Mean Leakage Research Articles

Impact of convex ostomy appliances on leakage frequency, peristomal skin health and stomal protrusion

Aim: The Convexity in Ostomy (ECOS) study measured the impact of soft convex ostomy appliances on leakage frequency, peristomal skin health, and patient satisfaction, as well as stomal protrusion and body profile. Methods: This prospective non-randomised controlled trial included people with a stoma, divided into a control group using a convex appliance throughout (Alterna Confort Convex or Easiflex Confort Convex Light, Coloplast A/S, Humlebæk, Denmark), and an intervention group who were using a flat appliance at baseline before switching to a convex appliance for the rest of the study. Leakage frequency was counted within the past 2 weeks; peristomal skin health was assessed using the discolouration, erosion and tissue overgrowth (DET) Ostomy Skin Tool; and patient satisfaction was measured with a 0-10 Likert scale of self-reported satisfaction with the appliance. Measurements were taken at three visits: baseline (V1), 2-8 weeks (V2) and 6 months (V3). The Kruskal-Wallis and analysis of variance (ANOVA) tests were used for comparison. Multiple regression analysis was used to evaluate the effect of independent variables on the change in leakage frequency and DET score between baseline and 6 months. Findings: Of 253 participants screened, 245 completed the follow-up, with 151 in the intervention group and 94 in the control group. Mean leakage frequency period went from 5.85 ± 5.55 (V1) to 0.63 ± 1.42 (V2) and 0.23 ± 0.75 (V3) (p<.0001). Mean DET score changed from 4.8 ± 3.47 (V1) to 1.41 ± 2.17 (V2) and 0.54 ± 1.57 (V3) (p<.0001). Mean satisfaction changed from 6.0 ± 2.25 (V1) to 8.6 ± 1.14 (V2) and 9.17 ± 0.93 (V3) (p<.0001). From V1 to V3, the proportion of patients with a depressed peristomal area went from 45.7% to 31.4%, a normal peristomal area went from 45.3% to 65.3%, stoma protrusion went from 31.4% to 47.3% and stoma retraction went from 28.6% to 15.5%. By group, mean leakage frequency decreased in the intervention group by 7.65, from 7.57 to 0.11, and in the control group by 2.37, from 2.94 to 0.46 (p<0.0001). Multiple ANOVA analysis confirmed independent variables in reducing leakage to be initiating convexity and appliance coupling. By group, mean DET score decreased in the intervention group by 4.82, from 5.24 to 0.42, and in the control group by 3.52, from 4.34 to 0.76. Multiple ANOVA analysis showed independent variables for DET score to be initiating convexity, emergency surgery and stoma siting. Conclusion: People with a stoma experiencing repeated leakage benefitted from shifting from a flat to a soft convex appliance in terms of leakage frequency, peristomal skin health, stomal protrusion and body profile.

Comparison of the Ability of Two Brands of CBCT with That of SEM to Detect the Marginal Leakage of Class V Composite Resin Restorations.

Objectives This study was carried out to compare the ability of two common brands of cone-beam computed tomography (CBCT), including New Tom and Planmeca, to detect the marginal leakage of class V composite resins. The ability of each of the two brands of CBCT to detect the marginal leakage of class V composite resins was also compared with that of scanning electron microscopy (SEM). Methods Class V cavities were prepared on the buccal surface of sixteen extracted caries-free human premolars. Cavities were conditioned and filled with composite resin. The teeth were immersed in 50% weight/weight aqueous silver nitrate solution for 24 hours. They were then taken out and rinsed with distilled water. Next, they were put in a developing solution. They were first viewed with New Tom and Planmeca CBCT units and were then sectioned and evaluated by an SEM. Results The results of the Wilcoxon signed-rank test showed no significant difference between the mean marginal leakage scores of New Tom and Planmeca CBCT images (p value = 0.157) and between those of New Tom CBCT and SEM images (p value = 0.098). However, there was a significant difference between the mean marginal leakage scores of Planmeca CBCT and SEM images (p value = 0.023). Conclusion There were no significant differences between New Tom and Planmeca CBCT units in the detection of marginal leakage of class V composite resins. However, when these CBCT units were compared with the SEM, the New Tom CBCT unit could detect the marginal leakage better than Planmeca.

