OBJECTIVE: Preoperative endovascular embolization of intracranial tumors is performed to mitigate anticipated intraoperative blood loss. Although the usage of a wide array of embolic agents, particularly polyvinyl alcohol (PVA), has been described for a variety of tumors, literature detailing the efficacy, safety and complication rates for the usage of Onyx is relatively sparse. MATERIALS AND METHODS: We reviewed our single institutional experience with pre-surgical Onyx embolization of extra-axial tumors to evaluate its efficacy and safety and highlight nuances of individualized cases. RESULTS: Five patients underwent pre-surgical Onyx embolization of large or giant extra-axial tumors within 24 hours of surgical resection. Four patients harbored falcine or convexity meningiomas (grade I in 2 patients, grade II in 1 patient and grade III in one patient), and one patient had a grade II hemangiopericytoma. Embolization proceeded uneventfully in all cases and there were no complications. CONCLUSION: This series augments the expanding literature confirming the safety and efficacy of Onyx in the preoperative embolization of extra-axial tumors, underscoring its advantage of being able to attain extensive devascularization via only one supplying pedicle.
Hemangiopericytoma ; Humans ; Meningioma ; Polyvinyl Alcohol

Aims: This research was conducted to develop and characterize polyvinyl alcohol (PVA)/montmorillonite (MONT) clay incorporated with carvacrol (Carva) nanocomposite film as a potential material in wound dressing. Methodology and results: Organophilic MONT clay, which was initially modified from commercial MONT clay by cetyltrimethylammonium bromide (CTAB), was used in the polymerization process using PVA. The synthesized nanocomposites were visualized via transmission electron microscopy (TEM). The developed film (PVA/MONT/Carva nanocomposite film) was characterized via Fourier transform infrared (FTIR). The investigation on mechanical property and antimicrobial activity of the film was also performed. All nanocomposites are spherical, with a size of 92.8 ± 22.1 nm. The -OH stretch, C-H stretch, aromatic group, SiO stretch, and C-O from acetyl group were identified in the PVA/MONT/Carva nanocomposite films. During the chemical release test, carvacrol attained a plateau at 24 h, with a total release of 62.3%. This nanocomposite exhibited a severe detrimental influence on the growth of Gram-bacteria and yeasts, which represented a broad spectrum of antimicrobial agents. All test microorganisms showed approximately up to 82% reduction of microbial growth during the Hohenstein challenge test. Physically, the nanocomposite films were yellowish and apparent. The film was sturdy, flexible, elastic and consisted of excellent water holding capacity. Conclusion, significance and impact of study PVA/MONT/Carva nanocomposite film may have a useful potential to be merged in the pharmaceutical application, especially in wound dressing production.
Polyvinyl Alcohol ; Bentonite ; Wound Healing

Congenital renal arteriovenous malformation is a rare lesion. Nephrectomy or partial nephrectomy is a well-known treatment and as alternative method, transcatheter embolization therapy has been developed. We report a case of congenital arteriovenous malformation manifested by intermittent right flank pain and gross hematuria with blood clots, cured by means of transcatheter embolization therapy during angiographic study with polyvinyl alcohol foam (IVALON).
Arteriovenous Malformations* ; Flank Pain ; Hematuria ; Kidney ; Nephrectomy ; Polyvinyl Alcohol

The most possible complication of transnasal reconstruction of medial orbital wall fracture is infection of the dependent sinuses. As a result, endoscopic reduction in a medial blowout fracture with sinusitis and nasal polyp has been avoided. The silastic sheet and Merocel packing, which are placed in the ethmoid sinus, may cause or worsen sinusitis since they could cover up the natural ostia in the vicinity of sinuses. The spread of infection into the orbital wall and the difficulty of recognizing between herniated orbital tissues, infection and nasal polyp makes it difficult to perform endoscopic reduction when there are concomitant sinusitis and nasal polyp. The author reports three recently encountered cases of endoscopic reduction of medial blowout fracture with sinusitis and nasal polyp.
Dimethylpolysiloxanes ; Ethmoid Sinus ; Formaldehyde ; Nasal Polyps ; Orbit ; Polyvinyl Alcohol ; Sinusitis

This review introduces a brief description on the featured properties of polyvinyl alcohol based on hydrogel dressings. During past ten years many new artificial polymeric dressings have been developed, which meet requirements of wound healing. This review mainly focuses on one representative of ideal polymeric wound dressing membranes, polyvinyl alcohol based hydrogel dressings. But as the hydrogels with single component have low mechanical strength, recent trends have offered composite hydrogel membranes to achieve the ideal wound dressing requirements.
Bandages ; Hydrogels ; Polyvinyl Alcohol ; Tensile Strength ; Wound Healing

OBJECTIVETo prepare nanofibrous membranes of poly (vinyl alcohol)/chitosan (PVA/CS) loaded with varied salvianic acid A sodium (SAS) contents.

METHODSUltrafine fiber mats were prepared with PVA/CS as matrix and SAS as model drug. The structure and morphology of the nanofibrous membranes were characterized by FT-IR and SEM. Drug-loading amount and drug release profiles of these membranes were determined by UV VIS spectra, and the degradation of the membranes was also investigated.

RESULTSAverage diameters of PVA/CS/SAS nanofibers with different SAS contents were 280 ≊390 nm. Drug-loading amount of these nanofibrous membranes was high and exhibited sustained and controlled release behavior for SAS.

CONCLUSIONThe PVA/CS/SAS nanofibrous membrane prepared in this study loads drug uniformly and has remarkably sustained release behavior, which may offer strategies for the research and development of novel topical drug delivery systems.

