'Railroad switch' technique for stent-assisted coil embolization of a wide-neck bifurcation intracranial aneurysm: technical note.

Preservation of the posterior cerebral arteries during endovascular treatment of wide-neck basilar bifurcation aneurysms remains a technical challenge despite recent device innovations. We present a novel stent deployment technique, the 'railroad switch', to protect both posterior cerebral arteries during treatment of a recurrent basilar bifurcation aneurysm. Following asymmetric basilar-posterior cerebral artery stent deployment, favoring distal placement in a posterior cerebral artery, advancement of a jailed microcatheter will advance the proximal stent into the aneurysm, protecting both posterior cerebral arteries and the native basilar terminus. This novel maneuver offers interventionalists another application of commonly used intracranial stents for endovascular management of complex basilar bifurcation aneurysms.

Flow Diverters for Treatment of 160 Ophthalmic Segment Aneurysms: Evaluation of Safety and Efficacy in a Multicenter Cohort.

BACKGROUND: Treatment of ophthalmic segment aneurysms (OSA) remains challenging. Flow diverter stents (FDS) have evolved as a promising endovascular treatment option for aneurysms of the internal carotid artery and are associated with high occlusion rates and a favorable morbidity and mortality profile. OBJECTIVE: To determine safety and efficacy of FDS for OSA in a large, multicenter cohort. METHODS: A retrospective analysis of prospectively maintained databases of 127 consecutive patients harboring 160 OSA treated with FDS was performed. Aneurysms were classified based on location and morphology. Follow-up with digital subtraction angiography (DSA) was performed 6 to 18 months after treatment. RESULTS: Follow-up DSA was available for 101 (63.1%) aneurysms with a mean follow-up of 18 months. Complete occlusion was observed in 90 aneurysms (89.1%), near-complete occlusion (>95%) in 3 (3%), and incomplete occlusion (<95%) in 8 aneurysms (7.9%). One aneurysm was retreated with another FDS (0.9%). No risk factors for incomplete occlusion were identified. The OA was occluded at the latest follow-up in 6 cases (7.1%). Permanent morbidity occurred in 4 patients (3.1%), and there was no mortality related to the FDS procedure. CONCLUSION: Treatment of OSA with FDS was found to be safe and effective. The retreatment rate was extremely low and aneurysms that occluded did not reanalyze.

Dual diagnostic catheter technique in the endovascular management of anterior communicating artery complex aneurysms.

BACKGROUND: The configuration of the anterior communicating artery (AcomA) complex is important in the endovascular treatment of AcomA complex aneurysms. In cases of codominant anterior cerebral arteries (ACA), coil embolization may result in inadvertent occlusion of the contralateral ACA due to poor visualization. A second diagnostic catheter in the contralateral carotid artery may help with visualization of this angiographic blind spot. To our knowledge, the safety and efficacy of this dual diagnostic catheter technique have never been assessed. METHODS: A cohort of consecutive patients that underwent coil embolization of an AcomA complex aneurysm at a major academic institution in the United States between 2007 and 2014 were retrospectively reviewed. RESULTS: Eighty-two patients who had an AcomA complex aneurysm treated with coil embolization were identified. The dual diagnostic catheter technique was used in 17 (20.7%) patients. Aneurysms treated with the dual diagnostic catheter technique were less frequently ruptured and had less favorable dome-to-neck ratios as well as neck width for primary coil embolization. The rate of codominant ACAs was significantly higher and stent-assisted coil embolization was performed more frequently. The rate of thromboembolic complications, angiographic outcome, and retreatment did not differ between both the groups. CONCLUSIONS: The dual diagnostic catheter technique is a safe and effective method during coil embolization of AcomA complex aneurysms and preferred for aneurysms with codominant ACAs, incorporation of either A1 or A2 segments into the aneurysm, and aneurysms with a wide neck and low dome-to-neck ratios.

Preoperative Embolization of Extra-axial Hypervascular Tumors with Onyx.

