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OBJECTIVE: The purpose of this article is to highlight the risk of pseudoaneurysms formation after orthognathic surgery, their clinical features and management.
METHODS: A case report of a 24-year-old man who suffered a pseudoaneurysm of the internal maxillary artery after sagittal osteotomy during orthognathic is reported. After three bleeding episodes, a pseudoaneurysm was diagnosed with a computed tomography angiogram (CTA) and treated with an embolization of the internal maxillary artery with polyvinyl alcohol (PVA) successfully.
RESULTS: Pseudoaneurysms derived from the external carotid artery are an uncommon complication of orthognathic surgery, especially related to sagittal osteotomy instead of LeFort I osteotomy.
CONCLUSIONS: Pseudoaneurysms derived from external carotid artery branches must be suspected when patients show multiple episodes of bleeding (epistaxis or through the surgical approach) within the first two weeks after orthognathic surgery. If so, vascular CT or angiography should be performed to rule out the presence of vascular injuries. In case a pseudoaneurysm is identified, vascular embolization with N-butyl-cyanoacrylate seems to be the best treatment if available. If this treatment is not available or bleeding cannot be controlled, surgical ligature of the injured vessel is a valid treatment.

BACKGROUND: Renal artery embolization aims to reduce blood loss during surgery. Various embolizing agents are available, each of which has its own indications appropriate for various vascular anatomy and renal pathology.
METHODS: We report three cases of renal artery embolization prior to surgical nephrectomy using vascular plug and other embolizing agents. In two cases, complete blood flow occlusion was achieved with minimal blood loss during the subsequent surgery. One case only achieved reduced blood flow, but subsequent nephrectomy and patient recovery was successful.
CONCLUSIONS: Renal artery embolization prior to malignant mass resection is a well-known, potentially beneficial procedure. The rationale that supports this procedure is clear, but its reported outcome in the literature is still inconclusive. It is important to understand its benefits, complications, and pitfalls to achieve better outcome.
CONCLUSIONS: In our cases, renal artery embolization provided satisfactory reduction in bleeding during nephrectomy, and therefore has the potential to be employed as a standard procedure for future surgeries.

Adding small molecular plasticizers is the most common route to tailor the stretchability of poly(vinyl alcohol) (PVA). However, how the plasticization along with the nature of the plasticizer governs the structural homogeneity during stretching remains an open question to answer. Herein, two representative plasticizers, glycerol (GLY) and water, are chosen to endow the PVA films with ductility. It is found that large strain cavitations cause obvious stress whitening in the PVA/H2 O films; on the contrary, most of the PVA/GLY films maintain transparent undergoing tensile deformation. Through a combination of experimental inspections and molecular dynamic simulation, it is revealed that partial water molecules that behave as free water will aggregate into microdomains, which serve as mechanical defects responsible for yielding voids. Whereas, the GLY plasticizer homogeneously disperses at a molecular level and interacts with PVA chains through strong hydrogen bonds. More interestingly, it is illustrated that the dispersion and bound states of plasticizers are closely related to the mechanical character of the plasticized PVA films. These findings offer new insight into the working mechanism of plasticization on the structural stability during stretching, and guide the design of PVA/plasticizer system to obtain excellent comprehensive mechanics.

Despite the pollution induced by plastics become a well-known and documented problem, bringing many countries to adopt restrictions about their production, commercialization and use, the impact of another emerging category of synthetic polymers, represented by the Water-Soluble Polymers (WSPs), also known as \"liquid plastics\", is overlooked by scientific community. WSPs are produced in large quantities and used in a wide plethora of applications such as food packaging, pharmaceuticals and personal care products, cosmetics and detergents, with a consequent continuous release in the environment. The aim of this study was the investigation of the possible toxicity induced by polyvinyl alcohol (PVA), one of the main produced and used WSPs, on two freshwater model organisms, the crustacean Daphnia magna and the teleost Danio rerio (zebrafish). We evaluated the effects of solubilized standard PVA powder and PVA-based commercial bags for carp-fishing, at 3 different concentrations (1 µg/L, 0.5 mg/L and 1 mg/L), through the exposures for 14 days of D. magna (daphnids; age < 24 h) and for 5 days of zebrafish embryos (up to 120 h post fertilization - hpf). As acute effects we evaluated the immobilization/mortality of specimens, while for chronic toxicity we selected several endpoints with a high ecological relevance, as the behavioural alteration on swimming performance, in real-time readout, and the activity of monoamine oxidase (MAO), a neuro-enzyme with a potential implication in the organism movement. The results showed the lack of significant effects induced by the selected substances, at all tested concentrations and in both model organisms. However, considering the wide plethora of available WSPs, other investigations are needed to provide the initial knowledge of risk assessment of these compounds contained in some consumer products.

