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Introduction and objectives: Percutaneous nephrolithotomy remains a challenging procedure primarily due to difficulties obtaining access. Indeed, few urologists obtain their own access due to difficulties using a fluoroscopic or ultrasonic based antegrade puncture technique. Herein we report the first experience using holmium laser energy to obtain access in a retrograde fashion.Methods: After a pretreatment week of tamsulosin 0.4 mg/day (one center only) and following a documented sterile urine, a total of ten patients underwent retrograde holmium laser-assisted endoscopic-guided nephrostomy access in a prone split leg position.Results: In nine of ten patients, ureteroscopic guided, holmium laser access via an upper pole posterior calyx was achieved. In one patient, the laser tract could not be safely dilated and antegrade endoscopic and fluoroscopic guided access was performed. The mean operative time was 202 min; the mean fluoroscopy time was 32 s (6/9 cases). The mean pre-operative stone volume was 14,420 mm3. CT imaging on post-operative day 1 revealed 6/6 patients had residual stone fragments with total mean volume of 250 mm3 (96% reduction); there were no residual fragments in three patients who were evaluated with non-CT radiographic imaging (KUB). There was a single complication requiring angioembolization due to a subcapsular hematoma with associated secondary tearing of an inter-polar vessel remote from the nephrostomy site.Conclusions: Holmium laser-assisted endoscopic-guided retrograde access in a prone split-leg position was successfully performed at two institutions. The accuracy of nephrostomy placement and lessening of fluoroscopy time are two potential benefits of this approach. [ABSTRACT FROM AUTHOR]

Objectives: To report the treatment outcomes of patients with extrinsic ureteral obstruction treated with metallic stents and to identify the factors predicting stent failure. Methods: A total of 52 patients with extrinsic ureteral obstruction as a result of malignancy (66 ureters) were treated with metallic stents (Resonance®) and included in the study. The median observation period was 118 days. Results: The median survival time of these patients was 210 days, and the stent patency rate was 86.0% at 6 months and 60.0% at 1 year. Eight (15.4%) patients underwent nephrostomy as a result of stent failure. The occlusion rate of bilateral ureteral obstructed cases was significantly higher than that of unilateral cases. There was no correlation between the preoperative serum creatinine level, causes of ureteral occlusions (compression by tumor, lymph node metastasis, peritoneal dissemination), obstructed site (upper, middle, lower ureter) and stent failure. Conclusions: Metallic stents are excellent in maintaining patency compared with the conventional stents. Therefore, they can be used as first‐line treatment of malignant ureteral obstructions. [ABSTRACT FROM AUTHOR]

Modern-day percutaneous nephrolithotomy (PNL) has undergone considerable evolution, mainly driven by the improvement in access techniques, endoscopic instrumentation technology, lithotripsy devices and drainage management. The introduction of the supine and supine-modified positions is also part of this evolution, enabling comfortable and safe procedures from an anaesthesiological point of view, and an easy combined retrograde surgery [Endoscopic Combined IntraRenal Surgery (ECIRS)], allowing tailoring of the procedure on the patient, the dynamic anatomy of the collecting system and the urolithiasis. The conceptual value of ECIRS extends beyond the single diagnostic and active advantages due to the simultaneous contribution of the flexible retrograde ureteroscopy: the merit consists in the promotion of the versatile attitude of the urologist, and in the fulfillment of a personalized stone management. ECIRS has no pretensions of superiority, but for sure is a new safe and effective way of interpreting PNL, in the hands of an experienced surgical team. [ABSTRACT FROM AUTHOR]

Dysregulation of microRNAs in various types of human cancer promote or suppress oncogenesis. MicroRNA (miR)-1 was previously revealed to function as a tumor suppressor in prostate cancer cells, and its expression was associated with reduced metastatic potential in lung cancer. The present study investigated the role of miR-1 and its association with phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit α (PIK3CA) in the pathophysiology of esophageal squamous cell carcinoma (ESCC), and analyzed the effects of miR-1 inhibitor or mimics on sensitivity to epidermal growth factor receptor-tyrosine kinase inhibitors, the alterations of cell cycle distribution and apoptosis in ESCC cells. Compared with normal tissues, the level of miR-1 expression was significantly lower and PIK3CA expression was higher in ESCC tissues. The level of miR-1 expression was also inversely associated with the level of PIK3CA mRNA expression. Low miR-1 and high PIK3CA expression levels were strongly associated with lymph node metastasis, and the level of miR-1 expression was negatively associated with clinical Tumor-Node-Metastasis stage. Furthermore, exogenous expression of miR-1 inhibited growth, arrested cell cycle in the G1 phase and increased apoptosis in ESCC cells, whereas it decreased PIK3CA protein expression levels. Furthermore, overexpression of miR-1 increased the sensitivity of ESCC cells to the anticancer drug, gefitinib. A possible mechanism for this increased sensitivity to gefitinib may be inactivation of the PIK3CA signaling pathway. To the best of our knowledge, this is the first time that the results of the present study demonstrated that miR-1 upregulation may be a potential strategy for the treatment of human ESCC. [ABSTRACT FROM AUTHOR]

