Lunedì, 24 Gennaio, 2011

Urine Calcium: Laboratory Measurement and Clinical Utility

Kevin F. Foley, PhD, DABCC; Lorenzo Boccuzzi, DO

Laboratory Medicine. 2010;41(11):683-686. © 2010 American Society for Clinical Pathology


Urine calcium measurement is a commonly ordered test in clinical laboratories. Unlike other urine markers, the utility of urine calcium is less clear to many laboratorians and physicians. Urine calcium can be used to assess parathyroid disease and familial hypocalciuric hypercalcemia (FHH). Although not predictive of stone formation, urine calcium is frequently elevated in patients with lithiasis. The primary clinical value of urine calcium measurement is to aid in the differential diagnoses of patients and direct optimal treatment options for patients with abnormal serum calcium.

Shockwave Lithotripsy Preferred to Ureteroscopy for Single, Distal Ureteric Stones

Laurie Barclay, MD

BJUI. 2010;106:1748-1752.

November 19, 2010 — Extracorporeal shockwave lithotripsy (ESWL) was better than ureteroscopy (URS) as first-line therapy for patients with single, distal ureteric stones, according to the results of a prospective, randomized study reported in the December issue of BJUI.

“ESWL and URS are both accepted treatments for distal ureteric stones, but there is a lot of discussion about which surgical technique should be used as a first-line strategy for this condition,” senior author Vincenzo Mirone, MD, from University Federico II of Naples, in Italy, said in a news release. “Approximately one in three adults with kidney stones will have a distal ureteric stone at some point in their lives. Most stones with a diameter of up to 0.5cm will be expelled spontaneously when the patient urinates without requiring any active intervention. For larger stones that get stuck in the ureter, spontaneous expulsion is very difficult and requires active intervention.”

The study goal was to compare ESWL and URS as first-line therapy in 273 patients with single, monolateral, radiopaque, distal ureteric stones 0.5 to 1.5 cm in size.

Patients were randomly assigned to undergo ESWL (n = 137) with an electromagnetic Modulith SLX lithotripter (Storz Medical) or URS (n = 136) with a semi-rigid ureteroscope. Most (98%) of ESWL treatments were done on outpatients, and none of the patients needed anesthesia or sedation, whereas 96% of URS treatments were done on inpatients, with 22% of patients receiving general anesthesia, 66% receiving local anesthesia, and 12% receiving sedation only.

Both groups were similar in terms of clinical factors, including average age (50 years) and male:female ratio (~1:1). Outcomes were overall stone-free rates (SFRs), rates of repeat treatment, need for additional procedures, and complication rates. Subgroups of patients with stone size of 1 cm or smaller and larger than 1 cm were also analyzed separately.

In the overall ESWL group. SFR was 92.70%, retreatment rate was 44.88%, auxiliary procedure rate was 11.02%, and complication rate was 15.32%. One ESWL session was sufficient in 55% of patients, whereas 31% needed 2 sessions and 13% needed 3 sessions. In the overall URS group, SFR was 94.85%, retreatment rate was 7.75%, auxiliary procedure rate was 18.60%, and complication rate was 19.11%.

Among patients treated with ESWL, those with stones larger than 1 cm had significantly higher need for retreatments and for additional procedures and had higher complication rates. In contrast, for patients with stones 1 cm or smaller, those treated with ESWL had significantly lower rates of retreatment, auxiliary procedures, and complications than those treated with URS.

“Statistical analysis showed no significant differences in overall [SFR], treatment duration, complications and the need for auxiliary procedures,” Dr. Mirone said. “However, there were clear differences in both groups when we divided them into patients with stones of up to 1cm and stones of over 1cm…. These results clearly indicate that ESWL should be the first choice for patients with stones of 1cm and under and URS should be the first choice for patients with stones exceeding 1cm.”

The study authors have disclosed no relevant financial relationships.

