Treating Femoral Artery Pseudoaneurysm by Tumescence Anesthesia and Echo-Guided Compression Technique (TACT): Clinical Outcome in 82 Consecutive Patients

PURPOSE

Pseudoaneurysm (PA) of the access artery is a common and potentially severe complication after percutaneous endovascular interventions. Most PA require interventional therapy, including thrombin injection, covered stent implantation, or surgical repair, which are costly and associated with other complications. Treating PA by external compression is uncomfortable and time consuming, with a low success rate. By injecting local tumescence anesthesia around the PA and close to its neck, the tumescence anesthesia and echo-guided compression technique (TACT) aims to improve efficacy and patient's comfort.

MATERIALS AND METHODS

We retrospectively reviewed all consecutive patients treated for femoral PA in our center from May 2009 to July 2019 and estimated efficacy and safety. Vascular specialists performed TACT according to a standardized protocol including ultrasound-guided injection of tumescence solution (45 ml of 0.9% saline, 15 ml of lidocaine 1%/epinephrine 5 μg/ml) in the soft tissue around the PA and its neck, local compression with the sonography probe until PA closure, and external compression by elastic belt for 3 hours.

RESULTS

Among a total of 125 patients with femoral artery PA, 82 (65.6%) were treated by TACT (including 3 patients with haemorrhagic shock), 14 (11.2%) by thrombin injection; 12 (9.6%) by endovascular interventions; 8 (6.4%) by open surgery; and 9 (7.2%) conservatively. In patients treated by TACT, PA neck was short (<1 cm) in 51.8% and mean cavity diameter 30 ± 23 mm. After injection of 58 ± 8 ml of tumescence solution, mean time of echo-guided compression was 12 ± 8 minutes. Pseudoaneurysm was successfully closed in 92.7% after the first attempt and in 96.3% after the second attempt. The intervention was well tolerated, without any adverse event.

CONCLUSION

Tumescence anesthesia and echo-guided compression technique (TACT) is an effective and safe treatment for PA. Compared to other therapies, TACT is minimally invasive and widely available for minimal costs, even for large PA and in unstable patients.

CLINICAL IMPACT

Tumescence anesthesia and echo-guided compression technique seems to be an efficient, safe, and a fair economical choice in comparison with alternative techniques. The implementation of this procedure is simple with low risk of complications. Based on the results of this study, we believe that TACT should be considered as the first-line treatment of most iatrogenic PA.

Leukocyte- and platelet-rich fibrin in cranial surgery: a single-blinded, prospective, randomized controlled noninferiority trial

OBJECTIVE

CSF leakage is a major complication after cranial surgery, and although fibrin sealants are widely used for reinforcing dural closure, concerns exist regarding their safety, efficacy, and cost. Leukocyte- and platelet-rich fibrin (L-PRF), an autologous platelet concentrate, is readily available and inexpensive, making it a cost-effective alternative for commercially available fibrin sealants. This study aimed to demonstrate the noninferiority of L-PRF compared with commercially available fibrin sealants in preventing postoperative CSF leakage in supra- and infratentorial cranial surgery, with secondary outcomes focused on CSF leakage risk factors and adverse events.

METHODS

In a single-blinded, prospective, randomized controlled interventional trial conducted at a neurosurgery department of a tertiary care center (UZ Leuven, Belgium), patients undergoing elective cranial neurosurgery were randomly assigned to receive either L-PRF (active treatment) or commercially available fibrin sealants (control) for dural closure in a 1:1 ratio.

RESULTS

Among 350 included patients, 328 were analyzed for the primary endpoint (44.5% male, mean age 52.3 ± 15.1 years). Six patients (5 in the control group, 1 in the L-PRF group) presented with CSF leakage requiring any intervention (relative risk [RR] 0.20, one-sided 95% CI -∞ to 1.02, p = 0.11), confirming noninferiority. Of these 6 patients, 1 (in the control group) presented with CSF leakage requiring revision surgery. No risk factors for reconstruction failure in combination with L-PRF were identified. RRs for adverse events such as infection (0.72, 95% CI -∞ to 1.96) and meningitis (0.36, 95% CI -∞ to 1.25) favored L-PRF treatment, although L-PRF treatment showed slightly more bleeding events (1.44, 95% CI -∞ to 4.66).

CONCLUSIONS

Dural reinforcement with L-PRF proved noninferior to commercially available fibrin sealants, with no safety issues. Introducing L-PRF to standard clinical practice could result in important cost savings due to accessibility and lower cost. Clinical trial registration no.: NCT03812120 (ClinicalTrials.gov).

Comparison of quartz and sapphire optical chambers for infrared laser sealing of vascular tissues using a reciprocating, side-firing optical fiber: Simulations and experiments

INTRODUCTION

Infrared (IR) lasers are being tested as an alternative to radiofrequency (RF) and ultrasonic (US) surgical devices for hemostatic sealing of vascular tissues. In previous studies, a side-firing optical fiber with elliptical IR beam output was reciprocated, producing a linear IR laser beam pattern for uniform sealing of blood vessels. Technical challenges include limited field-of-view of vessel position within the metallic device jaws, and matching fiber scan length to variable vessel sizes. A transparent jaw may improve visibility and enable custom treatment.

METHODS

Quartz and sapphire square optical chambers (2.7 × 2.7 × 25 [mm3 ] outer dimensions) were tested, capable of fitting into a 5-mm-OD laparoscopic device. A 1470 nm laser was used for optical transmission studies. Razor blade scans and an IR beam profiler acquired fiber (550-µm-core/0.22NA) output beam profiles. Thermocouples recorded peak temperatures and cooling times on internal and external chamber surfaces. Optical fibers with angle polished distal tips delivered 94% of light at a 90° angle. Porcine renal arteries with diameters of 3.4 ± 0.7 mm (n = 13) for quartz and 3.2 ± 0.7 mm (n = 14) for sapphire chambers (p > 0.05), were sealed using 30 W for 5 s.

RESULTS

Reflection losses at material/air interfaces were 3.3% and 7.4% for quartz and sapphire. Peak temperatures on the external chamber surface averaged 74 ± 8°C and 73 ± 10°C (p > 0.05). Times to cool down to 37°C measured 13 ± 4 s and 27 ± 7 s (p < 0.05). Vessel burst pressures (BP) averaged 883 ± 393 mmHg and 412 ± 330 mmHg (p < 0.05). For quartz, 13/13 (100%) vessels were sealed (BP > 360 mmHg), versus 9/14 (64%) for sapphire. Computer simulations for the quartz chamber yielded peak temperatures (78°C) and cooling times (16 s) similar to experiments.

CONCLUSIONS

Quartz is an inexpensive material for use in a laparoscopic device jaw, providing more consistent vessel seals and faster cooling times than sapphire and current RF and US devices.

Prevention of internal bacterial colonization of dental implants: A comparative longitudinal observational study

OBJECTIVES

Previous studies have indicated a progressive internal bacterial colonization of implants and possible implications for peri-implant bone loss. The aim of this study was to evaluate a decontamination protocol, two disinfectants, and a sealant for their ability to prevent such a colonization.

MATERIALS AND METHODS

Bacterial samples were harvested from the peri-implant sulcus (external) and following abutment removal from the implant cavity (internal) during routine supportive peri-implant care in 30 edentulous patients 2 years after they had obtained two implants. In a split-mouth design, implants were randomly assigned to receive either internal decontamination alone (10% H2 O2 , brush) or additional placement of either sealant (GS), disinfectant agent (CHX-varnish) or disinfectant gel (1% CHX-gel), in the internal cavity before remounting of abutment/suprastructure. Twelve months later, internal and external sampling was repeated. Total bacterial counts (TBCs) were determined using real-time PCR in a total of 240 samples (eight per patient).