Aim: To evaluate the effects of prostatic apex shape variations on positive apical margin (PAM) rate after radical prostatectomy (RP) by undertaking a comparative study of robot-assisted laparoscopic radical prostatectomy (RALP) vs open radical prostatectomy (ORP). Patients and Methods: A total of 3324 cases of RP (1004 ORP and 2320 RALP) from January 2004 to March 2017 were retrospectively reviewed. All patients underwent preoperative MRI and the cohorts were stratified into four categories according to prostatic apical shape at the midsagittal plane. Between ORP and RALP groups, age, body mass index, preoperative prostate-specific antigen (PSA), biopsy and pathological Gleason score (GS), clinical and pathological stage, and prostatic apex shapes were compared. Logistic regression analyses were performed to evaluate significant predictors of PAM. Propensity adjustments were undertaken before statistical analysis to minimize the lack of randomization. Results: ORP and RALP groups showed no significant differences in age, body mass index, PSA, biopsy and pathological GS, clinical and pathological stage, as well as prostatic apical shape variations. The ORP group showed a PAM of 17.5% that was significantly higher than 12.3% of the RALP group ( p < 0.001). Both groups showed the highest PAM with apical type 3, which is the apex covering the posterior aspect of membranous urethra (ORP 33.9%, RALP 28.5%). In unadjusted data, multiple logistic regression analysis showed that prostate apical type 3 was a significant independent predictor of PAM, but other apex types were not. Conclusions: Prostate apical type 3 was a significant independent predictor of PAM. The RALP group showed better outcomes in terms of PAM compared with the ORP group. Preoperative MRI might be a potentially useful tool for preoperative designing of the surgical modalities. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to evaluate the efficacy and safety of a new articulating bipolar energy device, the EndoWrist® One™ Vessel Sealer (VS), in da Vinci® robot-assisted gastrectomy.Materials and Methods: Patients (n = 17) with cT1/2 gastric cancer who underwent robotic gastrectomy using the VS were prospectively enrolled in the study group (VS group). The clinicopathological outcomes, including operative time, intraoperative blood loss, amount of postoperative drainage, postoperative biochemical analysis results, and complication rates, were prospectively collected and compared with those of patients who underwent robotic gastrectomy using conventional ultrasonic shear force ([US] group, n = 52) during the same time period.Results: Although the VS provided a good direction for dissection because of the articulating function, the ancillary use of conventional bipolar coagulation was occasionally needed due to the blunt, nonactive end tip of the VS. The operative time, intraoperative blood loss, postoperative drainage, and absence of complication rates did not differ between the VS and US groups, but the C-reactive protein levels on the second postoperative day (8.06 versus 11.7, P = .002) and serum albumin levels on the fifth postoperative day (3.51 versus 3.32, P = .019) were superior in the VS group.Conclusion: Use of the VS in robotic gastrectomy was feasible and provided good configuration in the direction of dissection. The learning process for use of the VS in the initial series was relatively rapid, resulting in comparable results between the VS and US groups. Reduced inflammation and albumin loss were identified as possible benefits of the VS. [ABSTRACT FROM AUTHOR]

Background: The present study sought to explore the role of microRNA-330 (miR-330) in predicting the radiation response and prognosis of patients with brain metastasis (BM) from lung cancer (LC). Methods: Patients with BM from LC were identified and classified into radiation-sensitive and radiation-resistant groups according to the overall survival rate, local and distant recurrence rate after conventional whole-brain radiation therapy. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect miR-330 expression in serum. Receiver operating characteristic (ROC) curves were used to evaluate the prognostic value of miR-330 for the radiation sensitivity of brain metastasis from LC. Related clinical factors for radiation sensitivity were assessed by logistic regression analysis, and a survival analysis was conducted using COX regression and the Kaplan-Meier method. Results: MiR-330 exhibited lower expression in the radiation-sensitive group than in the radiation-resistant group. The area under the ROC curve of miR-330 for predicting radiation sensitivity was 0.898 (optimal cut-off value, 0.815), with a sensitivity of 71.7% and a specificity of 90.1%. After radiation therapy, patients with low miR-330 expression, compared to patients with high miR-330 expression, displayed a lower survival rate and a median survival time. MiR-330 expression was correlated with extracranial metastasis, maximum BM diameter, tumor-node-metastasis (TNM) stage and node (N) stage. Logistic regression and COX regression analyses revealed that extracranial metastasis, TNM stage, N stage and miR-330 expression were factors that influenced both radiation sensitivity and individual prognostic factors in patients with BM from LC. Conclusions: These findings indicate that the downregulation of miR-330 correlates with radiation sensitivity and poor prognosis in patients with BM from LC. [ABSTRACT FROM AUTHOR]

Background: Ultrasonography is a first-line imaging in the investigation of women's irregular bleeding and other gynaecological pathologies, e.g. ovarian cysts and early pregnancy problems. However, teaching ultrasound, especially transvaginal scanning, remains a challenge for health professionals. New technology such as simulation may potentially facilitate and expedite the process of learning ultrasound. Simulation may prove to be realistic, very close to real patient scanning experience for the sonographer and objectively able to assist the development of basic skills such as image manipulation, hand-eye coordination and examination technique. Objective: The aim of this study was to determine the face and content validity of a virtual reality simulator (ScanTrainer®, MedaPhor plc, Cardiff, Wales, UK) as reflective of real transvaginal ultrasound (TVUS) scanning. Method: A questionnaire with 14 simulator-related statements was distributed to a number of participants with differing levels of sonography experience in order to determine the level of agreement between the use of the simulator in training and real practice. Results: There were 36 participants: novices ( n = 25) and experts ( n = 11) who rated the simulator. Median scores of face validity statements between experts and non-experts using a 10-point visual analogue scale (VAS) ratings ranged between 7.5 and 9.0 ( p > 0.05) indicated a high level of agreement. Experts' median scores of content validity statements ranged from 8.4 to 9.0. Conclusions: The findings confirm that the simulator has the feel and look of real-time scanning with high face validity. Similarly, its tutorial structures and learning steps confirm the content validity. [ABSTRACT FROM AUTHOR]

