Vagal Nerve Palsy After Transarterial Embolization of Transverse-Sigmoid Dural Arteriovenous Fistula Using Onyx

OBJECTIVE

We report a case of a 70-year-old man who developed a transverse-sigmoid dural arteriovenous fistula (TS-DAVF) that was successfully treated by transarterial embolization (TAE) with Onyx.

CASE PRESENTATION

The patient presented with sudden and progressive disturbance of consciousness and left hemiparesis. Magnetic resonance imaging (MRI) revealed venous infarction and hemorrhagic changes with brain swelling in the right parietal lobe. Angiography revealed a right TS-DAVF and multiple occlusions with retrograde leptomeningeal venous drainage into the cortical veins. The TS-DAVF was graded as Borden type III and Cognard type IIa+b. Because of its progressive clinical nature and wide distribution of DAVF in the occluded sinus wall, he underwent emergent TAE with liquid embolic materials including n-butyl cyanoacrylate and Onyx under informed consent by his family. Complete obliteration of the TS-DAVF was achieved, leading to a marked amelioration of symptoms, and MRI after treatment confirmed a decrease in the brain swelling. However, he suffered transient dysphagia due to right vagal nerve palsy caused by occlusion of vasa nervorum of ascending pharyngeal artery. He returned home 5 months later with a modified Rankin Scale of 1.

CONCLUSIONS

TAE with Onyx appears to be effective for aggressive TS-DAVF with a widely distributed shunt. However, the blood supply to the cranial nerves and potentially dangerous anastomoses between the external-internal carotid artery and vertebral artery should be taken into account to avoid serious complications.

In Vitro Biocompatibility of Si Alloyed Multi-Principal Element Carbide Coatings

In the current study, we have examined the possibility to improve the biocompatibility of the (TiZrNbTaHf)C through replacement of either Ti or Ta by Si. The coatings were deposited on Si and 316L stainless steel substrates by magnetron sputtering in an Ar+CH₄ mixed atmosphere and were examined for elemental composition, chemical bonds, surface topography, surface electrical charge and biocompatible characteristics. The net surface charge was evaluated at nano and macroscopic scale by measuring the electrical potential and work function, respectively. The biocompatible tests comprised determination of cell viability and cell attachment to the coated surface. The deposited coatings had C/(metal+Si) ratios close to unity, while a mixture of metallic carbide, free-carbon and oxidized species formed on the film surface. The coatings’ surfaces were smooth and no influence of surface roughness on electrical charge or biocompatibility was found. The biocompatible characteristics correlated well with the electrical potential/work function, suggesting a significant role of surface charge in improving biocompatibility, particularly cell attachment to coating's surface. Replacement of either Ti or Ta by Si in the (TiZrNbTaHf)C coating led to an enhanced surface electrical charge, as well as to superior biocompatible properties, with best results for the (TiZrNbSiHf)C coating.

Onyx extrusion through the scalp after embolization of dural arteriovenous fistula

A man in his sixties referred with symptoms of episodic left lip numbness and left arm weakness was diagnosed with a Borden type 3 dural arteriovenous fistula (DAVF) on DSA. Successful Onyx embolization of the DAVF was performed via the distal left occipital artery using an ev3 Apollo detachable tip microcatheter. He underwent surgical obliteration for the residual DAVF 3 days later. Three months later during a routine postoperative clinic visit, the patient produced a plastic bag containing multiple small pieces of Onyx cast and the detached tip of the Apollo microcatheter that had extruded out from his scalp through small spontaneous holes about 5 weeks after the embolization procedure. This spontaneous extrusion of Onyx can be alarming to the patient not expecting it; however, prior knowledge and discussion can lessen the anxiety of both the treating physician and the patient dealing with such a situation.

Delamination of tantalum porous coating from a TKA due to regional dissemination of debris

Metallic debris from metal-on-metal bearings is a recognized mode of failure that may lead to implant loosening and periprosthetic soft tissue reactions. The sequelae of metallosis have been most commonly reported with respect to total hip arthroplasty. The authors report a rare case of metallosis following a hybrid metal-on-polyethylene total knee arthroplasty that used a porous tantalum tibial knee component. A total knee arthroplasty patient who presented with knee pain but normal radiographs was found to have delamination of her tibial component that resulted in marked periprosthetic soft tissue metallosis.

