Irrigation Flow Rate Research Articles

Rate-controlled intraventricular endoscopic irrigation via bipolar foot pedal activation: technical note.

Irrigation during intraventricular endoscopic surgery is critical for visualization, with normal intracranial pressure maintained by balancing fluid ingress and egress. Although irrigation is typically achieved through manual manipulation of inexact stopcocks, the authors have developed a rate-controlled, foot pedal-activated system for precise intraventricular irrigation by using a standard irrigating bipolar electrocautery machine.This study is a retrospective review of patients who underwent endoscopic intraventricular surgery between January 1, 2018, and September 25, 2019, in which this irrigation system was used. Important components of this system include a bipolar module irrigation regulator that is set to a desired rate, a secure connection of the bipolar irrigation tubing to the endoscope, and one or more open egress ports on the endoscope for passive fluid drainage. Nineteen consecutive patients were identified on review (average age ± SD, 4.3 ± 4.1 years). Procedures performed included third ventriculostomies (n = 10); arachnoid/choroid cyst fenestrations/resections (n = 3); biopsy/tumor resection (n = 1); and combined procedures (n = 5). Foot pedal-controlled irrigation provided visualization of all intraventricular structures. A single operator was able to control the endoscope, endoscopic instruments, and irrigation, with assistance as indicated for more complex maneuvers. There were no perioperative complications. Because this setup is easily constructed from a standard irrigating bipolar machine, delivers precise irrigation flow rates, and facilitates a single-surgeon bimanual technique, these data support the utility of foot-controlled irrigation for endoscopic intraventricular surgery.

근단 협착부 직경, 세척액 주입속도, 주사침 말단의 형상이 치근단에 작용하는 압력에 미치는 영향

본 연구에서는 근관 세척 시 근단 협착부 직경, 세척액 주입속도, 주사침 말단의 형상이 치근단 압력에 미치는 영향을 평가하고자 하였다. 5개의 발치된 사람 하악 소구치에 근관 와동 형성 후 치근단공으로부터 1 mm 짧은 지점을 근단 협착부로 정하고, #35 (0.06 taper) 니켈-티타늄 회전식 기구까지 근관을 형성하였다. 주사침 말단의 형상에 따라 구분되는 notched, side-vented, flat 3가지 종류의 주사침을 근단 협착부로부터 3 mm 거리에 위치시켰고, 세척액 주입속도는 0.05, 0.1, 0.2, 0.3 mL/s로 변화시키며 치근단 압력을 측정하였다. 근단 협착부 직경을 #40, 45 (0.06 taper) 회전식 기구로 확대 후 앞서 언급한 측정과정을 각각 반복하였다. 나머지 조건이 동일한 경우 근단 협착부 직경이 감소할수록, 세척액 주입속도가 증가할수록 치근단 압력은 증가하였으며, flat 주사침이 가장 높은 치근단 압력을 보였고, notched, side-vented 주사침 순서로 치근단 압력이 유의하게 감소하였다(p0.05). 세척액 주입속도가 0.05 mL/s인 군에서는 나머지 조건에 관계없이 모든 경우에서 중심정맥압(5.88 mmHg)보다 낮은 치근단 압력을 나타냈다. 근단 협착부 직경이 0.35 mm일 때, flat needle의 경우 0.05 mL/s의 속도로 세척액 주입 시 AP가 중심정맥압과 유사하므로 사용이 추천되지 않는다. 근단 협착부 직경이 0.35 mm보다 커지면 근단부의 세척액 교환 효과를 높이기 위해 0.05 mL/s의 세척액 주입속도로 notched, flat과 같은 말단 개방형 주사침을 사용할 수 있다.

Avoiding a Lemon: Performance Consistency of Single-Use Ureteroscopes

Single-use flexible ureteroscopes are increasingly popular because of high repair costs of reusable ureteroscopes. As new single-use ureteroscopes enter the market, the consistency of performance of these devices has been questioned. Our objective was to compare two single-use ureteroscopes: the Pusen PU3022a (Zhuhai Pusen) and the LithoVue (Boston Scientific) with emphasis on physical and optical performance consistency. Ten LithoVue and 10 Pusen ureteroscopes were evaluated in never-used condition. The following parameters were recorded: maximal tip deflection with an empty working channel, 200 μm laser fiber, and 1.9F basket; image resolution at 10, 20, and 50 mm; and irrigation flow rate; all ureteroscopes were then fully deflected for 200 cycles. Maximum deflection was remeasured. Mean values for each parameter were compared. To examine within-manufacturer consistency, the variance was calculated and an F-test performed to evaluate for equivalence. Both ureteroscopes provided max deflection over 270°. The Pusen flexed to a greater degree than LithoVue. The Pusen lost more deflection with a laser fiber in the working channel. LithoVue had higher resolution at 10 mm, but the ureteroscopes were similar at 20 and 50 mm. Although the working channel diameter is identical, irrigation flow was higher with the Pusen. However, its working channel was 7 cm shorter than LithoVue. After 200 cycles of deflections, LithoVue had less deflection loss, although one ureteroscope was excluded from analysis because of mechanical failure. Variability was minimal and not significant between manufacturers at all measured parameters. LithoVue and the newer PU3022a have similar "out-of-the-box" performance characteristics and seem durable. These two single-use flexible ureteroscopes performed consistently regardless of the manufacturer.

