Predictors of postoperative decline in estimated glomerular filtration rate in patients undergoing robotic partial nephrectomy.

PURPOSE: To identify prognostic indicators of estimated glomerular filtration rate (eGFR) following robotic partial nephrectomy (RPN). MATERIALS AND METHODS: In a retrospective study of RPN patients, we examined data describing age, gender, eGFR, body mass index (BMI), tumor size (TS), length of stay, and estimated blood loss (EBL). Changes in eGFR (i.e., renal function trajectory [RFT]) and chronic kidney disease (CKD) stage shift were analyzed with mixed model linear and logistic regression analyses, Chi-squared, and t-tests. RESULTS: Changes in eGFR (RFT) were determined in 122 patients at baseline and at 6- and 12-month follow-up visits. Mean age, TS, and Charlson comorbidity index (CCI) were 62±11 years, 3±1.2 cm, and 4.8±1.8, respectively. The pre- and postoperative eGFR was lower in patients >60 years. Preoperative eGFR was unrelated to gender, BMI>30 kg/m(2), histopathology, nuclear grade, and TS. Univariate analyses determined that age, BMI>30, EBL>200 mL, CCI>5, and TS were associated with greater declines in eGFR. Reduced eGFR was also associated with warm ischemia time ≥22 minutes, while age was associated with a ≥1 worsening of British CKD classification. Using multivariate analysis, only age was significantly associated with a decline in eGFR, which was greater in patients with a normal preoperative eGFR. CONCLUSIONS: Patient age, BMI>30, EBL>200 mL, CCI>5, and TS were predictors of greater postoperative declines in eGFR. Although a decline in eGFR was proportionally greater in low stage CKD, postoperative changes are associated with advancing age.

Was a Change to a Urologist Owned Pathology Laboratory Associated with a Change in Prostate Biopsy Use?

INTRODUCTION: We assessed the impact of self-referral to urologist owned pathology facilities on prostate biopsy practice patterns, clinical decision making and pathology service use. METHODS: We reviewed a transrectal ultrasound guided prostate biopsy database during 2 periods, including 1) August 5, 2008 to April 10, 2010 (613 days) when pathology samples were sent to an independent service laboratory, and 2) June 11, 2010 to February 13, 2012 (613 days) when samples were assessed at a urologist owned pathology laboratory. We also examined data on 3 additional preceding equal length periods before urologist ownership to determine baseline biopsy rates. Billing databases were used to identify the number of new patient visits for increased prostate specific antigen and/or abnormal digital rectal examination. The Student t-test, and Wilcoxon rank sum and chi-square tests were used for statistical comparisons. RESULTS: All biopsies were obtained using a standard transrectal ultrasound guided prostate biopsy protocol. The biopsy rate in patients with increased or abnormal digital rectal examination was 39% during the urologist owned pathology laboratory era, and 35%, 40%, 35% and 40% during the 4 preceding independent service laboratory periods of equal length. There was no statistically significant difference in patient age, rate of abnormal digital rectal examination or indications for repeat transrectal ultrasound guided prostate biopsy among the periods. The prostate cancer detection rate was 45% in the independent service laboratory era and 46% in the urologist owned pathology laboratory era. CONCLUSIONS: Self-referral of transrectal ultrasound guided prostate biopsy specimens to urologist owned pathology facilities was not associated with a significant variation in the biopsy rate, the repeat biopsy rate, indications triggering repeat biopsy or the cancer detection rate.

Can visuospatial ability predict performance and learning curves on a robotic surgery simulator?

OBJECTIVE: This study aimed to examine the correlation between visuospatial ability, measured with the Perceptual Ability Test (PAT), and da Vinci robot simulator performance on the da Vinci Skills Simulator. METHODS: Twenty-five consenting medical students naive to both the PAT and the da Vinci robot completed the PAT and then performed a single simulation (Ring-walk 2) 10 consecutive times. Raw PAT scores were compared with composite simulator scores for all subjects. Participants were divided into those with high and low visuospatial ability based on whether they scored above or below (or equal) to the median on the PAT. We compared the mean composite simulator scores and the time to complete each exercise between the high and the low PAT performers. RESULTS: The mean (SD) raw PAT score (out of 90) was 45.5 (18.3) (median, 43.0). The mean composite simulator score was 65.5 (24.1) (median, 72.2). The high (n = 12) and low (n = 13) PAT performers had a mean (SD) (median) simulator score of 79.1 (9.8) (80.3) and 53.0 (26.7) (65.9), respectively. On average, the high PAT performers scored 26.1 points (95% confidence interval, 9.2-43.0, P = 0.005), or 49.2%, higher on the simulation than the low PAT performers. The high PAT performers completed the exercise in 96.5 seconds (95% confidence interval, 26.0-167.0; P = 0.009), or 36.2%, faster than the low PAT performers. CONCLUSIONS: Better visuospatial ability relates to improved performance on a robotic surgery simulator.

