Pierre J. Mendoza

VerroTouch: High-Frequency Acceleration Feedback for Telerobotic Surgery

The Intuitive da Vinci system enables surgeons to see and manipulate structures deep within the body via tiny incisions. Though the robotic tools mimic ones hand motions, surgeons cannot feel what the tools are touching, a striking contrast to non-robotic techniques. We have developed a new method for partially restoring this lost sense of touch. Our VerroTouch system measures the vibrations caused by tool contact and immediately recreates them on the master handles for the surgeon to feel. This augmentation enables the surgeon to feel the texture of rough surfaces, the start and end of contact with manipulated objects, and other important tactile events. While it does not provide low frequency forces, we believe vibrotactile feedback will be highly useful for surgical task execution, a hypothesis we we will test in future work.

Rectal Injury During Robot-Assisted Radical Prostatectomy: Incidence and Management

PURPOSE Rectal injury during robot-assisted radical prostatectomy is a rare but significant complication. Since the Clavien grading classification of complications does not include intraoperative injury without further sequelae, rectal injury may be underreported in the literature. We present what is to our knowledge the largest retrospective review to date of rectal injury and subsequent management. MATERIALS AND METHODS We reviewed the records of 6,650 patients who underwent robot-assisted radical prostatectomy at a total of 6 institutions. Patient characteristics, perioperative parameters, pathological findings and rectal injury management were tabulated and analyzed for intraoperative predictors of outcome and subsequent management. RESULTS A total of 11 rectal injury cases were identified of the 6,650 robot-assisted radical prostatectomies for a combined 0.17% incidence of rectal injury. Of rectal injuries 72.7% were identified intraoperatively and most did well with primary closure. Delayed recognition injury presented as rectourethral fistula without septic complications and required delayed fistula repair after primary diversion. We found no conclusive association of rectal injury with any patient parameter, intraoperative differences, pathological finding or surgeon experience. Posterior prostate plane dissection, including seminal vesicle dissection, is the crucial stage when rectal injury can occur and be identified. CONCLUSIONS Our review of the records at 6 centers revealed a combined 0.17% incidence of rectal injury. This compares favorably to the incidence in modern open and laparoscopic radical prostatectomy series. No preoperative, intraoperative or pathological differences correlated with injury. Cases in which rectal injury was identified intraoperatively required fewer surgical repeat interventions but ultimately each group had acceptable long-term urinary and bowel function results.

Stress incontinence during the learning curve of holmium laser enucleation of the prostate.

BACKGROUND AND PURPOSE Holmium laser enucleation of the prostate (HoLEP) is an excellent surgical treatment for patients with benign prostatic hyperplasia, but surgical complications are not well described. We set out to determine the predictors of stress incontinence (SUI) after HoLEP during the learning curve. PATIENTS AND METHODS A retrospective review of our institutions HoLEP database was performed. Patients were divided into two groups: No pads at 3 months (group 1); SUI and/or mixed incontinence necessitating ≥ one pad at 3 months (group 2). RESULTS Seventy-seven patients underwent HoLEP at our institution. Nine (12%) were excluded for pure urge symptoms and two (3%) were lost to follow-up, leaving 66 total patients. No differences were noted as regards age (P = 0.54), operating room time (P = 0.18), prostate size (P = 0.85), prostate-specific antigen level (P = 0.96), or International Prostate Symptom Score (P = 0.11). The number of days between cases, however, was higher in group 2 (44.5 vs 18.1, P = 0.02) and was associated with SUI in simple logistic regression models (odds ratio [OR] 1.25; 95% confidence interval [CI]: 1.04-1.51; P = 0.019). As the interval time between cases increased from 1, 3, and 5 weeks, the strength of the association increased (1 week: OR 2.75; 95% CI: 0.78-9.66; P = 0.12; 3 weeks: OR 2.86; 95% CI: 0.92-8.91; P = 0.07; 5 weeks: OR 4.69; 95% CI: 1.21-18.26; P = 0.026). SUI resolved in all but two patients by 1 year. CONCLUSIONS The major associated risk for SUI, a complication presumably related to surgical technique, was prolonged duration between cases. During the learning curve, surgeons should schedule patients frequently to enhance learning and decrease time to mastery of the technique, thereby reducing SUI.

Bladder neck plication stitch: a novel technique during robot-assisted radical prostatectomy to improve recovery of urinary continence.

BACKGROUND AND PURPOSE Efforts to improve postprostatectomy incontinence have led to many modifications in surgical technique. We present our experience with a novel technique to improve continence outcomes in patients who are undergoing robot-assisted radical prostatectomy (RARP). PATIENTS AND METHODS A consecutive series of 159 patients after initiation of a bladder neck plication stitch was compared with the most recent group before the change. After completion of the vesicourethral anastomosis, a single suture was used to plicate the distal bladder neck. A structured questionnaire was used for follow-up. Continence criteria used were 1 pad per day for social continence and 0 pad per day for total continence. RESULTS A total of 334 patients were included in the study: 159 in the plication stitch group vs 175 in the control group. Average age was 59.1 vs 59.6 years, average body mass index was 27.9 vs 28.3 kg/m(2), and average prostate volume was 58.1 vs 60.9 cc, respectively. The mean time to reach social continence was 3.63±3.01 vs 5.33±4.89 weeks (P=0.004), and total continence was 5.10±3.80 vs 8.49±6.32 weeks (P=0.002), respectively. Chance of total continence improved with the bladder plication stitch: Odds ratio of 1.95±0.72 (P<0.001) at 1 month, 1.25±0.56 (P=0.113) at 3 months, and 2.07±0.66 (P=0.005) at 12 months. There were no bladder neck contractures or other urinary complications noted in either group. CONCLUSIONS The bladder plication stitch is a simple and effective technical modification for shortening the period of recovery of urinary continence in RARP patients. Randomized controlled trials are under way to further evaluate this technique.