An ex vivo evaluation of two different suture techniques for the Ozaki aortic neocuspidization procedure.

We investigated the Ozaki procedure using a single interrupted suture technique (SST) and compared this with the standard continuous suture technique (CST) with regard to hydrodynamic valve performance. In addition, both techniques were compared with the native aortic valve (NAV). Effective orifice area, mean pressure gradient and leakage volume were evaluated in the NAV as well as after an Ozaki procedure using SST or CST in fresh swine aortic roots using a mock circulation loop. The NAV, SST and CST were evaluated under 4 defined hydrodynamic conditions. Both suture techniques resulted in a similar effective orifice area under all conditions [for stroke volume of 70 ml: SST: 1.50 (1.35-1.87) vs CST: 1.57 (1.41-1.72) cm2, P = 0.8] and there were no significant differences between both suture techniques and the NAV (P > 0.05). Regarding mean pressure gradient, the Ozaki procedure with SST and CST showed no significant differences [7.23 (5.53-8.91) vs 7.04 (6.65-7.60) mmHg, P = 0.72] and there was no significant difference between both suture techniques and the NAV (P > 0.1). In leakage volume, there was no significant difference between SST and CST [4.49 (3.91-4.99) vs CST: 4.23 (3.58-4.87) ml/stroke, P = 0.34]. The Ozaki procedure with SST performed similarly to that with CST with regard to hydrodynamic performance. Our results suggest that the Ozaki procedure can be performed with SST instead of CST, which may be useful in patients with limited surgical exposure, such as a small annulus.

Long-term multimodal imaging characterization of persistent retinal neovascularization using DL-alpha-aminoadipic acid in pigmented and white rabbits

PurposeIntravitreal (IVT) injection of DL-alpha-aminoadipic acid (AAA) is a new animal model for retinal neovascularization (RNV) reported in rabbits. This study performs longitudinal multimodal imaging for up to 1 year to evaluate DL-AAA RNV in both New Zealand white (NZW) rabbits and Dutch-Belted pigmented (DBP) rabbits. MethodDetailed characterization and quantification of this model were performed in these two strains in 32 eyes by optical coherence tomography (OCT), fundus photography, and fluorescein angiography (FA) for up to 16 weeks following DL-AAA administration in 32 eyes and up to 52 weeks in 5 eyes. H & E histology was also performed in these two strains 8 weeks after injection of DL-AAA. ResultRNV was successfully generated using 50 μL 80 mM DL-AAA solution for DBP rabbits and 80 μL 80 mM DL-AAA for NZW rabbits. The incidence of persistent vascular leakage is 100% (15/15) for DBP rabbits and 70.6% (12/17) for NZW rabbits at 16 weeks. Complications with NZW rabbits ultimately decreased the efficiency in NZW rabbits to 58.8% (10/17) of NZW rabbits getting persistent (to 16 weeks) vascular leakage without ocular complications as compared with 100% (15/15) in DBP rabbits. Five eyes (2 DBP and 3 NZW) were selected from those demonstrating RNV at 16 weeks and were monitored for up to 52 weeks. All 5 demonstrated persistent RNV to 52 weeks. Quantification of the mean leakage area (MLA) in DBP rabbits is more accurate than in NZW rabbits since the reduced contrast between the leakage and background in NZW rabbits makes it more challenging to quantify. ConclusionDL-AAA can induce persistent and quantifiable RNV in both DBP and NZW rabbits. DBP rabbits have a higher success rate, lower required volume of DL-AAA, and more accurate method for quantification that could be more desirable.

Sealing Ability of Mineral Trioxide Aggregate, Biodentine and Glass Ionomer as Root-End Materials: A Question of Choice.

