Gynecological organ involvement at robot-assisted radical cystectomy in females: Is anterior exenteration necessary?

INTRODUCTION: We aimed to investigate patient and disease variables associated with gynecological organ invasion in females with bladder cancer at the time of robot-assisted radical cystectomy (RARC). METHODS: We conducted a retrospective review of female patients who underwent robot-assisted anterior pelvic exenteration (RAAE) between 2005 and 2016. Patients were divided into two groups: those with gynecological organ involvement at RAAE and those without. Data were reviewed for perioperative and pathological outcomes. Kaplan-Meier method was used to depict survival outcomes. Multivariable stepwise regression analysis was performed to identify predictors of gynecological organ involvement. RESULTS: A total of 118 female patients were identified; 17 (14%) showed evidence of gynecological organ invasion at RAAE. Patients with gynecological organ invasion had more lymphovascular invasion at transurethral resection of bladder tumour (TURBT) (82% vs. 46%; p=0.006), trigonal tumours at TURBT (59% vs. 18%; p=0.001), multifocal disease (65% vs. 33%; p=0.01), pN+ (71% vs. 22%; p<0.001), positive surgical margins (24% vs. 4%; p=0.02), and they less commonly demonstrated pure urothelial carcinoma at TURBT (18% vs. 66%; p<0.001). On multivariate analysis, significant predictors of gynecological organ invasion were pN positive disease (odds ratio [OR] 6.48; 95% confidence interval [CI] 1.64-25.51; p=0.008), trigonal tumour location (OR 5.72; 95% CI 1.39-23.61; p=0.02), and presence of variant histology (OR18.52; 95% CI 3.32-103.4; p=0.001). CONCLUSIONS: Patients with trigonal tumours, variant histology, and nodal involvement are more likely to have gynecological organs invasion at RAAE. This information may help improve counselling of patients and better identify candidates for gynecological organ-sparing cystectomy.

Development of a Patient-Based Model for Estimating Operative Times for Robot-Assisted Radical Prostatectomy.

OBJECTIVES: To develop a methodology for predicting operative times for robot-assisted radical prostatectomy (RARP) using preoperative patient, disease, procedural, and surgeon variables to facilitate operating room (OR) scheduling. METHODS: The model included preoperative metrics: body mass index (BMI), American Society of Anesthesiologists score, clinical stage, National Comprehensive Cancer Network risk, prostate weight, nerve-sparing status, extent and laterality of lymph node dissection, and operating surgeon (six surgeons were included in the study). A binary decision tree was fit using a conditional inference tree method to predict operative times. The variables most associated with operative time were determined using permutation tests. Data were split at the value of the variable that results in the largest difference in mean for surgical time across the split. This process was repeated recursively on the resultant data. RESULTS: A total of 1709 RARPs were included. The variable most strongly associated with operative time was the surgeon (surgeons 2 and 4-102 minutes shorter than surgeons 1, 3, 5, and 6, p < 0.001). Among surgeons 2 and 4, BMI had the strongest association with surgical time (p < 0.001). Among patients operated by surgeons 1, 3, 5, and 6, RARP time was again most strongly associated with the surgeon performing RARP. Surgeons 1, 3, and 6 were on average 76 minutes faster than surgeon 5 (p < 0.001). The regression tree output in the form of box plots showed operative time median and ranges according to patient, disease, procedural, and surgeon metrics. CONCLUSION: We developed a methodology that can predict operative times for RARP based on patient, disease and surgeon variables. This methodology can be utilized for quality control, facilitate OR scheduling, and maximize OR efficiency.

Effects of osmolytes on stable UUCG tetraloops and their preference for a CG closing base pair.

Osmolytes have the potential to affect the stability of secondary structure motifs and alter preferences for conserved nucleic acid sequences in the cell. To contribute to the understanding of the in vivo function of RNA we observed the effects of different classes of osmolytes on the UNCG tetraloop motif. UNCG tetraloops are the most common and stable of the RNA tetraloops and are nucleation sites for RNA folding. They also have a significant thermodynamic preference for a CG closing base pair. The thermal denaturation of model hairpins containing UUCG loops was monitored using UV-Vis spectroscopy in the presence of osmolytes with different chemical properties. Interestingly, all of the osmolytes tested destabilized the hairpins, but all had little effect on the thermodynamic preference for a CG base pair, except for polyethylene glycol (PEG) 200. PEG 200 destabilized the loop with the CG closing base pair relative to the loop with a GC closing base pair. The destabilization was linear with increasing concentrations of PEG 200, and the slope of this relationship was not perturbed by changes in the hairpin stem outside of the closing pair. This result suggests that in the presence of PEG 200, the UUCG loop with a GC closing base pair may retain some preferential interactions with the cosolute that are lost in the presence of the CG closing base pair. These results reveal that relatively small structural changes may influence how osmolytes tune the stability, and thus the function of a secondary structure motif in vivo.