Abstract Background Posterior reconstruction (PR) of the rhabdosphincter has been previously described during retropubic radical prostatectomy, and shorter times to return of urinary continence were ...reported using this technical modification. This technique has also been applied during robot-assisted radical prostatectomy (RARP); however, contradictory results have been reported. Objective We describe here a modified technique for PR of the rhabdosphincter during RARP and report its impact on early recovery of urinary continence and on cystographic leakage rates. Design, setting, and participants We analyzed 803 consecutive patients who underwent RARP by a single surgeon over a 12-mo period: 330 without performing PR and 473 with PR. Surgical procedure The reconstruction was performed using two 6-in 3-0 Poliglecaprone sutures tied together. The free edge of the remaining Denonvillier’s fascia was identified after prostatectomy and approximated to the posterior aspect of the rhabdosphincter and the posterior median raphe using one arm of the continuous suture. The second layer of the reconstruction was then performed with the other arm of the suture, approximating the posterior lip of the bladder neck and vesicoprostatic muscle to the posterior urethral edge. Measurements Continence rates were assessed with a self-administrated, validated questionnaire (Expanded Prostate Cancer Index Composite) at 1, 4, 12, and 24 wk after catheter removal. Continence was defined as the use of “no absorbent pads.” Cystogram was performed in all patients on postoperative day 4 or 5 before catheter removal. Results and limitations There was no significant difference between the groups with respect to patient age, body mass index, prostate-specific antigen levels, prostate weight, American Urological Association symptom score, estimated blood loss, operative time, number of nerve-sparing procedures, and days with catheter. In the PR group, the continence rates at 1, 4, 12, and 24 wk postoperatively were 22.7%, 42.7%, 91.8%, and 96.3%, respectively; in the non-PR group, the continence rates were 28.7%, 51.6%, 91.1%, and 97%, respectively. The modified PR technique resulted in significantly higher continence rates at 1 and 4 wk after catheter removal ( p = 0.048 and 0.016, respectively), although the continence rates at 12 and 24 wk were not significantly affected ( p = 0.908 and p = 0.741, respectively). The median interval to recovery of continence was also statistically significantly shorter in the PR group (median: 4 wk; 95% confidence interval CI: 3.39–4.61) when compared to the non-PR group (median: 6 wk; 95% CI: 5.18–6.82; log-rank test, p = 0.037). Finally, the incidence of cystographic leaks was lower in the PR group (0.4% vs 2.1%; p = 0.036). Although the patients’ baseline characteristics were similar between the groups, the patients were not preoperatively randomized and unknown confounding factors may have influenced the results. Conclusions Our modified PR combines the benefits of early recovery of continence reported with the original PR technique with a reinforced watertight closure of the posterior anastomotic wall. Shorter interval to recovery of continence and lower incidence of cystographic leaks were demonstrated with our PR technique when compared to RARP with no reconstruction.
An experimental study is performed to explore the effect of swirl and number of swirler vanes on combustion characteristics of methane inverse diffusion flame (IDF) using 30
0
swirler. Influence of ...varying the number of vanes (4, 6 and 8) on structure and appearance of IDFs is studied. Swirling IDFs are observed with dual flame structure. Length of both IDFs depends on Reynolds number (
Re
air
) and equivalence ratio (
Φ
). Temperature measured along the centerline in swirling IDF is greater than non-swirling IDF. Radial temperature distribution shows that the swirling effect intensify combustion process. Effect of
Φ
on CO emission revels that non-swirling IDFs emit more CO compared to swirling IDFs. The lowest NO
x
emission is observed in swirling IDFs with 6 vanes. Study indicates that the IDFs with swirl results in low emission of CO and NO
x
.
