Nephrolithiasis and/or nephrocalcinosis is significantly related to renal dysfunction in patients with primary Sjögren's syndrome

OBJECTIVE

The present study compared the clinical features of patients with primary Sjögren's syndrome (pSS) with and without nephrolithiasis and/or nephrocalcinosis to determine factors related to renal dysfunction.

METHODS

The clinical features of 68 patients with anti-Sjogren's syndrome antigen A (SSA)/Ro-antibody-positive pSS with and without nephrolithiasis and/or nephrocalcinosis who underwent abdominal computed tomography and/or ultrasonography were retrospectively analysed.

RESULTS

Of the 68 patients with anti-SSA-antibody-positive pSS, 23 (33%) had renal nephrolithiasis and/or nephrocalcinosis, whereas 45 (67%) did not. Fourteen (20%) patients had renal dysfunction at diagnostic imaging. Among five patients who underwent renal biopsy, four patients with renal nephrolithiasis and/or nephrocalcinosis were diagnosed with tubulointerstitial nephritis, and one without nephrolithiasis and/or nephrocalcinosis was diagnosed with minimal change nephrotic syndrome. Estimated glomerular filtration rate at diagnostic imaging was significantly lower in patients with than without nephrolithiasis and/or nephrocalcinosis group (P = 0.010). In addition to nephrolithiasis and/or nephrocalcinosis (odds ratio [OR], 3.467; P = 0.045), the gap between serum sodium and chloride concentrations (OR, 10.400; P = 0.012) and increased urinary β2-microglobulin (OR, 5.444; P = 0.033) were associated with renal dysfunction at the time of diagnostic imaging.

CONCLUSION

Nephrolithiasis and/or nephrocalcinosis, normal anion gap metabolic acidosis, and tubulointerstitial damage are associated with renal dysfunction in patients with pSS.

Use of Low-Dose Computed Tomography in Children With Nephrolithiasis: An Analysis From 2 Tertiary Pediatric Centers

INTRODUCTION

Although ultrasound (US) is the preferred first-line imaging for pediatric nephrolithiasis, CT may be necessary in cases of a nondiagnostic US or when US in not available. Utilization of dose reduction strategies in children undergoing CT for nephrolithiasis is not well described. We compared use of low-dose CT (LDCT) in children presenting to 2 pediatric centers.

METHODS

We performed a retrospective chart review of children ≤ 17 years of age presenting with suspected nephrolithiasis to 2 tertiary children's hospitals, inclusive of those referred to these centers from nonpediatric facilities between 2013 and 2019. Children were included with an index CT scan from either the pediatric or referring center while those who had prior documented CT for nephrolithiasis within the study period or missing radiation dose assessment were excluded. The primary outcome was LDCT as defined as radiation dose < 3 mGy. The primary comparator was pediatric vs outside referral center. Exploratory analysis evaluated other factors associated with LDCT, including radiation dosage as a continuous variable.

RESULTS

A total of 155 individuals met inclusion criteria, with 126 (81.3%) receiving standard dose and 29 (18.7%) receiving LDCT. Pediatric facilities were more likely to utilize LDCT as compared to referral centers (P < .05). Older age and higher BMI were also found to be associated with increased radiation dose exposure.

CONCLUSIONS

Pediatric facilities utilized LDCT more frequently, although age and BMI may also influence imaging choices. An understanding of the factors associated with dose reduction in CT will impact future efforts to explore optimum imaging stewardship in pediatric nephrolithiasis.

Children With Type 1 Spinal Muscular Atrophy Are at Increased Risk for Nephrolithiasis

BACKGROUND

Nephrolithiasis is not a well-documented condition in children with spinal muscular atrophy (SMA). It is possible that this condition was underestimated before the era of nusinersen because of a much shorter life expectancy. We present our observational data on nephrolithiasis and its possible risk factors in children with type 1 SMA.

METHODS

We retrospectively reviewed the charts of 20 children with genetically confirmed type 1 SMA. Thirteen patients (aged 9 to 55 months) who underwent urinary tract ultrasonography were included in the study. Medical records were retrospectively reviewed for demographic and clinical characteristics, ultrasound results, and metabolic abnormalities.

RESULTS

Seven children (54%) had nephrolithiasis; 5 had multiple stones and two had a single stone. Two patients had microlithiasis (<3 mm), three had a stone in the size of 3 to 5 mm, and one had a stone in the size of more than 8 mm. Two patients with nephrolithiasis had urinary tract abnormalities. Patients with nephrolithiasis were more likely to have a history of urinary tract infections (UTIs) (P = 0.048) and higher urine specific gravity (P = 0.014) than patients without nephrolithiasis. Five of seven children with nephrolithiasis had a urine metabolic evaluation; all had hypercalciuria, three had hyperuricosuria, but none had hyperoxaluria, hypocitraturia, or hypomagnesemia.

CONCLUSION

Children with SMA type 1 are at an increased risk for nephrolithiasis. Hypercalciuria and high urine specific gravity appear to be the most common risk factors for the occurrence of nephrolithiasis. In addition, UTI is more common in patients with type 1 SMA with nephrolithiasis.

Efficacy of a fast-track pathway for managing uncomplicated renal or ureteral colic in a hospital emergency department: the STONE randomized clinical trial of Sonography and Testing of a Nephrolithiasis Episode

OBJECTIVES

To evaluate a fast-track pathway utilizing point-of-care (POC) testing and sonography as soon as uncomplicated renal or ureteral colic is suspected and to compare the POC clinical pathway to a standard one.

MATERIAL AND METHODS

Unblinded randomized controlled clinical trial in a hospital emergency department (ED). We enrolled patients with suspected uncomplicated renal or ureteral colic and randomized them to a POC or standard pathway (1:1 ratio). Duration of ED stay, treatments, the proportion of diagnoses other than uncomplicated colic, and 30-day complications were analyzed.

RESULTS

One hundred forty patients were recruited between November 2018 and October 2019; data for 124 were analyzed. The mean (SD) total time in the ED was 112 (45) minutes in the POC arm and 244 (102) in the standard arm (P .001). Treatments, alternative diagnoses, and complication rates did not differ.

