I migliori abstracts sulla calcolosi, scelti per voi dal vostro


Marco Puglisi


Advances in Urology Volume 2012 (2012), Article ID 606754, 7 pages doi:10.1155/2012/606754

Recent Developments in Computed Tomography for Urolithiasis: Diagnosis and Characterization

P. D. Mc Laughlin, L. Crush, M. M. Maher, and O. J. O’Connor

Department of Radiology, Cork University Hospital and University College Cork, Cork, Ireland

ABSTRACT

Objective:
To critically evaluate the current literature in an effort to establish the current role of radiologic imaging, advances in computed tomography (CT) and standard film radiography in the diagnosis, and characterization of urinary tract calculi. Conclusion. CT has a valuable role when utilized prudently during surveillance of patients following endourological therapy. In this paper, we outline the basic principles relating to the effects of exposure to ionizing radiation as a result of CT scanning. We discuss the current developments in low-dose CT technology, which have resulted in significant reductions in CT radiation doses (to approximately one-third of what they were a decade ago) while preserving image quality. Finally, we will discuss an important recent development now commercially available on the latest generation of CT scanners, namely, dual energy imaging, which is showing promise in urinary tract imaging as a means of characterizing the composition of urinary tract calculi.


Advances in Urology Volume 2012 (2012), Article ID 813523, 5 pages doi:10.1155/2012/813523

Impact of Residual Fragments following Endourological Treatments in Renal Stones

Cenk Acar1 and Cag Cal2

1 Department of Urology, Faculty of Medicine, Pamukkale University, 20070 Denizli, Turkey
2 Department of Urology, Faculty of Medicine, Ege University, 35100 Izmir, Turkey

Abstract:

Today, shock wave lithotripsy (SWL), percutaneous nephrolithotomy (PCNL), and flexible ureterorenoscopy (URS) are the most widely used modalities for the management of renal stones. In earlier series, treatment success of renal calculi assessed with KUB radiography, ultrasound, or intravenous pyelography which are less sensitive than CT that leads to be diversity of study results in reporting outcome. Residual fragments (RFs) after interventional therapies may cause pain, infection, or obstruction. The size and location of RFs following SWL and PCNL are the major predictors for clinical significant symptoms and stone events requiring intervention. There is no consensus regarding schedule for followup of SWL, PCNL, and flexible URS. Active monitoring can be recommended when the stones become symptomatic, increase in size, or need intervention. RFs <4?mm after SWL and <2?mm after PCNL and flexible URS could be actively monitored on an annual basis with CT. Early repeat SWL and second-look endoscopy are recommended after primary SWL and PCNL, respectively. There is insufficient data for flexible URS, but RFs can be easily treated with repeat URS. Finally, medical therapy should be tailored based on the stone analysis and metabolic workup that may be helpful to prevent regrowth of the RFs.


Advances in Urology Volume 2012 (2012), Article ID 320104, 5 pages doi:10.1155/2012/320104

Management of Clinically Insignificant Residual Fragments following Shock Wave Lithotripsy

Elisa Cicerello, Franco Merlo, and Luigi MaccatrozzoUnità Complessa di Urologia, Ospedale Regionale Ca’Foncello, Treviso, Italy

Abstract:
Management of Clinically insignificant residual fragments (CIRFs) are small fragments (less than 5?mm) that are present in upper urinary tract at the time of regular post-SWL followup. The term is controversial because they may remain silent and asymptomatic or become a risk factor for stone growth and recurrence, leading to symptomatic events, and need further urologic treatment. Although a stone-free state is the desired outcome of surgical treatment of urolithiasis, the authors believe that the presence of noninfected, nonobstructive, asymptomatic residual fragments can be managed metabolically in order to prevent stone growth and recurrence. Further urologic intervention is warranted if clinical indications for stone removal are present.


Advances in Urology Volume 2012 (2012), Article ID 175843, 6 pages doi:10.1155/2012/175843

New Pathophysiological Aspects of Growth and Prevention of Kidney Stones

J. M. Baumann and B. AffolterLaboratories Viollier, Departement of Stone Research, Gartenstrasse 9, 2502 Biel, Switzerland

Abstract:
Kidney stones probably grow during crystalluria by crystal sedimentation and aggregation (AGN) on stone surfaces. This process has to occur within urinary transit time (UT) through the kidney before crystals are washed out by diuresis. To get more information, we studied by spectrophotometry the formation and AGN of Ca oxalate (Ca Ox) crystals which were directly produced in urine of 30 stone patients and 30 controls by an oxalate (Ox) titration. Some tests were also performed after removing urinary macromolecules (UMs) by ultrafiltration. To induce rapid crystallization, high Ox additions (0.5–0.8?mM) were necessary. The most important finding was retardation of crystal AGN by UM. In urine of 63% of controls but only 33% of patients, no AGN was observed during an observation of 60 minutes (P < 0.05). Also growth and sedimentation rate of crystals were significantly reduced by UM. For stone metaphylaxis, especially for posttreatment residuals, avoiding dietary Ox excesses to prevent crystal formation in the kidney and increasing diuresis to wash out crystals before they aggregate are recommended.


