Trends in surgery for upper urinary tract calculi in the USA using the Nationwide Inpatient Sample: 1999-2009

Steerable Ureteroscopic Renal Evacuation (SURE) for Large Renal Stones: A Multi-Institutional Center Study

BACKGROUND

The results of a recent pilot study suggest that steerable ureteroscopic renal evacuation (SURE) is safe and more effective in stone removal than basketing following laser lithotripsy. The objective of this retrospective study was to further assess the safety and efficacy of SURE using the CVAC® Aspiration System (Calyxo, Inc., Pleasanton, CA) in patients with large stone burdens.

MATERIALS AND METHODS

Patients with a baseline stone burden of ≥10 mm who underwent SURE were identified. Subject demographics, secondary procedures, complications, and stone clearance (defined as percent baseline volume reduction) were evaluated. Sub-analyses were performed to explore patients identified as high-risk for percutaneous nephrolithotomy (PCNL) because 1) they were on anticoagulation or antiplatelet therapy at the time of procedure, or 2) they had limited mobility due to neurological conditions.

RESULTS

Identified patients (N=43) had a mean pre-operative stone burden of 29±12 mm and mean stone volume of 3,092±5,002 mm3. Approximately one-half of patients (n=24, 55.8%) had computerized tomography (CT) imaging at follow-up, and of those, eight (33.3%) had no residual stones, 22 (91.7%) had >90% stone clearance, 23 (95.8%) had >80% stone clearance and 24 (100%) had >60% stone clearance. Stone clearance based on baseline stone burden varied between 93.8% and 98.9%. At baseline, 21 patients were anticipated to require staged ureteroscopy; however, only two of those (9.5%) needed secondary procedures. High-risk patients (n=22) were on anticoagulation or antiplatelet therapy (n=12) or had neurologic conditions (n=10). Stone clearance was 97% among patients in the anticoagulated cohort with postoperative CT imaging, and 83% in patients with neurologic conditions. There were no device-related complications and no post-operative admissions.

CONCLUSIONS

The CVAC® Aspiration System is safe and effective for treating large stone burdens, including in high-risk patients, and may decrease the need for PCNL or secondary procedures.

Ureteroscopy in the elderly: safety and functional results

PURPOSE

To evaluate the effectiveness and safety of ureteroscopy (URS) for urinary stones treatment in patients ≥ 80 years of age.

METHODS

From 2012 to 2021, 96 patients ≥ 80 years underwent URS for urinary stone disease. Patients' demographics and surgical outcomes were examined.

RESULTS

The median length of follow-up was 25 months. Median age was 84 years. Half of the patients (53%) were ASA score 3 and 16% ASA 4. Mean stone diameter (SD) was 10.6 mm, and mean procedure time was 78 min. Eighty-three patients underwent follow-up imaging (ultrasonography or computed tomography) with a median time of 31 days. Stone-free rate was 73.9%. Twenty patients (20.7%) experienced a minor complication [Clavien-Dindo (CD) I-II] whereas five (5.7%) experienced a major complication (CD III-V). SD ≥ 10 mm predicted CD III-V complications (OR 1.25, 95% CI 1.01-1.55, p = 0.03). Urinary drainage prior the procedure with double J stent, nephroureteral stent or percutaneous nephrostomy tube had no impact on patients' SFR [74.6% in the drained group versus 64.0% in the undrained group (p = 0.44)] nor on major complications (OR 4.68, 95% CI 0.25-87.77, p = 0.30).

CONCLUSION

In elderly patients, URS for treatment of renal and ureteral stones is a relatively efficient and safe procedure. The risk of major complications is low, and the only associated risk factor found was SD ≥ 10 mm. Urinary drainage prior the procedure did not affect patients' outcomes.

Patient compliance to dietary recommendations: tips and tricks to improve compliance rates

Urinary stone disease continues to be a public health problem with growing incidence and recurrences. Recurrence is nearly detected in 50% of the patients within 5 years after the first episode. However, stone recurrence rates can be reduced to a certain extent. The American Urological Association (AUA) and the European Urological Association (EAU) guidelines advice dietary, fluid intake, and medical treatment to prevent or minimize stone recurrence. However, studies have shown that compliance to dietary and fluid intake recommendations is low. Beside this, nutritional evaluation of the patients is sufficient. Using food frequency questionnaires (FFQs), 24 h recall methods (short, individual-oriented, and easily applicable) or mobile apps can be used. In addition, cooperation with registered dietitians (RD) and planning tailored dietary programmes may have positive effect on compliance. Providers who give dietary advices should improve their knowledge about the topic and communication skills to create a patient-provider trust relationship. Simplifying the advices (shorter lists, applicable advices), spending more time, and giving education until being sure for patients' understanding with regular remindings may improve adherence. Moreover, patients increased awareness and knowledge about dietary advices are beneficial. Smart devices for fluid uptake or urine pH monitoring, mobile apps or web-based portals, and telemedicine applications can be used to maintain the compliance on dietary advices. Compliance with dietary modifications and fluid intake recommendations can be well achieved by individualized evaluation/close follow-up and the elimination of the problems limiting the patient compliance.

Quantification of outflow resistance for ureteral drainage devices used during ureteroscopy

PURPOSE

Since renal pelvis pressure is directly related to irrigation flowrate and outflow resistance, knowledge of outflow resistance associated with commonly used drainage devices could help guide the selection of the type and size of ureteral access sheath or catheter for individual ureteroscopic cases. This study aims to quantitatively measure outflow resistance for different drainage devices utilized during ureteroscopy.

METHODS

With measured irrigation flowrate and renal pelvis pressure, outflow resistance was calculated using a hydrodynamic formula. After placement of a drainage device into a silicone kidney-ureter model, a disposable ureteroscope with a 9.5-Fr outer diameter was inserted with its tip positioned at the renal pelvis. Irrigation was delivered through the ureteroscope from varying heights above the renal pelvis. Renal pelvis pressure was measured directly from the port of the kidney model using a pressure sensor (Opsens, Canada). Outflow resistance was determined by plotting flowrate versus renal pelvis pressure. All trials were performed in triplicate for each drainage device inserted.

RESULTS

Flowrate was linearly dependent on renal pelvis pressure for all drainage devices tested. Outflow resistance values were 0.2, 1.1, 1.4, 3.9, and 6.5 cmH₂O/[ml/min] for UAS 13/15 Fr, UAS 11/13 Fr, UAC 6 Fr, UAC 4.8 Fr, and UAC 4.0 Fr, respectively, across the range of commonly used irrigation flowrates.

CONCLUSIONS

In this study, outflow resistance of different ureteral drainage devices was quantitatively measured. This knowledge can be useful when selecting which type and size of drainage device to insert to maintain safe renal pelvis pressure during ureteroscopy.

Attitudes of urologists on metabolic evaluation for urolithiasis: outcomes of a global survey from 57 countries

Although stone disease is an important health problem with high incidence and recurrence rates, it is a preventable disease. Attitudes and practices of urologists regarding the prevention of recurrence continue to be a subject of debate. In this context, an online survey study was conducted involving 305 urologists from 57 different countries. The first 7 questions collected demographic data about the urologists and the remaining 23 questions were about the recurrence and metabolic evaluation, medical treatment, and follow-up of urinary stone disease. Most urologists (85.2%) thought that metabolic examination was important. Approximately one-third of the participants (34.1%) performed 24-hour urine analysis and stone analysis was ordered by 87.5% of the urologists. Metabolic analysis was performed for all patients by 14.7% of the participants. For pediatric patients this rate was 68.5%, and for adults with recurrence the rate was 81.6%. Reasons cited by the urologists for not performing metabolic analysis included not feeling confident doing so (18.3%), having limited facilities in their hospital (26.5%), having an excessive daily workload (31.8%), patient-related factors (27.5%), and referring patients to other departments for metabolic evaluation (20.9%). Although majority of the responding urologists do consider the metabolic analysis as vital important, they seemed not to be willing to perform these tests with the same degree of enthusiasm in their daily practice. Our results show that urologists need support in performing and interpreting 24-hour urine analysis, improving their knowledge levels, and communicating with patients. Urology residency training should focus more on the prevention of urinary stone recurrence in addition to the surgical training.

