Lichen sclerosis–induced long segment anterior urethral stricture: The early outcome of one-stage repair using dorsolateral onlay buccal mucosa graft

2021 ◽  
pp. 039156032110033
Author(s):  
Atef Fathi ◽  
Omar Mohamed ◽  
Osama Mahmoud ◽  
Gamal A Alsagheer ◽  
Ahmed M Reyad ◽  
...  
Keyword(s):  
Success Rate ◽  
Urethral Stricture ◽  
Flow Rate ◽  
Urine Volume ◽  
Maximum Flow ◽  
Maximum Flow Rate ◽  
P Value ◽  
Onlay Graft ◽  
Voiding Symptoms ◽  
Stricture Recurrence

Background: Substitution urethroplasty using buccal mucosal grafts can be performed by several approaches including ventral onlay graft, dorsal onlay graft, or ventral urethrotomy with dorsal inlay graft. Our study aims to evaluate the surgical outcome of dorsolateral buccal mucosal graft for long segment anterior urethral stricture >6 cm in patients with Lichen sclerosus (LS). Methods: A retrospective study included patients who underwent repair for long segment anterior urethral stricture >6 cm due to LS between January 2013 and April 2019. All patients were followed-up at 3, 6, 9, and 12 months postoperatively and then yearly by clinical symptoms, uroflowmetry, and calculation of post-void residual urine volume. Retrograde urethrogram was requested for patients with voiding symptoms or decreased maximum flow rate. Stricture recurrence that required subsequent urethrotomy or urethroplasty was considered failure. The success rate and surgical complications were collected and analyzed. Results: Thirty patients were identified. The median age (range) was 39 (25–61) years and a median (range) stricture length was 8 (6–14) cm. Most of postoperative complications were of minor degree. The success rate at median follow-up of 15 (12–24) months was 86.5%. The median maximum flow rate increased significantly from 6 (2–11) ml/s preoperatively to 18 (range: 6–23) ml/s at the 6th month ( p value < 0.001). Conclusion: Dorsolateral buccal mucosal grafts urethroplasty for long anterior urethral stricture caused by LS has a high success rate and low risk of complications including stricture recurrence.

scholarly journals Management of men with ultra-short penile urethral stricture using augmented anastomotic penile skin flap urethroplasty; a retrospective analysis

2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Abdel W. El-Kassaby ◽  
Mohammed Saber Khalaf ◽  
Ahmed M. Reyad
Keyword(s):  
Success Rate ◽  
Urethral Stricture ◽  
Flow Rate ◽  
Skin Flap ◽  
Maximum Flow ◽  
Maximum Flow Rate ◽  
Control Group ◽  
Study Group ◽  
Significant Difference ◽  
Dorsal Onlay

Abstract Background The management of short anterior urethral stricture is challenging. Our study aims to evaluate the outcome of augmented anastomotic urethroplasty (AAU) for the management of men with ultra-short penile urethral stricture, and to compare it with the dorsal onlay buccal mucosa graft. Methods Databases of two tertiary referral centres were retrospectively reviewed to retrieve data of men with ultra-short penile urethral stricture who underwent urethroplasty from 2013 to 2020. Patients who underwent AAU with ventral onlay pedicled skin flap were considered the study group, while patients treated with the dorsal onlay graft augmentation were included as controls. Surgical outcomes included urethral patency, improvement in the maximum flow rate (Qmax), change in sexual satisfaction, and any reported complications. Results Thirty-four patients (and 30 controls) with a median age of 26–27 years were included in the study. The maximum flow rate improved significantly in both groups compared to the preoperative value (p < 0.001). The success rate was 88% in the study group compared to 76.7% in the control group. There was no statistically significant difference in the frequency of postoperative penile curvature nor the ventral sacculation between the two groups (p = 0.788 and 0.913). The operative time was statistically significantly longer in the control group (p = 0.044), while the frequency of postoperative void dripping was much higher in the study group (p = 0.007). Conclusion The success rate and complications of AAU for men with ultra-short penile urethral stricture were comparable to the dorsal buccal graft.

scholarly journals Evaluation of the Short Term Outcome of Unilateral Urethral Mobilization Compared to Circumferential Urethral Mobilization for the Management of Bulbar Urethral Stricture

2020 ◽  
Vol 19 (1) ◽  
pp. 32-37
Author(s):  
Kartik Chandra Ghosh ◽  
Md Mizanur Rahman ◽  
Md Shafiqul Alam Chowdhury ◽  
Produyt Kumar Saha ◽  
Mohammed Mizanur Rahman ◽  
...  
Keyword(s):  
Urethral Stricture ◽  
Flow Rate ◽  
Buccal Mucosa ◽  
Urine Volume ◽  
Urinary Flow Rate ◽  
P Value ◽  
Urinary Flow ◽  
College Hospital ◽  
Group I ◽  
Group Ii