Temperature changes associated with bone drilling in an orbital model: comparison of ultrasonic bone curette and conventional high-speed rotational drill

ABSTRACTPurpose: Thermal injury to the optic nerve is a potential complication of bony decompression of the orbital apex. An animal model was used to compare and contrast temperature change while removing orbital bone with ultrasonic and conventional drills.Methods: Two devices, Sonopet ultrasonic bone curette and TPS CORE Micro drill, were used to remove bone from six unpreserved exenterated porcine orbits at fixed distances from the optic canal while temperature was recorded. Increasing irrigation flow rate and decreasing saline temperature with the ultrasonic bone curette were also investigated.Results: The mean change in temperature at the optic canal using the ultrasonic bone curette with 18 ml/min 24°C irrigation was +7.2 ± 3.3°C (range 3.3–12.7°C) at 60 s, and using the rotational drill was +1.7 ± 1.3°C (range 0.1–3.3°C), representing a statistically significant increase above baseline for both drills (p < 0.01 for each). The difference in temperature change between drills was statistically significant (p < 0.01). When irrigation fluid was changed from room temperature saline (24°C), rate 18 ml/min to chilled (10°C) irrigation saline, rate 40 ml/min, the magnitude of the mean temperature increase was reduced by 3.1°C, p < 0.05.Conclusions: In this orbital decompression model, both ultrasonic and rotational drills induced a rise in temperature. This increase was significantly greater with the ultrasonic bone curette, measuring up to 13.7°C. Clinicians should be aware of the potential for temperature spikes when decompressing the orbital apex. Increasing irrigation flow rate and using chilled saline may mitigate increases in temperature.

주사침 말단의 형상과 위치, 세척액 주입속도가 치근단에 작용하는 압력에 미치는 영향

본 연구에서는 근관 내의 주사침 말단의 위치, 근관 세척액의 주입 속도, 주사침 말단의 형상이 근관 세척 시 발생하는 치근단 압력에 미치는 영향을 평가하고자 하였다. 5개의 사람 하악 소구치에 근관 와동 형성 후 #35(0.06 taper) 니켈-티타늄 회전식 기구로 근관을 형성하였다. 주사침 말단의 형상에 따라 구분되는 notched, side-vented, flat 3가지 종류의 주사침을 근단 협착부로부터 치관 방향으로 1, 3, 5 mm 거리가 되는 지점(주사침 말단의 위치)에 위치시켰다. 각 군에 대하여 세척액 주입 속도는 0.05, 0.1, 0.2, 0.3 ml/s로 변화시키면서 치근단 압력을 측정하였다. 나머지 조건이 동일한 경우 주사침 말단의 위치가 감소할수록, 세척액 주입 속도가 증가할수록 치근단 압력은 유의하게 증가하였다(p0.05). 주사침 말단의 위치와 세척액 주입 속도가 동일한 조건 하에서 side-vented 주사침이 가장 낮은 치근단 압력을 보였고, notched, flat 주사침 순서로 치근단 압력이 유의하게 증가하였다(p0.05). 주사침 말단의 위치가 1 mm인 군 또는 세척액 주입 속도가 0.1 ml/s 이상인 군에서는 나머지 조건에 관계없이 모든 경우에서 중심정맥압 (5.88mmHg)보다 높은 치근단 압력을 나타냈다. Flat 주사침은 세척액 주입 속도와 주사침 말단의 위치에 따른 치근단 압력의 급격한 증가로 인해 임상에서 사용이 추천되지 않으며, 안전하고 효율적인 근관 세척을 수행하기 위해서는 근단 협착부로부터 치관 방향으로 3 mm 떨어진 지점에 주사침 말단을 위치시키고 0.05 ml/s 이하의 세척액 주입 속도로 근관 세척액을 적용해야 할 것이다.

High-power, low-flow, short-ablation duration-the key to avoid collateral injury?