Changing Trends in Surgical Management of Nephrolithiasis among Young Adults: A 15-Year Population-Based Study

Background: Increases in obesity and diabetes rates among all ages have led to a greater prevalence of nephrolithiasis worldwide. We aimed to explore the changing trends in surgical management of nephrolithiasis in young adults over a 15 year period. Methods: We reviewed medical records of military personnel for information on the diagnosis and care of nephrolithiasis before and during active service between 2007−2021, divided into three 5 year periods: 2007−2011, 2012−2016, and 2017−2021. Demographic, clinical, radiological, and surgical data were retrieved for the analysis of changing trends. Results: The records of 1,117,692 recruits yielded 7383 (0.66%) with stone-related surgeries, of whom 1885 were operated during military service. Their median age was 19.6 years (interquartile range [IQR] 16.8−21.2), 829 (70%) were males, and the cohort’s median body mass index was 23.6 (IQR 17.3−26.1). There was a dramatic decline in shock wave lithotripsy (SWL) prevalence (35.1%, 10.4%, and 4.4%, respectively) with a continually increasing prevalence of ureteroscopy (URS)/retrograde intrarenal surgery (RIRS) (62.7%, 88.5%, and 94.6%, p = 0.01). Percutaneous nephrolithotomy (PCNL) procedures have become nearly extinct over time (0.8% in 2017−2021). The number of median-sized stones treated by URS/RIRS increased (7.5 mm, 8.2 mm, and 9.7 mm, p = 0.044), but not those treated by SWL/PCNL. The median length of medical leave for URS/RIRS and PCNL decreased significantly (7 vs. 4 days, p = 0.05 and 10 vs. 6 days, p = 0.036, respectively), with no comparable change for SWL. There was a substantial decline in ancillary procedures in the URS/RIRS groups (9%, 6.8%, and 3.1%, p < 0.01), but not in the SWL/PCNL groups. Conclusions: Advancements in technology and surgical training are leading to the extinction of SWL and the adoption of URS/RIRS as the new standard of care for nephrolithiasis among young adults.

Pre- and peri-operative clinical information, physiological observations and outcome measures following flexible ureterorenoscopy (FURS), for the treatment of kidney stones. A single-centre observational clinical pilot-study in 51 patients

BACKGROUND

Kidney stone disease contributes to a significant proportion of routine urological practice and remains a common cause of worldwide morbidity. The main aim of this clinical-pilot study was to investigate the effect of flexible ureterorenoscopy (FURS) on pre- and peri-operative clinical information, physiological observations and outcome measures.

METHODS

Included were 51 patients (31 males, 20 females), who underwent elective FURS, for the treatment of kidney stones. Pre-operative and peri-operative clinical information, and post-operative physiological observations and outcome measures were collected using a standard case report form. Pre-operative clinical information included age, gender, BMI, previous history of stone formation and hypertension. Pre-operative stone information included the size (mm), Hounsfield units (HU), laterality and intra-renal anatomical location. Peri-operative surgical details included surgical time in minutes; Laser use; Duration and energy of laser; and post-operative stenting. The physiological outcomes measured included systolic and diastolic blood pressure (mmHg), Likert pain score, temperature, heart rate (bpm) and respiration rate (bpm). Following initial descriptive analysis, a series of Pearson's correlation coefficient tests were performed to investigate the relationship between surgical factors other variable factors.

RESULTS

A series of significant, positive correlations were observed between; age and surgical time (p = 0.014, r = 0.373); stone size and Hounsfield unit (p = 0.029, r = 0.406); surgical time and duration of laser (p < 0.001, r = 0.702); surgical time and BMI (p = 0.035, r = 0.322); baseline heart rate and Hounsfield unit (p = 0.026, r = - 0.414); base line heart rate and BMI (p = 0.030, r = 0.307).; heart rate at 120-min post FURS and age (p = 0.038, r = - 0.308); baseline pain score and BMI (p = 0.010, r = 0.361); baseline respiration rate and BMI (p = 0.037, r = 0.296); respiration rate at 240-min post FURS and BMI (p = 0.038, r = 0.329); respiration rate at 120 min post FURS and age (p = 0.022, r = - 0.330). Four patients developed post-operative complications (3-UTIs with urinary retention, 1-urosepsis).

CONCLUSIONS

We report that following FURS there is an association between various physiological, clinical and surgical parameters. Although these correlations are weak, they warrant further investigation as these may be linked with untoward complications, such as infection that can occur following FURS. This data, however, will need to be validated and reproduced in larger multi-centre studies.

Urolithiasis in Germany: Trends from the National DRG Database

INTRODUCTION

Urolithiasis is a common disease leading to a high socioeconomic burden due to treatment costs and sickness leave. The aim of this study was to evaluate recent trends in the incidence of urolithiasis in Germany and in the use of therapeutic interventions.

METHODS

Treatment data for all in-patient hospital episodes for urolithiasis between 2005 and 2016 were extracted from the national DRG statistics at DESTATIS and analysed with regard to the corresponding procedures according to the OPS code.

RESULTS

Incidence for urolithiasis was stable at around 120,000 cases per year during the observation period with a male:female ratio of 2:1. Rising numbers were noted for patients >80 years. Nevertheless, the number of coded procedures rose significantly with a marked disproportionate transition from extracorporeal shock wave lithotripsy towards ureterorenoscopy. Percutaneous nephrolithotomy was performed more frequently on a smaller scale.

DISCUSSION/CONCLUSION

While the global incidence of urolithiasis is still rising, Germany, as other Western countries, has reached a plateau. There is a remarkable trend towards invasive treatment of even asymptomatic kidney stones. Besides the effects on individual patients with increased risk for complications, this results in a higher monetary burden to the health care system and society.

Comparison of a single-use, digital flexible ureteroscope with a reusable, fiberoptic ureteroscope for management of patients with urolithiasis

OBJECTIVES

Ureteroscopy is one of the commonest procedures performed to manage urolithiasis. Flexible ureteroscopy has been traditionally based on reusable, fiber-optic ureteroscopes. Technology advancements permitted the development of single-use scopes with digital image. The aim of this study is to compare efficacy and safety between a reusable, fiberoptic ureteroscope with a single-use, digital scope.

PATIENTS AND METHODS

We collected data based on chart review from a prospectively collected database on a tertiary, high-volume hospital in Greece. Baseline, perioperative and postoperative data were gathered and analyzed. Chi-square and Fisher's exact test was used to compare qualitative data and unpaired t-test for continuous data, with a statistical significance set at a = 0.05.

RESULTS

40 patients underwent flexible ureteroscopy with a single- use digital scope, while 37 with the reusable scope. The two groups were matched regarding baseline characteristics and stone-related parameters. After data analysis, a shorter operative time in favor of single-use flexible ureteroscope was detected (45 vs 65 min, p = 0.001), while safety was also in favor of this type of scope with a significantly higher immediate stonefree rate (70% vs 43%, p = 0.005). Overall complications did not differ between the two groups, although a lower sepsis rate was detected in patients treated with single-use scope.

CONCLUSIONS

Our findings indicate that single-use, digital ureteroscopes are a viable alternative for flexible ureteroscopy and management of urolithiasis, especially in centers with deficient facilities for sterilization and ensured funds for more expensive reusable scopes.

