Joseph A. Graversen

Validation, Correlation, and Comparison of the da Vinci Trainer™ and the da Vinci Surgical Skills Simulator™ Using the Mimic™ Software for Urologic Robotic Surgical Education

PURPOSE Virtual reality simulators with self-assessment software may assist novice robotic surgeons to augment direct proctoring in robotic surgical skill acquisition. We compare and correlate the da Vinci Trainer™ (dVT) and da Vinci Surgical Skills Simulators (dVSSS) in subjects with varying robotic experience. MATERIALS AND METHODS Students, urology residents, fellows, and practicing urologists with varying robotic experience were enrolled after local institutional review board approval. Three virtual reality tasks were preformed in sequential order (pegboard 1, pegboard 2, and tubes)-initially on the dVSSS and then on the dVT. The Mimic™ software used on both systems provides raw values and percent scores that were used in statistical evaluation. Statistical analysis was performed with the two-tailed independent t-test, analysis of variance, Tukey, and the Pearson rank correlation coefficient where appropriate. RESULTS Thirty-two participants were recruited for this study and separated into five groups based on robotic surgery experience. In regards to construct validity, both simulators were able to differentiate differences among the five robotic surgery experience groups in the tubes suturing task (p≤0.00). Sixty-seven percent (4/6) robotic experts thought that surgical simulation should be implemented in residency training. The overall cohort considered both platforms easy to learn and use. CONCLUSIONS Although performance scores were less in the dVT compared with the dVSSS, both simulators demonstrate good content and construct validity. The simulators appear to be equivalent for assessing surgeon proficiency and either can be used for robotic skills training with self-assessment feedback.

Post-Percutaneous Nephrolithotomy Systemic Inflammatory Response: A Prospective Analysis of Preoperative Urine, Renal Pelvic Urine and Stone Cultures

PURPOSE Prior studies suggest that renal pelvic urine culture is a more accurate predictor of urosepsis. We prospectively determined the correlation between preoperative bladder urine cultures, intraoperative renal pelvis cultures and stone cultures in patients undergoing percutaneous nephrolithotomy. We also examined post-procedure risk factors for systemic inflammatory response syndrome. MATERIALS AND METHODS From February 2009 to February 2011 urine samples from the bladder and renal pelvis were collected from patients undergoing percutaneous nephrolithotomy. Extracted stones were also sent for culture analysis. Postoperatively patients were closely monitored for any signs of systemic inflammatory response syndrome. The concordance of urine and stone cultures across different sites was examined. Regression analysis was done to identify clinical variables associated with systemic inflammatory response syndrome. RESULTS A total of 204 percutaneous nephrolithotomies were done in 198 patients, of whom 20 (9.8%) had evidence of systemic inflammatory response syndrome postoperatively, including 6 (30%) requiring intensive care. The concordance among stone, renal pelvic and preoperative cultures was 64% to 75% with the highest concordance between renal pelvic urine and stone cultures. In a multivariate model multiple access tracts and a stone burden of 10 cm(2) or greater were significant predictors of systemic inflammatory response syndrome postoperatively. CONCLUSIONS Even appropriately treated preoperative urinary infections may not prevent infected urine at percutaneous nephrolithotomy. Renal pelvic urine and stone cultures may be the only way to identify the causative organism and direct antimicrobial therapy. We recommend collecting pelvic urine and stone cultures to identify the offending organism in patients at risk for sepsis, particularly those with a large stone burden requiring multiple access tracts.

