Evaluation of renovated double J stents using ureter models with and without stenosis.

PURPOSE: Commercial double J stents (DJS) have a uniform shape regardless of the specific nature of various ureteral diseases. We tested renovated DJS and compared them with conventional DJS using ureter models. METHODS: One straight ureter model included stenosis at the distal ureter near the ureterovesical junction and the other did not. We used conventional DJS and renovated 5- and 6-Fr soft DJS for ureter stones and 6-, 7-, and 8.5-Fr hard DJS for tumors. The DJS comprised holes in the upper, middle, or lower one-third of the shaft (length, 24 cm; 2-cm-diameter coils at both ends). More holes were created along the shaft based on the ureteral disease location. Conventional DJS had holes spaced 1 cm apart along the shaft. Renovated DJS had holes spaced 1 cm apart along the shaft with 0.5-cm intervals on the upper, middle, or lower one-third of the shaft. Urine flow was evaluated. RESULTS: As the DJS diameter increased, the flow rate decreased. The flow rates of DJS with holes in the lower shaft were relatively lower than those of conventional DJS and DJS with holes in the upper and middle shafts. In the ureter model without stenosis, 6-, 7-, and 8.5-Fr renovated stents exhibited significantly higher flow rates than conventional stents. In the ureter model with stenosis, 5-, 6-, 7-, and 8.5-Fr renovated stents did not exhibit significantly higher flow rates than conventional stents. CONCLUSION: Renovated stents and conventional stents did not exhibit significant differences in urine flow with stenosis.

Evaluation of encrustation of double J stents with artificial urine.

PURPOSE: To evaluate the formation of encrustation on double J stents (DJSs) using artificial urine. MATERIALS AND METHODS: In this study, a static urinary system containing artificial urine was created, and a total of 45 DJSs were used to evaluate the formation of encrustation. Three groups of 15 DJSs were tested for 4, 8, or 14 weeks. The formation of encrustation on the DJSs over the weeks was analyzed using methods including X-ray powder diffraction (XRD), inductively coupled plasma spectrophotometer (ICP), and scanning electron microscope (SEM). Statistical analysis and the uncertainty test were used for data analysis using R language. RESULTS: The ICP analyzed the weight of the calcium and magnesium, which are the major components of urinary stones and encrustation, and showed that it was the heaviest at 14 weeks. Measurement of the area of encrustation on the outer surface of the DJSs revealed that the encrustation area at the bottom of the stent was greater than that at the top of the stent, regardless of the experimental period (proximal part: ≤ 41,099 µm2, distal part: ≤ 183,259 µm2). Encrustation occurred around the side holes of DJSs and became bigger over time to fill up the side holes. CONCLUSION: Encrustation spots included the bottom zone of the DJS and around the side holes. These results indicate that the performance of DJSs would be improved by modifying the shape of DJSs located near the bladder and side holes.

The ethanol extract of Aquilariae Lignum ameliorates hippocampal oxidative stress in a repeated restraint stress mouse model.

BACKGROUND: Chronic stress contributes to the development of brain disorders, such as neurodegenerative and psychiatric diseases. Oxidative damage is well known as a causative factor for pathogenic process in brain tissues. The aim of this study is to evaluate the neuroprotective effect of a 30% ethanol extract of Aquilariae Lignum (ALE) in repeated stress-induced hippocampal oxidative injury. METHODS: Fifty BALB/c male mice (12 weeks old) were randomly divided into five groups (n = 10). For 11 consecutive days, each group was orally administered with distilled water, ALE (20 or 80 mg/kg) or N-acetylcysteine (NAC; 100 mg/kg), and then all mice (except unstressed group) were subjected to restraint stress for 6 h. On the final day, brain tissues and sera were isolated, and stress hormones and hippocampal oxidative alterations were examined. We also treated lipopolysaccharide (LPS, 1 µg/mL)-stimulated BV2 microglial cells with ALE (1 and 5 µg/mL) or NAC (10 µM) to investigate the pharmacological mechanism. RESULTS: Restraint stress considerably increased the serum levels of corticosterone and adrenaline and the hippocampal levels of reactive oxygen species (ROS), nitric oxide (NO), and malondialdehyde (MDA). ALE administration significantly attenuated the above abnormalities. ALE also significantly normalized the stress-induced activation of astrocytes and microglial cells in the hippocampus as well as the elevation of pro-inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1ß). The in vitro assay outcome supplemented ALE could dramatically block NF-κB activation in microglia. The anti-oxidative stress effects of ALE were supported by the results of antioxidant components, 4-hydroxynonenal (4-HNE), NADPH oxidase 2 (NOX2), inducible nitric oxide synthase (iNOS) and NFE2L2 (Nrf2) in the hippocampal tissues. CONCLUSIONS: We firstly demonstrated the neuroprotective potentials of A. Lignum against hippocampal oxidative injury in repeated restraint stress. The corresponding mechanisms might involve modulations in the release of ROS, pro-inflammatory cytokines and stress hormones.