Is extracorporeal shockwave lithotripsy (SWL) still suitable for >1.5 cm intrarenal stones? Data analysis of 1902 SWLs

PURPOSE

According to the American Urological Association and European Association of Urology guidelines, shockwave lithotripsy (SWL) is the least-invasive treatment option for kidney stones smaller than 2 cm. However, it is well known that SWL stone-free rates (SFR) decline as stone size increases. We sought to evaluate whether the size limit of 1.5 cm could be a better predictor of success after a single SWL session than current recommendations.

METHODS

Data from an SWL-dedicated center were prospectively scrutinized according to stone locations and sizes. Information on patients' demography, lithotripsy parameters, and outcomes was evaluated by multivariate analysis among 1902 SWLs.

RESULTS

The overall SFR was 70.8% (1347/1902). SFRs according to stone size were <1 cm: 73.8% (825/1118), 1-1.5 cm: 70.4% (401/569) and >1.5 cm: 56.2% (121/215); and according to calculi location were lower pole (LP) 64.4% (398/618), mid pole 73.8% (339/459), upper pole 73.8% (273/370) and renal pelvis 74.1% (337/455). Multivariate analysis revealed better SFR independent better SFR in <1.5 cm (p < 0.01), and non-LP stones (p < 0.01).

CONCLUSION

SWL is an effective treatment modality for kidney stones. The single session reached up to 74.8% SFRs (range 70.8%-74.8%) when indicated for intrarenal non LP stones smaller than 1.5 cm. Patients with stones >1.5 cm or >1 cm located in the LP should be counseled on the lower SFRs after a single SWL session.

Urolithiasis prevalence in the Russian Federation: analysis of trends over a 15-year period

PURPOSE

To conduct a comparative analysis of the prevalence of urolithiasis in the Russian Federation.

METHODS

We analysed urolithiasis prevalence and incidence data from 2005 to 2019 (15 years) for the entire population of Russia. Data were provided by the 'Ministry of Health' of the Russian Federation. The prevalence and incidence of urolithiasis were collected and analysed for both adults and children for each region of the Russian Federation over this 15-year period. Statistical analysis was performed using the SPSS Statistics 21 software package (SPSS). Intergroup correlations and differences between samples in the studied parameters were considered significant at p < 0.05.

RESULTS

A total of 656,911 and 889,891 urolithiasis cases were observed in 2005 and 2019, respectively, an increase in urolithiasis prevalence of 35.4% for the study period, with the growth rate that was fairly uniform. The incidence of urolithiasis in the Russian Federation was 176,773 in 2005, while 205,414 new urolithiasis cases were recorded in 2019, with a clear tendency to a rising incidence of urolithiasis, an increase of 16.2% during the study period. The incidence per 100,000 in children remained stable during the entire period of analysis.

CONCLUSION

The incidence and prevalence of urolithiasis in the adult population steadily increased in all regions of the Russian Federation, while the incidence in children remained stable. The incidence of urolithiasis was associated with an increase in the incidence of diabetes mellitus, obesity and meat consumptions, highlighting the strong association of kidney stone disease with these risk factors.

The role of phagocytic leukocytes following flexible ureterenoscopy, for the treatment of kidney stones: an observational, clinical pilots-study

BACKGROUND

The number of patients undergoing flexible ureterenoscopy (FURS) for the treatment of kidney stones (renal calculi) is increasing annually, and as such the development of post-operative complications, such as acute kidney injury (AKI), haematuria and infection is likely to increase. Phagocytic leukocytes are white blood cells that help fight foreign material such as bacteria and viruses, and they are intrinsically involved in the inflammatory reaction. Investigating the role of phagocytic leukocytes following FURS has not been widely researched. The main aim of the study was to evaluate the role phagocytic leukocytes (neutrophils and monocytes) function, in patients undergoing FURS for the treatment of kidney stones (renal calculi).

METHODS

Fourteen consecutive patients aged between 27 and 70 years (median 49.5 years) undergoing FURS for the treatment of kidney stones were recruited (seven males, seven females). Blood samples were collected from each patient at four time points: baseline (pre-operatively) followed by 30, 120 and 240 min post-operatively. Mononuclear (MN) and polymorphonuclear (PMN) leukocyte sub-populations were isolated by density gradient centrifugation techniques. Neutrophil and monocyte cell function was investigated by measuring the cell surface expression of CD62L (L-selectin), CD11b (Mac-1), CD99 and the intracellular production of hydrogen peroxide (H2O2), via flow cytometry.

RESULTS

Significant increases was observed in monocyte CD62L expression post FURS for the treatment of kidney stones (p ≤ 0.05); while significant decreases were observed in neutrophil CD62L. The levels of the other activation markers CD11b, CD99 and H2O2 corresponded to the increases and decreases seen in CD62L for monocytes and neutrophils respectively, though the changes were not statistically significant (p > 0.05). Limiting factors for this study were the relatively small sample size, and restriction on the recruitment time points.

CONCLUSIONS

This study demonstrates that following FURS for the treatment of kidney stones, monocytes are rapidly activated and produce potent reactive oxygen intermediates. Interestingly, the pattern of expression in neutrophils suggests that these cells are deactivated in response to the treatment. The leukocyte biomarkers assessed during this investigation may have a role in monitoring the 'normal' post-operative response, as no complications occurred in any of the patients; or may help predict potential infectious complications (e.g. urosepsis) that can occur during the post-operative period. This data, however, will need to be validated and reproduced in larger multi-centre studies.

Current scenario of endourological treatment of kidney stones in brazil: results of a national survey

Objective:

To elucidate the current scenario of endourology in Brazil for the treatment of urinary lithiasis, with an emphasis on regional differences and the reasons why certain techniques are still underutilized.

Materials and Methods:

An electronic questionnaire was sent by email to the 4,745 members of the Brazilian Urological Society (BSU) in 2016 to collect information on the 3 main endourological procedures used in the treatment of nephrolithiasis: Semi-rigid ureteroscopy (URS), Flexible ureteroscopy (F-URS) and percutaneous nephrolithotripsy (PCNL).

Results:

A total of 1,267 urologists answered the questionnaire. It was observed that the vast majority perform URS (95.6%), while 80.2% perform F-URS and only 72.1% perform PCNL. Regarding the surgical volume, most perform up to 10 procedures per month (73.4% to 88.2%) and the main impediment was the lack of patients with the pathology (42.1% to 67.7%). The lack of equipment or hospital infrastructure was one of the main limiting factors for rigid (23%) and flexible (38.1%) URS, mainly in the North and Northeast regions of the country. Regarding PCNL, most of them reported lack of practical experience in the method (29.9%). Finally, most urologists expressed interest in taking courses in endourology.

Conclusion:

Ureteroscopy, rigid or flexible, is already well established in the country, requiring the direction of more resources for its practice, especially in less developed regions. Regarding PCNL a significant part of Brazilian urologists still lack practical experience in this procedure, emphasizing the need for greater investment in teaching this technique.

Trends of upper urinary tract stone management in a high volume stone center in Saudi Arabia, 12 years analysis

Introduction:

Urolithiasis is a common urological problem globally with tremendous health and economic burden. In Saudi Arabia, an estimation has shown that the risk of developing a stone episode is 50% higher than that in Western countries. About 20% of males would experience at least one episode by 70 years of age. The introduction of minimally invasive and noninvasive methods such as shockwave lithotripsy (SWL), ureteroscopy (URS), and percutaneous nephrolithotripsy (PCNL) has driven the urologists to more complex decision-making with a noted variance in management options.

Objectives and Methods:

The objective of the study was to observe the trend of upper urinary tract stone management in our institution in the past 12 years.

Methods:

Charts of patients who underwent upper urinary tract lithotripsy procedures of any kind were reviewed. The information obtained included, patient's age, surgeon, surgery type, stone size, stone location, and duration of surgery.

Analysis:

The data obtained were from 2006 to 2016. Excel sheets used for the collection of data and SPSS software was used for analysis.