The goal of this study was to determine the sealing ability of MTA, Biodentine, and Fuji IX as root-end materials after ultrasonic retrograde preparation using a dye penetration method. Seventy permanent anterior teeth were used in this study. Root canals were prepared using rotary endodontic files, and obturated using the lateral condensation technique. The resection of the root apices was performed perpendicularly to the long axis, and 3 mm deep retrocavities were made by ultrasonic tips. The samples were randomly divided into three experimental groups (N=20) and two control groups (N=5). The root-end cavities were filled with mineral-trioxide aggregate (Rootdent MTA, TehnoDent, Russia) in Group 1, Biodentine (Septodont, Saint Maur des Fossés, France) in Group 2 and Fuji IX GP (GC Corporation, Tokyo, Japan) in Group 3. The retrocavities of the positive control group were left unfilled, while retrocavities in the negative control group were sealed using a flowable composite material. The samples were made transparent, and dye penetration was assessed under a stereomicroscope (x10). The data were analyzed with the Kruskal-Wallis test and the Mann-Whitney U-test. The Biodentine group had a lower mean leakage value than the MTA and Fuji IX groups, and the difference was statistically significant (P<0.01). No statistical difference in apical microleakage was found between the MTA and Fuji IX groups (P>0.05). Within the limitations of this study, it was concluded that Biodentine provides better sealing ability as a root-end material than MTA and Fuji IX. There was no statistically significant difference between the sealing ability of MTA and Fuji IX as root-end materials.

Bicuspid aortic valve morphology and aortic valvular outflow jets: an experimental analysis using an MRI-compatible pulsatile flow circulation system

The characteristics of aortic valvular outflow jet affect aortopathy in the bicuspid aortic valve (BAV). This study aimed to elucidate the effects of BAV morphology on the aortic valvular outflow jets. Morphotype-specific valve-devising apparatuses were developed to create aortic valve models. A magnetic resonance imaging-compatible pulsatile flow circulation system was developed to quantify the outflow jet. The eccentricity and circulation values of the peak systolic jet were compared among tricuspid aortic valve (TAV), three asymmetric BAVs, and two symmetric BAVs. The results showed mean aortic flow and leakage did not differ among the five BAVs (six samples, each). Asymmetric BAVs demonstrated the eccentric outflow jets directed to the aortic wall facing the smaller leaflets. In the asymmetric BAV with the smaller leaflet facing the right-anterior, left-posterior, and left-anterior quadrants of the aorta, the outflow jets exclusively impinged on the outer curvature of the ascending aorta, proximal arch, and the supra-valvular aortic wall, respectively. Symmetric BAVs demonstrated mildly eccentric outflow jets that did not impinge on the aortic wall. The circulation values at peak systole increased in asymmetric BAVs. The bicuspid symmetry and the position of smaller leaflet were determinant factors of the characteristics of aortic valvular outflow jet.

Characteristics of Toxic Gas Leakages with Change in Duration

One of the emergencies rescue crews have to face is toxic gas leakages. The characteristics of the gas leakages differ with regard to their leakage duration. Long-term releases have plume-like behaviors that can be described by utilizing mean concentrations at individual exposed locations. In contrast, ensemble statistics of individual cloud characteristics are needed for short-term releases with puff-like behaviors to ensure fully aware risk assessment. The reason is that the time evolution of the concentration of short-term gas releases can differ wildly under the same mean ambient and leakage conditions. The duration from which the release can be classified as plume-like can be found only by studying the releases of different durations, which is the main aim of this paper. To investigate gas releases of different durations, wind tunnel experiments of gas releases in an idealized urban area were conducted. The results present a new method by which concentration signals of releases can be divided into three cloud phases: the arrival, the central and the departure cloud phase. The characteristics (e.g., lengths, mean concentrations) of the individual cloud phases are explored. The results indicate that the finite-duration releases for which the central cloud phase exists have the plume-like behavior for this cloud part.

Integrating CVH and LVH metrics into an optimization strategy for the selection of Iris collimator for Cyberknife Xsight lung tracking treatment.