Advances in Urology Volume 2012 (2012), Article ID 589038, 4 pages doi:10.1155/2012/589038

Treatment of Kidney Stones Using Extracorporeal Shock Wave Lithotripsy (ESWL) and Double-J Stent in Infants

1 Department of Urology, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari 4813894393, Iran

2 Student Research Committee, Cancer Research Center, Thalassemia Research Center, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari 4813894393, Iran

Abstract:

Background.

Extracorporeal shock wave lithotripsy (ESWL) has progressively acquired popularity as being the gold standard treatment for upper urinary tract lithiasis in infants since 1980. Our aim was to evaluate the outcome of ESWL for kidney stones and the use of double-J stent in infants.

Material and Methods.

A prospective clinical trial study performed on 50 infants with renal calculi at pelvic admitted in the Urology ward of Shafa Hospital, Sari, Iran, between 2001 and 2010. Main outcome measure of our study was clearing stones after one or more consecutive sessions of ESWL.

Results.

The study included 50 patients with renal calculi at pelvic. Among them, there were 35 (70%) boys and 15 (30%) girls with the age ranging from 1 to 13 months (mean of 7 month ± 3 days). All of them were treated by standard ESWL using Simons Lithostor plus machine. The stone sizes ranged from 6?mm to 22?mm. Double-J stents were placed in 11 infants (22%) with stones larger than 13?mm. Most of the patients required only one ESWL session.

Conclusion.

Since there were no complications following ESWL treatment, we can conclude that, in short term, ESWL is an effective and safe treatment modality for renal lithiasis in infants. In addition, we recommend double-J stent in infants with stones larger than 13mm.


doi: 10.2214/AJR.11.7276 AJR March 2012 vol. 198 no. 3 603-608

CT-Based Determination of Maximum Ureteral Stone Area: A Predictor of Spontaneous Passage

Shadpour Demehri1, Michael L. Steigner1, Aaron D. Sodickson1, E. Andres Houseman2, Frank J. Rybicki1 and Stuart G. Silverman1

ABSTRACT OBJECTIVE:

The purpose of this study was to test the hypothesis that the maximum axial area of ureteral stones is a more accurate predictor of spontaneous passage than the maximum axial diameter.

MATERIALS AND METHODS:

This study retrospectively reviewed 211 consecutive emergency department patients (mean age, 48.8 years; age range, 18–88 years) with acute flank pain due to ureteral stones diagnosed using unenhanced CT. Measurements of maximum atrial area were obtained using fixed (FTM) and variable (VTM) threshold methods. For the FTM, stones were segmented using an attenuation threshold of 130 HU. For the VTM, stones were segmented using an attenuation threshold determined by one half of individual stone attenuation. Measurements of maximum atrial diameter were obtained using soft-tissue and bone window settings. Receiver operating characteristic (ROC) analysis was used to compare the accuracy of maximum atrial area with maximum atrial diameter measurements for predicting spontaneous passage.

RESULTS:

Fifty-seven patients (27%) required urologic intervention. The areas under the ROC curve (AUC) of maximum atrial area using FTM (0.83, p = 0.013) and VTM (0.84, p = 0.004) were larger than the AUC (0.8, p = 0.4) for maximum atrial diameter using bone window settings or AUC (0.79) for maximum atrial iameter using soft-tissue window settings. For stones with maximum atrial diameter (in soft-tissue window settings) > 5 mm and = 10 mm, the accuracy of maximum atrial area using VTM (AUC = 0.75) and FTM (AUC = 0.74) was superior to the accuracy of maximum atrial diameter in soft-tissue (AUC = 0.67) and bone (AUC = 0.69) window settings (p < 0.05) in predicting spontaneous passage.

CONCLUSION:
Determination of the maximum axial area may improve the accuracy in predicting spontaneous passage of ureteral stones, particularly those between 5 and 10 mm.