Results:

The results showed that the majority of the patients were males accounting for 65%. ESWL was the predominant approach from 2006 to 2010. In 2006, ESWL accounted for 77.7% of the cases, 76% in 2007, 70% in 2008, 64% in 2009, and 62% in 2010. However, in 2011, the rates dropped to almost 18% and URS rates have increased from a few cases per year to 64%. The frequency of URS continued to rise through the years until 2015 where URS rates reached 75%. During the 12-year period, URS is the most common upper tract procedure conducted when compared to ESWL and PCNL, accounting for 63%, 16%, and 20%, respectively.

Conclusion:

In our institution, the frequency of URS rose over the years being the most abundant procedure done. ESWL rates have decreased over the years.

Comprehensive analysis of in-hospital delirium after major surgical oncology procedures: A population-based study

INTRODUCTION

Very few population-based assessments of delirium have been performed to date. These have not assessed the implications of delirium after major surgical oncology procedures (MSOPs). We examined the temporal trends of delirium following 10 MSOPs, as well as patient and hospital delirium risk factors. Finally, we examined the effect of delirium on length of stay, inhospital mortality, and hospital charges.

METHODS

We retrospectively identified patients who underwent prostatectomy, colectomy, cystectomy, mastectomy, gastrectomy, hysterectomy, nephrectomy, oophorectomy, lung resection, or pancreatectomy within the Nationwide Inpatient Sample (2003-2013). We yielded a weighted estimate of 3 431 632 patients. Multivariable logistic regression (MLR) analyses identified the determinants of postoperative delirium, as well as the effect of delirium on length of stay, in-hospital mortality, and hospital charges.

RESULTS

Between 2003 and 2013, annual delirium rate increased from 0.7 to 1.2% (+6.0%; p<0.001). Delirium rates were highest after cystectomy (predicted probability [PP] 3.1%) and pancreatectomy (PP 2.6%), and lowest after prostatectomy (PP 0.15%) and mastectomy (PP 0.13%). Advanced age (odds ratio [OR] 3.80), maleness (OR 1.38), and higher Charlson comorbidity index (OR 1.20), as well as postoperative complications represent risk factors for delirium after MSOPs. Delirium after MSOP was associated with prolonged length of stay (OR 3.00), higher mortality (OR 1.15), and increased in-hospital charges (OR 1.13).

CONCLUSIONS

No contemporary population-based assessments of delirium after MSOP have been reported. According to our findings, delirium after MSOP has a profound impact on patient outcomes that ranges from prolonged length of stay to higher mortality and increased in-hospital charges.

Contemporary Analysis of Calculous Nephrectomy Utilization and Outcomes in the United States

Introduction: Calculous nephrectomy was a mainstay of treatment of complex upper tract stone disease up until the 1970s, but data on its contemporary utilization in the current era of rising rates of stone disease are lacking. We characterized the nationwide utilization and outcomes for calculous nephrectomy in the United States. Patients and Methods: The National/Nationwide Inpatient Sample databases for 2001 to 2014 were queried for adults with a principal diagnosis of upper urinary tract calculi (UUTCs), who underwent nephrectomy as well as other inpatient surgeries for UUTCs. Per-population trend in utilization of calculous nephrectomy was analyzed using negative binomial regression. The proportion of calculous nephrectomy as a fraction of all inpatient surgical procedures for UUTCs was analyzed using the Cochran-Armitage test. Patient demographics, hospital characteristics, perioperative outcomes, and complications were analyzed using appropriate statistical tests. Results: Of almost 1.42 million inpatient UUTC procedures performed over the study period, 9232 (0.65%) were calculous nephrectomies. Per-population utilization rate for calculous nephrectomy decreased significantly over time (incidence rate ratio = 0.82; 95% confidence interval = 0.73-0.91, p < 0.001). The proportion of calculous nephrectomy as a fraction of all inpatient surgical procedures for UUTC also decreased significantly over time (p < 0.0001). Majority of the procedures were performed in females, in urban teaching hospitals, and in the Southern United States. The overall complication rate was 38.3%, most commonly hemorrhage requiring transfusion (15.6%). Older age, female gender, and nonprivate insurance or lack of insurance were significant predictors of increased risk of complications, whereas hospitalization in urban hospitals was a predictor of lower risk. Conclusions: Despite increasing prevalence of stone disease in the United States in the contemporary era, utilization of calculous nephrectomy is low and is declining. Inpatient complication rates are moderately high and influenced by patient sociodemographic and hospital characteristics.

Assessing Cost-Effectiveness of New Technologies in Stone Management

Diagnosis, treatment, and follow-up are all influential in determining the overall cost to the health care system for kidney stones. New innovations in the field of nephrolithiasis have been abundant, including disposable ureteroscopes, ultrasound-guided approaches to percutaneous nephrolithotomy, and advanced laser lithotripters. Identifying cost-effective treatment strategies encourages practitioners to be thoughtful about providing value-based high-quality care and remains on important principle in the treatment of urinary stone disease.

Recent surgical treatments for urinary stone disease in a Korean population: National population-based study

OBJECTIVES

To provide surgical treatment trends for urinary stone disease in Korea.

METHODS

We analyzed medical service claim data of surgical treatments to urinary stone disease submitted by medical service providers from the Health Insurance Review and Assessment Service from 2009 to 2016.

RESULTS

There was a significantly increasing trend among outpatients and inpatients for urinary stone disease from 2009 to 2016 (R²  = 0.643, P = 0.017; R²  = 0.575, P = 0.029). The number of shock wave lithotripsy for treating urinary stone disease increased by 16% from 89 553 in 2009 to 104 013 in 2016 (R²  = 0.684). The number of ureteroscopic lithotripsy increased by 97% from 6106 in 2009 to 12 057 in 2016 (R²  = 0.99). The number of flexible ureteroscopic lithotripsy increased by 16-fold from 219 in 2009 to 3712 in 2016 (R²  = 0.756). The number of percutaneous nephrolithotomy increased by 99.7% from 919 in 2009 to 1835 in 2016 (R²  = 0.987). The use of non-contrast and contrast-enhanced computed tomography in the diagnostic codes for urinary stone disease increased by 394.8% and 263.3% from 2009 to 2016, respectively (R²  = 0.83; R²  = 0.967). Conversely, the use of intravenous pyelography decreased 26.2% over the same period (R²  = 0.945).

CONCLUSIONS

Outpatient and inpatient procedures for urinary stone disease have increased over the past 8 years in Korea. Shock wave lithotripsy is the most widely used treatment modality for urinary stone disease, and endoscopic surgical procedures are rapidly being implemented. There has been a steep increase in the use of computed tomography, whereas conventional intravenous pyelography is declining.

Postoperative paralytic ileus after major oncological procedures in the enhanced recovery after surgery era: A population based analysis

BACKGROUND

Enhanced recovery after surgery (ERAS) protocols have been developed and implemented as of 2001 and may have significantly reduced several complication types including paralytic ileus. However, no formal analyses targeted paralytic ileus rates after contemporary major surgical oncology procedures. We examined temporal trends of paralytic ileus following ten major oncological surgical procedures. The effect of paralytic ileus on length of stay (LOS) and total hospital charges was examined. Univariable and multivariable linear and logistic regression analyses were used.

METHODS

Between 2003 and 2013, we retrospectively identified patients, who underwent prostatectomy, colectomy, cystectomy, mastectomy, gastrectomy, hysterectomy, nephrectomy, oophorectomy, lung resection or pancreatectomy within the Nationwide Inpatient Sample. A total of 3 431 602 patients were included in our analyses. Annual paralytic ileus rate differences after major oncological surgical procedures were evaluated using linear regression. Multivariable logistic regression analyses were used to test for paralytic ileus rates determinants, as well as on the effect of paralytic ileus rates on LOS and hospital charges.

