Worldwide Impact of Warmer Seasons on the Incidence of Renal Colic and Kidney Stone Disease: Evidence from a Systematic Review of Literature

The role of fluid intake in the prevention of kidney stone disease: A systematic review over the last two decades

OBJECTIVE

The incidence of kidney stone disease (KSD) is rising worldwide; hence, more focus must be directed toward its etiology and risk factors. Increasing fluid intake is recommended as the most ideal prevention; yet, there is inconsistent evidence surrounding optimum volumes and types of fluid that affect stone formation. This review aimed to analyze the published literature on fluid intake and types of fluid consumed and their impact on KSD prevention.

MATERIAL AND METHODS

Papers were acquired from databases: MEDLINE, EMBASE, PubMed, CINAHL, and Cochrane Library. Included English language studies that involved adults consuming beverages along with a standardized diet in relation to KSD. Those failing to control dietary factors were excluded.

RESULTS

After an initial search of 1099 papers, 9 (541 participants) were included in the final review. Six varieties of water and ten different types of juices were investigated. Higher fluid intake was associated with increased urine output and reduced stone formation. Water with high calcium content seemingly increased the rate of calcium oxalate (CaOx) stone formation. The relative supersaturation of CaOx in urine was decreased with grapefruit, apple, orange juices, and sodas, whereas cranberry juice increased it. Plum juice and the energy drink Gatorade had no effect on stone formation.

CONCLUSION

Fluids low in calcium seem to reduce the risk of KSD. Certain varieties of fluid, such as grapefruit, apple, and orange juices reduce urine CaOx saturation, with a subsequent reduction in stone formation. Findings from this review could contribute to primary prevention for those at risk of KSD.

Role of Endourological Procedures (PCNL and URS) on Renal Function: a Systematic Review

PURPOSE OF REVIEW

To present the latest evidence related to the impact of ureteroscopy (URS) and percutaneous nephrolithotomy (PCNL) on the renal function.

RECENT FINDINGS

Our review suggests that the overall renal function is not detrimentally affected by endourological interventions (URS, PCNL). This is however influenced by the preoperative renal function, presence of comorbidities such as diabetes and hypertension. For PCNL procedures, tract multiplicity, preoperative UTI, and postoperative bleeding also contribute to a decline in renal function. This review suggests that endourological interventions do not adversely affect renal function and tend to improve it in patients who do not have a poor renal function prior to the procedure. Several factors including poor preoperative renal function, diabetes, hypertension, and multiple percutaneous tracts appear to predispose patients to declining renal function after procedure, and these patients should be counseled for and followed up appropriately.

The influence of pelvicalyceal system anatomy on minimally invasive treatments of patients with renal calculi

INTRODUCTION AND OBJECTIVES

Nephrolithiasis has a multifactorial etiology, wherein, besides metabolic factors, the anatomy of the pelvicalyceal system might play a role. Using 3D-reconstructions of CT-urography (CT-U), we studied the morphometric properties of pelvicalyceal anatomy affecting kidney stone formation and compared those with existing literature on their effect on minimally invasive treatment techniques for renal calculi.

METHODS

CT-U's were made between 01-01-2017 and 30-09-2018. Patients were chronologically included in two groups: a nephrolithiasis group when ≥ 1 calculus was present on the CT-U and a control group of patients with both the absence of calculi on the CT-U and no medical history of urolithiasis. Patients with a medical history of diseases leading to higher risks on urolithiasis were excluded. In the nephrolithiasis group affected kidneys were measured. In the control group, left and right kidneys were alternately measured.

RESULTS

Twenty kidneys were measured in both groups. Mean calyceopelvic tract width was significantly larger in the lower segments of affected kidneys (3.9 vs. 2.7 mm). No significant differences between the groups were found in number of calyces, infundibular length, infundibular width, calyceopelvic angle, upper-lower angle and diameters of the pelvis. Transversal calyceal orientation in hours was significantly smaller in the upper and lower segments of the nephrolithiasis group (7.69 vs. 8.52 and 8.08 vs. 9.09 h), corresponding with more dorsally located calyces in stone-forming kidneys.