RESULTS

Total bacterial counts in the internal cavity significantly reduced overall treatment modalities 1 year after the treatments (4.0 [2.3-6.9]-fold reduction; p = .000). No significant differences between the four treatment types were found (p = .348). Comparison of internal and external sampling points revealed significant correlation (R2  = .366; p = .000) with systematically higher TBC counts in external samples.

CONCLUSIONS

Within the limitations of the present study, it can be concluded that the use of disinfectant agents or a sealant did not show an additional benefit in the prevention of internal bacterial colonization of implants compared to a decontamination protocol alone.

The Impact of Proximal Neck Anatomy on the 5-Year Outcomes Following Endovascular Aortic Aneurysm Repair With the Ovation Stent Graft

PURPOSE

Hostile proximal neck anatomy has historically been associated with worse outcomes for endovascular aortic aneurysm repair (EVAR) of abdominal aortic aneurysms (AAA). We investigated the impact of proximal neck anatomy on the outcomes following EVAR with the Ovation abdominal stent graft (Endologix, Irving, Calif).

METHODS

We used prospectively collected data from the Effectiveness of Custom Seal with Ovation: Review of the Evidence database, compromised of pooled data from 6 clinical trials and the European Post-Market Registry of patients undergoing elective infrarenal EVAR (2009-2017). We investigated the impact of short neck length (<10 mm), wide neck diameter (≥28 mm), reverse taper shape (>10%), and neck angulation (>45°) on the outcomes. The primary outcome was type IA endoleak. Secondary outcomes included any type I/III endoleak, sac expansion, aneurysm-related reinterventions, and all-cause and aneurysm-related mortality, and a combined endpoint of type IA endoleak, graft migration, AAA-related reintervention, conversion, and aneurysm rupture. We used Kaplan-Meier analysis and Cox proportional hazards models to estimate the 30 day and 5 year rates and assess univariate and risk-adjusted differences.

RESULTS

Of the 1020 patients, 60 patients had a short neck, 113 had a wide neck diameter, 279 were reverse taper shaped, and 99 had neck angulation >45°. Wide proximal neck was associated with higher 5 year type IA endoleak estimates compared with favorable neck anatomy (7.1% vs 4.3%; p=0.02). No association with 5 year type IA endoleak was found for short neck length (1.7% vs 4.3%; p=0.52), reverse taper shape (3.2% vs 4.3%; p=0.99), or neck angulation (6.1% vs 4.3%; p=0.13). A wide neck diameter compared with favorable anatomy was also associated with higher 5 year estimates of graft migration (3.8% vs 0.4%; p=0.03) and the combined neck-related adverse outcome endpoint (16% vs 9.5%; p=0.002). The estimates of aneurysm sac expansion, rupture, and overall and aneurysm-related mortality were similar between the hostile proximal neck anatomy cohorts and favorable anatomy.

CONCLUSION

Wide proximal neck is associated with higher 5 year type IA endoleak rates for patients treated with the Ovation stent graft. However, short neck length, reverse taper shape, and neck angulation are not associated with higher 5 year type IA endoleak rates.

CLINICAL IMPACT

Hostile proximal neck anatomy has historically been associated with worse outcomes for endovascular aortic aneurysm repair of abdominal aortic aneurysms. The Ovation stent graft platform uses a different proximal sealing method using a polymer inflatable ring, aiming to improve sealing between the graft and aortic wall. This study demonstrated that short, angulated, and reverse taper-shaped neck anatomy did not result in increased type IA endoleak estimates in patients treated with the Ovation stent graft platform. Potentially, the different sealing mechanisms played a role in mitigating the historically worse outcomes in patients with short, angulated, and reverse taper-shaped neck anatomy.

Durability and Additional Properties of Anodized Aluminum-Based Coatings with Different Wettability under Natural Conditions

The study aimed to test the durability of coatings under natural conditions. The present study focused on the changes in wettability and additional properties of the coatings under natural conditions. The specimens were subjected to outdoor exposure and additionally immersed in the pond. Impregnating porous anodized aluminum is a popular production method for hydrophobic and superhydrophobic surfaces. However, prolonged exposure of such coatings to natural conditions causes leaching of the impregnate and, thus, the loss of hydrophobic properties. After the loss of hydrophobic properties, all kinds of impurities and fouling adhere better to the porous structure. Additionally, deterioration of anti-icing and anti-corrosion properties was observed. Finally, the self-cleaning, anti-fouling, anti-icing and anti-corrosion properties were comparable or even worse to those of the hydrophilic coating. In the case of superhydrophobic specimens, during outdoor exposure there was no loss of superhydrophobicity, self-cleaning and anti-corrosion properties. Still, despite this, the icing delay time dropped. During outdoor exposure, the structure, which initially had anti-icing properties, may degrade. Nevertheless, the hierarchical structure responsible for the superhydrophobic effect can still be preserved. The superhydrophobic coating initially had the best anti-fouling properties. However, the coating was also gradually losing its superhydrophobic properties during water immersion.

Sealing of Follicular Openings in Keloid with Cyanoacrylate Glue for Effective Intralesional Therapy

Intralesional therapy is a common treatment for keloid. However, because of some follicular openings and comedones on the surface of the keloid on the hairy chest and acne keloidalis, there is a risk of drug leakage, and sometimes ejection of drugs like a jet spray leads to therapy being ineffective. The authors describe a novel and effective method for preventing drug loss from follicular openings during intralesional therapy. To prevent drug loss during intralesional injection, cyanoacrylate glue is applied to the follicular and comedone openings on the keloid's surface.

Improving the incubation results by sealing the eggshell of cracked hatching eggs with surgical tape

In broiler breeder production, up to 2% of hatching eggs are rejected because of cracked or broken shells. Eggs with cracks give a reduced hatchability and a lower chick quality and cause economic loss. The main goal of this study was to determine the effect of sealing eggshell cracks with surgical tape on hatching parameters. A total of 3,000 eggs from a 34 weeks old Cobb 500 broiler breeder flock was used in the experiment. Six hundred intact eggs represented a positive control. Other eggs were artificially cracked by the operator either on the first day of storage (1,200 eggs) or on the fourth day of storage (1,200 eggs). In both groups, cracks on 600 eggs were sealed by the adhesive surgical tape while the other 600 eggs remained untreated and were used as a negative control. Within each experimental group, eggs were assigned randomly to 4 setter trays representing 4 replicates of 150 eggs. The egg weight loss during incubation was the highest (P < 0.01) in groups of nonsealed cracked eggs. The egg weight loss in sealed groups was higher compared to the control group (P < 0.01). Percentage of egg contamination was not different between groups. Embryonic mortality was higher in non-sealed groups in all stages of embryonic development (P < 0.01) compared to groups of sealed cracked eggs and the control group. Hatching percentage was significantly lower in non-sealed groups (P < 0.01) compared to sealed groups and positive control. No significant difference in hatching parameters was observed between sealed groups and positive control, indicating that surgical tape can be used for sealing cracks on the eggshell to support embryonic survival.

Fluorinated Siloxane Modified Layered Double Hydroxide Sealing Film to Enhance the Corrosion Resistance of Anodic Oxide Film of Fricition Stir Welding Joint of Aluminum Alloys

Aluminum alloys and their welding structures have been widely used in aviation, aerospace, automobiles, ships, and other industrial fields. The non-uniform nature of welding structures of aluminum alloys causes intractable corrosion problems. Anodizing and subsequent sealing processes are common and effective methods to improve the corrosion resistance of welding structures. However, traditional sealing processes like hot water sealing and potassium dichromate sealing are criticized due to energy consumption or toxicity. In this work, a layered double hydroxide (LDH) sealing process with subsequent fluorinated siloxane modification is proposed to improve the corrosion resistance of the anodic oxide film of friction stir welding joints of typical aluminum alloys. The obtained sealing film with typical lamelliform structures of LDH grows well at the defects of oxidation film and also smoothens the sample surface. The hydrophobicity of the film can separate the corrosive medium from the sample surface and further enhance corrosion resistance. As a result, the corrosion current of the welded sample in 3.5 wt.% NaCl solution plummets about 3~4 orders of magnitude compared to the initial state without anodizing, indicating superior corrosion resistance brought by this method.