Purpose: To assess the effectiveness and safety of robot-assisted radical prostatectomy (RARP) versus laparoscopic radical prostatectomy (LRP) in the treatment of prostate cancer. Materials and Methods: Existing systematic reviews were updated to investigate the effectiveness and safety of RARP. Electronic databases, including Ovid MEDLINE, Ovid Embase, the Cochrane Library, KoreaMed, Kmbase, and others, were searched through July 2014. The quality of the selected systematic reviews was assessed by using the revised assessment of multiple systematic reviews (R-Amstar) and the Cochrane Risk of Bias tool. Meta-analysis was performed by using Revman 5.2 (Cochrane Community) and Comprehensive Meta-Analysis 2.0 (CMA; Biostat). Cochrane Q and I2 statistics were used to assess heterogeneity. Results: Two systematic reviews and 16 additional studies were selected from a search performed of existing systematic reviews. These included 2 randomized controlled clinical trials and 28 nonrandomized comparative studies. The risk of complications, such as injury to organs by the Clavien-Dindo classification, was lower with RARP than with LRP (relative risk [RR], 0.44; 95% confidence interval [CI], 1.23-0.85; p=0.01). The risk of urinary incontinence was lower (RR, 0.43; 95% CI, 0.31-0.60; p<0.000001) and the potency rate was significantly higher with RARP than with LRP (RR, 1.38; 95% CI, 1.11-1.70; I²=78%; p=0.003). Regarding positive surgical margins, no significant difference in risk between the 2 groups was observed; however, the biochemical recurrence rate was lower after RARP than after LRP (RR, 0.59; 95% CI, 0.48-0.73; I²=21%; p<0.00001). Conclusions: RARP appears to be a safe and effective technique compared with LRP with a lower complication rate, better potency, a higher continence rate, and a decreased rate of biochemical recurrence. [ABSTRACT FROM AUTHOR]

Introduction: We evaluated a new digital single-use flexible ureteroscope, LithoVue™ with respect to deflection, image quality and maneuverability. Methods: A prospective cohort study was conducted in eight tertiary reference centers in Europe in December 2015 and January 2016. All consecutive patients included underwent flexible ureteroscopy and were 18 years or older. Deflection and image quality pre- and post-use and maneuverability were rated with a Likert scale. Results: A total of 40 procedures were performed (five per institution). The indication for FURS was treatment of renal stones in 92.5 % of the cases. Before LithoVue™ usage, the median measured upward and downward deflections were both 270°. Image quality was rated as 'very good' in 65 % of cases and 'good' in 30 %. Maneuverability was 'very good' in 77.5 % and 'good' in 17.5 %. At the final evaluation, median upward and downward deflections were both 270°. Image quality was still 'very good' in 65 % of cases and 'good' in 30 % with no significant difference compared with preoperative data ( p = 1). Maneuverability was 'very good' in 72.5 % and 'good' in 17.5 %, with no significant difference compared with preoperative data ( p = 0.92). Two LithoVue™ broke during surgery (5 %): one occurring in extreme deflection with acute infundibulopelvic angle and spontaneous loss of vision for the second one. Conclusion: The LithoVue™ displayed good image quality, active deflection and maneuverability. Further evaluation of surgical outcomes and cost analysis will help to present the best utility of this single-use FURS in current practice. [ABSTRACT FROM AUTHOR]

Prostate cancer is the most common malignancy among men in the US. Though considerable improvement in the diagnosis of prostate cancer has been achieved in the past decade, predicting disease outcome remains a major clinical challenge. Recent expression profiling studies in prostate cancer suggest microRNAs (miRNAs) may serve as potential biomarkers for prostate cancer risk and disease progression. miRNAs comprise a large family of about 22-nucleotide-long non-protein coding RNAs, regulate gene expression post-transcriptionally and participate in the regulation of numerous cellular processes. In this review, we discuss the current status of miRNA in studies evaluating the disease progression of prostate cancer. The discussion highlights key findings from previous studies, which reported the role of miRNAs in risk and progression of prostate cancer, providing an understanding of the influence of miRNA on prostate cancer. Our review indicates that somewhat consistent results exist between these studies and reports on several prostate cancer related miRNAs. Present promising candidates are miR-1, -21, 106b, 141, -145, -205, -221, and -375, which are the most frequently studied and seem to be the most promising for diagnosis and prognosis for prostate cancer. Nevertheless, the findings from previous studies suggest miRNAs may play an important role in the risk and progression of prostate cancer as promising biomarkers. [ABSTRACT FROM AUTHOR]

The chromism observed in the MEH-PPV polymer in tetrahydrofuran (THF) solution is discussed as a function of the structural morphology of the backbone chains. To evaluate this phenomenon, we carried out simulations employing a hybrid methodology using molecular dynamics and quantum mechanical approaches. Our results support the hypothesis that the morphological order-disorder transition is related to the change from red to blue phase observed experimentally. The morphological disorder is associated with total or partial twisted arrangements in the polymer backbone, which induces an electronic conjugation length more confined to shorter segments. In addition, the main band of the MEH-PPV UV-Vis spectrum at the lower wavelength is related to the blue phase, in contrast to the red phase found for the more planar backbone chains. [ABSTRACT FROM AUTHOR]

Purpose: To determine the incidence and predictors of major complications in patients undergoing percutaneous cryoablation (PCA) for small renal masses. Methods: We performed a retrospective analysis of patients undergoing PCA from 2005 to 2012. We analyzed demographic, radiographic, and complication data. We defined complications as any deviation from the expected postoperative course. We determined predictors of complications. Results: A total of 190 patients were included in the study. The mean age was 69 years, and 132 (69%) were males. The mean tumor diameter was 2.2 cm (0.8-4.0 cm). The mean number of probes utilized per procedure was 2.3. We observed 16 (8.4%) complications including 14 Clavien grade I, which includes 6 (2%) large renal/retroperitoneal hematomas, 4 (2%) pneumothoraxes, 2 (1%) urinary tract infections, and 2 (1%) atrial fibrillations. There were two (1%) Clavien grade II complications (intestinal perforations). In univariable analysis, larger tumors and more probes were associated with higher risk of complications (all ps < 0.05). In multivariable analysis, larger tumor dimension (odds ratio [OR] = 2.85; 95% confidence interval [CI] = 1.34, 6.05; p = 0.006) was independently associated with major complications. After multivariable adjustments for patient's characteristics such as age, gender, American Society of Anesthesiologists, year of surgery, and histopathology, larger tumor dimension (OR = 2.85; 95%CI = 1.34, 6.05; p = 0.006) and more cryoablation probes (OR = 1.94; 95%CI = 1.36, 2.75; p < 0.001) were independently associated with higher risk of major complications. Conclusions: In a cohort of patients undergoing PCA for T1a small renal mass, larger tumor dimension and more cryoablation probes were independently associated with higher risk of complication. Although PCA is relatively safe and the major complications are infrequent, careful patient selection is crucial. [ABSTRACT FROM AUTHOR]

