The influence of prior laparoscopic experience on learning laparoendoscopic single site surgery: a prospective comparative preliminary study using cystorraphy in a live porcine model.

BACKGROUND: The purpose of this study is to assess the impact of prior laparoscopic experience on the ability to learn laparoendoscopic single site surgery (LESS) skills. METHODS: A total of 33 urologists who completed a training program in LESS surgery were recruited for this study. After completing the educational course and training, the study participants demonstrated LESS suturing and knot-tying via a 2-cm cystotomy in a live porcine model for 15 min. An objective structured assessment of technical skills (OSATS) was used to evaluate videos of each participant's procedure. The participants were divided according to laparoscopic experience; advanced experienced group (AS), intermediate experienced group (IS), novice group (NS). RESULTS: Three participants in the NS group completed the porcine cystorrhaphy in 15 min (30.0%), 3 (25.0%) completed the task in the IS group, and 3 (27.2%) completed it in the AS group. There were no statistically significant differences in the mean total OSATS quality score (NS; 16.7, IS; 18.5, AS; 16.8) among the 3 groups. Concerning all each assessment, there were also no statistically significant difference. Additionaly, the mean total OSATS quantity score (NS; 4.1, IS; 3.5, AS; 4.3) did not differ significantly among groups. The NS group succeeded a mean of 1.4 knots, the IS group succeeded 0.9, and the AS group 1.3 (p = 0.727). CONCLUSIONS: There was no significant difference among the groups in LESS proficiency after training. Surgeons who were novices in conventional laparoscopic surgery reached comparable scores to those of experienced laparoscopic surgeons after training.

Ileal Augmentation Cystoplasty Combined with Ileal Ureter Replacement After Radical Treatment for Cervical Cancer.

BACKGROUND: This study reviewed the outcomes for patients who underwent simultaneous bladder and ureter reconstructive surgery using the ileum after radical treatment for cervical cancer. METHODS: The medical records of seven patients who underwent augmentation ileocystoplasty with ileal ureter replacement between September 2006 and May 2013 were reviewed. Data on indications for surgery, underlying urologic comorbidities, type of ureteral replacement, postoperative complications, and changes in renal function were obtained. RESULTS: The median age of the patients was 56 years. The primary tumor was cervical cancer in all the patients, and the majority of the patients (4/7, 57.1 %) were previously treated with radical hysterectomy plus radiotherapy. Ileal ureter replacement was performed on 11 renal units, and bilateral ileal ureter substitution was performed for four patients, with the largest ureteral defect being 15 cm. The median length of the ileum used for augmentation and ureter substitution was 30 cm (range 15-40 cm), and the median hospital stay was 23 days (range 18-47 days). The overall rate of major complications (grade ≥3) was 57.1 % (4 of 7 patients). The median preoperative and immediate postoperative serum creatinine levels were respectively 1.2 mg/dL and 0.9 mg/dL. During a mean follow-up duration of 38 months, none of the patients experienced deterioration of renal function after surgery. CONCLUSION: Ileal ureter substitution combined with augmentation ileocystoplasty is a useful surgical technique for bridging long ureteral defects caused by ureteric stenosis from surgery, radiotherapy, or both for pelvic tumors in contracted low-compliance bladders.

Effect of perioperative tamsulosin on successful ureteral access sheath placement and stent-related symptom relief: A double-blinded, randomized, placebo-controlled study.

PURPOSE: This study investigated the effect of administering tamsulosin before surgery on the successful insertion of a 12/14 French (F) ureteral access sheath (UAS) during the procedure, as well as the impact of preoperative and postoperative tamsulosin use on symptoms related to the ureteral stent. MATERIALS AND METHODS: This study was a randomized, single-center, double-blinded, placebo-controlled trial involving 200 patients who underwent unilateral retrograde intrarenal surgery. Patients received either tamsulosin (0.4 mg) or placebo 1 week before surgery until stent removal. Patients were randomly assigned to one of four groups. Group 1 received tamsulosin throughout the study period. Group 2 received tamsulosin before surgery and placebo after surgery. Group 3 received placebo before surgery and tamsulosin after surgery. Group 4 received placebo before and after surgery. The USSQ (Ureteral Stent Symptom Questionnaire) was completed between postoperative days 7 and 14 immediately before stent removal. RESULTS: A total of 160 patients were included in this analysis. Their mean age was 55.0±11.0 years, and 48 patients (30.0%) were female. In the group that received preoperative tamsulosin, the success rate of 12/14F UAS deployment was significantly higher than that of the preoperative placebo group (88.0 vs. 75.3%, p=0.038). Preoperative and postoperative tamsulosin did not significantly alleviate symptoms related to the ureteral stent. CONCLUSIONS: Our results revealed that preoperative administration of tamsulosin improved the success of larger-sized UAS, whereas preoperative and postoperative tamsulosin use did not significantly alleviate symptoms related to ureteral stents.

