The Splash Zone: Efficacy of Ureteroscopic Adapters in Containing Hazardous Leak

The development of new-generation flexible ureteroscopes has improved diagnostic and therapeutic endourological procedures. Despite technical improvement irrigation flow and quality of vision is often unsatisfactory. This study describes inter-manufactural differences in the latest available flexible ureteroscopes in terms of irrigation flow in correlation to different deflection angles and the use of 1.9 Fr. stone baskets. Irrigation flow measurements were performed in five new-generation flexible ureterorenoscopes with 3.6 Fr. working channels: Wolf (Uretero-Renoscope 270°), Storz (Flex-X² and Flex-X(c)), ACMI (DUR-D) and Olympus (URF Type P5) in 0°, 90° and 180° deflection. All measurements were carried out five times with an empty working channel as well as with inserted 1.9 Fr. stone baskets. Mean flow rates with empty instruments (SD) counted 50ml/min (0.8), 50 (1.0), 48 (1.7), 48 (1.6) and 44 (0.7) for ACMI, Wolf, Storz (FlexX² and Flex-X(c)), and Olympus, respectively. Stone baskets significantly reduced irrigation flows in all tested ureteroscopes (p<0.05). In channels with inserted baskets, the highest flow rates were measured for ACMI and Wolf with 12ml/min (0.7) each. The lowest reduction of flow rate was detected in the ACMI and the Wolf ureteroscope (76.0%, 38ml/min each). Measurements after flexion showed no significant differences between the ureteroscopes. Latest generation of flexible ureteroscopes offer various new product developments, including excellent deflection capacities. This study showed inter-manufactural differences in terms of irrigation flow rates with either empty or occupied working channels resulting in significant alterations in endoscopic view.

Performance comparison of intraosseous devices and setups for infusion of whole blood in a cadaveric swine bone model.

With a new generation of flexible ureterorenoscopes, a new area in stone management is emerging. Limitation of vision with these new instruments is often caused by insufficient irrigation flow, especially when using instruments like stone baskets, resulting from partial obstruction of the working and irrigation channel with these instruments. Empirically, new available smaller stone baskets seem to dramatically improve irrigation and therefore vision in clinical use. The goal of this study was to show objective differences in basket diameters and flow rates in an in vitro setting. Diameters and irrigation flows in flexible ureterorenoscopes depending on different sizes of stone baskets (Fr. 1.5-1.7-1.9-2.2-2.4-3.0) and different deflections were measured. The measured diameter of the baskets varied within the first 20 cm and the true measured size varied from the manufacturer's specified size to a different extent. The new generation of 1.5 and 1.7 Fr. baskets improved irrigation flow, even compared to the smallest commonly used baskets, up to 68%. Interestingly, deflection did not influence irrigation flow. This study confirmed the subjective impression of inadequate description of relevant basket diameters as well as that of a significant improvement of irrigation flow with the newest generation of stone baskets with smaller diameters.

Purpose: To evaluate in vitro the maximum pressure generated in an artificial kidney model when people of different levels of strengths used various irrigation systems. Materials and Methods: Fifteen people were enrolled and divided into three groups based on their strengths. Individual strength was evaluated according to the maximum pressure each participant was able to achieve using an Encore™ Inflator. The irrigation systems evaluated were as follows: T-Flow™ Dual Port, Hiline™, continuous flow single action pumping system (SAPS™) with the system close and open, Irri-flo II™, a simple 60-mL syringe, and Peditrol™. Each irrigation system was connected to URF-V2 ureteroscope, which was inserted into an artificial kidney model. Each participant was asked to produce the maximum pressure possible with every irrigation device. Pressure was measured with the working channel (WC) empty, with a laser fiber, and a basket inside. Results: The highest pressure was achieved with the 60 mL-syringe system and the lowest with SAPS continuous version system (with continuous irrigation open), compared to the other irrigation devices (p < 0.0001). Irrespective of the irrigation system, there was a significant difference in the pressure between the WC empty and when occupied with the laser fiber or the basket inside it (p < 0.0001). The stratification between the groups showed that the most powerful group could produce the highest pressure in the kidney model with all the irrigation devices in almost any situation. The exception to this was the T-Flow system, which was the only device where no statistical differences were detected among these groups. Conclusion: The use of irrigation systems can often generate excessive pressure in an artificial kidney model, especially with an unoccupied WC of the ureteroscope. Depending on the strength of force applied, very high pressure can be generated by most irrigation devices irrespective of whether the scope is occupied or not.