A straightforward approach for assessing the effectiveness of membrane materials as radon (222Rn) barriers

The ubiquitous presence of the radioisotope radon (²²²Rn) and its short-lived progeny (²¹⁸Po, ²¹⁴Pb, ²¹⁴Bi, ²¹⁴Po) is challenging in two respects: (i) Radon is a major issue regarding health-related problems due to potentially elevated radiation exposure of humans in dwellings, and (ii) due to the mobility of radon the short-lived progeny may cause complications in radionuclide detection in laboratories. Polymer membranes are an appropriate means for effectively preventing unwanted radon migration. However, most of the published literature focusses on robust membranes made for the large-scale sealing of dwelling substructures. Membranes that are suitable (at small-scale) for sealing purposes in radionuclide detection applications are only rarely discussed. In this paper, we present a straightforward practical approach that allows the effectiveness of any membrane to be assessed for any purpose related to radon sealing. Executing the approach requires only (i) a suitable container with inlet and outlet ports, (ii) a mobile radon detector, and (iii) any type of radon source material. The approach provides a tool that allows testing any available membrane for its applicability as radon barrier sheeting.

Laser Structuring and DLC Coating of Elastomers for High Performance Applications

Even though hard, low friction coatings such as diamond like carbon (DLC) would be beneficial for the performance and longevity of rubber seals, a crucial challenge remains. The elastic mismatch of rubber substrate and DLC coating prevents a fracture free coating application. In this work, a nature inspired approach is applied to render the stiff coating flexible and resilient to delamination at the same time by direct patterning. Rubber substrates were laser structured with tile patterns and subsequently DLC coated. Tensile and tribology tests were performed on structured and unstructured samples. Unstructured DLC coatings showed a crack pattern induced by the coating process, which was further fragmented by tensile stress. Coatings with tile patterns did not experience a further fragmentation under load. During continuous tribological loading, less heterogenous damage is produced for tile structured samples. The findings are ascribed to the relief of induced coating stress by the tile structure, meaning a more resilient coating.

Optimization of Titanium Dental Mesh Surfaces for Biological Sealing and Prevention of Bacterial Colonization

Titanium dental meshes have a wide application in order to ensure the retention of calcium phosphate-based biomaterials to regenerate bone tissue. These meshes are temporary and must grow a soft tissue to prevent bacterial colonization and provide stability. In this work, we aimed to optimize the roughness of the meshes to obtain a good biological seal while maintaining a behavior that did not favor bacterial colonization. To this end, six types of surfaces were studied: machined as a control, polished, sandblasted with three different alumina sizes and sintered. The roughness, contact angles and biological behavior of the samples using fibroblast cultures at 7, 24 and 72 h were determined as well as cytotoxicity studies. Cultures of two very common bacterial strains in the oral cavity were also carried out: Streptococcus sanguinis and Lactobacillus salivarius. The results showed that the samples treated with alumina particles by sandblasting at 200 micrometers were the ones that performed best with fibroblasts and also with the number of bacterial colonies in both strains. According to the results, we see in this treatment a candidate for the surface treatment of dental meshes with an excellent performance.

Comparison of fiber-optic linear beam shaping designs for laparoscopic laser sealing of vascular tissues

Infrared lasers may provide faster and more precise sealing of blood vessels and with lower device jaw temperatures than ultrasonic and electrosurgical devices during surgery. Our study explores three beam shaping methods using optical fibers for transformation of a circular laser beam into a linear beam, necessary for integration into a standard 5-mm-diameter laparoscopic device, and for uniform irradiation perpendicular to the vessel length. In the first design, a servo motor connected to a side-firing, 550-μm-core fiber, provided linear translation of a 2.0-mm-diameter circular beam, back, and forth, over either 5 or 11 mm scan lengths for sealing of small or large vessels. The second design used external beam splitters to divide laser power equally into three side-firing fibers, stacked side-by-side, producing a linear beam of 4 × 2 mm. The third design used external beam splitters with three forward-firing fibers and a slanted jaw surface, to produce a linear beam of 5 × 1.5 mm. Laser seals were performed, ex vivo, on 41 porcine renal arteries of 1- to 6-mm diameter (n ≥ 10 samples for each design). Each vessel was compressed to a fixed 0.4-mm-thickness, matching the optical penetration depth at 1470 nm. Vessels were irradiated with fluences of 636 to 800 J/cm², which, based on previous studies, is sufficient for sealing, but not cutting. A burst pressure setup was used to evaluate vessel seal strength. Reciprocating fiber and fiber bundles produced mean burst pressures of 554 ± 142, 524 ± 132, 429 ± 99, and 390 ± 140 mmHg, respectively. All designs consistently sealed blood vessels, with burst pressures above hypertensive (180 mmHg) blood pressures. The reciprocating fiber produced the most uniform linear beam profile and aspect ratio but will require integration of the servo motor into a handpiece. Fiber bundle designs produced shorter, less uniform beams, but enable optical components to be assembled outside the handpiece.

Reciprocating Side-Firing Fiber for Laser Sealing of Blood Vessels

Infrared lasers may provide faster and more precise sealing of blood vessels and with lower jaw temperatures than ultrasonic and electrosurgical devices. This study explores an oscillating or reciprocating side-firing optical fiber method for transformation of a circular laser beam into a linear beam, necessary for integration into a standard 5-mm-diameter laparoscopic device, and for uniform irradiation perpendicular to the vessel length. A servo motor connected to a side-firing, 550-μm-core fiber, provided linear translation of a 2.0-mm-diameter circular beam over either 5 mm or 11 mm scan lengths for sealing small or large vessels, respectively. Laser seals were performed, ex vivo, on a total of 20 porcine renal arteries of 1-6 mm diameter (n = 10 samples for each scan length). Each vessel was compressed to a fixed 0.4-mm-thickness, matching the 1470-nm laser optical penetration depth. Vessels were irradiated with fluences ranging from 636 J/cm² to 716 J/cm². A standard burst pressure (BP) setup was used to evaluate vessel seal strength. The reciprocating fiber produced mean BP of 554 ± 142 and 524 ± 132 mmHg, respectively, and consistently sealing blood vessels, with all BP above hypertensive (180 mmHg) blood pressures. The reciprocating fiber provides a relatively uniform linear beam profile and aspect ratio, but will require integration of servo motor into a handpiece.

The Role of Temperature on the Degree of End-Closing and Filling of Single-Walled Carbon Nanotubes

Carbon nanotubes (CNTs), owing to their high surface area-to-volume ratio and hollow core, can be employed as hosts for adsorbed and/or encapsulated molecules. At high temperatures, the ends of CNTs close spontaneously, which is relevant for several applications, including catalysis, gas storage, and biomedical imaging and therapy. This study highlights the influence of the annealing temperature in the range between 400 and 1100 °C on the structure and morphology of single-walled CNTs. The nitrogen adsorption and density functional theory calculations indicate that the fraction of end-closed CNTs increases with temperature. Raman spectroscopy reveals that the thermal treatment does not alter the tubular structure. Insight is also provided into the efficacy of CNTs filling from the molten phase, depending on the annealing temperature. The CNTs are filled with europium (III) chloride and analyzed by using electron microscopy (scanning electron microscopy and high-resolution transmission electron microscopy) and energy-dispersive X-ray spectroscopy, confirming the presence of filling and closed ends. The filling yield increases with temperature, as determined by thermogravimetric analysis. The obtained results show that the apparent surface area of CNTs, fraction of closed ends, and amount of encapsulated payload can be tailored via annealing.

