Endovascular treatment of anterior choroidal artery aneurysms

BACKGROUND AND PURPOSE: Ischemic stroke is the most common complication after surgical clipping of anterior choroidal artery (AChA) aneurysms, and the reported morbidity-mortality rates vary from 5% to 50%. We report the findings in a series of 18 consecutive patients who underwent endovascular treatment (EVT) for an AChA berry aneurysm. METHODS: In this retrospective study, the aneurysms were defined according to their size and position, the presence of a concomitant arteriovenous malformation (AVM), the mode of presentation. The patients were clinically assessed before and after the EVT, as well as at each angiographic follow-up. RESULTS: All were small-sized aneurysms, with greater diameters ranging from 2 to 8 mm (mean, 4 mm), arising from the supraclinoid internal carotid artery close to the origin of the AChA. Two were AVM-associated aneurysms. Fourteen patients (14/18 [78%]) presented with subarachnoid hemorrhage. All aneurysms were selectively embolized with coils. There was one (1/18 [5.5%]) treatment-related death due to aneurysm perforation. Another patient (1/18 [5.5%]) developed a transient controlateral hemiparesis. Fourteen patients (14/18 [78%]) were followed up clinically and angiographically for 3-32 months (mean, 14 months). None of them (re)hemorrhaged during this period. CONCLUSION: The EVT of AChA berry aneurysms is effective to protect from rebleeding. Our complication rate compares favorably with those of the surgical series.     

Influence of DCA on pulmonary (.-)V(O2) kinetics during moderate-intensity cycle exercise

PURPOSE: To test the hypothesis that pharmacological activation of the pyruvate dehydrogenase enzyme complex (PDC) with dichloroacetate (DCA) would speed phase II pulmonary oxygen uptake ((.-)V(O2)) kinetics after the onset of subsequent moderate-intensity (40-45% ((.-)V(O2)) peak) cycle exercise. METHODS: Seven healthy males (mean +/- SD age 25 +/- 4 yr, body mass 75.3 +/- 9.4 kg) performed four "square-wave" transitions from unloaded cycling to a work rate requiring 90% of the predetermined gas exchange threshold either with or without prior infusion of DCA (50 mg x kg body mass in 50 mL saline). Pulmonary ((.-)V(O2)) was measured breath-by-breath in all tests and ((.-)V(O2)) kinetics were determined from the averaged individual response to each condition using nonlinear regression techniques. RESULTS: The blood [lactate] measured immediately before the onset of exercise was significantly reduced in the DCA condition (C: 1.1 +/- 0.3 vs DCA: 0.6 +/- 0.3 mM; P < 0.01) consistent with successful activation of the PDC. However, DCA had no discernible effect on the rate at which ((.-)V(O2)) increased toward the steady state after the onset of exercise as reflected in the phase II time constant (C: 28.5 +/- 11.8 vs DCA: 29.4 +/- 14.9 s). CONCLUSIONS: The results suggest that PDC activation does not represent a principal intramuscular limitation to ((.-)V(O2)) kinetics after the onset of moderate-intensity exercise.     

Effect of ski binding parameters on knee biomechanics: a three-dimensional computational study

INTRODUCTION: Downhill skiing is a relatively safe sport, but many potentially avoidable injuries do occur. Whereas tibia and ankle injuries have been declining, severe knee sprains usually involving the anterior cruciate ligament (ACL) have increased from the 1970s to the 1990s. The goal of the present study was to evaluate the effect of the position of the binding pivot point and binding release characteristics on ACL strain during a phantom-foot fall. METHODS: We computed ACL strain using a biomechanical computer knee model to simulate the phantom-foot ACL-injury mechanism. This mechanism, which is one of the most common mechanisms of ACL injury in downhill skiing, occurs when the weight of the skier is on the inner edge of the ski during a backward fall, resulting in a sharp uncontrolled inward turn of the ski. RESULTS: The model predicts, that under simulated phantom-foot conditions, a binding with fast-release characteristics with a pivot positioned in front of the center of the boot produces less strain on the ACL. Current bindings have their pivot point approximately at the center of the heel radius. A pivot positioned at the back of the binding is more effective for sensing loads that occur at the tip of the ski. However, it is less effective for sensing loads that occur at the tail of the ski and, therefore, offers less protection during a phantom-foot fall. CONCLUSION: A binding with two pivot points, one positioned in front and the other at the back, could sense twist loads applied to the ski both at the front and at the back, and might, therefore, be a solution to reduce the occurrence of ACL injuries.     

