Resecting Lower Segment Inferior Vena Cava Leiomyosarcoma With Middle Segment Extension While Avoiding Renal Morbidity.

Primary leiomyosarcoma of the inferior vena cava (IVC) is a rare and aggressive mesenchymal tumor, with less than 400 reported cases to date. Complete resection of the tumor with clear margins is the only proven curative treatment, providing survival benefits. Nonetheless, leiomyosarcomas in the middle segment or those extending up to it within the inferior vena cava (IVC) frequently necessitate renal reimplantation or nephrectomy, with rates varying between 56% and 75%. In this case report, we present a 65-year-old female with lower segment IVC leiomyosarcoma with middle segment extension, successfully resected and reconstructed while avoiding associated renal reimplantation or nephrectomy morbidity.

Open Barrier Membrane Technique for the Treatment of Oroantral Communications: Two Case Reports.

Oroantral communications (OACs) are relatively common complications after extractions of maxillary posterior teeth. Some defects can heal spontaneously, while others require surgical treatment. The lack of an appropriate therapeutic approach can lead to the epithelialization of the OAC that causes a permanent connection between the two cavities, called an oroantral fistula (OAF), and subsequent chronic sinusitis. Various treatment modalities have been used in cases of OACs, including advancement flaps, bone grafts, synthetic materials, and barrier membranes. We present two cases of closure of OACs with dense polytetrafluoroethylene (d-PTFE) membranes (of FDI tooth #28 in the first case and #17 in the second case), which were left exposed to the oral cavity. In both cases, healing was uneventful.

Contact-Electro-Catalysis Through Electret Behavior to Facilitate Electron Transfer.

Contact-electro-catalysis (CEC) usually uses polymer dielectrics as its catalysts under mechanical stimulation conditions, which although has a decent catalytic dye degradation effect still warrants performance improvement. A carrier separation promotion strategy based on an internal electric field by polarization can effectively improve ferroelectric material performance in photocatalysis and piezocatalysis. Therefore, carrier separation as a necessary process of CEC also can be promoted and is largely expected to improve CEC performance theoretically. However, the carrier separation enhancement by the internal electric field strategy has not been achieved in the CEC experiment yet, because of the difficulty of building an internal electric field in an inert polymer dielectric. Herein, a polytetrafluoroethylene (PTFE) dielectric was charged through an electret process, which was believed to establish an internal electric field for CEC catalysts proved by KPFM, XPS, and triboelectric nanogenerator voltage output analysis. The fastest degradation rate of methyl orange reached over 90% at 1.5 h, while the hydroxyl free radical (•OH) yield of the PTFE electret was nearly three times that of the original PTFE. Density functional theory (DFT) calculations verified that the potential barrier of interatomic electron transfer between PTFE and H2O was reduced by 37% under the internal electric field. The electret strategy used herein to optimize the PTFE catalyst provides a base for the use of other general plastics in CEC and facilitates the production of easily prepared, easily recyclable, and inexpensive polymer dielectric catalysts that can promote large-scale pollutant degradation via CEC.

Detection and Visualization of Minor Irradiation-Induced Changes in Polytetrafluoroethylene (PTFE) by Raman Spectroscopy.

Exposure of polytetrafluoroethylene (PTFE) to argon plasma results in chemical modification of the polymer near the surface. Interestingly, PTFE modification can be induced by the sub-band gap ultraviolet (UV) irradiation. In the latter case, the changes in the chemical structure are very subtle, and they are practically invisible to conventional experimental techniques. Raman spectra of irradiated and raw samples show practically identical peaks. However, the baseline that is commonly considered as an unwanted spectral component contains an important information that reflects the minor structural changes. With the proper data analysis, this allows us to visualize the effects of the argon plasma and sub-band gap UV irradiation on the polymer.

Expanded Polytetrafluoroethylene Spacer for Nonpenetrating Deep Sclerectomy Combined with Cataract Surgery.

