Preventive fluid and dietary therapy for urolithiasis: An appraisal of strength, controversies and lacunae of current literature

Kidney collecting system anatomy applied to endourology - a narrative review

OBJECTIVE

To evaluate the surgical anatomy of the kidney collecting system through a narrative review of the literature, highlighting its importance during diagnosis and its approach during surgical procedures for the treatment of renal stones.

MATERIAL AND METHODS

We carried out a review about the anatomy of the kidney collecting system. We analyzed papers published in the past 40 years in the databases Pubmed, Embase and Scielo, and we included only papers in English and excluded case reports, editorials and opinions of specialists.

RESULTS

Renal collecting system could be divided in four groups: A1 - kidney midzone (KM), drained by minor calyx that are dependent on the superior or the inferior caliceal groups; A2 - KM drained by crossed calyx, one draining into the superior caliceal group and another draining into the inferior caliceal group; B1 - KM drained by a major caliceal group independent of both the superior and inferior groups; and B2 - KM drained by minor calyx entering directly into the renal pelvis. Some details and anatomic variations of the collecting system are related to clinical and radiological aspects, particularly perpendicular calyces, interpyelocalyx space, position of calyces in relation to renal border, classification of the renal collecting system, infundibular diameter and the angle between the lower infundibulum and renal pelvis.

CONCLUSION

The knowledge of intra-renal collecting system divisions and variations as the angle between the renal pelvis and lower infundibula, position of the calices in relationship with renal edge and the diameter and position of the calyces are important for the planning of minimally invasive renal surgeries.

Anti-urolithiatic activity of Bryophyllum pinnatum Lam. hydroalcoholic extract in sodium oxalate-induced urolithiasis in rats

Background and Aim

Despite advances in modern medicine, the development and growth of calculi continues to be a source of concern for mankind, as there is no effective treatment for kidney stones. In the present study we investigated antiurolithiatic activity of Bryophyllum pinnatum Lam against sodium oxalate (NaOx) induced urolithiasis in rats.

Experimental procedure

In rats with renal calculi caused by sodium oxalate (NaOx, 70 mg/kg, i.p.); the antiurolithiatic action of Bryophyllum pinnatum hydroalcoholic extract (BPHE) was studied. BPHE was given every day orally at doses of 50, 200 mg/kg for 14 days to rats to examine activity against sodium oxalate (NaOx) mediated urolithiasis, with Cystone (500 mg/kg, p.o.) as a reference standard. The effect of the extract on urine oxalate, creatinine and phosphate retention and excretion in the kidney, as well as serum and biochemical analysis of kidney homogenate and histopathological examinations were studied.

Results and conclusion

Oral administration of BPHE at doses of 50,100, and 200 mg/kg to rats with sodium oxalate-mediated renal calculi showed dose-dependent substantial (P<0.05) antiurolithiatic potential, with notable reversal of NaOx-induced ion excretion and urinary CaOx concentration. These findings justify the traditional use of Bryophyllum pinnatum hydroalcoholic extract (BPHE) in the treatment of renal calculi.

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Supporting its traditional use in renal calculi.

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Demonstrated dose-dependent antiurolithiatic capacity.

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A notable reversal of NaOx-induced ion excretion.

Nutritional status assessed by the Controlling Nutritional Status (CONUT) score as a predictor of recurrence of urolithiasis

PURPOSE

We aimed to determine the influence of nutritional status on urinary metabolic abnormalities and stone recurrence in patients with urolithiasis.

MATERIALS AND METHODS

We analyzed data for 464 stone-formers and 464 propensity-score-matched control patients that had been collected between 2003 and 2015. Nutritional status was evaluated by use of the Controlling Nutritional Status (CONUT) score, and patients were placed into two CONUT score categories (0-1 and ≥2). Serum and 24-hour urinary metabolites were evaluated in 464 stone-formers. Kaplan-Meier and multivariate Cox regression analyses were performed to assess the influence of nutritional status on stone recurrence. Stone recurrence was defined as radiographic appearance of new stones during the follow-up period.

RESULTS

Stone-formers showed a higher prevalence of poor nutrition (CONUT score ≥2) than did the propensity-score-matched control patients (p<0.001). Stone-formers who had poor nutritional status had significantly lower 24-hour urinary calcium but higher oxalate excretion (each p<0.05). Kaplan-Meier estimates demonstrated that stone-formers with poor nutritional status also experienced stone recurrence more rapidly (log-rank test, p=0.014). Multivariate Cox regression revealed that poor nutritional status was independently associated with stone recurrence (hazard ratio, 1.736; 95% confidence interval, 1.041-2.896; p=0.034).

