Ryan Pickens

Design and Performance Evaluation of a Minimally Invasive Telerobotic Platform for Transurethral Surveillance and Intervention

Bladder cancer, a significant cause of morbidity and mortality worldwide, presents a unique opportunity for aggressive treatment due to the ease of transurethral accessibility. While the location affords advantages, transurethral resection of bladder tumors can pose a difficult challenge for surgeons encumbered by current instrumentation or difficult anatomic tumor locations. This paper presents the design and evaluation of a telerobotic system for transurethral surveillance and surgical intervention. The implementation seeks to improve current procedures and enable development of new surgical techniques by providing a platform for intravesicular dexterity and integration of novel imaging and interventional instrumentation. The system includes a dexterous continuum robot with access channels for the parallel deployment of multiple visualization and surgical instruments. This paper first presents the clinical conditions imposed by transurethral access and the limitations of the current state-of-the-art instrumentation. Motivated by the clinical requirements, the design considerations for this system are discussed and the prototype system is presented. Telemanipulation evaluation demonstrates submillimetric RMS positioning accuracy and intravesicular dexterity suitable for improving transurethral surveillance and intervention.

Single incision mid-urethral sling for treatment of female stress urinary incontinence.

OBJECTIVES To present the longitudinal outcomes in an observational cohort of patients who had undergone treatment of stress urinary incontinence with a single incision mid-urethral sling (MUS). METHODS A prospective, observational study of all female patients who had undergone surgical intervention with the MiniArc MUS was performed. The surgical candidates underwent history and physical examination and urodynamic testing, as indicated. Quality of life questionnaires (Urogenital Distress Inventory [UDI-6] and Incontinence Impact Questionnaire [IIQ-7]) were administered preoperatively. The salient operative data were recorded. The patients were followed up postoperatively for evidence of treatment success and adverse events. The patients completed the UDI-6, IIQ-7, and Female Sexual Function Index questionnaires at 1 and 12 months after treatment. RESULTS From September 2007 to October 2008, 120 patients underwent placement of the MiniArc MUS for the treatment of stress urinary incontinence. The mean patient age was 58.4 years. The mean body mass index was 27.2 kg/m(2). The mean preoperative daily pad use was 2.4. The mean preoperative IIQ-7 and UDI-6 score was 86.58 and 62.5, respectively. Of the 120 patients, 108 (90%) completed a minimum follow-up period of 12 months. Of these 108 patients, 101 (94%) were cured/dry. The mean postoperative pad use was 0.2 (P < .001). The mean IIQ-7 and UDI-6 score was 13.32 (P < .001) and 12.5 (P < .001), respectively. The Female Sexual Function Index results demonstrated no discomfort with intercourse in 49%, occasional discomfort in 9%, and frequent discomfort in 2%. The remaining 40% of our patients were not sexually active. CONCLUSIONS Our results have shown that the MiniArc MUS offers excellent outcomes that are durable at 1 year after treatment.

A Pilot Ex-Vivo Evaluation of a Telerobotic System for Transurethral Intervention and Surveillance

INTRODUCTION Transurethral resection of bladder tumor (TURBT) and pathological staging are both standard surgical therapies for nonmuscle-invasive bladder cancer and integral parts of the diagnostic evaluation and progression monitoring of all bladder tumors. We developed and tested a dexterous robot that can fit through a standard resectoscope for evaluation for possible en bloc resection of bladder tumors, especially tumors along the dome and anterior wall of the bladder. MATERIALS AND METHODS Our dexterous robot uses a continuum (snake-like) mechanical architecture with three working channels through which a fiberscope, biopsy graspers, and a holmium laser were placed. The continuum robot has two segments. Using indigo carmine, injections were performed through the detrusor muscle into the mucosa of the ex vivo bovine bladders at a total of 11 positions throughout all quadrants of the bladder. The snake robot was used in conjunction with the holmium laser to ablate nine of the lesions; two additional lesions were resected en bloc using the grasper and the laser down through the muscle layer. RESULTS Both experiments showed that the robotic system was able to directly visualize all 11 targets. In both the bladders, we were able to resect en bloc two tumors using the grasper and 200 μm holmium laser fiber down to the muscle layer indicating a good resection. All of the other targets were completely ablated using the holmium laser. CONCLUSION The dexterous robot allowed for visualization as well as provided adequate ablation and en bloc resection of bladder lesions throughout the entire bladder.