Purpose: To compare the outcomes of nonpenetrating deep sclerectomy (NPDS) with and without an expanded polytetrafluoroethylene (e-PTFE) implant combined with phacoemulsification (PE). Design: Interventional case series with concurrent control group. Materials and methods: Patients with medically uncontrolled glaucoma underwent PE nonpenetrating deep sclerectomy (NPDS) and were consecutively divided into a study group receiving an e-PTFE implant and a control group undergoing PE-NPDS. Intraocular pressure (IOP), corrected distance visual acuity (CDVA), and the number of glaucoma medications at 1 day, 1 week, 1 month, 3 months, and 6 months were recorded. Results: A total of 22 eyes of 16 patients underwent PE-NPDS, including 11 eyes receiving an e-PTFE implant and another 11 eyes with no implant. NPDS with spacer achieved successful results in all patients, including eight (72.7%) complete and three (27.3%) qualified success, 6 months, postoperatively. The corresponding values in the control group were 10 (90.9%) and 1 (9.1%), respectively. In the spacer group, mean IOP was decreased from 19.3 ± 2.8 at baseline to 12.1 ± 2.0 mm Hg at month 6 (p < 0.001). Corresponding values for the control group were 18.6 ± 3.4 and 10.6 ± 1.5 mm Hg, respectively (p < 0.001). Mean IOPs were comparable between the study groups at all time points. Implant exposure occurred in one of the patients in the study group. While the implant was extruded, the IOP was medically controlled. Conclusion: Outcomes of PE-NPDS using an e-PTFE implant were comparable to the same surgery without a spacer in the short term. Larger studies with longer follow-ups are needed to determine the efficacy and safety of this new implant. How to cite this article: Hajizadeh M, Meshksar A, Hassanpour K, et al. Expanded Polytetrafluoroethylene Spacer for Nonpenetrating Deep Sclerectomy Combined with Cataract Surgery. J Curr Glaucoma Pract 2024;18(2):51-56.

Application of Bovine Pericardium and Expanded Polytetrafluoroethylene Patches in Tricuspid Valvuloplasty after Cardiac Surgery.

Background: Leaflet augmentation is often required to correct an inadequate leaflet size due to leaflet thickening, contracture and junctional fusion in patients with tricuspid valve regurgitation (TR) after left-side valve surgery (LSVS). However, the ideal material for leaflet augmentation remains controversial. This article aims to compare the medium- and long-term results of tricuspid valve repair with bovine pericardium (BP) and expanded Polytetrafluoroethylene (ePTFE) patches for the augmentation of tricuspid leaflets and to compare the durability of the two materials. Methods: From January 2015 to April 2023, a total of 69 patients with severe isolated TR underwent tricuspid valvuloplasty (TVP) by leaflets augmentation with patches in our institute. According to the different types of patches, they were divided into the BP group (n = 44) and the ePTFE group (n = 25). Results: There were 3 perioperative deaths (4.3%), one case was due to low cardiac output syndrome in the BP group, and 2 cases were due to acute respiratory dysfunction syndrome and low cardiac output syndrome in the ePTFE group, respectively. Before discharge, the area of the TR jet on echocardiography decreased from 23.5 ± 9.1 to 4.2 ± 3.4 cm 2 . One case in each group was found to have increased blood flow velocity at the tricuspid orifice. After discharge, one patient in each group underwent repeat TVP, in the BP group because of shortened chordae and in the ePTFE group because of calcification of the patch. During the entire follow-up period, there were 7 cases of severe TR (10.1%), 5 in the BP group and 2 in the ePTFE group, a total of 5 cases of tricuspid stenosis (7.2%), 4 in the BP group and 1 in the ePTFE group, and a total of 6 deaths (8.7%), 5 in the BP group and 1 in the ePTFE group. Transthoracic ultrasound in a patient with tricuspid stenosis suggests stiff leaflet movement and poor motion. Conclusions: Leaflet patch enlargement can be safely used in tricuspid valve repair, but BP patches carry a risk of reduced flexibility and stiffness of movement, and ePTFE patches carries a risk of calcification.

Diaphragmatic and pericardial reconstruction using a Gore-Tex® patch in a patient with an invasive liver malignancy.

