Detailed Metabolic Evaluation Research Articles

Is stone free status really necessary for metabolic evaluation following stone removal procedures?

ObjectiveTo evaluate the impact of stone free status on the outcomes of metabolic evaluation in recurrent stone formers after ureteroscopic stone removal. Patients and methodsA total of 78 patients undergoing retrograde intrarenal surgery (RIRS) for renal stones were included and cases were divided into two groups after 4 weeks based on the NCCT findings. While cases in the Group 1 (n = 54) was completely stone free, cases in Group 2 (n = 24) had residual fragments in the kidney. A full 24-h urine analysis for relevant stone forming risk factors has been performed after 4 weeks following the fURS procedures in all patients of both groups. Outcomes of metabolic evaluation (24-h urine and serum) have been comparatively evaluated in both groups. ResultsEvaluation of the preoperative serum and urine stone forming risk factors revelaed no statistical difference in both groups. Comparative evaluation of the 24-h urinary stone forming risk factors also revealed no statistically significant difference between preoperative and postoperative findings in cases of Group 2 with residual stones. Last but not least, no significant difference was observed between the mean preoperative and postoperative serum variables between two groups. ConclusionsOur results show that in the light of the similar metabolic evaluation outcomes obtained in cases with and without residual fragments, ‘stone free status’ may not be an essential factor to perform a detailed metabolic evaluation (24-h urine analysis and serum parameters) after endourological stone removal procedures.

Valoración del impacto de la tasa libre de litiasis en los resultados de la evaluación metabólica

ObjectiveTo evaluate the impact of stone free status on the outcomes of metabolic evaluation in recurrent stone formers after ureteroscopic stone removal. Patients and methodsA total of 78 patients undergoing retrograde intrarenal surgery (RIRS) for renal stones were included and cases were divided into two groups after 4 weeks based on the NCCT findings. While cases in the Group 1 (n=54) was completely stone free, cases in Group 2 (n=24) had residual fragments in the kidney. A full 24-hour urine analysis for relevant stone forming risk factors has been performed after 4 weeks following the fURS procedures in all patients of both groups. Outcomes of metabolic evaluation (24-hour urine and serum) have been comparatively evaluated in both groups. ResultsEvaluation of the preoperative serum and urine stone forming risk factors revelaed no statistical difference in both groups. Comparative evaluation of the 24-hour urinary stone forming risk factors also revealed no statistically significant difference between preoperative and postoperative findings in cases of Group 2 with residual stones. Last but not least, no significant difference was observed between the mean preoperative and postoperative serum variables between two groups. ConclusionsOur results show that in the light of the similar metabolic evaluation outcomes obtained in cases with and without residual fragments, ‘stone free status’ may not be an essential factor to perform a detailed metabolic evaluation (24-hour urine analysis and serum parameters) after endourological stone removal procedures.

Detailed metabolic evaluation in primary stone formers: Is it recommended? Comparing detailed metabolic evaluation outcome between primary and recurrent stone formers

Detailed metabolic evaluation in primary stone formers: Is it recommended? Comparing detailed metabolic evaluation outcome between primary and recurrent stone formers

Pediatric renal stone disease

Pediatric renal stone disease is manifested as nephro/urolithiasis (UL) and/or nephrocalcinosis (NC). Compared to adults, UL in childhood is less common, and it is believed to be around 5% in industrialized countries, while the incidence of NC is even lower except for critically ill premature infants in whom it may reach 64%. The formation of UL and NC is caused by increased concentration of relevant solutes, and their aggregations and adherence to the renal tubules cell is facilitated by factors such as urine pH, inability of natural crystallization inhibitors, stasis of urine as well as renal tubule damage. UL is associated with significant morbidity because of pains, susceptibility to urinary tract obstruction and infections, and the necessity of surgical procedures. NC is usually asymptomatic but is frequently progressive, and more often than UL, leads to chronic renal failure. Although other imaging modalities can be used in the diagnosis of renal stone disease, ultrasound has the least risk and is most cost-effective. The majority cases of UL and NC in children are of metabolic origin and thus they are prone to recurrence and may cause chronic renal damage. Therefore, they deserve, even after their initial presentation a detailed metabolic evaluation. Genetic source of renal stone disease is suspected in the following conditions: early onset, familial prevalence, familial consanguinity, multiple or recurrent stones, and NC. For all UL/NC etiologies early identification and personalized treatment of the basic disorder is the most important.