Objective: We compared postoperative outcomes and quality of life (QoL) between patients who received a nephrostomy tube vs a ureteral stent following percutaneous nephrolithotomy (PCNL) in a prospective, double-blind, randomized manner. Materials and Methods: Between September 2015 and March 2016, we randomized 30 patients undergoing PCNL to receive nephrostomy drainage (Group 1: 8F or 10F) or Double-J ureteral stent (Group 2) at conclusion of surgery. Nephrostomy tubes were removed within 48 hours (before discharge) and ureteral stents were removed at least 2 weeks after surgery. Patients' QoL was assessed with the Wisconsin StoneQOL questionnaire preoperatively and then 7 to 10 days and 30 days following surgery. Inclusion criteria included an uncomplicated procedure, normal preoperative renal function, and clinically insignificant residual stone fragments on postoperative imaging. We calculated the preoperative and postoperative QoL score difference between the two groups. We also evaluated perioperative characteristics, inpatient analgesic requirements, length of stay (LOS), and postsurgical complications. Outcome: Patient characteristics between Groups 1 and 2 were comparable with similar age (58.3 vs 54.7, p = 0.534), gender ratio, and stone burden (276.6 mm2 vs 259 mm2, p = 0.84) and composition. There was no significant difference between perioperative outcomes, including stone-free rate (93.3% vs 86.7%), operative times (125.7 minutes vs 115 minutes, p = 0.29), estimated blood loss (103.3 mL vs 100.7 mL, p = 0.9), LOS (3.2 days vs 1.9 days, p = 0.1), and complications (2 in each group). Inpatient analgesic requirements were also the same (both 21.1 mg, p = 1.0). Assessment of QoL using the Wisconsin StoneQOL questionnaire showed significant differences between preoperative and postoperative health-related QoL in 18 of the 28-question instrument at 7 to 10 days. Patients in Group 2 had significantly worse QoL change and a multitude of negative responses on the StoneQOL assessment, not only those commonly associated with stent irritation. Eighty percent of participants in Group 2 also attributed their complaints to having a stent placed. Both groups had similar QoL status at 30 days after surgery. Conclusion: Despite the literature advocating 'tubeless' PCNL with ureteral stent placement at conclusion of surgery, our randomized prospective study shows that QoL is significantly worse with stent placement than with temporary nephrostomy drainage in the immediate aftermath following PCNL, using a validated QoL assessment instrument specific for nephrolithiasis. [ABSTRACT FROM AUTHOR]

Introduction: Traditional techniques for obtaining percutaneous renal access utilize continuous fluoroscopy. In an attempt to minimize radiation exposure, we describe a novel laser direct alignment radiation reduction technique (DARRT) for percutaneous access and test it in a bench-top model. Methods: In this randomized-controlled bench-top study, 20 medical personnel obtained renal accesses using both the conventional bullseye technique and the laser DARRT. The primary endpoint was total fluoroscopy time. Secondary endpoints included insertion time, puncture attempts, course corrections, and subjective procedural difficulty. In the laser DARRT, fluoroscopy was used with the C-arm positioned with the laser beam at a 30° angle. The access needle and hub were aligned with the laser beam. Effective caliceal puncture was confirmed with fluoroscopy and direct vision. The Paired samples Wilcoxon signed rank test was used for statistical analysis with significance at p < 0.05. Results: A total of 120 needle placements were recorded. Fluoroscopy time for needle access using the laser DARRT was significantly lower than the bullseye technique in all groups as follows: attendings (7.09 vs 18.51 seconds; p < 0.001), residents (6.55 vs 13.93 seconds; p = 0.001), and medical students (6.69 vs 20.22 seconds; p < 0.001). Students rated the laser DARRT easier to use (2.56 vs 4.89; p < 0.001). No difference was seen in total access time, puncture attempts, or course corrections between techniques. Conclusion: The laser DARRT reduced fluoroscopy time by 63%, compared with the conventional bullseye technique. The least experienced users found the laser DARRT significantly easier to learn. This novel technique is promising and merits additional testing in animal and human models. [ABSTRACT FROM AUTHOR]

The safety guidewire has been an integral tool in endourologic percutaneous and ureteroscopic procedures for the last three decades, providing access to the collecting system or ureter in the event of loss of renal contact or ureteral perforation, respectively. However, recent advances in endourologic techniques and instrumentation have obviated the need of routine safety guidewire placement. Today the establishment of a ''through-and-through'' flank to urethral meatus guidewire eliminates the need of an additional guidewire during percutaneous procedures. Likewise, the availability of smaller flexible ureteroscopes, as well as modern ureteral access sheaths, has reduced the necessity of safety guidewire placement in ureteroscopic procedures. Herein, we trace the historical development of the safety guidewire concept, review recent advances in technologies that have obsoleted the safety guidewire, and evaluate recent data suggesting that continued use of a safety guidewire during ureteroscopic procedures may indeed be counterproductive. [ABSTRACT FROM AUTHOR]

