Effect of urinary stone disease and its treatment on renal function

Risk factors of stone residual after retrograde intrarenal surgery: A prospective cohort study

BACKGROUND

Complete removal of renal stones is crucial for optimal patient outcomes, but recent studies have reported residual stones after retrograde intrarenal surgery (RIRS). This study aimed to identify the associated risk factors to improve patient management and treatment selection.

METHODS

This cohort study was conducted over 18 months at two hospitals and recruited adult patients with renal stones less than 3 cm. Preoperative assessment included medical history, physical examination, laboratory tests, and radiological imaging. Intraoperative and postoperative data collection and follow-up were conducted to evaluate surgical success and potential complications.

RESULTS

A total of 100 patients were included, with a mean age of 45.3 ± 10.7 years and a mean BMI of 26.2 ± 1.4 kg/m2. Approximately 19% of the patients had residual stones after the RIRS procedure. The RUSS score showed good diagnostic performance with an AUC of 0.843, and the optimal cut point was ⩾2.0 with a sensitivity of 52.6% and specificity of 95.1%. Independent predictors of residual stones were multiple sites (OR = 24.98; p = 0.002), multiple stones (OR = 13.62, p = 0.002), stone size of 21-30 mm (OR = 4.91, p = 0.038), lower calyx site (OR = 4.85, p = 0.033), and surgeon experience of fewer than 50 cases (OR = 6.82, p = 0.020).

CONCLUSIONS

This study identifies several factors associated with residual stones after RIRS for renal stones, including stone size, location, number, and surgeon experience. The study suggests that the RUSS score can be used as a reliable tool for predicting the likelihood of residual stones, which can help clinicians in patient selection and treatment planning.

Prevention, diagnosis, and treatment of urolithiasis in geriatric patients - differences, similarities and caveats in comparison to the general population

PURPOSE OF REVIEW

Purpose of the review is to address management and prevention of urolithiasis in elderly patients examining the dynamic interplay between general measures, dietary adjustments, lifestyle modifications, and targeted pharmacological and/ or surgical interventions. The goal is to provide understanding of the evolving strategies required for effective urolithiasis prevention in the geriatric population.

RECENT FINDINGS

Age-specific diagnostic considerations are necessary because urolithiasis in the elderly population is characterized by bigger stones, greater peri-operative risks, and heightened symptom severity. When comorbidities are present, conservative treatments - especially analgesia - provide difficulties. Surgical procedures prove to be safe and effective, with complication rates and practical application comparable to younger cohorts. Prevention approaches that include lifestyle changes and the investigation of novel pharmaceutical options such as sodium-dependent glucose co-transporter 2 (SGLT-2)-inhibitors are promising in the management of urolithiasis in the elderly population.

SUMMARY

Our review offers a thorough investigation of urolithiasis in the elderly population, elucidating distinct clinical manifestations, complex diagnostic issues, and treatment implications. The safety and effectiveness of ureteroscopy in older patients, as well as the possible prophylactic function of SGLT-2-I, offer crucial insights for clinicians. Subsequent studies are necessary to enhance age-specific therapies, addressing the distinct obstacles presented by urolithiasis in the elderly population within this rapidly growing demographic.

Effect of acupressure on pain among older female patients undergoing extracorporeal shock wave lithotripsy: A randomized controlled clinical trial

BACKGROUND AND AIM

Urinary stones are highly prevalent among older people. Extracorporeal lithotripsy is one of the commonly used treatment methods, but it causes pain. Acupressure is a non-pharmacological therapeutic method that is effective in relieving pain among patients with various health conditions. This study aimed to investigate the effect of acupressure on pain among female older people undergoing extracorporeal lithotripsy.

METHOD

This randomized controlled clinical trial was conducted on 66 older female patients undergoing extracorporeal lithotripsy. They were enrolled in the study through convenient sampling and were assigned to the intervention and control groups through the block randomization method. The intervention group underwent acupressure for 16 min which was repeated twice with an interval of 20 min, but the control group received only touch without any pressure for the same period. The McGill Pain Questionnaire and Visual Analogue Scale were completed 60 min before the intervention and immediately after lithotripsy.

FINDINGS

Before the intervention, no statistically significant difference in the quality and intensity of pain between the two groups was observed (p > 0.05). However, after acupressure, the mean scores of quality and intensity of pain decreased significantly (p < 0.001) in the intervention group compared with the control group.