Nanostructure Analysis of Anodic Films Formed on Aluminum-Focusing on the Effects of Electric Field Strength and Electrolyte Anions

In this review, the research conducted by the authors on anodic oxide films on aluminum is described, paying particular attention to how the electric field strength, as a factor other than voltage, controls the nanostructures and properties of the films. It will also be indicated what factors contribute to the formation of defects, which, in contrast to the ideal or model film structure, contains a significant number of defects in the film. In addition to electrochemical measurements, the films were examined with a variety of advanced instruments, including electron microscopes, to confirm the “reality of film nanostructure” from a slightly different angle than the conventional view. The following topics on anodic films formed in four types of major anodizing electrolytes are discussed: pore initiation process, steady-state porous structure, sealing mechanism, the relationship between cell parameters and voltage/electric field strength, amount and depth of anion incorporation, electrolyte types, radial branching of pores, atypical pore structures, defect formation mechanism, self-ordering, Al coordination number, and the creation of α-alumina membranes.

Configurable 3D Printed Microfluidic Multiport Valves with Axial Compression

In the last decade, the fabrication of microfluidic chips was revolutionized by 3D printing. It is not only used for rapid prototyping of molds, but also for manufacturing of complex chips and even integrated active parts like pumps and valves, which are essential for many microfluidic applications. The manufacturing of multiport injection valves is of special interest for analytical microfluidic systems, as they can reduce the injection to detection dead volume and thus enhance the resolution and decrease the detection limit. Designs reported so far use radial compression of rotor and stator. However, commercially available nonprinted valves usually feature axial compression, as this allows for adjustable compression and the possibility to integrate additional sealing elements. In this paper, we transfer the axial approach to 3D-printed valves and compare two different printing techniques, as well as six different sealing configurations. The tightness of the system is evaluated with optical examination, weighing, and flow measurements. The developed system shows similar performance to commercial or other 3D-printed valves with no measurable leakage for the static case and leakages below 0.5% in the dynamic case, can be turned automatically with a stepper motor, is easy to scale up, and is transferable to other printing methods and materials without design changes.

Techniques and Materials for Optical Fiber Sensors Sealing in Dynamic Environments with High Pressure and High Temperature

We detail a study of the techniques and sealing materials for optical fiber sensors used in dynamic environments with high pressure (>300 bar) and high temperature (>300 °C). The sealing techniques and materials are the key for the robustness of sensors in harsh dynamic environments, such as large combustion engines. The sealing materials and techniques studied in this work are high-temperature epoxies, metallic polymer, metallic solders, glass solder, cement, brazing and electroless nickel plating. Because obtaining high temperature simultaneously with high pressure is very difficult in the same chamber in the laboratory, we developed a new and simple method to test sealed fibers in these conditions in the laboratory. In addition, some sensors using the materials tested in the laboratory were also field tested in real thermoelectric combustion engines. The study also discusses the methods of fabrication and the cost−benefit ratio of each method.

Design and development of CaCO3nanoparticles enhanced fracturing fluids for effective control of leak-off during hydraulic fracturing of shale reservoirs

This research presents new information about the nanoparticles (NPs) use as a filtrate reducer in the hydraulic fracturing of shale reservoirs. An experimental study was conducted to determine the filtration loss control effectiveness (FLCE) of CaCO₃NPs as an additive in fluids used for hydraulic fracturing of the shale reservoirs. The main objectives were (i-) to determine the mechanisms controlling the NPs enhanced fracturing fluid leak-off rate; (ii-) to determine the optimum NPs concentration, which yields the best FLCE. Spontaneous and forced imbibition experiments (to determine imbibition index) as well as the pressure transmission tests (to determine liquid permeability) were conducted using water based fracturing fluids enhanced by CaCO₃NPs. The imbibition index and the apparent liquid permeability measurements were then used to determine the impact of the NPs concentration (i.e. 0.0, 0.5, 1.0, 2.0 wt%) on the FLCE. In order to understand the filtration control mechanisms of the NPs enhanced fracturing fluids, we have analyzed the field emission scanning electron microscope (FESEM) images of the shale samples, which provided detailed description of how NPs are attached to the shale surface. The experimental results indicated that the CaCO₃NPs have excellent FLCE. The imbibition index and the apparent liquid permeability decreased significantly along with the increasing NPs concentration. The optimum NPs concentration was found to be 1.0 wt%. Analyses of the FESEM images demonstrated that the distribution of the NPs on shale surface is selective. The NPs mainly attached on the rough areas of the shale surface. The process of the NPs adsorption-sealing leads to the reduction of the path of the fluid flow into the shale matrix, and in turn, controls the fracturing fluid filtration. Ultimately, four kinds of sealing patterns were observed including (i-) plugging, (ii-) bridging, (iii-) plugging and accumulation, (iv-) bridging and accumulation.

Retrograde Access to Seal a Large Coronary Vessel Balloon Perforation Without Covered Stent Implantation

The sealing of a large vessel coronary perforation during percutaneous coronary intervention typically requires the deployment of 1 or more covered stents. A novel approach to seal a life-threatening perforation caused by unnoticed wire-exit and balloon dilation, utilizing retrograde techniques, without a covered-stent is described. (Level of Difficulty: Advanced.)

Initial Clinical Experience With a New Conformable Abdominal Aortic Endograft: Aortic Neck Coverage and Curvature Analysis in Challenging Aortic Necks

OBJECTIVES

Aim of this work was to investigate precision of deployment and conformability of a new generation GORE EXCLUDER Conformable Endoprosthesis with active control system (CEXC Device, W.L. Gore and Associates, Flagstaff, AZ, USA) by analyzing aortic neck coverage and curvature.

METHODS

All consecutive elective patients affected by abdominal aortic aneurysm or aortoiliac aneurysm treated at our institution between November 2018 and June 2019 with the new CEXC Device were enrolled. Validated software was adopted to determine the available apposition surface area into the aortic neck, apposition of the endograft to the aortic wall, shortest apposition length (SAL), shortest distance between the endograft fabric and the lowest renal arteries (SFD) and between the endograft fabric and the contralateral renal artery (CFD). Pointwise centerline curvature was also computed.

RESULTS

Twelve patients (10 men, median age 78 years (71.75, 81.0)) with available pre- and postoperative computed tomography angiography (CTA) were included. Technical success was obtained in all the cases. Preoperative median length of the proximal aortic neck was 16.1 mm (10.7, 21.7) and suprarenal (α) and infrarenal (β) neck angulation were, respectively, 28.9° (15.7°, 47.5°) and 75.0° (66.9°, 81.4°). Postoperative median apposition surface coverage was 79% (69.25%, 90.75%) of the available apposition surface. SFD and CFD were 1.5 mm (0.75, 5.25) and 7 mm (4.5, 21.5), respectively. Average curvature over the infrarenal aorta decreased from 25 m^-1 (21.75, 29.0) to 22.5 m^-1 (18.75, 24.5) postoperatively (p=0.02). Maximum curvature did not decrease significantly from 64.5 m^-1 (54.25, 92.0) to 62 m^-1 (41.75, 71.5) (p=0.1).

CONCLUSIONS

Our early experience showed that deployment of the CEXC Device is safe and effective for patients with challenging proximal aortic necks. Absence of significant changes between pre- and postoperative proximal aortic neck angulations and curvature confirms the high conformability of this endograft.

Optical coherence tomography for use in infrared laser sealing of blood vessels

Infrared lasers may provide faster sealing of vascular tissues with less collateral thermal damage and lower device temperatures than radiofrequency and ultrasonic devices currently used for surgery. Optical coherence tomography is tested to image native and thermally coagulated blood vessels, as a potential feedback system.