Purpose: Ureteral stent-related pain is a well-known side effect of stent placement. To date, there is a paucity of resources that address this topic. Herein, we present theories on stent pain pathophysiology, summarize available pain outcome data for different stent designs, and provide an overview of the management of stent pain, including preplacement modifiers, medical management, and other considerations. Materials and Methods: This narrative review focused primarily on articles indexed in the PubMed®, Google Scholar™, and EMBASE databases. No formal search strategy was used and no meta-analysis of data was performed. Results: Stent pain pathophysiology is multifactorial and likely a result of mucosal irritation along with retrograde reflux of urine. While there is a consensus on the lack of association between stent length, diameter, and stent-related flank pain, stents should be properly sized so as to prevent dislodgement. Insufficient data exist comparing stent materials and durometry. Multiple drug-eluting stents are in development and have demonstrated promising early results. Alpha-blockers have shown efficacious results and should be considered along with or in combination with anticholinergics and nonsteroidal anti-inflammatory drugs (NSAIDs) in the treatment of ureteral stent-related symptoms, with judicious consideration of their side effect profiles. Periur-eteral botulinum toxin A injections are a promising, novel treatment modality. Conclusions: Ureteral stent pain is common and multiple modalities have been studied and are in clinical use for its treatment. Care should be taken to avoid placement of stents if possible, with continual reassessment of indications to maintain stents in patients. Relative heterogeneity among studies and small sample sizes make creating specific evidence-based pain management recommendations challenging. Alpha-blockers, antimuscarinics, and NSAIDs are all generally well tolerated and effectively reduce symptoms, but patient-specific factors must be the paramount consideration when choosing monotherapy or combination therapy. Future studies are needed to better define ideal material characteristics and pharmacologic treatments. [ABSTRACT FROM AUTHOR]

Objective: To assess the feasibility and safety of a modified retroperitoneoscopic technique in supine position for the primary tumors located below the level of renal pedicle. Materials and Methods: In this retrospective study, 27 patients with primary retroperitoneal tumors located below the level of renal pedicle were recruited from January 2009 till now. The mean age of patients was 49.0 years (36-66 years). The average body mass index was 21.1 ± 1.4kg/m². The retroperitoneoscopic resections were performed in supine position for all patients. The perioperative outcomes were collected and analyzed. Results: All cases were performed by the modified technique without converting to open surgery. The mean operation time was 98.3 ± 12.8 min, with a mean estimated blood loss of 94.4 ± 42.5 mL. There were four patients suffering from intraoperative complications, one with the inferior vena cava (IVC) injury, one with the lumbar vein injury, and other two with the peritoneum breach. Postoperatively, the median bowel recovery time was 2 days (range: 1-3 days), and the mean length of stay after operation was 2.9 ± 1.0 days. Additionally, compared with the tumors located around the aorta (region B), a longer operation time was needed with tumors located around the IVC (region A) (A vs B: 105.8 ± 10.2 vs 91.2 ± 14.4, p = 0.02). Histopathology confirmed paraganglioma in 5 cases, schwannoma in 10 cases, and ganglioneuroma in 12 cases. After follow-up of 12-72 months, no recurrences have been identified. Conclusion: Our modified retroperitoneoscopic technique in supine position was proven to be safe and effective for the treatment of primary retroperitoneal tumors, especially suitable for the tumors located below the level of the renal pedicle. [ABSTRACT FROM AUTHOR]

Background: Computer based surgical training is believed to be capable of providing a controlled virtual environment for medical professionals to conduct standardized training or new experimental procedures on virtual human body parts, which are generated and visualised three-dimensionally on a digital display unit. The main objective of this study was to conduct virtual phacoemulsification cataract surgery to compare performance by users with different proficiency on a virtual reality platform equipped with a visual guidance system and a set of performance parameters.Methods: Ten experienced ophthalmologists and six medical residents were invited to perform the virtual surgery of the four main phacoemulsification cataract surgery procedures - 1) corneal incision (CI), 2) capsulorhexis (C), 3) phacoemulsification (P), and 4) intraocular lens implantation (IOL). Each participant was required to perform the complete phacoemulsification cataract surgery using the simulator for three consecutive trials (a standardized 30-min session). The performance of the participants during the three trials was supported using a visual guidance system and evaluated by referring to a set of parameters that was implemented in the performance evaluation system of the simulator.Results: Subjects with greater experience obtained significantly higher scores in all four main procedures - CI1 (ρ = 0.038), CI2 (ρ = 0.041), C1 (ρ = 0.032), P2 (ρ = 0.035) and IOL1 (ρ = 0.011). It was also found that experience improved the completion times in all modules - CI4 (ρ = 0.026), C4 (ρ = 0.018), P6 (ρ = 0.028) and IOL4 (ρ = 0.029). Positive correlation was observed between experience and anti-tremor - C2 (ρ = 0.026), P3 (ρ = 0.015), P4 (ρ = 0.042) and IOL2 (ρ = 0.048) and similarly with anti-rupture - CI3 (ρ = 0.013), C3 (ρ = 0.027), P5 (ρ = 0.021) and IOL3 (ρ = 0.041). No significant difference was observed between the groups with regards to P1 (ρ = 0.077).Conclusions: Statistical analysis of the results obtained from repetitive trials between two groups of users reveal that augmented virtual reality (VR) simulators have the potential and capability to be used as a feasible proficiency assessment tool for the complete four main procedures of phacoemulsification cataract surgery (ρ < 0.05), indicating the construct validity of the modules simulated with augmented visual guidance and assessed through performance parameters. [ABSTRACT FROM AUTHOR]

The main functions of biological adhesives and sealants are to repair injured tissues, reinforce surgical wounds, or even replace common suturing techniques. In general surgery, adhesives must match several requirements taking into account clinical needs, biological effects, and material features; these requirements can be fulfilled by specific polymers. Natural or synthetic polymeric materials can be employed to generate three-dimensional networks that physically or chemically bind to the target tissues and act as hemostats, sealants, or adhesives. Among them, fibrin, gelatin, dextran, chitosan, cyanoacrylates, polyethylene glycol, and polyurethanes are the most important components of these interfaces; various aspects regarding their adhesion mechanisms, mechanical performance, and resistance to body fluids should be taken into account to choose the most suitable formulation for the target application. This review aims to describe the main adhesives and sealant materials for general surgery applications developed in the past decades and to highlight the most important aspects for the development of future formulations. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 626-639, 2016. [ABSTRACT FROM AUTHOR]

