Thomas S. Lendvay

Metastatic Adenocarcinoma After Augmentation Gastrocystoplasty

PURPOSE Augmentation gastrocystoplasty has been proposed as an alternative to enterocystoplasty because of potential benefits, including decreased risk of mucus production, stone formation and urinary tract infections. Although cancer has rarely been reported in this patient population, it is a well recognized potential risk of all augmentation cystoplasties. To define better the risk of malignancy associated with gastric augmentation and the appropriate surveillance protocol for these patients, we describe our experience in 2 patients with metastatic adenocarcinoma following gastrocystoplasty. MATERIALS AND METHODS We retrospectively reviewed the charts of all patients who had undergone augmentation gastrocystoplasty between 1990 and 1994. Of the 72 patients identified 2 were diagnosed with a primary malignancy arising from the augmented bladder. Charts were reviewed for medical history, clinical outcomes and pathology. RESULTS Two patients were identified with a primary bladder malignancy after gastrocystoplasty. Both patients had metastatic disease at initial presentation. Neither patient had a history of gross hematuria, recurrent urinary tract infections or pain before initial presentation. Mean patient age at augmentation was 5.5 years. Mean age at diagnosis of malignancy was 19.5 years, with a mean time from augmentation of 14 years. CONCLUSIONS Although the risk of bladder cancer is low after gastric augmentation, the effects may be life threatening. Therefore, we advocate routine annual surveillance with cystoscopy, bladder biopsy and upper tract imaging in all patients who have undergone augmentation gastrocystoplasty.

Comparison of the Learning Curve and Outcomes of Robotic Assisted Pediatric Pyeloplasty

PURPOSE We compared the learning curve and outcomes in children undergoing robotic assisted laparoscopic pyeloplasty during the initiation of a robotic surgery program compared to the benchmark of open pyeloplasty. MATERIALS AND METHODS The records of our first consecutive 33 children undergoing robotic assisted laparoscopic pyeloplasty from 2006 to 2009 were retrospectively reviewed and compared to those of age and gender matched children who underwent open repair done by senior faculty surgeons before the initiation of our robotic surgery program. We compared operative time, complications, postoperative pain, length of stay and surgical success for 2 surgeons who adopted the robotic approach at an academic teaching institution. RESULTS We found no significant differences in length of stay, pain score or surgical success at a median followup of 16 months. The number of complications was similar and they tended to be early and technical in the robotic assisted laparoscopic pyeloplasty group. Overall average operative time was 90 minutes longer (38%) for robotic assisted laparoscopic pyeloplasty (p <0.004). When evaluated chronologically, there was evidence of a learning curve. After 15 to 20 robotic cases overall operative times for robotic assisted laparoscopic cases was consistently within 1 SD of our average open pyeloplasty time with no significant difference in overall operative time (p = 0.23). Of the decrease in overall operative time 70% was due to decreased pyeloplasty time rather than peripheral time. CONCLUSIONS There was similar safety and efficacy with robotic assisted laparoscopic pyeloplasty, although complications tended to be technical and early in our initial experience. Operative time decreased with experience and after 15 to 20 cases it was similar to that of open pyeloplasty with similar outcomes and surgical success.

Augmentation Cystoplasty Rates at Children’s Hospitals in the United States: A Pediatric Health Information System Database Study

