Neeraj Chaudhary

Treatment of carotid cavernous fistulas

Opinion statementThe treatment of a carotid cavernous fistula (CCF) depends on the severity of the clinical symptoms, its angiographic characteristics, and the risk it presents for intracranial hemorrhage. In most instances, endovascular treatment is preferred.High-flow direct CCFs usually are traumatic or are caused by rupture of a cavernous aneurysm into the sinus, but a small percentage can be spontaneous. They usually present with sudden development of a clinical triad: exophthalmos, bruit, and conjunctival chemosis. All direct CCFs should receive treatment, because they carry a high probability of intracranial hemorrhage or neurologic deterioration.Low-flow indirect or dural CCFs, either incidental or with minimal symptoms, are not associated with significant risk of intracranial hemorrhage. The accepted practice is to treat ocular symptoms conservatively with medical management or manual carotid compression. If the patient cannot tolerate the symptoms, or if signs of ocular morbidity occur, endovascular treatment is offered.The first treatment option should be endovascular embolization with a combination of detachable balloons, coils, stents, or liquid embolic agents. The procedure can be performed from either an arterial or venous approach. Use of these materials and techniques can yield a high cure rate with minimal complications.If the patient is not amenable to embolization or if the embolization fails, then surgery (surgical ligation of the internal carotid artery or packing of the cavernous sinus) should be offered.Stereotactic radiosurgery may be an elective treatment for low-flow CCFs, but it has no role in the treatment of high-flow CCFs.

Usefulness of percutaneously injected ethylene-vinyl alcohol copolymer in conjunction with standard endovascular embolization techniques for preoperative devascularization of hypervascular head and neck tumors: Technique, initial experience, and correlation with surgical observations

BACKGROUND AND PURPOSE: Few reports have described the embolization of head and neck lesions by using direct percutaneous techniques. We report our preliminary experience in the direct percutaneous embolization of hypervascular head and neck tumors by using Onyx in conjunction with standard endovascular embolization techniques. We describe the technical aspects of the procedure and its efficacy in reducing intraoperative blood loss. MATERIALS AND METHODS: We retrospectively studied 14 patients (3 females and 11 males; mean age, 33.4 years; range, 11–56 years) with 15 hypervascular tumors of the head and neck that underwent direct percutaneous embolization with Onyx in conjunction with particulate embolization. Nine paragangliomas and 6 JNAs underwent treatment. Documented blood loss was obtained from operative reports in these 15 patients with surgical resection performed 24–48 hours after the embolization. RESULTS: Intratumoral penetration with progressive blood flow stasis was achieved during each injection. A mean of 3.1 needles (20-gauge, 3.5-inch spinal needle) were placed percutaneously into the lesion (range, 1–6). The mean intraoperative blood loss was 780 mL (range, <50–2200 mL). Near total angiographic devascularization was achieved in 13 of 15 tumors. There were no local complications or neurologic deficits from the percutaneous access or embolization of these hypervascular tumors. CONCLUSIONS: In this study, the use of percutaneous injected Onyx in conjunction with standard endovascular embolization techniques in patients with hypervascular head and neck tumors seemed to enhance the ability to devascularize these tumors before operative removal.

Prasugrel is effective and safe for neurointerventional procedures

Background Clopidogrel bisulfate and aspirin are routinely administered as dual antiplatelet agents for many neurointerventional procedures, especially for intravascular stent placement. Many patients are non-responsive to clopidogrel, either secondary to drug interactions or from variations of cytochrome P450 enzymes. Prasugrel (brand name Effient, Eli Lilly and Company, Indianapolis, IN, USA) is a new antiplatelet agent that has been utilized extensively in patients undergoing cardiovascular procedures but its safety and efficacy during neurointerventional procedures have not been evaluated. Objective To examine whether prasugrel is a safe and effective alternative to clopidogrel for neurointerventional procedures, especially in those patients who are either non-responders or allergic to clopidogrel. Methods The medical records of all patients undergoing neurointerventional procedures at our institution who received prasugrel between January 2009 and July 2011 were retrospectively reviewed. A systematic chart review was performed and the following data were recorded: demographics, aneurysm location, endovascular techniques, peri- and post-procedural complications, hemorrhagic complications, clinical outcome and angiographic outcome. Results 16 patients undergoing neurointerventional procedures received prasugrel over a 2 year interval. All patients who had follow-up studies of P2Y12 inhibition had immediate therapeutic response to prasugrel. There were no complications related to ischemic or intracranial hemorrhage. Conclusion Prasugrel is a viable alternative to clopidogrel for patients undergoing neurointerventional procedures who are non-responders to clopidogrel. Further study is needed to evaluate the safety, efficacy and cost-effectiveness of prasugrel compared with clopidogrel for patients undergoing neurointerventional procedures.

