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Biomedical subjects

Kieran J Murphy

Publications and source records attributed to Kieran J Murphy.

At least 19 recordsLinked to original sources

Safety of cerebral digital subtraction angiography in children: complication rate analysis in 241 consecutive diagnostic angiograms.

BACKGROUND AND PURPOSE: Catheter-based cerebral angiography remains an important diagnostic tool in the pediatric population, particularly considering the currently growing interest in diagnosing and treating cerebrovascular disorders in children. There are no recent estimates of the complication rate associated with modern diagnostic digital subtraction angiography (DSA) in the pediatric population. The purpose of this study was to estimate the rate of complications occurring during cerebral angiography in children. METHODS: Data from 241 consecutive pediatric cerebral angiograms performed at a single institution were entered into an institutional review board-approved database. Information on patient demographics, DSA indication, neurovascular diagnosis, and intra procedural and postprocedural complications was collected. RESULTS: Our population included 115 boys and 90 girls, with age ranging from 1 week to 18 years (mean+/-SD, 12+/-5 years). All angiograms were technically successful. No intraprocedural complication was noted; in particular, there was no occurrence of iatrogenic vessel injury (dissection) and no transient or permanent neurological deficit secondary to a thromboembolic event. One child with a complex dural arteriovenous fistula experienced a fatal intracranial rehemorrhage secondary to a posterior fossa varix rupture 3 hours after completion of an uneventful diagnostic angiogram. The rates of intraprocedural and postprocedural complications were therefore 0.0% (95% CI, 0.0% to 1.4%) and 0.4% (95% CI, 0.012% to 2.29%), respectively. CONCLUSIONS: The rate of immediate complications occurring during diagnostic cerebral angiography in children is very low. No intraprocedural complication was documented in the reported series. DSA performed by experienced angiographers is a safe procedure that can provide critical diagnostic information.

Adolescent↗

Diagnosis and management of vein of galen aneurysmal malformations.

Vein of Galen aneurysmal malformations (VGAM) are rare intracranial vascular anomalies typically found in children. The anatomic landmark of a VGAM is the presence of multiple arteriovenous shunts draining into a dilated median prosencephalic vein, an embryonic vessel normally absent at the adult stage. This article reviews the developmental anatomy, the clinical presentation, and the current management of VGAM.

Bioethical Issues↗

Embolization for intractable epistaxis.

It is estimated that 60% of the population experiences epistaxis at least once in a lifetime, and that approximately 6% of these patients require treatment. We discuss the risks and benefits of an endovascular approach in our experience. We believe this option is often offered too late. By following basic rules the procedure is very safe and highly effective.

Adult↗

Controlled release of a nitric oxide donor for the prevention of delayed cerebral vasospasm following experimental subarachnoid hemorrhage in nonhuman primates.

OBJECT: Results of prior studies in rats and rabbits show that the alteration of vasomotor tone in vasospasm following periadventitial blood exposure may be reversed, at least in part, by the administration of compounds releasing nitric oxide (NO). The authors have now generalized this finding to nonhuman primates. METHODS: Ten cynomolgus monkeys underwent cerebral angiography before and 7 days following the induction of subarachnoid hemorrhage (SAH) by the placement of 2 to 3 ml clotted autologous blood around the supraclinoid carotid, proximal anterior cerebral, and proximal middle cerebral arteries. An ethylene vinyl acetate copolymer, either blank (five animals) or containing 20% w/w (Z)-1-[2-(2-aminoethyl)-N-(2-aminoethyl)amino]diazen-1-ium-1,2-diolate (DETA/NO, 4.3 mg/kg; five animals) was placed adjacent to the vessels at the time of surgery. Animals were killed on Day 7 post-SAH following repeated cerebral angiography. The mean percentage of control vascular areal fraction was calculated from angiograms. Cerebral vessels were sectioned and the mean percentage of lumen patency was calculated. One animal that had received the DETA/NO polymer died prior to repeated angiography. In the remaining animals, DETA/NO caused a significant decrease in vasospasm compared with controls, according to both angiographic (84.8 +/- 8.6 compared with 56.6 +/- 5.2%, respectively, p < 0.05) and histological studies (internal carotid artery 99.3 +/- 1.8 compared with 60.1 +/- 4.4%, respectively, p < 0.001; middle cerebral artery 98.4 +/- 3 compared with 56.1 +/- 3.7%, respectively, p < 0.001; and anterior cerebral artery 89.2 +/- 8.5 compared with 55.8 +/- 6.3%, respectively, p < 0.05). CONCLUSIONS: The controlled release of DETA/NO is effective in preventing delayed cerebral vasospasm in an SAH model in nonhuman primates. The death of one animal in the treatment group indicates that the present dosage is at the threshold between therapeutic efficacy and toxicity.