Intratumoral injection of cyanoacrylate glue in head and neck paragangliomas

BACKGROUND AND PURPOSE: Substantial intraoperative bleeding during surgical removal of head and neck paragangliomas may be a major problem in the management of these highly vascularized tumors. Traditional preoperative embolization via a transarterial approach has proved beneficial but is often limited by complex vascular anatomy and unfavorable locations. We report our experience with the preoperative devascularization of head and neck paragangliomas by using direct puncture and an intralesional injection of cyanoacrylate. METHODS: We retrospectively analyzed nine consecutive patients with head and neck paragangliomas who were referred for preoperative devascularization. Three patients were treated for carotid-body tumors; two for vagal lesions; and four, for jugular paragangliomas. Direct puncture of the lesion was performed by using roadmap fluoroscopic guidance. Acrylic glue was injected by using continuous biplane fluoroscopy. All patients underwent postembolization control angiography and immediate postoperative CT scanning. RESULTS: Angiograms showed that complete devascularization was achieved in all cervical glomus tumors, whereas subtotal devascularization was achieved in jugular paragangliomas. In this latter location, the injection of acrylic glue was limited by the potential risk of reflux into normal brain territory via feeders from the internal carotid or vertebral artery. The tumors were surgically removed and histologically examined. No technical or clinical complications related to the embolization procedure occurred. CONCLUSION: Percutaneous puncture of paragangliomas in the head and neck region and their preoperative devascularization by intralesional injection of acrylic glue is a feasible, safe, and effective technique.     

Intra-arterial nimodipine for the treatment of symptomatic cerebral vasospasm after aneurysmal subarachnoid hemorrhage: preliminary results

BACKGROUND AND PURPOSE: Cerebral vasospasm remains a major problem in patients recovering from aneurysmal subarachnoid hemorrhage despite advances in medical, surgical, and endovascular care. Our purpose was to assess the efficacy of intra-arterial nimodipine, a calcium-channel blocker acting mainly on cerebral vessels, in preventing delayed neurologic deficits in patients with symptomatic vasospasm. METHODS: Clinical charts of 25 consecutively treated patients were retrospectively reviewed. A multifactorial decision tree was used to determine the indication for angiography and subsequent endovascular treatment. Nimodipine was infused intra-arterially via a diagnostic catheter in the internal carotid artery or vertebral artery at a rate of 0.1 mg/min. Angiographic vasospasm before endovascular treatment, immediate vessel caliber modifications, and short- and long-term clinical efficacy of the procedure were assessed. RESULTS: Thirty procedures were performed in 25 patients. Clinical improvement was observed in 19 (76%), 16 of whom improved after the first endovascular procedure, two after the second intra-arterial treatment, and one after the third. Of these 19 patients, only 12 (63%) had notable vascular dilatation at postprocedural angiography. Dilatation of infused vessels occurred in only 13 (43%) of 30 procedures. After follow-up of 3-6 months, 18 (72%) of 25 patients had a favorable outcome (Glasgow outcome scale score of 1-2 and modified Rankin scale score of 0-2). No complications were observed. CONCLUSION: Intra-arterial nimodipine is effective and safe for the treatment of symptomatic vasospasm after subarachnoid hemorrhage. Further prospective randomized studies of cerebral blood flow are needed to confirm these results.     

Carotid rupture during stent-assisted aneurysm treatment

We report the case of a supraclinoid carotid rupture during the delivery of a balloon-expandable stent in a 59-year-old patient with incidental paraclinoid berry aneurysms for whom stent-assisted coiling was planned. The deployment of the stent resulted in immediate rupture of the artery. We describe the emergent management of this complication with prolonged balloon inflation to occlude the site of rupture, a treatment that led to the discharge of the patient 2 weeks later without any sequelae.     