Low testosterone level is an independent risk factor for high-grade prostate cancer detection at biopsy.

OBJECTIVE: To investigate the relationship between low testosterone levels and prostate cancer detection risk in a biopsy population. PATIENTS AND METHODS: In all, 681 men who underwent initial 12-core transrectal prostate biopsy at our institution were included in this retrospective study. Patients were divided into groups with low (<300 ng/dL) and normal testosterone levels (≥300 ng/dL). Clinical and pathological data were analysed. RESULTS: Among 681 men, 86 men (12.6%) had low testosterone levels, 143 (32.7%) had a positive biopsy, and 99 (14.5%) had high-grade prostate cancer. The mean age, prostate-specific antigen (PSA) level, PSA density, body mass index (BMI), number of abnormal digital rectal examination (DRE) findings, and diabetes mellitus (DM) history were significantly different between the low and normal level testosterone groups. A low testosterone level was significantly associated with a higher risk of detection of overall prostate cancer than a normal testosterone level in univariate analysis (odds ratio [OR] 2.545, P = 0.001), but not in multivariate analysis adjusting for parameters such as age, PSA, prostate volume, BMI, abnormal DRE findings and DM (OR 1.583, P = 0.277). Meanwhile, a low testosterone level was significantly related to a higher rate of high-grade prostate cancer compared with a normal testosterone level in univariate (OR 3.324, P < 0.001) and multivariate analysis adjusting for other parameters (OR 2.138, P = 0.035). CONCLUSION: Low testosterone level is an independent risk factor for high-grade prostate cancer detection at biopsy. Therefore, checking testosterone levels could help to determine whether prostate biopsy should be carried out.

An Inductively-Powered Wireless Neural Recording System with a Charge Sampling Analog Front-End.

An inductively-powered wireless integrated neural recording system (WINeR-7) is presented for wireless and battery less neural recording from freely-behaving animal subjects inside a wirelessly-powered standard homecage. The WINeR-7 system employs a novel wide-swing dual slope charge sampling (DSCS) analog front-end (AFE) architecture, which performs amplification, filtering, sampling, and analog-to-time conversion (ATC) with minimal interference and small amount of power. The output of the DSCS-AFE produces a pseudo-digital pulse width modulated (PWM) signal. A circular shift register (CSR) time division multiplexes (TDM) the PWM pulses to create a TDM-PWM signal, which is fed into an on-chip 915 MHz transmitter (Tx). The AFE and Tx are supplied at 1.8 V and 4.2 V, respectively, by a power management block, which includes a high efficiency active rectifier and automatic resonance tuning (ART), operating at 13.56 MHz. The 8-ch system-on-a-chip (SoC) was fabricated in a 0.35-µm CMOS process, occupying 5.0 × 2.5 mm2 and consumed 51.4 mW. For each channel, the sampling rate is 21.48 kHz and the power consumption is 19.3 µW. In vivo experiments were conducted on freely behaving rats in an energized homecage by continuously delivering 51.4 mW to the WINeR-7 system in a closed-loop fashion and recording local field potentials (LFP).

A New Sliding-Loop Technique in Renorrhaphy for Partial Nephrectomy: A Feasibility Study in a Porcine Model.