Preoperative Stone Attenuation Predicts Lithotripsy Success in Children

Sean McAdams, Nicholas Kim, Daniel Dajusta, Manoj Monga, Indupur R. Ravish, Rajendra Nerli, Linda Baker, Aseem R. Shukla

The Journal of Urology Volume 184, Issue 4, Supplement , Pages 1804-1809, October 2010


Purpose: We determined whether stone attenuation can predict stone fragmentation after shock wave lithotripsy in the pediatric population. Previous studies show that preoperative attenuation in HU on noncontrast computerized tomography predicts shock wave lithotripsy success. To our knowledge study of this parameter in the pediatric population has been lacking to date.

Materials and Methods: We performed a multi-institutional review of the records of 53 pediatric patients 1 to 18 years old who underwent shock wave lithotripsy for 3.8 to 36.0 mm renal calculi. Stone size, average skin-to-stone distance and attenuation value were determined by bone windows on preoperative noncontrast computerized tomography. Success was defined as radiographically stone-free status at 2 to 12-week followup after a single lithotripsy session without the need for further sessions or ancillary procedures.

Results: After lithotripsy 33 patients (62%) were stone-free and 20 had incomplete fragmentation or required additional procedures. Mean ± SD stone attenuation in successfully treated patients vs those with incomplete fragmentation was 710 ± 294 vs 994 ± 379 HU (p = 0.007). Logistical regression analysis revealed that only attenuation in HU was a significant predictor of success. When patients were stratified into 2 groups (less than 1,000 and 1,000 HU or greater), the shock wave lithotripsy success rate was 77% and 33%, respectively (p <0.003).

Conclusions: Stone attenuation less than 1,000 HU is a significant predictor of shock wave lithotripsy success in the pediatric population. This finding suggests that attenuation values have a similar predictive value in the pediatric population as that previously reported in the adult population.

Editorial – The effect of restrictive bariatric surgery on urinary stone risk factors

Semins MJ, Asplin JR, Steele K, Assimos DG, Lingeman JE, Donahue S, Magnuson T, Schweitzer M, Matlaga BR

Urology. 2010 Oct;76(4):826-9 – 10.1016/j.urology.2010.01.037


Objectives: Malabsorptive bariatric procedures such as Roux-en-Y gastric bypass (RYGB) place patients at risk for developing kidney stones. Stone risk factors after purely restrictive procedures such as gastric banding and sleeve gastrectomy are not well characterized. Therefore, we performed a study to examine urinary risk factors of patients who underwent restrictive gastric surgery for bariatric indications.

Methods: A total of 18 patients were enrolled in the study; 14 underwent gastric banding and 4 underwent sleeve gastrectomy. All subjects collected 24-hour urine specimens; at least 6 months had elapsed between surgery and urine collection. Standard stone risk parameters were assessed, and comparisons were made with a group of normal adult nonstone-formers, routine stone-formers, and RYGB bariatric surgery subjects.

Results: Urinary oxalate excretion of the restrictive cohort was significantly less than the RYGB cohort (35.4 vs. 60.7 mg/d; P <.001) and not significantly different from that of the normal subjects (32.9 mg/d; P = .798) and routine stone-formers (37.2 mg/d; P = .997). There were no other significant differences in urinary parameters.

Conclusions: Restrictive bariatric surgery does not appear to be associated with an increased risk for kidney stone disease. In particular, urinary oxalate levels were significantly less than those of RYGB subjects and not significantly different from routine stone-formers and nonstone-forming controls.

Copyright © 2010 Elsevier Inc. All rights reserved.

Nephrolithotomy Superior to Lithotripsy for Asymptomatic Kidney Stones

From Reuters Health Information

J Urol 2010;183:1424-1428.

NEW YORK (Reuters Health) Mar 29 – When asymptomatic lower pole renal calculi require intervention, percutaneous nephrolithotomy provides a higher stone-free rate than shock wave lithotripsy, and with less scarring, Turkish researchers report.

In the April Journal of Urology, they note that asymptomatic caliceal stones require intervention within five years in more than half of cases. To compare treatments and expectant management, Dr. Ahmet Tefekli from Haseki Teaching and Research Hospital in Istanbul and colleagues randomized 94 patients to receive nephrolithotomy, lithotripsy, or observation.

They evaluated patients’ stone status with non-contrast abdominal computed tomography, and they monitored for renal scarring with dimercapto-succinic acid scintigraphy.