High Subarachnoid Hemorrhage Patient Volume Associated with Lower Mortality and Better Outcomes

BACKGROUND High-volume centers have better outcomes than low-volume centers when managing complex conditions including subarachnoid hemorrhage (SAH). OBJECTIVE To quantify SAH volume-outcome association and determine the extent to which this association is influenced by aggressiveness of care. METHODS A serial cross-sectional retrospective study using the Nationwide Inpatient Sample for 2002 to 2010 was performed. Included were all adult (older than 18 years of age) discharged patients with a primary diagnosis of SAH admitted from the emergency department or transferred to a discharging hospital; cases of trauma or arteriovenous malformation were excluded. Survey-weighted descriptive statistics estimated temporal trends. Multilevel logistic regression estimated volume-outcome associations for inpatient mortality and discharge home. Models were adjusted for demographic characteristics, year, transfer status, insurance status, all individual Charlson comorbidities, intubation, and all patient-refined, diagnosis-related group mortality. Analyses were repeated, excluding cases in which aggressive care was not pursued. RESULTS A total of 32,336 discharges were included; 13,398 patients underwent clipping (59.1%) or coiling (40.9%). The inpatient mortality rate decreased from 32.2% in 2002 to 22.2% in 2010; discharge home increased from 28.5% to 40.8% during the same period. As SAH volume decreased from 100/year, the mortality rate increased from 18.7% to 19.8% at 80/year, 21.7% at 60/year, 24.5% at 40/year, and 28.4% at 20/year. As SAH patient volume decreased, the probability of discharge home decreased from 40.3% at 100/year to 38.7% at 60/year, and 35.3% at 20/year. Better outcomes persisted in patients receiving aggressive care and in those not receiving aggressive care. CONCLUSION Short-term SAH outcomes have improved. High-volume hospitals have more favorable outcomes than low-volume hospitals. This effect is substantial, even for hospitals conventionally classified as high volume.

Acute Life-Threatening Hemorrhage in Patients with Head and Neck Cancer Presenting with Carotid Blowout Syndrome: Follow-Up Results after Initial Hemostasis with Covered-Stent Placement

BACKGROUND AND PURPOSE: CSP in patients with HNC presenting with CBS can provide immediate hemostasis to prevent exsanguination. We evaluated the safety and efficacy of CSP to control acute life-threatening hemorrhage in patients with HNC presenting with CBS. MATERIALS AND METHODS: We retrospectively reviewed 10 patients (7 men, 3 women; mean age, 59 years) with HNC presenting with acute life-threatening hemorrhage from CBS that was treated with CSP. We studied patient demographics, presentations, procedures, initial and delayed complications, and technical and clinical outcomes on follow-up. RESULTS: All patients achieved immediate hemostasis following CSP. Periprocedural complications consisted of groin hematomas (n = 2), acute limb ischemia requiring thrombectomy, and an asymptomatic temporal lobe hemorrhage. Imaging and clinical follow-up were available for a mean of 17.7 months (range, 1–60 months). Two patients remained asymptomatic with a patent stent and no evidence of rebleeding at 17 and 21 months, respectively. Recurrent hemorrhages requiring retreatment were encountered in 3 patients secondary to stent infections (30%) at mean duration of 8 months. Neurologic morbidity resulted from stent thrombosis and stroke at 8 months in a single patient. Mortality was unrelated to CSP but was a result of palliative hospice care (n = 3) at a mean of 2 months or natural disease progression (n = 1) with documented patency of the stent at 6 months. CONCLUSIONS: Acute life-threatening hemorrhage from CBS related to advanced HNC can be safely and effectively treated with CSP. However, potential delayed ischemic or infectious complications are common in the exposed or infected neck.

Trigeminocardiac reflex during the percutaneous injection of ethylene vinyl alcohol copolymer (Onyx) into a juvenile nasopharyngeal angiofibroma: a report of two cases

The trigeminocardiac reflex (TCR) is a rare but well-described phenomenon encountered during invasive procedures involving the face, orbit, and cranial base. The reflex is characterized by the abrupt onset of hypotension, bradycardia, asystole, and dysrhythmias. With temporary cessation of the surgical procedure, vital signs typically stabilize without the need for further investigation, though anticholinergic drugs are often used to prevent prolonged hypotension and bradycardia. Two separate cases of the TCR were encountered during the percutaneous embolization of a juvenile nasopharyngeal angiofibroma with dimethylsulfoxide (DMSO) before the injection of ethylene vinyl alcohol copolymer (Onyx, ev3, Irvine, California, USA). In both cases, the injection of DMSO precipitated approximately 30 s of bradycardia/asystole, which then resolved after halting the procedure and administering anticholinergic drugs. There were no additional occurrences afterward and the patients underwent tumor excision with good recovery.

