Improved transoral surgical tool design by CT measurements of the oral cavity and pharynx.

The majority of head and neck cancers arise from the oral cavity and oropharynx. Many of these lesions will be amenable to surgical resection using transoral approaches including transoral robotic surgery (TORS). To develop and control TORS tools, precise dimensions of the oral cavity and pharynx are desirable. CT angiograms of 76 patients were analyzed. For the oral cavity, only the maximum length and width were measured, while for the pharynx, the width, length, and areas of the airway were all measured and the volume calculated. A prototype TORS tool was developed and tested based on the findings and dimensions. The design modification of the tool is in progress. The mean male oral cavity width and length were 93.3 ± 4.3 and 77.0 ± 7.2 mm, respectively, and the mean male pharyngeal width, length, area, and volume were 26.5 ± 7.2 mm, 16.2 ± 8.8 mm, 325 ± 149 mm2, and 28,440 ± 14,100 mm3, respectively, while the mean female oral cavity width and length were 84.5 ± 12.9 and 71.0 ± 6.3 mm, respectively, and the mean female pharyngeal width, length, area, and volume were 24.8 ± 5.6 mm, 13.7 ± 3.2 mm, 258 ± 98 mm2, and 17,660 ± 7700 mm3, respectively. The developed TORS tool was tested inside the oral cavity of an intubation mannequin. These data will also be used to develop an electronic no-go cone-shape tunnel to improve the safety of the surgical field. Reporting the oral cavity and pharyngeal dimensions is important for design of TORS tools and creating control zones for the workspace of the tool inside the oral cavity.

Combined full-dose IV and endovascular thrombolysis in acute ischaemic stroke.

BACKGROUND: There is an increasing trend to treating proximal vessel occlusions with intravenous-inter-arterial (IV-IA) thrombolysis. The best dose of IV tissue plasminogen activator (tPA) remains undetermined. We compared the combination of full-dose IV recombinant tissue plasminogen activator (rtPA) and IA thrombolytic therapy to IA therapy. METHODS: Between 2002 and 2009, we reviewed our computed tomographic angiography database for patients who received full-dose intravenous rtPA and endovascular therapy or endovascular therapy alone for acute ischaemic stroke treatment. Details of demographics, risk factors, endovascular procedure, and symptomatic intracranial haemorrhage were noted. Modified Rankin Scale ≤2 at three-months was used as good outcome. Recanalization was defined as Thrombolysis in Myocardial Ischaemia 2-3 flow on angiography. RESULTS: Among 157 patients, 104 patients received IV-IA treatment and 53 patients underwent direct IA therapy. There was a higher recanalization rate with IV-IA therapy compared with IA alone (71% vs. 60%, P < 0·21) which was driven by early recanalization after IV rtPA. Mortality and independent outcome were comparable between the two groups. Symptomatic intracranial haemorrhage occurred in 8% of patients (12% in the IA group, 7% in the IV-IA group) but was more frequent as the intensity of intervention increased from device alone to thrombolytic drug alone to device plus thrombolytic drug(s). Recanalization was a strong predictor of reduced mortality risk ratio (RR) 0·48 confidence interval95 0·27-0·84) and favourable outcome (RR 2·14 confidence interval95 1·3-3·5). CONCLUSIONS: Combined IV-IA therapy with full-dose intravenous rtPA was safe and results in good recanalization rates without excess symptomatic intracranial haemorrhage. Testing of full-dose IV tPA followed by endovascular treatment in the IMS3 trial is justified.

Impact of neuroradiologist second opinion on staging and management of head and neck cancer.