Cystoscopic injection of N-butyl-2-cyanoacrylate followed by fibrin glue for the treatment of persistent or massive vesicourethral anastomotic urine leak after radical prostatectomy.

OBJECTIVES: Vesicourethral anastomotic urine leak is a common postoperative complication of radical prostatectomy. Herein we describe a novel method for the treatment of this complication. METHODS: Intervention for a prolonged or massive anastomotic urine leak was required in 10 out of 1828 patients (0.5%) submitted to radical prostatectomy between 2007 and 2011. N-butyl-2-cyanoacrylate (Histoacryl) followed by fibrin glue (Greenplast) were injected under local anesthesia into vesicourethral anastomotic gaps under fluoroscopic guidance using a 20-Fr rigid cystoscope. Cystograms were taken in all patients to confirm complete urine leak resolution before the removal of the urethral catheter. RESULTS: Cystoscopic injection of Histoacryl followed by fibrin glue was technically successful and well tolerated in all patients. The mean time from radical prostatectomy to glue injection was 16.0 days (range 12-27 days). Urethral catheterization was required for an average of 7.7 days after cystoscopic injection of fibrin glue (range 3-13 days). These measures ultimately enabled complete resolution of the urine leak in all cases. At a mean follow up of 23.3 months, all 10 patients were fully continent. The mean time to recovery of urinary continence was 20.4 weeks (range 3.9-60.0 weeks). CONCLUSIONS: Cystoscopic injection of N-butyl-2-cyanoacrylate followed by fibrin glue into the anastomotic gap is both a feasible and effective solution in patients with a persistent or massive vesicourethral anastomotic urine leak after radical prostatectomy.

Deep-Learning Segmentation of Urinary Stones in Noncontrast Computed Tomography.

Background: Noncontrast CT (NCCT) relies on labor-intensive examinations of CT slices to identify urolithiasis in the urinary tract, and, despite the use of deep-learning algorithms, false positives remain. Materials and Methods: A total of 410 NCCT axial scans from patients undergoing surgical treatment for urolithiasis were used for model development. The deep learning model was customized to combine a urolithiasis segmentation with per-slice classification for screening. Prediction models of the axial, coronal, and sagittal views were trained, and an additive model with an intersection of the coronal and sagittal predictions added to the axial outcome was introduced. Automated quantification of clinical metrics was evaluated in three-dimensional models of urinary stones. Results: The axial model detected 88.92% of urinary stones and produced a dice similarity coefficient of 87.56% in the urolithiasis segmentation. For urolithiasis (>5 mm), the sensitivity of the axial model reached 95.10%. False positives were reduced to 0.34 per patient using an ensemble of individual models. The additive model improved the sensitivity to 90.97% by detecting more small urolithiasis (<5 mm). All clinical metrics of size, long-axis diameter, volume, mean stone density, stone heterogeneity index, and skin-to-stone distance showed a strong correlation of R2 > 0.964. Conclusions: The proposed system could reduce the burden on the physician for imaging diagnosis and help determine treatment strategies for urinary stones through automated quantification of clinical metrics with high accuracy and reproducibility.

Efficacy and Safety of Human Bone Marrow-Derived Mesenchymal Stem Cells according to Injection Route and Dose in a Chronic Kidney Disease Rat Model.