Objective: To evaluate and compare the outcome of buccal mucosal graft urethroplasty of unilateral and circumferential urethral mobilization for the management of bulbar urethral stricture. Methods: Seventy patients having bulbar urethral strictures admitted in the Department of Urology, Dhaka Medical College Hospital, Dhaka between January 2010 to December 2011. Patients were divided into two groups. Group-I, underwent unilateral urethral mobilization, and Group-II, underwent circumferential urethral mobilization for buccal mucosa graft urethroplasty. All patients were followed up at least six months. The statistics used to analyze the data were descriptive statistics, and p value <0.05 was considered as significant. Results: Mean±SD of age in Group-II and Group-I were 41.1±9.2 and 37.4±8.2 years respectively. All the baseline findings were identically distributed between the groups. Comparison of outcome at month 3 showed that peak urinary flow rate increased from their baseline figures, but the increase was significantly more in the unilateral group than that in the circumferential group (21.2±1.2 vs. 18.9±2.0 Qmax, p =< 0.001). After 6 months, evaluation showed that the peak urinary flow rate significantly higher in Group-I, than that in Group-II, (24.2±2.9 vs. 21.9 ± 3.3, p < 0.001). The voided urine volume was also significantly higher in Group-I, than that in Group-II (330.8±50.1 vs. 294.5±46.1 ml, p = 0.004). Consequently, PVR was lower in the former group than that in the latter group (11.6±3.3 vs. 14.1±2.9 ml, p = 0.002). Complications in unilateral urethral mobilization had a significantly lower (20%) than that of circumferential urethral mobilization(45.71%) (p=0.024). Conclusion: Buccal mucosa grafting is a versatile and effective treatment for the anterior urethral stricture, and the outcome is excellent following unilateral urethral mobilization in experienced hands. Bangladesh Journal of Urology, Vol. 19, No. 1, Jan 2016 p.32-37

Outcome of Buccal Mucosal Graft Urethroplasty in Long Segment Anterior Urethral Stricture

2020 ◽  
Vol 19 (2) ◽  
pp. 64-68
Author(s):  
Mrinmoy Biswas ◽  
Sudip Das Gupta ◽  
Mohammed Mizanur Rahman ◽  
Sharif Mohammad Wasimuddin
Keyword(s):  
Urethral Stricture ◽  
Flow Rate ◽  
Surgical Outcome ◽  
Simple Technique ◽  
Anterior Segment ◽  
Maximum Flow ◽  
Anastomotic Site ◽  
Buccal Mucosal Graft ◽  
Male Patients

Objective: To assess the success of BMG urethroplasty in long segment anterior urethral stricture. Method: From January 2014 to December 2015, twenty male patients with long anterior segment urethral stricture were managed by BMG urethroplasty. After voiding trial they were followed up at 3 month with Uroflowmetry, RGU & MCU and PVR measurement by USG. Patients were further followed up with Uroflowmetry and PVR at 6 months interval.Successful outcome was defined as normal voiding with a maximum flow rate >15ml /sec and PVR<50 ml with consideration of maximum one attempt of OIU after catheter removal. Results: Mean stricture length was 5.2 cm (range 3-9 cm) and mean follow-up was 15.55 months (range 6-23 months). Only two patients developed stricture at proximal anastomotic site during follow-up. One of them voided normally after single attempt of OIU. Other one required second attempt of OIU and was considered as failure (5%). Conclusion: BMG urethroplasty is a simple technique with good surgical outcome. Bangladesh Journal of Urology, Vol. 19, No. 2, July 2016 p.64-68

scholarly journals Maximum Flow Rate of a Single Component, Two-Phase Mixture

1965 ◽  
Vol 87 (1) ◽  
pp. 134-141 ◽  
Author(s):  
F. J. Moody
Keyword(s):  
Flow Rate ◽  
Static Pressure ◽  
Maximum Flow ◽  
Single Component ◽  
Maximum Flow Rate ◽  
Vapor Flow ◽  
Two Phase ◽  
Slip Ratio ◽  
Phase Mixture ◽  
Local Slip

A theoretical model is developed for predicting the maximum flow rate of a single component, two-phase mixture. It is based upon annular flow, uniform linear velocities of each phase, and equilibrium between liquid and vapor. Flow rate is maximized with respect to local slip ratio and static pressure for known stagnation conditions. Graphs are presented giving maximum steam/water flow rates for: local static pressures between 25 and 3,000 psia, with local qualities from 0.01 to 1.00; local stagnation pressures and enthalpies which cover the range of saturation states.