CONCLUSION

Acupressure as a complementary and alternative medicine can reduce pain and suffering among older people undergoing extracorporeal lithotripsy. It can be included in the routine therapeutic measures for relieving pain and suffering during noninvasive methods for older people and reducing their need for medication use and avoiding related pharmacological side effects.

Renal dysfunction in routine proton-pump inhibitor use may be linked to comorbidities: A real-world observational study

INTRODUCTION

The use of proton-pump inhibitors (PPI) is linked with infrequent but serious adverse events, including acute kidney injury, chronic kidney disease (CKD) and progression of CKD. Data on renal safety in routine use of PPI are more relevant to clinical practice. We studied whether such use of PPI is associated with renal dysfunction.

METHODS

Patients taking PPI for at least six weeks had serum creatinine tested pre (n = 200) and post (n = 180) recruitment. These patients were then advised to follow-up: those taking PPI for at least 90 days in the next six months (n = 77) and at least another 90 days in the following six months (n = 50), had serum creatinine tested at such follow-up. Renal dysfunction was defined as any increase in serum creatinine level above baseline.

RESULTS

The 200 patients recruited had mean age 39.6 (SD 9.2) years. Ninety-eight (49%) patients had a history of previous PPI use (median six months; interquartile range [IQR] 3-24). Only 20 (11.1%) patients at six weeks, 11 (14.3%) at six months and six (12%) at one year had increase in creatinine level; a majority of them had less than 0.3 mg/dL increase. Ten of these 20 (six weeks), five of 11 (six months) and five of six (one year) had other risk factors for renal dysfunction. No patient developed CKD during the study period.

CONCLUSIONS

Mild and non-progressive increase in serum creatinine occurred in 10% to 15% of patients on routine PPI use. A majority of them had other risk factors. Small sample size and short follow-up duration are a few limitations of this study.

A novel in vivo model of ureteral fibrosis induced by calcium oxalate beads in C57BL/6J mice

The global incidence of ureteroliths in humans is increasing, particularly posing a problem in developed countries. The most common stone type is calcium oxalate, which is associated with a high recurrence rate. In veterinary medicine, stones are the most common cause of ureteral obstruction in cats, accounting for 72-87% of cases. In cats, stones cause irreversible ureteral damage, necessitating stone treatment as well as ureteral therapy. However, the mechanisms underlying the ureteral damage caused by stones remain unclear. Therefore, this study aimed to create a mouse model suitable for studying the ureteral fibrosis caused by oxalate stones by artificially embedding calcium oxalate in the ureter. Pathological tissue analysis was used to compare normal ureters without ligation and ureters with sham or oxalate bead implantation. The ureters of the sham and oxalate bead groups showed granulation tissue formation, transitional epithelium exfoliation, and densely packed connective tissue in the proprietary and muscle layer regions. Particularly in the oxalate bead group, infiltration of degenerated neutrophils, presence of foreign body giant cells, and hyperplasia of the transitional epithelium were observed. The proportion of fibrosis was higher in the oxalate group than in the sham group. Overall, this mouse model created using oxalate bead implantation has the potential to efficiently induce ureteral obstruction. This mouse model is expected to be used for elucidating the molecular mechanisms of ureteral fibrosis and evaluating therapeutic drugs in future.

Stone disease in low-middle income countries. Could augmented reality have a role in its management?

Urolithiasis is a global phenomenon. Cystolithiasis is common in parts of Africa due to low protein intake and dehydration from endemic diarrhoeal illnesses. Nephrolithiasis is less prevalent than in high income countries, probably due to a variety of lifestyle issues, such as a more elemental diet, higher physical activity and less obesity. Although renal stones are less common in low-middle income countries (LMICs), the social and economic impacts of nephrolithiasis are still considerable; many stones present late or with complications such as upper urinary tract obstruction or urosepsis. These may lead to the development of chronic kidney disease, or end-stage renal failure in a small proportion of cases, conditions for which there is very poor provision in most LMICs. Early treatment of nephrolithiasis by the least invasive method possible can, however, reduce the functional consequences of urinary stone disease. Although ESWL is uncommon, and endoscopic interventions for stone are not widespread in most of Africa, percutaneous nephrolithomy and ureteroscopic renal surgery are viable techniques in those regional centres with infrastructure to support them. Longitudinal mentoring has been shown to be a key step in the adoption of these minimally invasive procedures by local surgeons, something that has been difficult during the COVID-19 pandemic due to travel restriction. Augmented reality (AR) technology is an alternative means of providing remote mentoring, something that has been trialled by Urolink, the MediTech Trust and other global non-governmental organisations during this period. Our preliminary experience suggests that this is a viable technique for promulgating skills in LMICs where appropriate connectivity exists to support remote communication. AR may also have long term promise for decreasing the reliance upon short-term surgical visits to consolidate competence, thereby reducing the carbon footprint of global surgical education.