CONCLUSION

Pelvicalyceal anatomy differs between stone-forming and non-stone-forming kidneys. Understanding the pelvicalyceal system and etiology of stone formation can improve development of endourological techniques.

Prevention of recurrent urinary stone disease

PURPOSE OF REVIEW

Urinary stone disease (USD) is increasing in prevalence and recurrence is common. In pediatrics, most stones are composed primarily of calcium with the highest incidence observed in adolescents. Given the morbidity associated with USD, an in depth review of current management strategies is of paramount importance to highlight the data supporting the recommended treatments and the knowledge gaps which still exist.

RECENT FINDINGS

Several interventions for the management of recurrent calcium USD in children have been recommended based on primarily adult studies. These interventions include modification of diet and fluid intake in addition to the utilization of medications such as thiazide diuretics and citrates when supportive care is inadequate. Overall there is conflicting data in the adult literature which is further complicated by our attempts to extrapolate these data to children.

SUMMARY

Based on the currently available literature the management of USD in pediatrics should be individualized to each patient and focused on the particular metabolic risk factors that are identified during the course of their evaluation. Several interventions may be required or trialed in a particular patient to show an effect. Well designed trials to assess the efficacy of each intervention in the pediatric population are needed.

Correlation of Operative Time with Outcomes of Ureteroscopy and Stone Treatment: a Systematic Review of Literature

PURPOSE OF REVIEW

To present the latest evidence related to the impact of increased operative times in retrograde intrarenal surgery and identify possible important factors that can facilitate ureteroscopy procedures.

RECENT FINDINGS

Ureteroscopy constitutes the mainstay treatment of renal stones and is characterized by a huge variation in techniques and instrumentation. It has been suggested that increased operative times can mitigate the outcomes of the procedures by increasing complication rates. Nevertheless, little is known about the time limits, above which complications are likely to occur. Furthermore, complication rates in different procedure durations have not yet been assessed. Prolonged operative times are linked to increased complication rates in ureteroscopy. Stone complexity, patient risk factors, surgeon experience, bilateral surgery, and instrumentation constitute important factors that can hamper or facilitate a procedure and should be taken into account beforehand. Keeping procedural times below 90 min can dissuade potential predicaments and achieve improved stone-free rates.

Predictors of Urinary Infections and Urosepsis After Ureteroscopy for Stone Disease: a Systematic Review from EAU Section of Urolithiasis (EULIS)

PURPOSE OF REVIEW

To present the latest evidence related to the predictors of urinary tract infections (UTIs) and urosepsis after ureteroscopy (URS) for stone disease.

RECENT FINDINGS

Our review suggests that almost half of all post-URS complications are related to infectious complications although reported rates of urosepsis were low. The use of antibiotic prophylaxis, treatment of pre-operative UTI, and low procedural time seem to reduce this risk. However, the risk is higher in patients with higher Charlson comorbidity index, elderly patients, female gender, long duration of pre-procedural indwelling ureteric stents and patients with a neurogenic bladder and with high BMI. Infectious complications following ureteroscopy can be a source of morbidity and potential mortality. Although majority of these are minor, efforts must be taken to minimise them especially in high-risk patients. This includes the use of prophylactic antibiotics, limiting stent dwell and procedural time, prompt identification and treatment of UTI and urosepsis, and careful planning in patients with large stone burden and multiple comorbidities.

Sex differences in the therapy of kidney and ureteral stones

PURPOSE OF REVIEW

Better understanding of sex differences affecting urolithiasis may help us offer tailored treatment strategies to our patients.