Preclinical assessment of a zwitterionic tantalum oxide nanoparticle X-ray contrast agent

Tantalum oxide nanoparticles show great potential as the next generation of X-ray contrast media. Recently, we reported advances in tantalum oxide nanoparticles and identified improvements that were required for such particles to progress further. Namely, the viscosity of concentrated particles, the amount of retention in reticuloendothelial (RES) tissues, and the effect of large quantities of particles on the kidneys after administration were all identified as critical factors which needed further study, understanding, and development. Here, we report on a zwitterionic siloxane polymer nanoparticle coating that reduced the viscosity of concentrated solutions of particles by a factor of 5, decreased tissue retention of injected particles by a factor of 10, and, importantly, did not induce pathological responses in the kidneys.

[Characteristics of psychologic features of tantalum production workers]

The article covers results of psychologic examination of apparently healthy workers of contemporary tantalum production. The authors describe changes in psychoemotional state of workers engaged into major tantalum production workshops, in accordance with occupational length of service.

Hemocompatibility investigation of the NiTi alloy implanted with tantalum

A composite TiO(2)/Ta(2)O(5) nano-film has been formed on the NiTi shape memory alloy by Ta implantation. The wettability, protein adsorption, platelets adhesion and hemolysis tests are conducted to evaluate the hemocompatibility. The contact angle measurements showed that the surface of the NiTi alloy kept hydrophilic before and after Ta implantation, although the water contact angle increased with the increasing of implantation current. Both of the surface energy and the interfacial tension decreased after Ta implantation. The protein adsorption behavior was investigated by (125)I isotope labeling. The fibrinogen adsorption was enhanced by a high surface roughness or a large interfacial tension, while the albumin adsorption was insensitive to the surface modification. Platelet adhesion and activation were weakened and the hemolysis rate was reduced at least 46% after Ta implantation due to the decreased surface energy and improved corrosion resistance ability, respectively.

Fatigue performance and cyto-toxicity of low rigidity titanium alloy, Ti-29Nb-13Ta-4.6Zr

A beta type titanium alloy, Ti-29Nb-13Ta-4.6Zr, was newly designed and developed for biomedical applications. The new alloy contains non-toxic elements such as Nb, Ta, and Zr. In the present study, phases that appeared in the new alloy through various aging treatments were characterized by hardness tests and microstructural observations in order to identify the phase transformation. Fatigue properties of the new alloy were investigated. Young's modulus and cyto-toxicity of the new alloy were also evaluated. Precipitated phases distribute homogeneously over the whole specimen, and they are alpha phase, a small amount of omega phase, and beta phase when the new alloys are subjected to aging treatment at 673K for 259.2ks after solution treatment at 1063K for 3.6ks. The fatigue strength of the new alloy subjected to aging at 673K for 259.2ks after solution treatment at 1063K for 3.6ks is much better than when subjected to other aging treatments. In this case, the fatigue limit is around 700MPa. Young's modulus of the new alloy is much smaller than that of Ti-6Al-4V ELI. The cyto-toxicity of the new alloy is equivalent to that of pure Ti. Therefore, it is proposed that the new alloy, Ti-29Nb-13Ta-4.6Zr, will be of considerable use in biomedical applications.

[Surface modifications to improve biocompatibility and mechanical properties of orthopedic implants]

State of the art surface modifications on metallic materials for orthopedic and dental implants permit clinical application if implant design,manufacturing process as well as function and duration of implantation are harmonized with each other. Keeping these prerequisites in mind,hydroxylapatite is suited for closer connection of fixation elements in hard tissue. PVD or PECVD modifications can make gliding surfaces or surfaces of fixation elements abrasion resistant if the pressure-area ratio does not exceed threshold values in cases of surfaces moving relative to each other

[Effects of tantalum and its oxide on exposed workers]

OBJECTIVE

To explore effects of tantalum and its oxide on the exposed workers.

METHODS

Health examination for 113 workers exposed to tantalum and its oxide and a field survey for occupational hygiene in the workplace were carried out.