Constrained motion control of multisegment continuum robots for transurethral bladder resection and surveillance

Constrained motion control of robotic end-effectors is essential for safe operation in confined spaces such as the urinary bladder. This paper presents the clinical motivation for the development of new control algorithms for robotic-assisted transurethral bladder resection and surveillance using multisegment continuum robots. The anatomy, workspace, and access constraints for this procedure are identified and used as a guideline for the design of the telesurgical system and its control architecture. Constraints are mapped into the configuration space of the robot rather than in task space simplifying the modeling and the enforcement of virtual fixtures. The redundancy resolution is autonomously modified in order to exploit the remaining degrees of freedom using task priority. These methods are validated on a glass model of urinary bladder.

Fine Tilt Tuning of a Laparoscopic Camera by Local Magnetic Actuation: Two-Port Nephrectomy Experience on Human Cadavers

Background. The magnetic surgical camera is an emerging technology having the potential to improve visualization without taking up port site space. However, tilting the point of view downward/upward can be done only by constantly applying a pressure on the abdomen. This study aims to test the hypothesis that the novel concept of local magnetic actuation (LMA) is able to increase the tilt range available for a magnetic camera without the need for deforming the abdominal wall. The hypothesis that 2-port laparoscopic nephrectomy in fresh tissue human cadavers could be performed by using the LMA camera is also tested. Methods. First, the 2 cameras were separately inserted, anchored, and moved inside the inflated abdomen. Tilting angles were quantified by image analysis while intra-abdominal pressure changes were monitored. Then, 5 two-port nephrectomies were performed by using the LMA camera while collecting quantitative outcomes. Results. The magnetic camera required a constant pressure on the magnetic handle to achieve an average ±20° tilt from the horizontal position, with an average of 7 mm Hg loss of intra-abdominal pressure. The LMA camera allowed for 75° of tilt from the horizontal position with a resolution of ±1°, without any need to deform the abdomen. All the nephrectomies were completed successfully within an average time of 11 minutes. Conclusion. LMA is an effective strategy to provide magnetic cameras with wide-range and high-resolution vertical motion without the need to deform the abdominal wall.

Adequate or Not? A Comparison of 24-Hour Urine Studies for Renal Stone Prevention by Creatinine to Weight Ratio

PURPOSE The intent of this study was to compare urine parameters between kidney stone formers with low, expected, and high creatinine to weight ratio (Cr/kg) and to discuss implications for treatment. PATIENTS AND METHODS In this retrospective study, 381 stone formers (205 females and 176 males) with urine collections for nephrolithiasis evaluation were included. Using the first collected sample, patients were grouped into low, expected, and high Cr/kg using sex appropriate reference ranges (15.0-20.0 mg/kg for females and 18.0-24.0 mg/kg for males) and evaluated. RESULTS Of initial collections, 50.7% were outside the Cr/kg reference range. Median age increased as Cr/kg decreased with 13 years age difference between low (56) and high (43) groups. Body mass index and weight also increased significantly with decreased ratio. No significant difference between groups was found for urine volume, total oxalate, oxalate concentration, pH, and supersaturations of calcium oxalate and uric acid. Total calcium, sodium, citrate, calcium concentration, supersaturation of calcium phosphate, and other parameters significantly increased with increased Cr/kg for the cohort. CONCLUSIONS To our knowledge, this is the first study to thoroughly evaluate the impact of Cr/kg on urine parameters. Clinicians should be cognizant of limitations of Cr/kg for evaluating collection adequacy. It is especially important to consider Cr/kg when there is potential for undertreatment or overtreatment of patients with abnormal Cr/kg. Studies demonstrating hypercalciuria and high Cr/kg may need to be repeated before starting thiazide diuretics. Further studies are needed to determine how to better interpret urine components that vary with Cr/kg ratio.