RECENT FINDINGS

The incidence of urolithiasis is increasing and the male-to-female ratio has decreased from 3 : 1 to 1.3 : 1 between 1970 and 2000. In women, obesity has a larger effect on the risk of developing urolithiasis [odds ratio (OR) 1.35; 95% confidence interval (CI): 1.33-1.37] compared with men (OR 1.04; 95% CI: 1.02-1.06). Urolithiasis is a risk factor for coronary artery disease in men (risk ratio = 1.23; 95% CI: 1.02-1.49) and for stroke in women (risk ratio = 1.12; 95% CI: 1.03-1.21). Women tolerate cystoscopic stent removal and shock wave lithotripsy better than men. For shock wave lithotripsy menopaused women have reported lower visual analog scale scores than menstruating women (P < 0.001). Female sex was an independent predictor of stone impaction (OR 1.15; 95% CI: 1.03-1.27) and postoperative sepsis after ureteroscopy (OR 2.31; 95% CI: 1.14-4.37).

SUMMARY

The sex gap in urolithiasis is closing. The changing role of women in society and dietary habits can be responsible for this epidemiologic shift. Women show a higher threshold for pain during urologic procedures, but they suffer from infectious complications more than men. Urolithiasis is a risk factor for cardiovascular events in both sexes.

Preventing CKD in Developed Countries

Chronic kidney disease (CKD) is an important public health concern in developed countries because of both the number of people affected and the high cost of care when prevention strategies are not effectively implemented. Prevention should start at the governance level with the institution of multisectoral polices supporting sustainable development goals and ensuring safe and healthy environments. Primordial prevention of CKD can be achieved through implementation of measures to ensure healthy fetal (kidney) development. Public health strategies to prevent diabetes, hypertension, and obesity as risk factors for CKD are important. These approaches are cost-effective and reduce the overall noncommunicable disease burden. Strategies to prevent nontraditional CKD risk factors, including nephrotoxin exposure, kidney stones, infections, environmental exposures, and acute kidney injury (AKI), need to be tailored to local needs and epidemiology. Early diagnosis and treatment of CKD risk factors such as diabetes, obesity, and hypertension are key for primary prevention of CKD. CKD tends to occur more frequently and to progress more rapidly among indigenous, minority, and socioeconomically disadvantaged populations. Special attention is required to meet the CKD prevention needs of these populations. Effective secondary prevention of CKD relies on screening of individuals at risk to detect and treat CKD early, using established and emerging strategies. Within high-income countries, barriers to accessing effective CKD therapies must be recognized, and public health strategies must be developed to overcome these obstacles, including training and support at the primary care level to identify individuals at risk of CKD, and appropriately implement clinical practice guidelines.

Prevalence and characterization of urolithiasis in the Western region of Saudi Arabia

Objectives:

The main objective of this study is to determine the prevalence and risk factors of urolithiasis among the Saudi population in Makkah region.

Methods:

A cross-sectional survey was conducted on February 2017 in Makkah region (Makkah, Jeddah, and Taif). Data were obtained through direct interviews with participants, using an 18-questions-self-questionnaire, inquiring about demographic data (age, gender, weight, height, location, and occupation), educational level, history of renal stone disease (symptoms, modality of diagnosis, hospital admission, and previous treatment), and risk factors of stone formation such as family history and daily fluid intake.

Results:

A total of 1506 individuals were interviewed, including 82% from Makkah, 15.7% from Jeddah, and only 2.3% from Taif. The overall percentage of those diagnosed urolithiasis was 6.2%; including 6.6% males and 5.8% females (P = 0.06). Of those with stones, 5% were medically treated, 1.7% were hospitalized, and 1.2% were surgically managed for stones. There was a positive linear correlation between the prevalence of stones and participants' age group (r = 0.87, P = 0.01). More than 80% of participants were highly educated, which did not impact the prevalence of stones formation (P = 0.14). Urolithiasis was reported by 8.9% obese participants, 5.9% overweight, and 5.4% with normal body mass index (r = 0.68, P = 0.03). When stratified by jobs, stone prevalence significantly increased in retired participants (17.2%) than in workers (8.8%), followed by those without work (7.7%) and finally by students (3.3%) (P < 0.001). There was no significant difference between urolithiasis and type of drinking water (P = 0.62).

Conclusion:

The prevalence of urolithiasis in the Western region of Saudi Arabia has not changed much since the previous report, which was 30 years ago. It seems that the middle-aged population in their third decade of life, those who are overweight and obese people are at a high risk of developing urolithiasis.