OBJECTIVE: Preoperative endovascular embolization of intracranial tumors is performed to mitigate anticipated intraoperative blood loss. Although the usage of a wide array of embolic agents, particularly polyvinyl alcohol (PVA), has been described for a variety of tumors, literature detailing the efficacy, safety and complication rates for the usage of Onyx is relatively sparse. MATERIALS AND METHODS: We reviewed our single institutional experience with pre-surgical Onyx embolization of extra-axial tumors to evaluate its efficacy and safety and highlight nuances of individualized cases. RESULTS: Five patients underwent pre-surgical Onyx embolization of large or giant extra-axial tumors within 24 hours of surgical resection. Four patients harbored falcine or convexity meningiomas (grade I in 2 patients, grade II in 1 patient and grade III in one patient), and one patient had a grade II hemangiopericytoma. Embolization proceeded uneventfully in all cases and there were no complications. CONCLUSION: This series augments the expanding literature confirming the safety and efficacy of Onyx in the preoperative embolization of extra-axial tumors, underscoring its advantage of being able to attain extensive devascularization via only one supplying pedicle.

Stratification of recanalization for patients with endovascular treatment of intracranial aneurysms.

BACKGROUND: With the increasing use of endovascular techniques in the treatment of both ruptured and unruptured intracranial aneurysms, the issue of obliteration efficacy has become increasingly important. OBJECTIVE: To systematically develop a comprehensive model for predicting retreatment with various types of endovascular treatment. METHODS: We retrospectively reviewed medical records that were prospectively collected for 305 patients who received endovascular treatment for intracranial aneurysms from 2007 to 2013. Multivariable logistic regression was performed on candidate predictors identified by univariable screening analysis to detect independent predictors of retreatment. A composite risk score was constructed based on the proportional contribution of independent predictors in the multivariable model. RESULTS: Size (>10 mm), aneurysm rupture, stent assistance, and posttreatment degree of aneurysm occlusion were independently associated with retreatment, whereas intraluminal thrombosis and flow diversion demonstrated a trend toward retreatment. The Aneurysm Recanalization Stratification Scale was constructed by assigning the following weights to statistically and clinically significant predictors: aneurysm-specific factors: size (>10 mm), 2 points; rupture, 2 points; presence of thrombus, 2 points. Treatment-related factors were stent assistance, -1 point; flow diversion, -2 points; Raymond Roy occlusion class 2, 1 point; Raymond Roy occlusion class 3, 2 points. This scale demonstrated good discrimination with a C-statistic of 0.799. CONCLUSION: Surgical decision making and patient-centered informed consent require comprehensive and accessible information on treatment efficacy. We constructed the Aneurysm Recanalization Stratification Scale to enhance this decision-making process. This is the first comprehensive model that has been developed to quantitatively predict the risk of retreatment after endovascular therapy.

The glomic artery supply of carotid body tumors and implications for embolization.

Carotid body tumors (CBT) are rare neuroendocrine neoplasms that usually present in the third or fourth decades of life and are benign in more than 95% of cases. In the angiographic literature, the arterial supply to carotid body tumors is well documented but is often incomplete, with infrequent mention of the glomic artery, a common arterial feeder described in the anatomic and pathologic literature. Through a review of our neuroendovascular patient database, we identified eight patients with CBT undergoing transarterial embolization followed by resection. Mean patient age was 51.5 years (range 29-82), and all patients were female. Mean tumor size was 91.2 cc (standard deviation [SD] 61.1, median 67.7 cc). After embolization, greater than 90% flow reduction was achieved in 5/8 patients (63%); 60-80% flow reduction was achieved in the remaining patients. Mean operative blood loss was 166 cc (SD 100, median 122 cc) and mean operative time was 252 minutes (SD 134.5, median 155 minutes). Pre-embolization angiography was reviewed to identify a glomic artery, defined as a dominant artery supplying the CBT arising from the region of the carotid bifurcation. In six of eight patients (75%) a glomic artery could be identified, arising from the common carotid artery in 4/6 patients and the external carotid artery in 2/6 patients. Thus, glomic artery to supply to CBT was identified in the majority of patients in this series. Knowledge of its presence and identification as a direct supplier, frequently from the common carotid artery itself, provides an avenue for more thorough preoperative embolization of CBT.

