Philippe Gailloud

Role of the Distal Balloon Protection Technique in the Prevention of Cerebral Embolic Events During Carotid Stent Placement

Background and Purpose — We sought to quantitatively and qualitatively evaluate the release of atheromatous plaque debris induced by carotid stenting procedures. Methods — Eight patients with severe carotid atheromatous stenoses were treated by stent implantation under distal balloon protection. Blood samplings were obtained after stent deployment in the blood pooled below the inflated protection balloon. The samples were centrifuged and evaluated for plaque debris with the use of light microscopy. The debris release was quantitatively estimated by dividing the total volume of debris obtained by the mean debris size. Five patients without endovascular procedure were used as a control group. Results — The 2 main debris types found were nonrefringent cholesterol crystals (4 to 389 &mgr;m; 115 to 8697 in number) and lipoid masses (7 to 600 &mgr;m; 341 to 34 000 in number). There was a statistically significant difference compared with the samples obtained in the control group (P =0.017). Conclusions — Blood samples collected during stent implantation procedures contain a large quantity of atheromatous plaque debris. This emphasizes the role of distal protection techniques in avoiding migration of this plaque material into the cerebral circulation.

CT angiography, MR angiography and rotational digital subtraction angiography for volumetric assessment of intracranial aneurysms. An experimental study

The purpose of our experimental study was to assess the accuracy and precision of CT angiography (CTA), MR angiography (MRA) and rotational digital subtraction angiography (DSA) for measuring the volume of an in vitro aneurysm model. A rigid model of the anterior cerebral circulation harbouring an anterior communicating aneurysm was connected to a pulsatile circuit. It was studied using unenhanced 3D time-of-flight MRA, contrast-enhanced CTA and rotational DSA angiography. The source images were then postprocessed on dedicated workstations to calculate the volume of the aneurysm. CTA was more accurate than MRA (P=0.0019). Rotational DSA was more accurate than CTA, although the difference did not reach statistical significance (P=0.1605), and significantly more accurate than MRA (P<0.00001). CTA was more precise than MRA (P=0.12), although this did not reach statistical significance. Rotational DSA can be part of the diagnosis, treatment planning and support endovascular treatment of intracranial aneurysms. The emerging endovascular treatment techniques which consist of using liquid polymers as implants to exclude aneurysms from arterial circulation would certainly benefit from this precise measurement of the volume of aneurysms.

Direct transoral approach to C2 for percutaneous vertebroplasty

nPercutaneous vertebroplasty was performed via antransoral route in a 70-year-old woman with a C2 metastasis of thyroidnorigin involving anterior vertebral elements. Complete pain relief wasnobtained after an uncomplicated minimally invasive procedure. Thisnpreliminary experience demonstrates that a transoral approach undernfluoroscopic control can provide safe access to the upper cervicalnspine at C2 level.nn

Second-generation three-dimensional reconstruction for rotational three-dimensional angiography.

RATIONALE AND OBJECTIVESnThe purpose of this study was to assess the feasibility and accuracy of three-dimensional (3D) reconstruction techniques for digital subtraction angiography (DSA) in planning and evaluation of minimally invasive image-controlled therapy.nnnMATERIALS AND METHODSnUsing a standard, commercially available system, the authors acquired DSA images and corrected them for inherent distortions. They designed and implemented parallel and multiresolution versions of cone-beam reconstruction techniques to reconstruct high-resolution targeted volumes in a short period of time. Testing was performed on anatomically correct, calibrated in vitro models of a cerebral aneurysm. These models were used with a pulsatile circulation circuit to allow for blood flow simulation during DSA, computed tomographic (CT) angiography, and magnetic resonance (MR) angiography image acquisitions.nnnRESULTSnThe multiresolution DSA-based reconstruction protocol and its implementation allowed the authors to achieve reconstruction times and levels of accuracy for the volume measurement of the aneurysmal cavities that were considered compatible with actual clinical practice. Comparison with data obtained from other imaging modalities shows that, besides vascular tree depiction, the DSA-based true 3D technique provides volume estimates at least as good as those obtained from CT and MR angiography.nnnCONCLUSIONnThe authors demonstrated the feasibility and potential of true 3D reconstruction for angiographic imaging with DSA. On the basis of the model testing, this work addresses both the timing and quantification required to support minimally invasive image-controlled therapy.

Anatomy teaching for medical undergraduates: General practice as a guideline? The brain

Basic science teaching, particularly the teaching of gross anatomy, is at present a highly controversial topic. How much and what kind of anatomy should be taught to medical undergraduates nowadays? In conducting the present study we based our proposals on the criterion of general medical relevance. Therefore, we sent an anatomical questionnaire to a sample of Swiss general practitioners. Here, we present the results derived from questions on the human brain, discussing them in connection with the other organs so far investigated. The results obtained suggest that a common body of anatomical knowledge appropriate for the field of general medical practice does in fact exist. We believe that this basic stock can serve as a guideline for decision makers involved in the development of curricula, which can be fitted into the time frame available for anatomy teaching today while still guaranteeing a sound level of competence required for general practice of medicine. We also hope that this approach may serve as a model for the teaching of other basic sciences. Clin. Anat. 12:115–119, 1999.

Visual sequelae after consensus-based treatment of ophthalmic artery segment aneurysms: the Johns Hopkins experience.