Background and Objectives: We compared the efficacy and safety of human bone marrow-derived mesenchymal stem cells (hBMSC), delivered at different doses and via different injection routes in an animal model of chronic kidney disease. Methods and Results: A total of ninety 12-week-old rats underwent 5/6 nephrectomy and randomized among nine groups: sham, renal artery control (RA-C), tail vein control (TV-C), renal artery low dose (RA-LD) (0.5×106 cells), renal artery moderate dose (RA-MD) (1.0×106 cells), renal artery high dose (RA-HD) (2.0×106 cells), tail vein low dose (TV-LD) (0.5×106 cells), tail vein moderate dose (TV-MD) (1.0×106 cells), and tail vein high dose (TV-HD) (2.0×106 cells). Renal function and mortality of rats were evaluated after hBMSC injection. Serum blood urea nitrogen was significantly lower in the TV-HD group at 2 weeks (p<0.01), 16 weeks (p<0.05), and 24 weeks (p<0.01) than in the TV-C group, as determined by one-way ANOVA. Serum creatinine was significantly lower in the TV-HD group at 24 weeks (p<0.05). At 8 weeks, creatinine clearance was significantly higher in the TV-MD and TV-HD groups (p<0.01, p<0.05) than in the TV-C group. In the safety evaluation, we observed no significant difference among the groups. Conclusions: Our findings confirm the efficacy and safety of high dose (2×106 cells) injection of hBMSC via the tail vein.

Air-Permeable Waterproofing Electrocardiogram Patch to Monitor Full-Day Activities for Multiple Days.

On-skin healthcare patch-type devices have great technological challenges in monitoring full-day activities and wearing for multiple days without detachment. These challenges can be overcome when the sensor is air permeable but waterproof. This study presents a light-weight, highly stable, and stretchable Au electrode that is fabricated by sputtering on an imidized nanofiber mat. The contact surface of the electrode is hydro-wetting and the outer surface of the electrode is hydrophobic, so the porous electrode simultaneously has excellent sweat permeability and waterproofing capabilities. The electrode is applied to the electrocardiogram sensor for monitoring the cardiac signals for five consecutive days without detaching while doing various full-day activities such as relaxing, exercising, showering, and sleeping. This study suggests a modular setup of the electrodes and the cardiac signal processing unit for activating the device when cardiac monitoring is required.

The usefulness and ergonomics of a new robotic system for flexible ureteroscopy and laser lithotripsy for treating renal stones.

PURPOSE: To investigate the usefulness and ergonomics of a newly developed robotic system for flexible ureteroscopy (easyUretero). MATERIALS AND METHODS: During in vitro testing, six participants performed renal stone removal four times in an artificial kidney-ureter-bladder model. Each participant manipulated a single-use digital flexible ureteroscope (LithoVue) with their hands and the robotic system, sequentially. We compared the task completion times of each participant. The ergonomics of and operational satisfaction with each procedure were assessed by questionnaires. In vivo tests evaluated the operability and safety of the robotic system in two live female pigs. We checked that all the steps of flexible lithotomy for renal stones could be completed individually. RESULTS: The task completion time with the robotic system during in vitro testing was significantly longer than with manual ureteroscopy regardless of the operator's competence level (expert professors: 282.6±92.4 seconds vs. 73.6±43.3 seconds, p<0.001; fellows: 247.5±57.7 seconds vs. 95.8±43.7 seconds, p<0.001; residents: 281.3±111.0 seconds vs. 188.6±138.6 seconds, p<0.001). The residents took more time to remove the upper and mid caliceal stones with the robotic system. The ergonomic evaluation was better for the robotic system, but operational satisfaction was lower, and there was no statistical difference among the groups. In vivo tests showed that all the steps of robotic flexible ureteroscopy could be completed without difficulty. No safety issues were encountered during the procedure. CONCLUSIONS: The robotic system (easyUretero) was ergonomic and safe for flexible ureteroscopy and laser lithotripsy for renal stones.

Followup of unilateral renal function after laparoscopic partial nephrectomy.