CONCLUSIONS

The CONUT score, an easily measured immunonutritional biomarker, is independently associated with a higher risk for stone recurrence in patients with urolithiasis. This implies that not only dietary excess, but also undernourished status, may be associated with aberrations in urine physicochemistry and stone recurrence.

Effects of high-sodium diet on lithogenesis in a rat experimental model of calcium oxalate stones

Background

This study aimed to investigate the effects of a high- and low-sodium diets on lithogenesis in a rat experimental model of calcium oxalate stones.

Methods

Twenty male Wistar rats were randomly divided into four groups; group A: 4% NaCl+1% ethylene glycol (EG); group B: 8% NaCl+1% EG; group C: 8% NaCl+normal drinking-water; group D: 1% EG +normal diet. All rats were sacrificed 4 weeks later, and blood samples were collected from the heart. The kidneys were collected for Von Kossa staining to evaluate the formation of calcium-containing crystals. The last 24-h urine samples were also gathered for metabolic analysis.

Results

Von Kossa staining demonstrated that the rats in both group A and group B had significantly more renal calcium crystals than those in group D. However, 24-h urinary volume increased significantly (142.26±20.91 mL) in group B compared with group A (100.52±28.23 mL), group C (107.36±14.24 mL), group D (40.79±8.71 mL) (P=0.004, 0.012, and 0.000 respectively). Level of urine sodium (Na), potassium (K), chlorine (Cl), and calcium (Ca), urea nitrogen were significantly higher in group B compared with group D. The urine phosphorus, oxalate, and creatinine levels; urine specific gravity; and urine PH were similar between group B and group D. The level of serum sodium was higher in group B (151.26±4.06 mmol/L) compared with group D (145.56±1.12 mmol/L) (P=0.002).

Conclusions

A high sodium intake might increase the risk of lithogenesis in susceptible individuals (given by EG) or in individuals with water restriction.

The association between dietary intakes and stone formation in patients with urinary stones in Shiraz

Background: Kidney stone is a common and costly disease, but it may be improved by a healthy diet. The aim of this study was to evaluate the association between dietary intake and stone formation in patients with urinary stones in Shiraz.

Methods: In this cross sectional study, 110 patients with kidney stone were selected from Faghihi hospital, Shiraz. Demographic information was collected, and anthropometric indices, disease-related variables, physical activity (using IPAQ), and dietary intake (using food frequency questionnaire, analyzed by Nut 4 software, to estimate micro and macro nutrients) were evaluated. Independent sample t test and one-way ANOVA were used to compare the quantitative variables between the 2 groups and multi groups, respectively. Chi square test was also used to compare qualitative variables. The correlation between variables was determined using Pearson test.

Results: Out of 110 participants in this study, 37 (33.6%) were female, with the mean BMI of 27.0 ± 4.68 kg/m2, and 73 (66.4%) were male, with the mean BMI of 24.21±2.96 kg/m2. The mean intake of calcium-containing foods (p=0.02) and high-fructose beverages (p=0.03) was significantly greater in patients with calcium stones compared to those with uric acid stones. The mean intake of high-purine foods was significantly higher in patients with uric acid stones than in those with calcium stones (p=0.007). The mean intake of vitamin A (p=0.02), beta-carotene (p=0.03), and fructose (p=0.03) was significantly higher in patients with calcium stones than in those with uric acid stones, while caffeine intake was significantly higher in patients with uric acid than in those with calcium stones (p=0.01). There was a significant correlation between consumption of high-oxalic beverages (p=0.005, correlation coefficient = 0.26) and high-fructose (p=0.048, correlation coefficient = 0.18) with spontaneous stone expulsion.

Conclusion: There was a significant relationship between consuming vitamin A, beta-carotene, and foods containing calcium, purine, fructose, and oxalate and formation of kidney stones. Therefore, adopting a healthy diet and increasing physical activity may be effective in the treatment of kidney stones.

