Advanced imaging assessment of posterior circulation stroke before and after endovascular intervention.

BACKGROUND: Perfusion-computed tomography (CTP) is a relatively new technique that allows rapid semiquantitative noninvasive evaluation of cerebral perfusion aiding in the diagnosis of cerebral ischemia and infarction. There is a paucity of data on its application within the posterior circulation, especially, the brainstem. We describe a case of basilar artery thrombosis with cerebellar and brainstem CTP mismatch and discuss possible future applications of CTP for acute posterior fossa circulation and infarction. METHODS: Case report. RESULTS: Successful use of CTP to aid in decision to proceed with neurointervention in acute basilar artery occlusion and confirm its resolution after mechanical clot retrieval. CONCLUSION: Perfusion-computed tomography can successfully be used to define cerebral ischemia and infarction within the posterior fossa and aid in decisions to proceed with neurointervention.

Neurologic Complications of Preoperative Embolization of Spinal Metastasis: A Systemic Review of the Literature Identifying Distinct Mechanisms of Injury.

BACKGROUND: Preoperative embolization of spinal metastases may improve outcomes of resection by reducing surgical blood loss and operative time. Neurologic complications are rarely reported and the mechanisms leading to injury are poorly described. METHODS: We present 2 illustrative cases of embolization-related neurologic injury from distinct mechanisms and the findings of a systemic literature review of similar complications according to the PRISMA guidelines. RESULTS: A 77-year-old man with a history of renal cell carcinoma presented with gait dyscoordination and arm pain/weakness. Magnetic resonance imaging showed a C7/T1 mass causing severe compression of the C7/T1 roots and spinal cord. After embolization and tumor resection/fusion, lethargy prompted imaging showing multiple posterior circulation infarcts believed to be secondary to reflux of embolic particles. A 75-year-old man with renal cell carcinoma presented with L1 level metastasis causing conus compression and experienced paraplegia after superselective particle embolization presumed to be secondary to flow disruption of the artery of Adamkiewicz. Analysis of the literature yielded 6 articles reporting instances of cranial infarction/ischemia occurring in 10 patients, 12 articles reporting spinal cord ischemia/infarction occurring in 17 patients, and 5 articles reporting symptomatic postembolization tumoral swelling in 5 patients. CONCLUSIONS: Neurologic injury is a risk of preoperative embolization of spinal metastasis from either compromise of spinal cord vascular supply or cranial stroke from reflux of embolic particles. Postprocedural tumor swelling rarely leads to clinical deficit. Awareness of these complications and the presumed mechanisms of injury may aid clinicians in implementing interventions and in counseling patients before treatment.

Radial Artery Access for Treatment of Posterior Circulation Aneurysms Using the Pipeline Embolization Device: Case Series.

BACKGROUND: The treatment of selected wide-neck and fusiform posterior circulation aneurysms is challenging for clipping as well as for endovascular route. OBJECTIVE: To describe an endovascular approach for vertebral artery aneurysm treatment using transradial access (TRA) instead of the conventional transfemoral access. METHODS: We collected cases from two institutions in which TRA was used for posterior circulation Pipeline Embolization Device (Medtronic, Dublin, Ireland) deployment. RESULTS: A total of four patients were treated. TRA was useful in the setting of extreme vessel tortuosity. We utilized 5F Terumo Glidesheath (Terumo Medical, Somerset, New Jersey), intermediate catheter, and a 027 microcatheter for Pipeline deployment. TRA was not associated with any access or deployment difficulties. CONCLUSIONS: Early experience suggests that TRA for Pipeline Embolization Device placement for posterior circulation aneurysm is a safe and efficient alternative to standard transfemoral access. While this approach was initially applied to patients with vascular anatomy that may not allow for safe femoral access or navigation, experience so far argues for considering a radial approach towards some posterior circulation aneurysm treatment.

Intraoperative Angiography for Arteriovenous Malformation Resection in the Prone and Lateral Positions, Using Upper Extremity Arterial Access.