RESULTS

Workplace air concentration of tantalum and its oxide averaged 0.1 - 7.6 mg/m(3). There was no significant difference in prevalence of symptoms and signs and biochemical, pulmonary function, chest X-ray and electrocardiograph examinations between the exposed and control workers.

CONCLUSION

No adverse effect of tantalum and its oxide on the exposed workers was found.

Evaluation of hylan b gel as a soft-tissue augmentation implant material

BACKGROUND

The ideal soft tissue augmentation material should be an inert, safe, volume-filling material that is easy to use and remains in place over time. Hylan b gel, a cross-linked hyaluronic acid, may have many of these characteristics.

OBJECTIVE

We assessed the potential value of hylan b gel as a soft tissue augmentation material.

METHODS

A 12-month guinea pig model was used to investigate the tissue effects of hylan b gel versus "collagen" controls.

RESULTS

Hylan b gel was found to be biologically compatible and stable in dermal tissues. At 1 year, only hylan b gel implants were evident (12 of 16 test sites).

CONCLUSION

In this model hylan b gel performed favorably when compared with the most commonly used soft-tissue augmentation products. The material possesses many desirable implant material characteristics.

Comparison of the thrombogenicity of stainless steel and tantalum coronary stents

This study was designed to compare the thrombogenicity of stainless steel and tantalum coronary stents of the same design. Stainless steel and tantalum coronary stents are being evaluated for their utility in treating acute closure and restenosis. A major disadvantage of stainless steel stents is radiolucency. To determine whether radioopaque tantalum stents may be safely substituted for stainless steel stents, we compared the relative thrombogenicity of these materials in stents of identical design. Total platelet and fibrin deposition on the stents were determined from measurements of indium 111-labeled platelet and iodine 125-labeled fibrinogen accumulation after deployment into exteriorized chronic arteriovenous shunts in seven untreated baboons. In another series of experiments, 111In-platelet deposition was compared 2 hours after stent implantation in coronary arteries of pigs. In baboons, platelet thrombus formation on stainless steel and tantalum stents was equivalent and plateaued at approximately 2.5 x 10(9) platelets after 1 hour (p > 0.05). Fibrin deposition averaged approximately 1 mg/stent and did not differ between the stainless steel and tantalum stents (p > 0.05). In the porcine coronary model there was no significant difference in 111In-labeled platelet deposition between the stainless steel and tantalum stents (p > 0.05). This result was confirmed by scanning electron microscopic analysis of the coronary stents. Based on these two models, we conclude that there is no significant difference in the thrombogenicity of stainless steel and tantalum wire coil stents.

Tissue reaction to prosthetic materials in human temporal bones

We studied tissue reaction to polymeric silicone (Silastic), polyethylene, tantalum wire, and polytetrafluorethylene (Teflon) in temporal bones and to Silastic in removed shunt tubes. A purpose of this study was to determine which synthetic material is best for insulation of cochlear implant electrodes. We found fibrous tissue around all shunt tubes and in all bones, giant cells in some specimens, and lymphocytic infiltration in a few. We consider none of these findings to indicate bioincompatibility, except in one case with a presumed idiosyncratic reaction to Silastic. We conclude that all four materials are well tolerated by the human ear. Our finding that Silastic is well tolerated for long periods of time leads us to conclude that it is good choice for insulation for implanted wires.

Titanium, silver, and tantalum clips in brain tissue

The brain tissue reaction to a recently devised titanium haemoclip and to the conventional silver and tantalum clips were investigated in rabbit brain. Titanium, silver, and tantalum wires 5 X 0.5 X 0.5 mm in size were implanted into the white matter of the brain. After one and six months the brain specimens were sectioned, stained with haematoxylin eosin and with phosphotungstic acid Haematoxylin, and were studied by light microscopy. The examination revealed neither tissue reaction nor pigmentation in the case of titanium implant, while there was pigmentation surrounding the tantalum, and there was pigmentation as well as reactive gliosis around the silver wires.