Validating the Use of the Mimic dV-trainer for Robotic Surgery Skill Acquisition Among Urology Residents

OBJECTIVE To compare robotic surgery skill acquisition of residents trained with Mimic dVTrainer (MdVT) and da Vinci Surgical System (dVSS) console. No standardized curriculum currently exists for robotic surgical education. The MdVT is a compact hardware platform that closely reproduces the experience of the dVSS. METHODS Sixteen urology trainees were randomized into 3 groups. A baseline evaluation using dVSS was performed and consisted of 2 exercises requiring endowrist manipulation (EM), camera movement and clutching (CC), needle control (NC), and knot-tying (KT). Groups 1 and 2 completed a standardized training curriculum on MdVT and dVSS, respectively. Group 3 received no additional training. After completion of the training phase, all trainees completed a secondary evaluation on dVSS consisting of the same exercises performed during baseline evaluation. RESULTS There was no difference in baseline performance scores across the 3 groups. Although Group 3 showed no significant improvement in EM/CC domain (P = .15), Groups 1 and 2 had statistically significant improvement in EM/CC domain (P = .039 and P = .007, respectively). The difference in improvement between Groups 1 and group 2 was not statistically different (P = .21). Only Group 2 trainees showed significant improvement in the NC and KT domains during secondary evaluation (P = .02). CONCLUSION Curriculum-based training with MdVT or dVSS significantly improves robotic surgery aptitude. Similar improvements are seen for exercise domains shared between MdVT and dVSS groups. Follow-up studies are necessary to assess the efficacy of MdVT over a wider spectrum of domains.

Polyglyconate unidirectional barbed suture for posterior reconstruction and anastomosis during robot-assisted prostatectomy: effect on procedure time, efficacy, and minimum 6-month follow-up.

BACKGROUND AND PURPOSE With widespread implementation of posterior rhabdosphincter reconstruction (RSR) followed by urethrovesical anastomosis (UVA), reconstruction has become a significant portion of robot-assisted laparoscopic prostatectomy (RALP). Successful anastomosis can be measured by time for reconstruction and the absence of urinary leak. We prospectively evaluated the experience of a single surgeon (KKB) in using the V-Loc™ wound closure device for the posterior RSR and UVA, and compared it with a standard reconstruction and anastomosis. PATIENTS AND METHODS A total of 84 patients divided into two groups underwent RALP, undergoing RSR and UVA using a Van Velthoven technique with the V-Loc or with a standard 3-0 monofilament suture. The primary end point was the time to complete RSR, UVA, and the total reconstruction. As a secondary end point, the clinical evidence of an anastomotic leak was also documented. RESULTS The mean RSR, UVA, and total times were 9, 18, and 27 minutes for the control group, and 6, 12 and 18 minutes for the V-Loc group, respectively. The time differences between the two groups for RSR, UVA, and total time were 3 minutes (P<0.01), 6 minutes (P<0.01), and 9 minutes (P<0.001), respectively. There was no clinical evidence of anastomotic leak in either group. Continence recovery was equivalent between the groups at 6 weeks and 6 months. At a 9-month follow-up, no patients in either group had a clinical UVA stricture necessitating intervention. CONCLUSIONS The V-Loc suture is associated with a significantly shorter time for the RSR and UVA compared with the traditional suture and is not associated with a higher incidence of clinical urinary leak; however, a larger randomized study with long-term follow-up is necessary to confirm these results.

Clinical, Pathologic, and Functional Outcomes After Nephron-Sparing Surgery in Patients with a Solitary Kidney: A Multicenter Experience

BACKGROUND AND PURPOSE Surgical management of a renal neoplasm in a solitary kidney is a balance between oncologic control and preservation of renal function. We analyzed patients with a renal mass in a solitary kidney undergoing nephron-sparing procedures to determine perioperative, oncologic, and renal functional outcomes. PATIENTS AND METHODS A multicenter study was performed from 12 institutions. All patients with a functional or anatomic solitary kidney who underwent nephron-sparing surgery for one or more renal masses were included. Tumor size, complications, and recurrence rates were recorded. Renal function was assessed with serum creatinine level and estimated glomerular filtration rate. RESULTS Ninety-eight patients underwent 105 ablations, and 100 patients underwent partial nephrectomy (PN). Preoperative estimated glomerular filtration rate (eGFR) was similar between the groups. Tumors managed with PN were significantly larger than those managed with ablation (P<0.001). Ablations were associated with a lower overall complication rate (9.5% vs 24%, P=0.01) and higher local recurrence rate (6.7% vs 3%, P=0.04). Eighty-four patients had a preoperative eGFR ≥60 mL/min/1.73 m(2). Among these patients, 19 (23%) fell below this threshold after 3 months and 15 (18%) at 12 months. Postoperatively, there was no significant difference in eGFR between the groups. CONCLUSIONS Extirpation and ablation are both reasonable options for treatment. Ablation is more minimally invasive, albeit with higher recurrence rates compared with PN. Postoperative renal function is similar in both groups and is not affected by surgical approach.