Associations between ambient temperature and hepatobiliary and renal hospitalizations in California, 1999 to 2009

BACKGROUND

High ambient temperature has been linked to a number of types of morbidity, such as cardiovascular disease and dehydration. Fewer studies have explored specifically the relationship between ambient temperature and liver, kidney, and urinary system morbidity despite known biological impacts of extreme high temperatures on those systems.

OBJECTIVE

We assessed the relationship between temperature and hospitalizations related to selected renal system (urinary stones, urinary tract infections, septicemia, chronic kidney disease, and a composite of selected kidney diseases) and hepatobiliary (biliary tract disease, other liver diseases [e.g. cirrhosis], non-diabetic pancreatic disorders) ailments.

METHODS

We compiled data on daily hospitalization counts for hepatobiliary and renal system diseases in California for 1999 through 2009, and matched it with meteorological data. Relationships between temperature and admissions during the warm season (May-October) were assessed at the climate zone-level cumulative over 14 days following exposure using distributed lag non-linear models, with adjustment for time trends and relative humidity, then combined using random-effects meta-regression to create statewide estimates.

RESULTS

Higher mean temperatures in the warm season were associated with significant increases in renal admissions for urinary tract infection [% change per 10 °F: 7.3, 95% CI: 5.6, 9.1], septicemia [% increase: 2.9; 95% CI: 1.5, 4.3], urinary stones [% increase: 15.2; 95% CI: 10.3, 20.4], and composite kidney disease. Additionally, increased temperatures were linked to increased admissions for biliary tract disease, but lower risk of other liver diseases. Some differences in association by race/ethnicity and regional meteorology were observed.

CONCLUSIONS

Exposure to higher temperatures was associated with increased risk of multiple renal system hospitalization types, with additional links to specific hepatobiliary morbidities observed.

Characteristics of current digital single-use flexible ureteroscopes versus their reusable counterparts: an in-vitro comparative analysis

Background

Single-use flexible ureterorenoscopes (fURSs) have been recently introduced aiming to offer solutions to the sterilization, fragility and cost issues of the reusable fURSs. In order to be a viable alternative, the single-use scopes must prove similar capabilities when compared to their reusable counterparts. The goal of our in-vitro study was to compare the current reusable and single-use digital fURSs regarding their deflection, irrigation and vision characteristics.

Methods

We compared in-vitro 4 single-use fURSs-LithoVue™ (Boston Scientific, Marlborough, Massachusetts, USA), Uscope™ (Zhuhai Pusen Medical Technology Co. Ltd., Zhuhai, Guangdong Province, China), NeoFlex™ (NeoScope Inc, San Jose, California, USA) and ShaoGang™ (YouCare Technology Co. Ltd., Wuhan, China) versus 4 reusable fURSs-FLEX-X^c (Karl Storz SE & Co KG, Tuttlingen, Germany), URF-V2 (Olympus, Shinjuku, Tokyo, Japan), COBRA vision and BOA vision (Richard Wolf GmbH, Knittlingen, Germany). Deflection and irrigation abilities were evaluated with different instruments inserted through the working channel: laser fibres (200/273/365 µm), retrieval baskets (1.5/1.9/2.2 Fr), guide wires [polytetrafluoroethylene (PTFE) 0.038 inch, nitinol 0.035 inch] and a biopsy forceps. A scoring system was designed to compare the deflection impairment. Saline at different heights (40/80 cm) was used for irrigation. The flow was measured with the tip of the fURS initially straight and then fully deflected. The vision characteristics were evaluated (field of view, depth of field, image resolution, distortion and colour representation) using specific target models.