RESULTS

Paralytic ileus rates ranged from 0.1% (mastectomy) to 23.2% (cystectomy) after ten examined major oncological surgical procedures. Overall annual paralytic ileus rates did not change [estimated annual percentage change (EAPC)+0.1%, p = 0.7]. Multivariable logistic regression derived predicted probabilities (PP) of paralytic ileus were highest for cystectomy (PP: 26.1%) and colectomy (PP: 17.15%) and were lowest for lung resection (PP: 2.22%) and mastectomy (PP: 0.16%). In analyses predicting LOS above the 75th percentile, paralytic ileus effect after mastectomy (OR: 14.66) and prostatectomy (OR: 13.21) ranked, as highest and second highest respectively. In analyses predicting hospital charges above the 75th percentile, paralytic ileus effect after mastectomy (OR: 2.21) and oophorectomy (OR: 1.99) ranked as highest and second highest respectively.

CONCLUSIONS

Despite implementation of ERAS protocols paralytic ileus rates have not decreased over time. Gastrointestinal procedures are among the highest contributors of paralytic ileus. Moreover, procedures with short LOS represent the strongest relative contributors to LOS increases and increases in hospitalization costs.

Comparison of Scoring Systems in Predicting Success of Percutaneous Nephrolithotomy

Background:

Scoring systems are useful to inform the patients about the success and complication rates of the operation prior the surgery.

Aims:

To determine the applicability of the popular scoring systems (Guy’s, stone size, tract length, obstruction, number of involved calices, and essence/stone density and Clinical Research Office of the Endourological Society) by means of examining preoperative data of patients treated with percutaneous nephrolithotomy.

Study Design:

Cross sectional study.

Methods:

We retrospectively reviewed files of the patients who had undergone percutaneous nephrolithotomy in our center between 2011 and 2015. Excluded from the study were patients aged <18 years, and those who were not assessed preoperatively with computed tomography. Preoperative computed tomography images of all patients were assessed by a single observer, and patients were graded based on three scoring system. Demographic data were analyzed along with perioperative data (operation, fluoroscopy, length of hospital stay, changes in hematocrit values, location, and number of access sites, stone-free and complication rates).

Results:

A total of 298 patients who had been treated with 300 procedures were enrolled into the study. Mean age, stone burden, number of stones, and density were 48.1±12.9 years, 663.5±442.8 mm², 1.8±1.1 and 888.3±273 HU respectively. Scores of the cases based on Guy’s, stone size, tract length, obstruction, number of involved calices, and essence/stone density, and Clinical Research Office of the Endourological Society scoring system were calculated as 2, 7.6, and 222.1 points respectively. 81.6% of the patients were stone-free. Complications were detected in 30 (9.9%) patients. Based on receiver operating characteristic curve analysis a positive correlation was detected between success rate and scoring systems, i.e., Guy’s (p=<0.001, r=-0.309), stone size, tract length, obstruction, number of involved calices, and essence/stone density (p=<0.001, r=-0.295), and Clinical Research Office of the Endourological Society (p=<0.001, r=0.426). The Clinical Research Office of the Endourological Society scoring system had the highest predictive value. The sensitivity rates rates for Guy’s, Clinical Research Office of the Endourological Society and Stone scoring system were as 78.78%, 80% and 82.34% respectively.

Conclusion:

All of scoring systems predicted correctly the success of the percutaneous nephrolithotomy procedures. The Clinical Research Office of the Endourological Society scoring system had the highest predictive value.

A clinical evaluation of the new digital single-use flexible ureteroscope (UscopePU3022): an international prospective multicentered study

Introduction

We assessed the clinical performance of a new digital single-use flexible ureteroscope (UscopePU3022).

Material and methods

A prospective cohort study was carried out across 11 centers (July-Oct. 2017). The UscopePU3022 was assessed regarding ease of insertion; deflection, image quality, maneuverability and overall performance using either a visual analog* or Likert scale.

Results

A total of 56 procedures were performed in 11 centers (16 surgeons) with the indication being renal stones in 83%. The median score for ease of scope insertion was 10 (3-10). Intraoperative maneuverability was rated as 'good' in 38% and 'very good' in 52%. Visual quality was rated as 'poor or bad' in 18%, 'fair' in 37% and 'good or very good' in 43%. Two scopes failed intraoperatively (4%). Preoperative and postoperative median upward and downward deflection was 270 degrees. Compared to standard flexible ureteroscopy (f-URS) maneuverability was rated as 'equivalent' in 30% and 'better' in 60%; visual quality was 'worse' in 38% and 'equivalent or better' in 62%; limb fatigue scores were 'better' in 86%; and overall performance was 'worse' in 55% and 'equivalent or better' in 45%.

Conclusions

UscopeTM3022 performed well with regards to maneuverability, deflection and limb fatigue and appears to be at least non-inferior to standard f-URS with regards to these parameters. Poor image quality is a concern for UscopePU3022 with it receiving a low overall performance rating when compared to standard f-URS. Despite this it scored highly when investigators were asked if they would use it in their practice if it was cost-effective to do so.

Italian endourological panorama: results from a national survey

Introduction

The purpose of this survey was to explore the dissemination of flexible ureteroscopy (fURS), shockwave lithotripsy (SWL) and percutaneous nephrolithotomy (PCNL) in the Italian urological community and to know the real availability of the complex endourological armamentarium all over the country.

Materials and methods

An online questionnaire characterizing the case volume/year of upper urinary tract stone treatment and the availability of flexible ureteroscopes (FUs) armamentarium was sent to all urological Italian centers.

Results

The survey was sent to 294 urological centers and 146 responded (49.7%). The case volume/year of fURS was the following: <20 cases in 20 centers (13.7%); 20-50 cases in 40 centers (27.4%), >50- <100 cases in 55 centers (37.8%) and >100 cases in 28 centers (19.2%). The case volume/year of SWL was the following: <50 cases in 18 centers (12.3%); >50- <200 cases in 56 centers (36.4%) and >200 cases in 35 centers (24%). In 37 centers (25.3%) SWL was not utilized at all. The case volume/year of PCNL was the following: <10 cases in 20 centers (14%); >10 - <30 cases in 55 centers (30%), >30- < 50 cases in 33 centers(23%), >50- <100 cases in 13 centers (9%) and >100 procedures in 2 centers (1%). However, 24 centers (16%) did not perform any PCNL procedure.Four centers (3%) did not have any FU at the moment of the survey. The availability of FUs was as follows: 1 FU in 21 (14%) centers, 2 FUs in 61 (42%) centers, 3 FUs in 29 (20%) centers, 4 FUs in 13 (9%) centers and ≥5 FUs in 16 (9%) centers. Only 82 (56%) centers had all of their FUs in working condition.

Conclusions

This survey succeeded in providing a complete overview on the Italian endourological panorama.

Steep Infundibulopelvic Angle as a New Risk Factor for Flexible Ureteroscope Damage and Complicated Postoperative Course

OBJECTIVE

The increasing number of flexible ureterorenoscopy (fURS) procedures, the fragility of devices, and their growing repair costs represent a substantial burden for urological departments worldwide. No risk factors of flexible ureteroscope damage have been identified so far. The objective of this study was to investigate the impact of infundibulopelvic angle (IPA) on device damage and on other intraoperative and postoperative factors such as length of hospital stay, surgical complications, stone-free rate (SFR), operation, and fluoroscopy time.

MATERIALS AND METHODS

In a retrospective monocentric study, IPA was measured based on intraoperative retrograde pyelography images taken during fURS. All procedures were conducted with modern reusable flexible ureteroscopes: Karl Storz Flex-X2 or Olympus URF-V. Statistical analysis was performed in RStudio (version 1.0.136) with the unpaired t-test and Mann-Whitney U test. Pearson correlation coefficient (Pearson's r) was measured whenever applicable.