CONCLUSION

The use of a fast-track POC pathway to manage uncomplicated colic in the ED is effective and safe. It also reduces the amount of time spent in the ED.

[Ultrasonography for diagnosis and management of nephrolithiasis: state of the art and new perspectives]

The correct management of patients with kidney stones is a crucial issue for nephrologists. In recent years, the incidence and prevalence rates of nephrolithiasis have maintained a growing trend worldwide, showing a strong correlation with other systemic disease such as diabetes mellitus, hypertension, obesity, metabolic syndrome and chronic kidney disease. International guidelines indicate computed tomography as the first choice for all adult patients with suspected acute symptoms for obstructive nephrolithiasis. Intravenous pyelogram is more useful in the follow-up of patients with relapsing nephrolithiasis and known stone composition, while the high costs and the long image acquisition times limit the routine use of magnetic resonance. Recent innovative tools have improved the accuracy of kidney stone localization and measuring with B-Mode and color Doppler imaging, thereby reducing the gap between ultrasonography and computer tomography. The aim of this review is to report the latest evidence on risk factors and on the pathophysiology of nephrolithiasis, and to compare the utility of the available imaging techniques in the management of patients with kidney stones, focusing on the role of ultrasonography and the present and future strategies to improve its accuracy.

Hypercalciuria: its value as a predictive risk factor for nephrolithiasis in asymptomatic primary hyperparathyroidism?

CONTEXT

The latest guidelines of the 4th International Workshop on Asymptomatic Primary Hyperparathyroidism (aPHPT) reintroduced hypercalciuria (i.e. urinary calcium > 400 mg/day) as criterion for surgery. However, the value of hypercalciuria as a predictor of nephrolithiasis and the correct cut-off values still need to be confirmed.

OBJECTIVE

To evaluate the prevalence of silent kidney stones in a large series of patients with aPHPT and the sensibility, specificity and predictive value of different cut-off values of hypercalciuria in identifying patients with nephrolithiasis.

DESIGN

One hundred seventy-six consecutive patients with aPHPT were evaluated at our Institution by serum and urinary parameters and kidney ultrasound.

RESULTS

Silent nephrolithiasis was found in 38 (21.6%) patients. In the univariate and multivariate model, hypercalciuria was a predictor of nephrolithiasis using the criterion of 400 mg/24 h [(OR 2.30, (1.11-4.82) P = 0.025], 4 mg/kg/bw [OR 2.65, (1.14-6.25) P = 0.023], gender criterion [OR 2.79, (1.15-6.79) P = 0.023] and the cut-off value derived from the ROC analysis [(> 231 mg/24 h) OR 5.02 (1.68-14.97) P = 0.004]. Despite these several predictive criteria, however, hypercalciuria had a low positive predictive value (PPV), ranging from 27.4 to 32.7%.

CONCLUSIONS

Hypercalciuria is a predictor of nephrolithiasis, but its PPV is low.

Current status of radiological protection in endourological procedures in Spain

OBJECTIVE

To discover the extent of training in radiological protection (RP) of Spanish urologists who perform endourological procedures, and to analyse the use of on ionising radiation control and protection measures.

MATERIAL AND METHODS

A survey conducted through the Plataforma de Investigación de Estudios Multicéntricos (PIEM) (Multicentre Study Research Platform) on the 1,894 associates of the Spanish Association of Urology, between April and October 2015. The questionnaire comprised 21 questions on endourological activity undertaken, RP training, and the use of protective measures, and personal dosimetry. Seventeen percent responded, and 238 surveys were eventually validated for study.

RESULTS

Sixty-three percent of the respondents had received no type of RP training, 25% had first level accreditation, and only 12% second level. Fifty-seven percent, 27%, and 2% of the urologists used flap, wrist and crystalline dosimetry respectively. Use of radiation protection measures was insufficient. Fifty-three percent of the urologists at greatest risk of exposure had had no training in RP, 30% did not use flap dosimetry, and 40% used neither an apron or thyroid collar during the endourological procedures.

CONCLUSIONS

RP training, dosis monitoring, and the use of ionising radiation protective measures are insufficient, even by practitioners most exposed to radiation. It is essential that these serious shortcomings in RP are corrected, at the level of the individual, in urology departments, scientific societies, and the health authorities.

Innovations in Ultrasound Technology in the Management of Kidney Stones

This article reviews new advances in ultrasound technology for urinary stone disease. Recent research to facilitate the diagnosis of nephrolithiasis, including use of the twinkling signal and posterior acoustic shadow, have helped to improve the use of ultrasound examination for detecting and sizing renal stones. New therapeutic applications of ultrasound technology for stone disease have emerged, including ultrasonic propulsion to reposition stones and burst wave lithotripsy to fragment stones noninvasively. The safety, efficacy, and evolution of these technologies in phantom, animal, and human studies are reviewed herein. New developments in these rapidly growing areas of ultrasound research are also highlighted.

Radiation Mitigation Techniques in Kidney Stone Management

Patients with nephrolithiasis are exposed to significant quantities of ionizing radiation with the potential to cause secondary malignancy. This risk is magnified by the high recurrence rate of nephrolithiasis. In this article, we identify the risks of ionizing radiation as they pertain to patients with nephrolithiasis. We then identify evidence-based techniques for mitigating patient radiation exposure in the preoperative, intraoperative, and postoperative settings. Key factors include limiting the use of computed tomographic imaging, appropriate modulation of fluoroscopy settings, and minimizing rates of stone recurrence.

Efficacy analysis of self-help position therapy after holmium laser lithotripsy via flexible ureteroscopy

BACKGROUND

To observe the efficacy of self-help position therapy (SHPT) after holmium laser lithotripsy via flexible ureteroscopy (FURS).

METHODS

From January 2010 to November 2015, 736 nephrolithiasis patients who had received FURS lithotripsy were analyzed retrospectively. In position group, 220 cases accepted SHPT after lithotripsies, and 428 cases as control, coming from another independent inpatient area in the same center. The stone-free status (SFS) between two groups were compared at the 2nd, 4th and 12th week ends by X-ray examinations.

