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Biomedical subjects

Philippe Gailloud

Publications and source records attributed to Philippe Gailloud.

At least 37 records · Page 2Linked to original sources
PubMed2005

Three-dimensional fusion digital subtraction angiography: new reconstruction algorithm for simultaneous three-dimensional rendering of osseous and vascular information obtained during rotational angiography.

This report describes three-dimensional (3D) fusion digital subtraction angiography (FDSA), a new algorithm for rotational angiography that combines reconstructions of the blood vessels and the osseous frame in a single 3D representation. 3D-FDSA is based on separate reconstructions of the mask and contrast sequences of the rotational acquisition. The two independent 3D data sets (3D-bone and 3D-digital subtraction angiography [DSA]) are fused in a single 3D representation. The algorithm uses a modification of the Feldkamp method that compensates for signal intensity inhomogeneity inherent to the reconstruction of nonsubtracted rotational acquisitions. By separately reconstructing the osseous and vascular information obtained from the rotational angiogram, 3D-FDSA provides optimal angiographic resolution and precise topographic analysis even when the studied vascular tree is in the immediate vicinity of bone.

Algorithms↗
PubMed2004

The chemistry of acrylic bone cements and implications for clinical use in image-guided therapy.

Advances in image-guided therapy for vertebral fractures and other bone-related disorders have made acrylic bone cement an integral part of the interventional armamentarium. Unfortunately, information on the properties and chemistry of these compounds is mostly published in the biomaterial sciences literature, a source with which the interventional community is generally unfamiliar. This review focuses on the chemistry of bone cement polymerization and the properties of components in polymethylmethacrylate (PMMA)-based polymers, the most commonly used bone cements in interventional procedures such as percutaneous vertebroplasty. The effects of altering the concentration of components such as methylmethacrylate monomers, PMMA beads, benzoyl peroxide activator, N,N-dimethyl-p-toluidine (DMPT) initiator, and radiopacifiers on the setting time, polymerization temperature, and compressive strength of the cement are also considered. This information will allow interventional radiologists to manipulate bone cement characteristics for specific applications and maximize the clinical potential of image-guided interventions.

Bone Cements↗
PubMed2004

A review of complications associated with vertebroplasty and kyphoplasty as reported to the Food and Drug Administration medical device related web site.

In 2002, approximately 38,000 vertebroplasties and 16,000 kyphoplasties were performed in the United States. As the use of both modalities for the treatment of vertebral compression fractures has increased, so have questions regarding safety and efficacy. The authors addressed this by reviewing both the current literature and complications data reported to the Food and Drug Administration (FDA) Center for Devices and Radiological Health through the on-line database (http://www.fda.gov/cdrh/maude.html) and through the Office of the Freedom of Information Act at the FDA. Although both procedures are largely safe, the FDA data highlight two main concerns: reactions to the use of acrylic (polymethylmethacrylate) bone cement, including hypotension and, in some cases, death, especially when multiple vertebral levels are treated in one setting; and a possible increased risk with kyphoplasty of pedicle fracture and cord compression.

Access to Information↗
PubMed2004

The sphenoparietal sinus of breschet: does it exist? An anatomic study.