Percutaneous nephrolithotomy versus extracorporeal shock wave lithotripsy for renal insufficiency

OBJECTIVE

To assess the effect and outcome of percutaneous nephrolithotomy (PNL) versus extracorporeal shock wave lithotripsy (SWL) in patients with renal insufficiency.

PATIENTS AND METHODS

A prospective randomized clinical study of 104 renal insufficiency patients with renal stones (serum creatinine 2-4 mg/dl and eGFR < 60 ml/min/1.73 m² more than 3 months) randomized into two groups: Group A underwent PNL; Group B underwent shock wave lithotripsy (SWL). Treatment effects and outcomes compared between the two groups.

RESULTS

Between Group A of 50 patients and Group B of 54 cases, demographic data showed no statistically significant differences. The stone-free rate was 84% in Group A versus 26.6% in Group B after the first SWL session. After completion of all SWL sessions, the rate was 88.9% for Group B. Comparing pre and postoperative results of Group A, there is significant improvement of serum creatinine concentrations by 9.1% (p = 0.001), significant improvement of creatinine clearance (p = 0.000) and eGFR (p = 0.003). Although regarding Group B preoperatively and 3 months after SWL there is significant improvement by 8.7% (p = 0.0001), which is less than that of Group A, there is also, improvement of eGFR by 6.7% (p = 0.001), which is less than the eGFR improvement in Group A (12.3%). But there is no statistically significant difference is noted for creatinine clearance in Group B (p = 0.09).

CONCLUSION

The outcomes for PNL and SWL in patients with renal insufficiency and renal stones are encouraging as minimally invasive procedures with no negative effects on kidney function.

Effect of Renal Function on Success and Complications of Percutaneous Nephrolithotomy

Objective: In this study, we aimed to compare the success and complication rates of percutaneous nephrolithotomy (PCNL) according to preoperative glomerular filtration rates (GFR) of patients who underwent PCNLdue to kidney stones. Material and Methods: Between January 2012 and December 2016, 794 patients who underwent PCNL due to kidney Stones were evaluated retrospectively. Preoperative GFR values of patients were calculated according to Cockcroft –Gault formula. The patients with preoperative GFR values>90 ml/min, 60-90 ml/min, 30-60 ml/min were respectively defined as group-1, group-2 and group-3. Preoperative and perioperative values, Stone free rates and complication rates were compared between the groups. Postoperatively , <4 mm residual stone was identified as success. Results: There were 466 patients in Group-1, 259 in Group-2 and 67 patients in Group-3. The mean preoperative GFR values of the patients were 118.53 ml/min, 77.76 ml/min and 48.52 ml/min, respectively in group-1, group-2 and group-3 (p <0.001).The mean age of the patients was 62.8±11.47, 51.86±11.10, and60.31±12.7, respectively, in group-1, group-2 and group-3 (p<0.001).The mean Stone burden of the patients were 497.34±518.60 mm2, 517.6±493.8 mm2and 711.06±679.07 mm2, respectively, in group-1, group-2 and group-3 (p=0.013). The number of patients identified with success after surgery was 355 (86.2%), 195 (76.1%) and 50 (74.6%) in group-1, group-2 and group-3, respectively (p = 0.542). The number of patients who develop complications was 114 (%24.65), 57 (%22) and 11 (%16.4) in group-1, group-2 and group-3, respectively (p=0.310). Conclusion: Preoperative GFR valuesare not lonely sufficient to predict success and complications after PCNL. Keywords: Percutaneous nephrolithotomy, renal function, renal stone, glomerular filtration rates

Effects of Selenized Astragalus Polysaccharide on the Adhesion and Endocytosis of Nanocalcium Oxalate Dihydrate after the Repair of Damaged HK-2 Cells