PD30-07 OUTPATIENT TUBELESS MINI-PCNL FOR MODERATE TO LARGE RENAL STONES: OUR ONGOING EXPERIENCE

INTRODUCTION AND OBJECTIVES: Percutaneous nephrolithotomy (PCNL) for the treatment of renal calculi has traditionally been an inpatient procedure often requiring a multi-day hospitalization. Large-bore nephrostomy tubes and ureteral stents have also been traditionally placed for control of bleeding and urinary drainage. Currently, more advanced technology as well as smaller operating nephroscopes and lithotripters have made PCNL a less morbid procedure with the possibility of being done on an outpatient basis. Our aim is to show that mini-PCNL can be safely performed in a tubeless fashion on an outpatient basis. METHODS: We performed a retrospective chart review of patients that underwent mini-PCNL at our institution by a single fellowshiptrained endourologist. Only those patients who were discharged home the same day without nephrostomy tubes or ureteral stents were included. Cases were performed using mini-nephroscopes with an outer diameter of 15 to 17.5-Fr. RESULTS: There were 15 patients included for analysis. Average age was 51.3 years. The group was 53% female and 47% male. Mean BMI and ASA score were 29.31 and 2.4, respectively. Total operative time averaged 55.6 minutes [range 27 106]. Mean estimated blood loss was 12.87-mL [range 3-30-mL]. Stone size ranged from 1.3cm to 3-cm. Left and right sided stones were split evenly. There were multiple stones in 47% of patients. Primary stone location varied, but the majority were in the renal pelvis or the lower pole. Renal access was obtained in a middle or interpolar calyx 53% of the time, and 47% in the lower pole. Laser or ultrasonic lithotripsy was utilized. FLOSEAL was administered in the tract, and no stents or nephrostomy tubes were left. All patients were discharged home. No patients were readmitted or had unplanned ER visits so far. All patients with follow-up were stone free on KUB and RUS imaging. CONCLUSIONS: Mini-PCNL using operating nephroscopes up to 17.5-Fr can be safely performed on an outpatient basis in a tubeless fashion without nephrostomy tubes or ureteral stents. Some of our patients went home with Foley catheters that were removed the following morning. With the advent of improved optics and smaller ultrasonic lithotripters, mini-PCNL is a worthwhile option for patients with renal calculi that can be accomplished safely in a cost-saving outpatient basis, all while rendering patients stone free with one procedure. With changes in reimbursement for hospitals and physicians in the future, outpatient mini-PCNL could serve as a sound option for those with moderate to large renal stones who wish to be rendered stone free in one operation and avoid ureteral stents.

PD66-10 BULB SUCTION DRAINAGE IS NOT NECESSARY AFTER ROUTINE ROBOTIC-ASSISTED PARTIAL NEPHRECTOMY: A LARGE CASE-CONTROL ANALYSIS

INTRODUCTION AND OBJECTIVES: Partial nephrectomy is widely utilized for surgical management of small renal masses. Robotic partial nephrectomy (RPN) has demonstrated improved postoperative morbidity and comparable oncologic outcomes compared to open partial nephrectomy (OPN). However, there is limited data regarding the utilization of RPN across different socio-economic strata and racial groups in the United States. We investigated trends and disparities in utilization of RPN for management of cT1 and cT2 renal masses. METHODS: Patients who underwent RPN and OPN for clinical stage T1 and T2, N0, M0 renal masses from 2010 to 2013 were identified in the National Cancer Data Base (NCDB). Univariate and multivariable logistic regression analyses were performed to evaluate differences in receiving RPN across various patient groups. RESULTS: A total of 23,681 patients fulfilled inclusion criteria. Utilization of RPN for management of cT1/cT2 renal masses significantly increased from 2010 to 2013 compared to OPN (Figure.1). Black (aOR1⁄40.91, 95%CI: 0.84-0.99) and Hispanic (aOR1⁄40.85, 95% CI: 0.76-0.94) patients were less likely to undergo RPN in favor of OPN. RPN was less likely to be performed in rural counties (aOR1⁄4 0.81, 95% CI: 0.66-0.98) and in patients with no insurance (aOR1⁄40.52, 95% CI: 0.45-0.61) or patients covered by Medicaid (aOR1⁄40.81, CI: 0.73-0.89). No significant difference was seen with respect to utilization of RPN between academic and non-academic facilities. Patients with higher clinical stage and co-morbidities were also less likely to undergo RPN (aOR1⁄40.23, 95% CI: 0.150.36 and 0.79, 95% CI: 0.71-0.87 respectively). CONCLUSIONS: Utilization of RPN continues to increase over time; however, there is significant disparity in utilization of RPN based on socio-economic status and race. Black or Hispanic patients and patients in rural communities and with limited insurance were more likely to be treated with OPN instead of RPN.

Complications of Ureteroscopy

Introduction: Complications in ureteroscopy (URS) occur at a low incidence and most are minor but still major complications do happen. It is the responsibility of the surgeon to be able to recognize and manage these complications whether they occur intraoperatively or postoperatively.