OBJECTIVE: Patients with head and neck cancer frequently present to academic tertiary referral centers with imaging studies that have been performed and interpreted elsewhere. At our institution, these outside head and neck imaging studies undergo formal second opinion reporting by a fellowship-trained academic neuroradiologist with expertise in head and neck imaging. The purpose of this study was to determine the impact of this practice on cancer staging and patient management. METHODS: Our institutional review board approved the retrospective review of randomized original and second opinion reports for 94 consecutive cases of biopsy proven or clinically suspected head and neck cancer in calendar year 2010. Discrepancy rates for staging and recommended patient management were calculated and, for the 32% (30/94) of cases that subsequently went to surgery, the accuracies of the reports were determined relative to the pathologic staging gold standard. RESULTS: Following neuroradiologist second opinion review, the cancer stage changed in 56% (53/94) of cases and the recommended management changed in 38% (36/94) of patients with head and neck cancer. When compared to the pathologic staging gold standard, the second opinion was correct 93% (28/30) of the time. CONCLUSION: In a majority of patients with head and neck cancer, neuroradiologist second opinion review of their outside imaging studies resulted in an accurate change in their cancer stage and this frequently led to a change in their management plan.

The ICV sign as a marker of increased cerebral blood transit time.

OBJECTIVE/BACKGROUND: We describe the internal cerebral vein (ICV) sign, which is a hypo-opacification of the ICV on computed tomogram angiography (CTA) as a new marker of increased cerebral blood transit-time in ipsilateral internal carotid artery occlusions (ICAO). METHODS: A retrospective analysis of 153 patients with acute unilateral M1 middle cerebral artery (MCA) occlusions ± ICAOs was performed. The degree of contrast opacification of the ICV on the ipsilesional side was compared to that of the unaffected side. RESULTS: Of 153 patients in our study, 135 had M1 MCA occlusions ± intra-cranial ICAO (M1±iICAO) and 18 had isolated extracranial ICAO (eICAO). In the patients with proximal M1±iICAO, 57/65 (87.1%) showed the ICV sign. Of the 8 patients without the ICV sign in this group, 6 had prominent lenticulostriate arteries arising from the non-occluded M1 segment, 1 had a recurrent artery of Huebner, and 1 had filling of distal ICA/M1 segment through prominent Circle of Willis collaterals. For the 70 patients with isolated distal M1±iICAO, 7/70 (10%) showed the ICV sign, with all 7 showing occluded lenticulostriate arteries. Of the patients with eICAO, 8/18 showed the ICV sign, all 8 with the ICV sign had poor Circle of Willis collaterals. CONCLUSIONS: The ICV sign correlates well with presence of proximal M1±iICAO in patients with either occluded lenticulostriate arteries or poor Circle of Willis collaterals. In patients with eICAO, the sign correlates with reduced Circle of Willis collaterals and may be a marker of increased ipsilateral cerebral blood transit time.

Initial experience with a self-expanding retrievable stent for recanalization of large vessel occlusions in acute ischemic stroke.

INTRODUCTION: Quicker recanalization results in better clinical outcomes in patients with acute ischemic strokes. We describe our experience with the use of a self-expanding, fully retrievable stent in acute intracranial occlusions. METHODS: Patients who underwent intra-arterial procedures with a self-expanding, fully retrievable stent for acute ischemic strokes at our center in 2009 were included in this study. The primary outcome was recanalization [Thrombolysis in Myocardial Infarction (TIMI) grade 2/3] at end of procedure. Secondary endpoints were procedural interval times, incidence of vasospasm, rupture of vessels, device-related complications, groin complications, postprocedural intracerebral hemorrhage (ICH) on noncontrast CT, and all-cause mortality. RESULTS: Fourteen patients (mean age 62.1 years, range 34-81 years; six males) were included in the study. Sites of occlusion are as follows: M1 middle cerebral artery (MCA, n = 8), M2 MCA (n = 1), proximal basilar artery (n = 1), and distal basilar artery (n = 4). An additional device or technique was used in 9 of 14 patients prior to the use of the retrievable stent. Twelve out of 14 (85.7%) achieved TIMI 2-3 recanalization with 4 of 14 (28.6%) achieving TIMI 3. Eight of 14 (57.1%) patients had modified Rankin Scale (0-2) at 3 months or discharge. ICH on follow-up CT was noted in 28.6% (4 of 14) of patients. All-cause mortality was 2 of 14 (14.3%). CONCLUSION: Use of a novel self-expanding, fully retrievable stent resulted in fast and very high recanalization rates in acute ischemic strokes with intravascular occlusions.