Abstract Context Radical retropubic prostatectomy (RRP) has long been the most common surgical technique used to treat clinically localized prostate cancer (PCa). More recently, robot-assisted ...radical prostatectomy (RARP) has been gaining increasing acceptance among patients and urologists, and it has become the dominant technique in the United States despite a paucity of prospective studies or randomized trials supporting its superiority over RRP. Objective A 2-d consensus conference of 17 world leaders in prostate cancer and radical prostatectomy was organized in Pasadena, California, and at the City of Hope Cancer Center, Duarte, California, under the auspices of the European Association of Urology Robotic Urology Section to systematically review the currently available data on RARP, to critically assess current surgical techniques, and to generate best practice recommendations to guide clinicians and related medical personnel. No commercial support was obtained for the conference. Evidence acquisition A systematic review of the literature was performed in agreement with the Preferred Reporting Items for Systematic Reviews and Meta-analysis statement. Evidence synthesis The results of the systematic literature review were reviewed, discussed, and refined over the 2-d conference. Key recommendations were generated using a Delphi consensus approach. RARP is associated with less blood loss and transfusion rates compared with RRP, and there appear to be minimal differences between the two approaches in terms of overall postoperative complications. Positive surgical margin rates are at least equivalent with RARP, but firm conclusions about biochemical recurrence and other oncologic end points are difficult to draw because the follow-up in existing studies is relatively short and the overall experience with RARP in locally advanced PCa is still limited. RARP may offer advantages in postoperative recovery of urinary continence and erectile function, although there are methodological limitations in most studies to date and a need for well-controlled comparative outcomes studies of radical prostatectomy surgery following best practice guidelines. Surgeon experience and institutional volume of procedures strongly predict better outcomes in all relevant domains. Conclusions Available evidence suggests that RARP is a valuable therapeutic option for clinically localized PCa. Further research is needed to clarify the actual role of RARP in patients with locally advanced disease.
Rhesus monkeys are a non-rodent species employed in the preclinical safety evaluation of pharmaceuticals and biologics. These nonhuman primate species have been increasingly used in biomedical ...research because of the similarity in their ionic mechanisms of repolarization with humans. Heart rate and QT interval are two primary endpoints in determining the pro-arrhythmic risk of drugs. As heart rate and QT interval have an inverse relationship, any change in heart rate causes a subsequent change in QT interval. This warrants for calculation of a corrected QT interval. This study aimed to identify an appropriate formula that best corrected QT for change in heart rate. We employed seven formulas based on source-species type, clinical relevance, and requirements of various international regulatory guidelines. Data showed that corrected QT interval values varied drastically for different correction formulas. Equations were compared on their slope values based on QTc versus RR plots. The rank order of the slope for different formulas was (closest to farthest from zero) QTcNAK, QTcHAS, QTcBZT, QTcFRD, QTcVDW, QTcHDG, and QTcFRM. QTcNAK emerged to be the best correcting formula in this study. It showed the least correlation with the RR interval (r = −0.01) and displayed no significant difference amongst the sexes. As there is no universally recognized formula for preclinical use, the authors recommend developing a best-case scenario model for specific study designs and individual organizations. The data from this research will be helpful in deciding an appropriate QT correction formula for the safety assessment of new pharmaceuticals and biologics.
Pulsating heat pipe (PHP) is one of the prominent research areas in the family of heat pipes. Heat transfer and fluid flow mechanism associated with PHP are quite involved. The analytical models are ...simple in nature and limited in scope and applicability. The regression models and Artificial Neural Network (ANN) are also limited to a number of input parameters, their ranges and accuracy. The present paper discusses the thermal performance prediction models of a PHP based on ANN and RCA approach. Totally 1652 experimental data are collected from the literature (2003–2017). Nine major influencing input variables are considered for the first time to develop the prediction models. Feed-forward back-propagation neural network is developed and verified. Backward regression analysis is used in RCA-based regression model. Linear and power-law regression correlations are developed for input heat flux in terms of dimensionless Kutateladze (
Ku
) number, which is a function of Jakob number (
Ja
), Morton number (
Mo
), Bond number (
Bo
), Prandtl number (
Pr
) and geometry of a PHP. The prediction accuracy of present regression models (
R
2
= 0.95) is observed to be better as compared with literature-based correlations.
Robot-assisted laparoscopic radical prostatectomy (RALP) is an evolving minimally invasive treatment of for localized prostate cancer. We present our experience of 1500 consecutive cases with an ...analysis of perioperative outcomes.
Fifteen hundred consecutive RALPs were performed by a single surgeon (VRP). Following Institutional Review Board approval, clinical coordinators performed prospective intraoperative and postoperative data collection. Functional outcomes were assessed using validated self-administered questionnaires.
Mean OR time from skin incision to fascial closure (the time that the surgeon was present) was 105 minutes (55-300). Mean EBL was 111 cc (50-500). Ninety-seven percent of patients were discharged home on postoperative day 1. The overall complication rate was 4.3% with no mortalities. The positive margin rate (PMR) was 9.3% overall. PMR was 4% for pT2, 34% for T3 and 40% for pathologic stage T4.