A common approach to ablating along the posterior wall of the left atrium in atrial fibrillation ablation is to use low power with longer duration for durable lesions and reducing thermal injury. We hypothesize that similar lesions can be safely obtained at high power with low open-irrigation flow and low duration. Twenty-two porcine ventricles were placed in a tissue bath with circulating 0.45% NaCl at a maintained temperature of 37°C. Bipolar radiofrequency ablation (RFA) with a 4-mm-tip irrigated, force-sensing catheter was performed with various combinations of irrigation, power, and duration at 20g of contact force. Fiber optic temperature probes were placed at depths of 3mm and 5mm. Temperature was measured during and 30s after each ablation. Two hundred sixty-eight lesions were made. At a fixed power and flow rate, lesion surface diameter, maximum lesion width, and lesion depth all increased with longer ablation duration. At fixed duration and irrigation flow rate, increased power led to increased lesion dimensions. At a lower flow rate (2ml/min), surface lesion diameter and maximum width were significantly larger compared to a higher flow rate (17ml/min), but lesion depth was not significantly different. The maximum temperature and the rate of temperature rise at a depth of 5mm with different power settings and ablation durations were lower as compared to a depth of 3mm at both flow rates (2ml/min and 17ml/min). Effective lesions can be performed with high-power and short-ablation durations, thereby reducing RFA procedure time. Higher power, shorter duration lesions result in adequate temperature for myocardial lesion formation at 3mm, but do not result in excessive temperature at 5mm depth, potentially reducing the risk of collateral injury. Compared to higher irrigation flow rate, larger surface lesions and comparable maximum lesion width are achieved with lower irrigation flow rate, thus resulting in better lesion contiguity.

Cryobiopsy in the Upper Urinary Tract: Preclinical Evaluation of a Novel Device

ObjectiveTo develop a novel device for cryobiopsy of the upper urinary tract (UUT) and to evaluate its feasibility in a standardized preclinical setting. Materials and MethodsFlexible cryoprobes (diameter 0.9 mm; cooling agent CO2) were developed and used to extract biopsies in porcine UUTs. Cryosamples obtained by ureterorenoscopy were systematically compared with biopsy specimens obtained with standard of care devices in terms of physical characteristics (deflection angle and irrigation flow rates) and histologic criteria (assessability). ResultsIrrigation flow rates were significantly higher with introduced BIGopsy (2.8 ± 0.1) compared with standard forceps (0.94 ± 0.06; P < .001) and cryoprobe (1.1 ± 0.1; P < .001). Angular deflection was significantly reduced by the inserted cryoprobe (130.7° ± 1.2° vs 166.9° ± 1.1° [BIGopsy] or 161.4° ± 1.9° [standard forceps]; both P < .001). Significantly larger UUT tissue samples were obtained by the cryoprobe (mean specimen area 7.5 ± 2.5 vs 4.6 ± 2.5 mm² [BIGopsy] or 1.4 ± 1.4 mm² [standard forceps]; both P < .001). No crush artifacts were observed in cryosamples. Superior histologic assessability scores were achieved in samples obtained by the cryoprobe (mean 2.8 ± 0.8) and BIGopsy (2.3 ± 1.9) when compared with standard forceps (0.4 ± 0.9; P < .001). ConclusionCryobiopsy in the UUT is feasible and represents a viable new option to improve the diagnostic accuracy of histopathologic evaluation. Larger and more representative tissue samples can be obtained using a cryoprobe and artifacts may be avoided. Further optimization of the probe will reduce possible restrictions of ureterorenoscopy handling when the device is inserted.

Effect of simulated intraosseous sinusoidal pressure on NaOCl extrusion

IntroductionThe present study examined the effects of irrigant flow rate and simulated intraosseous sinusoidal pressure on the rate of NaOCl extrusion from the apical terminus of a faux root canal. MethodsAn extrusion setup was designed to enable irrigant extrusion to be opposed by 30 mm Hg simulated intraosseous pressure. The faux canal apex was opposed by atmospheric + 30 mm Hg pressure (experimental) or atmospheric pressure only (control group). Using five irrigant delivery rates (15.6 8.0, 4.0, 3.4 or 3.0 mL/min), the extrusion rates of 2% NaOCl from the faux apex were measured in both groups (n = 16). Data were analysed with two-factor ANOVA and pairwise comparisons at α = 0.05. Correlation between NaOCl delivery rates and extrusion rates in both groups were analysed with the Pearson product-moment procedure. ResultIrrespective of the presence or absence of simulated sinusoidal pressure, NaOCl extrusion rates were positively-correlated with irrigant flow rates. For the factor “irrigant flow rates”, significant differences in NaOCl extrusion rates were identified among all flow rates (p < 0.05), except for the pairwise comparison between 4.0 and 3.4 mL/min in the control. For all irrigant flow rates, NaOCl extrusion rate was significantly lower in the presence of 30 mm Hg simulated sinusoidal pressure than that obtained in the absence of opposing pressure (p < 0.05). ConclusionIn the presence of 30 mm Hg simulated intraosseous pressure, NaOCl delivered via a side-vented needle inserted to 1 mm short of working length may be prevented from extrusion when its flow rate is ≤ 3.0 mL/min. Clinical SignificanceWhen opposed by intraosseous sinusoidal pressure, NaOCl delivered via a side-vented needle inserted to 1 mm short of working length may be prevented from extrusion when its flow rate is ≤ 3.0 mL/min.