Pelvic Anatomy on Preoperative Magnetic Resonance Imaging Can Predict Early Continence After Robot-Assisted Radical Prostatectomy

BACKGROUND AND PURPOSE Postoperative incontinence is multifactorial after radical prostatectomy. Using endorectal coil MRI, we examined features of the male urethra and accompanying muscular sphincter to predict continence after robot-assisted radical prostatectomy (RARP). PATIENTS AND METHODS 80 patients underwent preoperative 1.5 Tesla endorectal coil MRI. Urethral length was measured in the coronal plane. All patients underwent RARP. Questionnaires were completed by patients at monthly intervals. The primary end point was time to continence defined as necessitating 0 to 1 pad per day (PPD). Statistical analysis was performed using Cox regression models to create both univariate and multivariate survival models. RESULTS Mean age was 59.7 (standard deviation [SD] 7.1); 98% had bilateral nerve sparing. Mean urethral length was 17.1 mm (SD 4.5 mm). Mean prostate size was 34.7 g (SD 17.8). By 3 months, 60 patients achieved 1 PPD (mean 8.1 weeks, SD 9.4) and 34 patients achieved 0 PPD (mean 10.5 weeks, SD 8.0). Time to social continence was significantly related to prostate size both as a continuous variable (P=0.01), and as a dichotomized variable of ≥ 50 vs<50 g (P=0.02). Increased urethral length was related to decreased time to continence both as a continuous variable (P=0.06), and when dichotomized to ≥ 20 vs<20 mm (P=0.08). In addition to larger prostate size (hazard ratio [HR] 0.97, P<0.04), older age (0.95 P<0.025) was also associated with a longer time to achieve 0 PPD. Multivariate analysis revealed that longer urethral length was associated with a faster recovery of continence (HR 1.11, P<0.01). After controlling for age and urethral length, patients with a prostate size ≥ 50 g had 75% lower likelihood of achieving continence at all time points when compared with patients with prostate size <50 g (HR 0.25; 95% confidence interval: 0.06, 1.06; P=0.06). CONCLUSIONS Longer urethral length increased the likelihood of achieving continence at all time points postoperatively. Advanced age and larger prostate size were negatively associated with continence outcomes.

Robot-Assisted Excision of a Retroperitoneal Mass Between the Left Renal Artery and Vein

Extraadrenal pheochromocytomas are rare and can present in difficult locations. In this case, the da Vinci robot was used for the safe management of this perihilar mass.

Techniques to Improve Urinary Continence Following Robot-Assisted Radical Prostatectomy

Robot-assisted radical prostatectomy (RARP) is rapidly gaining popularity in the urologic community. Since its advent, this technique has benefited patients by achieving quicker convalescence. However, this improvement has also driven efforts to improve the functional outcomes after RARP with promising early results. This cutting edge approach provides advantages including enhanced visualization, dexterity, and instrumentation. However, specific techniques to minimize the anatomic and neuro-physiologic risks need to be further elucidated.

Erratum to: Surgeon perception is not a good predictor of peri-operative outcomes in robot-assisted radical prostatectomy (J Robotic Surg, 10.1007/s11701-011-0293-4)

Surgeons have always used their cognitive intuition for the execution of skilled tasks and real-time perception of intra-operative outcomes. We attempted to measure the overall accuracy of intra-operative surgeon perception on the functional outcome of early continence after robot-assisted radical prostatectomy (RARP). A single experienced surgeon (D.I.L.) used a scoring sheet to prospectively capture his subjective opinion of how well a particular portion of the RARP procedure was completed. Surgeon perception of factors affecting post-operative continence such as quality of bladder neck preservation, nerve sparing, urethral length, anastomosis, striated sphincter thickness, quality of Rocco repair and bladder neck plication suture (total 7 variables) were graded as ‘‘poor’’, ‘‘average’’ or ‘‘good’’. Urinary continence was graded as either total continence [0 pads per day (PPD) or social continence (security pad or one PPD)]. A total of 273 (39 patients 9 7 variables) responses were recorded: 58.6% were rated as ‘‘good’’, 32.2% as ‘‘average’’ and 8.4% as ‘‘poor’’. A log-rank test for all perception variables showed no significant differences in subsequent achievement of continence (either 0 or 1 PPD) (P [ 0.05) at both the 1and 3-month time points. In the case of some perception variables, patients with ‘‘bad’’ scores gained continence a median of 3 weeks sooner than patients with ‘‘good’’ scores. Surgeon perception of intra-operative performance during RARP is a poor predictive indicator of subsequent functional outcome in terms of urinary continence. Intersurgeon variability of perception may vary and needs further investigation.