BACKGROUND AND PURPOSE: The termination of the superficial middle cerebral vein is classically assimilated to the sphenoid portion of the sphenoparietal sinus. This notion has, however, been challenged in a sometimes confusing literature. The purpose of the present study was to evaluate the actual anatomic relationship existing between the sphenoparietal sinus and the superficial middle cerebral vein. METHODS: The cranial venous system of 15 nonfixed human specimens was evaluated by the corrosion cast technique (12 cases) and by classic anatomic dissection (three cases). Angiographic correlation was provided by use of the digital subtraction technique. RESULTS: The parietal portion of the sphenoparietal sinus was found to correspond to the parietal portion of the anterior branch of the middle meningeal veins. The sphenoid portion of the sphenoparietal sinus was found to be an independent venous sinus coursing under the lesser sphenoid wing, the sinus of the lesser sphenoid wing, which was connected medially to the cavernous sinus and laterally to the anterior middle meningeal veins. The superficial middle cerebral vein drained into a paracavernous sinus, a laterocavernous sinus, or a cavernous sinus but was never connected to the sphenoparietal sinus. All these venous structures were demonstrated angiographically. CONCLUSION: The sphenoparietal sinus corresponds to the artificial combination of two venous structures, the parietal portion of the anterior branch of the middle meningeal veins and a dural channel located under the lesser sphenoid wing, the sinus of the lesser sphenoid wing. The classic notion that the superficial middle cerebral vein drains into or is partially equivalent to the sphenoparietal sinus is erroneous. Our study showed these structures to be independent of each other; we found no instance in which the superficial middle cerebral vein was connected to the anterior branch of the middle meningeal veins or the sinus of the lesser sphenoid wing. The clinical implications of these anatomic findings are discussed in relation to dural arteriovenous fistulas in the region of the lesser sphenoid wing.

Aged↗
PubMed2004

Sinus pericranii: clinical and imaging findings in two cases of spontaneous partial thrombosis.

Sinus pericranii is an unusual venous anomaly characterized by communication of pericranial varicosities with an underlying dural sinus. We report two cases of spontaneous partial thrombosis of sinus pericranii presenting as focally tender, nonreducible mass lesions different in character from the baseline venous abnormality. CT, CT angiography, and CT venography (CTV) were performed in both cases. CTV was essential in depicting thrombi within the varicosities. MR (in one case) demonstrated the anomaly well, but the thrombus was not evident. Conservative therapy was instituted in both cases.

Adult↗
PubMed2004

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↗
PubMed2004

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↗
PubMed2004

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↗
PubMed2004

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↗
PubMed2003

Bilateral tentorial sinus drainage of the basal vein (of Rosenthal).

We report a case of bilateral collateral tentorial venous sinus drainage of the basal vein (of Rosenthal) (BV). The observation was made on a corrosion cast of the cerebral venous system obtained from a fresh cadaver. Radiographic correlation was obtained by performing standard X-ray imaging of the corrosion cast. Embryologic and clinical considerations are discussed.

Aged↗
PubMed2003

Percutaneous vertebroplasty in metastatic disease: transpedicular access and treatment of lysed pedicles--initial experience.

For the treatment of lytic disease involving the pedicles of vertebrae in patients with metastatic disease, the authors performed percutaneous vertebroplasty by using an access route via the lysed pedicle. Fifty-one pedicles were treated in 32 consecutive patients. In all cases, a radiologically satisfactory filling of both the affected pedicle and the vertebral body was achieved. Clinically effective pain relief was obtained in 24 (75%) of 32 patients, and no clinical complications were observed.

Adult↗
PubMed2003

Artificial cerebral aneurysm model for medical testing, training, and research.

Artificial models of cerebral aneurysms for medical training and testing of medical devices were constructed from corrosion casts of the main cerebral arteries of a human specimen. Three aneurysms with a variety of shapes were simulated at typical locations. Rigid and soft models were made of silicone using the "lost wax" technique. The transparent silicone models were anatomically accurate and reproducible copies of human vascular casts. These models could be connected in a closed circuit that used an electric pump to simulate pulsatile flow. Endovascular procedures and surgical clip application were performed under fluoroscopic or direct visual control. Surgical clipping, endoluminal coil manipulation, and consecutive hemodynamic changes were visualized by digital subtraction angiography and direct observation. The model provides trainee surgeons with an understanding of clinical conditions. New medical devices, such as platinum coils, would be experimentally implanted in the model under stable conditions. These anatomically accurate and reproducible models of cerebral vasculature and aneurysms are valuable for medical testing, training, and research.

Corrosion Casting↗
PubMed2003

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↗