Developing an optimization model in drip fertigation management to consider environmental issues and supply plant requirements

Recently, groundwater contamination has increased due to incorrect use of nitrogen fertilizers so that it has caused public concern. To solve the problem, the most appropriate approach is to manage on-time and correct application of water and fertilizer. The objective of this study was to provide an optimization program of drip irrigation and fertigation to maximize the nutrients uptake by plants and minimize water and solute losses in field by optimizing the design and management parameters of drip fertigation. In this research, the HYDRUS (2D/3D) model was used to simulate water and nitrogen transport in soil. For this purpose, the requirement data for calibration and validation of the model were collected by carrying out corn field experiments and performing drip irrigation and fertigation. Then, the calibrated model was used to simulate water and nitrogen behavior in soil and optimization process. To optimize the design and management parameters of fertigation, a two-stage optimization program was considered. In the first stage, the amount of irrigation flow rate, duration of fertilizer injection, and the start time of the injection were simultaneously optimized with the aim of minimizing nitrate leaching in a fertigation cycle. The results showed that by selecting the irrigation rate of 0.8 L h−1 and minimum duration of fertigation at the end of irrigation, nitrate leaching was minimum in the period of fertigation. In the second stage, the amount of fertilizer injection at each stage of fertigation was optimized throughout the growth season using the optimum values of the previous step. In fact, in addition to supplying nitrogen requirement of the plant, the amount of nitrate leaching and its accumulation at the end of each fertigation, especially at the end of the growing season, were also minimized to prevent leaching by post-harvest rainfall.

PD35-04 DANGEROUS TEMPERATURES CAN BE GENERATED DURING URETEROSCOPIC HOLMIUM LASER LITHOTRIPSY, AN IN VITRO ASSESSMENT

You have accessJournal of UrologyStone Disease: Surgical Therapy I1 Apr 2018PD35-04 DANGEROUS TEMPERATURES CAN BE GENERATED DURING URETEROSCOPIC HOLMIUM LASER LITHOTRIPSY, AN IN VITRO ASSESSMENT Daniel Wollin, Evan Carlos, Brenton Winship, Westin Tom, W. Neal Simmons, Glenn Preminger, and Michael Lipkin Daniel WollinDaniel Wollin More articles by this author , Evan CarlosEvan Carlos More articles by this author , Brenton WinshipBrenton Winship More articles by this author , Westin TomWestin Tom More articles by this author , W. Neal SimmonsW. Neal Simmons More articles by this author , Glenn PremingerGlenn Preminger More articles by this author , and Michael LipkinMichael Lipkin More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2018.02.1715AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Ureteroscopic laser lithotripsy requires irrigation for adequate visualization and temperature control during treatment of ureteral stones. However, there is little data on how different irrigation and laser settings affect the ureteral wall and surrounding tissues. This becomes especially important given that exponential thermal cytotoxicity has been shown at temperatures over 43°C. We evaluated the effect of laser settings and irrigation flow on ureteral temperature in an in vitro setting. METHODS To mimic ureteroscopic laser lithotripsy, we simulated clinically relevant irrigation flow rates and fired a holmium laser within saline irrigation tubing. The probe tip of a thermometer was placed 1mm from the tip of a 200μm laser fiber, which was fired for 60 seconds at 0.2J/50Hz, 0.6J/6Hz, 0.8J/8Hz, 1J/10Hz and 1J/20Hz at specified room-temperature flow rates (100cc/min, 50cc/min, 0cc/min). We recorded temperatures every 5 seconds. The overall maximum temperature was noted and each laser/flow trial was duplicated. Maximum temperatures for each trial were compared using ANOVA across irrigation settings. RESULTS At 100cc/min, only the 1J/20Hz laser setting produced a statistically significant higher maximum temperature (p < 0.01), although this was not clinically significant (Tmax 30.7°C). At a lower irrigation rate of 50cc/min, the 1J/20Hz setting was again the only significantly higher maximum temperature (p < 0.05) with a Tmax of 43.4°C. With no flow, all maximum temperatures reached over 43°C, with 0.8J/8Hz, 1J/10Hz, and 1J/20Hz each statistically higher than the lower-energy settings (p < 0.05). 43°C was achieved within 15 seconds of laser firing at the 1J/20Hz, 1J/10Hz, 0.8J/8Hz, and 0.6J/6Hz settings. Additionally, with no irrigation 1J/20Hz eclipsed 43°C within 5 seconds and reached ≥100°C causing us to halt its trials 10 seconds early (Figure). CONCLUSIONS Despite increasing laser power settings, adequate irrigation can maintain relatively stable temperatures within an in vitro ureteral system. As irrigation rates decrease, even lower laser power settings achieve potential harmful temperatures in a matter of seconds. © 2018FiguresReferencesRelatedDetails Volume 199Issue 4SApril 2018Page: e722 Advertisement Copyright & Permissions© 2018MetricsAuthor Information Daniel Wollin More articles by this author Evan Carlos More articles by this author Brenton Winship More articles by this author Westin Tom More articles by this author W. Neal Simmons More articles by this author Glenn Preminger More articles by this author Michael Lipkin More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Thermal Response to High-Power Holmium Laser Lithotripsy.