Distal anterior choroidal artery aneurysm following iatrogenic posterior cerebral artery occlusion : a case report and review of literature.

Aneurysms of the anterior choroidal artery are uncommon and account for only 2-5% of all intracranial aneurysms. Distal anterior choroidal artery aneurysms are rare and the pathogenesis of this aneurysm may be different from typical proximal ones. We describe an unusual case of ruptured de novo distal anterior choroidal artery aneurysm in a 55 year-old man who had previously undergone endovascular proximal occlusion for a fusiform aneurysm of the ipsilateral posterior cerebral artery (PCA). A comprehensive review of literature using Medline, PubMed and all related journals was also performed. Only 34 reported distal AchoA aneurysms were found: 16 associated with moyamoya disease, 10 idiopathic, two with atherosclerosis, two with arteriovenous malformation, two dissecting, one infectious and one due to trauma. It is probable that the increased hemodynamic stress within the AchoA contributed to the formation and rupture of the reported aneurysm. This late complication needs to be considered when large intracranial vessels are iatrogenically occluded in the management of complex intracranial aneurysms.

Initial experience with the Penumbra Stroke System for recanalization of large vessel occlusions in acute ischemic stroke.

INTRODUCTION: The Penumbra system is a newly approved mechanical device for the treatment of acute stroke designed for better and faster recanalization. We describe our initial experience with the use of this device. METHODS: We studied 27 consecutive patients with acute ischemic strokes due to arterial occlusions presenting at our center from January to October 2009. The primary outcome was the degree of recanalization measured by thrombolysis in myocardial infarction (TIMI grade 2/3) at the end of the procedure. Secondary end points were the proportion of patients who achieved a modified Rankin scale (mRS) ≤2 at 3 months, all-cause mortality and intracerebral hemorrhage (ICH) on non contrast computed tomography at 24 h. Procedural complications were also recorded. RESULTS: Of 27 patients (13 male, mean age 61 years) in the study, 22 (81%) patients had anterior circulation strokes and five (18%) had posterior circulation strokes. Twenty-three (85%) patients achieved TIMI grade 2/3 recanalization at completion of the procedure. Excluding five patients who needed use of a second device, the Penumbra system achieved TIMI grade 2/3 recanalization in 67% of patients. Thirteen (48%) patients had mRS ≤2 at 3-month follow-up. Procedural and post-procedural complications included vasospasm (3.7%), distal emboli (48.1%), and ICH (33.3%). The distribution of ICH is as follows: hemorrhagic infarct type 1 (25.9%), parenchymal hemorrhage type 1 (3.7%), and parenchymal hemorrhage type 2 (3.7%). All-cause mortality was 19%. CONCLUSIONS: High recanalization rates and good clinical outcomes are achievable with the Penumbra system. Complication rates are comparable to a previously published literature.

Extravasating contrast material on angiography following carotid angioplasty and stenting: not necessarily subarachnoid hemorrhage.

We describe a case of asymptomatic extravasation of iodinated contrast material into the sulci on digital subtraction angiography following carotid angioplasty and stenting resulting in sulcal hyperdensity on computed tomography (CT). We believe the mechanism for this observation is hyperperfusion injury and that in the absence of any associated clinical signs, it should not be considered alarming for subarachnoid hemorrhage.

Intracranial thrombus extent predicts clinical outcome, final infarct size and hemorrhagic transformation in ischemic stroke: the clot burden score.

BACKGROUND: In ischemic stroke, functional outcomes vary depending on site of intracranial occlusion. We tested the prognostic value of a semiquantitative computed tomography angiography-based clot burden score. METHODS: Clot burden score allots major anterior circulation arteries 10 points for presence of contrast opacification on computed tomography angiography. Two points each are subtracted for thrombus preventing contrast opacification in the proximal M1, distal M1 or supraclinoid internal carotid artery and one point each for M2 branches, A1 and infraclinoid internal carotid artery. We retrospectively studied patients with disabling neurological deficits (National Institute of Health Stroke Scale score >or=5) and computed tomography angiography within 24-hours from symptom onset. We analyzed percentages independent functional outcome (modified Rankin Scale score

Communicating hydrocephalus after endovascular coiling of unruptured aneurysms: report of 2 cases.