European Urology Volume 62, issue 6, pages e95-e106, December 2012

Impact of Case Volumes on the Outcomes of Percutaneous Nephrolithotomy

Dedan Opondo, Ahmet Tefekli, Tarik Esen, Gaston Labate, Kandasami Sangam, Antonello De Lisa, Hemendra Shah, Jean de la Rosette, on behalf of the CROES PCNL study group.

ABSTRACT

Background
Previous studies have demonstrated relationships between case volumes and outcomes in surgery. Little is known about the impact of case volumes on the outcomes of percutaneous nephrolithotomy (PCNL).

Objective
To investigate the influence of case volumes on the efficacy and safety outcomes of PCNL.

Design, setting, and participants
From November 2007 to December 2009, prospective data were collected by the Clinical Research Office of the Endourological Society from consecutive patients over a 1-yr period in 96 centers globally. Data of 3933 patients in the Global PCNL study database were included in this study.

Outcome measurements and statistical analysis
Patients were divided into low- and high-volume groups based on the median annual case volume of their respective treatment center. Preoperative characteristics and outcomes were compared between the two groups. Case volume was treated as a continuous variable. The relationship between case volume and stone-free (SF) rate, complication rate, and duration of hospital stay was explored using multivariate regression analysis.

Results and limitations
SF rates were higher in high-volume centers (82.5% vs 75.1%; p value <0.001). Complication rates were lower in high-volume centers (15.9% vs 21.7%; p value 0.002), whereas the mean (standard deviation [SD]) duration of stay was shorter in high-volume centers (3.4 [2.6] vs 4.9 [3.7] d; p value <0.001). SF rate increased with case volume, whereas complication rate and duration of stay diminished with increasing case volumes after adjusting for stone burden, urine culture status, American Society of Anesthesiologists score, and the presence of staghorn stones. The highest SF rates were observed in centers with >120 cases per year.

Conclusions
Centers that perform high numbers of PCNLs per year achieve better results. Both the efficacy and safety outcomes of PCNL improve with the number of surgeries performed in a given center per year.

Take Home Message
Centers that perform large numbers of percutaneous nephrolithotomies (PCNLs) per year achieve higher stone-free rates and lower complication rates with a shorter duration of hospital stay, suggesting that both efficacy and safety outcomes of PCNL improve with the number of surgeries.


Journal of Endourology. February 2013, 27(2): 162-167. doi:10.1089/end.2012.0470.

Absolute Hounsfield Unit Measurement on Noncontrast Computed Tomography Cannot Accurately Predict Struvite Stone Composition

Giovanni Scala Marchini, Surafel Gebreselassie, Xiaobo Liu, Cindy Pynadath, Grace Snyder, and Manoj Monga.

ABSTRACT:

Background:
The purpose of our study was to determine, in vivo, whether single-energy noncontrast computed tomography (NCCT) can accurately predict the presence/percentage of struvite stone composition.

Methods:
We retrospectively searched for all patients with struvite components on stone composition analysis between January 2008 and March 2012. Inclusion criteria were NCCT prior to stone analysis and stone size =4?mm. A single urologist, blinded to stone composition, reviewed all NCCT to acquire stone location, dimensions, and Hounsfield unit (HU). HU density (HUD) was calculated by dividing mean HU by the stone’s largest transverse diameter. Stone analysis was performed via Fourier transform infrared spectrometry. Independent sample Student’s t-test and analysis of variance (ANOVA) were used to compare HU/HUD among groups. Spearman’s correlation test was used to determine the correlation between HU and stone size and also HU/HUD to % of each component within the stone. Significance was considered if p<0.05.

Results:
Fourty-four patients met the inclusion criteria. Struvite was the most prevalent component with mean percentage of 50.1%±17.7%. Mean HU and HUD were 820.2±357.9 and 67.5±54.9, respectively. Struvite component analysis revealed a nonsignificant positive correlation with HU (R=0.017; p=0.912) and negative with HUD (R=-0.20; p=0.898). Overall, 3 (6.8%) had <20% of struvite component; 11 (25%), 25 (56.8%), and 5 (11.4%) had 21% to 40%, 41% to 60%, and 61% to 80% of struvite, respectively. ANOVA revealed no difference among groups regarding HU (p=0.68) and HUD (p=0.37), with important overlaps. When comparing pure struvite stones (n=5) with other miscellaneous stones (n=39), no difference was found for HU (p=0.09) but HUD was significantly lower for pure stones (27.9±23.6 v 72.5±55.9, respectively; p=0.006). Again, significant overlaps were seen.

Conclusions:
Pure struvite stones have significantly lower HUD than mixed struvite stones, but overlap exists. A low HUD may increase the suspicion for a pure struvite calculus.