The aim of this study was to investigate "caliceal" fluid temperature changes during holmium laser activation/lithotripsy using settings up to 40 W power output with different irrigation flow rates. The experimental system consisted of a glass test tube (diameter 10 mm/length 75 mm) filled with deionized water, to mimic a calix. Real-time temperature was recorded using a thermocouple (Physitemp, NJ) positioned 5 mm from the bottom of the tube. A 200 μm laser fiber (Flexiva; Boston Scientific, MA) was introduced through the working channel of a disposable ureteroscope (LithoVue; Boston Scientific) and the laser fiber tip was positioned 15 mm above the bottom of the test tube. Deionized water irrigation (room temperature) through the working channel of the ureteroscope was delivered at flow rates of 0, 7-8, 14-15, and 38-40 mL/minute. A 120-W holmium laser (pulse 120; Lumenis, CA) was used. The following settings were explored: 0.5 J × 10 Hz, 1.0 J × 10 Hz, 0.5 J × 20 Hz, 1.0 J × 20 Hz, 0.5 J × 40 Hz, 1.0 J × 40 Hz, and 0.5 J × 80 Hz. During each experiment, the laser was activated continuously for 60 seconds. Temperature increased with increasing laser power output and decreasing irrigation flow rate. The highest temperature, 70.3°C (standard deviation 2.7), occurred with laser setting of 1.0 J × 40 Hz and no irrigation after 60 seconds of continuous laser firing. None of the tested laser settings and irrigation parameters produced temperature exceeding 51°C when activated for only 10 seconds of continuous laser firing. High-power holmium settings fired in long bursts with low irrigation flow rates can generate high fluid temperatures in a laboratory "caliceal" model. Awareness of this risk allows urologist to implement a variety of techniques (higher irrigation flow rates, intermittent laser activation, and potentially cooled irrigation fluid) to control and mitigate thermal effects during holmium laser lithotripsy.

Effect of Laser Settings and Irrigation Rates on Ureteral Temperature During Holmium Laser Lithotripsy, an In Vitro Model.

Ureteroscopic laser lithotripsy requires irrigation for adequate visualization and temperature control during treatment of ureteral stones. However, there are little data on how different irrigation and laser settings affect the ureteral wall and surrounding tissues. This effect has become an important consideration with the advent of high-powered lasers. We therefore evaluated the effect of laser settings and irrigation flow on ureteral temperature in an in vitro setting. To mimic ureteroscopic laser lithotripsy, we simulated clinically relevant irrigation flow rates and fired a Holmium:Yttrium-aluminum-garnet (Ho:YAG) laser while monitoring "intraureteral" temperature. The probe tip of a thermometer was placed 1 mm from the tip of a 200 μm laser fiber, which was fired for 60 seconds at 0.2 J/50 Hz, 0.6 J/6 Hz, 0.8 J/8 Hz, 1 J/10 Hz, and 1 J/20 Hz within a tubing system that allowed for specified room temperature flow rates (100, 50, and 0 mL/minute). We recorded temperatures every 5 seconds. The maximum temperature was noted, and each laser/flow trial was duplicated. Averaged maximum temperatures were compared using analysis of variance across irrigation settings. At 100 cc/minute, only the 1 J/20 Hz laser setting produced a significantly higher maximum temperature (p < 0.01), although this finding was not clinically significant at a maximum of 30.7°C. At a lower irrigation rate of 50 cc/minute, the 1 J/20 Hz setting was again the only significantly higher maximum temperature (p < 0.05), although this temperature crossed the toxic threshold at a maximum of 43.4°C. With no flow, all maximum temperatures reached over 43°C, with 0.8 J/8 Hz, 1 J/10 Hz, and 1 J/20 Hz each statistically higher than the lower-energy settings (p < 0.05). The maximum temperature at 1 J/20 Hz with no irrigation was over 100°C. Despite increasing laser settings, adequate irrigation can maintain relatively stable temperatures within an in vitro ureteral system. As irrigation rates decrease, even lower power laser settings produce a clinically significant increase in maximum temperature, potentially causing ureteral tissue injury.