We report the overall rate, locations and predictive factors of positive surgical margins (PSMs) in 271 patients with high-risk prostate cancer. Between April 2008 and October 2011, we prospectively collected data from patients classified as D'Amico high-risk who underwent robot-assisted laparoscopic radical prostatectomy. Overall rate and location of PSMs were reported. Stepwise logistic regression models were fitted to assess predictive factors of PSM. The overall rate of PSMs was 25.1% (68 of 271 patients). Of these PSM, 38.2% (26 of 68) were posterolateral (PL), 26.5% (18 of 68) multifocal, 16.2% (11 of 68) in the apex, 14.7% (10 of 68) in the bladder neck, and 4.4% (3/68) in other locations. The PSM rate of patients with pathological stage pT2 was 8.6% (12 of 140), 26.6% (17 of 64) of pT3a, 53.3% (32/60) of pT3b, and 100% (7 of 7) of pT4. In a logistic regression model including pre-, intra-, and post-operative parameters, body mass index (odds ratio [OR]: 1.09; 95% confidence interval [CI]: 1.01-1.19, P = 0.029), pathological stage (pT3b or higher vs pT2; OR: 5.14; 95% CI: 1.92-13.78; P = 0.001) and percentage of the tumor (OR: 46.71; 95% CI: 6.37-342.57; P < 0.001) were independent predictive factors for PSMs. The most common location of PSMs in patients at high-risk was the PL aspect, which reflects the reported tumor aggressiveness. The only significant predictive factors of PSMs were pathological outcomes, such as percentage of the tumor in the specimen and pathological stage. [ABSTRACT FROM AUTHOR]

Key content: Trainees face many challenges in learning the skill set required to perform laparoscopic surgery.The time spent in the operating room has been detrimentally impacted upon since the implementation of the European Working Time Directive. In order to address the deficit, surgical educators have looked to the benefits enjoyed in the aviation and sports industries in using simulation training. Learning objectives: To summarise the current understanding of the neuropsychological basis of learning a psychomotor skill.To clarify factors that influence the acquisition of these skills.To summarise how this information can be used in teaching and assessment of laparoscopic skills. Ethical issues: The use of virtual reality simulators may be able to form a part of the aptitude assessment in the selection process, in order to identify trainees with the desired attributes to progress into the training programmes. However, as skill improves with practice, is it ethical to exclude novices with poor initial performance assessment before allowing them the opportunities to improve? [ABSTRACT FROM AUTHOR]

White light cystoscopy and the concise documentation of pathological findings are standard diagnostic procedures in urology. Additional imaging modalities and technical innovations may support clinicians in the detection of bladder tumors. Modern endoscopy systems provide ultra-high-resolution imaging and the option of digital contrast enhancement. Photodynamic diagnostics and narrow band imaging are well-established in clinical routine and have shown significant benefits in the detection of bladder cancer. By means of multispectral imaging, different modalities can now be combined in real-time. Probe-based procedures such as optical coherence tomography (OCT) or Raman spectroscopy can further contribute to advanced imaging through an "optical biopsy" which may primarily improve diagnostics in the upper urinary tract. The aim of all techniques is to optimize the detection rate in order to achieve a more accurate diagnosis, resection and lower recurrence rates. Current research projects aim to digitalize the documentation of endoscopy and also make it more patient- and user-friendly. In the future, the use of image processing and artificial intelligence may automatically support the surgeon during endoscopy.

Background and Purpose: Endoureterotomy is a viable option for treating patients with benign ureteral stricture. We compared the efficacy and safety of double versus single ureteral stent placement after laser endoureterotomy. Patients and Methods: This study included 55 patients with benign ureteral strictures; all patients underwent retrograde laser endoureterotomy. Patients were randomized either to single or double ureteral stents. Single stents were placed in 27 ureters while double stents were placed in 28 ureters. The stent diameter used was 7 F, and stents were indwelling for 8 weeks. Imaging was performed 1 month after stent removal and repeated regularly every 3 months. Clinical characteristics, operative results, and functional outcomes were compared for strictures managed in both groups. Success was evaluated both subjectively and objectively. Results: Fifty-five patients with a mean age of 46 (16-75) years had benign ureteral strictures; the mean stricture length was 1.92 (1-3) cm. The mean follow-up was 25.7 (9-42) months. The overall success rate was 67.3% (37 patients) with no radiologic evidence of obstruction, 6 (10.9%) patients showed symptomatic improvement while 12 (21.8%) patients underwent surgical reconstruction. Success was significantly higher for ureteral strictures (>1.5 cm) managed with double stent placement (82.4%), compared with single stent placement (38.9%) with a P value of 0.009. Conclusions: Double stent placement of the ureter after laser endoureterotomy achieved a higher success rate compared with single stent placement in cases of benign ureteral strictures. Although ureteral strictures (≤1.5 cm) achieved better outcome after laser endoureterotomy, strictures (>1.5 cm) favored better with double stent versus single stent placement. [ABSTRACT FROM AUTHOR]

This study aimed at reviewing a contemporary series of patients who underwent robotic renal and adrenal surgery by a single surgeon at a tertiary referral academic medical center over a 6-year period, specifically focusing on the unique and serious complication of post-operative rhabdomyolysis of the dependent lower extremity. The cases of 315 consecutive patients who underwent robotic upper tract surgery over a 6-year period from August 2008 to June 2014 using a standardized patient positioning were reviewed and analyzed for patient characteristics and surgical variables that may be associated with the development of post-operative rhabdomyolysis. The incidence of post-operative rhabdomyolysis in our series was 3/315 (0.95 %). All three affected patients had undergone robotic nephroureterectomy. Those patients who developed rhabdomyolysis had significantly higher mean Body Mass Index, Charlson Comorbidity Index, and median length of stay than those who did not. The mean OR time in the rhabdomyolysis group was noted to be 52 min longer than the non-rhabdomyolysis group, though this value did not reach statistical significance. Given the trends of increasing obesity in the United States and abroad as well as the continued rise in robotic upper tract urologic surgeries, urologists need to be increasingly vigilant for recognizing the risk factors and early treatment of the unique complication of post-operative rhabdomyolysis. [ABSTRACT FROM AUTHOR]