Effect of Blade Angle of Attack and Hub to Tip Ratio on Mass Flow Rate in an Axial Fan at a Fixed Rotational Speed

2008 ◽  
Author(s):  
Mohammad J. Izadi ◽  
Alireza Falahat
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Rotational Speed ◽  
Angle Of Attack ◽  
Maximum Flow ◽  
Maximum Flow Rate ◽  
Maximum Mass ◽  
Blade Angle ◽  
Axial Fan

In this investigation an attempt is made to find the best hub to tip ratio, the maximum number of blades, and the best angle of attack of an axial fan with flat blades at a fixed rotational speed for a maximum mass flow rate in a steady and turbulent conditions. In this study the blade angles are varied from 30 to 70 degrees, the hub to tip ratio is varied from 0.2 to 0.4 and the number of blades are varied from 2 to 6 at a fixed hub rotational speed. The results show that, the maximum flow rate is achieved at a blade angle of attack of about 45 degrees for when the number of blades is set equal to 4 at most rotational velocities. The numerical results show that as the hub to tip ratio is decreased, the mass flow rate is increased. For a hub to tip ratio of 0.2, and an angle of attack around 45 degrees with 4 blades, a maximum mass flow rate is achieved.

The characters exploration of a piezoelectric pump with fishtail-shaped bluffbody

2021 ◽  
pp. 1045389X2110386
Author(s):  
Yi Hou ◽  
Lipeng He ◽  
Zheng Zhang ◽  
Baojun Yu ◽  
Hong Jiang ◽  
...  
Keyword(s):  
Flow Rate ◽  
Preliminary Investigation ◽  
Maximum Flow ◽  
Theoretical Explanation ◽  
Maximum Flow Rate ◽  
Bluff Bodies ◽  
Conical Flow ◽  
Piezoelectric Pump ◽  
Valveless Piezoelectric Pump ◽  
Shape And Size

This paper focuses on a new structure in the valveless piezoelectric pump, which has a combination structure of the conical flow channel and two fishtail-shaped bluffbodies in the chamber of the pump. The fishtail-shaped bluffbody is inspired by the shape of the swimming fish to diminish the backflow and optimize the performance of the pump. The performance is studied by changing the shape and size of the inlet and outlet, the bluff bodies’ height and the space between two bluff bodies. The results show that the 3 mm × 3 mm square inlet, 3 mm diameter round outlet, 3 mm height of bluffbodies, 6.8 mm pitch of bluffbodies has a best performance in all 10 prototypes, which implements a maximum flow rate of 87.5 ml/min at 170 V 40 Hz with a noise of 42.6 dB. This study makes a preliminary investigation and theoretical explanation for the subsequent optimization of this structure, improved the performance of the valveless piezoelectric pump, broaden the thinking of the design for the bluffbody for better performance of the valveless piezoelectric pump.

Transport of Particle-Laden Fluids Through Fixed-Valve Micropumps

1999 ◽  
Author(s):  
Ling-Sheng Jang ◽  
Christopher J. Morris ◽  
Nigel R. Sharma ◽  
Ron L. Bardell ◽  
Fred K. Forster
Keyword(s):  
Surface Charge ◽  
Surface Area ◽  
Flow Rate ◽  
Pure Water ◽  
Maximum Flow ◽  
Total Surface Area ◽  
Maximum Flow Rate ◽  
Number Density ◽  
Polystyrene Microspheres ◽  
Negative Surface

Abstract Micropumps designed for the flow-rate range of 100–1000μl/min have been developed by a number of research groups. However, little data is available regarding the ability of various designs to directly transport liquids containing particles such as cells, microspheres utilized for bead chemistry, or contaminants. In this study the ability of pumps with no-moving-parts valves (NMPV) to transport particles was investigated. The results showed that a NMPV micropump was able to directly pump suspensions of polystyrene microspheres from 3.1 to 20.3μm in diameter. The pump functioned without clogging at microsphere number densities as high as 9000 particles/μl of suspension, which corresponded to over 90,000 particles per second passing through the pump at a flow rate of 600μl/min. Performance with polystyrene microspheres was the same as pure water up to the point of cavitation. Microspheres manufactured with negative surface charge cavitated less readily that other microspheres studied that were manufactured without surface charge. However, cavitation did not appear to be a function of microsphere size, total surface area or number density. Thus pumping polystyrene microspheres was found to be more affected by surface effects than by size, surface area or number density within the range of parameters considered. In the case of charged microspheres, the maximum flow rate was reduced by 30% compared to pure water whereas for uncharged microspheres the maximum flow rate was reduced by approximately 80%.

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