BACKGROUND: Intraoperative angiography is routinely utilized for aneurysms and arteriovenous malformations (AVMs) to verify complete occlusion and resection. Surgery for spinal and posterior fossa neurovascular lesions is usually performed in prone position. Intraoperative angiography in the prone position is challenging and there is no standardized protocol for this procedure. OBJECTIVE: To describe our experience with intraoperative angiography in the prone and lateral positions, using upper extremity arterial access. METHODS: We reviewed our experience with intraoperative angiography in the prone position between 2014 and 2015, where vascular access was obtained via the upper extremity arteries. Patients were treated in a hybrid endovascular operating room. High cervical and intracranial lesions were studied via brachial or radial access. All accesses were obtained using ultrasonographic guidance and a small caliber arterial sheath (4F). RESULTS: Five patients were treated in the prone and lateral positions using brachial/radial artery access. Patients harbored cerebellar AVM, lateral medullary AVM, cervical arteriovenous fistula (AVF), tentorial dural AVF, and tentorial-incisural dural AVF. Patients were positioned prone (n = 2), semiprone (n = 2), and lateral (n = 1) for the surgery. Three patients were treated via right brachial artery access. Two patients were treated via radial arteries access. All patients tolerated the procedures without technical or clinical complications. Intraoperative angiography verified complete occlusion and resection in all cases prior to surgical closure. CONCLUSIONS: Intraoperative angiography in the prone and lateral positions using upper extremity access is an important adjunct. Brachial or radial access can be obtained safely and provides comfortable and quick approaches.

Wireless mobile technology to improve workflow and feasibility of MR-guided percutaneous interventions.

PURPOSE: A wireless interactive display and control device combined with a platform-independent web-based user interface (UI) was developed to improve the workflow for interventional magnetic resonance imaging (iMRI). METHODS: The iMRI-UI enables image acquisition of up to three independent slices using various pulse sequences with different contrast weighting. Pulse sequence, scan geometry and related parameters can be changed on the fly via the iMRI-UI using a tablet computer for improved lesion detection and interventional device targeting. The iMRI-UI was validated for core biopsies with a liver phantom ([Formula: see text] [Formula: see text] 40) and Thiel soft-embalmed human cadavers ([Formula: see text] [Formula: see text] 24) in a clinical 1.5T MRI scanner. RESULTS: The iMRI-UI components and setup were tested and found conditionally MRI-safe to use according to current ASTM standards. Despite minor temporary touch screen interference at a close distance to the bore ([Formula: see text]20 cm), no other issues regarding quality or imaging artefacts were observed. The 3D root-mean-square distance error was [Formula: see text] (phantom)/[Formula: see text] mm (cadaver), and overall procedure times ranged between 12 and 22 (phantom)/20 and 55 min (cadaver). CONCLUSION: The wireless iMRI-UI control setup enabled fast and accurate interventional biopsy needle placements along complex trajectories and improved the workflow for percutaneous interventions under MRI guidance in a preclinical trial.

Thrombus formation during intracranial aneurysm coil placement: treatment with intra-arterial abciximab.

BACKGROUND AND PURPOSE: The management of thrombus formation during coil placement in an intracranial aneurysm is important in minimizing periprocedural morbidity and mortality. We report on seven cases in which the primary treatment for thrombus formation during such coil placement was intra-arterial abciximab infusion. METHODS: Clinical and radiologic records of 100 consecutive patients who underwent coil placement in intracranial aneurysms at our institution during a 1-year period were reviewed. We identified seven cases (four ruptured aneurysms, three unruptured aneurysms) in which thrombus formation occurred during the procedure. RESULTS: Intra-arterial abciximab infusion, up to 5 mg, completely dissolved the thrombus in four of seven patients and almost completely dissolved it in two. In one patient with distal emboli, recanalization was not achieved. In two patients, an intravenous bolus of abciximab without 12-hour infusion was also given adjunctively. In one patient, leakage of contrast material occurred; this was related to the intra-arterial infusion. Clinically, no new neurologic deficits were directly related to the intra-arterial abciximab infusion. Six patients had good clinical outcome, and one patient died. CONCLUSION: Relatively low-dose, intra-arterial abciximab infusion can immediately dissolve an acute thrombus that forms during intracranial aneurysm coil placement. Although neither the optimal dose of intra-arterial abciximab nor the need to supplement the intra-arterial infusion with intravenous administration was established, we preliminarily found that low-dose intra-arterial abciximab infusion may be relatively effective and safe in this setting, even in patients with acute subarachnoid hemorrhage.