Results

Overall, the single-use fURSs had superior in-vitro deflection abilities than the reusable fURSs, in most settings. The highest score was achieved by NeoFlex™ and the lowest by ShaoGang™. PTFE guide wire had most impact on deflection for all fURSs. The 200 µm laser fibre had the lowest impact on deflection for the single-use fURSs. The 1.5 Fr basket caused the least deflection impairment on reusable fURSs. At the end of the tests, deflection loss was noted in most of the single-use fURSs, while none of the reusable fURSs presented deflection impairment. ShaoGang™ had the highest irrigation flow. Increasing the size of the instruments occupying the working channel led to decrease of irrigation flow in all fURSs. The impact of maximal deflection on irrigation flow was very low for all fURSs. When instruments were occupying the working channel, the single-use fURSs had slightly better in-vitro irrigation flow than the reusable fURSs. The field of view was comparable for all fURSs, with LithoVue™ showing a slight advantage. Depth of field and colour reproducibility were almost similar for all fURSs. ShaoGang™ and Uscope™ had the lowest resolution. FLEX X^c had the highest image distortion while LithoVue™ had the lowest. Partial field of view impairment was not for Uscope™ and ShaoGang™.

Conclusions

In-vitro, there are differences in technical characteristics of fURSs. It appears that single-use fURSs deflect better than their reusable counterparts. Irrespective of deflection, the irrigation flow of the single-use fURSs was slightly superior to the flow of the reusable fURSs. Overall, reusable fURSs had better vision characteristics than single-use fURSs. Further in-vivo studies might be necessary to confirm these findings.

Reusable flexible ureterorenoscopes are more cost-effective than single-use scopes: results of a systematic review from PETRA Uro-group

Clinical data suggest an equipoise between single-use (disposable) and reusable flexible ureterorenoscope (fURS) in terms of scope characteristics, manipulation, view and clinical outcomes. The procedural cost of reusable fURS is dependent on the initial and repair cost, maintenance and scope sterilization and on the number of procedures performed/repair. We conducted a systematic review on the procedural cost ($) of fURS based on the individual authors reported data on the number of procedures performed before repair and to see if it is a feasible option compared to single use fURS. A systematic review carried out in a Cochrane style and in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) checklist using Medline, Scopus, CINAHL, EMBASE and Cochrane library for all English language articles. All papers on fURS cost analysis were searched from 2000-2018 (19 years), which mentioned the cost of fURS based on the number of procedures performed and the repairs needed (procedure/repair) as reported by the individual authors. Six studies reported on both the number of procedures performed with number of repairs needed and the cost calculated/procedure in the given time period. The number of uses/repair in various studies varied between 8-29 procedures and the cost per procedure varied between $120-1,212/procedure. A significant trend was observed between the decreasing cost of repair with the number of usages. With studies reporting on a minimum of 20 cases/repair the mean cost was around $200/procedure. This is contrast to the disposable scopes such as Lithovue ($1,500-2,000/usage) and Pusen ($700/usage). The cost of reusable fURS is low in centres performing a high volume of procedures. Similarly, when a reasonable volume of procedures is performed before scope repair, the cost is lower than the disposable scopes. Although, the disposable and reusable scopes seem to be comparable in terms of their performance, this review proves that reusable fURS are still more cost effective than disposable scopes.

Role of pelvicalyceal anatomy in the outcomes of retrograde intrarenal surgery (RIRS) for lower pole stones: outcomes with a systematic review of literature

Controversies exist on the influence of lower pole anatomy (infundibular pelvic angle, IPA; infundibular length, IL; and infundibular width, IW) for success and outcomes related to the treatment of stones in the lower pole. We wanted to look at the role of lower pole anatomy to study clinical outcomes in patients treated for isolated lower pole stones (LPS) using retrograde intra renal surgery (RIRS), and also perform a review to look at the published literature on the influence of pelvicalyceal anatomy on success with RIRS. Data were prospectively collected (June 2013-June 2016) for all patients who underwent RIRS for LPS, and the imaging was then retrospectively reviewed to calculate the IPA, IL and IW using the Elbahnasy method. A systematic review was also conducted for all English language articles between January 2000 and April 2018, reporting on the impact of pelvicaliceal anatomy on RIRS. A total of 108 patients with LPS were included with a male to female ratio of 2:3 and a mean age of 54.7 years. The mean lower pole stone size was 9.3 mm (range 3-29 mm) and 102/108 (94.4%) patients were stone free (SF) at the end of their procedure. While steep IPA (< 30°), operative time duration and larger stone size were significant predictors of failure, the placement of ureteric access sheath, IW and IL did not influence treatment outcomes. Six studies (460 patients) met the inclusion criteria for our review. The IPA, IW, IL for failure ranged from 26° to 38°, 5.5-7 mm and 24-34 mm, respectively. The SFR ranged from 78 to 88% with a metaanalysis showing IPA as the most important predictor of treatment outcomes for LPS. Infundibular pelvic angle seems to be the most important predictor for the treatment of LPS using RIRS. Pelvicalyceal anatomy in conjunction with stone size and hardness seem to dictate the success, and decisions on the type of surgical interventions should reflect this.