The Gore-Tex® polytetrafluoroethylene patch is one of the most used prostheses for diaphragm, vessel, and pericardial reconstruction. It is strong, flexible, and relatively inexpensive and can be fitted to match the size of the resected area. In addition, it can be used to reconstruct the pericardium and diaphragm following resection to treat diffuse malignant pleural mesothelioma or repair large hiatal hernias. However, the use of polytetrafluoroethylene for hepatocellular carcinoma with diaphragmatic and pericardial invasion has not yet been reported. We report the case of a 72-year-old man with hepatocellular carcinoma with diaphragmatic and pericardial invasion. Subsequently, laparotomic liver subsegmentectomy of segment 3 and resection of the diaphragm and pericardium were performed. The defects were successfully reconstructed using the polytetrafluoroethylene patch, without postoperative complications. This is the first report describing a case of invasive liver malignancy that required simultaneous diaphragmatic and pericardial reconstruction using a polytetrafluoroethylene patch, indicating that the polytetrafluoroethylene patch could effectively and directly treat invasive liver malignancies.

Long-term outcomes of below-the-knee bypass surgery using heparin-bonded expanded polytetrafluoroethylene grafts.

PURPOSE: To report the outcomes of below-the-knee (BK) bypass surgery using heparin-bonded expanded polytetrafluoroethylene (ePTFE) grafts, performed in two centers since its launch in Japan. METHODS: We conducted a retrospective analysis of databases from two medical centers, evaluating 51 limbs in 42 consecutive patients with peripheral arterial disease (PAD), who underwent BK bypass surgery using heparin-bonded ePTFE grafts between October, 2013 and April, 2023. RESULTS: Thirty-three limbs (64.7%) were classified as Rutherford category 4-6 and 33 limbs (64.7%) had a history of ipsilateral revascularization. Technical success was achieved in 98% of the patients. The 30 day mortality rate was 2.4% (n = 1) and the overall 30 day complication rate was 9.5% (n = 4). The median follow-up period was 38 (interquartile range 13-67) months. Three patients required major amputation and 14 died during follow-up. Primary patency rates at 1, 3, and 5 years were 67.8%, 57.5%, and 46.5%, respectively, while secondary patency rates for these periods were 84.6%, 70.0%, and 66.0%, respectively. Overall survival rates at 1, 3, and 5 years were 90.1%, 74.5%, and 70.9%, respectively. CONCLUSIONS: BK bypass surgery using heparin-bonded ePTFE graft is a viable and durable option for patients with PAD, who are deemed unsuitable for autologous vein bypass surgery.

Systematic literature review comparing clinical utility of heparin-bonded expanded polytetrafluoroethylene graft with autologous saphenous vein graft for the management of below-the-knee peripheral arterial disease.

BACKGROUND: This systematic literature review compares the clinical outcomes of heparin-bonded expanded polytetrafluoroethylene with autologous saphenous vein in the management of patients undergoing below-the-knee bypass to treat peripheral arterial disease. METHODS: An electronic literature search was conducted in MEDLINE and Embase to identify comparative studies in patients who underwent below-the-knee surgical bypass. Studies were screened at abstract and full text review using predefined inclusion criteria by two independent reviewers and critically appraised for risk of bias. Meta-analyses were conducted using Review Manager 5 software (Nordic Cochrane Centre). RESULTS: Eight retrospective cohort studies were identified. Meta-analysis of primary patency demonstrated no significant difference between heparin-bonded expanded polytetrafluoroethylene and autologous saphenous vein grafts after 1 (odds ratio: 0.91, 95% confidence interval: [0.52-1.59]; P = .74), 2 (1.12 [0.60-2.10]; P = .77), 3 (0.62 [0.26-1.48]; P = .28), and 4 years (0.70 [0.36-1.39]; P = .31). Similarly, for secondary patency, no significant difference was detected at 1 (0.62 [0.33-1.15]; P = .13), 2 (0.83 [0.32-2.13]; P = .69), 3 (0.60 [0.27-1.32]; P = .20), and 4 years (0.66 [0.32-1.36]; P = .26). There was no significant difference between autologous veins and heparin-bonded expanded polytetrafluoroethylene for limb salvage and mortality at all time points. A sensitivity analysis to compare outflow vessels was conducted in only tibial bypass and identified no differences. All analyses were considered at high-risk bias because of heterogeneity in study populations and attrition in follow-up. CONCLUSIONS: This meta-analysis demonstrates similar outcomes between autologous saphenous vein and heparin-bonded expanded polytetrafluoroethylene for patency, limb salvage, and mortality through 4 years. The use of heparin-bonded expanded polytetrafluoroethylene synthetic grafts is a satisfactory option to prevent amputation, particularly when autologous saphenous vein grafts are not available. Controlled clinical studies are needed to further inform future decision-making and economic modeling related to the choice of conduit for below-the-knee graft construction.