PurposeWe conducted this study to construct a target coverage‐volume histogram (CVH) and leakage‐volume histogram (LVH) metrics and optimization strategy for the selection of the Iris collimator in Cyberknife Xsight lung tracking treatment through a retrospective analysis of target structures and clinical data.Methods and MaterialsCVH and LVH metrics were retrospectively analyzed for 37 lung cancer patients. CVH and LVH were the same as dose‐volume histogram (DVH), but with a coverage and leakage replacing dose. For each patient, Iris collimator was optimized and selected based on CVH and LVH metrics. The CVH and LVH metrics were then compared to ascertain differences in 95% (C95) or 90% (C90) of the target coverage thresholds. The planning target volume (PTV) C95 and C90 coverage, absolute mean leakage value, leakage/coverage ratio, selected collimator diameter (Φ), Φ/length of the long axis of PTV (Amax), and Φ/length of the short axis (Amin) of PTV were compared. The correlation of the absolute mean leakage value, leakage/coverage ratio, Φ/Amin and Φ/Amax were evaluated.ResultsFor each patient, the PTV C95 coverage (70.45 vs 63.19) and C90 coverage (77.25 vs 69.96) were higher in the C95 coverage threshold group compared to the C90 coverage threshold group. The leakage/coverage ratio (0.56 vs 0.69) and absolute mean leakage value (0.56 vs 0.61) were lower in C90 coverage threshold group than in C95 coverage threshold group. The Spearmen correlation test showed the Φ/Amin were significantly correlated with leakage/coverage ratio and absolute mean leakage value. Upon analysis of the selected collimator diameters, the mean value of Φ/Amin of the optimized collimator diameters was found to be 1.10.ConclusionThe CVH and LVH analysis is able to quantitatively evaluate the tradeoff between target coverage and normal tissue sparing.

In vitro holding security of four friction knots of monofilament or multifilament suture used as a first throw for vascular ligation.

To evaluate holding security of 4 friction knots created with various monofilament and multifilament sutures in a vascular ligation model. 280 friction knot constructs. 10 friction knots of 4 types (surgeon's throw, Miller knot, Ashley modification of the Miller knot, and strangle knot) created with 2-0 monofilament (polyglyconate, polydioxanone, poliglecaprone-25, and glycomer-631) and braided multifilament (silk, lactomer, and polyglactin-910) sutures were separately tied on a mock pedicle and pressure tested to the point of leakage. Linear regression analysis was performed to compare leakage pressures among suture materials (within friction knot type) and among knot types (within suture material). Mean leakage pressure of surgeon's throws was significantly lower than that of all other knots tested, regardless of the suture material used. All the other knots had mean leakage pressures considered supraphysiological. Significant differences in mean leakage pressure were detected between various friction knots tied with the same type of suture and various suture types used to create a given knot. Variability in leakage pressure among knots other than the surgeon's throw was greatest for poliglecaprone-25 and lowest for polydioxanone. Most differences in knot security, although statistically significant, may not have been clinically relevant. However, results of these in vitro tests suggested the surgeon's throw should be avoided as a first throw for pedicle ligation and that poliglecaprone-25 may be more prone to friction knot slippage than the other suture materials evaluated.

Sealing Ability of AH Plus and GuttaFlow Bioseal.

The objective of root canal obturation is to achieve a fluid-tight seal. Recently, GuttaFlow bioseal (GB), a root canal sealer composed of polydimethylsiloxane, gutta-percha particles, and bioactive glass ceramics, has been developed, to enhance the sealing ability of root canal filling material. The objective of this study was to assess the sealing ability of GB using a subnanoliter-scaled fluid-flow measuring device and to compare with that of AH Plus (AH). The fluid flow in root canal-filled teeth using either gutta-percha cone (GP) with AH (GAR; n = 10) or GP with GB (GBR; n = 10) and in GP inserted in AH blocks (GA; n = 10) or GP inserted in GB blocks (GB; n = 10) was measured. In addition, fluid flow in sealer blocks of AH (A; n = 10) and GB (B; n = 10), which served as negative controls, was measured. Root canal-filled teeth using GP without any sealer (GR) acted as positive controls (n = 10). The leakage was obtained by calculating the volume of moved water by time (s), after stabilization of the fluid flow was achieved. Statistical analysis was performed using the Kruskal–Wallis test and Mann–Whitney U-test with Bonferroni correction. A p value less than 0.00238 (0.05/21) was considered significantly different. The mean leakages (nL/s) in the groups are as follows: GAR, 0.0958 ± 0.0543; GBR, 0.0223 ± 0.0246; GA, 0.0644 ± 0.0803; GB, 0.0267 ± 0.0182; A, 0.0055 ± 0.0057; B, 0.0052 ± 0.005; and GR, 0.2892 ± 0.3018. The mean leakage in the GBR group was lower than that in the GAR group (p = 0.001), while the mean leakages in the GA and GB groups were not significantly different. GuttaFlow bioseal can be useful in single-cone obturation technique.