All 31 subjects in the nephrolithotomy group were stone free at 12 months. One patient (3.2%) had scarring at 3 months.

With lithotripsy, however, only 19 of 31 patients (61.3%) were stone free at 12 months, and five patients (16.1%) had renal scarring.

Over an average of 20 months, 7 (18.7%) of 32 patients in the observation group required intervention, and one (3.1%) spontaneously passed the stone. No patient in the observation group had renal scarring.

“Patients with asymptomatic lower caliceal stones must be informed in detail about all management options, especially focusing on percutaneous nephrolithotomy with its outstanding outcome,” the authors conclude.

They add that these results “must be further evaluated by comparison with new digital flexible ureterorenoscopy devices.”

J Urol 2010;183:1424-1428.

Reuters Health Information © 2010

Urine Crystals in a 1-year-old Male

Justin Fender, BS; Monte S. Willis, MD, PhD; Yuri Fedoriw, MD

Laboratory Medicine. 2010;41(7):388-392


Clinical History

Patient: A 1-year-old Latino male. Chief Complaint: Vomiting and fever of 39.8°C for 24 hours, pain with urination.

Chief Complaint: Vomiting and fever of 39.8°C for 24 hours, pain with urination.

History of Present Illness: The patient presented to the emergency department with his mother, who reported that he had a fever along with vomiting and trouble urinating for the past 24 hours. The mother denied that the patient had shown signs of ear pain, eye irritation, nasal discharge, congestion, or sore throat. She also did not report a cough, difficulty breathing, diarrhea, bloody stools, skin rash, or decreased urine output. The patient has had no known contact with any sick individuals. At presentation, the patient is not on any medications and has no known drug allergies.

Past Medical History: Product of term vaginal delivery. No birth complications. Immunization status is up-to-date.

Social History: The patient and his mother moved to North Carolina from Mississippi in 2008 and do not have a primary pediatrician. His mother is his primary care giver, and he attends daycare.

Family History: No known family history of kidney stones, abnormal endocrine disorders, or hypercalcemia.

Principal Laboratory Findings: Table 1

Physical Exam

Vital Signs: Heart rate, 118 bpm; respiratory rate, 22 per minute.

General: Active, alert, in no acute distress.

Height: 50th percentile.

Weight: 70th percentile.

Eyes: No lid lag, proptosis, periorbital swelling, or photophobia.

Neck: Supple, no masses.

Lungs: No respiratory distress; clear to auscultation bilaterally.

Heart: Regular rate and rhythm without murmurs.

Extremities: Unremarkable.

Skin: No rash, warm, dry.

Additional Testing: A urine organic acid profile showed increased lactic, 3-OH butyric, acetoacetic, ethylmalonic, and dicarboxylic acids. The patient was discharged prior to additional urine testing.

Stone-Targeted Dual-Energy CT: A New Diagnostic Approach to Urinary Calculosis

Giorgio Ascenti1, Carmelo Siragusa2, Sergio Racchiusa1, Isidora Ielo2, Giambattista Privitera1, Federica Midili2 and Silvio Mazziotti1

1 Department of Radiological Sciences, University of Messina, Policlinico “G. Martino,” Via Consolare Valeria 1, 98100 Messina, Italy.

2 Medical Physics and Radiation Protection Unit, University of Messina, Policlinico “G. Martino,” Messina, Italy.

AJR 2010; 195:953-958 – DOI:10.2214/AJR.09.3635


Objective. The objective of our study was to assess a stone-targeted low-dose protocol for the detection and characterization of urinary tract stones using a dual-energy CT scanner.

Subjects and methods. Thirty-nine patients (20 men, 19 women; age range, 22–87 years; average age, 47 years) with suspected renal colic in which ureteral stones were shown at low-dose unenhanced CT were enrolled in the study. Stone composition could be established in 24 patients, and these patients represent our study population regarding the CT characterization of stones. All examinations were performed with a preliminary low-dose unenhanced CT acquisition of the whole urinary system that was immediately followed by a limited (scanning length, 5 cm) dual-energy acquisition of the region containing the ureteral stone. Stone characterization was assessed using a dual-energy software tool available on the system. Two experienced radiologists who were blinded to the chemical composition of the stones retrospectively reviewed images and analyzed data to determine the composition of the stones. Their results were compared with the biochemical analysis results obtained by stereomicroscopy and infrared spectrometry.