Prophylactic splenic artery embolization using n-butyl-2-cyanoacrylate and coils prior to endoscopic necrosectomy in a patient with necrotizing pancreatitis: A case report.

We present a case of prophylactic endovascular embolization in a 51-year-old man with necrotizing pancreatitis (NP) before undergoing endoscopic necrosectomy (EN). Contrast-enhanced CT imaging revealed the presence of a walled-off necrosis (WON) surrounding the pancreas, with the splenic artery coursing through the cavity. The splenic artery was embolized using n-butyl-2-cyanoacrylate (NBCA) and coils to mitigate the risk of massive bleeding in EN. A newly developed polytetrafluoroethylene (PTFE)-coated microcatheter was used to inject NBCA, enabling embolization of a long segment of the splenic artery without adhering to the vessel wall. Coils were placed distal and proximal to the embolized segment to optimize control. Over 5 sessions of EN, no massive bleeding was encountered. This report demonstrates the benefits of utilizing PTFE-coated microcatheters for enhanced safety and maneuverability during embolization with NBCA. Furthermore, it highlights the importance of prophylactic embolization during EN for managing NP.

Effect of ultraviolet aged polytetrafluoroethylene microplastics on copper bioavailability and Microcystis aeruginosa growth.

Microplastics (MPs) are ubiquitous in aquatic environments, which can act as carriers to affect the bioavailability of heavy metals. The aging process in the environment changes the physicochemical properties of MPs, thereby affecting their environmental behavior and co-toxicity with other pollutants. However, relevant research is limited. In this study, we compared the properties and Cu2+ adsorption capacity of pristine and aged polytetrafluoroethylene (PTFE) MPs and further explored the influence on copper bioavailability and bio-effects on Microcystis aeruginosa. Aging process induced surface oxidation and cracks of PTFE MPs, and decreased the stability of MPs in water by increasing zeta potential. PTFE MPs had a strong adsorption capacity for Cu2+ and increased the bioavailability of copper to microalgae, which was not affected by the aging process. Pristine and aged PTFE MPs adhered to cyanobacterium surfaces and caused shrinkage and deformation of cells. Inhibition of cyanobacterium growth, photosynthesis and reduction of total antioxidant capacity were observed in the treatment of PTFE MPs. Combined exposure of pristine MPs and Cu2+ had stronger toxic effects to cyanobacterium, and increased Microcystin-LR release, which could cause harm to aquatic environment. Aging reduced the toxic effects of PTFE MPs on microalgae. Furthermore, soluble exopolysaccharide (EPS) content was significantly higher in co-exposure of aged MPs and Cu2+, which could reduce the toxicity to cyanobacterium cells. These results indicate that aging process alleviates the toxicity to microalgae and environmental risks caused by PTFE MPs. This study improves understanding of the combined toxicity of aged MPs and metals in freshwater ecosystems.

Use of Flow Restrictors in Congenital Heart Disease.

The surgical pulmonary artery band was first introduced in 1952 and, to this day, can produce challenges in regard to the ideal amount of restriction and the need for reoperations. A transcatheter option may be the ideal solution as it allows for a less-invasive approach for a better hemodynamic assessment and easier re-intervention. To date, multiple approaches have been developed with device modifications to create restrictions to flow, each with advantages and limitations. Continued experience is still necessary to determine the ideal device to use to create an adequate and modifiable level of restriction.

Sustainable H2O2 production in a floating dual-cathode electro-Fenton system for efficient decontamination of organic pollutants.