Low Temperature Sealing of Anodized Aluminum Alloy for Enhancing Corrosion Resistance

Sealing as a post treatment of anodized aluminum is required to enhance the corrosion resistance by filling nanopores, which allow the penetration of corrosive media toward the base aluminum. We designed a mixed sealing solution with nickel acetate and ammonium fluoride by modifying traditional nickel fluoride cold sealing. The concentration of mixed sealing solution affected the reaction rate of sealing and corrosion current density of anodized aluminum alloy. The higher concentration of mixed sealing solution improved the sealing rate, which was represented by a decrease of corrosion current density of anodized aluminum alloy. However, a mixed sealing solution with 2/3 concentration of general nickel fluoride sealing solution operated at room temperature showed the lowest corrosion current density compared to traditional methods (e.g., nickel fluoride cold sealing (NFCS) and nickel acetate hot sealing) and other mixed sealing solutions. Moreover, the mixed sealing solution with 2/3 concentration of general NFCS had a lower risk for over sealing, which increases the corrosion current density by excessive dissolution of anodic oxide. Therefore, the mixed sealing solution with optimized conditions designed in this work possibly provides a new method for enhancing the corrosion resistance of anodized aluminum alloys.

Characterization of Glass-Ceramic Sealant for Solid Oxide Fuel Cells at Operating Conditions by Electrochemical Impedance Spectroscopy

A commercially available glass-ceramic composition is applied on a ferritic stainless steel (FSS) substrate reproducing a type of interface present in solid oxide fuel cells (SOFCs) stacks. Electrochemical impedance spectroscopy (EIS) is used to study the electrical response of the assembly in the temperature range of 380–780 °C and during aging for 250 h at 780 °C. Post-experiment analyses, performed by means of X-ray diffraction (XRD), and along cross-sections by scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis, highlight the microstructural changes promoted by aging conditions over time. In particular, progressive crystallization of the glass-ceramic, high temperature corrosion of the substrate and diffusion of Fe and Cr ions from the FSS substrate into the sealant influence the electrical response of the system under investigation. The electrical measurements show an increase in conductivity to 5 × 10⁻⁶ S∙cm⁻¹, more than one order of magnitude below the maximum recommended value.

Improved Graphene Blisters by Ultrahigh Pressure Sealing

Graphene is a very attractive material for nanomechanical devices and membrane applications. Graphene blisters based on silicon oxide microcavities are a simple but relevant example of nanoactuators. A drawback of this experimental setup is that gas leakage through the graphene-SiO₂ interface contributes significantly to the total leak rate. Here, we study the diffusion of air from pressurized graphene drumheads on SiO₂ microcavities and propose a straightforward method to improve the already strong adhesion between graphene and the underlying SiO₂ substrate, resulting in reduced leak rates. This is carried out by applying controlled and localized ultrahigh pressure (>10 GPa) with an atomic force microscopy diamond tip. With this procedure, we are able to significantly approach the graphene layer to the SiO₂ surface around the drumheads, thus enhancing the interaction between them, allowing us to better seal the graphene-SiO₂ interface, which is reflected in up to ∼ 4 times lower leakage rates. Our work opens an easy way to improve the performance of graphene as a gas membrane on a technological relevant substrate such as SiO₂.

Sealing Graphene Nanodrums

Despite theoretical predictions that graphene should be impermeable to all gases, practical experiments on sealed graphene nanodrums show small leak rates. Thus far, the exact mechanism for this permeation has remained unclear, because different potential leakage pathways have not been studied separately. Here, we demonstrate a sealing method that consists of depositing SiO₂ across the edge of suspended multilayer graphene flakes using electron beam-induced deposition. By sealing, leakage along the graphene-SiO₂ interface is blocked, which is observed to result in a reduction in permeation rate by a factor of 10⁴. The experiments thus demonstrate that gas flow along the graphene-SiO₂ interface tends to dominate the leak rate in unsealed graphene nanodrums. Moreover, the presented sealing method enables the study of intrinsic gas leakage through graphene membranes and can enable hermetic graphene membranes for pressure sensing applications.

Development of a catheter-based technique for endoluminal radiofrequency sealing of pancreatic duct

Introduction: Endoluminal sealing of the pancreatic duct by glue or sutures facilitates the management of the pancreatic stump. Our objective was to develop a catheter-based alternative for endoluminal radiofrequency (RF) sealing of the pancreatic duct. Materials and methods: We devised a novel RF ablation technique based on impedance-guided catheter pullback. First, bench tests were performed on ex vivo models to tune up the technique before the in vivo study, after which endoluminal RF sealing of a ∼10 cm non-transected pancreatic duct was conducted on porcine models using a 3 Fr catheter. After 30 days, sealing effectiveness was assessed by a permeability test and a histological analysis. Results: The RF technique was feasible in all cases and delivered ∼5 W of power on an initial impedance of 308 ± 60 Ω. Electrical impedance evolution was similar in all cases and provided guidance for modulating the pullback speed to avoid tissue sticking and achieve a continuous lesion. During the follow-up the animals rate of weight gain was significantly reduced (p < 0.05). Apart from signs of exocrine atrophy, no other postoperative complications were found. At necropsy, the permeability test failed and the catheter could not be reintroduced endoluminally, confirming that sealing had been successful. The histological analysis revealed a homogeneous exocrine atrophy along the ablated segment in all the animals. Conclusions: Catheter-based RF ablation could be used effectively and safely for endoluminal sealing of the pancreatic duct. The findings suggest that a fully continuous lesion may not be required to obtain complete exocrine atrophy.

Sealing of superior semicircular canal dehiscence is associated with improved balance outcomes postoperatively versus plugging of the canal in middle fossa craniotomy repairs: a case series

OBJECTIVE

The authors compared postoperative symptoms between patients with sealed and those with plugged semicircular canal dehiscence repairs.

METHODS

In total, 136 ears from 118 patients who underwent surgical repair for semicircular canal dehiscence were identified via chart review. Data from postoperative MRI scans showing preservation or loss of semicircular canal fluid signal and postoperative reports of autophony, amplification, aural fullness, tinnitus, hyperacusis, hearing loss, vertigo, dizziness, disequilibrium, oscillopsia, and headache were amalgamated and analyzed.

RESULTS

Patients with preservation of fluid signal were far less likely to have dizziness postoperatively (p = 0.007, OR 0.158, 95% CI 0.041-0.611). In addition, these patients were more likely to have tinnitus postoperatively (p = 0.028, OR 3.515, 95% CI 1.145-10.787).

CONCLUSIONS

The authors found that superior semicircular canal dehiscence patients who undergo sealing without plugging have improved balance outcomes but show more tinnitus postoperatively than patients who undergo plugging.

[A rapid pathological preparation method for composite material observation]

Objective

To explore a simple and rapid pathological slices method to observe the porous structure and the composition distribution of composite materials.

Methods

Taking polyurethane/small intestinal submucosa (PU/SIS) composite as an example, PU/SIS was OCT-embedded and sliced into sections by frozen section technology, after which general observation of the section integrity was carried out. After dyed with water-soluble eosin in alcoholic solution, the staining effect and the porous structure of the composite were observed under light field microscope. Sections were sealed with five different sealing methods. Group A: sealing piece using glycerogelatin method; group B: anhydrous alcohol dehydration→transparency using TO transparent reagent→sealing piece using neutral quick drying glue; group C: color separation using deionized water→air-drying→sealing piece using neutral quick drying glue; group D: air-drying→transparency using TO transparent reagent→sealing piece using neutral quick drying glue; group E: air-drying→sealing piece using neutral quick drying glue. Then, the morphology and the components distribution of the composite were observed under light field microscope, and the simple and feasible method was selected as optimum method.