Introduction: The advent of single-use disposable flexible ureteroscopes allows for rapid prototyping of novel endoscopes. In this regard, we sought to develop a female-specific ureteroscope, with a shorter working length, to account for the female anatomy. We hypothesized that the shorter, female-specific single-use flexible ureteroscope would engender higher irrigation flow at a given pressure than that of the standard-length ureteroscope. Methods: An in vitro analysis of a standard 65 cm Dornier Axis™ ureteroscope and a shorter, 45 cm female-specific Dornier Axis ureteroscope was performed. All other aspects of the endoscopes were identical. Each ureteroscope was oriented vertically and connected to a Thermedx® irrigation system to provide uniform pressurized flow. The average flow rate was computed over five, 2-minute periods at pressure settings of 50, 100, 150, and 200 mm Hg. Data were collected with the working channel unoccupied, after placement of a 200 μm (0.6F) holmium laser fiber and after passage of a 1.7F stone basket. The procedure was then repeated with the endoscopes at maximum deflection. Results: The female gender ureteroscope had significantly higher irrigation flow rates than the standard-length ureteroscope under all conditions by an average of 11% (p < 0.02). The highest average percent increase, 17% (p < 0.001), was seen with the 1.7F NGage® basket in the working channel with the endoscope straight. The maximum angle of deflection was not significantly different between the female gender and standard ureteroscopes with an open working channel (314° vs 315°, p = 0.86), with the 1.7F NGage basket in place (314° vs 315°, p = 0.15), and with the 200 μm holmium laser in place (316° vs 309°, p = 0.09). Conclusions: A 45 cm female gender ureteroscope allows for a higher irrigation flow rate than the standard-length ureteroscope under all test conditions. There is no added benefit with regard to deflection capabilities.

Thulium fiber laser lithotripsy using smaller optical fibers may enable development of miniature ureteroscopes. Two ureteroscope distal tip prototypes were built and characterized. The first design was 4.5-French (Fr) [1.5-mm outer diameter (OD)], five channel tip, housing 200-μm inner diameter (ID) dedicated central channel for insertion of 100-μm core fibers and four surrounding channels, each with 1.5Fr (510-μm ID) for instrumentation, irrigation, imaging, and illumination, respectively. The second design was 6.0-Fr (2.0-mm OD), three-dimensional printed tip with larger, hemispherical common working channel and separate detection port integrated with ring lighting. Standard instruments, including optical fibers, guidewires, and stone baskets, were inserted through working channels to demonstrate feasibility. Gravitational and manual pump-assisted saline irrigation rates were measured. Luminous intensity distribution curves (LIDCs) were modeled for both ring and conventional lighting designs. Imaging was conducted using 3000, 6000, and 10,000pixel, miniature, flexible endoscopes with 0.4-, 0.6-, and 0.9-mm OD, to differentiate between urinary stones and ureter wall, for potential clinical application. The multichannel ureteroscope tip with 1.5-Fr working channel yielded a gravitational saline flow rate of 3.9 ± 0.2 mL / min compared to 31.3 ± 0.6 mL / min for standard (3.6Fr) ureteroscope channel. Manual, pump-assisted irrigation increased flow rate to 32.5 ± 3.0 mL / min. The 6000pixel, 0.6-mm OD, flexible endoscope provided a balance of clear differentiation between stones and ureter wall and sufficiently small OD. A ring lighting configuration provided more uniform illumination than conventional cross-lighting geometry as demonstrated by LIDCs. With further development, these miniature ureteroscope tip designs may be integrated into a fully functional ureteroscope to permit ureteral access with minimal trauma and improved patient safety and comfort.