BACKGROUND: We developed a sliding-loop technique that narrowed both sides of the parenchyma in a porcine model and compared it with the conventional sliding-clip technique. METHODS: Three pigs (30-40 kg) were reused following another experiment conducted by the same researchers. Bilateral kidneys were harvested within 30 minutes after euthanasia. Two partial nephrectomies per kidney were performed on opposite surfaces. All kidney defects were of the same size (diameter of 2.5-3 cm with a depth of 1.0-1.5 cm). The sliding-clip technique and sliding-loop technique were performed separately. In the sliding-loop technique, we created a 1-cm loop at the end of a Vicryl and placed a tetrafluoroethylene polymer pledget in front of the knots passing through the needle. The needle then crossed the loop after passing through the renal parenchyma. A Weck clip was placed and slid on one side to tighten the suture. Tightening was controlled with an equivalent force using a digital push-pull gauge. Three stitches were placed at each renorrhaphy site. The distance between repaired renal surfaces was measured at 5 different points (3 suture sites and 2 middle sites between sutures). RESULTS: The results of the 2 techniques were compared by using the independent t test. The mean distance between renal surfaces was significantly narrower in the sliding-loop technique than in the conventional technique (1.80 ± 1.08 mm vs 5.28 ± 2.46 mm, P < .001). CONCLUSION: In the porcine model, the sliding-loop technique more effectively closed the partial nephrectomy defects compared with the conventional sliding-clip technique.

Obesity and long-term survival after radical prostatectomy.

PURPOSE: Obesity is a modifiable risk factor associated with worse outcomes for many cancers, yet implications for prostate cancer are not well understood. Notably the impact of body mass index on long-term survival after treatment is unclear. We performed a retrospective cohort study on a large series of men who underwent radical prostatectomy to assess the impact of obesity on long-term biochemical recurrence-free survival, prostate cancer specific survival and overall survival. MATERIALS AND METHODS: Between 1982 and 2012, 11,152 men underwent radical prostatectomy at a single tertiary referral center. Patients were stratified according to body mass index as normal weight (body mass index less than 25 kg/m(2)), overweight (body mass index 25 to less than 30 kg/m(2)), mild obesity (body mass index 30 to less than 35 kg/m(2)) and moderate/severe obesity (body mass index 35 kg/m(2) or greater), comprising 27.6%, 56.0%, 14.1% and 2.3% of the cohort, respectively. Covariates included age, preoperative prostate specific antigen, surgery year, Gleason score, pathological stage, surgical margin and race. Predictors of biochemical recurrence-free survival, prostate cancer specific survival and overall survival were identified using Cox proportional hazard models. RESULTS: Median followup was 5 years (range 1 to 27). Actuarial 20-year biochemical recurrence-free survival for mild and moderate/severe obesity was 65% and 51%, respectively, compared to 76% for normal weight men (p ≤0.001). In a multivariate model obesity was a significant predictor of biochemical recurrence-free survival (mild HR 1.30, p = 0.002; moderate/severe HR 1.45, p = 0.028) and overall survival (mild HR 1.41, p = 0.003; moderate/severe HR 1.81, p = 0.033). However, only mild obesity was significantly associated with prostate cancer specific survival (HR 1.51, p = 0.040), whereas moderate/severe obesity was not (HR 1.58, p = 0.356). CONCLUSIONS: Obese men have higher rates of biochemical recurrence than normal weight patients during long-term followup. Obesity at the time of surgery independently predicts overall survival and biochemical recurrence-free survival but not prostate cancer specific survival.

Obesity is associated with higher risk of prostate cancer detection in a biopsy population in Korea.