PURPOSE We identified augmentation cystoplasty rates in children with spina bifida at childrens hospitals enrolled in the Pediatric Health Information System database. MATERIALS AND METHODS The Pediatric Health Information System database tabulates demographic and diagnostic patient data from 35 childrens hospital centers in the United States. Between October 1999 and September 2004 we extracted data on 0 to 19-year-old patients with International Classification of Diseases-9 diagnosis codes for spina bifida. The International Classification of Diseases-9 procedure code for augmentation cystoplasty was cross-referenced with these patients to determine the total number of patients with augmentation, total population augmentation rates and individual institution rates of bladder augmentation. RESULTS Staff at enrolled pediatric medical centers submitted inpatient data accounting for 9,059 beds servicing an aggregate metropolitan population of 82 million individuals. In the 5-year period 12,925 unique spina bifida patient encounters were identified, including 665 patients who underwent augmentation cystoplasty. The mean 5-year institutional number of augmentations performed in children with spina bifida was 20 (range 1 to 121) and the mean annual number of augmentations performed per institution was 4. The overall augmentation rate at 33 hospitals contributing data for the full years 2000 to 2003 was 5.4% (range 0.5% to 16.3%, p <0.0001). The male-to-female ratio of those who underwent augmentation was 1:1.2. Median length of stay in children with augmentation was 7 days (mean 9). The median age of children with augmentation was 10.4 years, that is 11.3 years in boys and 9.8 years in girls. The difference in mean age was statistically significant (p <0.003). At institutions where 10 or more augmentations were performed in 5 years (mean 27) mean patient age at operation was 10.1 years. This was significantly younger than the mean patient age of 12.3 years at hospitals where fewer than 10 augmentations (mean 5) were done in 5 years (p <0.05). CONCLUSIONS Clinical management for neurogenic bladder conditions has evolved to emphasize nonoperative management. Several studies suggest that aggressive early intervention improves bladder compliance and may protect renal function. However, results from the Pediatric Health Information System database demonstrate no change in augmentation rates during this time and they demonstrate significant interinstitutional variability. To our knowledge this represents the largest series of augmentation cystoplasty in children with spina bifida to date.

Use of 3-Dimensional Printing Technology and Silicone Modeling in Surgical Simulation: Development and Face Validation in Pediatric Laparoscopic Pyeloplasty

OBJECTIVES Pediatric laparoscopy poses unique training challenges owing to smaller workspaces, finer sutures used, and potentially more delicate tissues that require increased surgical dexterity when compared with adult analogs. We describe the development and face validation of a pediatric pyeloplasty simulator using a low-cost laparoscopic dry-laboratory model developed with 3-dimensional (3D) printing and silicone modeling. DESIGN AND SETTING The organs (the kidney, renal pelvis, and ureter) were created in a 3-step process where molds were created with 3D modeling software, printed with a Spectrum Z510 3D printer, and cast with Dragon Skin 30 silicone rubber. The model was secured in a laparoscopy box trainer. A pilot study was conducted at a Canadian Urological Association meeting. A total of 24 pediatric urology fellows and 3 experienced faculty members then assessed our skills module during a minimally invasive surgery training course. Participants had 60 minutes to perform a right-side pyeloplasty using laparoscopic tools and 5-0 VICRYL suture. Face validity was demonstrated on a 5-point Likert scale. PARTICIPANTS AND RESULTS The dry-laboratory model consists of a kidney, a replaceable dilated renal pelvis and ureter with an obstructed ureteropelvic junction, and an overlying peritoneum with an inscribed fundamentals of laparoscopic surgery pattern-cutting exercise. During initial validation at the Canadian Urological Association, participants rated (out of 5) 4.75 ± 0.29 for overall impression, 4.50 ± 0.41 for realism, and 4.38 ± 0.48 for handling. During the minimally invasive surgery course, 22 of 24 fellows and all the faculty members completed the scoring. Usability was rated 4 or 5 by 14 participants (overall, 3.6 ± 1.22 by novices and 3.7 ± 0.58 by experts), indicating that they would use the model in their own training and teaching. Esthetically, the model was rated 3.5 ± 0.74 (novices) and 3.3 ± 0.58 (experts). CONCLUSIONS We developed a pediatric pyeloplasty simulator by applying a low-cost reusable model for laparoscopic training and skills acquisition. The models usability, realism, and feel are good, it can be imaged under common modalities, and it shows promise as an educational tool.