RESULTS

The preoperative incidence of hydronephrosis (25.9% vs. 18.0%, p = 0.018) or lower calyceal seeper (33.6% vs. 24.3%, p = 0.012) and the proportion of patients with > 2.0 cm stones (33.6% vs. 24.3%, p = 0.003) were all significantly higher in position group than in control group. There were no substantial difference between two groups in age, BMI, gender and medical histories. In postoperative followup, the incidence of hydronephrosis in position group was significantly lower than in control group (9.5% vs. 15.7%, p = 0.032) after removing double-J stents. In position group, the SFS of the 2nd week end (60.9% vs. 47.2%, p = 0.001), the 4th week end (74.1% vs. 62.8%, p = 0.004) and the 12th week end (86.9% vs. 79.4%, p = 0.021) were all significantly higher than those in control group.

CONCLUSIONS

SHPT after holmium laser lithotripsy via FURS may increase postoperative SFS, accelerate stone fragment clearance, and decrease the incidence of hydronephrosis after removal of double-J stents. The therapy does not require professional assistance and is economical, simple, and effective.

Stone culture in patients undergoing percutaneous nephrolithotomy: a practical point of view

INTRODUCTION

To determine the clinical yield of stone culture in patients undergoing percutaneous nephrolithotomy (PCNL), and to identify patients who may benefit from this test.

MATERIALS AND METHODS

We queried our database for all patients who underwent PCNL from 2005 to 2017, from whom urine culture (UC) and stone culture (SC) were obtained. Study endpoint was systemic inflammatory response syndrome (SIRS) within 48 hours of PCNL. Risk factors for SIRS and for stone colonization with highly resistant pathogens were evaluated. Based on UC and SC results, we determined the proportion of patients in whom SC may alter the treatment, had SIRS occurred, with respect to the initial empiric treatment.

RESULTS

The study group comprised of 512 patients with a median age of 53, of whom 323 (63%) were male. Positive UC were found in 137 (26.7%) patients, and positive SC in 117 (22.8%) patients. UC did not identify pathogens isolated from SC in 66 (12.8%) patients. Postoperative SIRS occurred in 50 (9.8%) patients. On multivariate analysis only SC was associated with postoperative SIRS. SC pathogens resistance rates ranged from 67% for treatment with 2nd generation cephalosporins to 9% for treatment with meropenem, and may alter the choice of antibiotics in 73 to 12 patients (14.2%-2.3% of the whole cohort), respectively.

CONCLUSIONS

In similar and earlier studies, we found substantial discordance between SC and UC results, and an association between stone colonization and SIRS. However, the practical yield of this test varies with the type of antibiotic given, and is limited when broad spectrum antibiotic is used.

[Application of 3D printing in urology]

The purpose of this article is to outline the role and possible applications of 3D printing in urology. At present, this technique provides the opportunity to choose the individual strategy of patient management, to conduct preoperative planning and surgical rehearsal; for medical specialists to reduce the learning curve in mastering modern complex surgical techniques, and for doctors and students to improve understanding of pathological processes in the kidney and the prostate gland.

Pediatric Nephrolithiasis: A Review

The incidence of pediatric nephrolithiasis is on the rise. The composition of kidney stones in children is different than in adults, as most stones in children have a composition of calcium oxalate and calcium phosphate mixed with a small amount of uric acid. The symptoms of pediatric nephrolithiasis are nonspecific. Computed tomography (CT) is the gold standard for diagnosis; however, because of radiation exposure associated with a CT scan, ultrasonography is also an accepted modality for the diagnosis. Extensive metabolic evaluation is important to rule out an underlying metabolic disorder. Urinary decompression, medical expulsion therapy, and surgical interventions such as ureteroscopy and extracorporeal shockwave lithotripsy are some of the options available for treating pediatric nephrolithiasis. [Pediatr Ann. 2017;46(6):e242-e244.].

[STANDARD TRANSCUTANEOUS AND ULTRA-MINI TRANSCUTANEOUS NEPHROLITHOTRIPSY IN TREATMENT OF NEPHROLITHIASIS]

Comparative analysis of two variants of transcutaneous nephrolithotripsy (TCNLT) in 45 patients, suffering nephrolithiasis, was performed. In 17 patients (the first group) the ultra-mini (UM) TCNLT, using tubus 11Сh, was done, and in 28 patients (the second group) – TCNLT, using a standard tubus 24Сh. The operation duration in the first group have had constituted (86.2 ± 16.3) min at average, and in the second group – (51 ± 13.6) min. The method of UМ TCNLT is a secure, miniinvasive, owing low rate of morbidity, comparing with a standard procedure, but with equal efficacy, concerning the «stone free» status (accordingly, 95.3 and 96.5%) in patients when calculi’s diameter up to 2 sm. Тubus 11Ch guarantees lesser risk of hemorrhagic complications occurrence, permits to conduct UM TCNLT without nephrostomic draining of the renal calyx and pelvis system more confidently.

[Techniques for percutaneous access during percutaneous nephrolithotomy.]

The creation of the access is one of the main steps in percutaneous nephrolithotomy, the most complicated for many urologists and the one that limited most the universalization of the technique. From a purely technical point of view, it includes puncture of the excretory tract and dilatation of the percutaneous tract to end with the introduction of an Amplatz type working sheath. The objective of the puncture is to try to access the excretory system through the renal papilla, minimizing the risk of bleeding. The puncture may be guided by ultrasound, fluoroscopy, both, under endoscopic or laparoscopic control, by CT scan or MRI, or even by application of new technologies (Robotic, augmented reality, electromagnetic navigation,...). Due to the versatility and independence involved in having the ability to perform the renal puncture in the operative room, as well as its influence in the results of PCNL, it must be the urologist himself who performs this basic step of percutaneous surgery. The tract may be dilated by Alken type metallic dilators, semirrigid Amplatz type dilators or high pressure balloons. To date, there is no single ideal dilatation method, being the selection based on the endourologist's experience and the knowledge of the advantages and limitations of each option. The objective of this review is to present the main methods for puncture guiding and tract dilatation for PCNL, as well as to provide technical details to improve its result.