RESULTS

In total, 381 fURS performed between September 2013 and March 2017 were analyzed: 260 (68.24%) for kidney stone operation and 121 (31.76%) for diagnostic purposes; of these, 38 (9.97%) devices were postoperatively deemed defective. IPA values were significantly steeper in cases with flexible ureteroscope damage compared to cases without damage (median 42.5 degrees vs 56.0, p < 0.001). Steeper IPA was significantly associated with the occurrence of Clavien-Dindo ≥2 complications (median 51.0 degrees vs 55.0, p = 0.005) as well as prolonged hospital stay (median 51.0 degrees vs 55.0, p = 0.014). No influence on SFR was observed (p > 0.05). IPA did not correlate with operation or fluoroscopy time.

CONCLUSIONS

Steep IPA can be considered the first risk factor predicting both flexible ureteroscope damage and an unfavorable postoperative course. A better understanding of damage mechanisms is the key for the proper indications to use costly single-use devices.

Metabolic evaluation guidelines in patients with nephrolithiasis: Are they being followed? Results of a national, multi-institutional, quality-assessment study

INTRODUCTION

The significant cost burden of kidney stones underscores the importance of best clinical practice in kidney stone management. We evaluated adherence to kidney stone metabolic evaluation guidelines in a Canadian population and the interest of patients with regard to prevention.

METHODS

A questionnaire based on Canadian Urological Association (CUA) best practice guidelines was designed. Patients presenting for extracorporeal shockwave lithotripsy treatment (ESWL) were administered this questionnaire to evaluate risk factors of stone disease and assess the use of metabolic evaluations. Patients were asked if they received explanations about their results and if they were interested in kidney stone prevention.

RESULTS

We identified 530 patients at five academic institutions; 79.4% had at least one indication to receive a metabolic evaluation (high-risk stone formers), which increased to 96.6% if first-time stone formers whom reported an interest in metabolic evaluation were included. However, only 41.1 % of these patients had a metabolic evaluation. Endourologists ordered metabolic evaluation more often than other referring urologists (63.6% vs. 36.5%; p<0.001). Furthermore, urologists ordered metabolic evaluations more often than other prescribing physicians (68.9% vs. 31.1%; p<0.001). Sixty-two percent of patients received explanations about their metabolic evaluation results and 77.5% understood them. Regarding prevention, 84.1% and 83.8% were interested in more explanations and in following a diet or taking a medication, respectively.

CONCLUSIONS

Adherence to CUA metabolic evaluation guidelines is suboptimal and could be improved by urologists referring patients for ESWL. Communication between physician and patient may not be adequate. The majority of stone formers are interested in kidney stone prevention.

Worldwide Trends of Urinary Stone Disease Treatment Over the Last Two Decades: A Systematic Review

INTRODUCTION

Numerous studies have reported on regional or national trends of stone disease treatment. However, no article has yet examined the global trends of intervention for stone disease.

METHODS AND MATERIALS

A systematic review of articles from 1996 to September 2016 for all English language articles reporting on trends of surgical treatment of stone disease was performed. Authors were contacted in the case of data not being clear. If the authors did not reply, data were estimated from graphs or tables. Results were analyzed using SPSS version 21, and trends were analyzed using linear regression.

RESULTS

Our systematic review yielded 120 articles, of which 8 were included in the initial review. This reflected outcomes from six countries with available data: United Kingdom, United States, New Zealand, Australia, Canada, and Brazil. Overall ureteroscopy (URS) had a 251.8% increase in total number of treatments performed with the share of total treatments increasing by 17%. While the share of total treatments for percutaneous nephrolithotomy (PCNL) remained static, the share for extracorporeal shockwave lithotripsy and open surgery fell by 14.5% and 12%, respectively. There was significant linear regression between rising trends of total treatments year on year for URS (p < 0.001).

CONCLUSION

In the last two decades, the share of total treatment for urolithiasis across the published literature has increased for URS, stable for PCNL, and decreased for lithotripsy and open surgery.

In Vitro Evaluation of Single-Use Digital Flexible Ureteroscopes: A Practical Comparison for a Patient-Centered Approach

OBJECTIVE

To compare the manufacturing and in vitro performance characteristics of two single-use flexible ureteroscopes with a permanent optical flexible ureteroscope.

MATERIALS AND METHODS

Two single-use flexible ureteroscopes, LithoVue (Boston Scientific) and Pusen (1rs. generation; Zhuhai Pusen Medical Technology Company Limited, China), were tested and compared with a permanent Flex-X² ureteroscope (Karl Storz, Germany) in terms of technical characteristics, optics, deflection mechanism, and additional parameters which could potentially affect surgical technique.

RESULTS

Pusen was the lightest ureteroscope while the LithoVue had the longest working length. LithoVue had a higher resolution power than the other two ureteroscopes at all distances tested (p < 0.001). Pusen showed higher resolution than Flex-X² (p < 0.01). Field of view was wider for LithoVue (87°), followed by Flex-X² (85°) and Pusen (75°). Color representation was superior for Flex-X² than LithoVue and then Pusen. LithoVue outperformed Pusen and Flex-X² for all settings with instruments in terms of deflection loss (p < 0.01). Pusen had the highest irrigation flow (52 mL/min) with an empty working channel (p < 0.01). LithoVue and Pusen showed similar flow rates with a 200 μm (21 mL/min) and 365 μm laser fiber (7 mL/min) and 1.3F basket (18 mL/min), being superior to Flex-X² (p < 0.01). With the 1.9F basket, LithoVue had superior flow rate (7 mL/min) than Pusen (3.5 mL/min) and Flex-X² (4 mL/min; p = 0.01).

CONCLUSION

LithoVue outperformed the other ureteroscopes in terms of optical resolution, field of view, deflection capacity, and irrigation flow with larger instruments. Pusen is the lighter scope and showed better results in terms of irrigation when no instruments are in place. Flex-X² was superior in terms of color representation.

Retrospective Cost Analysis of a Single-Center Reusable Flexible Ureterorenoscopy Program: A Comparative Cost Simulation of Disposable fURS as an Alternative

OBJECTIVE

The increasing number of flexible ureterorenoscopy (fURS) procedures, the fragility of devices, and their growing maintenance and repair costs represent a substantial burden for urologic departments. Disposable single-use fURS devices offer many advantages over reusable fURS. Among them, the LithoVue™ model shows the best clinical utility. In our study, we assessed the economic aspects of reusable fURS application compared with the potential costs and benefits of single-use fURS (LithoVue™). Indications for single-use fURS were proposed based on potential risk factors of reusable fURS damage.

MATERIALS AND METHODS

This single-center retrospective analysis compared the actual cost of reusable fURS procedures with the potential costs of LithoVue™ based on the price offered by the manufacturer. Consecutive case analysis of damaged fURS was performed to determine potential risk factors associated with fURS damage.

RESULTS

The study group consisted of 423 reusable fURS procedures conducted between January 2013 and December 2016. During this period, 102 (24.11%) diagnostic fURS and 321 (75.89%) fURS for kidney stone therapy were performed. In 32 of 423 (7.57%) fURS cases, devices were postoperatively deemed defective, 9 of which were used for diagnostic procedures (9/102; 8.82%), 7 for stone removal (7/148; 4.73%), and 16 for stone removal and laser (Ho:YAG) application (16/173; 9.25%). The average cost per reusable fURS procedure was found to be €503.26.

CONCLUSIONS

Disposable fURS is a more expensive option for high-volume centers. Based on our case analysis, laser disintegration treatment of multiple, large stones in the lower kidney pole of recurrent stone formers, as well as a steep infundibulopelvic angle (IPA ≤50°), seems to be the main risk factor for fURS damage. For these cases, disposable fURS may be a cost-effective alternative; however, a prospective comparison of economic outcomes between disposable and reusable fURS, together with confirmation of the proposed damage risk factors, is needed.

Mini PCNL for renal calculi: does size matter?

OBJECTIVE

To evaluate the minimally invasive percutaneous nephrolithotomy (MIP) system for renal calculi.