Background To determine the anatomic and visual outcomes of patients with ophthalmic artery segment aneurysms treated at The Johns Hopkins Hospital using a consensus-based treatment algorithm. Methods Retrospective record review of a prospectively accrued case series of 88 patients (101 aneurysms) treated between January 2004 and July 2009. Presenting symptoms and aneurysm parameters were recorded for all subjects. Treatment strategy for all patients was determined by consensus among neurosurgeons, neurointerventionalists, neurologists, and neuroophthalmologists meeting to review the clinical cases on a weekly basis. Final clinical outcomes (aneurysm control, functional status, and vision) were ascertained from in-house examinations, medical records, telephone interviews, or a combination of these methods. Risk factors for visual or other complications were evaluated. Results An optic neuropathy was present in at least 30 (34%) of 88 patients after treatment. Presumed new visual loss occurred in 24 (27%) of these patients. The remaining 6 patients had preexisting optic neuropathy–related visual loss that worsened after treatment. No patient with a preexisting optic neuropathy improved following treatment. Conclusion Ophthalmic artery segment aneurysms present a treatment challenge because of their anatomic complexity and relationship to critical neural structures, particularly the visual sensory pathway. We have adopted a consensus-based treatment approach in an effort to optimize patient outcomes and aneurysm control. Although our approach resulted in durable treatment of the aneurysm, a sizable proportion of patients experienced new vision loss after treatment, and no patient with preexisting visual loss related to their aneurysm experienced visual improvement after treatment. We recommend that all patients with ophthalmic artery aneurysms receive careful and thorough preprocedural counseling to ensure they are aware of the risks and benefits of treatment regardless of the method used.

Percutaneous vertebroplasty in benign and malignant disease

Percutaneous vertebroplasty is a minimally invasive procedure that offers a remarkable therapeutic option for patients with osteoporotic or tumor-related vertebral fractures and pain. It has the advantage of effecting pain relief and restoring bone biomechanical strength.

Three-dimensional reconstruction of a levator claviculae muscle

SummaryDuring routine radiological examination of a 72 year-old woman a soft-tissue shadow in the left posterior triangle of the neck was observed. Three-dimensional reconstruction of this structure suggested that it might be a muscular variant: a levator claviculae muscle. In our case it took origin from the upper part of the cervical column and was inserted into the lateral third of the clavicle. With this example as a background, the general significance of anatomical muscular variants for modern imaging techniques is discussed.RésuméLors dun examen radiologique de routine (TDM, IRM) pratiqué chez une femme de 72 ans, une image tissulaire molle fut mise en évidence dans le triangle cervical postérieur gauche. La reconstruction tridimensionnelle de cette structure a suggéré quil pouvait sagir dune variante musculaire, en loccurrence dun muscle élévateur de la clavicule. Dans notre cas, lorigine musculaire était située au niveau de la colonne cervicale supérieure et son insertion distale sur le tiers latéral de la clavicule. Cette exemple nous amène à rappeler laspect général des variantes anatomiques musculaires dans le contexte des techniques dimagerie moderne.

Relationship between intrahepatic vessels and computer-generated hepatic scissurae: an in vitro assay.

SummaryLiver segmentation is a matter of increasing importance for radiologists, in particular with respect to accurate preoperative localisation of focal hepatic lesions. Procedures for delineating the segmental anatomy from CT or MR images are therefore much in demand. In this context, a convenient technique for generating the intersegmental scissurae by computer has recently been proposed [9]. The procedure, however, seemed questionable from an anatomical point of view. We therefore checked its relevance using anatomical vascular casts of post mortem livers and comparing the computergenerated scissurae with the actual course of the intrahepatic vessels. The results presented in this paper confirm that a rigid application of flat scissural planes is not able to render the real intrahepatic compartmentation. Only techniques considering the effective individual vascular anatomy can provide a correct determination of the hepatic segments.RésuméL’anatomie segmentaire du foie est un sujet d’intérêt croissant pour les radiologistes, en particulier en raison du besoin d’une localisation préopératoire précise de pathologies hépatiques focales. Des procédés simples et efficaces pour déterminer cette anatomie segmentaire à partir d’images TDM ou IRM sont donc très recherchés. C’est dans ce contexte qu’une méthode élégante a été proposée récemment, consistant à générer par ordinateur les scissures intersegmentaires [9]. Le procédé nous semblait toutefois contestable d’un point de vue anatomique. Nous avons testé notre hypothèse sur des préparations de corrosion vasculaire en comparant les scissures générées par ordinateur au cheminement effectif des vaisseaux intrahépatiques. Les résultats obtenus confirment que toute application de plans scissuraux rigides ne peut réellement rendre compte de la compartimentation intrahépatique. Seules des techniques prenant en considération l’anatomie vasculaire individuelle authentique et dans sa totalité permettent une détermination correcte de la segmentation hépatique.

Thrombosis and subsequent recanalization of a ruptured intracranial aneurysm in 2 children, demonstrating the value of repeating catheter angiography after an initial negative study: Report of 2 cases

The cases of 2 children with true aneurysmal subarachnoid hemorrhages (SAHs) and initial false-negative angiograms are reported. In both cases, the initial angiogram was of adequate technical quality and included the projections on which aneurysms were later documented. There was no significant vasospasm at the time of initial angiography; therefore, transient aneurysm sac thrombosis was the most likely explanation for the initial false-negative studies. It is particularly interesting to note that 1 of the 2 patients had a pattern of hemorrhage compatible with the most limited definition of a perimesencephalic SAH, that is, a small prepontine cistern hemorrhage. If a second angiogram had been deemed unnecessary based on that criterion alone, a ruptured basilar tip aneurysm would have escaped detection and treatment.