The Demographic Diversity of Food Intake and Prevalence of Kidney Stone Diseases in the Indian Continent

Food intake plays a pivotal role in human growth, constituting 45% of the global economy and wellbeing in general. The consumption of a balanced diet is essential for overall good health, and a lack of equilibrium can lead to malnutrition, prenatal death, obesity, osteoporosis and bone fractures, coronary heart diseases (CHD), idiopathic hypercalciuria, diabetes, and many other conditions. CHD, osteoporosis, malnutrition, and obesity are extensively discussed in the literature, although there are fragmented findings in the realm of kidney stone diseases (KSD) and their correlation with food intake. KSD associated with hematuria and renal failure poses an increasing threat to healthcare infrastructures and the global economy, and its emergence in the Indian population is being linked to multi-factorial urological disorder resulting from several factors. In this realm, epidemiological, biochemical, and macroeconomic situations have been the focus of research, even though food intake is also of paramount importance. Hence, in this article, we review the corollary associations with the consumption of diverse foods and the role that these play in KSD in an Indian context.

Role of Spiritual Sentiments in Improving the Compliance of Water Intake in Patients with Urolithiasis

The aim of this study was to compare the compliance for water intake and rate of recurrence between spiritually motivated and non-motivated patients of renal tract stone disease. It is a multi centric prospective cohort study, conducted in Department of Urology, Institute of Kidney Diseases and Peshawar Medical College, from January 10, 2009 to December 2012. A total of 180 patients with comparable demographic, IQ, EQ and BMI after achieving complete stone clearance were divided into two equal groups. Both groups were instructed to increase the water intake timetable according to AUA guidelines. Group 'A' comprising of 90 patients who were identified as spiritually motivated patients based on questioner of FICA 12 is also instructed that increasing the water intake is mentioned in contemporary Islamic medicine. No spiritual instruction was given to Group B. The instructed guidelines and practice for amount and timing of water intake were recalled from participants at the end of 6 and 12 months. The data were recorded on structured proforma and was analyzed using SPSS version 17. The mean age of the patient in Group A was 37.5 years (18-70 years), while in Group B it was 34 years (18-65 years). Urolithiasis affected predominantly male gender in both groups. Sixty-five patients (72.2 %) in Group A have significant compliance (p < 0.001) for water intake over Group B (46 %). The spiritually motivated Group A has significantly reduced rate of recurrence of stones in 23 patients versus 37 in Group B. The spiritually motivated patients had significantly better compliance for water intake and reduced rate of recurrence versus non-motivated individuals in urolithiasis.

Urolithiasis, Urinary Cancer, and Home Drinking Water Source in the United States Territory of Guam, 2006-2010

We reviewed patient records with a first-listed diagnosis of urolithiasis-also known as urinary tract or kidney stone disease, nephrolithiasis-upon discharge from Guam's sole civilian hospital during 2006 to 2010 and urinary cancer mortality records from the Guam Cancer Registry for 1970 to 2009 to determine the source of municipal water supplied to the patients' residence. The objective was to investigate a possible relationship between the sources of municipal water supplied to Guam villages and the incidence of urolithiasis and urinary cancer. We analyzed hospital discharge diagnoses of urolithiasis or renal calculi by calculating the incidence of first-mentioned discharge for urolithiasis or renal calculi and comparing rates across demographic or geographic categories while adjusting by age, sex, and ethnicity/race. We reviewed cancer registry records of urinary cancer deaths by patient residence. The annual incidence of hospitalization for urolithiasis was 5.22 per 10,000. Rates adjusted for sex or age exhibited almost no change. The rate of 9.83 per 10,000 among Chamorros was significantly higher (p < 0.05) than the rates among any other ethnic group or race. When villages were grouped by water source, rates of patients discharged with a first-listed diagnosis of urolithiasis, adjusted for ethnicity/race, were similar for villages using either well water (5.44 per 10,000) or mixed source water (5.39 per 10,000), and significantly greater than the rate for villages using exclusively reservoir water (1.35 per 10,000). No statistically significant differences were found between the water source or village of residence and urinary cancer mortality. Some Guam residents living in villages served completely or partly by deep well water high in calcium carbonate may be at increased risk for urolithiasis compared with residents living in villages served by surface waters. Although the risk appears to be highest in villagers of Chamorro ethnicity, residents should be aware of other contributing risk factors and steps to take to avoid developing this health problem.

Beneficial effect of Citrus limon peel aqueous methanol extract on experimentally induced urolithic rats

CONTEXT

Citrus limon (L.) Burm.f. (Rutaceace) is a commonly available fruit variety with high medicinal and industrial values.

OBJECTIVE

Lemon peel (LP) extract was studied as a potent preventive and curative agent for experimentally induced hyperoxaluric rats.

MATERIALS AND METHODS

Gas chromatography-mass spectrometry (GC-MS) analyses and toxicity study were performed for aqueous methanol LP extract. Twenty-four Wistar rats were segregated into four groups. Group 1: Control; Group 2: Urolithic (ethylene glycol (EG) - 0.75%); Group 3: Preventive study (EG + LP extract administration from 0th to 7th week); Group 4: Curative study (EG + LP extract administration from 4th to 7th week). Animals received LP extract daily by oral administration (100 mg/kg body weight) for 7 weeks.