Spinal Dural Arteriovenous Fistulas: Clinical Experience with Endovascular Treatment as a Primary Therapy at 2 Academic Referral Centers

BACKGROUND AND PURPOSE: Spinal dural arteriovenous fistulas are a rare entity that, if left untreated, can lead to considerable morbidity with progressive spinal cord symptoms. The aim of this study was to evaluate the clinical outcome of patients with spinal dural arteriovenous fistulas that were primarily treated with endovascular embolization. MATERIALS AND METHODS: A retrospective review was performed of all patients from 1997–2010 who underwent treatment at 2 academic referral centers for a spinal dural arteriovenous fistula. Follow-up was performed by clinical examination, and functional status was measured by use of the Aminoff-Logue Disability Scale, McCormick classification grading, and mRS scores. The nonparametric Wilcoxon signed rank test was used to compare pretreatment and posttreatment Aminoff-Logue Disability Scale gait and micturition scores, McCormick classification grading, and mRS scores. P values < .05 were considered significant. RESULTS: A total of 38 patients were included. Five patients (2 endovascular, 3 surgical) were lost to follow-up and therefore were excluded from the analysis, 29 patients were initially treated from an endovascular approach (9 Onyx, 20 cyanoacrylate), and 4 patients were treated from a standard surgical approach. Five patients in the endovascular group subsequently underwent surgery for various reasons. The clinical improvements in the Aminoff-Logue Disability Scale gait and micturition scores, McCormick classification grading, and the mRS scores were statistically significant (P < .05, Wilcoxon signed rank test). CONCLUSIONS: We conclude that endovascular treatment of spinal dural arteriovenous fistulas can result in good clinical outcomes. Surgery remains the treatment of choice when safe embolization of the proximal radicular draining vein cannot be obtained or because the shunting artery of the spinal dural arteriovenous fistula also supplies the anterior spinal, posterior spinal, or a radiculomedullary artery.

Utilization of the Neuron 6 French 0.053 inch inner luminal diameter guide catheter for treatment of cerebral vascular pathology: continued experience with ultra distal access into the cerebral vasculature

Objective To describe our experience with very distal placement of the Neuron 6 F 0.053 inch inner luminal diameter guide catheter (Penumbra Inc, San Leandro, California, USA) within the intracranial and extracranial vasculature to allow treatment of various neurovascular pathologies. Previously, this was thought to be only possible with a microcatheter. Methods 12 cases are presented in which traditional guide catheters were unable to successfully navigate tortuous anatomy or provide stable support for intervention. Results The Neuron 6 F 0.053 inch inner luminal diameter delivery catheter (Penumbra) was placed in a very distal location within the internal carotid artery, external carotid artery and venous system enabling successful endovascular treatment of the intracranial pathology with no related neurological complications. Conclusion All lesions were successfully treated through a microcatheter advanced in a coaxial fashion through the distally placed guide catheter. There were no complications related to the distal position of the guide catheter.

Preliminary experience with the percutaneous embolization of paragangliomas at the carotid bifurcation using only ethylene vinyl alcohol copolymer (EVOH) Onyx

Background/purpose Carotid body paragangliomas are rare hypervascular lesions which may benefit from preoperative devascularization to reduce intraoperative blood loss. The optimal method for devascularization of these tumors is not known. Our purpose was to evaluate the extent of angiographic devascularization and intraoperative blood loss using only ethylene vinyl alcohol copolymer (EVOH) for percutaneous glomus tumor embolization. Methods A consecutive series of seven paragangliomas located at the carotid bifurcation were treated with percutaneous embolization with EVOH as the sole embolic agent. Results Complete devascularization of seven paragangliomas was achieved in all cases percutaneously with only EVOH. There were no complications. The average intraoperative blood loss was 55 ml (range 15–80 ml). Conclusions Our preliminary experience suggests that EVOH may offer a higher degree of devascularization when compared with other embolic agents. This may facilitate easier surgical resection with lower blood loss. EVOH seems to be safe when percutaneously injected as the sole embolic agent.

Radiation dose reduction during neurointerventional procedures by modification of default settings on biplane angiography equipment

Background Neurointerventional procedures represent a significant source of ionizing radiation. We sought to assess the effect during neurointerventional procedures of varying default rates of radiation dose in fluoroscopy (F) and image acquisition (IA) modes, and frame rates during cine acquisition (CINE) on total X-ray dose, acquisition exposures, fluoroscopy time, and complications. Methods We retrospectively reviewed procedures performed with two radiation dose and CINE settings: a factory setting dose cohort (30 patients, F 45 nGy/pulse, IA 3.6 μGy/pulse, factory CINE frame rate) and a reduced dose cohort (30 patients, F 32 nGy/pulse, IA 1.2 μGy/pulse, with a decreased CINE frame rate). Total radiation dose, dose area product, number of acquisition exposures, fluoroscopy time, and complications were compared between the groups. Means comparisons (t tests) were employed to evaluate differences in the outcome variables between the two groups. p Value <0.05 was considered significant. Results The reduced dose cohort had a significant reduction in mean radiation dose (factory, 3650 mGy; reduced, 1650 mGy; p=0.005) and dose area product (factory, 34 700 μGy×m2; reduced, 15 000 μGy×m2; p=0.02). There were no significant differences between cohorts in acquisition exposure (p=0.73), fluoroscopy time (p=0.45), or complications. Conclusions Significant reductions in radiation dose delivered by neurointerventional procedures can be achieved through simple modifications of default radiation dose in F and IA and frame rate during CINE without an increase in procedural complexity (fluoroscopy time) or rate of complications.