OBJECTIVE: To evaluate the impact of obesity on prostate cancer detection, as measured by the body mass index (BMI) in a Korean biopsy population. PATIENTS AND METHODS: We retrospectively reviewed the records of 1213 men who underwent transrectal ultrasonography-guided prostate biopsy at our institution. Biopsy outcomes were analysed with respect to various variables, including patient age, prostate-specific antigen (PSA), prostate volume, digital rectal examination (DRE) findings and obesity, defined as BMI ≥25 kg/m(2) , an Asian BMI category. RESULTS: Among 1213 men, 408 (33.6%) were obese and 344 (28.4%) had a positive biopsy. Obese men were younger (65.5 vs 67.1 years, P = 0.003), had a larger prostate (49.2 vs 42.9 mL, P < 0.001) and were less likely to have any abnormality on DRE (8.1 vs 15.9% P < 0.001) than non-obese men. In the multivariate analysis, obesity was significantly associated with a higher risk of prostate cancer detection in men undergoing biopsy (odds ratio [OR] = 1.446, P = 0.024). In addition, obesity was significantly associated with a higher rate of biopsy-detected high grade (Gleason score ≥4 + 3) disease, and this association remained after multivariate adjustment (OR = 1.498, P = 0.039). CONCLUSIONS: Obese men were younger, had a larger prostate, and had less tendency to have an abnormality on DRE than non-obese men. Obesity was associated with a higher risk of prostate cancer detection as an independent factor, including high grade prostate cancer in a Korean biopsy population.

Impact of positive surgical margins and their locations after radical prostatectomy: comparison of biochemical recurrence according to risk stratification and surgical modality.

PURPOSE: We investigated the influence of positive surgical margins (PSMs) and their locations on biochemical recurrence (BCR) according to risk stratification and surgical modality. METHODS: A total of 1,874 post-radical-prostatectomy (RP) patients of pT2-T3a between 2000 and 2010 at three tertiary centers, and who did not receive neoadjuvant/adjuvant therapy, were included in this study. Patients were stratified according to BCR risk: low risk (PSA <10, pT2a-b, and pGS ≤6), intermediate risk (PSA 10-20 and/or pT2c and/or pGS 7), and high risk (PSA >20 or pT3a or pGS 8-10). The median follow-up was 43 months. RESULTS: PSMs were a significant predictor of BCR in both the intermediate- and high-risk-disease groups (P = .001, HR 2.1, 95 % CI 1.3-3.4; P < .001, HR 2.8, 95 % CI 2.0-4.1). Positive apical margin was a significant risk factor for BCR in high-risk disease (P = .003, HR 2.0, 95 % CI 1.2-3.3), but not in intermediate-risk disease (P = .06, HR 1.7, 95 % CI 0.9-3.1). Positive bladder neck margin was a significant risk factor for BCR in both intermediate- and high-risk disease (P < .001, HR 5.4, 95 % CI 2.1-13.8; P = .001, HR 4.5, 95 % CI 1.8-11.4). In subgroup analyses, robotic RP provided comparable BCR-free survival regardless of risk stratification. Patients with PSMs showed similar BCR-free survival between open and robotic RP (log-rank, P = .897). CONCLUSIONS: Post-RP PSMs were a significantly independent predictor of disease progression in high-risk disease as well as intermediate-risk disease. Both positive apical and bladder neck margins are also significant risk factors of BCR in high-risk disease. Patients with PSMs showed similar BCR-free survival between open and robotic surgery.

Target genes involved in antiproliferative effect of modified ginseng extracts in lung cancer A549 cells.

Lung cancer is the most common cancer and the leading cause of cancer-related deaths. Panax ginseng has long been used to treat cancer and other diseases worldwide. Most of the pharmacological actions of ginseng are attributed to a variety of ginsenosides, which are often metabolized by intestinal bacteria into more effective forms. In this study, we found that the antiproliferative activity of ginseng was increased after enzymatic processing of ginseng saponin (50% inhibitory concentration, >70 µg/ml). To elucidate the mechanism by which modified ginseng extract (MGX) induced cell death in human lung cancer cells, the gene expression profiles of A549 cells regulated by MGX were assayed using Agilent PrimeView Human Gene Expression Arrays. The expression of 17 genes involved in the regulation of cell signaling, cell metabolism, transport, and cytoskeleton-regulation was up-regulated, whereas the expression of 16 genes implicated in invasion and metastasis and cellular metabolism was down-regulated in MGX-treated A549 cells. Moreover, nuclear staining with 4',6-diamidino-2-phenylindole revealed that MGX clearly caused nuclear condensation and fragmentation which are observed in apoptosis cell. These results elucidate crucial anticancer mechanisms of MGX and provide potential new targets for the assessment of anticancer activity of MGX.