Electrochemical advanced oxidation processes (EAOPs) based on natural air diffusion electrode (NADE) promise efficient and affordable advanced oxidation water purification, but the sustainable operation of such reaction systems remains challenging due to severe cathode electrowetting. Herein, a novel floating cathode (FC) composed of a stable hydrophobic three-phase interface was established by designing a flexible catalytic layer of FC. This innovative electrode configuration could effectively prolong the service life of the cathode by mitigating the interference of H2 bubbles from the hydrogen evolution reaction (HER), and the H2O2 production rate reached 37.59 mg h-1·cm-2 and realize a long-term stable operation for 10 h. Additionally, an FC/carbon felt (CF) dual-cathode electro-Fenton system was constructed for in situ sulfamethoxazole (SMX) degradation. Efficient H2O2 production on FC and Fe(III) reduction on CF were synchronously achieved, attaining excellent degradation efficiency for both SMX (ca. 100%) with 2.5 mg L-1 of Fe(Ⅱ) injection. For real wastewater, the COD removal of the FC/CF dual-cathode electro-Fenton system was stabilized at exceeding 75%. The practical application potential of the FC/CF dual-cathode electro-Fenton system was also demonstrated for the treatment of actual landfill leachate in continuous flow mode. This work provides a valuable path for constructing a sustainable dual-cathode electro-Fenton system for actual wastewater treatment.

Elucidating the Benefit of Perforated vs Non-Perforated Membranes in Guided Bone Regeneration: An in Vivo Histologic Evaluation and Histomorphometric Analysis.

BACKGROUND: Non-perforated Polytetrafluoroethylene (PTFE) membranes are effectively utilized in guided bone regeneration (GBR) but may hinder cell migration due to limited interaction with the periosteum. This study compared bone regeneration using occlusive or perforated membranes combined with acellular collagen sponge (ACS) and recombinant human bone morphogenic protein-2 (rhBMP-2) in a canine mandibular model. MATERIAL AND METHODS: Male beagle dogs (n=3) received two mandibular defects each to compare ACS/rhBMP-2 with experimental (perforated group) and control (non-perforated group) membranes (n=3 defects/group). Tissue healing was assessed histomorphologically, histomorphometrically and through volumetric reconstruction using microcomputed tomography. RESULTS: The perforated group showed increased bone formation and reduced soft tissue formation compared to the non-perforated group. For the primary outcome, histomorphometric analysis revealed significantly greater total regenerated bone in the perforated group (67.08 ± 6.86%) relative to the nonperforated group (25.18 ± 22.44%) (p = 0.036). Perforated membranes had less soft tissue infiltration (32.91 ± 6.86%) compared to non-perforated membranes (74.82 ± 22.44%) (p = 0.036). CONCLUSION: The increased permeability of membranes in the perforated group potentially enabled periosteal precursor cells greater accessibility to rhBMP-2. The availability may have accelerated their differentiation into mature bone-forming cells, contributing to the stimulation of new bone production, relative to the non-perforated group.

Effect of Organic and Inorganic Nanoparticles on Colour Stability and Mechanical Properties of Heat Vulcanised Maxillofacial Silicone Elastomer: a Comparative Study.

Objectives: The purpose of this comparative study in vitro was to evaluate the effect of organic and inorganic nanoparticles on colour stability, tear strength and hardness of maxillofacial silicone elastomer at baseline and when subjected to outdoor weathering for 6 months. Material and Methods: A total of 240 specimens were fabricated using M511 platinum silicone which were divided into total 4 groups (n = 60) based on the type of nanoparticles (control, polytetrafuoroethylene [PTFE], titanium dioxide [TiO2], zinc oxide [ZnO]) added and each group was further divided into 3 subgroups (n = 20) for colour, tear strength (TS) and hardness (H) testing. The tests were conducted and data was obtained both before and after outdoor weathering of 6 months. Results: Minimum colour change after weathering was observed in PTFE group (∆E = 2.23). TiO2 group showed maximum TS (12.01 N/mm) followed by PTFE group (10.85 N/mm) before weathering. After weathering, maximum TS was shown by TiO2 group (12.9 N/mm) and PTFE group (12.54 N/mm). TiO2 group showed maximum hardness (24.15 shore A) before weathering and PTFE group showed maximum hardness (33.43 shore A) after weathering. Conclusions: Within the limitations of this study, it can be concluded that the addition of polytetrafuoroethylene nanoparticles to the polymer enhances both the optical as well as mechanical properties and can be considered favourable for the extended life of the prosthesis.

