Wilson P. Daugherty

Validation of frontal near-infrared spectroscopy as noninvasive bedside monitoring for regional cerebral blood flow in brain-injured patients

OBJECT Near-infrared spectroscopy (NIRS) offers noninvasive bedside measurement of direct regional cerebral arteriovenous (mixed) brain oxygenation. To validate the accuracy of this monitoring technique, the authors analyzed the statistical correlation of NIRS and CT perfusion with respect to regional cerebral blood flow (CBF) measurements. METHODS The authors retrospectively reviewed all cases in which NIRS measurements were obtained at a single, academic neurointensive care unit from February 2008 to June 2011 in which CT perfusion was performed at the same time as NIRS data was collected. Regions of interest were obtained 2.5 cm below the NIRS bifrontal scalp probe on CT perfusion with an average volume between 2 and 4 ml, with mean CBF values used for purposes of analysis. Linear regression analysis was performed for NIRS and CBF values. RESULTS The study included 8 patients (2 men, 6 women), 6 of whom suffered subarachnoid hemorrhage, 1 ischemic stroke, and 1 intracerebral hemorrhage and brain edema. Mean CBF measured by CT perfusion was 61 ml/100 g/min for the left side and 60 ml/100 g/min for the right side, while mean NIRS values were 75 on the right and 74 on the left. Linear regression analysis demonstrated a statistically significant probability value (p<0.0001) comparing NIRS frontal oximetry and CT perfusion-obtained CBF values. CONCLUSIONS The authors demonstrated a linear correlation for frontal NIRS cerebral oxygenation measurements compared with regional CBF on CT perfusion imaging. Thus, frontal NIRS cerebral oxygenation measurement may serve as a useful, noninvasive, bedside intensive care unit monitoring tool to assess brain oxygenation in a direct manner.

Observer Agreement Regarding the Necessity of Retreatment of Previously Coiled Recurrent Cerebral Aneurysms

Do interventional neuroradiologists agree among each other regarding retreatment of previously coiled aneurysms? Because the need for retreatment is also used as a primary outcome measure in randomized studies, this observation extends well beyond individual patients. The well-known group from the Mayo Clinic addresses that question in this article. They identified 27 previously treated intracranial aneurysms and asked 5 readers to independently rate each on a 5-point scale, and in those cases needing retreatment to indicate which type of therapy would be best. There was only fair agreement regarding retreatment and a wide variation in the type of therapy chosen for the retreatment. The study demonstrates substantial variability among observers not only in whether to retreat a recurrent aneurysm but also in how to treat it. These findings suggest that patient management varies widely across treating physicians and also calls into question the use of “retreatment” as an objective end point in clinical trials. BACKGROUND AND PURPOSE: The decision regarding whether or not to retreat a previously treated aneurysm not only directly impacts patient care but also serves as a primary outcome measure in numerous, leading randomized controlled trials of modified coils. Our aim was to determine the degree of interobserver variability regarding the need and type of treatment for recurrent aneurysms following coil embolization. MATERIALS AND METHODS: Twenty-seven previously treated recurrent aneurysms were identified. Five independent readers rated each aneurysm on a 5-point scale: 1, definitely do not retreat; 2, probably do not retreat; 3, unsure; 4, probably retreat; and 5, definitely retreat. The readers noted, in grades 2–5, the type of retreatment preferred, including simple coiling, balloon- or stent-assist coiling, or surgical clipping. Intraobserver agreement κ was calculated. Retreatment recommendations were evaluated between observers by using a Wilcoxon signed rank comparison. Descriptive statistics were performed for categoric treatment-type comparisons. RESULTS: At least 2- or 3-point differences between 2 readers were present in 17 (63%) and 11 (41%) of 27 cases, respectively. The median κ was 0.27 (range, 0.04–0.43), which indicates fair agreement. Differences between readers varied, with readers 4 and 5 more often recommending retreatment compared with reviewers 1–3 (P < .05). Wide variation was noted in treatment approach, with recommendations for surgical clipping ranging from 2 (7%) to 18 (67%) of 27 cases between readers 1 and 5. CONCLUSIONS: The current study demonstrates substantial variability among observers not only in whether to retreat a recurrent aneurysm but also how to treat it. These findings suggest that patient management varies widely across treating physicians and also calls into question the use of “retreatment” as an objective end point in clinical trials.