[Modern diagnostic and management aspects of citrate therapy for uric acid nephrolithiasis]

INTRODUCTION

Iso-aciduria - long-term existence of urine pH within a narrow range (pH <0.8-1.2 units.) - activates certain enzymes for which these pH levels are favorable. Then, this activation induces precipitation of crystals corresponding to these enzymes.

OBJECTIVE

To enable citrate therapy without a risk of altering the stone chemical composition and to identify indicators reflecting the degree of metabolic disorders in patients with uric acid nephrolithiasis.

MATERIAL AND METHODS

Citrate therapy was provided with a mixture comprising "Potassium citrate monohydrate" and "Tri-sodium citrate di-hydrate" in a ratio of 2: 1. The study group included 64 patients, who had ultrasound-detected calyx stones and hyperechoic inclusions from 2 to 4 mm without acoustic shadow, located in the papillary region of the renal pyramids. Statistical analysis was performed by cross tabulations (pairing).

RESULTS

The results of the statistical analysis have proven the legitimacy and feasibility of the proposed method of classifying patients into homogeneous groups according to the disease severity.

CONCLUSION

Long-term citrate therapy should be carried out in such a way as to achieve maximum range of urine pH (from 5.4 to 7.8 units), which will allow to avoid deposition of other crystals upon the existing stone and identify indicators reflecting the degree of metabolic disorders in patients with uric acid nephrolithiasis.

CONCLUSION

Long-term citrate therapy should be carried out in such a way as to achieve maximum range of urine pH (from 5.4 to 7.8 units), thus avoiding deposition of other crystals upon the existing stone.

Cholelithiasis and Nephrolithiasis in HIV-Positive Patients in the Era of Combination Antiretroviral Therapy

Objectives

This study aimed to describe the epidemiology and risk factors of cholelithiasis and nephrolithiasis among HIV-positive patients in the era of combination antiretroviral therapy.

Methods

We retrospectively reviewed the medical records of HIV-positive patients who underwent routine abdominal sonography for chronic viral hepatitis, fatty liver, or elevated aminotransferases between January 2004 and January 2015. Therapeutic drug monitoring of plasma concentrations of atazanavir was performed and genetic polymorphisms, including UDP-glucuronosyltransferase (UGT) 1A1*28 and multidrug resistance gene 1 (MDR1) G2677T/A, were determined in a subgroup of patients who received ritonavir-boosted or unboosted atazanavir-containing combination antiretroviral therapy. Information on demographics, clinical characteristics, and laboratory testing were collected and analyzed.

Results

During the 11-year study period, 910 patients who underwent routine abdominal sonography were included for analysis. The patients were mostly male (96.9%) with a mean age of 42.2 years and mean body-mass index of 22.9 kg/m² and 85.8% being on antiretroviral therapy. The anchor antiretroviral agents included non-nucleoside reverse-transcriptase inhibitors (49.3%), unboosted atazanavir (34.4%), ritonavir-boosted lopinavir (20.4%), and ritonavir-boosted atazanavir (5.5%). The overall prevalence of cholelithiasis and nephrolithiasis was 12.5% and 8.2%, respectively. Among 680 antiretroviral-experienced patients with both baseline and follow-up sonography, the crude incidence of cholelithiasis and nephrolithiasis was 4.3% and 3.7%, respectively. In multivariate analysis, the independent factors associated with incident cholelithiasis were exposure to ritonavir-boosted atazanavir for >2 years (adjusted odds ratio [AOR], 6.29; 95% confidence interval [CI], 1.12–35.16) and older age (AOR, 1.04; 95% CI, 1.00–1.09). The positive association between duration of exposure to ritonavir-boosted atazanavir and incident cholelithiasis was also found (AOR, per 1-year exposure, 1.49; 95% CI, 1.05–2.10). The associated factors with incident nephrolithiasis were hyperlipidemia (AOR, 3.97; 95% CI, 1.32–11.93), hepatitis B or C coinfection (AOR, 3.41; 95% CI, 1.09–10.62), and exposure to abacavir (AOR, 12.01; 95% CI, 1.54–93.54). Of 180 patients who underwent therapeutic drug monitoring of plasma atazanavir concentrations and pharmacogenetic investigations, we found that the atazanavir concentrations and UGT 1A1*28 and MDR1 G2677T/A polymorphisms were not statistically significantly associated with incident cholelithiasis and nephrolithiasis.

Conclusions

In HIV-positive patients in the era of combination antiretroviral therapy, a high prevalence of cholelithiasis and nephrolithiasis was observed, and exposure to ritonavir-boosted atazanavir for >2 years was associated with incident cholelithiasis.

[Recurrent episodes of brushite nephrolithiasis revealing primary hyperparathyroidism]

INTRODUCTION

Nephrolithiasis is a frequent disease observed in 1 to 20 % of the general population. This disease predominates in male patients (2:1) and is characterized by a high rate of recurrences (about 50 %).

CASE REPORT

We report the case of a 45-year old male patient who experienced during about ten years recurrent bilateral renal colic episodes due to brushite lithiasis. These stones were treated with multiple extracorporeal shock wave lithotripsy sessions. A pyeloureteral junction syndrome predisposing to bulky stones formation has been put in evidence and required a pyeloplasty. After more than ten years of disease activity, a biochemical screening diagnosed primary hyperparathyroidism (PHPT). Radiological assessment identified a parathyroid gland adenoma. Successful surgical removal of this lesion was followed by resolution of the symptomatic kidney stones formation.

DISCUSSION

PHPT is associated with kidney stones in about 20 % of the patients. Hypercalciuria is the main risk factor of stones formation but other predisposing factors are also probably involved. Patients carrying a polymorphism located in the coding sequence of the calcium-sensing receptor gene or in the regulatory region of this gene seem to experience an increased occurrence of urinary lithiasis.

CONCLUSION

The present case stresses the importance of a metabolic assessment in all patients with recurrent nephrolithiasis, especially in case of bilateral episodes.

Ultrasonography versus computed tomography for suspected nephrolithiasis

BACKGROUND

There is a lack of consensus about whether the initial imaging method for patients with suspected nephrolithiasis should be computed tomography (CT) or ultrasonography.