Comparison of stone-free rates following shock wave lithotripsy, percutaneous nephrolithotomy, and retrograde intrarenal surgery for treatment of renal stones: A systematic review and network meta-analysis

OBJECTIVES

To perform a systematic review and network meta-analysis comparing stone-free rates following retrograde intrarenal surgery (RIRS), extracorporeal shock wave lithotripsy (SWL), and percutaneous nephrolithotomy (PCNL) treatments of renal stones.

MATERIALS AND METHODS

Clinical trials comparing RIRS, SWL, and PCNL for treatment of renal stones were identified from electronic databases. Stone-free rates for the procedures were compared by qualitative and quantitative syntheses (meta-analyses). Outcome variables are shown as risk ratios (ORs) with 95% credible intervals (CIs).

RESULTS

A total of 35 studies were included in this network meta-analysis of success and stone-free rates following three different treatments of renal stones. Six studies compared PCNL versus SWL, ten studies compared PCNL versus RIRS, fourteen studies compared RIRS versus SWL, and five studies compared PCNL, SWL, and RIRS. The quality scores within subscales were relatively low-risk. Network meta-analyses indicated that stone-free rates of RIRS (OR 0.38; 95% CI 0.22-0.64) and SWL (OR 0.12; 95% CI 0.067-0.19) were lower than that of PCNL. In addition, stone-free rate of SWL was lower than that of RIRS (OR 0.31; 95% CI 0.20-0.47). Stone free rate of PCNL was also superior to RIRS in subgroup analyses including ≥ 2 cm stone (OR 4.680; 95% CI 2.873-8.106), lower pole stone (OR 1.984; 95% CI 1.043-2.849), and randomized studies (OR 2.219; 95% CI 1.348-4.009). In rank-probability test, PCNL was ranked as No. 1 and SWL was ranked as No. 3.

CONCLUSIONS

PCNL showed the highest success and stone-free rate in the surgical treatment of renal stones. In contrast, SWL had the lowest success and stone-free rate.

'Negative Ureteroscopy' for Stone Disease: Evidence from a Systematic Review

PURPOSE OF REVIEW

While ureteroscopy (URS) is a common procedure for ureteric stones, this window between diagnosis and treatment leaves the possibility for a 'negative', 'stoneless' or 'diagnostic' URS. We perform a systematic review to look at the rate of 'negative ureteroscopy' and risk factors associated with it.

RECENT FINDINGS

From a total of 3599 articles and 68 abstracts, 4 studies (1336 patients) were selected. The negative URS rate varied from 4 to 14%. Common predictors seem to be female gender, small stones, radiolucent stones and distal ureteric stones. Although infrequent, negative ureteroscopy should be avoided in patients with ureteric stones by performing a low-dose CT scan on the day of surgery. This should especially be performed for females and those with smaller, radiolucent or distal ureteric stones.

Outcomes of Elective Ureteroscopy for Ureteric Stones in Patients with Prior Urosepsis and Emergency Drainage: Prospective Study over 5 yr from a Tertiary Endourology Centre

BACKGROUND

Elective treatment of ureteric stones is needed after emergency drainage of urosepsis.