Results

From general observation, the frozen section of the PU/SIS composite, which was 6 μm in thickness, was complete and continuous. Although the outline of the material and the porous structure in the sections could be observed clearly under light field microscope, the two components still could not be identified by using eosin staining method. After sealing piece, the material components in groups A, B, and C still could not be identified or be dissolved and deformed; the morphology of the material in groups D and E were preserved and the two components in the composite were clearly visible.

Conclusion

The morphology and the components distribution of PU/SIS frozen sections can be characterized after soluble eosin staining and neutral quick drying glue sealing.

Evaluation of sealing abilitiy of mineral trioxide aggregate mixed with propylene glycol as a root canal sealer: A in vitro study

BACKGROUND

Sealing ability is one of the most important features of endodontic sealers. The main goal of the present study was to compare sealing ability of mineral trioxide aggregate (MTA)-propylene glycol (PG) with two commonly used resin-based and MTA-based sealers.

MATERIALS AND METHODS

In This in vitro study Seventy extracted single-root teeth were used. Canal preparation was carried out using hand and RaCe rotary files. Ten teeth were used as control. The root canals in positive and negative control groups were left empty. Remaining 60 teeth were randomly divided into following four groups (n = 15): In Group 1, the canals were dried using paper cones and obturated using MTA-PG sealer. In Group 2, saline was removed from canal using a syring, but paper cones were not used. Obturation was done using MTA-PG sealer. In Groups 3 and 4, the canals were dried using paper cones and obturated with AH26 and MTA Fillapex, respectively. Two-chamber method was used to evaluate bacterial leakage using Enterococcus faecalis (ATCC 29212). Turbidity of the lower chambers was checked every day during 90 days. Chi-square, Kaplan-Meier analysis, and logrank tests were used to compare groups regarding leaked samples at the end of the study. The level of significance was set at 0.05.

RESULTS

There was no significant difference among groups regarding rate of leakage throughout the study. However, at the end of the study, the groups were statistically different regarding leaked samples (P = 0.034). MTA Fillapex and MTA-PG in dry canal showed the most and least leaked samples at the end of the study, respectively (P < 0.05).

CONCLUSION

MTA mixed with PG has superior sealing ability than MTA Fillapex.

Effects of Sealing Marginal Occlusal Defects of Composite Restorations with a Nanofiller-Reinforced Flowable Resin Composite: A Double-Blind, Randomised Clinical Trial with One-Year Follow-Up

PURPOSE

To evaluate the 6-and 12-month performance of microrepairs of marginal occlusal microdefects of resin composite restorations in a group of patients with high caries risk.

MATERIALS AND METHODS

Thirty-five patients with at least three resin composite restorations with marginal occlusal defects were randomly distributed into three treatment groups: (1) sealed with flowable resin composite; (2) sealed with resin-based sealant; or (3) control. Restorations in all groups were assessed using World Dental Federation (FDI) criteria at three time points: baseline, and at 6 and 12 months after sealing.

RESULTS

After 1 year, 32 patients were examined. Of all the repaired restorations, those of the flowable resin composite (RC) group maintained an FDI value of 1 for marginal occlusal adaptation for 81.3% of the restorations at 6 and 78.1% at 12 months. The resin-based sealant group kept a value of 1 for the same parameter on 65.6% of restorations at 6 and 50% at 12 months with a statistically significant difference (p= 0.024) between the two time periods. There was a statistically significant difference between the two groups at the 12-month comparison (p = 0.015).

CONCLUSIONS

Occlusal RC restorations that were sealed using either a resin-based sealant or a nanofilled flowable RC benefited from improved clinical status after 12 months. Use of the latter presented the better clinical performance of the two by providing a higher rate of total retention of sealing materials.

Tightly Sealed 3D Lipid Structure Monolithically Generated on Transparent SU-8 Microwell Arrays for Biosensor Applications

Artificial lipid membranes are excellent candidates for new biosensing platforms because their structures are similar to cell membranes and it is relatively easy to modify the composition of the membrane. The freestanding structure is preferable for this purpose because of the more manageable reconstitution of the membrane protein. Therefore, most of the lipid membranes for biosensing are based on two-dimensional structures that are fixed on a solid substrate (unlike floating liposomes) even though they have some disadvantages, such as low stability, small surface area, and potential retention of solvent in the membrane. In this paper, three-dimensional freestanding lipid bilayer (3D FLB) arrays were fabricated uniformly on SU-8 microwells without any toxic solvent. The 3D FLBs have better stability and larger surface area due to their cell-like structure. In order to improve the sealing characteristics of the 3D FLBs, the applied frequency of the ac field was controlled during the electroformation. The 3D FLBs were observed through transparent SU-8 microwell arrays using confocal microscopy and demonstrated perfect sealing until 5.5 days after the electroformation at more than 1 kHz. Also, the details of the sealing of a fixed 3D freestanding lipid structure were discussed for the first time. The unilamellarity and biofunctionality of the 3D FLBs were verified by a transport protein (α-hemolysin) assay.

One-Step Laser Encapsulation of Nano-Cracking Strain Sensors

Development of flexible strain sensors that can be attached directly onto the skin, such as skin-mountable or wearable electronic devices, has recently attracted attention. However, such flexible sensors are generally exposed to various harsh environments, such as sweat, humidity, or dust, which cause noise and shorten the sensor lifetimes. This study reports the development of a nano-crack-based flexible sensor with mechanically, thermally, and chemically stable electrical characteristics in external environments using a novel one-step laser encapsulation (OLE) method optimized for thin films. The OLE process allows simultaneous patterning, cutting, and encapsulating of a device using laser cutting and thermoplastic polymers. The processes are simplified for economical and rapid production (one sensor in 8 s). Unlike other encapsulation methods, OLE does not degrade the performance of the sensor because the sensing layers remain unaffected. Sensors protected with OLE exhibit mechanical, thermal, and chemical stability under water-, heat-, dust-, and detergent-exposed conditions. Finally, a waterproof, flexible strain sensor is developed to detect motions around the eye, where oil and sweat are generated. OLE-based sensors can be used in several applications that are exposed to a large amount of foreign matter, such as humid or sweaty environments.

Pit and Fissure Sealants-A Comprehensive Review

Even in the 21st century, dental caries is considered a global burden, severely upsetting the health and quality of life of those affected. Apart from the usage of fluoride and regular oral hygiene, one of the most important prophylactic approaches against the occurrence of caries is the sealing of pits and fissures. However, the rapid progress of new materials and applications for sealing pits and fissures also raises new questions about their correct application. Recent literature on pit and fissure sealing, caries prevention, as well as caries risk assessment for both children and adults was reviewed. This report provides a general overview of pit and fissure sealing, the materials used for sealing occlusal surfaces, as well as indications and possible side effects. The conclusions are that sealing pit and fissures of primary and permanent teeth is an effective method for preventing and arresting caries. However, regular checkups must be conducted to avoid advanced tooth decay attributable to leakages in the sealing.

Transvesicoscopic Bipolar Sealing of Vesicovaginal Fistula

Introduction: Vesicovaginal fistula (VVF) is a problem that physically and psychologically debilitates the patient. Options for treatment of VVF include transabdominal, transvaginal, transvesical, laparoscopic, and robotic repair or minimally invasive methods such as fulguration. We describe a novel minimally invasive technique: transvesicoscopic bipolar sealing of the vesicovaginal fistula (TBSF).

Case Presentation: We carried out the transvesicoscopic sealing of VVF with 5 mm of diameter on a 46-year-old woman, who had a failed conservative treatment with a Foley catheter placement. The patient was informed about the modified surgical procedure before operation. The fistula tract was sealed by using an electrothermal bipolar vessel sealer through a 5-mm transvesical ports. The patient was discharged on the first postoperative day and was on anticholinergic medications after the operation. The patient remained dry after the removal of the catheter at the third postoperative week.

