View clinical trials related to Nephrolithiasis.
Filter by:The Study of whether or not Ureteral Stent Length affects patient comfort after electro-shock wave treatment for kidney stones.
Telerounding is the use of wireless remote video-confrencing to assess hospitalized patients. Physicians thus rely on all ususal data collected during bedside rounds with the exeption of a direct physical exam. The intention of this study is to determine if post-operative morbidity can be identified in an accurate and timely manner.
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.
The response to opioids varies greatly among individuals. Some of these variability is accounted for by genetic factors. The present study was designed to evaluate the possibility that genetic polymorphism in the gene encoding for mu opioid receptor may explain variability in the response to alfentanil during lithotripsy.
Kidney stones are very common. They affect 3-5% of the population in the United States. Many people are hospitalized for the treatment of kidney stones and some may die. Better understanding of what causes kidney stones is useful in both the treatment and prevention of kidney stones. However, exactly what causes kidney stones is unknown. The most common type of kidney stones contains calcium, which sometimes is attached to a part of the kidney important in producing the final urine, called the papilla. The investigators have noticed that persons who form kidney stones seem to have more papilla with stones attached. They propose to study these areas of the papilla, called Randall's plaques (named after their discoverer), in patients undergoing surgery for kidney stones.
Test the hypothesis that the new bariatric surgical procedures (BSP) increase stone risk, and will result in an increased incidence and prevalence of stone disease; the purpose is to determine if BSP patients require special management for stone prevention. This study does not include the bariatric surgery but enrolls subjects who are already scheduled for surgery with an affiliated surgeon. The study procedure is to collect 24 hour urines pre-and post surgically to evaluate the risk of kidney stone procedure after surgery.
Current practices of the diagnosis of urinary stones gives little information on the probable fragility of stones using shock wave lithotripsy (SWL), and many patients receive more SW's than is necessary to break up their stones. Indeed, some patients are treated with SWL when their stones cannot be fragmented using this technology. The investigators have ample evidence that computed tomography (CT) images of kidney stones can reveal significant internal structure in stones—structure that is likely to be useful in predicting stone fragility—but no one has explored the use of clinical helical CT for this purpose. Also, the investigators do not know the effect that the human body wall and kidney tissue will have on the resolution of kidney stone structure with helical CT.
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.
Historically, percutaneous treatment of stone-bearing caliceal diverticula has resulted in the best success rates when examining factors such as symptom relief and stone-free rates (Jones, et al, 1991). Many groups have reported modifications in their percutaneous approach which have reportedly improved patient outcomes, but these series have very limited populations. Another issue concerning stone-bearing caliceal diverticula centers on the etiology of stones formation within these areas. This topic remains a subject of debate, with conflicting data in the literature.