OBJECTIVE

We wanted to look at the outcomes of elective ureteroscopic stone treatment in patients with prior sepsis and emergency drainage via retrograde ureteric stent (RUS) or percutaneous nephrostomy (PCN).

DESIGN, SETTING, AND PARTICIPANTS

Data of all patients who underwent elective ureteroscopy (URS) for stone disease over 5 yr (March 2012-December 2016) were prospectively collected.

INTERVENTION

Elective URS following previous emergency RUS or PCN.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Outcomes were collated for consecutive patients who underwent emergency drainage for urosepsis secondary to stone disease, followed by elective URS. Data was collected regarding patient demographics, stone parameters, and clinical outcomes. Statistical analysis was performed using SPSS version 24.

RESULTS AND LIMITATIONS

In total, 76 patients underwent 82 elective procedures (six underwent bilateral URS) with a male to female ratio of 1:2 and a mean age of 57 yr. Emergency decompression was achieved via RUS in 63 (83%) and PCN in 13 (17%) patients. A positive urine culture on presentation was obtained in 26 (34%) patients, and 27 (36%) patients were admitted to the intensive care unit (ICU). The mean single and overall stone size was 8.6 (2-23) and 10.8 (2-32) mm, respectively. The mean operating time was 42 (5-129) min with stone-free rate (SFR) of 97% (n=74). There were three (4%) complications in total, of which two patients developed urinary tract infection needing intravenous antibiotics (Clavien II) and a third developed sepsis (Clavien IV) needing ICU admission. There was no difference in ureteroscopic lithotripsy outcomes (operative time, complications, or SFR) on comparing initial RUS or PCN, admission to ICU or ward, positive or negative urine culture result, presence of single or multiple stones, and between American Society of Anaesthesiologists (ASA) grade of patients. The ASA grade of patients was a significant predictor of day case procedures (p=0.001).

CONCLUSIONS

Elective URS achieved excellent outcomes in patients who previously presented with obstructing calculi and sepsis needing emergency decompression. Overnight inpatient admission was needed in some patients with a higher ASA grade.

PATIENT SUMMARY

In this report, we look at the outcomes of planned ureteroscopy procedures for stone disease in patients with previous urosepsis. These patients with previous emergency drainage for urosepsis had excellent outcomes from their planned ureteroscopic surgery. This information will help in preoperative patient optimisation and counselling.

Variation in Kidney Stone Composition Within the United States

INTRODUCTION AND OBJECTIVES

Kidney stone incidence has been known to vary with temperature and climate. However, little is known about any variation in the composition of kidney stones across different regions of the United States. We attempted to evaluate whether stone composition changes depending on region.

METHODS

We were given access to de-identified data from LABCORPs database of kidney stone composition from August 1, 2016, to October 24, 2016, for states in seven representative areas of the country: Virginia, Minnesota, Florida, Arizona, Colorado, California, and Texas. We analyzed each component of kidney stones with optical microscopy supplemented with Fourier-transform infrared spectroscopy (FT-IR) spectrometry using both the percentage of the stone that was composed of that component as well as a binary variable coded none vs any. Univariate associations between component and state were examined using chi-square or Fisher's exact test for the binary indicator, and analysis of variance for the continuous percentage. The same set of analyses was used for decade of age vs each component. The association between age and state was examined using analysis of variance.

RESULTS

Data were available for 4335 kidney stones, from patients in the 7 states mentioned. The most common components across all stones were calcium oxalate monohydrate and calcium phosphate (both present in 93% of stones), calcium oxalate dihydrate (in 57% of stones), and uric acid (in 12% of stones). Stone composition did not vary widely across regions, except for uric acid stones, which were more prevalent in Florida compared to other states, with an odds ratio of 1.43 (95% confidence interval 1.12, 1.83).

CONCLUSION

Kidney stone composition does not vary widely by region within the United States. Although temperature and humidity play a role in stone incidence, there does not appear to be a large variation between different climates, with the exception of uric acid stone formation in Florida.