METHODS

In this multicenter, pragmatic, comparative effectiveness trial, we randomly assigned patients 18 to 76 years of age who presented to the emergency department with suspected nephrolithiasis to undergo initial diagnostic ultrasonography performed by an emergency physician (point-of-care ultrasonography), ultrasonography performed by a radiologist (radiology ultrasonography), or abdominal CT. Subsequent management, including additional imaging, was at the discretion of the physician. We compared the three groups with respect to the 30-day incidence of high-risk diagnoses with complications that could be related to missed or delayed diagnosis and the 6-month cumulative radiation exposure. Secondary outcomes were serious adverse events, related serious adverse events (deemed attributable to study participation), pain (assessed on an 11-point visual-analogue scale, with higher scores indicating more severe pain), return emergency department visits, hospitalizations, and diagnostic accuracy.

RESULTS

A total of 2759 patients underwent randomization: 908 to point-of-care ultrasonography, 893 to radiology ultrasonography, and 958 to CT. The incidence of high-risk diagnoses with complications in the first 30 days was low (0.4%) and did not vary according to imaging method. The mean 6-month cumulative radiation exposure was significantly lower in the ultrasonography groups than in the CT group (P<0.001). Serious adverse events occurred in 12.4% of the patients assigned to point-of-care ultrasonography, 10.8% of those assigned to radiology ultrasonography, and 11.2% of those assigned to CT (P=0.50). Related adverse events were infrequent (incidence, 0.4%) and similar across groups. By 7 days, the average pain score was 2.0 in each group (P=0.84). Return emergency department visits, hospitalizations, and diagnostic accuracy did not differ significantly among the groups.

CONCLUSIONS

Initial ultrasonography was associated with lower cumulative radiation exposure than initial CT, without significant differences in high-risk diagnoses with complications, serious adverse events, pain scores, return emergency department visits, or hospitalizations. (Funded by the Agency for Healthcare Research and Quality.).

Renal papillary attenuation differences between primary and recurrent idiopathic calcium stone disease patients

AIM

The aim of this paper was to investigate whether renal papillae of patients with nephrolithiasis are more radiodense than that of control patients and to evaluate the predictability of urolithiasis using papillary density differences between stone and non-stone formers.

METHODS

Renal papillary Hounsfield Unit (HU) measurements were conducted at the level of upper pole, middle region and lower pole of both kidneys in a total of 126 primary (group 1), 133 recurrent (group 2) stone disease patients and 108 controls (group 3).

RESULT

Mean patient age did not differ significantly between groups (P>0.05). Mean stone diameters (±SD) were 5.0±3.1 mm (3-9 mm) and 6.1±3.3 mm (3-15 mm) for primary and recurrent groups, respectively and group distributions and variances were similar (P>0.05). Mean papillary attenuation values (±SD) were 27.26±9.30 (4.00-56.00) in group 1, 30.42±9.88 (12.00-64.00) in group 2 and 25.83±2.72 (20.30-32.56) in the control group. The difference between the mean papillary attenuation value of the primary stone disease group and the control group was statistically insignificant (P=0.104). When the control group and the recurrent stone group was compared without variances, in terms of the mean renal papillary attenuation value, a statistical significance was achieved (P=0.000).

CONCLUSION

With increasing renal papillary HU values, the risk of recurrent calcium stone disease is increased.

CT urography for the diagnosis of medullary sponge kidney

BACKGROUND

Medullary sponge kidney (MSK) is characterized by malformation of the terminal collecting ducts and is associated with an increased risk of nephrolithiasis, nephrocalcinosis, urinary tract infections, renal acidification defects, and reduced bone density. It has been historically diagnosed with intravenous pyelography (IVP), which is falling out of favor as an imaging modality. CT urography (CTU) performed with multidetector CT (MDCT) has been shown to create images of the renal collecting system with similar detail as IVP; however, its utility in diagnosing MSK has not been defined.

CASE REPORT

We present the first 15 patients with recurrent symptomatic nephrolithiasis who were evaluated in our renal stone clinic with CTU. Four patients were diagnosed with MSK after visualization of the characteristic radiologic findings.

DISCUSSION

CTU effectively demonstrates the characteristic radiologic findings of MSK including collecting tubule dilatation, medullary nephrocalcinosis, nephrolithiasis, and medullary cysts. Dose reduction protocols can reduce radiation exposure below that associated with conventional IVP. We propose CTU be considered for the diagnosis of MSK.

[Ultrasound and color Doppler applications in chronic kidney disease]

Chronic kidney disease (CKD) encompasses all clinical features and complications during the progression of various kidney conditions towards end-stage renal disease. These conditions include immune and inflammatory diseases such as primary and HCV-related glomerulonephritis; infectious diseases such as pyelonephritis with or without reflux and tuberculosis; vascular diseases such as chronic ischemic nephropathy; hereditary and congenital diseases such as polycystic disease and congenital cystic dysplasia; metabolic diseases including diabetes and hyperuricemia; and systemic diseases (collagen disease, vasculitis, myeloma). During the progression of CKD, ultrasound imaging can differentiate the nature of the renal damage in only 50-70% of cases. Infact, the end-stage kidney appears shrunken, reduced in volume (Ø <9 cm), unstructured, amorphous, with acquired cystic degeneration (small and multiple cysts involving the cortex and medulla) or nephrocalcinosis, but there are rare exceptions, such as polycystic kidney disease, diabetic nephropathy, and secondary inflammatory nephropathies. The main difficulties in the differential diagnosis are encountered in multifactorial CKD, which is commonly presented to the nephrologist at stage 4-5, when the kidney is shrunken, unstructured and amorphous. As in acute renal injury and despite the lack of sensitivity, ultrasonography is essential for assessing the progression of the renal damage and related complications, and for evaluating all conditions that increase the risk of CKD, such as lithiasis, recurrent urinary tract infections, vesicoureteral reflux, polycystic kidney disease and obstructive nephropathy. The timing and frequency of ultrasound scans in CKD patients should be evaluated case by case. In this review we will consider the morphofunctional features of the kidney in all nephropathies that may lead to progressive CKD.

