View clinical trials related to Renal Calculi.
Filter by:The aim of the present study to perform a full cost analysis for the complete clearance of calyceal stones by retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PNL) for the treatment of lower calyceal stones between 1 and 2 centimeters (cm) in size.
Prospective randomized controlled single-blind parallel-group trial in order to compare symptoms related to loop-tail (Polaris Loop) stents versus conventional double J (Vortek) stents after uncomplicated flexible URS.
The main aim of the study is to investigate and compare the possible acute effect of standard PCNL, mini-PCNL and RIRS on renal function. Secondary aims are to investigate the efficacy (stone-free rate), safety (complication rate, long-term kidney function) and other parameters (operation, fluoroscopy and hospitalization time) concerning the 3 endourological operations (PCNL, mini- PCNL, RIRS) for the treatment of renal calculi.
Shock wave lithotripsy (SWL) is recommended for kidney stones < 20 mm. However, the stone clearance of lower pole calculi after SWL is limited, thus leading to an extended indication for mini-percutaneous nephrolithotripsy (PCNL) even for stones between 10 and 20 mm in many centers. This trend is further promoted by introduction of super-mini PCNL (SMP), which is postulated to be less invasive compared to mini-PCNL due to the miniaturized instruments. However, this issue remains controversial. On the other hand, improvements in endoscopy technology have made retrograde stone removal more attractive. This has led to an increasing use of RIRS as a primary treatment although it is recommended only as 2nd-line option by current guidelines. However, the treatment of symptomatic lower pole calculi is a challenge for RIRS because of lower clearance rates. The purpose of this study is to evaluate the efficacy and safety of SMP and RIRS for the treatment for symptomatic lower pole calculi renal calculi measuring 10-20 mm.
Outpatient tubeless Percutaneous nephrolithotomy (PCNL) could potentially improve patient care and result in significant cost savings for our hospital each year. If this pilot study is successful, Queen's/KGH will lead a collaborative national multicentre trial to further establish the role of this new approach in the surgical treatment of kidney stones.
The purpose of this clinical study is to evaluate BackStop, a polymer-based device that is intended to be used during ureteroscopic lithotripsy to prevent retrograde stone migration. It is a water soluble polymer with reverse thermosensitive properties; the polymer exists as a liquid at low temperature (below 17 C) and rapidly transitions to a high viscosity gel at body temperature (i.e. in the ureter). BackStop is injected above the stones in the ureter and is intended to prevent retrograde migration of stones during ureteroscopic lithotripsy. Upon completion of the lithotripsy procedure, BackStop dissolves naturally or by irrigation. The study hypothesis is that a greater proportion of patients will experience no retropulsion of a kidney stone when BackStop is used versus no anti-retropulsion device when undergoing intracorporeal lithotripsy.
The objectives of the study are to assess the systemic exposure, safety and efficacy of three concentrations of OMS201 in subjects undergoing retrograde ureteroscopic removal of upper urinary tract stones.
The purpose of this study is to determine the clinical effects of a triclosan stent on adherent bacteria, stent biofilms, and patient urine cultures in patients with an indwelling triclosan ureteral stent. The patient populations that will be tested include: patients following ureteroscopy and patients scheduled to undergo shockwave lithotripsy who require a ureteral stent. It is hypothesized that triclosan eluting ureteral stents will reduce the number of bacteria both on (within biofilm) and around (in the urine) a ureteral stent.
Urolithiasis is a common condition in the United States, and is associated with significant morbidity and even mortality. The most commonly occurring urinary calculi are comprised of calcium oxalate salts, and until recently, the pathogenesis of calcium oxalate calculi was poorly understood. New evidence, however, suggests that the development of calcium oxalate calculi may be intimately associated with hydroxyapatite (HA) plaque, also known as Randall's plaque, which is located on the renal papillae. The investigators have previously demonstrated that Randall's plaque originates in the thin ascending limb of the loop of Henle, and they have shown that Randall's plaque is composed of HA (Evan, Lingeman et al. 2003). As well, the amount of Randall's plaque correlates with elevated levels of urinary calcium and decreased urinary volume, risk factors for the formation of calcium oxalate calculi (Kuo, Lingeman et al. 2003). In the course of these previous studies, the investigators have anecdotally noted that calcium oxalate stones are often found attached to Randall's plaque, an observation that others have reported as well (Prien 1949; Carr 1954; Cifuentes Delatte, Minon-Cifuentes et al. 1987). However, there has been no in-vivo, rigorous documentation of this "attached stone" relationship. Attached calculi represent an important point in the pathogenesis of calcium oxalate calculi, as they correspond to a moment in time where there is a continuum between the HA plaque of Randall and the calcium oxalate stone, thus linking the origin of plaque with the development of stone. A better understanding of the phenomenon of attached calculi will lead to a better understanding of how and why calcium oxalate stones form, which may ultimately direct future interventions to attenuate stone activity.
Patients with large or otherwise complex renal calculi are commonly treated by percutaneous nephrolithotomy (PNL; PERC). PERC requires the creation of an approximately 10 mm channel through the renal parenchyma, into the intra-renal collecting system, in order to effect stone fragmentation and extraction. Although the nephrostomy tract is confined to a small fraction of the renal parenchyma (approximately 1%), the trauma associated with the creation of the tract will affect blood flow and oxygen delivery to regions beyond the immediate site of injury. It is possible that this could result in a significant functional renal impairment. There are several reports describing the effect of PERC on renal function, but interpretation of these studies is difficult, due to a lack of uniformity in patient selection and variability in the timing of peri-operative evaluation. Recent data from the investigators' lab, obtained from a porcine model, suggest that, acutely, PERC causes a significant decrease in renal function as measured by para amino hippurate (PAH) clearance. The purpose of this study is to determine, in a rigorous and standardized fashion, the acute effects of PERC on renal function, as measured by nuclear renography.