Aims and ObjectivesIntraosseous (IO) administration of medication, fluids and blood products is accepted practice for critically injured patients in whom intravenous (IV) access is not immediately available. However, there are...

Corrosion at splash zones of risers and spool pieces of subsea pipelines, can be severe reading corrosion rates up to 1mm/year, due to the lack of effectiveness of cathodic protection and coating damages caused either by disbondment or object impact. So, it's highly recommended that this zone have a specific inspection plan combined with a special inspection program for preventing the occurrence of failure, as well as following up the evolution of any failure mechanism which eventually might be present. Traditionally inspection techniques applied at splash zone are: general visual inspection and local thickness measurement. However these techniques are not practical as they require marine growth and even coating removal. After an event caused by corrosion at splash zone, a literature review was carried out to produce the state of the art of non intrusive technological solutions for inspecting the corroded areas of splash zones of risers and spools. This paper describes the results of laboratory tests carried out with some of the identified technologies on full scale riser samples. Test results indicate that technologies such as guided waves and Saturated Low Frequency Eddy Current (SLOFEC can be complementary alternatives to the splash zone traditional inspection techniques, although the coating type and wall thickness have significant influence on these technologies' sensitivity and probability of detection. These technologies have the capability of inspecting/monitoring large areas of splash zones of risers and spools without marine growth and coating removal. This is an advantage when compared to the traditional inspection techniques. 1. INTRODUCTION Statistical data collected in the last 30 years indicate corrosion as the main failure cause in risers [1]. At splash zone on risers and spool pieces, where cathodic protection is not effective, the higher probability of coating damage due to object impact or coating disbondment turns this zone highly susceptible to corrosion [1,2]. Studies published by U.S. Department of the Interior, Minerals Management Service (MMS) indicate that 92% of corrosion failures occurred in risers in the Gulf of México was caused by external corrosion [1]. In 2000, Chevron communicated a high pressure riser failure in one of their platforms in West Coast of Africa due to severe corrosion at splash zone caused by coating damage. Further studies on all 1027 production risers in that region revealed serious problems in the Integrity Management Program of risers practiced at that time [2]. At Petrobras, a working group was established after events that led to repair/replacement of spools pieces damaged by corrosion at splash zone. This group aimed at searching risers and spools pieces inspection techniques available in the industry, which would be adequate for application in the field. It was identified some technologies, that should be technically evaluated finding their limitations and actual capabilities for further application at Petrobras. This paper describes the laboratory tests results obtained by applying some of these identified technologies on full scale pipe samples.

Background: Proper control of irrigation flowrate during ureteroscopy is important to manage thermal and pressure risks. This task is challenging because flowrate is not directly measured by commercially available ureteroscopic or fluid management systems. However, flowrate can be calculated using a hydrodynamic relationship based on measurable values during ureteroscopy. Objectives of this in vitro study were to (1) calculate inflow resistance for different working channel conditions and then using these values and (2) calculate irrigation flowrate and determine its accuracy across a range of renal pelvis pressures. Materials and Methods: A 16 L container was filled with deionized water and connected by irrigation tubing to a 9.6F single-use ureteroscope. Inflow resistance was determined by plotting flowrate (mass of fluid collected from ureteroscope tip in 60 seconds) vs irrigation pressure (range 0-200 cmH2O). Next, the tip of the ureteroscope was inserted into the renal pelvis of a silicone kidney-ureter model and renal pelvis pressure was measured. In conjunction with the previously determined inflow resistance and known irrigation pressure values, flowrate was calculated and compared with experimentally measured values. All trials were performed in triplicate for working channel conditions: empty, 200 μm laser fiber, 365 μm laser fiber, and 1.9F stone basket. Results: Flowrate was linearly dependent on irrigation pressure for each working channel condition. Inflow resistance was determined to be 5.0 cmH2O/(mL/min) with the 200 μm laser fiber in the working channel and calculated flowrates were within 1 mL/min of measured flowrates. Similar results were seen with a 365 μm laser fiber, and 1.9F basket. Conclusions: Utilizing renal pelvis pressure measurements, flowrate was accurately calculated across a range of working channel conditions and irrigation pressures. Incorporation of this methodology into future ureteroscopic systems that measure intrarenal pressure could provide a real-time readout of flowrate for the urologist and thereby enhance safety and efficiency of laser lithotripsy.