Animals↗

Pseudofenestration of the cervical internal carotid artery: a pathologic process that simulates an anatomic variant.

Fenestration of the cervical segment of the internal carotid artery (ICA) is considered an extremely rare anatomic variant, with, to the best of our knowledge, only four cases reported in the literature. We report six angiographic observations of apparent fenestration of the cervical ICA, which we believe are secondary to arterial dissection. We discuss the angiographic appearance of these pseudofenestrations and their potential clinical implications.

Adult↗

Three-dimensional digital angiography: new tool for simultaneous three-dimensional rendering of vascular and osseous information during rotational angiography.

Three-dimensional (3D) digital subtraction angiography (DSA) is the latest development in the neurovascular imaging armamentarium. 3D-DSA combines the anatomic resolution of DSA with 3D visualization abilities previously offered by only CT or MR angiography. 3D-DSA provides more detailed information than does DSA alone in the evaluation of neurovascular lesions, such as cerebral aneurysms. However, the inability of 3D-DSA to simultaneously image osseous and vascular structures is noted as a weakness of this technique compared with CT angiography. We describe a new 3D digital angiography reconstruction algorithm that allows the concurrent display of the cerebral vasculature and the osseous landmarks.

Adult↗

Treatment considerations for vertebroplasty in men.

BACKGROUND AND PURPOSE: Vertebroplasty is now a widely accepted image-guided intervention in patients with compression fracture. The purpose of this report is to look specifically at the male population undergoing vertebroplasty and identfy the management considerations distinct to men. METHODS: The hospital medical records and radiographic studies of 24 men treated with vertebroplasty between February 1999 and November 2000 were retrospectively reviewed. RESULTS: Five patients presented with idiopathic or secondary osteoporosis. In two of these five men, malignancies were discovered by core biopsies taken at the time of vertebroplasty. Thirteen patients (54%) had secondary osteoporosis. Of this group, 10 patients (42%) were steroid dependent and three (13%) were hypogonadal. Five patients (21%) had traumatic events leading to fracture. One presented with known metastases. CONCLUSION: Primary osteoporosis in men is unusual. In male patients without a definable cause of osteoporosis, known metastatic disease, or a significant history of trauma, the routine performance of a vertebral biopsy through the vertebroplasty needle before the injection of bone cement is indicated to identify unexpected neoplasm.

Aged↗

Segmental agenesis of the internal carotid artery distal to the posterior communicating artery leading to the definition of a new embryologic segment.

We report a case of segmental agenesis of the right internal carotid artery (ICA) in a 53-year-old woman, associated with a saccular aneurysm of the left anterior cerebral artery (A1 segment) presenting with a right hemispheric transient ischemic attack. The agenetic segment was located distal to the origin of the posterior communicating artery (PComA), as documented both angiographically and by direct surgical inspection. This observation suggests the existence of a previously unrecognized embryologic segment of the ICA, located between the PComA origin and the terminal bifurcation of the ICA into the anterior and middle cerebral arteries.

Angiography, Digital Subtraction↗

Prevention of cerebral vasospasm by a humanized anti-CD11/CD18 monoclonal antibody administered after experimental subarachnoid hemorrhage in nonhuman primates.

OBJECT: Leukocyte-endothelial cell interactions occurring in the first hours after subarachnoid hemorrhage (SAH) initiate changes in the endothelium and vessel wall that lead to an influx of leukocytes and the development of chronic vasospasm days later. Upregulation of intercellular adhesion molecule-1 (ICAM-1), also called CD54, appears to be a crucial step in this process. There is increasing experimental evidence that blocking the interaction between ICAM-1, which is expressed on endothelium, and integrins such as lymphocyte function-associated antigen-1 (CD11a/CD18) and macrophage antigen-1 (complement receptor 3, CD11b/CD18), which are expressed on the surface of leukocytes,prevents not only inflammation of vessel walls but also chronic vasospasm. The authors extend their previous work with monoclonal antibody (mAb) blockade of leukocyte migration to a nonhuman primate model of chronic, posthemorrhagic cerebral vasospasm. METHODS: Before surgery was performed, six young adult male cynomolgus monkeys underwent baseline selective biplane common carotid and vertebrobasilar artery cerebral angiography via a transfemoral route. On Day 0, a right frontosphenotemporal craniectomy was performed with arachnoid microdissection and placement of 2 to 3 ml of clotted autologous blood in the ipsilateral basal cisterns. The animals were given daily intravenous infusions of 2 mg/kg of either a humanized anti-CD11/CD18 or a placebo mAb beginning 30 to 60 minutes postoperatively. The monkeys were killed on Day 7 after a repeated selective cerebral angiogram was obtained. The area of contrast-containing vessels observed in each hemisphere on anteroposterior angiographic views was calculated for the angiograms obtained on Day 7 and expressed as a percentage of the area on baseline angiograms (percent control areal fraction). Review of flow cytometry and enzyme immunoassay data confirmed the presence of the anti-CD11/CD18 antibody in the serum and bound to leukocytes in the peripheral blood of treated animals. Comparisons of the groups revealed 53 +/- 4.8% control vascular areal fraction in the placebo group (two animals) and 95.8 +/- 9.4% in the anti-CD11/CD18-treated group (three animals), a statistically significant difference (p = 0.043, t-test). CONCLUSIONS: These results show that blockade of leukocyte migration into the subarachnoid space by an anti-CD11/CD18 mAb is effective in preventing experimental cerebral vasospasm in nonhuman primates, despite the unaltered presence of hemoglobin in the subarachnoid space. These experimental data support the hypothesis that inflammation plays a role in cerebral vasospasm after SAH.