RESULTS AND DISCUSSION

GC-MS analyses revealed that compound 6 was abundant in the LP extract (32%) followed by compound 1 (∼21%). The LD50 value of LP extract was found to be >5000 mg/kg of body weight. Urolithic rats showed significantly higher urinary calcium and oxalate (4.47 ± 0.44 and 18.86 ± 0.55 mg/24 h, respectively) excretion compared with control and experimental rats. Renal function parameters like urea (84 ± 8.5 and 96.1 ± 3.6 mg/dL), creatinine (1.92 ± 0.27 and 1.52 ± 0.22 mg/dL), and urinary protein (2.03 ± 0.02 and 2.13 ± 0.16 mg/24 h) were also reduced by LP extract (p < 0.001) and corroborated with tissue analyses (SOD, catalase, and MDA levels) and histological studies in normal and experimental animals. Immunohistochemical staining of THP and NF-κB in urolithic animals showed elevated expression than the control, while LP extract suppressed the expression of these proteins.

CONCLUSION

In conclusion, lemon peel is effective in curing kidney stone disease and also can be used to prevent the disease and its recurrence.

Bryophyllum pinnatum Leaf Extracts Prevent Formation of Renal Calculi in Lithiatic Rats

BACKGROUND

Bryophyllum pinnatum, commonly known as Pattharcaṭṭa, is used traditionally in ethnomedicinal practices for the treatment of kidney stone and urinary insufficiency.

AIM

The present study evaluated the effect of Bryophyllum pinnatum on ethylene glycol (EG)-induced renal calculi in rats.

MATERIALS AND METHODS

Renal calculi were induced in rats by administration of 0.75% EG in drinking water and co-treated orally with standard drug, Cystone (750 mg/kg), or alcoholic and hydro-alcoholic extracts in doses of 100, 200 and 400 mg/kg for 28 days. Weekly body weights were recorded. On day 29, urolithiasis was confirmed by assessing the urinary parameters (urine volume, pH, uric acid, calcium, phosphorus, oxalate, magnesium and creatinine clearance), serum biochemical parameters (creatinine, uric acid, urea, calcium, phosphorus and magnesium), oxidative stress parameters and histology of kidney.

RESULTS

Treatment with extracts attenuated the EG-induced decrease in body weight and elevation in urinary parameters (uric acid, calcium, phosphorus and oxalate) and serum biochemical parameters (creatinine, uric acid, urea, calcium, phosphorus and magnesium). Extract treatment also reversed EG-induced decrease in urine volume, pH, magnesium and creatinine clearance, oxidative and histological damages in kidneys. Results were comparable to standard drug, Cystone. Results indicated that EG administration caused renal calculi formation which is prevented by treatment with extracts. The observed antilithiatic effect may be attributed to the presence of high content of phenolics, flavonoids and saponins in the extracts.

CONCLUSION

Bryophyllum pinnatum leaves showed preventive effect against renal calculi formation and validates its ethnomedicinal use in urinary disorders. It further supports its therapeutic potential for the treatment of urinary calculi.

Nephropathy in dietary hyperoxaluria: A potentially preventable acute or chronic kidney disease

Hyperoxaluria can cause not only nephrolithiasis and nephrocalcinosis, but also renal parenchymal disease histologically characterized by deposition of calcium oxalate crystals throughout the renal parenchyma, profound tubular damage and interstitial inflammation and fibrosis. Hyperoxaluric nephropathy presents clinically as acute or chronic renal failure that may progress to end-stage renal disease (ESRD). This sequence of events, well recognized in the past in primary and enteric hyperoxalurias, has also been documented in a few cases of dietary hyperoxaluria. Estimates of oxalate intake in patients with chronic dietary hyperoxaluria who developed chronic kidney disease or ESRD were comparable to the reported average oxalate content of the diets of certain populations worldwide, thus raising the question whether dietary hyperoxaluria is a primary cause of ESRD in these regions. Studies addressing this question have the potential of improving population health and should be undertaken, alongside ongoing studies which are yielding fresh insights into the mechanisms of intestinal absorption and renal excretion of oxalate, and into the mechanisms of development of oxalate-induced renal parenchymal disease. Novel preventive and therapeutic strategies for treating all types of hyperoxaluria are expected to develop from these studies.