The primary aim was to assess how various flexible ureteroscopes and ureteral access sheath size combinations affected intra-cavity pressures, under excessive irrigation pressures with a pressure bag. The secondary aim was to determine the maximum irrigation pressure that could be applied while still maintaining safe intra-cavity pressures, when a certain sheath-scope combination had resulted in an unsafe intra-cavity pressure in the initial experiment. An in-vitro setup was used to measure intra-cavity pressures across different flexible ureteroscope (6.3-9.6 Fr; Hugemed, Innovex and WiScope) and sheath size (ClearPetra; inner lumen diameter 9.5-12 Fr, lengths 40 and 50cm) combinations. A steady irrigation pressure was delivered via a pressure bag pressurised to 360 mmHg, and a urodynamic machine provided real-time readings of intra-cavity pressure. For each combination, the steady-state intra-cavity pressure was recorded. Combinations generating an unsafe intra-cavity pressure (i.e. intra-cavity pressure of more than 30 mmHg) were re-assessed by gradually reducing the irrigation pressure, until intra-cavity pressure recorded reached 30 mmHg. The corresponding irrigation pressure was then recorded, and the experiment was then repeated with this established safe irrigation pressure to confirm that a safe intra-cavity pressure had been achieved. An intra-cavity pressure of 30 mmHg was taken to be the determined safe threshold for intra-cavity pressure. High intra-cavity pressures were observed with smaller sheaths and larger scopes, exceeding 100 mmHg in some combinations. Longer sheaths tended to generate higher pressures than shorter ones. The use of 12 Fr sheaths or 6.3 Fr scopes appeared to be safe regardless of the paired scope or sheath, even under extreme inflow pressure. Scope and sheath combinations have a significant impact on intra-cavity pressure, and inappropriate combinations may lead to unsafely elevated pressures. Larger sheaths and smaller scopes offer safer pressure profiles, even under high flow or high-pressure irrigation.

The Thulium fiber laser (TFL) is being explored as an alternative laser lithotripter to the Holmium:YAG laser. The TFL's superior near-single mode beam profile enables higher power transmission through smaller fibers with reduced proximal fiber tip damage. Recent studies have also reported that attaching hollow steel tubing to the distal fiber tip decreases fiber degradation and burn-back without compromising stone ablation rates. However, significant stone retropulsion was observed, which increased with pulse rate. In this study, the hollow steel tip fiber design was integrated with a stone basket to minimize stone retropulsion during ablation. A device was constructed consisting of a 100-&mu;m-core, 140-&mu;m-OD silica fiber outfitted with 5-mm-long stainless steel tubing at the distal tip, and integrated with a 1.3-Fr (0.433-mm-OD) disposable nitinol wire basket, to form an overall 1.9-Fr (0.633-mm- OD) integrated device. This compact design may provide several potential advantages including increased flexibility, higher saline irrigation rates through the ureteroscope working channel, and reduced fiber tip degradation compared to separate fiber and stone basket manipulation. TFL pulse energy of 31.5 mJ with 500 &mu;s pulse duration and pulse rate of 500 Hz was delivered through the integrated fiber/basket device in contact with human uric acid stones, ex vivo. TFL stone ablation rates measured 1.5 &plusmn; 0.2 mg/s, comparable to 1.7 &plusmn; 0.3 mg/s (P &gt; 0.05) using standard bare fiber tips separately with a stone basket. With further development, this device may be useful for minimizing stone retropulsion, thus enabling more efficient TFL lithotripsy at higher pulse rates.

