1.Preoperative Embolization of Extra-axial Hypervascular Tumors with Onyx.
Matthew R FUSCO ; Mohamed M SALEM ; Bradley A GROSS ; Arra S REDDY ; Christopher S OGILVY ; Ekkehard M KASPER ; Ajith J THOMAS
Journal of Cerebrovascular and Endovascular Neurosurgery 2016;18(1):12-18
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
2.Carvacrol-loaded polyvinyl alcohol/montmorillonite clay nanocomposite (PVA/MONT/Carva) as an antimicrobial agent for wound dressing
Nur Rifqah Attifah Rosman ; Woei Yenn Tong ; Syarifah Ab Rashid ; Nor Adilah Norodin ; Suzana Wahidin ; Wen Nee Tan ; Chean Ring Leong
Malaysian Journal of Microbiology 2021;17(4):352-360
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
3.A Case of Congenital Renal Arteriovenous Malformation.
Chang Sup HAN ; Sung Young LEE ; Kyung Seek PARK ; Sung Hyup CHOI
Korean Journal of Urology 1987;28(3):473-476
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
4.Research Progress of Polyvinyl Alcohol (PVA) Based on Hydrogel Dressings.
Ying HAN ; Yuyin XU ; Linqi TIAN ; Jing ZHOU ; Xiaoting ZHOU
Chinese Journal of Medical Instrumentation 2018;42(6):437-439
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
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Hydrogels
;
Polyvinyl Alcohol
;
Tensile Strength
;
Wound Healing
5.Three Cases of Endoscopic Reduction of Medial Blowout Fracture with Sinusitis and Nasal Polyp.
Tae Young JUNG ; Jae Woon WE ; Jae Hwan KWON
Korean Journal of Otolaryngology - Head and Neck Surgery 2012;55(4):246-249
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
6.Effect of Number of Measurement Points on Accuracy of Muscle T2 Calculations.
Noriyuki TAWARA ; Atsushi NISHIYAMA
Investigative Magnetic Resonance Imaging 2016;20(4):207-214
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
7.An Airway Tube for Minimizing Nasal Obstruction Following Intranasal Packing.
Nam Sik JOE ; Jung Hee YOON ; Jong Yeup KIM ; Min Wook KIM ; Jong Cheol CHOI ; Yeong Seok YUN
Journal of Rhinology 2008;15(1):48-54
BACKGROUND AND OBJECTIVES: Nasal packing after nasal surgery is commonly practiced for various purposes including hemostasis, stabilization of nasal structure, and synechia prevention. However, the use of nasal packing has led to the development of uncomfortable symptoms such as nasal obstruction. In this study, therefore, we have devised a new method of nasal packing involving the use of an airway tube for reducing nasal obstruction and discomforts in association with post-surgical nasal obstruction. Materials and METHODS: An airway tube was made by cutting the distal end of a 1cc syringe. It was inserted between the nasal septum and the packing material. Nasal cavities of 20 patients (Group 1) who underwent nasal surgery were packed using packing materials and the devised airway tubes following nasal surgery. We evaluated the symptoms of nasal obstruction after the postoperative nasal packing in this study group and compared them with those of the 20 patients (Group 2) who received packing with existing merocel nasal stents and 20 patients (Group 3) who were given packing with only merocel without airway tubes after nasal surgery. RESULT: In this study, nasal obstruction and discomforts in association with post-surgical nasal obstruction were significantly improved among patients given packing material and devised airway tubes (Group 1) comparative to other patient groups. CONCLUSION: Devised airway tube is useful in minimizing the symptoms of nasal obstruction and discomforts as well as in reducing surgical expense.
Formaldehyde
;
Hemostasis
;
Humans
;
Nasal Cavity
;
Nasal Obstruction
;
Nasal Septum
;
Nasal Surgical Procedures
;
Polyvinyl Alcohol
;
Stents
;
Syringes
8.Preparation and performance characterization of electrospun drug loaded poly (vinyl alcohol)/chitosan nanofibrous membrane.
Yani ZHANG ; Shanwei WU ; Jiayao XU ; Wei CHEN ; Yuanyuan LV
Journal of Zhejiang University. Medical sciences 2013;42(6):644-648
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.
Chitosan ; chemical synthesis ; Drug Carriers ; Membranes, Artificial ; Nanofibers ; Polyvinyl Alcohol ; chemical synthesis
9.The appraisal of mechanical properties and friction coefficient of PVA hydro-gel.
Liqi CHEN ; Dekun ZHANG ; Jinsong ZHANG
Journal of Biomedical Engineering 2009;26(5):1021-1024
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
10.Superselective Embolization of Renal Angiomyolipoma.
Jae Hoon LIM ; Young Tae KO ; Dong Ho LEE ; Joo Won LIM ; Yup YOON ; Tae Hoon KIM
Journal of the Korean Radiological Society 1994;30(3):549-554
PURPOSE: Authors retrospectively evaluated the efficacy of superselective renal arterial emboliation in 5 patients with symptomatic renal angiomyolipoma. MATERIALS AND METHODS: Five Patients with renal angiomyolipoma who had been treated with superselective renal arterial embolization were analysed retrospectively. Two patients who had multiple bilateral lesions were associated with tuberous sclerosis. The mbolic materials used were absolute alcohol in 6 sessions, absolute alcohol mixed with lipiodol in one session, and polyvinyl alcohol in one session. RESULTS: We could observe devascularization of the tumor on the post-embolization arteriograms. The symptoms such as flank pain were improved in all patients during the follow-up period of 3 months to 3years. CONCLUSION: Superselective renal arterial embolization is an effective and safe procedure in the management of renal angiomyolipomas.
Angiomyolipoma*
;
Ethanol
;
Ethiodized Oil
;
Flank Pain
;
Follow-Up Studies
;
Humans
;
Polyvinyl Alcohol
;
Retrospective Studies
;
Tuberous Sclerosis