Middle meningeal artery arising from the basilar artery.

Various anomalies for the origin of the middle meningeal artery (MMA) have been described in the literature. However, origin of the MMA from the basilar trunk is an extremely rare variant. We report on a 54-year-old female who presented with frequent headaches; magnetic resonance imaging showed a right parietal meningioma. The abnormal origin of the middle meningeal artery from the basilar artery was diagnosed by angiography performed for preoperative embolization of the tumor. We report on the case with a review of the embryologic basis, possible explanations for this aberrant origin, and its clinical implications.

Lumbar artery pseudoaneurysm after percutaneous vertebroplasty: a unique vascular complication.

Complications from percutaneous vertebroplasty (PV) and kyphoplasty are rare and are most commonly related to cement leakage. Pseudoaneurysm of the segmental arteries has not been reported as a complication of PV in the literature. In this article, the authors describe 2 patients who presented with a lumbar pseudoaneurysm after undergoing PV at other institutions. The authors also review the optimal technique to avoid such vascular complications.

C-arm fluoroscopic cone beam CT for guidance of minimally invasive spine interventions.

BACKGROUND: Isocentric C-arm fluoroscopic cone beam CT (CBCT) is a new technique for near real time 3-D volume imaging guidance of percutaneous interventional procedures. In combination with digital flat panel detectors, CBCT has high spatial resolution with isotropic voxel size, allowing for high resolution image reconstruction in any plane, including 3D rotational reconstructions. CBCT combines the advantages of conventional CT imaging guidance with the improved spatial resolution, patient positioning, and access of fluoroscopy. OBJECTIVE: The aim of this study is to demonstrate the advantages of CBCT over conventional CT and biplane fluoroscopy for imaging guidance of minimally invasive spinal and paraspinal interventional procedures. METHODS: Five patients referred to the department of interventional neuroradiology for percutaneous spinal or paraspinal interventional procedures were intraoperatively evaluated with CBCT to assist in guidance of instrumentation placement. Procedures included transoral cervical vertebral biopsy, percutaneous thoracic vertebral biopsy, vertebroplasty, pelvic paraspinal/epidural abscess drainage, and paraspinal fiducial marker placement for treatment of osteoid osteoma. RESULTS: All procedures were successfully performed with satisfactory diagnostic yield or therapeutic effect without procedure-related complications. CONCLUSION: Isocentric C-arm fluoroscopic cone beam CT (CBCT) is a new technique for 3D volume imaging guidance of interventional procedures of the spine with the capability to produce near real time high resolution image reconstructions in any plane. Compared to conventional CT and biplane fluoroscopy, CBCT offers improved anatomic visualization allowing high accuracy instrumentation placement, improving procedure results and minimizing risk of complications.

Transoral approach to CT-guided C2 interventions.

BACKGROUND: Lesions involving C2 are unique as it is challenging to approach these lesions. The transoral approach to C2 lesions has been extensively used by surgeons and increasingly used by interventional radiologists for vertebroplasty as it is safer and less demanding than other approaches like anterolateral and posterolateral (transpedicular). However, using this approach for image-guided biopsies is little described in literature with a few cases described so far being under fluoroscopic guidance. We describe a series of 5 procedures using transoral approach - 4 biopsies (and one vertebroplasty that was published earlier) on C2 lesions under CT guidance. To our knowledge, our series is the first one where the transoral biopsies were performed using Computed Tomography (CT) guidance. OBJECTIVE: To describe our initial experience with the transoral approach to image-guided biopsies on C2 vertebra and its relative advantages and disadvantages. METHODS: We performed 5 procedures - 4 biopsies (and one vertebroplasty published earlier) on different types of lesions involving C2, through the transoral approach, using CT guidance under general anesthesia and appropriate precautions to reduce potential complications like infection, hemorrhage, etc. RESULTS: The procedures were well tolerated by the patients without any complications, immediately as well as at follow-up. All the biopsies in our series were technically successful without any minor or major complications. The biopsy yield was 50% which may be due to the thinner needles used. CONCLUSION: CT-guided transoral approach to biopsies on C2 lesions is a direct, safe, and precise technique when performed with appropriate precautions.