PATIENTS AND METHODS

Consecutive patients undergoing mini-percutaneous nephrolithotomy (mPCNL) procedures with the MIP system were enrolled. Patient position, American Society of Anesthesiologists classification, puncture location, stone clearance, postoperative drainage and complications were recorded, and features unique to MIP were noted.

RESULTS

In all, 30 patients underwent 32 mPCNL procedures. The mean stone size was 17 (10.75-21.25) mm and the mean number of stones was 1 (1-2). The median stone clearance rate was 96.5 (95-100)%. The complication rate was 9.3%. No patient required a transfusion. In addition to these outcomes, we noted that the MIP system has many advantages over conventional PCNL (cPCNL). It is easy to learn and can be performed in both supine and prone positions. It is safe for supracostal puncture, provides excellent access to nearly all calyces and upper ureter, has multiple stone treatment options, can be used as an adjunct to cPCNL, and can be performed as a tubeless procedure.

CONCLUSION

Our experience with the MIP system has shown several advantages over cPCNL. mPCNL with the MIP system has several features that suggest it should be considered as an alternative or adjunct to cPCNL, ureteroscopy and extracorporeal shockwave lithotripsy.

Burden of Urolithiasis: Trends in Prevalence, Treatments, and Costs

CONTEXT

The recent evolution of management options for urolithiasis has presented a unique dilemma for the modern urologist. A comprehensive understanding of epidemiological trends along with current provider preferences in treating urinary stones would be beneficial.

OBJECTIVE

To review trends in the prevalence, treatments, and costs of urolithiasis worldwide.

EVIDENCE ACQUISITION

A literature review was performed using the MEDLINE database, the Cochrane Library Central search facility, Web of Science, and Google Scholar between 1986 and 2016. Keywords used for the search were "urolithiasis" and "prevalence; treatment; and cost".

EVIDENCE SYNTHESIS

The incidence and prevalence of urinary stones are rising around the world, including regions that have historically had low rates of urolithiasis. Common theories explaining this trend involve climate warming, dietary changes, and obesity. Shockwave lithotripsy (SWL) has been the preferred mode of treatment since its introduction in the 1980s. However, ureteroscopy (URS) has become increasingly popular for small stones regardless of location because of lower recurrence rates and costs. Developing countries have been slower to adopt URS technology and continue to use percutaneous nephrolithotomy at a steady rate.

CONCLUSIONS

URS has recently challenged SWL as the treatment modality preferred for small upper urinary tract stones. In some cases it is less expensive but still highly effective. As the burden of stone disease increases worldwide, appropriate selection of stone removal therapies will continue to play an important role and will thus require further investigation.

PATIENT SUMMARY

Urinary stones are becoming more prevalent. Recent advances in technology have improved the management of this disease and have decreased costs.

[Evaluation of the operating results and costs associated with the implementation of a flexible ureteroscopy activity within a university hospital center]

INTRODUCTION

The increasing use of flexible ureteroscopy (USSR) sets the cost problems inevitably associated with the fragility of these endoscopes. The aim of this work is to clear from a recent example (universitary hospital) results, costs during the implementation of this technique.

MATERIAL AND METHODS

This is a retrospective study conducted from December 2012 (date of introduction of the activity) in March 2015 concerning the USSR made in a French universitary hospital for stone disease. In this analysis, the cost of consumables was not evaluated, nor the costs of the operating theater or hospitalization.

RESULTS

One hundred forty-one hundred and thirteen patients USSR were conducted by seven surgeons. Seventeen breakages and failures have been identified and have led to the sending of the endoscope for repair. Breakage rate and failure was 12%. All failures were treated with a standard exchange of the device (including 4 standard exchanges made under warranty). The estimated average cost of outages was 3600 euros. This represents an average cost per procedure of about 625 euros (acquisition plus cost of failures) without counting the costs of sterilization or high-level disinfection. The impossibility of relocating the lower calyx stones is associated with an excess risk of breakage (odd ratio: 2.92 CI95: [1.02; 8.37]).

CONCLUSION

This study is novel because it focuses on the cost of implementing a technique in a French university hospital. The use of flexible ureteroscope to unique uses might be an interesting source of savings in the implementation of this technique. This remains to be evaluated.

LEVEL OF EVIDENCE

5.

The Risk of Chronic Kidney Disease Associated with Urolithiasis and its Urological Treatments: A Review

PURPOSE

Urolithiasis can impair kidney function. This literature review focuses on the risk of kidney impairment in stone formers, the specific conditions associated with this risk and the impact of urological surgery.

MATERIALS AND METHODS

The PubMed® and Embase® databases were searched for publications on urolithiasis, its treatment, and the risk of chronic kidney disease, end stage renal disease and nephrectomy in stone formers.

RESULTS

In general, renal stone formers have twice the risk of chronic kidney disease or end stage renal disease, and for female and overweight stone formers the risk is even higher. Patients with frequent urinary tract infections, struvite stones, urinary malformations and diversions, malabsorptive bowel conditions and some monogenic disorders are at high risk for chronic kidney disease/end stage renal disease. Shock wave lithotripsy or minimally invasive urological interventions for stones do not adversely affect renal function. Declines in renal function generally occur in patients with preexisting chronic kidney disease or a large stone burden requiring repeated and/or complex surgery.

CONCLUSIONS

Although the effect size is modest, urolithiasis may cause chronic kidney disease and, thus, it is mandatory to assess patients with renal stones for the risk of chronic kidney disease/end stage renal disease. We suggest that all guidelines dealing with renal stone disease should include assessment of this risk.

Recent advances in understanding and managing urolithiasis

During the last few years, there has been relevant progress in both understanding and managing urolithiasis. Our knowledge of stone formation has changed; although the importance of urine biochemistry was questioned by several investigators years ago, the decisive role of cellular processes (induced by oxidative stress) and the renal papilla has only recently been generally accepted as the most important step in stone formation. For calcium oxalate urolithiasis, the formation of papillary calcifications plays a key role and is of prognostic relevance. Further research has to concentrate on these aspects of preventing urolithiasis. Stone prevention (metaphylaxis) is a major issue when considering the burden it places on healthcare systems. An effective metaphylaxis could lower the cost of stone therapy significantly. For uric acid urolithiasis, so far there is only preliminary information available showing that papillary plaques are not as important as they are in calcium oxalate urolithiasis. Concerning stone management, endourology has improved stone therapy significantly during the last few years. Morbidity decreased and success (stone-free) rates increased. Therefore, the indications for extracorporeal shockwave lithotripsy (ESWL) narrowed. ESWL, however, still has its place in stone therapy. There is not one single treatment modality that is equally effective for all situations. It is important to observe the differential indications for different stones depending on size, localization, and composition.

A large 15 - year database analysis on the influence of age, gender, race, obesity and income on hospitalization rates due to stone disease

Purpose:

To assess the public hospitalization rate due to stone disease in a large developing nation for a 15-year period and its association with socio-demographic data.

Materials and Methods:

A retrospective database analysis of hospitalization rates in the Brazilian public health system was performed, searching for records with a diagnosis code of renal/ureteral calculi at admission between 1998–2012. Patients managed in an outpatient basis or private care were excluded. Socio-demographic data was attained and a temporal trend analysis was performed.

Results:

The number of stone-related hospitalizations increased from 15.7%, although the population-adjusted hospitalization rate remained constant in 0.04%. Male:female proportion among hospitalized patients was stable (49.3%:50.7% in 1998; 49.2%:50.8% in 2012), though there was a significant reduction in the prevalence of male hospitalizations (−3.8%;p=0.041). In 2012, 38% of hospitalized patients due to stone disease had 40–59 years-old. The ≥80 years-old strata showed the most significant decrease (−43.44%;p=0.022), followed by the 20–39 (−23.17%;p<0.001) and 0–19 years-old cohorts (−16.73%;p=0.012). Overall, the lowest relative hospitalization rates were found for yellow and indigenous individuals. The number of overweight/obese individuals increased significantly (+20.6%), accompanied by a +43.6% augment in the per capita income. A significant correlation was found only between income and obesity (R=0.64;p=0.017).