Epidemiology of pediatric urolithiasis

Pediatric urolithiasis is an endemic disease in certain parts of the world, namely Turkey and the Far East. As a recurrent pathology which may reveal functional as well and morphologic changes in the urinary tract, environmental factors together with urogenital abnormalities should be evaluated thoroughly in each patient. The aims of management should be complete clearance of stones, treatment of urinary tract infections, and preservation of renal function and prevention of stone recurrence. In addition to certain minimally invasive stone removal procedures, treatment of pediatric urolithiasis requires a detailed metabolic evaluation in all patients on an individual basis. Obstructive pathologies have to be corrected immediately and children with a positive family history should be followed carefully with respect to a high likelihood of stone re-growth and recurrence. Although specific management of each metabolic abnormality seems to be the key factor in the medical management of stone disease, as general advice each child should be forced to adequate fluid intake which will reveal the urine volume increase in accordance with the body mass index. Moreover, medical therapeutic agents that increase urine citrate levels should be encouraged.

Metabolic disorders: stones as first clinical manifestation of significant diseases.

Metabolic syndrome, type 2 diabetes, and primary hyperparathyroidism are metabolic disorders that should deserve a special focus in renal stone patients as a pathogenic link is established with some stone components. Indeed, an acidic urinary pH due to a decreased ammonium bioavailability explains the high prevalence of uric acid stones in patients with metabolic syndrome or diabetes and, primary hyperparathyroidism induced hypercalciuria increases the risk of calcium phosphate stones. We report here four clinical cases of renal stone patientswith metabolic disorders encountered in a daily practice.Clinical andmetabolicfindings altogether with stone analysis componentspresented here,illustrate relevant pathophysiological links. 24 hours urine evaluation and stone analysis which includes both morphological typingand infrared spectroscopy, are key diagnostic steps for early recognition of metabolic disorders. Metabolic screening allows diet related stone identification, points out stone risk factors and identifies patients'comorbidity. The occurrence of nephrocalcinosis with or without chronic renal failure should require a more detailed metabolic evaluation in order to identify uncommon etiologies such as renal tubular acidosis.

Current medical treatment in pediatric urolithiasis.

Although the prevalence of urolithiasis is nearly 2-3% in childhood, the risk of recurrence may range from 6.5-54%. There has been an increase in urinary stone disease among pediatric age groups, and stone disease has a multifactorial etiology. After the diagnosis, detailed metabolic evaluation is required. High recurrence rates, therapeutic irregularities and deficiency in diagnosis may lead to comorbidities such as loss of kidney function. Following diagnosis, the requirement for surgery, such as stone extraction and correction of anatomical anomalies, is determined. Medical and supportive treatments are also needed to prevent recurrence and urinary tract infections and to preserve renal function. Supportive care includes increased fluid intake and dietary modifications. Medical treatment is dependent on the cause of the urinary stone disease. The morbidities associated with pediatric urolithiasis can be prevented by early diagnosis, detailed metabolic analysis, regular follow-up and medical treatment protocols.

Metabolic and demographic characteristics of children with urolithiasis in Western Turkey

Pediatric urolithiasis is an endemic disease in Turkey. We evaluated the clinical, radiological and metabolic features of children with urolithiasis in Western Turkey. We retrospectively reviewed the records of 85 children with urolithiasis who were followed-up between 2004 and 2010 in Pediatric Nephrology Department of Celal Bayar University, Manisa. The male/female ratio was 1.23/1. The mean age at diagnosis was 66.1 months (range 3-210 months). Family history of urolithiasis was found in 58 (68.2%) patients. 23 (27%) patients were born from consanguineous marriages. Stones were located in the upper urinary tract in 79 (92.9%) patients. In 66 (77.6%) patients, stones were single-sided and 41 (48.2%) patients had multiple stones. Calcium oxalate stones were the most common one among patients in whom stone analysis was performed (78.5%). Hypocitraturia was the most commonly detected urinary metabolic risk factor. In patients who were under 12 months of age at diagnosis, hypercalciuria was the most commonly seen urinary metabolic risk factor. At the end of follow-up period, 24 patients became free of stone disease and 4 patients had recurrence. In conclusion, metabolic abnormalities are common in pediatric stone patients and are strongly associated with recurrence. Considering that urolithiasis in children is an important risk factor for renal failure, early diagnosis, detailed metabolic evaluation and implementing appropriate treatment and follow-up protocols may prevent recurrence and renal damage.