Fibrin sheath removal from central venous catheters: an internal snare manoeuvre.

BACKGROUND: Dysfunction of haemodialysis catheters is most commonly due to a narrowing of the catheter lumen and/or formation of a fibrin sheath around the catheter tip. Reported methods for restoring patency of the catheter lumen include passage of a J-tipped guide wire, passage of a biopsy brush through the catheter, or infusion of a thrombolytic agent into the catheter. While these methods are often effective, they suffer from several limitations. We present a minimally invasive technique to remove thrombi and debris from within the lumen of a partially thrombosed haemodialysis catheter while simultaneously stripping the fibrous sheath. METHODS: A 0.089 cm nitinol wire is bent to create a loop, which is then inserted via the catheters. Upon exiting the lumen of the catheters, the nitinol wire forces a snare open, which disrupts the fibrin sheath and catches intraluminal thrombi and debris. The technique requires no anaesthesia or recovery time. RESULTS: Initial clinical success in our series was achieved in all patients (7/7) as evidenced by restoration of target flow rates on subsequent haemodialysis. None of the patients experienced any complications as a result of the procedure. The catheter 2-, 4-, and 6-week primary success rates were 100% (8/8), 100% (8/8), and 100% (8/8) respectively with a mean duration of 17.1 weeks (range 8-40 weeks). CONCLUSIONS: The internal snare technique is an effective, inexpensive and minimally invasive approach to restoring patency to failed central venous access catheters.

New approach to the management of acute disc herniation.

BACKGROUND: Over 500,000 percutaneous disc decompression procedures have been performed in the past 20 years. Various percutaneous techniques include chemonucleolysis, percutaneous lumbar discectomy, and laser discectomy which have reported success rates in the 70% to 75% range. This retrospective evaluation of 49 patients who underwent nucleoplasty procedures for treatment of herniated discs, evaluates the effectiveness of nucleoplasty in the reduction of pain, improvement of functional activity, and reduction of pain medication. OBJECTIVE: To illustrate the effectiveness of nucleoplasty in reducing low back pain in symptomatic patients with contained herniated discs. STUDY DESIGN: A retrospective, non-randomized study. METHODS: Forty-nine patients with either axial or radicular low back pain who had undergone the nucleoplasty procedure were included in this analysis. Patients were categorized in one of three different groups depending on time elapsed since the procedure was performed: less than 6 months, between 6 months and 1 year, and greater than 1 year. Pain reduction, work impairment, leisure impairment, medication use and patient satisfaction were all recorded during this study. Pain was quantified using a numeric pain scale from 0 to 10. Work and leisure impairment were measured on a scale of 1 to 5, with 1 signifying no impairment and 5 signifying extreme impairment. Medication use and patient satisfaction were also measured on a scale of 1 to 5. RESULTS: Significant pain relief, functional improvement, and a decrease in medication use were achieved following nucleoplasty. There were no complications associated with the procedure. CONCLUSION: Nucleoplasty should be used in those patients who fail conservative medical management including medication, physical therapy, behavioral management, psychotherapy, and who are unwilling to undergo a more invasive technique such as spinal surgery.

CT guided direct transoral approach to C2 for percutaneous vertebroplasty.

BACKGROUND: Percutaneous vertebroplasty is a well-established procedure consisting of the percutaneous injection of a biomaterial, usually Polymethyl methacrylate (PMMA), into a vertebral body. In most cases, this procedure affords significant pain relief and strengthens the bone. Vertebroplasty is most typically performed successfully with patients with acute compression fractures. OBJECTIVE: We report a case of percutaneous vertebroplasty via the transoral approach, performed with computed axial tomography (CT) scan guidance. METHODS: The procedure was performed in a 74-year-old male with a C2 vertebral body lytic lesion. RESULTS: This uncomplicated, minimally invasive procedure relieved the patient's pain. The transoral route is the most direct operative approach to the pathology in the upper cervical spine. CONCLUSION: When used with the CT scanner to facilitate accurate placement of the needle, the transoral approach provides a safe and precise operative approach to the upper cervical spine.

