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

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

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

Coronary artery perforation is a rare and serious complication in coronary angioplasty. Some patients complicated by coronary perforation may develop cardiac tamponade, which is generally due to massive hemorrhage in the pericardial space between the epicardium and the pericardium. We report a case of coronary artery perforation producing impending tamponade, which was successfully treated by transcatheter embolization of distal circumflex artery using polyvinyl alcohol.
Angioplasty ; Arteries* ; Cardiac Tamponade ; Coronary Vessels ; Hemorrhage ; Humans ; Pericardium ; Polyvinyl Alcohol* ; Polyvinyls*

PURPOSE: This study was designed to determine the embolic effect of PVA particles of various sizes on the cerebral artery of a cat and to determine the appropriate particle size for embolization. MATERIALS AND METHODS: A total of 21 cats were divided into three groups according to the PVA particle size injected: group I(n=7), embolized with 45-150 micrometer PVA; group II(n=7), with 150-250 micrometer PVA; and group III(n=7), with 350-500 micrometer PVA. PVA particles were slowly injected into the left common carotid artery of each cat, and T2-weighted coronal MR images were obtained 24 hours after injection. During histologic examination of brain sections we analyzed the size, number of occluded vessels, and the ischemic changes caused by the particles. RESULTS: On T2 weighted images, areas of high signal intensity (infarction) were observed in four of the seven cats (57%) in group Iand in two of the seven (29%) in group II. High signal intensity was not found in group III. The mean percentage of areas of high signal intensity was 11.86 +/-1 . 37 % in group Iand 5.18 +/-1 . 77% in group II( P <0.05). During histologic examination, occlusion of the distal branches of the anterior cerebral (ACA) and/or the middle cerebral arteries(MCA) by PVA particles was observed in all seven cats (100%) in group I, and in four of the seven cats (57%) in group II. No group IIIcat showed occlusion of the distal branches of the ACA and/or MCA. The mean caliber of occluded vessels was 175 micrometer in Group Iand 258 micrometer in Group II. The mean number of occluded vessels seen on all slide sections was 14 in Group I and 5 in Group II. CONCLUSION: Small PVA particles had a greater cerebral embolic effect than did those which were medium or large. For the induction of embolic infarction in cat brain, PVA particles 45-150 micrometer in size are appropriate.
Animals ; Brain ; Carotid Artery, Common ; Cats* ; Cerebral Arteries* ; Infarction ; Particle Size* ; Polyvinyl Alcohol* ; Polyvinyls*

PURPOSE: This study was designed to determine the embolic effect of PVA particles of various sizes on the cerebral artery of a cat and to determine the appropriate particle size for embolization. MATERIALS AND METHODS: A total of 21 cats were divided into three groups according to the PVA particle size injected: group I(n=7), embolized with 45-150 micrometer PVA; group II(n=7), with 150-250 micrometer PVA; and group III(n=7), with 350-500 micrometer PVA. PVA particles were slowly injected into the left common carotid artery of each cat, and T2-weighted coronal MR images were obtained 24 hours after injection. During histologic examination of brain sections we analyzed the size, number of occluded vessels, and the ischemic changes caused by the particles. RESULTS: On T2 weighted images, areas of high signal intensity (infarction) were observed in four of the seven cats (57%) in group Iand in two of the seven (29%) in group II. High signal intensity was not found in group III. The mean percentage of areas of high signal intensity was 11.86 +/-1 . 37 % in group Iand 5.18 +/-1 . 77% in group II( P <0.05). During histologic examination, occlusion of the distal branches of the anterior cerebral (ACA) and/or the middle cerebral arteries(MCA) by PVA particles was observed in all seven cats (100%) in group I, and in four of the seven cats (57%) in group II. No group IIIcat showed occlusion of the distal branches of the ACA and/or MCA. The mean caliber of occluded vessels was 175 micrometer in Group Iand 258 micrometer in Group II. The mean number of occluded vessels seen on all slide sections was 14 in Group I and 5 in Group II. CONCLUSION: Small PVA particles had a greater cerebral embolic effect than did those which were medium or large. For the induction of embolic infarction in cat brain, PVA particles 45-150 micrometer in size are appropriate.
Animals ; Brain ; Carotid Artery, Common ; Cats* ; Cerebral Arteries* ; Infarction ; Particle Size* ; Polyvinyl Alcohol* ; Polyvinyls*

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

Pectus excavatum is rare, but it is the most common type of sternal congenital disorder. There are many surgical methods to correct pectus excavatum such as the Ravitch method, Wada method, Silastic mold method, and the Nuss operation. We report a case of minimal invasive surgery for pectus excavatum using a polyvinyl alcohol sponge.
Congenital, Hereditary, and Neonatal Diseases and Abnormalities ; Dimethylpolysiloxanes ; Fungi ; Funnel Chest ; Polyvinyl Alcohol ; Polyvinyls ; Porifera