CT and MR imaging of nitinol stents with radiopaque distal markers

PURPOSE: To evaluate imaging characteristics and artifacts of a nitinol stent with distal tantalum markers with computed tomography (CT) angiography and magnetic resonance (MR) angiography. MATERIALS AND METHODS: A vascular phantom was built to simulate in-stent restenosis. A nitinol stent with tantalum markers (Luminexx stent) was evaluated with CT angiography in different orientations relative to the z-axis and with MR angiography in different positions relative to both B0 and the readout gradient. Stenosis measurements were compared with conventional digital subtraction angiography for both modalities. In-stent signal intensity obtained with different flip angles was assessed in two nitinol stents with distal markers (Luminexx stent and SMART stent) and one without markers (Memotherm-FLEXX stent). RESULTS: Stenosis detection was not possible with CT angiography when the stent was perpendicular to the z-axis because of streak-like artifacts induced by tantalum markers. Stenosis evaluation with multiplanar reformation was accurate when the stent was in parallel and oblique orientations relative to the table axis. With MR angiography, metallic artifacts were mostly related to the stent orientation with B0, whereas orientation of the readout gradient had little influence. The mean error (overestimation) for stenosis measurements varied between 0.1% and 7.4% for CT imaging in parallel and oblique positions and 3.6% and 9.5% for MR imaging. Higher flip angles did not improve signal intensity inside the three stents tested. CONCLUSION: CT and MR angiography can be used for evaluating the patency of stents with distal markers that are parallel or oblique relative to the table axis (iliac, carotid, or femoral stents). MR angiography is preferred if the stent is perpendicular to the table axis (renal stent).     

A genome-wide scan for childhood obesity-associated traits in French families shows significant linkage on chromosome 6q22.31-q23.2

We conducted a genome-wide search for childhood obesity-associated traits, including BMI >/==" BORDER="0">95th percentile (PCT95), 97th percentile (PCT97), and 99th percentile (PCT99) as well as age of adiposity rebound (AAR), which corresponds to the beginning of the second rise in childhood adiposity. A set of 431 microsatellite markers was genotyped in 506 subjects from 115 multiplex French Caucasian families, with at least one child with a BMI >/==" BORDER="0">95th percentile. Among these 115 pedigrees, 97 had at least two sibs with a BMI >/==" BORDER="0">95th percentile. Fine-mapping was performed in the seven most positive loci. Nonparametric multipoint analyses revealed six regions of significant or suggestive linkage on chromosomes 2q33.2-q36.3, 6q22.31-q23.2, and 17p13 for PCT95, PCT97, or PCT99 and 15q12-q15.1, 16q22.1-q24.1, and 19p13.3-p13.11 for AAR. The strongest evidence of linkage was detected on chromosome 6q22.31 for PCT97 (maximum likelihood score: 4.06) at the marker D6S287. This logarithm of odds score meets genome-wide significance tested through simulation (empirical genome-wide P = 0.01 [0.0027-0.0254]). Six independent ge-nome scans in adults have reported quantitative trait loci on 6q linked to energy or glucose homeostasis-associated phenotypes. Possible candidate genes in this region include SIM1, MCHR2, and PC-1.     

Essential Trauma Care: strengthening trauma systems round the world

Injury has become a major cause of death and disability world-wide. Systematic approaches to its prevention and treatment are needed. In terms of treatment, there are many low-cost improvements that could be made particularly in low- and middle-income countries to strengthen their trauma systems. These can be formalised under "Essential Trauma Care" programme, similar to other global programmes for major public health problems. World Health Organisation (WHO), leading the initiative in this direction, convened a meeting at Geneva in June 2002, involving Injuries and Violence Prevention Department of the WHO, the Working Group for Essential Trauma Care of the International Association for Trauma and Surgical Intensive Care (IATSIC), representatives of other organisations and trauma care clinicians representing Africa, Asia, and Latin America. The meeting developed a preliminary list of Essential Trauma Care services and a model template for the skills and equipment needed to assure them. It is intended to be used to assist individual countries in planning their own trauma care services.