A little is known about the link between the macromolecular architecture of dialdehyde polysaccharides (DAPs), their crosslinking capabilities, and the properties of resulting hydrogels. Here, DAPs based on cellulose, dextrin, dextran, and hyaluronate were compared as crosslinkers for poly(vinyl alcohol), PVA. The swelling, network parameters, viscoelastic properties, porosity, and cytotoxicity of PVA/DAP hydrogels were investigated concerning the crosslinker structure, molecular weight, aldehyde group density per macromolecule, and the size of spontaneously formed crosslinker nano-assemblies. Generally, crosslinkers based on linear polysaccharides (cellulose, hyaluronate) performed more reliably, while the presence of branching could be both beneficial (dextran) but also detrimental (dextrin) at lower crosslinker concentrations. For example, the hydrogel swelling differed by up to one-third (600 vs. 400%) and storage modulus even by up to one half (~7000 vs. ~3500 Pa) depending on crosslinker structure and properties. These differences were rationalized by variances in crosslinking modes derived based on obtained data.

In 2016, the U.S. Food and Drug Administration approved the first and only polyvinyl alcohol hydrogel implant for the treatment of hallux rigidus. The implant functions as a bumper to maintain first metatarsophalangeal joint space to prevent contact of the phalangeal base with the first metatarsal head. Short-term and intermediate outcomes with this implant have reported positive outcomes with no radiographic outcomes of implant wear or subsidence. We performed a retrospective radiographic review of 27 consecutive patients who received the implant and measured preoperative and postoperative joint space area (JSA). We found a significant improvement in JSA (p < .001) between the preoperative JSA and JSA at the first postoperative visit at 1 to 2 weeks. We also found a significant decrease in JSA (p < .001) between the first postoperative visit and the second postoperative visit at 5 to 12 weeks. This information could have further implications for implant design as well as how we can better achieve functional improvements in the first metatarsophalangeal joint in patients with hallux rigidus.

A novel microorganism embedding material was developed to enhance the benzene removal through adsorption and biodegradation, by introducing β-cyclodextrin (CD) to traditional polyvinyl alcohol gel beads. Results show that the optimal ratio of sucrose/benzene was 1.25 for co-metabolism biodegradation of benzene, and the maximum exogenous microbial respiration rate was 260.13 mgO2/(gVSS h) for gel beads with CD. The positive effects of CD on benzene removal mainly resulted from the adsorption characteristics of CD as well as the stimulation of CD on microbial activity. Adsorption tests indicate that CD addition increased the adsorption function of gel beads to benzene with its dispersion coefficient of 5.1 × 10-7 cm2/s. Respiration tests show that gel beads with CD possessed the highest maximum specific exogenous respiration rates. Moreover, a high-throughput sequencing analysis confirms that CD addition could obviously enhance microbial diversity with domain microbial of Zoogloea (17.0%). Finally, microbial embedding gel beads could remove certain benzene after lyophilization and storage for one month. Overall, the novel microbial embedding gel beads modified with CD (a favorable additional agent to traditional embedding materials) have been proved as an efficient method for removing benzene under suitable sucrose/benzene ratio.

OBJECTIVE: Hemangiopericytomas (HPCs) are rare dural-based neoplasms. Preoperative embolization of these notoriously hypervascular tumors can be challenging as they often receive their dominant blood supply from pial feeders arising from the internal carotid artery (ICA) or vertebrobasilar (VB) circulation. This study reviews our historical experience with HPC embolization and introduces the transtumoral technique for backfilling pial tumor vasculature by delivering Onyx-18 through diminutive external carotid artery (ECA) feeders.
METHODS: A retrospective review of all preoperative HPC embolizations performed at Anonymous University #1 (September 2002-November 2014) and Anonymous University #2 (January 2014-November 2014) is presented.
RESULTS: Fifteen patients with pathologically confirmed HPC underwent 17 embolizations. More extensive devascularization percentages were achieved for HPCs with primarily ECA blood supply (76.4±10.7%; n=6) than with HPCs supplied via the ICA/VB circulation (57.9±26.9%; n=8; p=0.046). There was a trend towards greater devascularization of ICA/VB-dominant HPCs embolized with Onyx (70.0±34.6%; n=4) versus polyvinyl alcohol particles (33.3±15.3%; n=3). The extent of angiographic devascularization negatively correlated with intraoperative blood loss (rho=-0.71; p=0.005). There were no embolization-related complications.
CONCLUSIONS: The extent of preoperative embolization of HPCs correlates with decreased intraoperative blood loss. However, HPCs with an ICA/VB-dominant blood supply remain challenging embolization targets, demonstrating reduced devascularization percentages compared with ECA-dominant counterparts. The authors favor the use of Onyx for ICA/VB-dominant HPCs, noting a trend towards an improved devascularization rate.

Juvenile nasopharyngeal angiofibroma (JNA) is a benign, vascular, and locally aggressive tumor that arises in the nasal cavity, extending into the nasopharynx and often in to the orbit. It may rarely present to the ophthalmologist with proptosis and optic neuropathy. Preoperative embolization of JNA is done before surgical resection. In this communication, the authors report a rare occurrence of ipsilateral central retinal artery occlusion (CRAO) following embolization with polyvinyl alcohol in a 13-year-old boy with right-sided JNA. Retrospective review of the angiograms pointed out to a suspicious communication between the external carotid artery and the ophthalmic vessels. Pre-embolization detailed study of the angiograms is necessary to avoid such devastating complications. Although rare, vision loss is a possible complication arising from embolization of nasopharyngeal and intracranial tumors, and all patients undergoing these procedures should be informed of the risk of visual loss because it has a lasting impact on the quality of life.