Teleoperation in surgical robotics – network latency effects on surgical performance

A teleoperated surgical robotic system allows surgical procedures to be conducted across long distances while utilizing wired and wireless communication with a wide spectrum of performance that may affect the outcome. An open architecture portable surgical robotic system (Raven) was developed for both open and minimally invasive surgery. The system has been the subject of an intensive telesurgical experimental protocol aimed at exploring the boundaries of the system and surgeon performance during a series of field experiments in extreme environments (desert and underwater) teleportation between US, Europe, and Japan as well as lab experiments under synthetic fixed time delay. One standard task (block transfer emulating tissue manipulation) of the Fundamentals of Laparoscopic Surgery (FLS) training kit was used for the experimental protocol. Network characterization indicated a typical time delay in the range of 16-172 ms in field experiments. The results of the lab experiments showed that the completion time of the task as well as the length of the tool tip trajectory significantly increased (α< 0.02) as time delay increased in the range of 0-0.5 sec increased. For teleoperation with a time delay of 0.25s and 0.5s the task completion time was lengthened by a factor of 1.45 and 2.04 with respect to no time delay, whereas the length of the tools’ trajectory was increased by a factor of 1.28 and 1.53 with respect to no time delay. There were no statistical differences between experienced surgeons and non-surgeons in the number of errors (block drooping) as well as the completion time and the tool tip path length at different time delays.

Future of robotic surgery.

AbstractIn just over a decade, robotic surgery has penetrated almost every surgical subspecialty and has even replaced some of the most commonly performed open oncologic procedures. The initial reports on patient outcomes yielded mixed results, but as more medical centers develop high-volume robotics programs, outcomes appear comparable if not improved for some applications. There are limitations to the current commercially available system, and new robotic platforms, some designed to compete in the current market and some to address niche surgical considerations, are being developed that will change the robotic landscape in the next decade. Adoption of these new systems will be dependent on overcoming barriers to true telesurgery that range from legal to logistical. As additional surgical disciplines embrace robotics and open surgery continues to be replaced by robotic approaches, it will be imperative that adequate education and training keep pace with technology. Methods to enhance surgical performance in robotics through the use of simulation and telementoring promise to accelerate learning curves and perhaps even improve surgical readiness through brief virtual-reality warm-ups and presurgical rehearsal. All these advances will need to be carefully and rigorously validated through not only patient outcomes, but also cost efficiency.

Robot-assisted extravesical ureteral reimplantation: outcomes and conclusions from 78 ureters.

OBJECTIVE Extravesical robot-assisted laparoscopic ureteral reimplantation (RALUR) is a popular alternative to open surgery. We report our experience with RALUR and evaluate clinical variables as predictors for failure. METHODS We retrospectively evaluated the records of patients who underwent RALUR by a single surgeon for treatment of primary vesicoureteral reflux. Clinical and demographic variables were determined. Clinical variables were compared with surgical outcomes using the Student two-tailed type 2 t test. RESULTS Fifty patients underwent a combined 78 extravesical RALURs. Median (range) age was 6.2 (1.9-18.0) years; median (range) preoperative reflux grade was 3 (0-5). Dysfunctional elimination syndrome (DES) was present in 32 (64%). Ten (20%) patients had prior deflux, and two (4%) had prior ureteroneocystostomy on the ipsilateral side. Postoperative cystogram was performed in 100% at a median (range) of 55 (27-133) days. Median (range) follow-up was 286 (27-2238) days. Febrile urinary tract infection occurred in five (10%), none of whom had reflux on initial follow-up postoperative cystogram. All five had a history of DES and were female. Six complications occurred in five (10%) patients, including ileus (2), ureteral obstruction (2), ureteral injury (1), and perinephric fluid collection (1). Transient urinary retention occurred in one. Five of 22 (22.7%) patients undergoing unilateral surgery had contralateral de novo reflux. Six of 78 ureters (7.7%) had persistent reflux postoperatively. Neither persistent nor de novo reflux was associated with any of the clinical variables assessed. CONCLUSIONS RALUR is an effective and safe option for patients with primary vesicoureteral reflux requiring surgery.