Medical Therapy for Ischemic Stroke: Review of Intravenous and Intra-Arterial Treatment Options

BACKGROUND Thrombolytic therapy is of proven and substantial benefit for select patients with acute cerebral ischemia. Diagnostic options and medical treatment options for acute stroke ischemia have undergone enormous changes in the past decades. Whereas initially stroke treatment was reduced to prevention, management of symptoms, and rehabilitation, nowadays a multitude of different fibrinolytic drugs are available. The wide availability of computed tomography in the late 1980s made thrombolysis a real therapeutic option because it allowed a fast and accurate differentiation between ischemic and hemorrhagic stroke. METHODS This study reviews these developments and how they have shaped our current use and understanding of thrombolytics in the treatment of acute ischemic stroke. RESULTS Patient selection remains a central aspect of thrombolytic treatment, and to date, the use of different fibrinolytics has been studied in over 20 large randomized trials for different clinical settings, time windows, and routes of administration. These studies included over 7000 patients, and led to our current understanding of the use of thrombolysis in acute stroke. CONCLUSIONS Intravenous fibrinolytic therapy within the first 3 hours of ischemic stroke onset offers substantial benefits for virtually all patients with potentially disabling deficits. In the 3- to 4.5-hour treatment window, intravenous fibrinolytic therapy has been shown to offer moderate net benefits when applied to all patients with potentially disabling deficits. Intra-arterial fibrinolytic therapy in the 3- to 6-hour window offers moderate net benefits when applied to all patients with potentially disabling deficits and large-artery cerebral thrombotic occlusions.

Safety of early ambulation after diagnostic and therapeutic neuroendovascular procedures without use of closure devices.

OBJECTIVETo evaluate the safety of manual compression and early ambulation after diagnostic and therapeutic neuroendovascular procedures. METHODSData were prospectively collected and retrospectively analyzed for consecutive patients undergoing diagnostic or therapeutic neuroendovascular procedures. Manual compression at the femoral access site was applied. The target for early ambulation was 2 hours after compression. RESULTSThree hundred forty-three patients were enrolled, of whom 295 were eligible for early ambulation. Diagnostic procedures totaled 214 (72.5%); therapeutic procedures, 81 (27.5%). Ambulation occurred at 2 hours for 82 patients who underwent a diagnostic and 11 patients who underwent a therapeutic procedure. Overall, 142 patients (66.4%) after a diagnostic and 21 patients (25.9%) after a therapeutic procedure ambulated within 3 hours; 94% of outpatients ambulated within 2 to 3 hours and were dismissed shortly thereafter. Delayed ambulation was related to nursing staff delays, recovery from general anesthesia, or patient preference. Fourteen patients (4.7%)—9 (4.2%) who had a diagnostic and 5 (6.2%) who had a therapeutic procedure—required delayed ambulation because of local oozing (8 patients), a hematoma of less than 5 cm (3 patients), a pseudoaneurysm (2 patients), or a large hematoma requiring surgical evacuation (1 patient). CONCLUSIONEarly ambulation is feasible and safe after diagnostic and therapeutic procedures and manual compression. A longer period of bed rest or the routine use of closure devices is often not required; thereby avoiding the costs associated with bed rest and the complications associated with closure devices.

Real-time myocardial perfusion contrast echocardiography and regional wall motion abnormalities after aneurysmal subarachnoid hemorrhage: Clinical article

OBJECT The pathophysiology of myocardial dysfunction after subarachnoid hemorrhage (SAH) remains unclear. Using myocardial real-time perfusion contrast echocardiography (RTP-CE), the authors evaluated microvascular function in patients with acute SAH. METHODS Over a 15-month period, 10 patients with acute SAH and evidence of cardiac dysfunction were prospectively enrolled. The authors performed RTP-CE within 48 hours of SAH diagnosis. Wall motion and myocardial perfusion were evaluated in 16 left ventricle segments. Qualitative and quantitative RTP-CE analyses were conducted to compare patients with and without regional wall motion abnormalities (RWMAs). Follow-up RTP-CE at a mean of 53.7 +/- 43 days was undertaken in patients with baseline RWMAs. RESULTS Ten patients with SAH and evidence of cardiac dysfunction were prospectively enrolled. There were 3 men and 7 women whose mean age was 63.5 +/- 10.1 years. The authors documented evidence of RWMAs in 6 patients. Normal perfusion was demonstrated by RTP-CE in all patients at baseline and follow-up, despite the presence of RWMAs. Compared with patients presenting with normal wall motion, in patients with RWMAs there was a trend for higher quantitative RTP-CE parameters, suggesting hyperemia with mean myocardial blood flow velocity (beta, s(-1)) of 1.08 +/- 0.61 (95% CI 0-2.61) compared with 1.62 +/- 0.64 (95% CI 0.94-2.29) and myocardial blood flow (A x beta, dB/s) of 0.99 +/- 0.41 (95% CI 0-2.0) versus 1.63 +/- 0.86 (95% CI 0.72-2.53). Follow-up RTP-CE was feasible in 3 patients with RWMAs. Regional systolic function was restored in those who completed follow-up. CONCLUSIONS The authors found that RTP-CE readily evaluates microvascular function in patients with SAH. Wall motion and perfusion dissociation were observed. Quantitative RTP-CE showed a trend for microvascular hyperemia in patients with RWMAs, suggesting that post-SAH myocardial dysfunction could occur in the absence of microvascular dysfunction.