Predictors of positive surgical margins and their location in Korean men undergoing radical prostatectomy.

OBJECTIVE: To evaluate preoperative predictors of positive surgical margins and their location in Korean men undergoing radical prostatectomy. METHODS: A total of 3227 patients who had undergone radical prostatectomy (open, robotic or laparoscopic) for clinically localized prostate cancer at three centers between 2000 and 2010 were analyzed. Patients were stratified by using the D'Amico risk criteria. Positive surgical margins were categorized according to their location. Patients were divided depending on their prostate volume: <29, 29-36, 36-46 and ≥46 mL. All of the patients had a minimum of six. A total of 2041 patients (84.9%) underwent 12-14 core biopsies. In each patient, the number and location of positive cores with cancer were assessed. In the analysis of predictive factors for positive surgical margin locations, regression analysis was carried out using only open and robotic prostatectomy. RESULTS: The preoperative prostate-specific antigen, prostate volume, biopsy Gleason scores and clinical stage were significantly associated with an increased risk of positive surgical margins. The predictive variables for positive apical margin were small prostate volume (less than 29 mL) and positive apical biopsy. There were no statistically significant predictors for positive posterolateral or basal margin. Positive apical biopsy was the predictor of positive apical margin in open (odds ratio 1.7, P = 0.009) and robotic prostatectomy (odds ratio 2.2, P = 0.041). Small prostate volume was the predictor of positive apical margin in open prostatectomy (odds ratio 1.6, P = 0.012), but for positive basal margin in robotic radical prostatectomy (odds ratio 4.5, P < 0.001). In survival analysis, positive basal margin showed worse prognoses on biochemical recurrence than positive apical margin. CONCLUSIONS: High prostate-specific antigen and small prostate volume are predictive factors of positive surgical margin in Korean patients undergoing radical prostatectomy. Apical positivity on extended transrectal biopsy represents a predictive factor of positive surgical margin. Small prostate volume is associated with higher risk of positive surgical margins at the apex in open radical prostatectomy and at the base in robotic-assisted laparoscopic radical prostatectomy.

Optimal thrombin injection method for the treatment of femoral artery pseudoaneurysm.

BACKGROUND: Iatrogenic femoral artery pseudoaneurysm (IFP) incidence is increasing with increase in diagnostic and therapeutic angiography, and so, the less invasive percutaneous thrombin injection (PTI) is the most widely used treatment. Moreover, studies that minimize PTI complications and highlight therapeutic effects are lacking. OBJECTIVES: This study performed in vitro thrombosis modeling of pseudoaneurysms and analyzed thrombosis within and thromboembolism outside the sac during thrombin injection. METHODS: We evaluated PTI in terms of thrombin injection location (at the junction of the IFP sac and neck, the center, and the dome, located farthest from the neck of the sac), thrombin injection time (5 and 8 seconds), and blood flow rate (ranging from 210 mL/min to 300 mL/min). Porcine blood was used as the working fluid in this study. RESULTS: Thrombin injection at the junction of the IFP sac and the pseudoaneurysm neck led to less thrombosis within the sac but substantial thrombi consistently outside the sac, whereas thrombin injected at the sac center mostly led to complete thrombosis within the sac, preventing further blood flow into the sac and reducing likelihood of thrombi outside the sac. A longer thrombin injection time enhanced the therapeutic effect and decreased the possibility of thromboembolism. Thromboembolism occurred more frequently at flow rates of >240 mL/min. CONCLUSION: The thrombin injection site in a pseudoaneurysm significantly influences thrombogenesis within and thromboembolism outside the sac. Thus, slow and deliberate injection of thrombin into the center of the sac could potentially reduce complications and enhance treatment efficacy.

Pure transvesical NOTES appendectomy using a 5-mm rigid laparoscope: a feasibility and survival study with porcine models.