Comparative evaluation of the effect of artificial aging on the marginal leakage of cast crowns luted with three cements: An in vitro study

Aims and Objectives: This study was carried out to evaluate the effect of artificial aging on the marginal leakage of crowns and the credibility of three different luting cements in preventing marginal percolation. Materials and Methods: Thirty-six extracted intact premolars were selected for the study. Tooth preparation was carried out to receive complete cast crown. Castings were microblasted with 50 μm alumina powder. Group I was cemented with zinc polycarboxylate (Poly-F® Dentsply De Trey GmbH, Konstanz, Germany), Group II with glass ionomer (Fuji I, Fuji I GC Corporation, Tokyo, Japan), and Group III with resin-modified glass ionomer (Fuji II Plus, Fuji II Plus GC Corporation, Tokyo, Japan). The specimens in the subgroup I served as the control group and those in the subgroup II were subjected to thermocycling to simulate the intraoral conditions. They were artificially aged using artificial saliva as a medium of thermocycling, with a temperature variation of 5°C–55°C. All specimens were treated with 0.5% basic fuchsin dye for 24h. The crowns were then embedded in clear self-cure acrylic resin and sliced buccolingually. The sectioned halves were then placed under the optical vision microscope, and the depth of dye penetration in the proximal region was qualitatively evaluated. Results: The results showed the mean marginal leakage score is highly significant in thermocycled group as compared to that in non-thermocycled group. The results were subjected to one-way analysis of variance and post hoc Tukey test. It was found that artificial aging did have an effect on the marginal leakage of zinc polycarboxylate group and glass ionomer group. The resin-modified glass ionomer group, however, did not show much significant difference. Conclusion: The artificial aging did have an effect on the marginal leakage of polycarboxylate group and glass ionomer group, whereas resin-modified glass ionomer group did not show much statistical significance. Zinc polycarboxylate cement had maximum micro-leakage followed by glass ionomer cement. Resin-modified glass ionomer showed minimum leakage and can be regarded as the best cement for clinical use.

Bacterial Leakage of Four Endodontic Sealers Using Fresh Human Saliva.

Bacterial leakage plays a considerable role in endodontic related failures. The aim of this study was to compare the bacterial leakage of bioceramic (including Well Root ST and MTA Fillapex) and resin-based root canal sealers (naming AH-Plus and AdSeal). Sixty-eight maxillary central incisors were included in this experimental study. These were randomly allocated into four experimental groups, which were obturated with gutta-percha and four different sealers (n=15), and the two control groups (positive, n=4 and negative, n=4). A dual-chamber technique was carried out using fresh human saliva and traced for 90 days. The Chi-square and Long Rank tests were performed for data analysis. Bacterial leakage was observed in 33.3% of the samples in Well Root ST, 40% in AH-Plus group, 53.3% in AdSeal group, and 66.6% in MTA Fillapex group. The difference between the Well Root ST and MTA Fillapex groups was significant (P=0.02). The mean leakage time between the Well Root ST (85.6 days) and MTA Fillapex groups (71.2 days) was also significant (P=0.037). The results of this in vitro study revealed bacterial leakage in all experimental groups. The Well Root ST and the MTA Fillapex groups showed the lowest and highest bacterial leakages, respectively. Then it seems that the Well Root ST is a good substitute for MTA Fillapex in clinical applications.

Numerical analysis of the groove effect on the tip leakage vortex cavitating flow