Conclusions:

The prevalence of stone disease requiring hospitalization in Brazil remains stable, with a balanced proportion between males and females. There is trend for decreased hospitalization rates of male, <40 and ≥80 years-old individuals. Obesity and income have a more pronounced correlation with each other than with stone disease.

Hospital-Based Analysis of Trends and Outcomes for Patients Undergoing Pyelolithotomy

OBJECTIVE

To determine trends in pyelolithotomy, evaluate risk factors for complications, and evaluate the difference in outcomes and charges between open and minimally invasive (MI) techniques.

PATIENTS AND METHODS

We used the Nationwide Inpatient Sample to identify patients with a diagnosis of having nephrolithiasis undergoing pyelolithotomy from 2008 to 2012. Total charges were inflation-adjusted to U.S. dollars in 2012. Patient demographics, hospital characteristics, and outcomes were reported and compared between open and MI groups after survey weighting.

RESULTS

We included a survey-weighted population of 17,294 patients, of whom 841 (4.9%) had MI pyelolithotomy. The proportion of MI cases increased by 2.57% annually (r² = 0.921, p = 0.01), although total pyelolithotomy cases remained stable. Simultaneous pyeloplasty occurred in 6.6% of all patients. Patients receiving open surgery experienced longer length of stay (3.9 days vs 2.7 days; p < 0.001), but accrued equivalent inflation-adjusted charges ($49,588 ± 2088 vs $51,716 ± 4893; p = 0.665). On multivariable analysis, higher Elixhauser comorbidity index and presence of any genitourinary anomaly were associated with experiencing a complication, while undergoing surgery at a top quartile hospital and elective admission status were protective against complications. MI technique and simultaneous ureteropelvic junction repair did not alter complication risk.

CONCLUSION

While the annual number of pyelolithotomy cases was stable, there was an increasing trend toward MI technique. Both patient and hospital factors can significantly alter the risk for complications following pyelolithotomy.

Trends in urological stone disease: a 5-year update of hospital episode statistics

OBJECTIVE

To provide a 5-year follow-on update on the changes in prevalence and treatment of upper urinary tract (UUT) stone disease in England.

METHODS

Data from the Hospital Episode Statistics (HES) website (http://www.hesonline.nhs.uk) were extracted, summarised, analysed, and presented.

RESULTS

The total number of UUT stone hospital episodes increased slightly from 83 050 in 2009-2010 to 86 742 in 2014-2015 (4.4% increase). The use of shockwave lithotripsy (SWL) for treating all UUT stones remained stable over the 5-year study period following a significant increase in previous years. There was a 49.6% increase in the number of ureteroscopic stone treatments from 12 062 in 2009-2010 to 18 055 in 2014-2015. Increase in ureterorenoscopy (flexible ureteroscopy) showed the most rapid increase from 3 267 to 6 631 cases in the 5-year study period (103% increase). The gap between the total number of ureteroscopies and SWL treatments continues to narrow. Open stone surgery continued to decline with only 30 reported cases in 2014-2015. Due to the continued rapid increase in the number of ureteroscopies performed, treatment for stone disease has continued to increase significantly in comparison to other urological activity.

CONCLUSION

This study provides an update on the changing landscape of the management of UUT stones in England. It shows a sustained high prevalence of stone disease commensurate with levels in other developed countries. This study reveals a trend in the last 5 years to surgically intervene on a higher proportion of patients with stones. As in other countries, there is a significant increase in the use of ureteroscopy (particularly intrarenal flexible ureteroscopy) in England. These data have important implications for work-force planning, training, service delivery, and research in the field of urolithiasis.

Multicenter External Validation and Comparison of Stone Scoring Systems in Predicting Outcomes After Percutaneous Nephrolithotomy

BACKGROUND AND PURPOSE

Several scoring systems have recently emerged to predict stone-free rate (SFR) and complications after percutaneous nephrolithotomy (PCNL). We aimed to compare the most commonly used scoring systems (Guy's stone score, S.T.O.N.E. nephrolithometry, and CROES nomogram), assess their predictive accuracy for SFR and other postoperative variables, and develop a risk group stratification based on these scoring systems.

MATERIALS AND METHODS

We performed a retrospective review of patients who have had a PCNL at four academic institutions between 2006 and 2013. Primary outcome was SFR within 3 weeks of the surgery and secondary outcomes were operative time (OT), complications, and length of stay (LOS). We performed chi-squared, t-test, logistic, linear, and Poisson regressions, as well as receiver operating characteristics curve with area under the curve (AUC) calculation.

RESULTS

We identified 586 patients eligible for analysis. Of these, 67.4% were stone free. Guy's, S.T.O.N.E., and CROES score were predictive of SFR on multivariable logistic regression (odds ratio [OR]: 1.398, 95% confidence interval [CI]: 1.056, 1.852, p = 0.019; OR: 1.417, 85% CI: 1.231, 1.631, p < 0.001; OR: 0.993, 95% CI: 0.988, 0.998, p = 0.004) and have similar predictive accuracy with AUCs of 0.629, 0.671, and 0.646, respectively. On multivariable linear regression, only S.T.O.N.E. was an independent predictor of longer OT (β = 14.556, 95% CI: 12.453, 16.660, p < 0.001). None of the scores were independent predictors of postoperative complications or a longer LOS. Poisson regression allowed for risk group stratification and showed the S.T.O.N.E. score and CROES nomogram to have the most distinct risk groups.

CONCLUSIONS

The three evaluated scoring systems have similar predictive accuracy of SFR. S.T.O.N.E. has additional value in predicting OT. Risk group stratification can be used for patient counseling. Further research is needed to identify whether or not any is superior to the others with regard to clinical usefulness and predictive accuracy.

Comparison of minimally invasive percutaneous nephrolithotomy and flexible ureteroscopy for the treatment of intermediate proximal ureteral and renal stones in the elderly

The aim of this study is to compare the outcomes of flexible ureteroscopy (fURS) and minimally invasive percutaneous nephrolithotomy (mPNL) for the treatment of renal and/or proximal ureteral stones sized 1-2 cm in the elderly (≥60 years). Between January 2010 and March 2015, 184 consecutive mPNL and fURS were performed to treat intermediate renal and/or proximal ureteral stones in geriatric patients. The records were retrospectively reviewed and outcomes were compared. Although no significant difference was found in the complication rate between two groups, a statistical trend (p = 0.059) in favor of fURS was observed. In addition, multivariate analysis demonstrated that mPNL, preoperative positive urine culture and lower hemoglobin were independent risk factors for postoperative complication (p = 0.016, p = 0.021, p = 0.001, respectively). And fURS was significantly associated with less hemoglobin drop, red blood cell transfusion, analgesics requirement, postoperative hospital duration, and charges of laboratory tests, medical examinations and medications (p = 0.019, p = 0.037, p = 0.006, p = 0.000 and p = 0.007, p = 0.000, p = 0.000, p = 0.001, respectively), while higher costs of operations (p = 0.008). Receiver operating characteristic curve suggested a preoperative hemoglobin of 106.5 g/L as the threshold for predicting red blood cell transfusion after mPNL. The overall one-session stone-free rate of fURS at 1 month was lower (p = 0.006), while it was similar for solitary stone between two groups. Comorbidity and previous stone surgery did not affect postoperative complication and stone-free rate. This study shows that mPNL is more effective for multiple stones, but fURS is associated with potentially less complications and postoperative hospital stay. Furthermore, preoperative hemoglobin level and urine culture can be used to predict postoperative complication risk and they may be helpful in choosing treatment methods for the elderly.