BACKGROUND: Previously, the authors demonstrated the feasibility of a pure transvesical natural orifice translumenal endoscopic surgery (NOTES) for uterine horn resection (UHR) using a rigid ureteroscope in swine as an appendectomy model. However, visualization was poor, and there was room for improvement. The authors have assessed the feasibility and safety of a revised technique that uses a 5-mm rigid laparoscope. METHODS: Eight operations on four female pigs (35-40 kg) were performed as a proof of concept study. Four right-side operations were performed in a survival model. The surgical procedure was similar to the original technique. However, the rigid ureteroscope was replaced by a 5-mm laparoscope after modification of the access system. In addition, the clipped metal threads used for bladder closure were easily placed with a long 13-gauge needle. In the survival model, a Foley catheter was placed for 1 day. RESULTS: The new technique provided considerably better visualization and operability than the original technique. The mean total operative time was 96.6 ± 18.2 min, and the mean estimated blood loss was 15.0 ± 13.5 ml. On postoperative day 3, pig 2 in the survival study died of peritonitis resulting from a small bowel injury. The lab results for the other pigs demonstrated no adverse events and tolerable immune responses. Necropsy showed complete healing of the vesicotomy. CONCLUSIONS: The revised transvesical NOTES UHR technique improved the outcomes and feasibility of the original technique. This approach may be translatable to human appendectomy procedures in the future.

Effects of size and shape of the side holes of a double J stent on the ureter fluid flow after stenosis.

The effect of side holes morphology changes in double J stent (DJS) on encrustation was analyzed using computational fluid dynamics (CFD). We analyzed DJS side holes with inner diameter of 1 mm and outer diameters of 1 (type A), 1.2 (type B) and 1.4 (type C) mm, respectively. Concentric stenosis with three intraureteral degree (0%, 12%, and 88%) was analyzed. The flow rate, shear stress and wall shear stress (WSS) distribution were investigated. Urine flow through SH1 before the ureteropelvic junction (UPJ) differed based on the ureteral stenosis degree. The sum of flow rates through the SHs increased with diameter. In the stented ureter with 12% stenosis, the flow rate through SH1 approximately doubled than that without ureteral stenosis, and the flow rate through SH1 was maximal for the type 'C' stent in both 12% and 88% ureteral stenosis. The mean shear stress in the SHs increased with the degree of stenosis. The WSS around the SHs was higher for type 'C' than types A and B. From the flow rates and shear stresses in and around the SHs, the larger SH diameter of the DJS from the UPJ to mid-ureter is expected to induce encrustation reduction, especially in patients with urinary lithiasis.

Patients aged more than 70 had higher risk of locally advanced prostate cancers and biochemical recurrence in Korea.

UNLABELLED: Study Type - Prognosis (cohort series) Level of Evidence 2b. What's known on the subject? and What does the study add? This study reports that patients aged 70 years or older have a higher possibility of locally advanced cancer than younger patients. Instead of conservative management, radical eradication of clinically localized prostate cancer should be actively considered in well-selected healthy patients older than 70 years. OBJECTIVE: • To analyse the differences in the clinicopathological results between two groups of Korean patients aged younger or older than 70 years with clinically localized prostate cancer. METHODS: • A cohort of consecutive male patients who underwent radical prostatectomy was retrospectively analysed. In total, 995 patients (74.6%) were younger than 70 years, and 338 patients (25.4%) were 70 years or older. • Biochemical recurrence (BCR) -free survival was evaluated in the patients, who were followed up for more than 24 months. • The Kaplan-Meier method was used to calculate survival estimates for BCR-free survival. Multivariate Cox proportional hazard regression analysis was performed to predict non-organ-confined status and BCR. RESULTS: • Mean preoperative prostate-specific antigen (PSA) levels and biopsy or pathological Gleason scores showed no differences between the two age groups. • Older patients, aged more than 70 years, displayed significantly higher risk of locally advanced prostate cancer and BCR than younger patients. • Subgroup analysis showed that the risk of the presence of locally advanced disease was significantly increased in patients of 70 years or older when we compared the proportion of locally advanced disease only in patients with PSA <4 ng/mL. • Multivariate analysis showed that old age, high PSA and high Gleason score were significantly associated with non-organ confined status and BCR. CONCLUSIONS: • Patients aged 70 years or older had a higher possibility of locally advanced cancer than younger patients. • Radical eradication of clinically localized prostate cancer should be actively considered in well-selected healthy patients older than 70 years.