Transarterial balloon assisted Onyx embolization of pericallosal arteriovenous malformations.

SUMMARY: Preliminary experience using a balloon assisted technique (BAT) for embolization of arteriovenous malformations (AVM) is reported. Two patients with large pericallosal AVMs were successfully embolized with Onyx under Scepter C balloon catheter flow arrest. CLINICAL PRESENTATION: One patient presented with a large intraventricular hemorrhage and hydrocephalus. The second patient presented with a long history of seizures and a small intracerebral hemorrhage. Both patients demonstrated extensive interhemispheric AVMs with multiple arterial feeders, predominantly from the pericallosal arteries. INTERVENTION: A Marathon microcatheter was navigated into the target arterial feeders and a Scepter C occlusion balloon catheter was inflated immediately proximal. Under flow arrest, Onyx was injected via the microcatheter with excellent nidal penetration. In both cases, there was complete angiographic obliteration of the treated component of the AVM. CONCLUSIONS: Onyx embolization under balloon catheter flow arrest allows for greater nidal penetration of embolic material and improved reflux control. The technique is limited by the current deliverability of balloon catheters and the potential risk for earlier embolization of dangerous anastomosis.

Carotid cavernous fistulae occurring after the use of the Fogarty catheter in carotid surgery: a review.

The Fogarty catheter represents a major advancement for the effective removal of distal thrombi during vascular surgery, including carotid endarterectomy (CEA). One complication related to its use is injury to the cavernous carotid artery with development of a carotid cavernous fistula (CCF). Including a recent case at our institution, 21 patients with a Fogarty-related CCF have been reported since 1967. We performed a detailed review of all Fogarty-related CCFs during the treatment of carotid occlusive disease. We suggest a management algorithm for post-CEA acute carotid occlusion.

Endovascular embolization of prominent intercavernous sinuses for successful transsphenoidal resection of Cushing microadenoma: case report.

BACKGROUND AND IMPORTANCE: Prominent intercavernous sinuses may result in vigorous bleeding during transsphenoidal resection of pituitary microadenomas and lead to incomplete or aborted tumor resection. We report the use of coil embolization of the intercavernous sinuses to prevent uncontrollable bleeding before transsphenoidal surgery is reattempted. CLINICAL PRESENTATION: A 40-year-old man with Cushing disease underwent an attempt for transsphenoidal resection of an adrenocorticotrophic hormone--producing pituitary microadenoma. This approach was aborted secondary to profuse intercavernous sinus bleeding. The patient underwent endovascular coil embolization of the anterior intercavernous sinuses with complete obliteration. Six weeks later, he underwent successful transsphenoidal resection of the microadenoma. CONCLUSION: To the best of our knowledge, this is the first report of successful coil embolization of the intercavernous sinuses to prevent uncontrolled bleeding before transsphenoidal resection of pituitary microadenomas.

Aortic response to balloon injury in obese Zucker rats.

The small diameter of the carotid artery is not compatible with the evaluation of clinically available endovascular devices in the carotid balloon-injury (BI) model. We developed an endovascular BI model in the rat descending aorta, whose size is compatible with available endovascular instruments. We also tested the hypothesis that neointima formation is enhanced in the aorta of obese Zucker rats (OZR) compared with lean Zucker rats (LZR). Left external carotid arteriotomies and BI of the thoracic and abdominal aorta were performed by using a balloon catheter. Aortograms and aortic pathology were examined at 2, 4, and 10 wk after BI. At 10 wk after BI, the abdominal aorta in OZR had narrowed 8.3% ± 1.1% relative to baseline compared with an expansion of 2.4% ± 2.2% in LZR. Simultaneously, the thoracic aorta had expanded 9.5% ± 4.3% in LZR compared with stenosis of 2.8% ± 1.6% in OZR. Calculation of the intimal:medial thickness ratio revealed significantly increased neointimal formation in the OZR descending aorta compared with that in LNR. In conclusion, this minimally invasive BI model involving the rat descending aorta is compatible with available endovascular instruments. The descending aorta of OZR demonstrates enhanced neointimal formation and constrictive vascular remodeling after BI.