Tribological and Mechanochemical Properties of Nanoparticle-Filled Polytetrafluoroethylene Composites under Different Loads.

For the tribological properties of nanoparticle-modified PTFE, a more comprehensive study has been conducted, but there is still some room for research on tribology behavior, tribofilm formation and structure evolution of polytetrafluoroethylene (PTFE) filled with α-Al2O3 and SiO2 nanoparticles during sliding against steel counterparts under different loads. At the same time, it establishes the linkage and mechanism between the maintenance of mechanical strength and the tribological application of polymers in service and provides corresponding scientific data and theoretical guidance for the long-lasting application of polymer lubrication materials. It is found that both composites exhibit good wear resistance across the pressure of 1 MPa to 10 MPa, with the α-Al2O3/PTFE composite demonstrating better performance stability compared to the SiO2/PTFE composite. The high wear resistance is attributed to the formation of tribofilms at the friction interface. For the α-Al2O3/PTFE, an island-like tribofilm is formed with a thickness ranging from 100 to 200 nm, while the tribofilm of the SiO2/PTFE composite is thinner, measuring approximately 50 to 100 nm, and manifests a striped pattern. The chemical composition, both at the surface and subsurface levels, as well as the morphology of the tribofilms, were studied using FTIR spectrometry, X-ray photoelectron spectroscopy (XPS), and FIB-TEM. It is found that the difference in thickness and microstructure of the tribofilms for the two composites is mainly due to the tribochemistry of the nanoparticles. The α-Al2O3 nanoparticle plays a "cohesion" role during the formation of the tribofilm, which facilitates the formation of a thicker, more uniform, and stronger adhered tribofilm on the metallic counterpart, making it more robust against higher shear stress.

A Study on the Effect and Suppression of Hydrogen Permeation Behavior on the Friction Characteristics of PEEK/PTFE Composites via Molecular Dynamics Simulation.

To research the effect of hydrogen permeation on the friction characteristics of the seal materials on the hydrogen equipment, the molecular models of 10% PEEK/PTFE composites and its frictional models were established, respectively, and molecular dynamics (MDs) and giant canonical Monte Carlo (GCMC) methods were used to simulate the diffusion coefficient, dissolution coefficient and permeability coefficient of the hydrogen in PEEK/PTFE composites. The effect of a different amount of hydrogen on the friction and wear of PEEK/PTFE composites was also studied. The results showed that few permeations of the hydrogen gas mainly demonstrated having a positive effect on the surface of the PEEK/PTFE composites, and the wear rate of the PEEK/PTFE composites showed a slight decreasing trend. The wear rate of the PEEK/PTFE composites gradually decreased when more hydrogen molecules penetrated the matrix. With the further penetration of the hydrogen molecules, the wear rate and friction coefficient of the PEEK/PTFE composites rapidly increased, showing a negative effect. With the further penetration of the hydrogen molecule, the friction coefficient of the composite displayed a small fluctuation and then a rapid decreasing trend. Meanwhile, effective improvement measures were proposed, and the introduction of the graphene was verified to be effective to reduce the negative effect of the hydrogen permeation, thereby improving the friction performance of the PEEK/PTFE composites.

Long-Term Outcomes of a Japanese Prospective Multicenter Registry Using a Heparin-Bonded Expanded Polytetrafluoroethylene Graft for Above-the-Knee Femoropopliteal Bypasses.