In this paper, the groove effect on the tip leakage vortex cavitating flow characteristics of a simplified NACA0009 hydrofoil with tip gap is studied. Considering local rotation characteristics and curvature effects of the tip leakage vortex flow, the rotation-curvature corrected shear-stress-transport turbulence model is applied to simulate the time-averaged turbulent flow. The Zwart–Gerber–Belamri cavitation model is used to simulate the cavitating flow. The results show that the groove could affect the tip leakage vortex cavitating flow. The groove enhances the interaction between the tip leakage flow and main flow, and then it affects the cavitation of the tip leakage vortex. Compared with the non-groove case, for groove cases of αgre ≤75°, the tip leakage vortex cavitating flow is suppressed, the flow pattern in the gap is improved, and the mean leakage velocity Vlk &lt; 0.8. The region of high leakage velocity is eliminated and the distribution of the pressure is more uniform. The tip leakage vortex cavitation area is reduced, and the maximum decrease is 72.90%. While for groove cases of αgre≥90°, neither the tip leakage vortex cavitating flow nor flow pattern in the tip gap is ameliorated, the mean leakage velocity Vlk lies the range from 0.90 to 0.96. The region of high leakage velocity still exists and even the tip leakage vortex cavitation area is increased. Based on three-dimensional streamlines and vorticity transport equation, the interaction between the tip leakage flow and main flow leads to the variation of the tip leakage vortex cavitating flow. This paper aims for a useful reference to mitigate the tip leakage vortex cavitation and control the influence of the tip leakage vortex cavitating flow for the hydraulic machinery.

Influence of leaflet geometry on hydrodynamic performance of transcatheter aortic valve prostheses

Abstract The implantation of transcatheter aortic valve prostheses (TAVP) for therapy of aortic valve stenosis shows more and more clinically non-inferiority results compared to surgical valve replacement in intermediate and low risk patients. Commonly clinically used TAVP are manufactured from chemically fixed xenograft leaflet material, e.g. bovine or porcine pericardium. While the clinical use of TAVP currently extends, challenges concerning valve durability and leaflet calcification have to be addressed. In this regard, artificial leaflet materials represent a promising option for a next generation of TAVP. As a first step for the development of TAVP from polymeric nonwoven, the aim of this study was to determine the influence of leaflet geometry on hydrodynamic performance of TAVP prototypes. Based on a parametric model of the valve leaflets, we varied the curvature of the belly line forming the leaflet coaptation area from an initial, quite concave, leaflet geometry with a value of 0.5° to an almost straight geometry for the leaflets with a value 0.15°. Manufacturing of TAVP prototypes was conducted by means of electrospinning technique with a polycarbonate based silicone elastomer. Hydrodynamic characterization according to ISO 5840-3 standards was performed using a pulse duplicator system with a heart rate of 70 BPM, systolic duration of 35%, mean aortic pressure of 100 mmHg and a stroke volume of 96 ml. Cardiac output as well as mean transaortic pressure gradient, closing volume, leakage volume and regurgitation were measured to compare the different leaflet geometries. To summarize, the curvature of the leaflets’ belly has a crucial impact on TAVP hydrodynamics under physiological test conditions. In particular, the opening and closing behavior is strongly influenced by a steeper curvature leading to larger closing volumes and higher regurgitant fractions. Further studies are planned to identify an optimum with respect to leaflet material selection, leaflet geometry and hydrodynamic properties of TAVP.

Surface Evaporation in Arid Regions: Insights From Lysimeter Decadal Record and Global Application of a Surface Evaporation Capacitor (SEC) Model

AbstractSurface evaporation in arid regions determines the fraction of rainfall that remains to support vegetation and recharge. The surface evaporation capacitor approach was used to estimate rainfall partitioning to surface evaporation and leakage into deeper layers. The surface evaporation capacitor estimates a soil‐specific surface evaporation depth and critical storage capacitance that defines rainfall events that exceed local capacitance and result in leakage into deeper layers protected from surface evaporation. A decade‐long record of hydrologic observations in deep and barren lysimeters near Las Vegas revealed the dominance of a few large rainfall events in generating leakage and increasing interannual soil water storage. The surface evaporation capacitor was used to estimate mean annual surface evaporation and leakage protected from surface evaporation in all arid regions globally. About 13% of arid region rainfall contributes to soil water storage (in the absence of vegetation), similar to 11% found in the lysimeter study.

The influence of palatal harvesting technique on the donor site vascular injury: A split-mouth comparative cadaver study.