Conclusion: In select cases of VVF, TBSF may be effectively used for closure of the fistula tract.

The cold ceramic material

The purpose of this paper was to review the composition, sealing ability, biocompatibility and various physical properties of cold ceramic (CC) material that potentially used as a root filling material. The review of the articles was performed by electronic and manual searching methods regarding the properties of CC from November 2000 to May 2016. The results revealed that there were many published reports carried out on the properties of CC. Only one article had extensively studied the composition of CC, five studies had investigated the sealing ability of CC, three articles had studied the biocompatibility, and some studies had investigated the radiopacity, setting time, pH value, and solubility of CC. It was concluded that CC material had good potential for endodontic use. Furthermore, clinical studies are needed in these areas.

Comparison of the Percentage of Voids in the Canal Filling of a Calcium Silicate-Based Sealer and Gutta Percha Cones Using Two Obturation Techniques

This study evaluated the root-filling quality of a calcium silicate-based sealer and gutta percha (GP) cones by measuring the percentage of voids. Twenty artificial molar teeth were divided into two groups: one obturated using the single-cone (SC) technique, and the other using the continuous wave (CW) technique. Obturation was performed with GP cones and Endoseal MTA (mineral trioxide aggregate, Maruchi, Wonju, Korea). Obturated teeth were scanned using microcomputed tomography, and the percentage of void volume was calculated in the apical and coronal areas. A linear mixed model was used to determine the differences between the two techniques (p < 0.05). The percentage of voids between the filling materials and root canal walls was not significantly different between the two obturation methods (p > 0.05), except for the CW group, which demonstrated a significantly higher void volume in the coronal area of the distal canal (p < 0.05). The percentage of voids inside the filling material was significantly higher in the CW groups for all of the comparisons (p < 0.05), except in the apical area of the distal canal (p > 0.05). The voids between the filling material and canal wall in the apical area were not significantly different between the two techniques.

One successful primary closure case of bronchopleural fistula after pneumonectomy by a new method

One case of successful primary closure of a bronchopleural fistula (BPF) after right pneumonectomy by sealing from both inside the chest cavity and bronchus is reported. The patient was a 47-year-old man who underwent right pneumonectomy due to right lung total collapse and atelectasis which was long-term compressed by a huge cyst inside the right chest cavity. A BPF was found on day 20 after surgery. A thoracotomy approach was performed because it was difficult to find an appropriate location for close drainage. Once the effusion and bloody coagulum was cleaned up from the right chest cavity, it was still difficult to find the bronchial stump because of the thick pleural fibrous membranes, and no visible fistula was found. Inside the chest cavity, a bright spot could be seen when the bronchoscope was inserted to the right bronchial stump. Anastomotic glue (OB Glue) was smeared on the bright spot and NEOVEIL (Gunze Co., Tokyo, Japan) was used to cover and reinforce the area. Meanwhile OB Glue (Gzbme Co., Guangzhou, China) was placed on the bronchial stump by bronchoscope. Closed drainage was performed after the operation. The patient recovered well having an uncomplicated postoperative course and was discharged 7 days after the treatment.

Radon Mitigation Approach in a Laboratory Measurement Room

Radon gas is the second leading cause of lung cancer, causing thousands of deaths annually. It can be a problem for people or animals in houses, workplaces, schools or any building. Therefore, its mitigation has become essential to avoid health problems and to prevent radon from interfering in radioactive measurements. This study describes the implementation of radon mitigation systems at a radioactivity laboratory in order to reduce interferences in the different works carried out. A large set of radon concentration samples is obtained from measurements at the laboratory. While several mitigation methods were taken into account, the final applied solution is explained in detail, obtaining thus very good results by reducing the radon concentration by 76%.

Oral Function Improves Interfacial Integrity and Sealing Ability Between Conventional Glass Ionomer Cements and Dentin

The aim of this study was to investigate if load cycling affects interfacial integrity of glass ionomer cements bonded to sound- or caries-affected dentin. A conventional glass ionomer, Ketac Bond, and a resin-modified glass ionomer (Vitrebond Plus), were applied to dentin. Half of the specimens were load cycled. The interfaces were submitted to dye-assisted confocal microscopy evaluation. The unloaded specimens of sound and carious dentin were deficiently hybridized when Ketac Bond was used. Ketac Bond samples showed an absorption layer and an adhesive layer that were scarcely affected by fluorescein penetration (nanoleakage), in sound dentin. Nevertheless, a higher degree of micropermeability was found in carious dentin. In Ketac Bond specimens, load cycling improves the sealing capability and remineralization at the cement-dentin interface as porosity and nanoleakage was reduced. In contrast, samples treated with Vitrebond Plus exhibited a Rhodamine B-labeled absorption layer with scarce nanoleakage in both sound and carious unloaded dentin. The adhesive layer was affected by dye sorption throughout the porous cement-dentin interface. Samples treated with Vitrebond Plus had significant increases in nanoleakage and cement-dye sorption after load cycling. Within the limitations of an in vitro study, it is expected that conventional glass ionomers will provide major clinical efficacy when applied to carious-affected or sound dentin.

Infrared laser sealing of porcine vascular tissues using a 1,470 nm diode laser: Preliminary in vivo studies

INTRODUCTION

Infrared (IR) lasers are being explored as an alternative to radiofrequency (RF) and ultrasonic (US) devices for rapid hemostasis with minimal collateral zones of thermal damage and tissue necrosis. Previously, a 1,470 nm IR laser sealed and cut ex vivo porcine renal arteries of 1-8 mm diameter in 2 seconds, yielding burst pressures greater than 1,200 mmHg and thermal coagulation zones less than 3 mm. This preliminary study describes in vivo testing of a handheld laser probe in a porcine model.

METHODS

A handheld prototype with vessel/tissue clasping mechanism was tested on 73 blood vessels less than 6 mm diameter using 1,470 nm laser power of 35 W for 1-5 seconds. Device power settings, irradiation time, tissue type, vessel diameter, and histology sample number were recorded for each procedure. The probe was evaluated for hemostasis after sealing isolated and bundled arteriole/venous (A/V) vasculature of porcine abdomen and hind leg. Sealed vessel samples were collected for histological analysis of lateral thermal damage.

RESULTS

Hemostasis was achieved in 57 of 73 seals (78%). The probe consistently sealed vasculature in small bowel mesentery, mesometrium, and gastrosplenic and epiploic regions. Seal performance was less consistent on hind leg vasculature including saphenous arteries/bundles and femoral and iliac arteries. Collagen denaturation averaged 1.6 ± 0.9 mm in eight samples excised for histologic examination.

CONCLUSIONS

A handheld laser probe sealed porcine vessels, in vivo. Further probe development and laser parameter optimization is necessary before infrared lasers may be evaluated as an alternative to RF and US vessel sealing devices. Lasers Surg. Med. 49:366-371, 2017. © 2016 Wiley Periodicals, Inc.

Polyethylene Glycol-Based Synthetic Hydrogel Sealant for Closing Vitrectomy Wounds: An In Vivo and Histological Study

Purpose

We conducted an in vivo study using Dutch pigmented rabbit eyes to test the usefulness of polyethylene glycol (PEG) sealant for the closure of sutureless sclerotomies in microincisional vitrectomy surgery (MIVS).

Methods

Three-port, 23-gauge vitrectomy was performed on rabbit eyes. After air leakage was confirmed by the application of 0.625% povidone–iodine at the sclerotomy site, PEG sealant was subconjunctivally injected using a 27-gauge needle through conjunctival incisions to cover the sclerotomy wounds, following which it was polymerized by the application of xenon light for 60 seconds. Ophthalmological examinations and intraocular pressure measurements were conducted the day before and 1, 3, 5, and 7 days after surgery. The eyes were enucleated for histological evaluation 7 days after surgery.