Our initial series represents one of the largest published series for perioperative outcomes of robotic assisted prostatectomy. Our data demonstrates the feasibility, safety and efficacy of the procedure.
Abstract Context In 2001, Rocco et al. described a surgical technique whose aim was the reconstruction of the posterior musculofascial plate after radical prostatectomy (RP) to improve early return ...to urinary continence. Since then, many surgeons have applied this technique—either as it was described or with some modification—to open, laparoscopic, and robot-assisted RP. Objective To review the outcomes reported in comparative studies analysing the influence of reconstruction of the posterior aspect of the rhabdosphincter after RP. The main outcome evaluated was urinary continence at 3–7 d, 30–45 d, 90 d, 180 d, and 1 yr after catheter removal. Evidence acquisition A systematic review of the literature was performed in November 2011, searching the Medline, Embase, Scopus, and Web of Science databases. A “free-text” protocol using the terms posterior reconstruction of the rhabdosphincter, posterior rhabdosphincter , and early continence was applied. Studies published only as abstracts and reports from meetings were not included in this review. One thousand seven records were retrieved from the Medline database, 1541 from the Embase database, 1357 from the Scopus database, and 1041 from the Web of Science database. The authors reviewed the records to identify studies comparing cohorts of patients who underwent RP with or without restoration of the posterior aspect of the rhabdosphincter. Only papers evaluating use of this technique as the only technical modification among the groups were included. A cumulative analysis was conducted using Review Manager v.5.1 software (Cochrane Collaboration, Oxford, UK). Evidence synthesis Eleven studies were identified in the literature search, including two randomised controlled trials (RCTs), which were negative studies. The cumulative analysis of comparative studies showed that reconstruction of the posterior musculofascial plate improves early return of continence within the first 30 d after RP ( p = 0.004), while continence rates 90 d after surgery are not affected by use of the reconstruction technique. The statistical significance of the reconstruction seems to decrease when higher continence rates are reported. Use of posterior rhabdosphincter reconstruction does not seem to be related to positive surgical margin (PSM) rates or with complications like acute urinary retention (AUR) and bladder neck stricture (BNS). Some studies suggested lower anastomotic leakage rates with the posterior musculofascial plate reconstruction technique. Conclusions The role of reconstruction of the posterior musculofascial plate in terms of earlier continence recovery is encouraging but still controversial. Methodological flaws and poor surgical standardisation seem to be the major causes. In two RCTs and one parallel (not randomised) group trial, posterior rhabdosphincter reconstruction offered no significant advantage for return of early continence after RP. No significant complications related to the posterior musculofascial plate reconstruction technique have been reported so far. A multicentre RCT is necessary to clarify the possible role of the technique in terms of earlier continence recovery.
Robot-assisted radical prostatectomy (RARP) is hampered by side effects that may have a serious impact on quality of life, particularly stress urinary incontinence. Continence rates may be improved ...by surgical reconstruction of the pelvic floor.
Video illustrations of different surgical techniques may be particularly worthwhile for practicing urologists in understanding the pelvic-floor anatomy and in the training of residents and fellows in urology.
We describe and video-illustrate commonly performed pelvic reconstructive techniques in RARP, as performed by experts in the field.
Surgical techniques have been described, such as posterior musculofascial reconstruction, anterior reconstruction and periurethral suspension, preservation of membranous urethral lengthening, bladder-neck reconstruction, and combinations.
An overview of continence rates of the different techniques is given.
All reconstructive surgical techniques result in similar short-term continence rates and good-to-excellent outcomes 1yr after surgery. There are only a few randomized clinical trials comparing a reconstructive technique with “no reconstruction” or a different reconstructive technique, and outcomes are conflicting.
Although many of the procedures report a benefit with respect to early continence, benefits seem to diminish with longer follow-up. Whether any of the reconstructive techniques is superior to another is a matter of study.
Early continence rates might be improved by surgical reconstruction of the pelvic floor.
We describe and video-illustrate the most frequently performed pelvic reconstructive techniques in robot-assisted radical prostatectomy aimed at lowering stress urinary incontinence. Many of the procedures report a benefit with respect to early continence, which seems to diminish with longer follow-up.
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