An oxidative damage model of human proximal renal epithelial cells (HK-2) was established using oxalate damage. The repair effects of Astragalus polysaccharide (APS) and selenized APS (Se-APS) on damaged HK-2 cells were investigated. Differences in the adhesion and endocytosis of HK-2 cells to calcium oxalate dihydrate crystals with a size of approximately 100 nm before and after APS and Se-APS repair were also explored. The results showed that after being repaired by APS and Se-APS, HK-2 cells exhibited increased cell viability, restored cell morphology, reduced reactive oxygen species level, increased mitochondrial membrane potential, reduced phosphatidylserine eversion, and osteopontin expression. Moreover, the amount of adherent crystals on the cell surface decreased, but the amount of endocytic crystals increased. At the same concentration, Se-APS exhibited better repair effects on the damaged HK-2 cells than APS. All these findings revealed that Se-APS may be a potential drug candidate for inhibiting the formation of kidney stones.

Management of urolithiasis in patients with chronic kidney disease

Context

Management of urolithiasis in patients with chronic kidney disease.

Aims

To ascertain the best method surgical or noninvasive.

Settings and Design

This was a single-institute study.

Subjects and Methods

A total of 50 patients of CKD with urolithiasis were enrolled in this comparative study. Clinical evaluation, biochemical evaluation, and radiological imaging were done. The management strategies were individualized to patient need. Following procedure, imaging and biochemical assessment were done to assess the stone clearance and improvement in the renal parameters. Intraoperative and postoperative complications are also noted. The patients were followed up to 6 months.

Statistical Analysis Used

Statistical Package for the Social Sciences version 21.0 software was used for statistical analysis.

Results

The mean age of the patients was 55.22 ± 10.76 years (range 28-76). Majority were male (76%) and had unilateral involvement. The mean preoperative hemoglobin (Hb), urea, creatinine, and total leukocyte count (TLC) were 9.49 ± 0.84 g%, 71.13 ± 24.09 mg/dl, 4.71 ± 2.45 mg/dl, and 8.67 ± 1.81 thousands/cumm, respectively. Percutaneous nephrolithotomy (PCNL) and ureteroscopic lithotripsy (URSL) were the most common procedures performed in 23 (46%) and 12 (24%) patients, respectively. In 5 (10%) patients, PCNL with URSL was used. The clearance rate for different techniques ranged from 40% (PCNL with URSL) to 91.7% (URSL alone). The overall clearance rate was 78.3%. Fever (40%) and deranged renal function test requiring hemodialysis (16%) were the most common postoperative complications. Postoperatively, a significant decline in the mean Hb, serum (S.) urea, and S. creatinine was observed. The mean TLC levels showed a significant increase. During follow-up, S. creatinine levels showed consistent decline. Auxiliary procedures were needed in six (12%) cases. There were two (4%) mortalities.

Conclusions

The management of urolithiasis among CKD patients requires individualized approaches. The selection of appropriate strategy results in good outcome and minimum complications.

Nephroprotective Effect of Pleurotus ostreatus and Agaricus bisporus Extracts and Carvedilol on Ethylene Glycol-Induced Urolithiasis: Roles of NF-κB, p53, Bcl-2, Bax and Bak

This study was designed to assess the nephroprotective effects of Pleurotus ostreatus and Agaricus bisporus aqueous extracts and carvedilol on hyperoxaluria-induced urolithiasis and to scrutinize the possible roles of NF-κB, p53, Bcl-2, Bax and Bak. Phytochemical screening and GC-MS analysis of mushrooms’ aqueous extracts were also performed and revealed the presence of multiple antioxidant and anti-inflammatory components. Hyperoxaluria was induced in Wistar rats through the addition of 0.75% (v/v) ethylene glycol in drinking water for nine weeks. The ethylene glycol-administered rats were orally treated with Pleurotus ostreatus and Agaricus bisporus aqueous extracts (100 mg/kg) and carvedilol (30 mg/kg) daily during the last seven weeks. The study showed that Pleurotus ostreatus, Agaricus bisporus and carvedilol all successfully inhibited ethylene glycol-induced histological perturbations and the elevation of serum creatinine, serum urea, serum and urinary uric acid, serum, urinary and kidney oxalate, urine specific gravity, kidney calcium, kidney NF-κB, NF-κB p65, NF-κB p50, p53, Bax and Bak expressions as well as serum TNF-α and IL-1β levels. Moreover, the treatment decreased the reduction in urinary creatinine, urinary urea, ratios of urinary creatinine to serum creatinine and urinary urea to serum urea, Fex Urea and Bcl-2 expression in kidney. In conclusion, although Pleurotus ostreatus and Agaricus bisporus extracts and carvedilol all significantly inhibited the progression of nephrolithiasis and showed nephroprotective effects against ethylene glycol-induced kidney dysfunction, Pleurotus ostreatus and Agaricus bisporus seemed to be more effective than carvedilol. Moreover, the nephroprotective effects may be mediated via affecting NF-κB activation, extrinsic apoptosis and intrinsic apoptosis pathways.