Crossed renal ectopia coexisting with nephrolithiasis in a young Nigerian man

INTRODUCTION

Renal ectopia or ectopic kidney is a congenital anomaly in which one or both kidneys are located in an unusual position. It results from the kidney failing to ascend properly from its origin in the true pelvis. In some cases, one kidney may cross over (crossed renal ectopia) so that both kidneys are on the same side of the body. When a crossover occurs, the two kidneys may grow together and become fused (crossed fused renal ectopia). Renal ectopia is generally uncommon; its coexistence with nephrolithiasis is even rarer. Due to its variable presentations, it is usually discovered incidentally, especially when investigating patients for abdominal pain. Treatment may be conservative when renal function is preserved and no complication is associated.

CASE REPORT

we highlight the unusual occurrence of renal ectopia with nephrolithiasis in a 34 year-old Nigerian businessman who presented to the renal clinic of our hospital with a three-month history of intermittent dull right flank pain radiating to the right groin. Physical examination revealed right lumbar tenderness without guarding. The rest of the examination was unremarkable. An abdominal ultrasound scan done revealed a linear calculus in the right renal collecting system but the left kidney was not visualised. An intravenous urogram (IVU) showed a crossed ectopic kidney with nephrolithiasis. The patient was treated conservatively and his kidney function has remained stable.

CONCLUSION

This case report describes the relatively uncommon finding of crossed renal ectopia associated with nephrolithiasis.

Ultrasonography-guided percutaneous nephrolithotomy for the treatment of urolithiasis in patients with scoliosis

We examined the surgical outcomes of minimally invasive percutaneous nephrolithotomy (MPCNL) in scoliotic patients with complicating urolithiasis. Two patients with scoliosis were hospitalized for MPNCL due to upper tract urolithiasis. Calyx puncture was performed in the prone position under ultrasonographic guidance. The renal access route was established using a set of 8F to 16F dilators, and a transpyelic ballistic lithotriptor was used to fragment the calculi. The stone burdens in the 2 patients were 410 mm(2) and 500 mm(2). The entire operative time was 40 to 70 minutes, and the mean time of establishing percutaneous access was 20 minutes. The calculi were completely removed by single-session pneumatic lithotripsy. The 2 patients recovered from MPCNL uneventfully, and the follow-up radiologic examinations identified no stone residual or recurrence. MPCNL is a minimally invasive modality that is effective and safe for the treatment of urolithiasis in patients with scoliosis.

Nephrolithiasis in medullary sponge kidney: evaluation of clinical and metabolic features

OBJECTIVE

Medullary sponge kidney (MSK) is a disorder characterized by tubular dilation of renal collecting ducts and cystic dilation of medullary pyramids that has been associated with stone disease. The significance of nephrolithiasis and the mechanisms by which it occurs are incompletely understood. We describe clinical and metabolic features of nephrolithiasis in a cohort of patients with MSK.

METHODS

Records were reviewed of 56 patients, all with radiographic diagnosis of medullary sponge kidney and data collected pertaining to presentation, stone events and recurrences, stone composition, and metabolic profile to perform a descriptive study with median 3.7 years follow-up.

RESULTS

Nephrolithiasis was confirmed radiographically in 39/56 patients (69.6%). No patient without evidence of nephrolithiasis developed a stone event, whereas 13/39 (33%) of those with nephrolithiasis developed a recurrent stone event. Stones were composed of calcium oxalate monohydrate, calcium oxalate dihydrate, calcium phosphate apatite, and uric acid. Metabolic profile was obtained for 26 of 39 (67%) stone-forming patients demonstrating abnormalities in 22/26 (84.6%). These included hypercalciuria, 58% (15/26); low urine volume, 35% (9/26); hyperuricosuria, 27% (7/26); hypocitraturia, 19% (5/26); elevated urine sodium, 15% (4/26); and hyperoxaluria, 12% (3/26).

CONCLUSION

Many patients with MSK have no evidence of nephrolithiasis. Among those who do, recurrence is common, and metabolic profile and composition are varied as in the general stone-forming population.

Nephrobronchial fistula complicating neglected nephrolithiasis and xanthogranulomatous pyelonephritis

Nephrobronchial fistula is a rare complication seen in association with renal infections, trauma or stone disease. Xanthogranulomatous pyelonephritis (XGP) is an infectious disease with a potential for fistulization to lung, skin, colon and other organs. We present a case of nephrolithiasis complicated by obstruction leading to pyonephrosis and nephrobronchial fistula, treated successfully by nephrectomy and excision of fistulous tracts. Nephrobronchial fistula, although a rare complication of longstanding renal stone, should be considered when a patient presents with perirenal suppurative process. This clinical case illustrates the natural history of nephro-bronchial fistula and the relevance of early treatment of nephrolithiasis.

(99m)Tc-DTPA diuretic renal scintigraphy in dogs with nephroureterolithiasis

This study evaluated the results of diuretic renal scintigraphy in dogs with urolithiasis. Eighty-three kidneys with nephroureterolithiasis +/- renal pelvis/ureteral dilation were included in the study. Sixty-three kidneys showed a non-obstructive pattern, with a steep drop or gradual downward slope of renal time-activity curve (TAC). Excretion half-time of radiopharmaceutical (T(1/2)) was 3.99 (2.99 to 7.95) min. Three kidneys showed an obstructive pattern, with continuous rise of the TAC and median T(1/2) of -10.71 (-5.20 to -17.56) min. Fifteen kidneys had non-diagnostic studies characterized by flat TAC. Individual kidney glomerular filtration rate was <0.5 mL/min/kg body weight in most non-diagnostic studies. Diuretic renal scintigraphy appears to be a useful adjunct modality to rule out or confirm ureteral obstruction in dogs. Additional diagnostic procedures may be necessary to achieve a definitive diagnosis in cases of severely impaired renal function.

[Nephrolithiasis: choice of optimal treatment]

As shown by the results of 113 percutaneous operations for nephrolithiasis, percutaneous nephrolithotomy with lithoextraction is effective in dense, large, multiple, and in some cases, in stag-horn concrements. This operation is a method of choice. Mean duration of the operation is 38.3 +/- 3.8 min, hospital stay is 9.4 +/- 1.6 days.