Journal of Endourology. -Not available-, ahead of print. doi:10.1089/end.2012.0324.

Holmium: YAG Laser Lithotripsy Versus Pneumatic Lithotripsy for Treatment of Distal Ureteral Calculi: A Meta-Analysis

ABSTRACT:
The objective of this study was to estimate the treatment effect of Pneumatic Lithotripsy (PL) versus holmium: YAG laser lithotripsy (LL) in the treatment of distal ureteric calculi. A bibliographic search covering the period from 1990 to April 2012 was conducted using search engines such as MEDLINE, EMBASE, and Cochrane library. Data were extracted and analyzed with RevMan5.1 software. A total of 47 studies were scant, and 4 independent studies were finally recruited. Holmium: YAG LL conveyed significant benefits compared with PL in terms of early stone-free rate [odds ratio (OR)=4.42, 95% confidence interval (CI) (1.14, 17.16), p=0.03], delayed stone-free rate [OR=4.42, 95%CI (1.58, 12.37), p=0.005], mean operative time [WMD=-16.86, 95%CI (-21.33, -12.39), p<0.00001], retaining double-J catheter rate [OR=0.44, 95%CI (0.25, 0.78), p=0.004], and stone migration incidence [OR=0.26, 95%CI (0.11, 0.62), p=0.003], but not yet in the postoperative hematuria rate and the ureteral perforation rate according to this meta-analysis. Precise estimates on larger sample size and trials of high quality may provide more uncovered outcomes in the future.


Journal of Endourology. -Not available-, ahead of print. doi:10.1089/end.2012.0218.

Supracostal Tubeless Percutaneous Nephrolithotomy: A Retrospective Cohort Study

Brian Duty, M.D.,1 Michael Conlin, M.D.,2 Matthew Wagner, M.D.,2 Aaron Bayne, M.D.,2 Gregory Adams, M.D.,2 and Eugene Fuchs, M.D.2

1Department of Urology, Smith Institute for Urology, Hofstra University, North Shore–Long Island Jewish Health System, New Hyde Park, New York.
2Division of Urology, Oregon Health Science University, Portland, Oregon.

Purpose:
To evaluate the safety of tubeless percutaneous nephrolithotomy in patients undergoing supracostal percutaneous renal access.

Patients and Methods:
Between October 1999 and October 2010, 302 patients underwent percutaneous nephrolithotomy via a supracostal access tract. Two hundred forty-eight (82.1%) patients had a nephrostomy tube placed at the end of the case and 54 (17.9%) did not. The medical records of both cohorts were compared regarding patient demographics (age, sex, body mass index, preoperative creatinine level), operative characteristics (estimated blood loss, length of stay, treatment efficacy), and complication rates (overall, thoracic, hemorrhage necessitating transfusion).

Results:
Patient demographics did not differ between the tubeless and nephrostomy tube groups. Estimated blood loss was significantly less in the tubeless patients (67?mL vs 123 mL; P=0.019). The tubeless group had a shorter mean length of stay than the nephrostomy tube group (2.5 vs 3.4 days, P<0.01). Treatment success was comparable between the two groups (tubeless 81.5% vs nephrostomy tube 77.8%; P=0.553). Overall complication (P=0.765) and blood transfusion (P=0.064) rates were equivalent. Chest complications were higher in the tubeless group (22.2%) compared with the nephrostomy tube patients (10.9%) (P=0.024). Nevertheless, chest complications necessitating intervention were not different (P=0.152).

Conclusions:
Tubeless supracostal percutaneous nephrolithotomy was associated with less intraoperative blood loss and a shorter hospital stay. Although the tubeless group experienced more chest complications overall, the need for intervention was no different among the two cohorts. Tubeless supracostal percutaneous nephrolithotomy appears safe.


Urology Volume 80, Issue 6 , Pages 1192-1197, December 2012

Comparative Study of Outcome in Treating Upper Ureteral Impacted Stones Using Minimally Invasive Percutaneous Nephrolithotomy With Aid of Patented System or Transurethral Ureteroscopy

Zhongsheng Yang, Leming Song, Donghua Xie, Min Hu, Zuofeng Peng, Tairong Liu, Chuance Du, Jiuqing Zhong, Wen Qing, Shulin Guo,
Lunfeng Zhu, Lei Yao, Jianrong Huang, Difu Fan, Zhangqun Ye

ABSTRACT:

Objective
To determine an efficient method for treating upper ureteral impacted stones, we compared the outcome of minimally invasive percutaneous nephrolithotomy with the aid of our patented system and transurethral ureteroscopy.

