David C. Kerbl

Validation Study of a Virtual Reality Robotic Simulator—Role as an Assessment Tool?

PURPOSE Virtual reality simulators are often used for surgical skill training since they facilitate deliberate practice in a controlled, low stakes environment. However, to be considered for assessment purposes rigorous construct and criterion validity must be demonstrated. We performed face, content, construct and concurrent validity testing of the dV-Trainer™ robotic surgical simulator. MATERIALS AND METHODS Urology residents, fellows and attending surgeons were enrolled in this institutional review board approved study. After a brief introduction to the dV-Trainer each subject completed 3 repetitions each of 4 virtual reality tasks on it, including pegboard ring transfer, matchboard object transfer, needle threading of rings, and the ring and rail task. One week later subjects completed 4 similar tasks using the da Vinci® robot. Subjects were assessed on total task time and total errors using the built-in scoring algorithm and manual scoring for the dV-Trainer and the da Vinci robot, respectively. RESULTS Seven experienced and 13 novice robotic surgeons were included in the study. Experienced surgeons were defined by greater than 50 hours of clinical robotic console time. Of novice robotic surgeons 77% ranked the dV-Trainer as a realistic training platform and 71% of experienced robotic surgeons ranked it as useful for resident training. Experienced robotic surgeons outperformed novices in many dV-Trainer and da Vinci robot exercises, particularly in the number of errors. On pooled data analysis dV-Trainer total task time and total errors correlated with da Vinci robot total task time and total errors (p = 0.026 and 0.011, respectively). CONCLUSIONS This study confirms the face, content, construct and concurrent validity of the dV-Trainer, which may have a potential role as an assessment tool.

The da Vinci(®) Surgical System overcomes innate hand dominance.

BACKGROUND AND PURPOSE The robotic surgical platform has allowed for improved ergonomics, tremor filtration, and more precise surgical movements during minimally invasive surgery. We examined the impact of the da Vinci(®) Surgical System on the lateralization of manual dexterity, or handedness, innate to most surgeons. METHODS Manual dexterity assessments were conducted among 19 robotic novices using two different skills tests: The Purdue Pegboard Test and a needle targeting test. After an initial robotic basic skills training seminar, subjects underwent testing using both open and robotic approaches. Test performance using both approaches was then compared among all subjects. RESULTS The majority of subjects (84%) were right handed, and all subjects described their dominant hand as significantly or moderately more dexterous than their nondominant hand. The participants had significant differences between the dominant and nondominant hand in open skills tasks using the Purdue Pegboard test (15.4 vs 14.6 pegs, P=0.023) and needle targeting test (4.5 vs 3.7 targets, P=0.015). When the same tasks were performed using the robot, the differences in handedness were no longer observed (P=0.203, P=0.764). CONCLUSION The da Vinci robot is capable of eliminating innate dexterity or handedness among novice surgical trainees. This provides evidence of another beneficial aspect of robot-assisted surgery over traditional laparoscopic surgery and may facilitate operative performance of complex tasks.

Robotic Pyeloplasty: The University of California-Irvine Experience

PURPOSE For the treatment of ureteropelvic junction obstruction laparoscopic dismembered pyeloplasty and open pyeloplasty have similar outcomes. We present our experience with robot assisted laparoscopic dismembered pyeloplasty. MATERIALS AND METHODS We retrospectively reviewed all adult robot assisted laparoscopic dismembered pyeloplasties performed at our institution between November 2002 and July 2009. Preoperative evaluation included abdominal computerized tomography angiogram to assess for crossing vessels and diuretic renal scan to quantify the degree of obstruction. Followup with diuretic renal scan and a patient pain analog scale was performed 3, 6 and 12 months after surgery. If the study was normal at 12 months, the patient was followed with ultrasound of the kidneys and bladder to look for ureteral jets. Absent ureteral jets, worsening hydronephrosis or patient complaint of pain necessitated repeat diuretic renogram. RESULTS A total of 61 robot assisted laparoscopic dismembered pyeloplasties were performed in 21 men and 40 women. Followup was available for 57 patients with an average ± SD age of 35 ± 16 years and average followup of 18 ± 15 months. Mean operative time was 335 ± 88 minutes and estimated blood loss was 61 ± 48 ml. Average hospitalization time was 2 ± 0.9 days and the average postoperative analgesia requirement was 13 ± 9.6 mg morphine sulfate equivalents. The overall success rate was 81% based on a normal diuretic renogram and lack of pain using a validated pain scale. There were 3 grade III Clavien complications for a 4.9% major complication rate. CONCLUSIONS Robot assisted laparoscopic dismembered pyeloplasty is a feasible technique for ureteropelvic junction reconstruction. When measured by the more stringent application of diuretic renography and analog pain scales, the success rate for ureteropelvic junction obstruction management appears similar to that of open or standard laparoscopic approaches.