Results. Based on in vitro–measured data, our combined protocol reduced dose by up to 50% compared with a full dual-energy acquisition; in addition, the calculated radiation doses of our protocol in patients are comparable to those of low-dose single- and dual-energy protocols. In 24 patients, 24 ureteral stones considered to be responsible for symptoms and detected at low-dose unenhanced CT were also shown at dual-energy CT. Correct chemical composition was obtained by dual-energy analysis in all 24 ureteral calculi regarding the characterization of uric acid (n = 3), calcium salt (n = 18), and combined uric acid–calcium salt (n = 3) stones.

Conclusion. The use of dual-energy CT attenuation values made it possible to characterize all ureteral calculi, discriminating uric acid stones from calcium salt stones. The increment in radiation exposure due to contemporary scanning with two tubes at different energy levels can be substantially reduced using a limited stone-targeted dual-energy protocol.

Keywords: dual-energy CT • dual-source CT • radiation dose • urinary calculosis • urinary tract stones • urolithiasis

The role of salt abuse on risk for hypercalciuria

Patricia CG Damasio , Carmen RPR Amaro , Natalia B Cunha , Ana C Pichutti , Jose Goldberg , Carlos R Padovani and Joao L Amaro

Nutrition Journal 2011, 10:3doi:10.1186/1475-2891-10-3


Elevated sodium excretion in urine resulting from excessive sodium intake can lead to hypercalciuria and contribute to the formation of urinary stones. The aim of this study was to evaluate salt intake in patients with urinary lithiasis and idiopathic hypercalciuria (IH). Methods: Between August 2007 and June 2008, 105 lithiasic patients were distributed into 2 groups: Group 1 (n=55): patients with IH (urinary calcium excretion > 250mg in women and 300mg in men with normal serum calcium); Group 2 (n=50): normocalciuric patients (NC). Inclusion criteria were: age over 18 years, normal renal function (creatinine clearance [greater than or equal to] 60 ml/min), absent proteinuria and negative urinary culture. Pregnant women, patients with intestinal pathologies, chronic diarrhea or using corticoids were excluded. The protocol of metabolic investigation was based on non-consecutive collection of two 24-hour samples for dosages of: calcium, sodium, uric acid, citrate, oxalate, magnesium and urinary volume. Food intake was evaluated by the three-day dietary record quantitative method, and the Body Mass Index (BMI) was calculated and classified according to the World Health Organization (WHO). Sodium intake was evaluated based on 24-hour urinary sodium excretion. Results: The distribution in both groups as regards mean age (42.11 +/- 10.61 vs. 46.14 +/- 11.52), weight (77.14 +/- 16.03 vs. 75.99 +/- 15.80), height (1.64 +/- 0.10 vs. 1.64 +/- 0.08) and BMI (28.78 +/- 5.81 vs. 28.07 +/- 5.27) was homogeneous. Urinary excretion of calcium (433.33 +/- 141.92 vs. 188.93 +/- 53.09), sodium (280.08 +/- 100.94 vs. 200.44 +/- 65.81), uric acid (880.63 +/- 281.50 vs. 646.74 +/- 182.76) and magnesium (88.78 +/- 37.53 vs. 64.34 +/- 31.84) was significantly higher in the IH group (p<0.05). There was no statistical difference in calcium intake between the groups, and there was significantly higher salt intake in patients with IH than in NC. Conclusions: This study showed that salt intake was higher in patients with IH as compared to NC.

