View clinical trials related to Kidney Calculi.
Filter by: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.
This study will assess improvement in the percentage of spontaneous stone passage for distal ureteral calculi for alfuzosin compared to placebo, decrease of pain and narcotic/analgesic use associated with stone passage, decrease of the time to spontaneous stone passage, shift in the size distribution of stones passed towards larger sizes.
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.
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.
Kidney stones vary in size from a tiny grain of sand to as large as filling the inside of the kidney. Treatment decisions depend on the size, location, and composition of the stone. Some kidney stones can be treated with lithotripsy (breaking up stones inside the body with shock waves created outside the body) or ureteroscopy (placing a small telescope up the urine channel to remove the stone). When stones are large in size or in the lower part of the kidney, a percutaneous (making a passage from the back into the kidney) procedure has been found to be the best method to remove the stones safely and efficiently. A passage is made into the back to allow a small telescope to see the stone and break it into fragments for removal. A small catheter is placed at the end of the procedure to allow the kidney to drain. The purpose of this study is to record information about your surgery into a database so we can look at how patients who have had this procedure have done over time. We hope that reporting the outcomes of this surgery will be helpful to urologists and patients in the future. There may be certain factors that can be identified through this study as having better outcomes that may help make future surgeries safer.
Gouty diathesis describes uric acid or calcium oxalate nephrolithiasis and low urinary pH (<5.5). A hereditary component has been outlined for several forms of nephrolithiasis (such as hypercalciuria, hyperoxaluria, cystinuria, renal tubular acidosis), leading to the hypothesis of a genetic predisposition to nephrolithiasis. At the Unit of Nephrology, Ospedali Riuniti di Bergamo, more than 100 patients affected by gouty diathesis are followed. Fifty percent of them has a familiarity for kidney stones formation. The aim of our study is to identify the genetic factors that predispose to the development of nephrolithiasis in patients with gouty diathesis.
High amounts of calcium in the urine (hypercalciuria) can cause development of kidney stones in children. Treatment for these children includes plenty of fluids, a low-salt diet and medications such as potassium citrate. A major advantage of potassium citrate, as compared to hydrochlorothiazide, is its lack of side effects. One problem the researchers and others have observed is that some children continue to form kidney stones despite correction of hypercalciuria with potassium citrate. One possible explanation is that in some individuals potassium citrate therapy results in an excessive elevation of urine pH, a situation that may predispose to calcium phosphate stone formation. In this study, the researchers will study the effects of potassium citrate on urine chemistries and acid-base balance in three groups of children aged 5-17 years: - children who are hypercalciuric stone formers; - healthy children without a history of hypercalciuria or kidney stones. Particular attention will be paid to try to identify those who develop a very high urine pH (>8) and the factors leading to this metabolic reaction. The researchers will try to learn whether it is the child's characteristics, the disease manifestations, the dose of the drug, or a combination of the above which may be the cause of the development of very alkaline urine. Based on the results, the researchers hope to be able to better "tailor" the individual treatment for each child with kidney stones.
OBJECTIVES: I. Evaluate the ability of a slow-releasing formulation of neutral potassium phosphate to correct hypercalciuria and prevent recurrent stone formation in patients with absorptive hypercalciuria. II. Evaluate the safety of this treatment. III. Compare the efficacy of potassium phosphate to that of potassium citrate.