To the authors' knowledge, only 1 case of communicating hydrocephalus after endovascular coiling of unruptured brain aneurysms has been reported previously. Here, they report on 2 such cases of delayed communicating hydrocephalus after treatment with hydrogel-coated coils and offer the first histopathological evidence of foreign material, presumably related to the coils, as the cause of hydrocephalus.

MRI of ischemic stroke in canines: applications for monitoring intraarterial thrombolysis.

PURPOSE: To describe a canine embolic stroke model that is appropriate for endovascular procedure evaluations and develop local cerebral blood flow (CBF) maps to monitor the progression of stroke and thrombolysis. In the future, MR may displace X-ray imaging in some endovascular procedures, such as intraarterial (IA) thrombolysis for stroke therapy, due to increased monitoring capabilities. For MR to attain its full potential in endovascular therapy, the development of appropriate disease models and monitoring techniques is essential. MATERIALS AND METHODS: The canine stroke model uses an injection of autologous clot to produce ischemic and infarcted tissue and produces a range of stroke severities within the anterior cerebral circulation. Local CBF maps were formed by using the catheter that would be in place to deliver the thrombolytic agent for treatment to deliver the gadolinium-based contrast agent for perfusion imaging. RESULTS: After the injection of clot, changes on imaging were consistent with the progression of ischemic stroke. Local CBF maps showed perfusion changes with stroke progression and treatment. CONCLUSION: We successfully demonstrate the progression of ischemic stroke in the canine to mimic the progression of human stroke. CBF maps to show local perfusion characteristics show great potential in the evaluation of stroke therapy.

Assessment of brain aneurysms by using high-resolution magnetic resonance angiography after endovascular coil delivery.

OBJECT: Digital subtraction (DS) angiography is the current gold standard of assessing intracranial aneurysms after coil placement. Magnetic resonance (MR) angiography offers a noninvasive, low-risk alternative, but its accuracy in delineating coil-treated aneurysms remains uncertain. The objective of this study, therefore, is to compare a high-resolution MR angiography protocol relative to DS angiography for the evaluation of coil-treated aneurysms. METHODS: In 2003, the authors initiated a prospective protocol of following up patients with coil-treated brain aneurysms using both 1.5-tesla gadolinium-enhanced MR angiography and biplanar DS angiography. Using acquired images, the subject aneurysm was independently scored for degree of remnant identified (complete obliteration, residual neck, or residual aneurysm) and the surgeon's ability to visualize the parent vessel (excellent, fair, or poor). RESULTS: Thirty-seven patients with 42 coil-treated aneurysms were enrolled for a total of 44 paired MR angiography-DS angiography tests (median 9 days between tests). An excellent correlation was found between DS and MR angiography for assessing any residual aneurysm, but not for visualizing the parent vessel (K = 0.86 for residual aneurysm and 0.10 for parent vessel visualization). Paramagnetic artifact from the coil mass was minimal, and in some cases MR angiography identified contrast permeation into the coil mass not revealed by DS angiography. An intravascular microstent typically impeded proper visualization of the parent vessel on MR angiography. CONCLUSIONS: Magnetic resonance angiography is a noninvasive and safe means of follow-up review for patients with coil-treated brain aneurysms. Compared with DS angiography, MR angiography accurately delineates residual aneurysm necks and parent vessel patency (in the absence of a stent), and offers superior visualization of contrast filling within the coil mass. Use of MR angiography may obviate the need for routine diagnostic DS angiography in select patients.

Primary angiitis of the spinal cord presenting as a conus mass: long-term remission.