Gelatin and hydroxyapatite were introduced to polyvinyl alcohol (PVA) hydrogel with an attempt to enhance the performances of PVA hydrogel. Through a reiterative freezing-thawing methods, three kinds of PVA composite hydrogels were prepared. The mechanical performances of these composite hydrogels with the same PVA and HA content but varying gelatin content, such as tensile strength, elasticity modulus, creep curve, relaxation curve and friction coefficient were evaluated by using a computer-controlled universal electronic mechanical testing machine and a UMT-II frictional testing machine. The additional effects of hydroxylapatite and varying gelatin on the performances of composite PVA hydro-gels were analyzed. It was found that the gelatin content directly influenced the physical performances of PVA composite hydrogels; but no linear relationship was recorded. PVA composite hydrogel containing 2wt-% gelatin gave optimal results, i.e. tensile strength of 5.5MPa, compressive elastical modulus of 1.48MPa, creeping rate of 31% in 45 minutes, stress relaxing rate of 40.3%, and the starting friction coefficient of 0.332.
Elastic Modulus ; Friction ; Hydrogels ; chemical synthesis ; chemistry ; Mechanical Phenomena ; Polyvinyl Alcohol ; chemical synthesis ; chemistry ; Tensile Strength

This study sought to explore a new compound polyvinyl alcohol-collagen as a wound dressing. To make the polymer, Polyvinyl alcohol (PVA) and collagen type I were put together in the ratio of 3:1, at the same time, polyethlene glycol as porogen was added, and the material was dried by air to be a membrane in shape. Then the ultimate tensile load, the hole diameter, porosity, and water absorption were measured. The cell biocompatibility was tested as well. The results showed the PVA-collagen blend had the average hole 100-150 microm in diameter, and the porosity about 90%. The ultimate tensile load reached 8.10 +/- 0.28 MPa, and water absorption was up to 185.42% +/- 6.93%. 3T3 cells grew well on the PVA-collagen member. Therefore, the PVA-collagen memberane is characterized not only by its ideal biomechanical ability and biocompability, but also by its ideal hole diameter, porosity and water absorption. It may have the potential for use as a wound dressing in vivo.
Biocompatible Materials ; chemical synthesis ; chemistry ; Collagen ; chemistry ; Humans ; Occlusive Dressings ; Polyvinyl Alcohol ; chemistry

This study aims to investigate the preparation process and in vitro release behavior of artesunate polylactic acid microspheres, in order to prepare an artesunate polylactic acid (PLA) administration method suitable for hepatic arterial embolization. With PLA as the material and polyvinyl alcohol (PVA) as the emulsifier, O/W emulsion/solvent evaporation method was adopted to prepare artesunate polylactic acid microspheres, and optimize the preparation process. With drug loading capacity, encapsulation efficiency and particle size as indexes, a single factor analysis was made on PLA concentration, PVA concentration, drug loading ratio and stirring velocity. Through an orthogonal experiment, the optimal processing conditions were determined as follows: PLA concentration was 9. 0% , PVA concentration was 0. 9% , drug loading ratio was 1:2 and stirring velocity was 1 000 r x min(-1). According to the verification of the optimal process, microsphere size, drug loading and entrapment rate of artesunate polylactic acid microspheres were (101.7 +/- 0.37) microm, (30.8 +/- 0.84)%, (53.6 +/- 0.62)%, respectively. The results showed that the optimal process was so reasonable and stable that it could lay foundation for further studies.
Artemisinins ; chemistry ; Calibration ; Drug Compounding ; methods ; Lactic Acid ; chemistry ; Microspheres ; Polyesters ; Polymers ; chemistry ; Polyvinyl Alcohol ; chemistry

PURPOSE: The purpose of this study was to investigate the effect of the number of measurement points on the calculation of transverse relaxation time (T2) with a focus on muscle T2. MATERIALS AND METHODS: This study assumed that muscle T2 was comprised of a single component. Two phantom types were measured, 1 each for long (“phantom”) and short T2 (“polyvinyl alcohol gel”). Right calf muscle T2 measurements were conducted in 9 healthy male volunteers using multiple-spin-echo magnetic resonance imaging. For phantoms and muscle (medial gastrocnemius), 5 regions of interests were selected. All region of interest values were expressed as the mean ± standard deviation. The T2 effective signal-ratio characteristics were used as an index to evaluate the magnetic resonance image quality for the calculation of T2 from T2-weighted images. The T2 accuracy was evaluated to determine the T2 reproducibility and the goodness-of-fit from the probability Q. RESULTS: For the phantom and polyvinyl alcohol gel, the standard deviation of the magnetic resonance image signal at each echo time was narrow and mono-exponential, which caused large variations in the muscle T2 decay curves. The T2 effective signal-ratio change varied with T2, with the greatest decreases apparent for a short T2. There were no significant differences in T2 reproducibility when > 3 measurement points were used. There were no significant differences in goodness-of-fit when > 6 measurement points were used. Although the measurement point evaluations were stable when > 3 measurement points were used, calculation of T2 using 4 measurement points had the highest accuracy according to the goodness-of-fit. Even if the number of measurement points was increased, there was little improvement in the probability Q. CONCLUSION: Four measurement points gave excellent reproducibility and goodness-of-fit when muscle T2 was considered mono-exponential.
Humans ; Magnetic Resonance Imaging ; Male ; Muscle, Skeletal ; Polyvinyl Alcohol ; Relaxation ; Volunteers