Safety of latest-generation self-expanding stents in patients with NASCET-ineligible severe symptomatic extracranial internal carotid artery stenosis.

BACKGROUND: Patients with symptomatic extracranial internal carotid artery stenosis (> or =70%) benefit from carotid endarterectomy when compared with medical management. However, independent risk factors can significantly increase the combined stroke and death risk after carotid endarterectomy. Carotid angioplasty and stenting (CAS) is a therapeutic option in patients who are otherwise at high risk or ineligible for carotid endarterectomy. Previous-generation self-expanding stents were hampered by length foreshortening, which limited their application in multifactorial occlusive extracranial internal carotid artery stenosis. METHODS: This is a single-center, prospective, open-label, safety study of CAS with the latest-generation self-expanding stents in patients with extracranial internal carotid artery symptomatic stenosis (> or =70%). All patients included were adjudicated to be ineligible for carotid endarterectomy by a vascular surgeon and/or a neurologist according to the exclusion criteria. Primary adverse events included death and all strokes (ipsilateral and contralateral). Secondary adverse events included transient ischemic attack, myocardial infarction, stent thrombosis, need for reintervention, and presence of hematomas. All adverse events were recorded at 24 hours, 30 days, and 6 months after CAS. RESULTS: Between June 1, 2001, and January 30, 2003, 23 consecutive patients (14 women and 9 men; mean age, 65 years; age range, 48-85 years) underwent 24 extracranial CAS procedures with the latest-generation self-expanding stents. All patients had one or multiple criteria for ineligibility according to the North American Symptomatic Carotid Endarterectomy Trial. Extracranial CAS was successful in all patients, with average residual stenosis of less than 20%. One patient (4%) experienced a stroke by the 30-day periprocedure examination. The total number of primary adverse events at 6 months after CAS was 2 strokes (9%), 1 of which was contralateral to the stent placement; there were no deaths. Twenty-two patients were asymptomatic at 6 months, with a modified Rankin scale score of 1 or less. Of the 2 patients who had a stroke, 1 had a follow-up modified Rankin scale score of 3. CONCLUSION: Extracranial CAS with the latest-generation self-expanding stents is a valid alternative treatment in high-risk or North American Symptomatic Carotid Endarterectomy Trial-ineligible patients.

Pseudo-Kümmel's disease: a unique application for vertebroplasty.

Compression fractures of the vertebrae are a major public health concern. There are approximately 700,000 compression fractures of the vertebrae diagnosed on an annual basis in the thoracolumbar spine. The etiology of senile osteoporosis is multifactorial with the most significant reason being age-related bone loss. Multiple effects of compression fractures include acute and chronic pain syndromes, inability to perform activities of daily living, insomnia and depression. Conventional treatment concepts relate to immobilization of the spine, medical pain control, bracing of the back and physical therapy. Vertebroplasty was developed in the 1980s as a treatment for painful cervical hemangiomas in France. Vertebroplasty has been utilized since 1993 to treat painful, osteoporotic compression fractures. In 1891, Kümmell described the disease with a posttraumatic osteitis in which patients developed a painful kyphosis after a period of being symptom free. Inferential evidence includes that vertebrae in this disease are being subjected to a form of avascular necrosis with intraosseous vacuum phenomenon. Patients with Kümmell's disease, treated with vertebroplasty, have been reported to do very well. In a patient with an advanced case of vertebrae plana, without so intending, authors placed air into the vertebral body and created so-called pseudo-Kümmell's disease. This case report describes with high risk or extreme vertebroplasty to alleviate symptomatology. It is concluded that as the clinical experience with percutaneous vertebroplasty continues to expand, the approaches to treatment can become more focused on the specific disease state and specific treatment paradigms.