PURPOSE: We assessed the change in unilateral renal function after laparoscopic partial nephrectomy to determine factors affecting the course and factors predicting the postoperative glomerular filtration rate decrease. MATERIALS AND METHODS: From prospectively collected data on 116 patients who underwent laparoscopic partial nephrectomy we evaluated the glomerular filtration rate of the operated kidney using diethylenetriaminepentaacetic acid scans done preoperatively, and 3 months, and 1, 2 and 3 years postoperatively. Kidney volume was measured from the arterial phase of dynamic computerized tomography of the kidney done before and 3 months postoperatively to calculate the volume reduction. We analyzed clinicopathological and operative factors with the potential to influence the perioperative glomerular filtration rate decrease. RESULTS: In all patients the glomerular filtration rate was significantly decreased by 3 months postoperatively. It remained significantly lower compared to preoperative function despite the trend toward progressive recovery, which was noted until 3 years postoperatively. Recovery in individuals was significantly influenced by patient age (less than 55 vs 55 years or greater), medical comorbidities, tumor size (less than 2.5 vs 2.5 cm or greater), kidney volume reduction (less than 20% vs 20% or greater) and collecting system repair at surgery. Independent determinants of postoperative renal function were the preoperative glomerular filtration rate (ß = 0.410, 95% CI 0.424-1.084; p <0.001), the percent of renal parenchymal volume reduction (ß = 0.273, 95% CI 0.168-0.766; p = 0.003) and pelvicalyceal system repair (ß = 0.284, 95% CI 2.960-15.788; p = 0.005). CONCLUSIONS: Function of the kidney undergoing laparoscopic partial nephrectomy progressively recovers after a significant decrease immediately after surgery. Although recovery differs according to patient age, comorbidities and tumor size, factors that independently predicted the postoperative glomerular filtration rate decrease were the renal parenchymal volume reduction and pelvicalyceal system repair.

Association between metabolic syndrome and the presence of kidney stones in a screened population.

BACKGROUND: Components of metabolic syndrome have been associated with kidney stone disease, but little evidence is available to support a relationship between metabolic syndrome and kidney stone development in healthy large screened populations. STUDY DESIGN: Cross-sectional analysis. SETTING & PARTICIPANTS: Data were obtained from 34,895 individuals who underwent general health screening tests between January 2006 and December 2006 at the Asan Medical Center. PREDICTOR: Metabolic syndrome was defined according to criteria established by the National Cholesterol Education Program Adult Treatment Panel III, American Heart Association, and National Heart, Lung, and Blood Institute. OUTCOMES & MEASUREMENTS: The presence of kidney stones was evaluated using computed tomography or ultrasonography. RESULTS: Of all those screened, 839 (2.4%) had radiologic evidence of kidney stones and metabolic syndrome was diagnosed in 4,779 (13.7%). The multivariable-adjusted OR for kidney stones increased with an increasing quintile of waist circumference and systolic/diastolic blood pressure (P < 0.001). Age, sex, hypertension, and metabolic syndrome status were independent risk factors for kidney stones. The presence of metabolic syndrome had an OR of 1.25 (95% CI, 1.03-1.50) for kidney stone prevalence. In participants with hypertension, the OR for the presence of kidney stones was 1.47 (95% CI, 1.25-1.71) compared with that for participants without hypertension after adjustment for other variables. LIMITATIONS: Cross-sectional design, absence of stone composition. CONCLUSION: Metabolic syndrome is associated with a significantly increased risk of kidney stone development. Our findings suggest the need for interventional studies to test the effects of preventing and treating metabolic syndrome on the risk of kidney stone development.

Effect of output voltage distribution on stone comminution efficiency during shockwave lithotripsy in renal or ureteropelvic junction stones: a preliminary study.

OBJECTIVE: This study evaluated stone comminution efficiency according to the distribution of the lithotripter output voltage during extracorporeal shockwave lithotripsy (SWL) of renal or ureteropelvic junction (UPJ) stones. MATERIAL AND METHODS: Sixty-two patients with a single radiopaque renal or UPJ stone of surface area about 50-400 mm(2) were prospectively randomized to receive a total of 2400 shocks per session according to one of three shock protocols: group A, output voltage was increased from 25% to 35% to 45% with 800 shocks per voltage; group B, constant output voltage of 35%; group C, decreasing output voltage from 45% to 35% to 25%. SWLs were carried out using a fourth generation electroconductive lithotripter, the Sonolith Vision, without anesthesia. The stone-free (SF) and success (SF + clinically insignificant residual fragment) rates were assessed. RESULTS: Patient demographics, body mass index, stone burden, laterality and stone locations were comparable among the three groups. There were no differences in the cumulative success rates (30%, 32% and 35% after the first session for groups A, B and C, respectively; 65%, 50% and 65% after the second session; and 80%, 68% and 75% after the third session). The cumulative SF rates and complications showed no differences among the three groups. CONCLUSIONS: In this preliminary study, manipulation of the lithotripter output voltage distribution did not affect stone comminution efficiency for renal or UPJ stones. This finding should be confirmed by larger studies including more patients.