The aim of this study was to evaluate the influence of two harvesting approaches on the donor site vascular injury. A split-mouth cadaver study was designed on 21 fresh donor heads. Every hemi-palate was assigned to receive the trap-door harvesting technique (TDT) or the epithelialized free gingival graft harvesting technique (FGGT). A soft tissue graft was harvested from each side for histology analyses. Betadine solution was used to inject the external carotid artery and a collagen sponge was positioned over the harvested area to compare the amount of "leakage." The mean leakage observed was 16.56±3.01 µL in the FGGT-harvested sites, and 69.21±7.08 µL for the TDT group, a ratio of 4.18 (P<0.01). Regression analyses demonstrated a trend for more leakage at thinner palatal sites for the FGGT group (P=0.09), and a statistically significant correlation for the TDT-harvest sites (P=0.02). Additionally, a shallow palatal vault height (PVH) was associated with a higher leakage in both harvesting groups (P=0.02). The histomorphometric analyses revealed that grafts harvested with TDT exhibited a significantly higher mean number of medium (ø=0.1 to 0.5mm, P=0.03), and large vessels (ø ≥ 0.5mm, P=0.02). Within the limitations of the present research, the TDT resulted in a significantly higher leakage than the FGGT, which was also correlated with the histology analyses where a greater number of medium and large vessels were observed in the harvested grafts.

Critical investigation of glove–gown interface barrier performance in simulated surgical settings

The barrier properties of personal protective equipment are vital to healthcare personnel to protect themselves from possible infectious body fluids. Intraoperative exposure of healthcare personnel to body fluids can be substantial in both inpatient and outpatient settings. The glove–gown interface is known as one of the weakest points of the whole personal protective equipment system. However, there is a lack of scientific research designed to investigate the problem. This paper reports the results of experiments using a new testing methodology developed to quantify fluid leakage through the glove–gown interface while simulating surgical settings in terms of operating room personnel activities, exposure types, exposure durations, and physical stresses applied on the interface. This study represents one of the first efforts investigating the amount of fluid leakage through the glove–gown interface for a number of surgical gown and glove models while considering glove material differences and single vs. double gloving. The test results showed that there is a significant difference in fluid leakage amounts between three gown models and four glove models studied. The results also demonstrated that double gloving significantly reduced the fluid leakage compared to single glove use. The mean fluid leakage was lower in the double synthetic glove configurations (M = 2.76g) compared with all other configurations (3GLV, M = 8.3g; 4GLV, M = 9.49g; 5GLV, M = 3.08g; 6GLV, M = 20.03g; double latex, M = 5.22g). Findings highlighted a significant interaction between glove and gown designs, which suggests that gown and gloves should be designed together as a system to minimize or eliminate the fluid leakage.

Ex vivo evaluation of the distribution of a mixture of mepivacaine 2% and iopromide following local infiltration of the infraorbital nerve via the infraorbital foramen

SummaryThe objective of this study was to investigate the distribution pattern of two different volumes of a mepivacaine 2%/iopromide mixture along the infraorbital nerve using a controlled injection pressure. Infraorbital nerve blocks were performed at the infraorbital foramen with two different volumes (group 10: 10 mL or group 15: 15 mL) using a 22 gauge, 3 cm long needle and a standardised injection pressure in 10 cadaver skulls. Ten minutes after injection, computed tomography was performed in all skulls. Images were analysed for needle position, length of the iopromide column, filling percentage of the infraorbital canal, presence of iopromide at the maxillary foramen, volume of leakage, length and angle of the infraorbital canal and pathological changes. Percentage of infraorbital canal filling ranged from 74% ± 0.23 to 86.9% ± 0.24 and iopromide was present at the maxillary foramen in 70–90% of the blocks of groups 15 and 10 respectively; neither variables differed significantly between groups 15 and 10 (P = 0.582 and P = 0.244 respectively). Mean leakage retrograde into the rostrally surrounding tissue and into the maxillary sinus was significantly greater in group 15 (7.9 cm3 ± 4.2) than group 10 (3.02 cm3 ± 3.13), P = 0.008. Older horses were significantly associated with higher filling percentages (P = 0.049), whereas filling percentages or whether the mixture reached the maxillary foramen were not associated with any of the other variables. Infraorbital nerve blocks using 10 and 15 mL result in complete filling of the infraorbital canal in the majority of horses. This block may result in sufficient analgesia of Triadans 06 to 11 and offer a suitable safe alternative to maxillary nerve blocks.

