NCT03023488

Effects of Flexible Ureteroscopy on Renal Blood Flow

Effects Of Flexible Ureteroscopy On Renal Blood Flow

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 46 (actual)
• Sponsor: Marmara University · Academic / Other
• Sex: All
• Age: 18 Years – 65 Years
• Healthy volunteers: Not accepted

Summary

Aim of this study is to investigate the effects of increased intrarenal pressure during flexible ureteroscopy on renal blood flow. Patients undergoing flexible ureteroscopy (F-URS) and laser lithotripsy for kidney stones according to European Association of Urology (EAU) guidelines on Urolithiasis will be included in the study after having signed an informed consent form. The pre- and post-operative evaluation and management will be performed according to EAU Guidelines on Urolithiasis. Additionally, as a non-invasive test, bilateral renal power Doppler US will be performed to patients pre- and post-operatively. The pre-operative Doppler US will be performed 2 days prior to surgery and the post-operative Doppler US will be performed in the first 24 hours following surgery. The changes on blood flow in renal artery and arcuate artery will be recorded.

Detailed description

Aim of this study is to investigate the effects of increased intrarenal pressure during flexible ureteroscopy on renal blood flow. Patients undergoing flexible ureteroscopy and laser lithotripsy for kidney stones according to EAU guidelines on Urolithiasis will be included in the study after having signed an informed consent form. The pre- and post-operative evaluation and management will be performed according to EAU Guidelines on Urolithiasis. Additionally, as a non-invasive test, bilateral renal power Doppler US will be performed to patients pre- and post-operatively. The pre-operative Doppler US will be performed 2 days prior to surgery and the post-operative Doppler US will be performed in the first 24 hours following surgery. The changes on blood flow in renal artery and arcuate artery will be recorded. Flexible ureteroscopy has been a key component of kidney stone management in the last 20 years. Even for stones larger than 2 cm, flexible ureteroscopy can be performed with high success and low complication rates. Ureteral access sheaths are key contributors to flexible ureteroscopy as they provide easy and repeated access to upper urinary tract and decreased intrarenal pressures due to easy flow back of the irrigation solution. The increased pressures during flexible ureteroscopy have been an important research area in the last years. Due to irrigation solution and irrigational pumping to provide a clearer vision during flexible ureteroscopy, intrarenal pressures rise and after a certain point pyelo-sinusoidal, pyelo-venous and pyelo-lymphatic backflow starts. It has been shown that this backflow starts when pressure rises above 40 cmH2O (centimeters-water / unit of pressure measurement). Schwalb et al. demonstrated in their study that in kidneys subject to high intrarenal pressure, denudation and flattening of the caliceal urothelium, submucosal edema and congestion are observed. Due to these deleterious effects on urothelium, renal extravasation and bacterial translocation can occur and complications may arise. Renal Doppler US, due to its non-invasive nature, has been widely used to measure localized blood flow in the kidneys, to evaluate hemodynamic parameters in acute kidney injury. Intrarenal backflow and its consequences such as submucosal edema and congestion may decrease blood flow especially around the calyces subject to high pressures and this situation may result in acute kidney injury.

Conditions

• Circulatory; Change

Interventions

Type	Name	Description
PROCEDURE	flexible ureteroscopy	Flexible ureteroscopy is an endourological procedure performed for kidney stones. The flexible ureteroscope is a device used to reach the renal cavities through the natural urinary tract in a retrograde fashion. During the operation, irrigation fluid is used to expand the cavities to provide space for movement of the device and also to provide clear vision.
DEVICE	Doppler Ultrasound examination	peak systolic velocities (PSV) and end diastolic velocities (EDV) of the arteries will be measured and then resistive index (RI) and pulsatility index (PI) will be calculated.
DEVICE	laser lithotripsy	The laser fiber extending into the cavities through the working channel of the ureteroscope is used to fragment the stones. Laser energy is generated by the laser machine and transmitted to the stones via the laser fiber.

Timeline

• Start date: 2016-02-01
• Primary completion: 2016-10-01
• Completion: 2016-12-01
• First posted: 2017-01-18
• Last updated: 2018-07-06
• Results posted: 2017-05-18