Retrospective Comparison of Laparoscopic Partial Nephrectomy Versus Laparoscopic Renal Cryoablation for Small (<3.5 cm) Cortical Renal Masses

OBJECTIVE We compared perioperative and short-term outcomes of renal laparoscopic partial nephrectomy (LPN) and laparoscopic cryoablation (LCA) in patients with small (<3.5 cm) renal cortical neoplasms. METHODS A retrospective analysis from our prospectively established database was performed. We identified 92 patients with 95 lesions treated with LPN and 75 patients with 91 lesions treated with LCA. RESULTS The LPN and LCA groups were comparable in mean tumor size and preoperative and postoperative creatinine level (P=.495, P=.953, and P=.101) respectively. Patients undergoing LPN were younger in age (58.8 versus 69.2 years, P<.001), had a higher mean estimated blood loss (168.4 versus 6  mL, P=.005), and had a prolonged mean operative time (151.6 versus 128.6 minutes, P=.01). Six complications occurred in the LCA group and 11 in the LPN group. The median follow-up time was 21.8 months for LPN and 14 months for LCA (P<.001). Two recurrences were detected in the LCA group, and 1 recurrence was reported after LPN. CONCLUSIONS In the treatment of small renal cortical neoplasms with short-term follow-up, LPN and LCA seem to be equally effective. LCA offers decreased blood loss, shorter operative time, and less morbidity. Longer follow-up is required to establish oncologic efficacy.

Tracking and assessment of technical skills acquisition among urology residents for open, laparoscopic, and robotic skills over 4 years: is there a trend?

BACKGROUND AND PURPOSE Tracking the progression of technical skill acquisition during urology residency training is an essential yet challenging task that has been mostly based on anecdotal and subjective performance assessment. We evaluated five surgical tasks used at our institution to assess skill acquisition among residents over 4 consecutive years in an effort to determine appropriate skill testing for resident proficiency relative to level of training for future performance testing. METHODS Urology residents were tested yearly throughout the course of their residency with five surgical tasks in an open, laparoscopic, and robotic format. The five tasks were: (1) rings on a peg, (2) thread the rings, (3) cut the line, (4) hexagonal suturing, and (5) suture and knot tying. Evaluation was performed by a trained instructor to assess quantity and quality of the skill task performance. RESULTS The highest scores were obtained on all open tasks regardless of training level. Residents performed second best on robotic and lowest on the laparoscopic skill tasks. The score difference among surgery platforms was statistically significant P<0.0005 across all tasks. It was Tasks 2 and 5, however, that showed a statistically significant difference in overall quantity×quality score between different postgraduate year (PGY) residents (P=0.03 and P=0.02). In addition, the quantity score for Task 5 also showed a statistically significant difference among PGY residents (P=0.04). There was no statistically significant difference in time to perform tasks among PG years. CONCLUSIONS The high-level Tasks 2 and 5 were the most useful in differentiating different levels of skill task competency among urology residents and appear to be most useful in assessing the degree of improvement among residents during training. These tasks have subsequently been worked into our institutions testing curriculum.