Results

PEG sealant was rapidly polymerized by the application of xenon light after subconjunctival injection, and it firmly sealed the sclerotomies without air leakage, as confirmed by povidone–iodine dropping, in all cases. Conjunctival and scleral wounds closed with PEG sealant were successfully attached and remained intact till the end of the follow-up period. There was no sign of postoperative hypotony or infection in any eye, and no adverse effects of PEG sealant were found. In histological examination, linear scar formation and eosinophilic staining of collagen fibers were observed at the sclerotomy sites, while the sclerotomy tunnels appeared tightly closed.

Conclusions

PEG sealant can be useful for the closure of sutureless 23-gauge vitrectomy incisions in rabbits.

Translational Relevance

The PEG sealant may become an effective option for closing vitrectomy incisions including pediatric cases.

Control of bleeding in surgical procedures: critical appraisal of HEMOPATCH (Sealing Hemostat)

The need for advanced hemostatic agents increases with the complexity of surgical procedures and use of anticoagulation and antiplatelet treatments. HEMOPATCH (Sealing Hemostat) is a novel, advanced hemostatic pad that is composed of a synthetic, protein-reactive monomer and a collagen backing. The active side is covered with a protein-reactive monomer: N-hydroxysuccinimide functionalized polyethylene glycol (NHS-PEG). NHS-PEG rapidly affixes the collagen pad to tissue to promote and maintain hemostasis. The combined action of the NHS-PEG and collagen is demonstrated to have benefit relative to other hemostatic agents in surgery and preclinical surgical models. This paper reviews the published investigations and case reports of the hemostatic efficacy of HEMOPATCH, wherein HEMOPATCH is demonstrated to be an effective, easy-to-use hemostatic agent in open and minimally invasive surgery of patients with thrombin- or platelet-induced coagulopathies.

Consistency and sealing of advanced bipolar tissue sealers

Objectives

The aim of this study was to evaluate two commonly used advanced bipolar devices (ENSEAL^® G2 Tissue Sealers and LigaSure™ Blunt Tip) for compression uniformity, vessel sealing strength, and consistency in bench-top analyses.

Methods

Compression analysis was performed with a foam pad/sensor apparatus inserted between closed jaws of the instruments. Average pressures (psi) were recorded across the entire inside surface of the jaws, and over the distal one-third of jaws. To test vessel sealing strength, ex vivo pig carotid arteries were sealed and transected and left and right (sealed) halves of vessels were subjected to burst pressure testing. The maximum bursting pressures of each half of vessels were averaged to obtain single data points for analysis. The absence or presence of tissue sticking to device jaws was noted for each transected vessel.

Results

Statistically higher average compression values were found for ENSEAL^® instruments (curved jaw and straight jaw) compared to LigaSure™, P<0.05. Moreover, the ENSEAL^® devices retained full compression at the distal end of jaws. Significantly higher and more consistent median burst pressures were noted for ENSEAL^® devices relative to LigaSure™ through 52 firings of each device (P<0.05). LigaSure™ showed a significant reduction in median burst pressure for the final three firings (cycles 50–52) versus the first three firings (cycles 1–3), P=0.027. Tissue sticking was noted for 1.39% and 13.3% of vessels transected with ENSEAL^® and LigaSure™, respectively.

Conclusion

In bench-top testing, ENSEAL^® G2 sealers produced more uniform compression, stronger and more consistent vessel sealing, and reduced tissue sticking relative to LigaSure™.

Caries infiltrant combined with conventional adhesives for sealing sound enamel in vitro

OBJECTIVE

To test the null hypothesis that combining low-viscosity caries infiltrant with conventional adhesive resins would not improve sealing of sound enamel against demineralization in vitro.

MATERIALS AND METHODS

Bovine enamel discs (N = 60) with diameter of 3 mm were randomly assigned to six groups (n = 10). The discs were etched with 37% phosphoric acid for 30 seconds and treated with resins of different monomer content forming the following groups: (1) Icon (DMG), (2) Transbond XT Primer (3M ESPE), (3) Heliobond (Ivoclar Vivadent), (4) Icon + Transbond XT Primer, and (5) Icon + Heliobond. Untreated etched samples served as the negative control. Specimens were subjected to demineralization by immersion in hydrochloric acid (pH 2.6) for 80 hours. Calcium dissolution into the acid was assessed by colorimetric analysis using Arsenazo III method at 16-hour intervals. Groups presenting high protection against demineralization were subjected to further acidic challenge for 15 days with calcium measurements repeated at 24-hour intervals. Data were analyzed by Kruskal-Wallis test and Mann-Whitney U-test.

RESULTS

Untreated specimens showed the highest amount of demineralization. Icon and Transbond XT primer decreased the mineral loss significantly compared to the control. Heliobond performed significantly better than both Icon and Transbond XT primer. Combination of Icon both with Transbond XT primer or Heliobond served as the best protective measures and maintained the protective effect for the additional 15-day acidic challenge.

CONCLUSIONS

Within the limitations of this in vitro study, it could be concluded that the use of low-viscosity caries infiltrant prior to application of the tested conventional adhesives increases their protective effect against demineralization.

Anastomotic stability and wound healing of colorectal anastomoses sealed and sutured with a collagen fleece in a rat peritonitis model. Asian J Surg. 2014;37:35-45. [PMID: 23978425 DOI: 10.1016/j.asjsur.2013.07.008]

BACKGROUND/OBJECTIVE

Anastomotic insufficiency is associated with increased morbidity and mortality. A collagen fleece that supports anastomosis is effective for preventing anastomosis insufficiency. The objective of this study was to compare between the stability of sutured anastomoses and that of anastomoses sealed with a thrombin/fibrinogen-coated collagen fleece in a rat peritonitis model.

METHODS

In 72 male Wistar rats, peritonitis was induced with a specially prepared human fecal solution. Surgery at the rectosigmoid junction was performed 24-36 hours later. The different anastomotic techniques used were circular sutured anastomoses, semicircular sutured anastomosis and closure of the anterior wall with collagen patch, and complete closure with a collagen fleece. Bursting pressure, histology of anastomosis, mRNA expression of collagen types I and III, matrix metalloproteinase-13, and vascular endothelial growth factor (VEGF) were investigated after 24 hours, 72 hours, and 120 hours.

RESULTS

All animals developed peritonitis of comparable severity. There were no differences in bursting pressures between the three suture techniques after 24 hours, 72 hours, or 120 hours. Anastomoses sealed with a collagen fleece appeared to be slightly less stable only at 24 hours, whereas they appeared to be more stable than semisutured or fully sutured anastomoses at 72 hours and 120 hours. Sealing with a collagen fleece was associated with an increase in granulation tissue, higher mRNA levels for collagen types I and III, and higher VEGF compared to sutured anastomoses.

CONCLUSION

The use of a thrombin/fibrinogen-coated collagen fleece showed similar efficacy to conventional sutures in colorectal anastomoses in the presence of peritonitis inflammation, and may provide additional benefits due to an increase in mature granulation tissue.

Sealing ability of cements in root canals prepared for intraradicular posts

This research evaluated the sealer ability of 2 temporary filling materials (white Cimpat and IRM) and 1 restorative cement (glass ionomer), in canals prepared for root posts. Sixty human palatal roots of maxillary first molars were used. They were divided into 3 groups, according to the cements used: Group I (Cimpat), Group II (IRM) and Group III (glass ionomer). The roots were rendered impermeable, filled with the respective cements and soon after immersed into 0.2% Rhodamine B dye and maintained for 72 hours in an oven for 37 degrees C. Microleakage was measured with a light microscope, cutting the roots longitudinally in buccolingual direction. The results showed that Group I presented significantly more leakage than Groups II and III, which were not significantly different from each other.