3361 Feasibility, Acceptability, and Appropriateness of an Insertable Vaginal Cup to Manage Urinary Incontinence Among Women with Obstetric Fistula in Ghana: A Mixed Methods Study

OBJECTIVES/SPECIFIC AIMS: 1. To assess feasibility (efficacy, safety, acceptability) of the menstrual cup for managing urinary incontinence among women with obstetric fistula 2. To examine pre-implementation facilitators and barriers (including appropriateness) among additional stakeholders METHODS/STUDY POPULATION: Sequential explanatory mixed methods study whereby repeated measures clinical trial results are explained by subsequent interviews with additional women with OF on coping and stigma and other stakeholders on perceptions of fistula self-management. RESULTS/ANTICIPATED RESULTS: Of the 32 patients screened, 11 were eligible (100% consent rate). At baseline, mean (±SD) leakage in ml was 63.2 (±49.2) (95% CI: 30.2-96.3) over two hours, while the mean leakage over two hours of use of the cup was 16.8 (±16.5) (95% CI: 5.7-27.9). The mean difference of 46.4 (±52.1) ml with use of the cup (95% CI: 11.4-81.4) was statistically significant (p = 0.02). With the cup, women experienced an average 61.0% (±37.4) (95% CI: 35.9-86.2) leakage reduction, a difference 10/11 users (91.0%) perceived in reduced leakage. One participant, reporting four previous surgical attempts, experienced a 78.7% leakage reduction. Acceptability was high–women could easily insert (8/11), remove (8/11), and comfortably wear (11/11) the cup and most (10/11) would recommend it. No adverse effects attributable to the intervention were observed on exam, although some women perceived difficulties with insertion and removal. Data collection tools were appropriate with slight modification advised. Interviews highlighted that women were already using various active coping and resistance strategies but lacked access to tools to support coping. Additional stakeholders reported the innovation was a simple, low-cost device that is an appropriate fit with ongoing fistula programming. Pre-implementation facilitators include the clear relative advantage to existing self-management strategies, the potential to build upon existing partnerships to implement, and a tension for change to address surgical gaps. Barriers included additional stakeholder’s perceptions of low user acceptability and appropriateness in some cases and the need for additional study data to inform decision making for practice and policy. DISCUSSION/SIGNIFICANCE OF IMPACT: The innovation is efficacious, acceptable, adds to current coping strategies, and fits within existing fistula programs. Stakeholders’ pre-implementation perceptions highlight the importance of partnerships and the need for an evidence base related to effectiveness, acceptability, and cost. Challenges to address include access to resources within these contexts (water, soap, and safe space to empty cup) and development of a culturally appropriate counseling message. Future research warranted.

Numerical and in-vitro experimental assessment of the performance of a novel designed expanded-polytetrafluoroethylene stentless bi-leaflet valve for aortic valve replacement.

The expanded polytetrafluoroethylene (ePTFE) heart valve can serve as a viable option for prosthetic aortic valve. In this study, an ePTFE bi-leaflet valve design for aortic valve replacement (AVR) is presented, and the performance of the proposed valve was assessed numerically and experimentally. The valve was designed using CAE software. The dynamic behavior of the newly designed bi-leaflet valve under time-varying physiological pressure loading was first investigated by using commercial finite element code. Then, in-vitro tests were performed to validate the simulation and to assess the hemodynamic performance of the proposed design. A tri-leaflet ePTFE valve was tested in-vitro under the same conditions as a reference. The maximum leaflet coaptation area of the bi-leaflet valve during diastole was 216.3 mm2. When fully closed, no leakage gap was observed and the free edges of the molded valve formed S-shaped lines. The maximum Von Mises stress during a full cardiac cycle was 4.20 MPa. The dynamic performance of the bi-leaflet valve was validated by the in-vitro test under physiological aortic pressure pulse. The effective orifice area (EOA), mean pressure gradient, regurgitant volume, leakage volume and energy loss of the proposed valve were 3.14 cm2, 8.74 mmHg, 5.93 ml/beat, 1.55 ml/beat and 98.99 mJ, respectively. This study reports a novel bi-leaflet valve design for AVR. The performance of the proposed valve was numerically and experimentally assessed. Compared with the reference valve, the proposed design exhibited better structural and hemodynamic performances, which improved valve competency. Moreover, the performance of the bi-leaflet design is comparable to commercialized valves available on the market. The results of the present study provide a viable option for the future clinical applications.