Impact of Lowering Irrigation Flow RateonAtrial Lesion Formation in ThinAtrialTissue: Preliminary Observations From Experimental and ClinicalStudies.

The authors sought to investigate the effect of low irrigation flow rate on lesion characteristics and ablation outcomes in a clinicopathological study. Irrigated ablation produces deeper lesions compared with nonirrigated ablation, which may not be desirable in the thin-walled posterior left atrium (LA), where collateral esophageal injury is possible. Lesions were placed on the smooth posterior right atrium in 20 swine and posterior LA in 60 patients at a maximum power of 20 to 25 W with either: 1) power-controlled ablation at an irrigation flow rate of 17 ml/min (high-flow group 10 swine; n = 40) or 2) temperature-controlled ablation at an irrigation flow rate of 2 ml/min (low-flow group10 swine; n = 20). Safety and efficacy was also compared in 326 patients undergoing AF ablation using high-flow (n= 160) or low-flow settings (n= 166) for posterior LA ablation. Low-flow, compared with high-flow, lesions in swine had a higher incidence of lesions with: impedance fall≥10 Ω, loss of pace capture, electrograms characteristic of transmural lesions, and visible lesions on anatomic inspection (p< 0.05 for all). Low-flow lesions had a maximal diameter at the endocardial surface, whereas high-flow lesions had a maximal diameter at the epicardial surface. In humans, impedance, pace capture, and transmurality dataalso strongly favored low-flow lesions. There was no difference in acute pulmonary vein isolation, complications, or12-month arrhythmia-free survival between the groups. Low-flow irrigated ablation provides favorable lesion characteristics for posterior LA ablation withoutincreasing the risk of adverse events.

Transport of oxytetracycline, chlortetracycline, and ivermectin in surface runoff from irrigated pasture

ABSTRACTThe transport of oxytetracycline, chlortetracycline, and ivermectin from manure was assessed via surface runoff on irrigated pasture. Surface runoff plots in the Sierra Foothills of Northern California were used to evaluate the effects of irrigation water application rates, pharmaceutical application conditions, vegetative cover, and vegetative filter strip length on the pharmaceutical discharge in surface runoff. Experiments were designed to permit the maximum potential transport of pharmaceuticals to surface runoff water, which included pre-irrigation to saturate soil, trimming grass where manure was applied, and laying a continuous manure strip perpendicular to the flow of water. However, due to high sorption of the pharmaceuticals to manure and soil, less than 0.1% of applied pharmaceuticals were detected in runoff water. Results demonstrated an increase of pharmaceutical transport in surface runoff with increased pharmaceutical concentration in manure, the concentration of pharmaceuticals in runoff water remained constant with increased irrigation flow rate, and no appreciable decrease in pharmaceutical runoff was produced with the vegetative filter strip length increased from 30.5 to 91.5 cm. Most of the applied pharmaceuticals were retained in the manure or within the upper 5 cm of soil directly beneath the manure application sites. As this study evaluated conditions for high transport potential, the data suggest that the risk for significant chlortetracycline, oxytetracycline, and ivermectin transport to surface water from cattle manure on irrigated pasture is low.

Effect of Canal Anastomosis on Periapical Fluid Pressure Build-up during Needle Irrigation in Single Roots with Double Canals using a Polycarbonate Model

Sodium hypochlorite is an effective irrigant for chemical debridement of root canals. However, increasing the intracanal pressure during irrigant delivery may result in irrigant extrusion into the bone and soft tissues surrounding the tooth. Because clinicians often encounter teeth with intracanal communications, the objective of the present study was to examine the effects of canal anastomosis on the generation of periapical fluid pressure at different fluid flow rates and insertion depths. Two similar polycarbonate models were used to simulate a single root with double canals, one containing, and the other without communicating channels between the canals. For both models, periapical pressure increased with increasing irrigant flow rates and insertion depths of a 30-gauge side-venting needle. In the presence of communicating channels, the magnitude of pressure build-up decreased by almost 90% irrespective of the fluid flow rate or needle insertion depth. Pressure reduction in anastomoses-containing roots provides an explanation why pressure generation in single roots is considerably higher. Nevertheless, it is still possible in teeth with canal anastomoses for pressure exceeding the intraosseous pressure to be generated when the fluid flow rate is sufficiently high and when the needle tip is close to the apical terminus.