The impact of body mass index on perioperative outcomes in robot-assisted laparoscopic partial nephrectomy.

BACKGROUND AND PURPOSE: Obese patients undergoing surgical procedures are at increased risk for perioperative morbidity. The purpose of this study is to determine whether there is an association with body mass index (BMI), clinicopathologic features, and perioperative outcomes and complications in patients undergoing robot-assisted laparoscopic partial nephrectomy (RPN). PATIENTS AND METHODS: Medical records of 283 patients who underwent RPN between 2007 and 2012 were reviewed from an Institutional Review Board approved database. We analyzed the association of perioperative outcomes and complications of the surgery with BMI and clinicopathologic features using analysis of variance, Kruskal-Wallis test, t test and chi-square-test. Eventually, independent factors associated with perioperative outcomes and complications were studied using univariate and multivariate regression analysis. RESULTS: Perioperative outcomes including estimated blood loss (EBL), length of hospital stay (LOS) and operative time (OT) were significantly associated with BMI (P=0.002, P=0.009 and P=0.002, respectively). Warm ischemia time (WIT), perioperative complications, and change in glomerular filtration rate (GFR) before and after surgery were not associated with BMI (P=0.459, P=0.86 and P=0.773). In multivariate analysis, BMI, tumor size≥4 cm, and collecting system invasion were independently associated with EBL and OT. Increased LOS was independently associated with BMI and tumor size ≥4 cm. CONCLUSIONS: Increasing BMI was not associated with a significant increase in perioperative complications, WIT, or change in GFR in patients undergoing RPN at a high-volume tertiary medical center. Collecting system invasion or tumor size ≥4 cm and BMI were independently associated with higher EBL, LOS, and OT, however.

The feasibility of screening for violence in the pediatric emergency department.

BACKGROUND: Youth violence is a significant public health concern. The objective of this study was to evaluate the feasibility of violence screening tools in a pediatric emergency department (PED). METHODS: Children between eight and 17 years presenting to the PED were prospectively enrolled. Two questionnaires were administered: Violence Prevention Emergency Tool (VPET) and Violence Exposure Scale for Children (VEX). RESULTS: One hundred children were enrolled: mean age was 12.9 years (SD 2.8), 42% girls, 48% Hispanic, and 13% African-American. Mean time to complete VPET was 9.0 minutes and VEX 4.9 minutes. Ease of understanding between VPET and VEX were 74% vs 92% (interviewer) and 74% vs 93%, (subjects) both P < 0.05. The number of repeated items was significantly less for VEX compared to VPET, 1% vs 6% (P < 0.01). CONCLUSION: It may be feasible to screen for exposure to violence in the PED. VEX is a more feasible screening tool compared to VPET.

da Vinci Skills Simulator construct validation study: correlation of prior robotic experience with overall score and time score simulator performance.

OBJECTIVE: To assess the construct validity of the da Vinci Skills Simulator (Intuitive Surgical, Sunnyvale, CA). Ideally, a well-designed simulator should demonstrate construct validity, which is defined in this study as the correlation between robotic surgical experience and performance on the simulator. PATIENTS AND METHODS: Thirty-nine surgeons (18 [46%] group I [0-20 robotic cases]; 8 [21%] group II [21-150 robotic cases]; and 13 [33%] group III [>150 robotic cases]) were enrolled from September 2010 to December 2010. Participants completed 24 virtual-reality exercises on the da Vinci Skills Simulator. Data on 12 performance metrics were collected by the software. Overall means for score and time across exercises were analyzed. RESULTS: Overall scores (64.7%/79.1%/87.4%) and time scores (39.1%/58.6%/87.3%) were significantly different among surgeons in groups I-III (P <.001) and demonstrated significant linear relationships (P <.001) for all 24 exercises. Comparisons between the 3 groups using a univariate general linear model (GLM) was used to compare groups I and II and II and III. Groups I and II differed using overall score for 15 exercises and time score for 11 exercises. Groups II and III differed using overall score for 6 exercises and time score for 15 exercises. Mean overall score for 1 exercise displayed significance between both groups I and II and II and III; while using time score, 5 exercises displayed significance between surgeons in groups I and II and II and III. CONCLUSION: Initial construct validity analysis revealed that both overall scores and time scores showed a significant linear relationship when comparing the surgeons in groups I, II, and III. Overall score seems to be a stronger indicator for differences between surgeons in groups I and II. Time score seems to be a stronger indicator for differences between surgeons in groups II and III.