Single session cystolitholapaxy and PCNL for encrusted DJ stent with large associated stone burden

Mario Ferruti, Stefano Paparella, Gabriele Cozzi, Isabella Oliva, Elisabetta Finkelberg, Augusto Maggioni, Francesco Rocco

Urologia – 2010; 77: 267 – 270 – DOI 10.5301/RU.2011.6236


Introduction. Ureteral stent use is commonplace in urology to prevent or relieve ureteral obstruction. If ureteral stents are neglected, they can cause severe morbidity due to migration, occlusion, encrustation, breakage, stone formation, and even death, due to life-threatening urosepsis or complications related to operative intervention. Extracorporeal shockwave lithotripsy, ureterorenoscopy, electrohydraulic lithotripsy, laser lithotripsy, and percutaneous nephrolitholapaxy (PCNL) have been reported for forgotten ureteral stent management, but currently there are no guidelines for this challenging situation and only few algorithms have been introduced by some studies.

Methods. We present a case of a man presenting with an encrusted left double J (DJ) stent, inserted two years before, and bulky radiolucent lithiasis at both ends of the stent. The patient was studied with intravenous pyelogram and non contrast-enhanced computed tomography, and then treated with cystolithotripsy and PCNL in a single session.

Results. Complete clearance of the stones was obtained and the DJ stent was removed without breaking from the percutaneous access.?

Conclusions. Neglected stents still represent a challenge in urology: while endourology remains the best option for treatment, the management of ureteral stents should be based on follow-up and prevention, using for example a computerized warning and stent retrieval software system

Extracorporeal shock wave lithotripsy in the treatment of pediatric urolithiasis: a single institution experience

Konstantinos N. Stamatiou, Ioannis Heretis, Dimitrios Takos, Vaios Papadimitriou, Frank Sofras

International Braz J Urol  - Vol. 36 (6): 724-731, November – December, 2010 – doi: 10.1590/S1677-55382010000600011


Purpose: To compare the efficacy and safety of the electromagnetic lithotripter in the treatment of pediatric lithiasis to that of the earlier electrohydraulic model.

Materials and Methods: Two groups of children with lithiasis aged between 10 and 180 months who underwent extracorporeal shock wave lithotripsy (ESWL). In the first group (26 children), ESWL was performed by using the electrohydraulic MPL 9000X Dornier lithotripter between 1994 and 2003 while in the second group (19 children) the electromagnetic EMSE 220 F-XP Dornier lithotripter was used from April 2003 to May 2006.

Results: In the first group, 21/26 children (80.7%) were stone free at first ESWL session. Colic pain resolved by administration of an oral analgesic in 6 (23%), brief hematuria (< 24 h) resolved with increased fluid intake in 5 (19.2%), while slightly elevated body temperature (< 38°C) occurred in 4 (15.3%). Four children (15.3%) failed to respond to treatment and were treated with ureteroscopy. In the second group 18/19 children were completely stone free at first ESWL session (94.7%). Complications were infrequent and of minor importance: colic pain treated with oral analgesic occurred in 1 (5.26%), brief hematuria (< 24 h), resolved with increased fluid intake in 4 (21%) and slightly elevated body temperature (< 38°C) monitored for 48 hours occurred in 6 (31.5%). Statistical analysis showed that electromagnetic lithotripter is more efficacious and safer than the earlier electrohydraulic model.

Conclusions: Technological development not only has increased efficacy and safety of lithotripter devices in treating pediatric lithiasis, but it also provided less painful lithotripsy by eliminating the need for general anesthesia.

Key words: lithiasis; children; treatment; ESWL; efficacy; complications

Int Braz J Urol. 2010; 36: 724-31

Prognostic factors of spontaneous expulsion in ureteral lithiasis

Sáenz Medina J, Alarcón Parra RO, Redondo González E, Llanes González L, Crespo Martínez L, Fernández Montarroso L, Durán Poveda M, Páez Borda A.

Actas Urol Esp. 2010 Nov;34(10):882-7.


Medical treatment, extracorporeal shock wave lithotripsy (ESWL) and ureteroscopy are therapeutic options for ureteral stones. EWSL and endoscopic treatment of ureteral stones have a high success rate. However it has surgical as well as anaesthetic risks. For many patients, a medicinal treatment without invasive procedures is an option. Watchful waiting does not always result in stone clearance and may be associated with recurrent renal colic. The study of the prognostic factors for expulsion and the medical therapy will help us to select candidates for medical expulsive treatment.

Objectives: To evaluate the characteristics of the stones and the medication administered (alpha blockers, NSAIDs or a combination of both) as predictors of spontaneous passage of the stone.