A History and Evolution of Laparoscopic Nephrectomy: Perspectives From the Past and Future Directions in the Surgical Management of Renal Tumors

June 25, 2010 marks the twentieth anniversary of the first clinical laparoscopic nephrectomy. Since the advent of this procedure a paradigm shift toward minimally invasive options for urological surgery has been witnessed, resulting in rapid technological innovations and improved patient outcomes. A history of the minimally invasive surgical management of renal masses is presented with a focus on laparoscopic nephrectomy.

Differences in Grip Forces Among Various Robotic Instruments and da Vinci Surgical Platforms

INTRODUCTION The da Vinci surgical platform is becoming increasingly available and utilized. Due to the lack of haptic feedback, visual cues are necessary to estimate grip forces and tissue tensions during surgery. We directly measured the grip forces of robotic EndoWrist instruments using the three available da Vinci robotic surgical platforms. METHODS Robotic instruments were tested in the da Vinci S, Si, and Standard systems. A load cell was placed in a housing unit that allowed for measurement of the grip forces applied by the tip of each robotic instrument. Each instrument was tested six times, and all data were analyzed using Students t-tests or analysis of variance when appropriate. RESULTS Slight differences in grip force were seen when the instrument was tested through 2 degrees of freedom at the tip (p = 0.02, analysis of variance) and when comparing a new instrument to an older instrument (p = 0.001 at the neutral position). There was no statistical difference in grip force between the left and right robotic arms. There was a broad range of grip forces between the various robotic instruments. The lowest grip force was registered in the double fenestrated grasper (2.26 ± 0.15 N), whereas the highest was seen in the Hem-o-lok clip applier (39.92 ± 0.89 N). In comparison to the S and Si, the Standard platform appeared to have significantly higher grip forces. CONCLUSION Different grip forces were observed among the various robotic instruments commonly used during urologic surgery and between the Standard and the S and Si platforms.

Aerosol transfer of bladder urothelial and smooth muscle cells onto demucosalized colonic segments for bladder augmentation: in vivo, long term, and functional pilot study.

BACKGROUND Bladder augmentation technique has changed over the years and the current practice has significant adverse health effects and long-term sequelae. Previously, we reported a novel cell transfer technology for covering demucosalized colonic segments with bladder urothelium and smooth muscle cells through an aerosol spraying of these cells and a fibrin glue mixture. OBJECTIVE To determine the long-term durability and functional characteristics of demucosalized segments of colon repopulated with urothelial cells in the bladder of swine for use in augmentation cystoplasty. STUDY DESIGN Nine swine were divided into three groups. The first group (control) underwent standard colocystoplasty; the second group underwent colocystoplasty with colonic demucosalization and aerosol application of fibrin glue and urothelial cell mixture; in the third group detrusor cells were added to the mixture described in group two. The animals were kept for 6 months. Absorptive and secretory function was assessed. Bladders were harvested for histological and immunohistochemical evaluation. RESULTS All animals but one in the experimental groups showed confluent urothelial coverage of the colonic segment in the bladder without any evidence of fibrosis, inflammation, or regrowth of colonic epithelial cells. Ten percent of the instilled water in the bladder was absorbed within an hour in the control group, but none in experimental groups(p = 0.02). The total urine sediment and protein contents were higher in the control group compared with experimental groups (p < 0.05). DISCUSSION Both study groups developed a uniform urothelial lining. Histologically, the group with smooth muscle had an added layer of submucosal smooth muscle. Six months after bladder augmentation the new lining was durable. We were also able to demonstrate that the reconstituted augmented segments secrete and absorb significantly less than the control colocystoplasty group. We used a non-validated simple method to evaluate permeability of the new urothelial lining to water. To determine if the aerosol transfer of bladder cells would have behaved differently in the neurogenic bladder population, this experiment should have been performed in animals with neuropathic bladders. CONCLUSION Aerosol spraying of single cell suspension of urothelial and muscular cells with fibrin glue resulted in coverage of the demucosalized intestinal segment with a uniform urothelial layer. This new lining segment was durable without regrowth of colonic mucosa after 6 months. The new reconstituted segment absorbs and secretes significantly less than control colocystoplasty.