Endoscopic nephrolithotomy for the removal of complicated nephroliths in dogs and cats: 16 kidneys in 12 patients (2005-2017)

OBJECTIVE

To describe techniques and outcomes for dogs and cats undergoing endoscopic nephrolithotomy (ENL) for the removal of complicated nephroliths.

ANIMALS

11 dogs and 1 cat (n = 16 renal units) with complicated nephroliths that underwent ENL via a surgically assisted ENL approach (12 renal units) or a percutaneous nephrolithotomy approach (4 renal units) between December 2005 and June 2017.

PROCEDURES

Data were obtained from the medical records regarding preoperative, operative, and postoperative findings. Follow-up information on complications and outcomes was also collected.

RESULTS

Indications for nephrolith removal included massive calculi displacing parenchyma (n = 7), recurrent urinary tract infections (5), and ureteral outflow obstruction (4). Median nephrolith diameter was 2.5 cm (range, 0.5 to 5.7 cm). Nephrolith composition differed among patients; calcium oxalate was the most common type (n = 7 [including 2 mixed nephroliths containing ≥ 60% calcium oxalate]). Following ENL (median duration, 180 minutes), 15 of 16 renal units were completely nephrolith free. Procedure-related complications included renal puncture-associated hemorrhage requiring a blood transfusion (n = 1), renal capsule tear (1), and ureteral puncture (1); all were managed without adverse consequence. Five of 12 patients remained alive at the final follow-up (median, 557 days after ENL), and none died from the procedure.

CONCLUSIONS AND CLINICAL RELEVANCE

ENL as performed was safe and effective in removing complicated nephroliths in a renal-sparing manner for the patients in this study. This procedure requires technical training and could be considered for the treatment of complicated nephrolithiasis in dogs and possibly cats.

The left ureterocele and stone of calyceal diverticulum in the patient with bilateral incomplete duplex kidneys managed by flexible ureteroscopy: a case report and literature review

BACKGROUND

Duplex kidneys are one of the most common renal congenital abnormalities, mostly asymptomatic and of no clinical significance. There are little reports about the left ureterocele and stone of calyceal diverticulum in patients with bilateral incomplete duplex kidneys managed by flexible ureteroscopy.

CASE PRESENTATION

A 69-year-old Chinese woman was presented with left waist pain for 1 month. A preoperative computed tomography (CT) scan and intravenous pyelogram revealed the left ureterocele which located in the left ureterovesical junction, and stone of calyceal diverticulum which located in the upper kidney of left incomplete duplex kidneys. The ureterocele was confirmed in view of ureteroscopy and the holmium laser was used for the resection of ureterocele. It took us a lot of efforts to find out the stone because of diverticular neck stenosis. Fortunately, when diverticular neck stenosis was incised internally by holmium laser, the stone was discovered clearly and removed using the holmium laser and nitinol stone basket through flexible ureteroscopy. A double-J ureteral stent was inserted and remained in place for 1 month. The symptom disappeared postoperatively and no complications were developed during the placement of the stent. There were no stone residents observed on CT scan before removing the ureteral stent 1 month later.

CONCLUSIONS

Flexible ureteroscopy with holmium laser is feasible to manage the ureterocele and calyceal diverticulum stones in patients with bilateral incomplete duplex kidneys in one operation.

Effects of flexible ureteroscopy on kidney: A prospective clinical trial

OBJECTIVE

To investigate the effects of flexible ureteroscopy (F-URS) on the operated side of a kidney by assessing the renal damage markers, urine neutrophil gelatinase-related lipocalin (NGAL) and serum cystatin-C (Cys-C), and overall kidney function with the measurements of standard serum creatinine and urine albumin and protein levels.