Material and methods: A retrospective observational study of 260 patients with 278 ureteral stones was conducted. Primary endpoint was stone expulsion. Univariate and multivariate analysis were conducted testing the effect of stone location, size and composition, and medication (alpha-blockers, NSAIDs, or combination) on stone clearance.

Results: 34,2% of the stones studied were spontaneously eliminated. Stone location (pelvic ureter, OR=1.823, p=0.013), size (>5 mm, OR=3.37, p>0.02), and medication (combination of alpha blockers and NSAIDs, OR=8.70, >0.001) were predictors of spontaneous clearance. Multivariate analysis confirmed size (p=0.006) and medication (p>0.001) as independent predictive factors.The use of the combination of NSAIDs and alpha-blockers versus observation multiplied times 8.21 (95%CI 3.37-20.01) the possibilities of spontaneous expulsion.

CONCLUSIONS: Size of stone and medication were confirmed as independent factors for spontaneous expulsion of ureteral stones.

Renal lithiasis in patients with primary hyperparathyroidism. Evolution and treatment.

Valle Díaz de la Guardia F, Arrabal Martín M, Arrabal Polo MA, Quirosa Flores S, Miján Ortiz JL, Zuluaga Gómez A.

Arch Esp Urol. 2010 Jan;63(1):41-2.


Objectives: The relationship between hyperparathyroidism and lithiasis is quite known, so the study of parathyroid glands is especially mandatory in the face of relapses. Our objective is to analyze both primary hyperparathyroidism (PHPT) associated with renal lithiasis and the evolution of this condition after parathyroidectomy, as well as to study factors associated with the presence of lithiasis or bone pathology, and carry out a review on bibliography.

Methods: We describe a retrospective study of a series comprising 287 cases of hyperparathyroidism: 237 of them were primary and the remaining 50, secondary. We have included: sex, age, evolution time and symptoms, diagnostic tests (biochemical, radiological and histological). Factors such as number of episodes prior to diagnosis and treatments were analyzed in patients with symptomatic lithiasis to know whether patients exhibited residual lithiasis after the management of calculi or whether patients underwent episodes after parathyroidectomy, or whether or not they were treated. Statistical analysis was carried out through SPSS 15.0 for Windows.

Results: Forty five percent of the patients had suffered lithiasis episodes; 50%, osteopenia/osteoporosis; 23%, musculoskeletal pain; 23%, asthenia and/or depressive syndrome. In 13.5% of cases, diagnosis was supported by the presence of hypercalcemia; no other symptoms were detected. We have analyzed factors that favor or inhibit renal lithiasis formation and compared biochemical parameters from the group of primary hyperthyroidism that exhibited lithiasis (41 patients) with those patients who did not (49). We noted that lithiasis patients showed higher values of calcium, alkaline phosphatase, intact PTH, mean PTH, osteocalcin, and chlorine/phosphate, calciuria and phosphaturia indexes. Student’s t test on two independent samples revealed significant statistical differences in calcium levels (p<0.05), intact PTH (<.05) and osteocalcin.

Conclusions: Primary hyperparathyroidism patients with lithiasis presented higher values of parathormone, alkaline phosphatase, osteocalcin, and Cl/P and calciuria indexes than lithiasis-free PHPT patients. These patients exhibit objective improvement of symptoms after parathyroidectomy, and rarely a recurrence of lithiasis, a factor that generally coincides with persistence of residual lithiasis.



10° Congresso Nazionale IEA
3-5 Marzo 2011
EAU 2011 Annual meeting
18-22 Marzo 2011
2nd International EAU-EULIS Comprehensive Urolithiasis Workshop
Sofia (Bulgaria),
28-29 Aprile
AUA 2011 Annual meeting
Washington DC,
14-19 Maggio 2011
XXI Congresso Nazionale SIUrO
22-24 Giugno 2011
IV Congresso Nazionale Club Della Litiasi Urinaria CLU
22-24 Settembre 2011
AURO.IT – Congresso nazionale 2011
15-18 ottobre 2011
84° Congresso Nazionale SIU
23 – 26 Ottobre 2011