Evaluation of Bioimpedance as Novel Predictor of Extracorporeal Shockwave Lithotripsy Success

BACKGROUND AND PURPOSE Obesity has been identified as a limitation of extracorporeal shockwave lithotripsy (SWL). The obesity metrics of body mass index (BMI) and skin-to-stone distance (SSD) have been evaluated as predictors of SWL success. While SSD has demonstrated a strong correlation with success, BMI has not. Bioimpedance analysis (BIA) is an accurate way of determining body adiposity. We evaluated fat mass percentage (FMP) as measured by BIA as a predictor of SWL success. PATIENTS AND METHODS We prospectively collected body composition data using the Imp-DF50 Body Impedance Analyzer on consecutive patients undergoing SWL. All generated variables, including FMP, along with demographics, BMI, stone size, and stone composition, were analyzed. Patients were evaluated for success, defined as no evidence of stones on radiography of the kidneys, ureters, and bladder at follow-up. RESULTS Fifty-two consecutive patients were enrolled in the study, of which 37 had the necessary metrics to be included in the analysis. Twenty-three (62.2%) patients were stone free while 14 (37.8%) were found to have residual stone at follow-up. There was no difference in sex, stone laterality, mean age, and stone size between the groups. For the success and failure groups, the mean BMI was 25.8 kg/m(2) and 29.8 kg/m(2) (P=0.0091), and mean FMP 24.6% and 32.2% (P=0.0034). On mirrored multivariable analysis, both BMI (OR=0.735, P=0.026) and FMP (OR=0.806, P=0.010) were associated with success. Patients with a FMP ≥35% had a reduced success rate compared with those with a FMP <35% (14% vs 73%, respectively, P=0.0028). CONCLUSIONS Both BMI and FMP both appear to be independent predictors of success. Based on these findings, a large study examining the relationship between BMI, FMP, SSD, and SWL success is warranted. A preoperative FMP ≥35% is associated with a 14% success rate, and alternative treatment strategies for urolithiasis should be considered.

Laparoscopic Ablation of Renal Neoplasms

As a result of the widespread application of cross sectional imaging, there has been a significant rise in the incidence of small renal cortical neoplasms. The current standard of care in the management of these lesions is nephron-sparing extirpative surgery. In the last decade, however, image-guided or ablative therapies have garnered significant attention as nephron-sparing alternatives to partial nephrectomy. Although initially laparoscopic ablation was predominately intended for use as active treatment in those patients in whom more invasive therapy was contraindicated, as experience with laparoscopic ablation has become more robust, the indications for the procedure continue to evolve. The current article reviews the indications and contraindications, preoperative preparation, surgical technique, and postoperative follow-up for laparoscopic ablative procedures. Also discussed are techniques and patient selection criteria to avoid complications, as well as the management of complications that do occur.

Genitourinary Exam Skills Training Curriculum for Medical Students: A Follow-up Study of Comfort and Skill Utilization

PURPOSE We developed a genitourinary skills training (GUST) curriculum for incoming third year medical students (MS3) and performed a follow-up study of comfort with and utilization of these skills. MATERIALS AND METHODS GUST consisted of a didactic lecture followed by skills sessions including standardized patient testicular examination (TE) and digital rectal examination (DRE), male and female Foley catheter (MFC and FFC) placement training, suture-knot tying, and a faculty-directed small group learning session. Precourse and postcourse, and 6 and 18 months after the course, MS3 rated comfort with each skill (Likert scale 0-5), and quantified skill usage. Results were compared with 4th year students (MS4) who had not undergone GUST. RESULTS Participants were 281 MS3 GUST students and 44 MS4. Post-GUST, mean comfort on a Likert scale (0=uncomfortable) increased for all four skills (88.2%-96.9% vs 8.3%-18.5%, P<0.0001). This was maintained at the 6-month and 18-month follow up time points (P<0.0001). At 18 months, MS3 trended toward higher comfort with TE compared with MS4 (74 vs 54%, P=0.068), while with the other skills, both groups showed equal comfort. MS4 learned exam skills from faculty and MFC and FFC from nurses on the wards. Eleven percent of MS4 were never formally taught TE or DRE. MS3 and MS4 performed TE and/or DRE on <8% of newly admitted patients. CONCLUSIONS MS3 described improved comfort with the GU skills at all time points during follow-up. This was particularly important because both MS3 and MS4 reported using their skills infrequently during their clinical training years.