MATERIAL AND METHODS

A total of 30 patients who underwent F-URS for treatment of upper urinary stone disease were prospectively evaluated. Preoperative serum urea, creatinine, and Cys-C levels were noted. Levels of urine albumin, protein, creatinine, and NGAL in spot urine samples from the operated side of a kidney obtained through the access sheath preoperatively and through the ureteral catheter 1 and 24 hours postoperatively were also measured. Preoperative and postoperative parameter levels were statistically compared.

RESULTS

The patients' mean age was 46.6±15.9 years. The mean operative and fluoroscopy times were 90.67±32.5 and 3.15±1.43 minutes, respectively. The urine creatinine, albumin, protein, albumin/creatinine, and protein/creatinine levels were similar in preoperative and postoperative periods. Postoperative serum urea, creatinine, and Cys-C levels and urine NGAL and NGAL/creatinine levels were not also found with remarkable changes from the baseline levels.

CONCLUSION

F-URS is a safe therapeutic intervention in the treatment of urolithiasis, especially regarding renal damage, and functional outcomes.

Pathological Mineralization: The Potential of Mineralomics

Pathological mineralization has been reported countless times in the literature and is a well-known phenomenon in the medical field for its connections to a wide range of diseases, including cancer, cardiovascular, and neurodegenerative diseases. The minerals involved in calcification, however, have not been directly studied as extensively as the organic components of each of the pathologies. These have been studied in isolation and, for most of them, physicochemical properties are hitherto not fully known. In a parallel development, materials science methods such as electron microscopy, spectroscopy, thermal analysis, and others have been used in biology mainly for the study of hard tissues and biomaterials and have only recently been incorporated in the study of other biological systems. This review connects a range of soft tissue diseases, including breast cancer, age-related macular degeneration, aortic valve stenosis, kidney stone diseases, and Fahr’s syndrome, all of which have been associated with mineralization processes. Furthermore, it describes how physicochemical material characterization methods have been used to provide new information on such pathologies. Here, we focus on diseases that are associated with calcium-composed minerals to discuss how understanding the properties of these minerals can provide new insights on their origins, considering that different conditions and biological features are required for each type of mineral to be formed. We show that mineralomics, or the study of the properties and roles of minerals, can provide information which will help to improve prevention methods against pathological mineral build-up, which in the cases of most of the diseases mentioned in this review, will ultimately lead to new prevention or treatment methods for the diseases. Importantly, this review aims to highlight that chemical composition alone cannot fully support conclusions drawn on the nature of these minerals.

Measurement of Glomerular Filtration Rate using Quantitative SPECT/CT and Deep-learning-based Kidney Segmentation

Quantitative SPECT/CT is potentially useful for more accurate and reliable measurement of glomerular filtration rate (GFR) than conventional planar scintigraphy. However, manual drawing of a volume of interest (VOI) on renal parenchyma in CT images is a labor-intensive and time-consuming task. The aim of this study is to develop a fully automated GFR quantification method based on a deep learning approach to the 3D segmentation of kidney parenchyma in CT. We automatically segmented the kidneys in CT images using the proposed method with remarkably high Dice similarity coefficient relative to the manual segmentation (mean = 0.89). The GFR values derived using manual and automatic segmentation methods were strongly correlated (R2 = 0.96). The absolute difference between the individual GFR values using manual and automatic methods was only 2.90%. Moreover, the two segmentation methods had comparable performance in the urolithiasis patients and kidney donors. Furthermore, both segmentation modalities showed significantly decreased individual GFR in symptomatic kidneys compared with the normal or asymptomatic kidney groups. The proposed approach enables fast and accurate GFR measurement.

Minimally invasive percutaneous nephrolithotomy improves stone-free rates for impacted proximal ureteral stones: A systematic review and meta-analysis

Background

Urinary stones are common medical disorders and the treatment of impacted proximal ureteral stones (IPUS) is still a challenge for urologists. The aim of this study was to compare the efficacy and safety of minimally invasive percutaneous nephrolithotomy (MI-PCNL) and ureteroscopic lithotripsy (URL) in the treatment of IPUS via a meta-analysis.

Methods

We collected studies using PubMed, Embase, and Cochrane Library from 1978 to November 2016 and analyzed them using Stata 12.0 and RevMan 5.3. Odds ratios (ORs) and standard mean difference (SMD) were calculated for binary and continuous variables respectively, accompanied with 95% confidence intervals (CIs). All study procedures followed the PRISMA guidelines.