Going viral: Fusiform vertebrobasilar and internal carotid aneurysms with varicella angiitis and common variable immunodeficiency - Case report

Intracranial aneurysms in the pediatric population are relatively rare entities. Immunocompromised patients (often from HIV/AIDS or pharmacological immunosuppression) represent a significant fraction of children with cerebral aneurysms. One proposed mechanism of aneurysm formation in these patients is from direct infection of the affected arteries. In this study, the authors report on a case of a 14-year-old girl with common variable immunodeficiency with T-cell dysfunction and a CSF polymerase chain reaction test positive for varicella-zoster virus who underwent evaluation for carotid and basilar artery fusiform aneurysms.

Myocardial contrast echocardiography in subarachnoid hemorrhage-induced cardiac dysfunction: case report.

OBJECTIVECardiac dysfunction is a well-known complication of aneurysmal subarachnoid hemorrhage (SAH) that is generally regarded as secondary to catecholamine excess rather than overt ischemia. Myocardial contrast echocardiography (MCE) is a novel method of evaluating cardiac function and perfusion. We report the use of MCE in a patient with SAH and correlate the results to coronary angiography. METHODSBedside MCE using Definity contrast agent (Bristol-Myers Squibb/Sanofi Pharmaceuticals, New York, NY) was performed at the onset of SAH and at the 1-week and 4-month follow-up evaluations. RESULTSA 64-year-old woman presented with aneurysmal SAH. She developed transient ST elevation on lateral electrocardiographic leads and elevated cardiac enzymes with creatine-kinase MB isoenzyme of 44.3 ng/ml and troponin of 0.62 ng/ml. An emergent coronary angiogram performed at the outside facility revealed normal coronary anatomy, ejection fraction of 30%, and midventricular akinesis. On transfer to our facility, MCE demonstrated an ejection fraction of 45% with normal coronary perfusion in the akinetic midventricular segments and normally contracting basal and apical segments. At the 4-month follow-up examination, her ejection fraction normalized to 67% and regional wall motion had improved. CONCLUSIONTo our knowledge, our case represents the first reported use of MCE in a patient with SAH. MCE demonstrating normal myocardium perfusion in the setting of normal coronary arteries on coronary angiogram and midventricular akinetic segments is compatible with nonischemic injury, which further supports the “catecholamine hypothesis” of neurogenic cardiac stunning. MCE may be a feasible noninvasive method to evaluate myocardial perfusion in the SAH population.

Rescue Retrieval of AngioGuard Embolic Capture System after Failure of Capture Sheath Retrieval in Carotid Angioplasty and Stenting

SUMMARY: This report describes the cases of 2 patients with failed retrieval of an AngioGuard distal protection device after carotid stent placement with rescue retrieval by use of a vertebral catheter. An AngioGuard was deployed before carotid angioplasty and stent placement. Attempted removal of the device with the provided recapture sheath was unsuccessful. A 5F 120-cm vertebral catheter was used to recapture and remove the AngioGuard. This technique is a simple and readily available solution for the retrieval of failed removal of a protection device.

MicroNester Coils as an Adjunct to Endovascular Embolization

OBJECTIVES/BACKGROUND In June 2003, detachable balloons were removed from the US market and were supplanted with coil embolization for parent artery sacrifice in difficult or nonsurgical aneurysms and other vascular pathologies. The current series examines the use of MicroNester pushable coils (Cook Medical, Bloomington, IN) as a low-cost and effective adjunct to detachable coils in the treatment of selected neurovascular pathologies. METHODS A retrospective analysis of all patients undergoing neurointerventional procedures from November 2003 through May 2008 was performed to identify patients in whom MicroNester coils were used as part of treatment. Analysis of coil type and number as well as pathology was performed. RESULTS MicroNesters were used in 26 cases, of which 21 were for arterial sacrifice--19 for the internal carotid artery and 2 for the vertebral artery. Fourteen were performed for intracranial aneurysms, 3 for pseudoaneurysms, 2 for carotid cavernous fistulae, 1 for a carotid blowout, and 1 for an arteriovenous malformation. Five additional procedures were transvenous, for treatment of dural arterial venous fistulae. The mean number of coils for artery sacrifice was 13, with an average of 10 MicroNesters. For transvenous embolizations, the means were 30 and 6, respectively. CONCLUSION MicroNesters are not the coil of choice for most neurointerventional procedures because they are not retrievable. However, when parent artery sacrifice or transvenous occlusion of dural arteriovenous fistulas is the goal, MicroNesters are a relatively inexpensive and equally effective alternative to more expensive, detachable coils and can reduce the procedural costs by

Angiographic reversed flow ratio as an indicator of high-grade internal carotid stenosis.

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