BACKGROUND: Despite the widespread use of PROPATEN®, a bioactive heparin-bonded expanded polytetrafluoroethylene graft, in bypass surgery, there are only a few reports of long-term results. We evaluated the long-term results of PROPATEN®use for above-knee femoropopliteal bypass (AKFPB).Methods and Results: After PROPATEN®-based AKFPB, patients were prospectively registered at 20 Japanese institutions between July 2014 and October 2017 to evaluate long-term results. During the median follow-up of 76 months (interquartile range 36-88 months) for 120 limbs (in 113 patients; mean [±SD] age 72.7±8.1 years; 66.7% male; ankle-brachial index [ABI] 0.45±0.27; lesion length 26.2±5.7 cm; chronic limb-threatening ischemia in 45 limbs), there were 8 major amputations; however, clinical improvement was sustained (mean [±SD] ABI 0.87±0.23) and the Rutherford classification grade improved in 105 (87.5%) limbs at the latest follow-up. At 8 years, the primary patency, freedom from target-lesion revascularization, secondary patency, survival, and amputation-free survival, as estimated by the Kaplan-Meier method, were 66.3±4.8%, 71.5±4.4%, 86.5±3.4%, 53.1±5.0%, and 47.4±5.3%, respectively. CONCLUSIONS: This multicenter prospective registry-based analysis showed sustained excellent clinical improvement and secondary patency for up to 8 years following PROPATEN®-based AKFPB. PROPATEN®constitutes a durable and good revascularization option for complex superficial femoral artery lesions, especially when endovascular treatment is inappropriate or an adequate venous conduit is unavailable.

Piezoelectric and Dielectric Electrospun Fluoropolymer Membranes for Oral Mucosa Regeneration: A Comparative Study.

Wound healing of the oral mucosa is an urgent problem in modern dental surgical practice. This research article presents and compares the findings of the investigations of the structural, physicochemical, and biological characteristics of two types of polymeric membranes used for the regeneration of oral mucosa. The membranes were prepared from poly(tetrafluoroethylene) (PTFE) and a copolymer of vinylidene fluoride and tetrafluoroethylene (VDF-TeFE) and analyzed via scanning electron microscopy, atomic force microscopy, X-ray diffraction analysis, and Fourier transform infrared spectroscopy. Investigation results obtained indicate that both types of membranes are composed of thin fibers: (0.57 ± 0.25) µm for PTFE membranes and (0.43 ± 0.14) µm for VDF-TeFE membranes. Moreover, the fibers of VDF-TeFE membranes exhibit distinct piezoelectric properties, which are confirmed by piezoresponse force microscopy and X-ray diffraction. Both types of membranes are hydrophobic: (139.7 ± 2.5)° for PTFE membranes and (133.5 ± 2.0)° for VDF-TeFE membranes. In vitro assays verify that both membrane types did not affect the growth and division of mice fibroblasts of the 3T3-L1 cell line, with a cell viability in the range of 88-101%. Finally, in vivo comparative experiments carried out using Wistar rats demonstrate that the piezoelectric VDF-TeFE membranes have a high ability to regenerate oral mucosa.

Histological Evaluation of Alveolar Ridge Preservation Using Different Bone Grafts: Clinical Study Analysis Part II.

To compare histologically the percentage of bone formation 12-20 weeks after ridge augmentation using 2 different techniques. Tooth loss is associated with 3-dimensional bone remodeling and ridge atrophy. Ridge preservation procedures can prevent alveolar bone volume loss. Different techniques and materials are used to preserve the alveolar ridge. Computer-generated randomization software was used to assign 2 ridge preservation techniques for 11 extraction sites. In group I, type I bovine Achilles tendon collagen plugs with bioactive resorbable calcium apatite crystals (CPCAC) were placed, and in group II, cortico-cancellous bone chips (CCBC) mix and an expanded polytetrafluoroethylene (ePTFE) barrier membrane were placed. The histomorphometric studies were performed using a computer-based image analysis system (ImageJ 1.4, National Institute of Health, Bethesda, Md) to calculate the pixel area of bone tissue and the remaining bone graft material. The histomorphometric data were analyzed using a Student t test to compare the measurements between the 2 experimental groups. This parametric statistical test was employed to determine if there were any statistically significant differences in the quantitative histological parameters between the groups. The sockets that received CPCAC showed a lower (31.89%) percentage of native bone surface area compared with the CCBC group (43.87%). However, the difference was not statistically significant (P < .05). In addition, the CPCAC group showed evidence of foreign-body reaction. The CCBC graft covered with an ePTFE barrier may induce more bone formation with minimal inflammation in an extraction socket compared with a collagen plug with calcium apatite crystals. In addition, histological analysis of the CPCAC graft showed evidence of foreign-body reaction, which indicates a negative clinical impact.