Effect of Processing Route on Microstructure and Mechanical Properties in Single-Roll Angular-Rolling.

This paper reports the effect of the processing route on the microstructure and mechanical properties in the pure copper sheets processed by single-roll angular-rolling (SRAR). The SRAR process was repeated up to six passes in two processing routes, called routes A and C in equal-channel angular pressing. As the number of passes increased, the heterogeneous evolution of hardness and microstructural heterogeneities between the core and surface regions gradually became intensified in both processing routes. In particular, route A exhibited more prominent partial grain refinement and dislocation localization on the core region than route C. The finite element analysis revealed that the intense microstructural heterogeneities observed in route A were attributed to effective shear strain partitioning between the core and surface regions by the absence of redundant strain. On the other hand, route C induced reverse shearing and cancellation of shear strain over the entire thickness, leading to weak shear strain partitioning and delayed grain refinement. Ultimately, this work suggests that route A is the preferred option to manufacture reverse gradient structures in that the degree of shear strain partitioning and microstructural heterogeneity between the core and surface regions is more efficiently intensified with increasing the number of passes.

Factors influencing renal function reduction after partial nephrectomy.

PURPOSE: We investigated factors determining the degree of functional reduction by measuring changes in individual renal function before and after partial nephrectomy. MATERIALS AND METHODS: In 117 patients who underwent elective partial nephrectomy the glomerular filtration rate of the renal units with tumor from the diethylenetetramine pentaacetic acid renal scan was measured before and at a mean of 6.5 months after surgery. Kidney volume was calculated using computerized tomography. Of these patients 52 and 65 underwent open and laparoscopic partial nephrectomy, respectively. Satinsky clamps were used for renal artery-vein clamping in all patients. We analyzed patient, tumor and perioperative characteristics including surgical method with respect to changes in glomerular filtration rate. RESULTS: Renal cell carcinoma was diagnosed in 101 (86.3%) patients. Between the laparoscopic and open partial nephrectomy groups significant differences were noted in tumor size (2.14 vs 3.72 cm, p <0.001) and warm ischemia time (33.5 vs 20.5 minutes, p <0.001). Reduction and percent reduction in glomerular filtration rate (13.3 vs 12.6 ml per minute per m(2), p = 0.662; 29.9% vs 33.2%, p = 0.337), and reduction and percent reduction in kidney volume (35.8 vs 36.4 cm(3), p = 0.886; 20.4% vs 24.0%, p = 0.151), respectively, were similar between the groups. On multivariate analysis renal volume reduction (%, p <0.0001) was the most significant, independent prognosticator for glomerular filtration rate reduction followed by polar location of the tumor (upper vs mid-lower pole, p = 0.012) and increasing age (p = 0.041). CONCLUSIONS: Renal volume reduction, tumor location and patient age determine renal function after partial nephrectomy. In appropriate cases the laparoscopic method can show surgical and functional outcomes equivalent to those of the open method.

Association of Prevalence of Benign Pathologic Findings After Partial Nephrectomy With Preoperative Imaging Patterns in the United States From 2007 to 2014.

Importance: Although the intent of nephron-sparing surgery is to eradicate malignant tumors found on preoperative imaging, benign masses often cannot be differentiated from malignant tumors. However, in the past there have been discrepancies in the reported percentages of benign masses removed by partial nephrectomy (PNx). Objective: To investigate the annual trend of prevalence of benign pathologic findings after PNx and to investigate what potential factors are associated with this prevalence. Design, Setting, and Participants: A total of 18 060 patients who underwent PNx between 2007 and 2014 were selected from Truven Health MarketScan Research Databases. We selected those patients who underwent PNx as an inpatient from 2007 and set the surgery date as the index date. Overall, a total of 21 445 patients with International Classification of Diseases, Ninth Revision, Clinical Modification code of 55.4 were identified from 2007 to 2015. Main Outcomes and Measures: The annual trend of benign pathologic findings was described as an actual number and as a proportion. Univariate and multiple analyses were performed to investigate factors predictive of a benign final pathologic diagnosis, including type of preoperative imaging modality or performance of a renal mass biopsy. Results: Among the 18 060 patients, mean (SD) age was 57 (12) years, and there were 10637 (58.9%) men and 7423 (41.1%) women. The overall prevalence of benign pathologic findings was 30.9% and the annual trends demonstrated a prevalence of over 30% for nearly every year of the study period. On univariate analysis, the performance of magnetic resonance imaging (MRI) and renal mass biopsy was associated with benign pathologic findings (P = .02 and P < .001, respectively). On multivariable analysis, female sex (odds ratio [OR], 0.62; 95% CI, 0.58-0.66; P < .001), older age (>65 years) (OR, 0.99; 95% CI, 0.99-0.99; P < .001), and computed tomography (CT) only preoperative imaging (OR, 1.16; 95% CI, 1.05-1.28; P = .004) were associated with benign pathologic findings after PNx. Conclusions and Relevance: We found that the overall prevalence of benign pathologic findings after PNx was higher than the literature suggests, with consistent year-over-year rates exceeding 30%. Female sex, older age (>65 years), and CT only preoperative imaging were predictive of a benign tumor. Further elucidation concerning covariates associated with a benign diagnosis should be the focus of future investigations to identify a cohort of patients who could potentially avoid unnecessary surgical intervention.