Role of Minimally Invasive (Micro and Ultra-mini) PCNL for Adult Urinary Stone Disease in the Modern Era: Evidence from a Systematic Review

Purpose of Review

The role of PCNL and the expertise surrounding it has expanded in recent decades. Miniaturisation of equipment and instrument size has formed a part of this innovation. Although an increasing number of studies have been performed on miniaturised PCNL (Mi-PCNL) recently, a critical appraisal on these is lacking. We therefore conducted a systematic review of the literature to evaluate the efficacy, safety and feasibility of Mi-PCNL techniques (< 15 Fr).

Recent Findings

A systematic review was conducted from 1990 to March 2017 on outcomes of Mi-PCNL [micro PCNL (m-PCNL) and ultra-mini PCNL (UMP)] in adult patients. Ten studies (three on m-PCNL and seven on UMP) were included in our study. Across the three studies, 118 patients (mean age 42.2 years, male to female ratio 1.3:1) underwent m-PCNL (4.8 Fr). For a mean stone size of 13.9 mm, a mean stone-free rate (SFR) was 89% and an overall complication rate was 15.2% [Clavien classification I (44%), II (28%), III (28%)], with no Clavien IV or V complications. Across the seven studies, 262 patients (mean age 49.4 years, male to female ratio 1.5:1) underwent UMP (13–14 Fr). For a mean stone size of 18.6 mm, a mean SFR was 88.3% and an overall complication rate was 6.2% [Clavien classification I (57%), II (36%), III (7%)], with no Clavien IV or V complications. While the transfusion rates for m-PCNL was 0.85%, only one case each in m-PCNL and UMP needed conversion to mini PCNL.

Summary

Our review shows that for small- to medium-sized renal stones, Mi-PCNL can yield good stone-free rates whilst maintaining a low morbidity associated with it. There were no Clavien > III complications and no mortality with only one transfusion reported from this minimally invasive technique.

Trends of 'urolithiasis: interventions, simulation, and laser technology' over the last 16 years (2000-2015) as published in the literature (PubMed): a systematic review from European section of Uro-technology (ESUT)

Purpose

To look at the bibliometric publication trends on ‘Urolithiasis’ and aspects of treatment and training associated with it over a period of 16 years from 2000 to 2015. To this end, we conducted this study to look at the publication trends associated with urolithiasis, including the use of simulation, laser technology, and all types of interventions for it.

Materials and methods

We performed a systematic review of the literature using PubMed over the last 16 years, from January 2000 to December 2015 for all published papers on ‘Urolithiasis’. While there were no language restrictions, English language articles and all non-English language papers with published English abstracts were also included. Case reports, animal and laboratory studies, and those studies that did not have a published abstract were excluded from our analysis. We also analyzed the data in two time periods, period-1 (2000–2007) and period-2 (2008–2015).

Results

During the last 16 years, a total of 5343 papers were published on ‘Urolithiasis’, including 4787 in English language and 556 in non-English language. This included papers on URS (n = 1200), PCNL (n = 1715), SWL (n = 887), open stone surgery (n = 87), laparoscopic stone surgery (n = 209), pyelolithotomy (n = 35), simulation in Endourology (n = 82), and use of laser for stone surgery (n = 406). When comparing the two time periods, during period 2, the change was +171% (p = 0.007), +279% (p < 0.001), and −17% (p = 0.2) for URS, PCNL, and SWL, respectively. While there was a rise in laparoscopic surgery (+116%), it decreased for open stone surgery (−11%) and pyelolithotomy (−47%). A total of 82 papers have been published on simulation for stone surgery including 48 papers for URS (67% rise in period-2, p = 0.007), and 34 papers for PCNL (480% rise in period-2, p < 0.001). A rising trend for the use of laser was also seen in period 2 (increase of 126%, p < 0.02, from 124 papers to 281 papers).

Conclusions

Published papers on intervention for Urolithiasis have risen over the last 16 years. While there has been a steep rise of URS and minimally invasive PCNL techniques, SWL and open surgery have shown a slight decline over this period. A similar increase has also been seen for the use of simulation and lasers in Endourology.