outline the technical considerations in performing the procedure.

CONCLUSION

Percutaneous sacroplasty is an effective treatment for sacral insufficiency fractures. Most patients experience significant relief within the first 48 hr.

Imaging of the brain, including diffusion-weighted imaging in methylmalonic acidemia

Methylmalonic acidemia (MMA) is a multifactorial autosomal recessive inborn error of organic acid metabolism, often presenting with neurologic findings. We report the imaging findings in a case of a child with classic neurological and laboratory findings for MMA. Imaging studies demonstrated abnormalities within the basal ganglia, particularly the globi pallidi (GP). Diffusion-weighted abnormalities seen in patients with MMA during an acute episode of metabolic acidosis and at follow-up are discussed. The authors are aware of only one prior report of serial examinations demonstrating resolution of restricted diffusion in the GP. The biochemical and pathophysiologic basis of the imaging findings of MMA are explained.

Stereotactic radiosurgery associated neurotoxicity

Stereotactic radiosurgery (SRS) is an evolving therapeutic modality for well demarcated intracranial lesions. Since the inception of stereotactic radiosurgery the types of parenchymal CNS lesions addressed by this mode of treatment has increased. All modern stereotactic radiosurgical procedures employ several common features. Patients are fitted with a stereotactic head frame or fiducial markers followed by radiographic imaging which allows for external reference points and three-dimensional mapping of the intracranial lesion. Armed with this information a highly conformal treatment plan is developed to deliver a high dose of radiation to a sharply defined target, with rapid dose fall-off outside the lesion volume. While an extremely effective therapeutic option, SRS is not without risk of neurotoxicity, with radiation necrosis being the most commonly recognized complication. The neurotoxic effects of SRS are reviewed and discussed.

Pseudo-subarachnoid hemorrhage: a potential imaging pitfall associated with diffuse cerebral edema

We report CT findings in seven patients with diffuse cerebral edema and increased attenuation in the basilar cisterns resembling subarachnoid hemorrhage. On the basis of autopsy (three cases) and lumbar puncture (four cases) findings, true subarachnoid hemorrhage was reasonably excluded. Pathophysiologic changes that occur with diffuse cerebral edema are explored, with proposed explanations for the appearance of a pseudo-subarachnoid hemorrhage.

Fluoroscopy fade for embolization of vein of Galen malformation

A fluoroscopy fade technique in the embolization of a vein of Galen malformation in a 10-week-old infant is discussed herein. The availability of the fluoroscopy fade function eliminated the necessity of road mapping during the procedure and permitted minimal usage of contrast material and minimal radiation exposure for the patient. Techniques used during the embolization and the benefits of the fluoroscopy fade feature are also described.

Recognition and importance of an infraoptic anterior cerebral artery: case report

Although variations of the anterior cerebral artery (ACA)-anterior communicating artery complex are commonly identified on imaging studies, an infraoptic course of the ACA is exceedingly rare. What is believed to be the first case of an infraoptic course of the ACA discovered with MR angiography and further characterized with conventional angiography is presented. The high prevalence of associated aneurysms and the implications for surgical planning make preoperative recognition of this anomaly critical.

Congenital absence of the internal carotid artery: case reports and review of the collateral circulation

Absence of the internal carotid artery (ICA) is a rare congenital anomaly. The embryology of the ICA and the common collateral pathways associated with its congenital absence are reviewed, with four new cases provided for illustration. While collateral blood flow may allow these patients to remain asymptomatic, two of our patients presented with transient ischemic attacks. Recognition of this anomaly has important implications during planned carotid or transsphenoidal surgery, in thromboembolic disease, and in the surveillance and detection of associated cerebral aneurysms.

Intracranial and spinal MR imaging findings associated with Krabbe's disease: case report

Krabbe's disease is an autosomal recessive leukodystrophy with well-documented intracranial findings on both CT scans and MR images. We herein present what is thought to be the second case of Krabbe's disease with spinal involvement shown on MR images as abnormal contrast enhancement of the lumbosacral nerve roots. The typical intracranial findings of T2 hyperintensity without contrast enhancement were present within the periventricular white matter, but there was no area of abnormal signal intensity or enhancement within the substance of the spinal cord. We briefly review the pathophysiology, clinical presentation, and imaging findings of Krabbe's disease. Spinal abnormalities may precede the onset of brain abnormalities, and MR imaging may be a useful diagnostic tool in cases of Krabbe's disease and other leukodystrophies.

Noninvasive estimation of pulmonary capillary wedge pressure from computed radiography

PURPOSE

This study was undertaken to see if computed radiography (CR) could be used to estimate pulmonary capillary wedge pressure (PCWP).

METHODS

Radiographic measurements of pulmonary artery-bronchus ratios (ABR), cardiomegaly, interstitial edema, alveolar edema, and pleural effusion, obtained from portable CR images of patients admitted to an intensive care unit, were compared to hemodynamic measurements of PCWP. We prospectively predicted a normal PCWP when ABR was < or = 1.0, and an elevated PCWP when ABR was > or = 1.1.

RESULTS

There was a significant difference between mean ABR in those with normal PCWP (1.014 +/- 0.259) and those with elevated PCWP (1.422 +/- 0.234) (p < 0.0001). There was a positive correlation between PCWP and ABR (r = 0.38, r2 = 0.147, p = 0.0001). ABR was 95% sensitive, 86% specific, and 93% accurate in predicting PCWP (p = 0.0001). Cardiomegaly, interstitial edema, alveolar edema, and pleural effusion were not as useful.

CONCLUSIONS

Measurements of ABR from portable CR images can be used to estimate PCWP.