National trends of preoperative imaging modalities before partial nephrectomy for renal masses in the U.S. from 2007-2015.

INTRODUCTION: Although the performance of partial nephrectomies (PN) for renal masses has increased rapidly over the years, only a few studies have investigated the frequency and patterns of preoperative imaging modalities. The aim of this study was to investigate the frequency and patterns in preoperative imaging modalities before PN. METHODS: A total of 21 445 patients who underwent PN between 2007 and 2015 were selected from a national representative population in the MarketScan database and included in this study. The annual incidence and proportion of PN, as well as the use of each preoperative imaging modality were analyzed. RESULTS: Both annual crude number and frequency rate of PN decreased or became static since 2012. Computed tomography (CT) shows the greatest proportion of the crude number and percentage; despite a slight decrease in percentage, it is still >80%. Among the combinations, CT alone and CT combined with ultrasonography showed the highest performance rate during the complete observational period. The proportion of all other combinations, which include other complex combinations except CT alone, CT plus ultrasonography, CT plus magnetic resonance imaging (MRI), and CT plus MRI plus ultrasonography, was 13.95% in 2007, but increased to 19.04% in 2014. CONCLUSIONS: CT still plays a major role in preoperative imaging for renal masses, whereby CT alone and CT combined with ultrasonography account for a major proportion of the preoperative imaging patterns. The use of other imaging combinations, as well as renal biopsies, shows an increasing trend. Additional studies are needed to investigate whether this trend in preoperative imaging is related to the frequency rate of PN.

Evaluation of Performance Parameters of the Disposable Flexible Ureterorenoscope (LITHOVUE) in Patients with Renal Stones: A Prospective, Observational, Single-arm, Multicenter Study.

We investigated performance parameters of disposable flexible ureterorenoscopy (LITHOVUE) in patients with renal stones in a prospective, multicenter, observational study. Sixty two patients who underwent ureterorenoscopic surgery by LITHOVUE were included. Surgeons using a numerical scale, evaluated the maneuverability of the scopes and general perceptions of visibility related to the monitor and irrigation systems. General pain and fatigue scores were evaluated and compared to existing scopes. Mean patient age was 57.3 years and stone size was 15.4 mm. Clinical success of overall stone removal was 82.3%. Complications occurred in 4 cases of the Clavien classification grade I in a single case and II in 3 cases. Comparative parameters of maneuverability, perception of the monitor system and perception of the irrigation channel were 2.5, 2.5, and 3.0, respectively. The most favorable evaluation of physical strain was about 'shoulder fatigue' and 'hand fatigue'. Unfavorable evaluations were recorded for 'wrist stiffness' and 'thumb fatigue'. Maximal deflection angles of 270° were preserved in 53 cases (85.5%). No pre-stenting procedure and the longer operative time were significant predictors of poorly-preserved deflection angles <270°. LITHOVUE showed good maneuverability and perception scores for the monitor and irrigation systems. LITHOVUE received favorable evaluations on pain and fatigue scores.

Risk factors for acute kidney injury after percutaneous nephrolithotomy: Implications of intraoperative hypotension.