Medical management of urinary stone disease

Kidney stones occur in ~ 10% of patients in their lifetimes, and > 10 crystal types have been reported in the literature. After treatment, a subset of these patients will have recurrent calculi, leading to significant morbidity and potential for serious chronic renal disease. Detailed metabolic evaluation is indicated in patients at high risk for stone recurrence, as a reversible metabolic abnormality can be identified in > 90% of them. Once the patient’s underlying physicochemical and physiologic derangements are defined, targeted medical therapy can be initiated in order to prevent growth of pre-existing stones and new stone formation. In this report, the author provides a comprehensive review of the presently available selective and nonselective pharmacologic treatments for stones. Several exciting investigational pharmaceutical agents for kidney stone prevention are also discussed. Although many of these agents are effective, there remain clinical scenarios in which existing medicines are insufficient.

Pediatric urolithiasis: etiology, specific pathogenesis and medical treatment

Pediatric urolithiasis is an endemic disease in certain parts of the world, namely Turkey and the Far East. As a recurrent pathology which may reveal functional as well and morphologic changes in the urinary tract, environmental factors together with urogenital abnormalities should be evaluated thoroughly in each patient. The aims of management should be complete clearance of stones, treatment of urinary tract infections, preservation of renal function and prevention of stone recurrence. In addition to certain minimally invasive stone removal procedures, treatment of pediatric urolithiasis requires a detailed metabolic evaluation in all patients on an individual basis. Obstructive pathologies have to be corrected immediately and children with a positive family history should be followed carefully with respect to a high likelihood of stone re-growth and recurrence. Although specific management of each metabolic abnormality seems to be the key factor in the medical management of stone disease, as general advice each child should be forced to adequate fluid intake which will reveal the urine volume increase in accordance with the body mass index. Moreover, medical therapeutic agents which increase urine citrate levels should be encouraged.

A Practical Approach to Nephrolithiasis

Detailed metabolic evaluation and prophylaxis for all patients presenting with a first renal stone seems inappropriate. The crucial clinical problem lies in predicting which patients are likely to have a recurrence. Stone composition is an important guide for the physician's decisions concerning investigation and a rational choice of treatment.

Hypercalciuria in children with urolithiasis.

The pathogenetic roles of idiopathic renal hypercalciuria and absorptive hypercalciuria in children with urolithiasis have not yet been determined. Oral calcium loading studies were performed in 21 children with unexplained calcareous urolithiasis. Thirteen children, aged 20 months to 17 years, were found to have renal hypercalciuria after an overnight fast (urinary calcium-urinary creatinine [UCa/UCr] ratio in milligrams, greater than 0.21). Four children were found to have absorptive hypercalciuria. In this group, fasting UCa/UCr values were normal (SEM, 0.12 +/- 0.02); however, UCa/UCr values were elevated (SEM, 0.31 +/- 0.01) after the oral calcium load. Serum parathyroid hormone values were normal in all children with hypercalciuria. Urinary calcium excretion was normal in four patients. These data indicate that hypercalciuria may frequently occur in children with urolithiasis and that detailed metabolic evaluation is warranted in children with kidney stone disease.

“Masked” 21-hydroxylase deficiency of the adrenal presenting with gynecomastia and bilateral testicular masses

An infertile 27 year old man with precocious puberty is described. He presented in adulthood with unilateral and then bilateral gynecomastia, and subsequently testicular tumors developed. An early diagnosis of congenital adrenal hyperplasia would have avoided unnecessary surgery. Initial detailed metabolic evaluation led to the erroneous diagnosis of 11-hydroxylase deficiency because of the presence of an unusual steroid (21-desoxycortisol) in serum which was falsely reported as an increased 11-desoxycortisol (compound S). The observed low urinary pregnanetriol measurements would have supported this diagnosis. Subsequent specific measurements of 21-desoxycortisol established its presence in the serum and its major metabolite, tetrahydro-21-desoxycortisol, in the urine. The unique features in this case of 21-hydroxylase deficiency alert the physician to its unusual clinical presentation and the pitfalls that may be encountered when evaluating adrenal steroidogenesis.