Materials and Methods
A total of 182 patients with complicated impacted upper ureteral stones above the level of L4 were randomly divided into 2 groups. Group 1 included 91 patients who were treated with minimally invasive percutaneous nephrolithotomy with the aid of a patented system. Group 2 included 91 patients who were treated with ureteroscopy. The patients underwent postoperative shock wave lithotripsy, when necessary. The operative time, stone clearance rate, operative complication markers (amount of intraoperative bleeding and postoperative fever rate), and cost of treatment were compared.

Results
A significantly shorter operative time, greater rate of stone clearance, lower need for postoperative shock wave lithotripsy, and lower rate of postoperative fever was found in group 1 than in group 2 (P <.05). However, the cost of treatment and amount of intraoperative bleeding were significantly greater.

Conclusion
We believe minimally invasive percutaneous nephrolithotomy with the aid of the patented system could be the first choice in treating complicated impacted upper ureteral stones above the level of L4.


Urology Volume 80, Issue 6 , Pages 1198-1202, December 2012

Standardized Flexible Ureteroscopic Technique to Improve Stone-free Rates

Arkadiusz Miernik, Konrad Wilhelm, Peter Uwe Ardelt, Fabian Adams, Franklin Emmanuel Kuehhas, Martin Schoenthaler

ABSTRACT:

Objective
To present a unique completely standardized sequence of steps performed before, during, and after flexible ureteroscopy (FURS) that achieves superior results for FURS treatment of renal calculi.

Materials and Methods
The “Freiburg FURS technique” includes the following steps: (a) preoperative ureteral stenting; (b) placement of 2 hydrophilic wires; (c) semirigid ureteroscopy before FURS; (d) the use of a large access sheath (14F-16F) if multiple ureteral passages are expected; (e) the use of a 2-working channel flexible endoscope; (f) a modified active flushing system; and (g) an advanced holmium laser technique with complete stone extraction. We performed a prospective analysis of 153 consecutive FURS procedures for nephrolithiasis from August 2009 to July 2011.

Results
Data analysis revealed an “immediate” stone-free rate of 96.7% (as confirmed by endoscopy, fluoroscopy, and ultrasonography), a medium of 2.3 stones, and a cumulative stone size of 10.5 mm (range 3-43). The operative time was 67 minutes (range 20-160). The use of an access sheath was required in 71% of the patients and the postoperative use of a double-J stent in 57% of patients. Complications (Clavien grade II and III) developed in 9.1% of patients (including 7 with minimal perforation that required ureteral stenting for 1 month, 3 with secondary flank pain/hydronephrosis requiring double-J stenting and hospitalization, and 4 with fever or urinary tract infections requiring antibiotic therapy. Follow-up examinations after 3 months showed no late complications.

Conclusion
The modified FURS technique provided clinically superior results with a low complication rate. However, the approach requires the use of considerable resources, both technical and surgical and financial.


Urology Volume 80, Issue 6 , Pages 1203-1208, December 2012

Gas-containing Renal Stones: Findings From Five Consecutive Patients

Ted B. Manny,Patrick W. Mufarrij, Jessica N. Lange, Majid Mirzazadeh, Ashok K. Hemal, Dean G. Assimos

ABSTRACT

Objective
To describe the clinical course, microbiology, and metabolic findings of 5 patients presenting to our institution with gas-containing renal stones.

Materials and Methods
During a 20-month period beginning in 2009, 5 patients were identified by computed tomography scanning to harbor gas-containing renal calculi. Despite similar imaging and referral practice patterns, no such cases had been seen at our institution in the preceding 20 years. The records of these patients were reviewed to better characterize this unique condition.

Results
All 5 subjects were premenopausal women. One patient presented with urosepsis and 4 presented with flank pain. All had urinary tract infections, and Escherichia coli was isolated from a voided urine specimen in 3. Stone culture was positive in 2 and was concordant with the voided specimen in 1. The stones were solitary in 4 and multiple in 1 patient. All the stones were composed of calcium phosphate. Of the 5 patients, 3 had pure calcium phosphate stones and 2 had stones with calcium oxalate monohydrate components. Also, 3 subjects had diabetes mellitus, 3 had hypertension, and 1 had a history of gout. Two subjects underwent 24-hour urine metabolic testing, and abnormalities were identified in both. All patients were rendered stone free: 4 with percutaneous nephrostolithotomy and 1 using robotic pyelolithotomy.

Conclusion
Gas-containing renal stones are rare but might be increasing in prevalence. The pathophysiology is unknown but is most likely influenced by a combination of metabolic and infectious factors.