Percutaneous nephrolithotomy (PNL) is a minimally invasive technique for renal stone removal but can cause renal parenchymal injury. Renal stones can also affect renal function. We evaluated the risk factors for acute kidney injury (AKI) after PNL.The study cohort included 662 patients who underwent PNL. Patient characteristics, preoperative laboratory values, intraoperative data, and stone characteristics were collected. Univariate and multivariate logistic regression analyses were performed to identify risk factors for AKI after PNL. Postoperative outcomes such as hospitalization, intensive care unit admission rate and stay duration, and chronic kidney disease were also evaluated.Of the total study series, there were 107 (16.2%) cases of AKI after PNL (AKI group), and 555 (83.8%) patients who showed no injury (no-AKI group). The risk factors for AKI after PNL were found to be a higher preoperative serum uric acid level [odds ratio (OR) = 1.228; 95% confidence interval (95% CI) = 1.065-1.415; P = .005], longer operation time (OR = 1.009; 95% CI = 1.004-1.014; P < .001), and intraoperative hypotension (OR = 12.713; 95% CI = 7.762-20.823; P < .001). Hospitalization and intensive care unit stay duration were significantly longer in the AKI group (8.7 ±â€Š5.2 vs 6.6 ±â€Š2.8 days, P < .001; 0.34 ±â€Š1.74 vs 0.07 ±â€Š0.48 days, P = .002, respectively). Chronic kidney disease was also significantly higher in the AKI group (63.6% vs 32.7%, P = .024).As intraoperative hypotension is an important risk factor for AKI after PNL, which leads to poor postoperative outcomes, it should be prevented or managed vigorously during PNL.

In vitro, in vivo, and clinical tests of a novel flexible ureteroscope for the diagnosis and treatment of kidney and ureteral diseases.

Purpose: Despite advances in flexible ureteroscopy, the high cost and long repair time of ureteroscopes limit their use in the urology. We compared the performance of a novel flexible ureteroscope (fURS) 'HF-EH' with that of the two contemporary fURSs 'URF-P6' and 'COBRA'. Materials and Methods: We compared in vitro measurements of deflection angle, irrigation flow rate, and image quality between HF-EH and URF-P6 while also inspecting renal collecting systems in five female pigs. For clinical testing, we performed retrograde intrarenal surgeries using HF-EH in four patients. Experienced urologists compared performance parameters (irrigation, convenience, and maneuverability) between the HF-EH and COBRA. Results: The flow rate of HF-EH (21.0 mL/min) was worse, and its resolution (1.59 line pairs/mm) was inferior to that of URF-P6 (28.7 mL/min and 3.17 line pairs/mm, respectively). However, HF-EH was superior to URF-P6 in terms of loss of deflection angle with the insertion of accessories (1.8% vs. 12.7%). In vivo and clinical testing revealed that the performance parameters of HF-EH were slightly inferior to those of conventional domestic fURSs. We successfully performed retrograde intrarenal surgeries using HF-EH in four patients and achieved stone-free statuses in two. None of the patients exhibited any procedure-related complications. Conclusions: Although we observed that two of the three performance parameters of the novel ureteroscope 'HF-EH' were inferior to those of the conventional ureteroscope, we successfully used HF-EH to perform retrograde intrarenal surgeries in patients. Further studies on performance and durability are warranted for making HF-EH commercially available.

Metal Deposition on a Self-Generated Microfibril Network to Fabricate Stretchable Tactile Sensors Providing Analog Position Information.

Stretchable conductors and sensors have attracted great attention for use in electronic skin and healthcare monitoring. Despite the development of many stretchable conductors, there are still very few studies that utilize the conventional methods making electrodes and circuits used in current industry. A method is proposed to fabricate a stretchable electrode pattern and a stretchable tactile sensor by simply depositing linear metal lines through a mask on a stretchable substrate. A method is developed of a self-generating microfibril network on the surface of stretchable block copolymer substrates. The formation mechanism of the microfibril network is studied with finite element method simulations. Metals (Au and Ag nanowires) are deposited directly on the substrate through a patterned mask. This study shows that strain-insensitive circuit and strain-sensitive sensor can be fabricated in a controlled way by adjusting the thickness of the deposited metal, which makes it easy to fabricate a tactile sensor by metal deposition. Also, by using the characteristic that the sensor has different sensitivity depending on the line pattern width, a novel sensor structure simultaneously providing analog-type position information and pressure value is proposed.