Constructing bi-functional Ce-MOF on carbon fiber endowing epoxy coating with excellent anti-corrosion and erosion wear resistance

To compare intrapelvic pressure (IPP) levels achieved during f-URS, mini-PCNL, standard PCNL, and endoscopic combined intrarenal surgery in a kidney model. A silicone model simulating the complete urinary tract was used for all the experiments. We compared: a 9.5Fr f-URS, a 12Fr mini-nephroscope and a 26Fr nephroscope. The irrigation pressure was set at 40 and 193cmH2O. We compared: f-URS-S ± ureteral access sheath (UAS, 10/12Fr, 11/13Fr, 12/14Fr) ± 273μm laser fiber, Mini-PCNL with different sizes of operating sheath (15/16Fr, 16.5/17.5Fr, 21/22Fr) ± 365μm laser fiber, Standard PCNL with an operating sheath of 30Fr ± Lithotripter LithoClast Master 11.4Fr. f-URS: IPP values ranged between 1.4 and 46.2cmH2O. Factors reducing IPP were an irrigation pressure at 40cmH2O, an occupied working channel, and the use of a UAS except with the 10/12Fr at 193cmH2O. Mini-PCNL: IPP values ranged between 2.4 and 39.7cmH2O. Factors reducing IPP were irrigation pressure at 40cmH2O, a large operating sheath (> 15/16Fr). The occupation of the working channel did not affect the IPP at 40 cmH2O, while it decreased at 193cmH2O. Standard PCNL: IPP values ranged between 1.4 and 7.3cmH2O. Occupancy of the working channel did not affect IPP at 40cmH2O, while it increased at 193cmH2O. We recorded for the first time IPP values according to different endourological techniques and configurations. IPP never exceed 50 cmH2O irrespectively of the assessed technique/setup. The factors reducing IPP were a low irrigation pressure (40cmH2O), the use of a UAS or a working sheath appropriate to the diameter of the endoscope, as well as the occupation of the working channel in the case of f-URS.

As surgical technology continues to advance, stone baskets are becoming increasingly miniaturized. We performed a study to define the effect of miniaturized stone baskets on ureteroscope irrigation flow and deflection. We compared the three smallest available stone baskets: Boston Scientific 1.3F OptiFlex, Cook 1.5F N-Circle, and Sacred Heart 1.5F Halo, measuring their effect on irrigant flow and deflection of three flexible ureteroscopes. All devices adversely affected irrigation flow and active deflection of all of the ureteroscopes (P<0.05). The 1.3F device, however, exhibited significantly less of an effect on both parameters. Irrigation flow was 28% greater with the 1.3F device than it was for the 1.5F devices. The device's effect on active deflection was 43% less with the 1.3F device than it was for the 1.5F devices. Any device placed through the working channel of a ureteroscope will have a deleterious effect on the ureteroscope's irrigant flow and active deflection. As the caliber of the device decreases, however, its effect on these parameters appears to be reduced. Our present data suggest that the 1.3F basket has significantly less of an effect on both the irrigant flow and deflection of a flexible ureteroscope than do the 1.5F devices.

New materials have been developed for high pressure marine risers used in tension leg platform (TLP) applications. Modifications of standard AISI 8630 material provide low alloy steel grades which have good fracture toughness and excellent fatigue properties under high stress conditions, and are readily weldable. Materials and welding procedures are reviewed in light of increased performance demands forTLP applications, and considering design criteria established by the relevant certifying authorities. Work performed on the drilling and export risers for the industry's first (and to date, only) TLP installation is presented, with reference to monitoring and quality control activities involved in fabrication of those systems.