MP50-19 INTRA-RENAL PRESSURES DURING RA-RIRS (ROBOTIC ASSISTED RETROGRADE INTRA-RENAL SURGERY): A CRITICAL EVALUATION BASED ON URETERAL ACCESS SHEATH (UAS) SIZE AND IRRIGATION FLOW RATE

You have accessJournal of UrologyStone Disease: Surgical Therapy V1 Apr 2017MP50-19 INTRA-RENAL PRESSURES DURING RA-RIRS (ROBOTIC ASSISTED RETROGRADE INTRA-RENAL SURGERY): A CRITICAL EVALUATION BASED ON URETERAL ACCESS SHEATH (UAS) SIZE AND IRRIGATION FLOW RATE Nida Zafer Tokatli, Kemal Sarica, Ahmet Sinan Kabakci, Remzi Saglam, and Anup Patel Nida Zafer TokatliNida Zafer Tokatli More articles by this author , Kemal SaricaKemal Sarica More articles by this author , Ahmet Sinan KabakciAhmet Sinan Kabakci More articles by this author , Remzi SaglamRemzi Saglam More articles by this author , and Anup PatelAnup Patel More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2017.02.1607AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES To evaluate effects of varying UAS sizes (10/12F - 12/14F) and changing irrigation flow rates modulated by custom designed pump system, on RA-RIRS intra-renal pressure levels. METHODS To evaluate changing irrigation flow rate effects on intra-renal pressure values during RA-RIRS, a customized pump system adjusted for stepwise flow rate increases between 5-60 ml/min, was connected to two different flexible uretero-renoscopes (FlexX2 and FlexXC, Karl Storz GmbH, Germany) coupled to the Avicenna Roboflex. Free channel flow rates through each instrument working channel were measured several times for a set irrigant height. After assessing baseline flow rates with constant flow, the study was repeated using a custom designed pump system (ELMED, Turkey). RA-RIRS intrarenal pressures were measured percutaneously using 4 different manufacturer's access sheaths positioned in the proximal ureter (9.5/11.5F Cook, 10/12F Rocamed, 10.7/12.7F Cook and 12/14F Boston Scientific). Studies were repeated subsequently in the Minnesota University kidney model with calyceal puncture, as with patients. RESULTS Smaller sized UAS ( 9.5/11.5F) limited irrigant efflux along the outer side and resulted in increased intrarenal pressures in a short time even without a pump system. For larger UAS sizes, intrarenal pressures continued to remain <30cmH2O even with irrigation rates of up to 20ml/min. Lastly, when 12/14F UAS was used, intrarenal pressures were < 30cmH2O despite irrigation flow rates up to 60ml/min. CONCLUSIONS Using an appropriate sized UAS during RA-RIRS is of paramount importance. Careful irrigant flow rate adjustment with precisely controlled intrarenal pressure values, preferably using a specially designed pump system, can enable surgeons to perform RA-RIRS safely with clear vision with larger UAS sizes. This approach may increase stone free rates, and reduce pressure build-up plus infection-related complication risk, particularly in cases with large and complex stones needing longer operating times. © 2017FiguresReferencesRelatedDetails Volume 197Issue 4SApril 2017Page: e691 Advertisement Copyright & Permissions© 2017MetricsAuthor Information Nida Zafer Tokatli More articles by this author Kemal Sarica More articles by this author Ahmet Sinan Kabakci More articles by this author Remzi Saglam More articles by this author Anup Patel More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Subacromial temperature profile during bipolar radiofrequency use in shoulder arthroscopy. Comparison of Coblation® vs. VAPR®

BackgroundThe use of bipolar electrodes for arthroscopic procedures carries a theoretical ex vivo risk of inducing burn injuries. Few studies have measured the in vivo temperatures produced by bipolar electrodes during arthroscopy, and their results are conflicting. The objective of this study was to evaluate the temperature profile within the subacromial space during shoulder arthroscopy with two different electrode systems. HypothesisThe primary hypothesis was that the two electrode systems produced similar temperature variations and peak temperatures. The secondary hypothesis was that neither electrode system produced irrigation-fluid temperatures above the tissue-damage threshold. Material and methodsA comparative, prospective, single-centre, single-surgeon, single-blind study was conducted to compare the Coblation® system (Smith&Nephew, Andover, MA, USA) and the VAPR® system (DePuy Synthes Mitek Sports Medicine, Raynham, MA, USA) in 13 patients undergoing shoulder arthroscopy. A temperature probe inserted into the subacromial space was used to record temperatures at 10-second intervals for 60seconds during continuous radiofrequency application. ResultsMean baseline temperature was 21.4±0.7°C with VAPR® and 23.0±2.2°C with Coblation®. No significant between-group differences were found during the first 40seconds. The mean peak temperature reached after 60seconds was 25.0±1.9°C with VAPR® and 27.9±2.8°C with Coblation® (P<0.05). DiscussionFew studies have compared the in vivo temperatures produced during arthroscopy by different electrode systems. In vivo studies have established that temperature increases can cause tissue damage, particularly to chondrocytes, and that the irrigation flow rate plays a key role in lowering the in vivo temperatures. Our study showed a significant difference between the two electrode systems after 50seconds of use, with lower temperatures with the VAPR®. Nevertheless, neither system increased the irrigation-fluid temperatures above the tissue-damage threshold. Both systems can be used safely, provided the manufacturer instructions are followed and the irrigation system is effective. Level of evidenceII (prospective randomized trial).