Results

Five prospective studies were included in our meta-analysis, with 242 MI-PCNL and 256 URL cases. MI-PCNL was associated with a longer postoperative hospital stay than URL (SMD, 3.14; 95% CI, 1.27 to 5.55). However, no significant difference was observed in operative time (SMD, -0.38; 95% CI, -3.15 to 2.38). In addition, MI-PCNL had higher initial (OR, 11.12; 95% CI, 5.56 to 22.24) and overall stone-free rates (OR, 8.70; 95% CI, 3.23 to 23.45) than URL, along with lower possibilities of surgical conversion (OR, 0.11; 95% CI, 0.03 to 0.49) and postoperative shock wave lithotripsy (OR, 0.06; 95% CI, 0.02 to 0.18). Regarding complications, no significant differences were observed between MI-PCNL and URL (OR, 1.39; 95% CI, 0.93 to 2.10), except for hematuria (OR, 4.80; 95% CI, 1.45 to 15.94).

Conclusions

MI-PCNL is optimal and should be considered as the preferred treatment method for IPUS, as it has better efficacy and a safety profile similar to that of URL. However, further high quality studies with larger sample size are required in future.

Renal tubular injury induced by ischemia promotes the formation of calcium oxalate crystals in rats with hyperoxaluria

Hyperoxaluria and cell injury are key factors in urolithiasis. Oxalate metabolism may be altered by renal dysfunction and therefore, impact the deposition of calcium oxalate (CaOx) crystals. We investigated the relationship of renal function, oxalate metabolism and CaOx crystal deposition in renal ischemia. One hundred male Sprague-Dawley rats were randomly divided into four groups. Hyperoxaluria model (Group A and B) was established by feeding rats with 0.75 % ethylene glycol (EG). The left renal pedicle was clamped for 30 min to establish renal ischemia Groups (B and C), while Groups A and D underwent sham operation. Then, serum and urine oxalate (Ox), creatinine (Cr) and urea nitrogen (UN) levels were evaluated by liquid chromatography mass spectrometry (LCMS) and ion mass spectrum (IMS) at days 0, 2, 4, 7, and 14. CaOx crystallization was assessed by transmission electron microscope (TEM). A temporal and significant increase of serum Cr and UN levels was observed in Groups B and C compared to values obtained for Groups A and D (P < 0.05). Ox levels in serum and urine were significantly higher in Groups A and B than in the other two groups from day 7 (P < 0.05). In addition, CaOx crystallization was observed in both Groups A and B, but Group B showed earlier and more pronounced crystal deposition in the renal tissue. Our results indicated that renal tubular injury induced by renal ischemia might not affect Ox levels but could promote CaOx crystal retention under hyperoxaluria.

Safety and feasibility of day case ureteroscopy and laser lithotripsy (URSL) in patients with a solitary kidney

Introduction

The management of nephrolithiasis in patients with a solitary kidney poses a treatment challenge. The study aimed to evaluate the outcomes of ureteroscopy and laser stone fragmentation (URSL) for renal stones in these patients treated in our university teaching hospital.

Material and methods

Between July 2012 and December 2014, seventeen cases of URSL for stones in a solitary kidney were reviewed. Patient demographics, stone dimensions, perioperative and post-operative outcomes were recorded in a prospectively maintained database. Serum creatinine levels pre-procedure and at follow-up were also compared.

Results

Seventeen cases of URSL were conducted with a mean age of 52.9 ±19.9 years. 8 of the 17 (47%) patients had stones in multiple locations and 13 (76%) were in the lower pole. The mean ± SD stone size and BMI were 13.0 ±8.9 mm and 31.6 ±5.8 kg/m², respectively. The stone free rate (SFR) was 82.5%. Fourteen (82.5%) patients were discharged the same day and 16 cases (94%) were discharged within 24 hours. For patients with deranged pre-operative serum creatinine, the mean serum creatinine level improved from 131.2 ±68.3 µmol/L pre-URSL to 106.5 ±36.7 µmol/L at follow-up. There was one Clavien grade II complication with a patient requiring additional antibiotics for post-operative urinary tract infection. There were no other major or minor complications.

Conclusions

Day case ureteroscopy for stone disease in a solitary kidney is safe and feasible with a low complication rate and an overall improvement in renal function.