Background: Ureteral obstruction caused by extrinsic compression is often associated with intra-abdominal cancers. Internal drainage with ureteral stents is typically the first-line therapy to relieve such obstructions. Novel designs of ureteral stents made of different materials have been invented to achieve better drainage. In this study, we described the functional outcomes of a Resonance metallic ureteral stent (Cook Medical, Bloomington, Indiana, USA) in patients with malignant ureteral obstruction and compare the functional duration of Resonance stents with regular polymeric stents in the same cohort. Methods: Cancer patients who received polymeric stents and subsequent Resonance stents for ureteral obstruction between July 2009 and November 2012 were included in a chart review. Stent failure was detected by clinical symptoms, imaging studies, and renal function tests. The functional durations of each stent were calculated, and possible factors affecting stent patency were investigated. Results: A total of 50 stents were successfully inserted into 50 ureteral units in 42 patients with malignant ureteral obstruction. There were 7 antegrade stents and 43 retrograde stents. There were no major complications. Stent-related symptoms were similar in both kinds of stents. After polymeric stents were replaced with Resonance metallic stents, hydronephrosis subsided or remained stable in 90% (45/50) of the ureteral units. Serum creatinine decreased or remained stable in 90% (38/42) of these patients. The Resonance stent exhibited a mean increase in functional duration of 4 months compared with the polymeric stents (p<0.0001), and 50% (25/50) of the Resonance stents exhibited a significant increase in functional duration (more than 3 months). Pre-operative serum creatinine < 2 was associated with a substantial increase in stent duration. Conclusions: Resonance stents are effective and safe in relieving malignant ureteral obstructions after polymeric stents failure. Resonance stents can provide a longer functional duration than polymeric stents and should be offered as an option for internal drainage. [ABSTRACT FROM AUTHOR]

Background: Advanced bipolar radiofrequency (RF) energy-based devices are increasingly used for non-vascular tissue sealing, transection and anastomosis. Although the potential to further develop this technology is clear, the limitations of commercially available devices are poorly understood. This systematic review examines the current utilisation of advanced bipolar RF fusion technology for non-vascular applications in thoracic and abdominal tissues and organs. Methods: Medline, Embase, Web of Science and Cochrane library databases were searched. Studies examining the non-vascular application of advanced bipolar RF technology in the abdomen and thorax were assessed. Measurement of seal sufficiency and the extent of tissue injury induced by bipolar RF energy application were the main outcomes of interest. Results: Forty-six animal and human studies conducted in and ex vivo across a range of tissue types, met the inclusion criteria. The diversity of study protocols together with the heterogeneity of their outcomes prevented pooled analysis. However, the experimental animal studies assessed suggest that bipolar RF fusion devices are capable of effectively sealing most tissue types with the notable exception of large caliber bronchi (>4 mm) and bile ducts, where the rate of seal failure was unacceptably high. Human studies were additionally found to predominantly use bipolar RF technology as a means of parenchymal and ductal occlusion. A similar trend was seen amongst animal studies with only a handful of papers examining bipolar RF energy use for (bowel) anastomosis. Conclusion: Bipolar RF fusion devices are capable of safely sealing a variety of thoracic and anterior abdominal tissues with an injury and leakage profile comparable to established technologies. Although thermal monitoring is increasingly sophisticated and multimodal, consistent real time tracking of a multitude of parameters is necessary in order to expand RF fusion technology utilisation to complete an array of tasks such as vessel ligation, ductal obliteration and anastomosis in the open and laparoscopic environments. [ABSTRACT FROM AUTHOR]

Background:The diffusion of minimally invasive radical prostatectomy (MIRP) in the United States may have led to adverse patient outcomes due to rapid surgeon adoption and collective inexperience. We hypothesized that throughout the early period of minimally invasive surgery, MIRP patients had inferior outcomes as compared with those who had open radical prostatectomy (ORP).Methods:We used the Surveillance, Epidemiology and End Results-Medicare dataset and identified men who had ORP and MIRP for prostate cancer from 2003-2009. Study endpoints were receipt of subsequent cancer treatment, and evidence of postoperative voiding dysfunction, erectile dysfunction (ED) and bladder outlet obstruction. We used proportional hazards regression to estimate the impact of surgical approach on each endpoint, and included an interaction term to test for modification of the effect of surgical approach by year of surgery.Results:ORP (n=5362) and MIRP (n=1852) patients differed in their clinical and demographic characteristics. Controlling for patient characteristics and surgeon volume, there was no difference in subsequent cancer treatments (hazard ratio (HR) 0.89, 95% confidence interval (CI) 0.76-1.05), although MIRP was associated with a higher risk of voiding dysfunction (HR 1.31, 95% CI 1.20-1.43) and ED (HR 1.43, 95% CI 1.31-1.56), but a lower risk of bladder outlet obstruction (HR 0.86, 95% CI 0.75-0.97). There was no interaction between approach and year for any outcome. When stratifying the analysis by year, MIRP consistently had higher rates of ED and voiding dysfunction with no substantial improvement over time.Conclusions:MIRP patients had adverse urinary and sexual outcomes throughout the diffusion of minimally invasive surgery. This may have been a result of the rapid adoption of robotic surgery with inadequate surgeon preparedness. [ABSTRACT FROM AUTHOR]