Investigation of Affecting Parameters on Heap Leaching Performance and Reducing Acid Consumption of Low Grade Oxide-Sulfide Copper Ore

Heap leaching method is known as cheap method for copper extraction. Presence of clay and acid consumer waste minerals are the most critical issues because they may bring out the process from economic mode. For reduce acid consumption and increasing copper extraction in heap leaching method, about 3 tons sample was taken randomly from different low grade zones. After homogenization and spelling into small parts, bottle roll tests were carried out to achieve maximum copper recovery and acid consumption in a short time at pH= 1, 1.1 and 1.2. Maximum copper recovery were 60.8, 60.2 and 60.1%, respectively. Also acid consumption were 107.30, 99.90 and 93.23 kg/t of ore, respectively. After diagnostic tests, nine columns with dimension 2m height and 15cm diameter were filled by 0.5, 1 and 1.5 inches ore. Columns were irrigated with 7, 9 and 11 g/l as acid solution concentration at flow rates of 7, 11 and 15 l/m2*h for 63 days. Results showed that there are high correlation between copper and iron recoveries. Copper recovery changed from 25.5% to 58.9% while iron recovery changed from 4.7% to 15.2%. Acid consumption were achieved between 18 to 54 kg per ton of ore. Acid solution concentration and irrigation flow rate are the most important parameters on the copper and iron recoveries. By increasing of leaching period Copper extraction will increase, but acid will be waste more. Copper and iron recoveries were increased with increasing the acid solution concentration and irrigation flow rate but Increasing in amount of acid consumption does not increase copper extraction inevitably. Irrigation flow rate of acid solution has significant effect on acid consumption. With decreasing the ore particle size, both of copper recovery and acid consumption were increased.

A comparative assessment of irrigation and drainage characteristics for commercially available urethral catheters

IntroductionWe aimed to investigate irrigation and drainage characteristics of commercially available urethral catheters and determined which catheter offers the best flow characteristics.Material and methodsTwelve different commercially available urethral catheters from three companies (Bard™, Rusch™ and Dover™) were investigated to compare their irrigation and drainage properties. Irrigation port, drainage port and overall cross-sectional areas for a 24Fr 3-way catheter was measured and compared. The maximum (Qmax) and average (Qavg) irrigation and drainage flow rates for each catheter was measured for 20–40 seconds using uroflowmetry. The primary endpoint was to determine which catheter offers optimal irrigation and drainage parameters.ResultsOverall cross-sectional area, irrigation port cross-sectional area, and drainage port cross-sectional area differed significantly for each 24Fr 3-way catheter assessed (p <0.001). The 24Fr 3-way Rusch Simplastic™ catheter consistently demonstrated the greatest maximal flow rate (Qmax: 5 ±0.3 ml/s) and average flow rate (Qavg: 4.6 ±0.2 ml/s) for irrigation. The 24Fr 3-way Dover™ catheter provided the greatest drainage properties (Qmax: 19.7 ±2 ml/s; Q avg: 15.9 ±5 ml/s). In the setting of continuous bladder irrigation, the 24Fr 3-way Rusch Simplastic™ catheter provided the highest irrigation rates (Qmax: 6.6 ±1.8 ml/s; Q avg: 4.6 ±0.9 ml/s).ConclusionsThree-way catheters demonstrate significant differences in their irrigation and drainage characteristics. The type of catheter selected should be based on the appropriate prioritization of efficient bladder irrigation versus efficient bladder drainage.

Determining the Optimum Decision Variables and Rescheduling the Irrigation System of Tendaho Sugar Estate, Ethiopia

Irrigation scheduling, flow rate and cut-off time are the three field irrigation variables currently affecting irrigation performance of Tendaho Sugar estate (Northeast of Ethiopia). As result, the study was initiated with the objective of improving existing irrigation scheduling and determining significant decision variables (flow rate and cut-off time). The long year’s climatic data were collected and analyzed by CROPWAT8.0 software to calculation of the right amount of water needed for the irrigation of crop fields, and soil samples were collected from representative cane fields to analyze soil characteristics. Parshall flumes were used to measure inflow rates at each field. The results of irrigation scheduling have showed slighter irrigation intervals than existing intervals. Therefore, to improvement of irrigation scheduling have proposed based on soil, crop ages and climatic casus of the area. Besides, the inflow rate and cut-off time of two major soils of study area were proposed to be 5 liters per second and 45 minute for 100 meter length of furrows as best decision variables of the sugar estate. Finally, the author trusts the right combination of these critical variables will help the sugar estate to overcome its existing irrigation problems, and result in better field water application and field conditions.