Pure transvesical NOTES uterine horn resection in swine as an appendectomy model.

BACKGROUND: Because of size limitation, the lack of reliable instruments, and bladder closure methods, transvesical natural orifice translumenal endoscopic surgery (NOTES) is still in its infancy. The porcine uterine horn is similar to the human vermiform appendix. Therefore, the resection of the porcine uterine horn is an established animal model for the human appendectomy. In this study, we evaluated the feasibility of a pure transvesical NOTES approach to uterine horn resection in a porcine model. METHODS: We performed five operations on three female pigs (30-35 kg) under general anesthesia in the Trendelenburg position. The laparoscope at the umbilicus was used only for the purpose of documentation. We used a rigid ureteroscope and a customized access system that prevented gas leakage and facilitated in-and-out passage of the instruments. A vesicostomy was created on the posterolateral bladder wall by using a needle knife through the channel of the ureteroscope. The uterine horn resection was performed by using an electric needle knife, hot forceps, and a polypectomy snare through the access system placed in vesicostomy. Bladder closure was performed with extracorporeal ties using metal clip tagged threads and a knot-pusher. RESULTS: We successfully performed the pure transvesical NOTES uterine horn resections. The mean total operative time was 141.8 (± 58.7) min, and blood loss was minimal in all cases. No leakage was observed at the bladder repair sites after filling with normal saline. The removed uterine horns were approximately 6-12-cm long and 0.6-0.8 cm in diameter. On final inspection, the urethras were not damaged. CONCLUSIONS: This study demonstrates the feasibility of a pure transvesical NOTES uterine horn resection in a porcine model. To the best of our knowledge, this is the world's first report on a pure transvesical NOTES with a therapeutic purpose. This study shows the potential for adoption of the transvesical approach in NOTES procedures.

Nomograms to predict the pathological stage of clinically localized prostate cancer in Korean men: comparison with western predictive tools using decision curve analysis.

OBJECTIVES: To develop and evaluate nomograms to predict the pathological stage of clinically localized prostate cancer after radical prostatectomy in Korean men. METHODS: We reviewed the medical records of 2041 patients who had clinical stages T1c-T3a prostate cancer and were treated solely with radical prostatectomy at two hospitals. Logistic regressions were carried out to predict organ-confined disease, extraprostatic extension, seminal vesicle invasion, and lymph node metastasis using preoperative variables and resulting nomograms. Internal validations were assessed using the area under the receiver operating characteristic curve and calibration plot, and then external validations were carried out on 129 patients from another hospital. Head-to-head comparisons with 2007 Partin tables and Cancer of the Prostate Risk Assessment score were carried out using the area under the curve and decision curve analysis. RESULTS: The significant predictors for organ-confined disease and extraprostatic extension were clinical stage, prostate-specific antigen, Gleason score and a percent positive core of biopsy. Significant predictors for seminal vesicle invasion were prostate-specific antigen, Gleason score and percent positive core, and those for lymph node metastasis were prostate-specific antigen and percent positive core. The area under the curve of established nomograms for organ-confined disease, extraprostatic extension, seminal vesicle invasion and lymph node metastasis were 0.809, 0.804, 0.889 and 0.838, respectively. The nomograms were well calibrated and externally validated. These nomograms showed significantly higher accuracies and net benefits than two Western tools in Korean men. CONCLUSION: This is the first study to have developed and fully validated nomograms to predict the pathological stage of prostate cancer in an Asian population. These nomograms might be more accurate and useful for Korean men than other predictive models developed using Western populations.

Temporal changes of PIRADS scoring by radiologists and correlation to radical prostatectomy pathological outcomes.