Chronic urticaria from tantalum staples

We report herein the onset of chronic urticaria ten months after surgical implantation of tantalum staples. Intradermal testing with tantalum an urticarial response. The urticaria did not improve by treatment with antihistamines, but responded dramatically to disulfiram chelation therapy and resolved completely after surgical removal of the tantalum staples. We suspected a type 1 anaphylactic hypersensitivity to tantalum was present, but we have also considered that tantalum might have direct histamine releasing-like activity.

Tantalum oxide, silica and latex: effects on alveolar macrophage viability and lysozyme release

Tantalum an experimental bronchographic material, may be retained in the lungs for a prolonged period following bronchography. The alveolar macrophage (AM) is a cell with potential for clearing tantalum particles from the airways. We studied the in vitro effects of tantalum oxide and two other particles, silca and latex, on rabbit AM viability and lysozyme release over 30 hours. Results indicate: 1) tantalum oxide, silica, and latex particles are ingested by rabbit AM in culture; 2) tantalum oxide and silica are both toxic to AM in vitro; and 3) tantalum oxide exerts its toxic effects less rapidly on AM than does silica. On the basis of these in vitro culture results we conclude that tantalum oxide may be toxic to alveolar macrophages in vivo. Delayed lung clearance of tantalum oxide particles may be due in part to their toxic effects on alveolar macrophages.

[Causes of anastomositis after gastric resection]

The control fibrogastroscopy of the resected stomach in patients showing the clinical picture of postoperative anastomositis has proved that the application of an unresolving suture material (caprone) for a marginal suture of gastroenteroanastomosis causes post-resection inflammation of anastomosis in about 50% of cases. For improvement of surgical results the authors suggest to substitute marginal caprone sutures with catgut or tantal agraffes.

An in vitro and in vivo analysis of anodized tantalum capacitive electrodes: corrosion response, physiology, and histology

Oxidation-reduction reactions which can destroy high current-density metal-stimulating electrodes are avoided when using capacitive electrodes. The results of in vitro and in vivo testing of anodized, high surface area, sintered tantalum electrodes are presented. The corrosion response of the electrodes is excellent; there is no evidence of dissolution of the electrode. A deposit forms on the surface of the electrodes, but has little effect on the voltage response to constant current stimulation. The physiological and histopathological results indicate the capacitive tantalum electrode to be the safest yet tested.

Interference of bronchographic agents with lung surfactant

Dionosil Oily (a suspension of propyliodone crystals in peanut oil and powdered tantalum were introduced into the right principal bronchi of rabbit lungs. The left lungs were used as controls. Pressure-volume characteristics of excised lungs with Dionosil Oily or peanut oil demonstrated significantly reduced compliance on inflation at a pressure of 3-4 cm H2O. These lungs also retained less air on deflation and therefore demonstrated a significantly reduced stability index. Histological sections revealed microatelectasis closely associated with crystals and/or peanut oil. Lungs with tantalum powder were not measurably influenced by the bronchographic agents. Surface balance experiments with lung surfactant and synthetic dipalmitoyl phosphatidylcholine (DPPC) demonstrated an increased minimum surface tension due to the oil suspension of propyliodone, peanut oil and particles (propyliodone and tantalum). There is good evidence that the oil suspension of propyliodone reduced the surface activity of lung surfactant in situ. Particles also may prevent the minimum surface tension from reaching relatively low values if they enter the alveoli in sufficient quantities.

[Diffuse interstitial pulmonary fibrosis. Responsibility of hard metals]

In a factory processing Tungsten carbide and hard metals, of a hundred exposed workers, 15 showed signs of "irritation" which progressed in 5 to clinical, radiological and functional pulmonary fibrosis with altered CO transport. In one patient histological sections were studied and typical findings of dust inclusion seen. Diffuse interstitial fibrosis related to heavy metals is still not yet recognised as an industrial disease in France.

[Roentgenographic demonstration of the retrosternal lymph vessels. Animal experiments]

Roentgenographic demonstration of intraperitoneal organs and the retrosternal lymphatic system was obtained by insufflation of tantalum dust (particel size 1-5 mu) into the peritoneal cavity of 21 rats. No inflammatory reactions could be demonstrated. This contrastmedium remained over a considerably period of time in the peritoneal cavity and lymphnodes. This indicates the slow elimination of this metall.