Animals↗

De novo aneurysm formation 6 and 22 months after initial presentation in two patients.

Two cases of angiographically and surgically documented de novo intracranial aneurysm formation are reported. The first patient, a 32-year-old woman, developed two new aneurysms within a 6-month period, and the second patient, a 27-year-old woman, developed two new aneurysms within a 22-month period. In both patients, the new aneurysms were symptomatic, causing stroke and subarachnoid hemorrhage, respectively. The development of aneurysms de novo over such a short period of time has important implications for periodic imaging in patients considered to be at high risk for intracranial aneurysm formation.

Adult↗

Combined stent placement and thrombolysis in acute vertebrobasilar ischemic stroke.

BACKGROUND AND PURPOSE: Acute vertebrobasilar ischemic stroke is often associated with high morbidity and mortality with limited therapeutic options. Endovascular treatment with thrombolysis has offered some hope for affected patients; however, overall outcomes have been less than satisfactory. In this report, we present the results of our approach in six consecutive cases of acute vertebrobasilar ischemic stroke by combined proximal vessel stent placement and thrombolysis. METHODS: Six consecutive cases were retrospectively reviewed for the clinical outcome of patients presenting to our institution with acute posterior circulation stroke who underwent cerebral revascularization including proximal arterial stent placement by using balloon-expandable coronary stents and intraarterial thrombolysis. All of these patients were initially evaluated by stroke team neurologists and imaged with MR, including diffusion-weighted imaging documenting acute posterior circulation stroke. MR angiography of the circle of Willis was also obtained. Short-term follow-up was conducted to assess National Institutes of Health stroke scores (NIHSS) and modified Rankin scores. RESULTS: In these six cases, a combined approach of proximal arterial stent placement (five cases of vertebral artery origin and one case of carotid and subclavian stent placement plus vertebral artery revascularization) and thrombolysis was performed at variable times after stroke onset (range, 30 hours to 5 days). Four of the six patients had good basilar artery recanalization (Thrombolysis in Myocardial Infarction [TIMI] grade 0-1 before tissue plasminogen activator thrombolysis and TIMI grade 2 after procedure). Four of six patients had excellent immediate recovery and were discharged to an acute rehabilitation unit or their homes with improved neurologic symptoms and functional status. Two patients died: one patient presented with coma at outset with an NIHSS of 38, and the other patient probably had reocclusion of the basilar artery within 24 hours despite initial postprocedural improvement. CONCLUSION: We demonstrate that, in the setting of acute stroke, stent placement in combination with revascularization and thrombolysis is practical and allows quick access to a clot and simultaneously increases perfusion through collaterals during the thrombolytic process. In particular, basilar thrombolysis may be facilitated by proximal vertebral stent placement as concomitant atheromatous vertebrobasilar stenosis is common.

Acute Disease↗

Percutaneous pediculoplasty: polymethylmethacrylate injection into lytic vertebral pedicle lesions.

Two patients with painful lytic lesions of the vertebral pedicle were treated with percutaneous pediculoplasty. This technique, similar to vertebroplasty but with increased procedural risks because of the immediate vicinity of neural structures, was performed under high-quality biplane fluoroscopic guidance. For lesions involving both the pedicle and the vertebral body, a double-needle unipedicular technique is advocated.

Adolescent↗

Superior bronchial artery arising from the left common carotid artery: embryology and clinical considerations.

A bronchial artery arising from the left common carotid artery was incidentally documented during cerebral angiography in a 64-year-old patient. This variant can be understood as the adult persistence of a primitive bronchial branch arising from the third branchial arch. It represents a potential pitfall for the identification and treatment of the bleeding source in patients with hemoptysis.

Angiography, Digital Subtraction↗