Purpose: To assess temporal improvement of prostate image reporting and data system (PIRADS) 3-5 lesion correlation to histopathologic findings from radical prostatectomy (RP) in prostate cancer (PCa). Materials and methods: A total of 1481 patients who underwent RP for biopsy-proven PCa between 2015 and 2019 were divided into 14 groups of 100 sequential readings for the evaluation of histopathological correlation with PIRADS readings. Temporal trends of PIRADS distribution and predictive performance for RP pathology were evaluated to assess underlying changes in prostate magnetic resonance imaging (MRI) interpretation by radiologists. Results: PIRADS 4-5 lesions were significantly correlated with the increasing rates of Gleason Group (GG) upgrade (p = 0.044) and decreasing rate of GG downgrade (p = 0.016) over time. PIRADS ≥3 lesions read after median 2 years of experience were shown to independently predict intermediate-high-risk (GG ≥ 3) PCa (odds ratio 2.93, 95% confidence interval 1.00-8.54; P= 0.049) in RP pathology. Preoperative GG ≥ 3 biopsy lesions with PIRADS 4-5 lesions were significantly more susceptible to GG upgrade (P= 0.035) and GG ≥ 4 RP pathology (p = 0.003) in experienced reads, in contrast to insignificant findings in early readings (p = 0.588 and 0.248, respectively). Conclusion: Preoperative MRI reports matched with RP pathology suggest an improved prediction of adverse pathology in PIRADS 3-5 lesions over time, suggesting a temporal change in PIRADS interpretation and predictive accuracy. Institutions with low volume experience should use caution in solely relying on MRI for predicting tumor characteristics. Future prospective trials and larger scale assessments are required to further validate our results.

CFD study on vesicoureteral reflux in the urinary tract with double J stent.

OBJECTIVE: This study investigates the effects of vesicoureteral reflux (VUR) in the upper and lower urinary tracts with and without ureteral stenosis and with a double J stent (DJS). METHODS: The entire length of the urinary tract with an implanted DJS was modeled. To assess the possibility of VUR, the measured values were used as boundary conditions for the baseline, the maximum cystometric bladder capacity (MCBC) during the filling phase, and maximum vesical pressure during the voiding phase were computed. The flow rates, flow patterns, wall shear stress (WSS) distribution, impact force induced by reflux urination, and helicity of the bladder were investigated for the urinary system. RESULTS: The flow from the bladder to the renal pelvis was detected at maximum vesical pressure (75 cmH2O) during the voiding phase, and a small amount (1.09 mL/s) of VUR was noted at the MCBC during the filling phase. The WSS increased when the reflux was large. Helicity within the bladder varied with the stenosis as well as opening and closing of the urethra. The reflux within the stent was reduced by 40% by inserting a ball into the stent. CONCLUSION: The main VUR factor was the opening and closing of the vesicoureteric junction by the detrusor muscle. The largest urine reflux (11.7 mL/s) to the kidney occurred when the detrusor muscle was relaxed. SIGNIFICANCE: Ureteral stenosis affected the VUR and reduced urine reflux. Ball insertion in the stent reduced urine reflux through the stent lumen.

Urine flow analysis using double J stents of various sizes in in vitro ureter models.

A double J stent (DJS) is used to alleviate the congestion of urine in the upper urinary tract when there is ureteral stenosis, which causes the interruption of normal urine flow and results in renal failure. The purpose of placing DJSs is to ensure sufficient urine flow in the ureter, but the DJS acts as a foreign body in the urinary system and sometimes acts as an obstacle in achieving sufficient urine flow. Here, to evaluate the performance of various sizes of DJSs, 5Fr (1.666 mm) to 8Fr (2.666 mm), in the ureter, silicon ureter models without stenosis, and a circulation setup were constructed. The total flow rates (TFRs) in the stented ureters were evaluated with an in vitro experiment. The TFRs in the 5Fr DJS were larger than those in the other sizes of DJS. As the size of DJS increased, the TFR decreased. Computational fluid dynamics was also applied to validate the experimental results. It was shown that the experimental results agreed well with the numerical results.