[Modified percutaneous nephrolithotripsy as monotherapy in stag-horn nephrolithiasis with complex stereometric configuration]

Percutaneous nephrolithotripsy (PN) was used as monotherapy in modification with one additional nephroscopic approach in surgical treatment of 57 patients suffering from stag-horn nephroliths with complicated stereometric configuration. According to classification of stag-horn concrements, C3 and C4 groups comprised 36 (63.1%) and 21 (36.9%) patients, respectively. The greater part of the stone was removed through a standard percutaneous approach regarding the angle of a rigid nephroscope, the other part of the concrement was evacuated through an additional transcutaneous approach for a small-diameter nephroscope. A mean duration of the operation was 60-150 min. The internal stent-catheter was not installed. Residual concrements were detected in 2 (5.6%) and 4 (19%) cases, in C3 and C4, respectively. The presence of residual fragments is explained by complicated stereometric configuration, high density of the concrements, technical difficulties in surgical intervention. As in such cases residual fragments were clinically significant, they were destroyed ub fragments and eliminated according to the "second look" technique in early postoperative period (day 3-4) through nephrostomic fistulas. All the patients were discharged from the hospital in satisfactory condition on postoperative day 5-9. This modification has advantages: one-stage removal of the stone, low invasiveness and traumatism.

Clinical relevance of urate nephrolithiasis in bottlenose dolphins Tursiops truncatus

Few cases of nephrolithiasis (renal calculi) have been reported in bottlenose dolphins Tursiops truncatus. A case-control study was conducted to compare ultrasonographic images and clinicopathologic serum and urine values among 14 dolphins with nephrolithiasis (mild cases: 1 to 19 nephroliths, n = 8; advanced cases: > or = 20 nephroliths, n = 6) to 6 controls over an 18 mo period. Archived nephroliths collected postmortem from 7 additional bottlenose dolphins were characterized using quantitative analysis. All advanced cases had bilateral nephroliths, and 67% had visible collecting ducts. During the study, 2 of the advanced cases developed hydronephrosis, and 1 of these cases had ureteral obstruction due to a nephrolith. Compared to controls, cases (mild and advanced) were significantly more likely to have anemia (hematocrit [HCT] < 38%), high blood urea nitrogen (>59 mg dl(-1)), high creatinine (>1.9 mg dl(-1)), and low estimated glomerular filtration rate (<150 ml min(-1) 2.78 m(-2)). Advanced-case urine samples were more likely to have erythrocytes, occult blood, and lower pH compared to mild cases and controls. Mean serum uric acid among all study groups was low (0.15 to 0.27 mg dl(-1)). Urinary uric acid concentrations were highest among mild cases (272 mg g(-1) creatinine), but advanced cases had levels lower than that of controls (40 and 127 mg g(-1) creatinine, respectively). All nephroliths were characterized as 100% ammonium acid urate. We conclude that nephrolithiasis is clinically relevant in dolphins and can decrease renal function and HCT. The presence of nephrolithiasis, presumably ammonium acid urate nephrolithiasis, in the face of low serum uric and relatively low urinary uric acid in advanced cases may indicate a metabolic syndrome similar to that reported in humans.

Risks of repeated visits for uninvestigated dyspepsia in three community hospitals of Khon Kaen, Thailand

BACKGROUND

Uninvestigated dyspepsia (UD) is common and only 26.4% of these are peptic ulcer disease, while 50% are non-ulcer dyspepsia. A recent study found that nephrolithiasis with urinary tract infection may have the dyspeptic symptoms.

OBJECTIVE

The authors searched for any associations between repeated UD and pyuria, hematuria and other factors.

MATERIAL AND METHOD

A case-control study was performed. It consisted of 489 patients with repeated UD who had visited community hospitals for at least two times per year and 489 controls sampled from the data of the subjects, free of dyspeptic symptoms, from the multi-stage random survey for subjective health complaints in the same province. Multivariate logistic regression models were used for case-control comparisons.

RESULTS

By logistic regression analysis, UD was significantly associated with problems caused by purine-rich foods (PRFs), chronic fatigue, flank paresthesia, hematuria, myofascial pain, and pyuria. The respective adjusted odds ratios and 95% confidence interval (CI) were: 6.67 (4.58, 9.68), 5.06 (3.46, 7.40), 3.98 (2.41, 6.60), 2.97 (2.01, 4.38), 1.91 (1.32, 2.76) and 1.58 (1.01, 2.45). The variables of age (> 48), sex, dysuria, poly-arthralgia, headache and back pain were not significantly associated with UD. The foods that aggravated UD were bamboo shoots, fermented rice noodles, beef alcohol and insects. The rate of pyuria and hematuria was significantly increased with the number of visits within a year [p-value (Chi-square for trend), 0.015 and 0.032].

CONCLUSION

These findings indicate that pyuria, hematuria, and purine-rich foods were associated with repeated hospital visits for dyspepsia.

Anatomical alterations in patients with nephrolithiasis

INTRODUCTION

Nephrolithiasis is a multifactorial disease related to genetic disorders and environmental factors. Kidney stones are more common in adults and are associated with several metabolic and anatomical disorders. The major anatomical abnormalities, such as obstruction of the ureteropelvic junction, horseshoe kidney, complete or incomplete duplicated ureter, bifid pelvis, and medullary sponge kidney, are known to be responsible for stone formation. The objective of this study is to evaluate anatomical alterations in patients with nephrolithiasis in our region.

METHODS

Retrospective study on 1,378 patients with evidence of recent formation of kidney stones. Laboratory investigation and chemical analysis were performed when stones were available. Renal imaging techniques comprised at least renal ultrasound and excretory urography.

RESULTS

Of the 1,378 patients with nephrolithiasis cared for, only 367 (26.5%) (mean age, 36.8 ± 4.3 years) underwent anatomical investigation, of whom 198 (54.5%) were females. At least one anatomical alteration was found in 132 (36%) patients, the most common being renal cyst, completely or incompletely duplicated ureter, and obstruction of the ureteropelvic junction.

CONCLUSIONS

Anatomical alterations were found in 36% of the investigated patients. Renal cyst, ureteral duplication, and obstruction of the ureteropelvic junction were the most frequently found anatomical alterations in the group.