Content and Construct Validation of a Robotic Surgery Curriculum Using an Electromagnetic Instrument Tracker

PURPOSE Rapid adoption of robot-assisted surgery has outpaced our ability to train novice roboticists. Objective metrics are required to adequately assess robotic surgical skills and yet surrogates for proficiency, such as economy of motion and tool path metrics, are not readily accessible directly from the da Vinci® robot system. The trakSTAR™ Tool Tip Tracker is a widely available, cost-effective electromagnetic position sensing mechanism by which objective proficiency metrics can be quantified. We validated a robotic surgery curriculum using the trakSTAR device to objectively capture robotic task proficiency metrics. MATERIALS AND METHODS Through an institutional review board approved study 10 subjects were recruited from 2 surgical experience groups (novice and experienced). All subjects completed 3 technical skills modules, including block transfer, intracorporeal suturing/knot tying (fundamentals of laparoscopic surgery) and ring tower transfer, using the da Vinci robot with the trakSTAR device affixed to the robotic instruments. Recorded objective metrics included task time and path length, which were used to calculate economy of motion. Student t test statistics were performed using STATA®. RESULTS The novice and experienced groups consisted of 5 subjects each. The experienced group outperformed the novice group in all 3 tasks. Experienced surgeons described the simulator platform as useful for training and agreed with incorporating it into a residency curriculum. CONCLUSIONS Robotic surgery curricula can be validated by an off-the-shelf instrument tracking system. This platform allows surgical educators to objectively assess trainees and may provide credentialing offices with a means of objectively assessing any surgical staff member seeking robotic surgery privileges at an institution.

Measuring to Improve: Peer and Crowd-sourced Assessments of Technical Skill with Robot-assisted Radical Prostatectomy

UNLABELLED Because surgical skill may be a key determinant of patient outcomes, there is growing interest in skill assessment. In the Michigan Urological Surgery Improvement Collaborative (MUSIC), we assessed whether peer and crowd-sourced (ie, layperson) video review of robot-assisted radical prostatectomy (RARP) could distinguish technical skill among practicing surgeons. A total of 76 video clips from 12 MUSIC surgeons consisted of one of four parts of RARP and underwent blinded review by MUSIC peer surgeons and prequalified crowd-sourced reviewers. Videos were rated for global skill (Global Evaluation Assessment of Robotic Skills) and procedure-specific skill (Robotic Anastomosis and Competency Evaluation). We fit linear mixed-effects models to estimate mean peer and crowd ratings for each video. Individual video ratings were aggregated to calculate surgeon skill scores. Peers (n=25) completed 351 video ratings over 15 d, whereas crowd-sourced reviewers (n=680) completed 2990 video ratings in 38 h. Surgeon global skill scores ranged from 15.8 to 21.7 (peer) and from 19.2 to 20.9 (crowd). Peer and crowd ratings demonstrated strong correlation for both global (r=0.78) and anastomosis (r=0.74) skills. The two groups consistently agreed on the rank order of lower scoring surgeons, suggesting a potential role for crowd-sourced methodology in the assessment of surgical performance. Lack of patient outcomes is a limitation and forms the basis of future study. PATIENT SUMMARY We demonstrated the large-scale feasibility of assessing the technical skill of robotic surgeons and found that online crowd-sourced reviewers agreed with experts on the rank order of surgeons with the lowest technical skill scores.

Surgical Management of Congenital Ureteropelvic Junction Obstruction: A Pediatric Health Information System Database Study

PURPOSE Although laparoscopic pyeloplasty has gained popularity, to our knowledge no multi-institutional study has evaluated the prevalence of this approach in children. We used a multicenter database to determine trends in the treatment of congenital ureteropelvic junction obstruction. MATERIALS AND METHODS The Pediatric Health Information System database contains data on 37 freestanding hospitals for children across the United States. We extracted data on 0 to 19-year-old patients from 2001 to 2006 with the ICD-9 diagnosis code for congenital ureteropelvic junction obstruction and the procedure code for the correction of ureteropelvic junction obstruction. We identified laparoscopic cases based on hospital charges for 1) laparoscope, 2) trocar, 3) insufflating needle or 4) insufflator and tubing. Data were then analyzed using the chi-square and Student t tests to determine management trends. RESULTS We identified 2,353 patients, of whom 2,177 (92.5%) underwent open pyeloplasty and 176 (7.5%) underwent laparoscopic pyeloplasty. The percent of pediatric pyeloplasties performed laparoscopically increased from 2001 to 2003 (2.53% to 9.73%) and has since remained stable. Patients undergoing laparoscopic pyeloplasty were significantly older than those in the open group (age 8.2 vs 3.3 years, p <0.0001). Average hospital charges were significantly higher in the laparoscopic group than in the open group (