BACKGROUND: Primary angiitis of the central nervous system (CNS) is a rare vasculitic disorder that typically involves the brain and, less frequently, the spinal cord without involvement of the blood vessels outside the CNS. CASE DESCRIPTION: We present a case of a 52-year-old woman who developed a conus syndrome linked to an enhancing mass of her lower thoracic spinal cord, lumbar cord, and conus. Spinal cord biopsy performed for diagnostic purposes in the setting of progressive neurological deficit confirmed angiitis of the spinal cord. Therapy with steroid and cyclophosphamide was associated with long-term (3 years) clinical and imaging remission of the lesion. CONCLUSIONS: The prognosis of primary CNS angiitis is dismal with most cases progressing to death. Long-term remission is unusual. Aggressive therapy with steroid and cytotoxic agents may improve survival.

MR angiography compared to conventional selective angiography in acute stroke.

BACKGROUND AND PURPOSE: Accuracy of intracranial magnetic resonance angiography (MRA) and reliability of interpretation are not well established compared to conventional selective catheter angiography. The purpose of this study was to determine the accuracy of MRA in evaluation of intracranial vessels in acute stroke and transient ischemic attack (TIA) patients METHODS: Twenty-nine patients (seven females, 22 males; median age 53) with acute stroke or TIA were enrolled into the study. All patients underwent both MRA using a 3 T clinical magnet and conventional angiography within 48 hours. Median time between MRA and angiography was 263 minutes. Conventional angiography preceded MRA in 15 cases. Fourteen patients received thrombolysis during MRA or angiography. National Institutes of Health Stroke Scale scores were obtained prior to the MR exam. One neuroradiologist rated all conventional angiograms, which were used as gold standard. Five observers, blinded to conventional angiography results and all clinical information except symptom side, rated the MR angiograms. Kappa statistics were used to assess reliability; contingency tables were used to assess accuracy of non-enhanced and enhanced MRA. RESULTS: Two hundred and fifty two intracranial vessels were assessed. Agreement between raters was good for both non-enhanced (kappa = 0.50) and gadolinium-enhanced (kappa = 0.46) images. There were a total of 26 vessels occluded by DSA. Overall, the non-enhanced MRA showed sensitivity of 84.2% (95% CI 60.4-96.6) and specificity of 84.6% (95% CI 78.6-89.4). The enhanced MRA showed sensitivity of 69.2 (95% CI 38.6-90.9) and specificity of 73.6 (95% CI 65.5-80.7). CONCLUSIONS: Magnetic resonance angiography is a good non-invasive screening tool for assessing intracranial vessel status in acute ischemic stroke. Angiography remains the gold standard for definitive assessment of the intracranial circulation.

ASPECTS on CTA source images versus unenhanced CT: added value in predicting final infarct extent and clinical outcome.

BACKGROUND AND PURPOSE: The Alberta Stroke Program Early CT Score (ASPECTS) is a grading system to assess ischemic changes on CT in acute ischemic stroke. CT angiography-source images (CTA-SI) predict final infarct volume. We examined whether the final infarct ASPECTS and clinical outcome were more related to acute CTA-SI ASPECTS than to the acute noncontrast CT (NCCT) ASPECTS. METHODS: ASPECTS was assigned by 2 raters on the acute NCCT, CTA-SI, and follow-up imaging. The mean baseline ASPECTS of acute NCCT and CTA-SI was compared with the follow-up ASPECTS. Rate ratios (RRs) were used to quantify the relationship between the dichotomized baseline ASPECTS (categorized as 0 to 7 versus 8 to 10) and favorable patient outcome. RESULTS: Thirty-nine patients were recruited. Proximal occlusion (internal carotid artery or middle cerebral artery) was seen in 62%, M2 occlusion in 18%, and no occlusion was seen in 20% of patients. The median time between symptom onset and imaging was 1.9 (1.2 to 2.5) hours. There was a significantly larger difference of 1.4 between the mean baseline NCCT and CTA-SI ASPECTS in patients who had more ischemic changes (follow-up ASPECTS=0 to 3) than a difference of 0.6 in patients who had near-to-normal CT scans (follow-up ASPECTS=8 to 10). The rate of favorable outcome for acute NCCT ASPECTS of 8 to 10 was 51.8% versus 25.0% for 0 to 7 (RR, 2.1, 95% CI: 0.7 to 5.9, P=0.12). For acute CTA-SI ASPECTS of 8 to 10, the rate of favorable outcome was 58.8% versus 31.8% for 0 to 7 (RR, 1.8, 95% CI: 0.9 to 3.8, P=0.09). CONCLUSIONS: CTA-SI ASPECTS provides added information in the prediction of final infarct size.