Effect of medical management on recurrent stone formation following percutaneous nephrolithotomy

PURPOSE

Percutaneous nephrolithotomy is a commonly used procedure for treatment of large or complex renal calculi. In some instances postoperative residual stone fragments are an unavoidable result. Yet to our knowledge no study has examined the impact of medical management on stone formation in patients with or without residual fragments following percutaneous nephrolithotomy. Thus, we have conducted the first investigation of aggressive medical management following percutaneous nephrolithotomy and its impact on stone formation rates in patients with and without residual fragments.

MATERIALS AND METHODS

A total of 70 patients who underwent percutaneous nephrolithotomy and received counseling regarding selective medical management following a comprehensive metabolic evaluation, were identified. Patients were placed into 4 groups following percutaneous nephrolithotomy, that is stone-free or residual fragments, who underwent or did not undergo medical therapy. New stone formation was assessed by spontaneous stone passage in the absence of residual stone fragments, stone passage without change in the number of residual fragments, surgical removal of newly formed stones, or appearance of new stones or increase in size of stone or fragments on abdominal radiographs. Stone remission rates were also calculated.

RESULTS

Selective medical therapy significantly decreased stone formation rates in the stone-free (0.67 stones per patient per year vs 0.02) and residual fragment groups (0.67 stones per patient per year vs 0.02) as determined by the Wilcoxon signed rank test (p<0.0001). Moreover, remission was observed in a higher proportion of patients in the medically treated stone-free and residual fragment groups (87% and 77%) when compared to the same groups without medical therapy (29% and 21%, chi-square test p<0.0001).

CONCLUSIONS

Our findings suggest that comprehensive metabolic evaluation and aggressive medical management can control active stone formation and growth in patients with or without residual stone fragments after percutaneous nephrolithotomy. Given the inherent morbidity and increased costs attendant with repeat procedures, medical management should be instituted in patients following percutaneous nephrolithotomy without regard to stone-free status.

Ceftriaxone associated nephrolithiasis: a prospective study in 284 children

Urinary tract calculi have been reported to account for between 1 in 1,000 and 1 in 7,600 hospital admissions in children in the USA. The annual incidence of urolithiasis in patients older than 10 years is 109 per 100,000 of the population in men and 36 per 100,000 of the population in women in Minnesota. The use of various medications is considered to be one of the etiologic factors of nephrolithiasis. Ceftriaxone is a widely used third-generation cephalosporin that is generally considered very safe, but complications such as biliary pseudolithiasis, and rarely, nephrolithiasis have been reported in children. There is limited information about urolithiasis as a side effect of ceftriaxone. The aim of this study was evaluation of the incidence of nephrolithiasis following ceftriaxone therapy in children. This quasi-experimental before and after study was conducted in Mofid Children's Hospital between 2003 and 2005. All patients were treated with 75 mg/kg intravenous ceftriaxone. Diagnosis of pyelonephritis was based on standard criteria. The first renal ultrasonography was performed on the first or second day of admission and was repeated on the last day of treatment. We also evaluated complicated patients for the third time with renal ultrasonography 3 months after treatment. Stone-forming patients underwent metabolic kidney stone risk factor evaluation. We evaluated 284 patients with pyelonephritis, 185 girls and 99 boys. The first ultrasonography was normal in all of our patients. On the second ultrasonography renal stones were reported in 4 out of 284 cases (1.4% and CI=0.96-1.83%). Underlying metabolic risk factors could not be identified in stone-forming patients. Follow-up ultrasonography 3 months later was normal. The results of our study suggest that ceftriaxone-treated patients may be at an increased risk of kidney stone formation. Stones passed spontaneously in all affected patients so the use of this effective drug can be safely continued. Close monitoring of ceftriaxone-treated patients with regard to kidney stone formation is recommended.

The learning curve in the training of percutaneous nephrolithotomy

OBJECTIVES

To investigate the learning curve in the training of percutaneous nephrolithotomy (PCNL).

METHODS

A total of 104 PCNL cases were included in this evaluation to define the learning curve of a surgeon with no previous experience at performing solo PCNL. Two parameters of expertise were reviewed, namely the operation and fluoroscopic screening times. The operation time was calculated as the beginning of access with the needle until the nephrostomy tube was placed and secured. PCNL procedures were analyzed in seven sets of 15 cases regarding the operation and fluoroscopy times, stone size, stone clearance rate, blood transfusion rate, and estimated blood loss.

RESULTS

The mean operation time was 2.4 h for the first 15 patients. It decreased to a mean of 1.5 h for cases 46 through 60. No further decrease in the operation time was observed after case 60. The fluoroscopic screening time was a peak of 17.5 min in the first 15 cases, whereas it dropped to a mean of 8.9 min for cases 46 through 60. The decline in the mean fluoroscopy screening time continued in cases 61 to 104, but the decline was not significant. There was no significant difference in stone size, stone clearance rate, blood transfusion rate, and estimated blood loss among each set of cases.

CONCLUSIONS

This study suggests that the surgical competence in PCNL can be reached after 60 cases. PCNL and fluoroscopy times drop to a steady-state level after performing 60 procedures.

Role of Helical Nonenhanced Computed Tomography in the Evaluation of Acute Flank Pain

OBJECTIVE

To evaluate the role of helical nonenhanced computed tomography (NECT) in the diagnosis of acute flank pain.

METHODS

Seventy-five consecutive patients were analysed retrospectively for profile, loin pain, urine analysis and NECT findings. Diagnostic accuracy of NECT for urolithiaisis was calculated. The value of combined microhaematuria and NECT in the diagnosis of flank pain was also highlighted. The potential for identifying phleboliths and alternative diagnoses on NECT was also explored.

RESULTS

There were 46 males and 29 females with an average age of 42.2 years. Forty-four patients presented with acute left flank pain. NECT carries a sensitivity and specificity of 96% for the diagnosis of stone disease. Combined with microhaematuria, NECT has 100% accuracy in picking up urinary tract stones.

CONCLUSION

NECT is the first imaging investigation of choice for the evaluation of patients presenting to the emergency department with flank pain and suspected renal colic.