The full metallic double-J ureteral stent (MS) was introduced as a method for providing long-term drainage in malignant ureteral obstruction. Experimental evaluation of the MS revealed that its mechanical features allow efficient drainage in difficult cases, which could not be managed by the insertion of a standard polymeric double-J stent. Clinical experience with the MS showed controversial results. Careful patient selection results in efficient long-term management of malignant ureteral obstruction. The use of the MS should also be considered in selected benign cases. Major complications are uncommon and the minor complications should not hinder its use. Experience in pediatric patients is limited and warrants additional study. The cost-effectiveness of the MS seems to be appropriate for long-term treatment. Further investigation with comparative clinical trials would document the outcome more extensively and establish the indications as well as the selection criteria for the MS. [ABSTRACT FROM AUTHOR]

The purpose of the study was to systematically review and assess the safety and efficacy of hemostatic agents in tubeless percutaneous nephrolithotomy. Original studies on the use of hemostatic agents in tubeless percutaneous nephrolithotomy (PCNL) from January 2001 to March 2014 were searched in Ovid, Science Direct, Pubmed, and Embase by two independent reviewers. A drop in hemoglobin (Hb), analgesic requirements, length of hospital stay, and necessity for blood transfusions were compared using Review Manager 5.2. The methods were done according to the Cochrane Handbook for interventional systematic reviews and written based on the PRISMA Statement. Seven studies involving 351 patients met the inclusion criteria for the meta-analysis. The baseline characteristics were comparable in all of the studies. The results showed that the length of hospital stay was less in the experimental group than in the control group ( P < 0.05). There were no significant statistical differences in terms of a drop in Hb, analgesic requirements, and the necessity for a blood transfusion between the two groups ( P > 0.05). The meta-analysis indicated that the hemostatic agents in tubeless PCNL were not expected to be unsafe or mandatory, but that they were expected to be expensive. We concluded that hemostatic agents might not be necessary in tubeless PCNL. [ABSTRACT FROM AUTHOR]

Objectives To investigate the long-term outcomes of hand-assisted laparoscopic radical nephrectomy compared with those of open nephrectomy. Methods Hand-assisted laparoscopic radical nephrectomy was carried out in 132 patients with T1 renal cell carcinoma (between November 1999 and November 2008). Their outcomes were compared with those of 61 patients treated with open nephrectomy. The durations of follow up were 6-121 months (median 65 months) and 7-146 months (median 84 months) in the hand-assisted laparoscopic radical nephrectomy and open nephrectomy groups, respectively. Results The 7-year recurrence-free rates were 88.5 and 85.6% in the hand-assisted laparoscopic radical nephrectomy and open nephrectomy groups, respectively, showing no significant difference between the two groups. The 7-year cancer-specific survival rates were 92.3 and 91.4% in the hand-assisted laparoscopic radical nephrectomy and open nephrectomy groups, respectively, showing no significant difference between the two groups. Also, the 10-year recurrence-free rates were 85.4 and 78.1% in the hand-assisted laparoscopic radical nephrectomy and open nephrectomy groups, respectively. When changes in the recurrence-free rate were analyzed using the Kaplan- Meier method, no significant difference was observed between the two groups. The 10-year cancer-specific survival rates were 91.8 and 87.9% for hand-assisted laparoscopic radical nephrectomy and open nephrectomy, respectively, showing no significant difference between the groups. Conclusions Hand-assisted laparoscopic radical nephrectomy might be comparable with open nephrectomy with regard to long-term cancer control. [ABSTRACT FROM AUTHOR]

This paper introduces admission control policies for WiMAX networks, which aim to reach three main goals: restrict the number of simultaneous connections in the system so that the resources available for the uplink scheduler are sufficient to guarantee the quality-of-service requirements for each connection, support the service provider expectations by maximizing the revenue, and maximize user satisfaction by granting additional resources. The optimal solution to meet these goals is non-deterministic polynomial-time hard and therefore cannot be solved in acceptable polynomial time. For this reason, both optimal and polynomial time heuristic solutions are introduced. Simulation experiments are used to evaluate and compare the proposed policies. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

To evaluate the role of hemostatic agents used for nephrostomy tract closure after tubeless percutaneous nephrolithotomy (PCNL). A systematic review of Pubmed, Embase and Cochrane was performed. All studies that compared hemostatic agents with common methods (silk stitch or pressure dressing) were included. The analyzed outcomes were hospital stay, operative time, blood loss, transfusion rate, fever rate, and complication rate. A total of eight articles including six RCTs met our criteria. Hemostatic agents showed short hospital stay (MD −4.54, 95 % CI −6.78 to −2.36, p < 0.0001). There was no difference between hemostatic agents and common methods on operative time (MD 2.00, 95 % CI −17.32 to 21.33, p = 0.84), blood loss (MD −0.19, 95 % CI −0.41 to 0.03, p = 0.08), transfusion rate (OR 1.42, 95 % CI 0.34-5.96, p = 0.63), fever rate (OR 1.02, 95 % CI 0.33-3.12, p = 0.97) and complication rate (OR 1.02, 95 % CI 0.33-3.12, p = 0.97). Eight studies including six RCTs showed that use of hemostatic agents was safe. Hemostatic agents showed short hospital stay. There were no difference between hemostatic agents and common methods on blood loss, transfusion rate, fever rate, and complication rate. [ABSTRACT FROM AUTHOR]

SUMMARY Subscriber stations located in different places encounter various interferences in an IEEE 802.16 network, resulting in that their communication channels experience varying channel conditions. Thus, an excellent bandwidth allocation algorithm should not only satisfy various QoS required by heterogeneous traffic, but also consider the channel quality to maximize bandwidth utilization. In this paper, a bandwidth allocation algorithm with channel quality awareness and QoS guarantee, called CQQ, is proposed. CQQ not only satisfies each connection's QoS requirement, but also dynamically adjusts the downlink/uplink bandwidth to match current downlink/uplink traffic ratio. CQQ allocates more bandwidth to the connections having better channel quality by applying weighted fair queuing strategy to raise the bandwidth usage. CQQ provides lower delay violation ratio and higher goodput than the previous algorithms, as observed from the simulation results. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]