Thunderclap headache and reversible segmental cerebral vasoconstriction associated with use of oxymetazoline nasal spray.

Oxymetazoline is a sympathomimetic amine found in over-the-counter nasal decongestants. We report a case of chronic use of nasal oxymetazoline associated with thunderclap headache due to reversible segmental intracranial vasoconstriction.

Intra-arterial thrombolysis in acute ischemic stroke: a review of pharmacologic approaches.

Ischemic stroke is a major public health problem worldwide. The potential to cure stroke patients with intravenous thrombolytic therapy has evolved to the use of intra-arterial thrombolytic agents. Fewer than 200 patients have been enrolled in randomized trials of intra-arterial therapy. In this article the authors have reviewed the literature listed in MEDLINE and EMBase, and searched relevant articles to examine the role of fibrinolytic agents in acute interventional stroke therapy. Only English language articles reporting five or more patients were included. Outcomes were defined at 90 days. Good outcome was defined on the modified Rankin Scale. Symtpomatic hemorrhage was defined as hemorrhage in the setting of clinical deterioration in the first 24 to 48 h. The search identified 57 studies of which 44 reported usable data. Only three randomized trials were reported. Of a total of 1140 patients, most (73%) were treated open-label with urokinase (Abbokinase, Abbott Laboratories). The best outcomes were reported in case series and slightly worse outcomes were reported in clinical trials. Overall, it was not possible to distinguish whether one agent was superior to the others. There is a paucity of published evidence on intra-arterial therapy for acute ischemic stroke. Alteplase (Activase, Genentech Inc.) is currently the drug of choice simply because it is available and it is the current intravenous standard. Further trials and developments are anticipated.

Mild neurological symptoms despite middle cerebral artery occlusion.

BACKGROUND AND PURPOSE: Only a small percentage of stroke patients are treated with thrombolytic therapy. We sought to determine whether vessel occlusion in mild strokes represented a new target population for interventional therapy. METHODS: We imaged 106 acute stroke patients with MRI. Patients were identified with evidence of middle cerebral artery (MCA) occlusion and mild or no stroke signs (National Institutes of Health Stroke Scale [NIHSS] 3, and MCA occlusion. RESULTS: We identified 5 patients with absent flow on MRA in the MCA and mild or no stroke signs (NIHSS

Reliability of assessing percentage of diffusion-perfusion mismatch.

BACKGROUND AND PURPOSE: Emergent neurovascular imaging holds promise in identifying new and optimum target populations for thrombolysis in stroke. Recent research has focused on patients with diffusion-weighted MRI (DWI)-perfusion-weighted MRI (PWI) mismatch as a marker of tissue at risk of infarction and a means to select the most suitable candidates for thrombolysis. The present study sought to estimate the reliability of assessing the percentage of DWI-PWI mismatch. METHODS: Thirteen patients with acute strokes had DWI and PWI within 7 hours of symptom onset. Six raters independently created relative mean transit time (rMTT) maps and then compared them with DWI images to assess the percentage of mismatch (PWI>DWI) in 10% increments. The MR scans were reassessed by 4 raters, tracing around the lesions to calculate the volume percentage of mismatch. RESULTS: Visual assessment had an interrater reliability of 0.68 (95% CI, 0.52 to 1.0; SEM=21.6%) and an intrarater reliability of 0.80 (95% CI, 0.47 to 1.0; SEM=16.9%). Hand-drawn assessment had an interrater reliability of 0.66 (95% CI, 0.45 to 1.0; SEM=26.2%) and an intrarater reliability of 0.94 (95% CI, 0.81 to 1.0; SEM=10.9%). CONCLUSIONS: Results from the present study suggest that quantifying mismatch by the human eye is reproducible but not reliable among observers. This raises doubts about using mismatch for clinical decision making and clinical trial enrollment.