Balloon-assisted coiling of the proximal lobule of a paraophthalmic aneurysm causing panhypopituitarism: Technical case report.

BACKGROUND: We describe an intra-aneurysmal balloon-assisted technique to limit the coil volume in a large bilobulated paraophthalmic aneurysm. Our intent was to reduce the mass effect and presenting symptoms of diabetes insipidus (DI) with hypopituitarism. CASE DESCRIPTION: A 32-year-old woman presented with symptoms of DI and her work-up demonstrated hypopituitarism and partial bitemporal visual field defects. Cerebral angiography revealed a large paraophthalmic aneurysm with two distinctive lobules, projecting toward the pituitary fossa. The patient declined craniotomy but consented for endovascular treatment. The plan was to limit the embolization to the proximal lobule only. Initially, we used a dual microcatheter technique with a microcatheter in each lobule. A framing coil in the distal lobule did not prevent coil migration from the proximal lobule. Instead, we elected to use a Hyperform balloon in the distal lobule and were able to successfully coil the proximal lobule only. Her 3-year follow-up angiogram revealed a completely occluded aneurysm. The patient experienced resolution of the DI and improvement of her visual fields. However, she remained in hypopituitarism. CONCLUSION: Intra-aneurysmal balloon-assisted coiling of proximal aneurysmal lobules might be an alternative for the reduction of mass effect related to the coil mass. Careful follow-up is needed because subtotal occlusion carries a future risk of growth, recanalization and rupture. Unruptured intracranial carotid aneurysms can present with reversible DI and usually permanent pituitary disturbances.

Hypertrophic olivary degeneration after resection of a pontine cavernous malformation: a case report.

We report the case of a 35 year old African American female who developed hypertrophic olivary degeneration secondary to resection of a pontine cavernous malformation. The patient initially complained of headaches and diplopia. Unenhanced computed tomography (CT) and magnetic resonance images (MRI) of the brain revealed a left pontine cavernous malformation with scattered foci of recent and remote hemorrhage. The patient subsequently underwent surgical resection of the lesion. Follow up MRI 7 months post surgery demonstrated hypertrophy and T2 signal hyperintensity in the ipsilateral inferior olivary nucleus secondary to hypertrophic olivary degeneration. Familiarity with this diagnosis and its imaging characteristics is required of the radiologist to prevent erroneous diagnoses of other pathology.

Percutaneous placement of an external drain of the cisterna magna using interventional magnetic resonance imaging in a patient with a persistent cerebrospinal fluid fistula: technical case report.

OBJECTIVE: Cerebrospinal fluid diversion from the cisterna magna has been described previously but has largely been abandoned because of high complication rates and anatomic constraints. Situations still remain in which this may be the best or only alternative. We describe the use of interventional magnetic resonance imaging (iMRI) for the application of this largely forgotten procedure. PRESENTATION: A 28-year-old woman with a previously diagnosed malignant peripheral nerve sheath tumor of the thoracic spine presented with a refractory postoperative cerebrospinal fluid leak complicated by diffuse meningeal carcinomatosis. External lumbar drainage was unsuccessful because of complete tumor obliteration. An attempt at primary closure augmented with muscle flaps was also ineffective. Ventricular drainage was deferred because of concern for tumor seeding, thus necessitating a more aggressive approach. TECHNIQUE: The patient was intubated and placed in the open iMRI portal in a lateral decubitus position. Under direct image guidance, a closed-tip lumbar catheter was inserted into the cisterna magna through an iMRI-compatible biopsy needle and then connected for external drainage. CONCLUSION: To our knowledge, this is the first described use of iMRI technology for catheterization of the cisterna magna for cerebrospinal fluid diversion. Moreover, iMRI technology should be considered in future applications of complex posterior fossa shunting procedures.