Iryna Makovey

Congenital Penile Curvature: Update and Management

Congenital penile curvature results from disproportionate development of the tunica albuginea of the corporal bodies and is not associated with urethral malformation. Patients usually present after reaching puberty as the curvature becomes more apparent with erections, and severe curvature can make intercourse difficult or impossible, at which point surgical repair is recommended. Excellent outcomes can be expected with surgical intervention. The three most commonly used repair techniques are the original Nesbit procedure, modified Nesbit procedure, and plication. Nesbit and modified Nesbit techniques require that an incision is made in the tunica albuginea while plication techniques utilize plicating sutures without an incision. While Nesbit and modified Nesbit techniques are more complex operations, these generally result in less recurrences and more satisfactory outcomes as opposed to the quicker and simpler plication technique.

Real-Time Classification of Bladder Events for Effective Diagnosis and Treatment of Urinary Incontinence

Diagnosis of lower urinary tract dysfunction with urodynamics has historically relied on data acquired from multiple sensors using nonphysiologically fast cystometric filling. In addition, state-of-the-art neuromodulation approaches to restore bladder function could benefit from a bladder sensor for closed-loop control, but a practical sensor and automated data analysis are not available. We have developed an algorithm for real-time bladder event detection based on a single in situ sensor, making it attractive for both extended ambulatory bladder monitoring and closed-loop control of stimulation systems for diagnosis and treatment of bladder overactivity. Using bladder pressure data acquired from 14 human subjects with neurogenic bladder, we developed context-aware thresholding, a novel, parameterized, user-tunable algorithmic framework capable of real-time classification of bladder events, such as detrusor contractions, from single-sensor bladder pressure data. We compare six event detection algorithms with both single-sensor and two-sensor systems using a metric termed Conditional Stimulation Score, which ranks algorithms based on projected stimulation efficacy and efficiency. We demonstrate that adaptive methods are more robust against day-to-day variations than static thresholding, improving sensitivity and specificity without parameter modifications. Relative to other methods, context-aware thresholding is fast, robust, highly accurate, noise-tolerant, and amenable to energy-efficient hardware implementation, which is important for mapping to an implant device.

The effect of time to release of an obstructing synthetic mid-urethral sling on repeat surgery for stress urinary incontinence.

The primary objectives were to describe the rate of repeat surgery for stress urinary incontinence (SUI) after release of an obstructing synthetic mid‐urethral sling (MUS) and to evaluate the effect of time from sling placement to sling release on repeat surgery rates. The secondary objective was to assess rates of recurrent and persistent SUI.

Wireless implantable pressure monitor for conditional bladder neuromodulation

Conditional neuromodulation in which neurostimulation is applied or modified based on feedback is a viable approach for enhanced bladder functional stimulation. Current methods for measuring bladder pressure rely exclusively on external catheters placed in the bladder lumen. This approach has limited utility in ambulatory use as required for chronic neuromodulation therapy. We have developed a wireless bladder pressure monitor to provide real-time, catheter-free measurements of bladder pressure to support conditional neuromodulation. The device is sized for submucosal cystoscopic implantation into the bladder. The implantable microsystem consists of an ultra-low-power application specific integrated circuit (ASIC), micro-electro-mechanical (MEMS) pressure sensor, RF antennas, and a miniature rechargeable battery. A strategic approach to power management miniaturizes the implant by reducing the battery capacity requirement. Here we describe two approaches to reduce the average microsystem current draw: switched-bias power control and adaptive rate transmission. Measurements on human cystometric tracings show that adaptive transmission rate can save an average of 96% power compared to full-rate transmission, while adding 1.6% RMS error. We have chronically implanted the wireless pressure monitor for up to 4 weeks in large animals. To the best of our knowledge these findings represent the first examples of catheter-free, realtime bladder pressure sensing from a pressure monitor chronically implanted within the bladder detrusor.

Response to the U.S. Preventative Services Task Force decision on prostate cancer screening

The population-level data demonstrate that the inception of prostate-specific antigen (PSA) screening has lowered mortality for prostate cancer over the past 2 decades. However, more recent evidence from randomized trials has presented conflicting results regarding the benefit of PSA screening for prostate cancer mortality. Using available data, the U.S. Preventative Services Task Force recently recommended against PSA screening for prostate cancer. However, prostate cancer continues to kill over 30,000 men annually, and as such, completely abandoning screening for this disease is a disservice to many patients. Rather, the emphasis should be on utilizing evidence-based medicine to reduce overdiagnosis and overtreatment through less frequent screening for low-risk individuals or those unlikely to benefit from screening, halting further screening when appropriate, and utilizing observational strategies in patients unlikely to suffer clinically significant effects of prostate cancer over their anticipated life expectancy.

Wireless bladder pressure monitor for closed-loop bladder neuromodulation

Conditional neuromodulation is a form of closed-loop bladder control where neurostimulation is applied in reaction to bladder pressure changes. Current methods based on external catheters have limited utility for chronic ambulatory therapy. We have developed a wireless pressure monitor to provide real-time, catheter-free detection of bladder contractions. The device is sized for chronic implantation in the bladder muscle. The pressure monitor consists of an ultra-low-power application specific integrated circuit (ASIC), micro-electro-mechanical (MEMS) pressure sensor, RF antennas, and rechargeable battery. Here we describe an overview of the system, including chronic in vivo test data of a non-hermetic polymer sensor package and chronic testing of the wireless sensor in large animal models. Test results show that the packaging method is viable for chronic encapsulation of implanted pressure sensors. Chronic testing of the pressure monitor revealed some obstacles relating to the chosen implant site within the bladder wall. However, chronic wireless device function was confirmed and data quality was sufficient to detect bladder compressions in large animals, with average correlation coefficient of 0.90.

Clinical and regulatory considerations of implantable medical devices

Abstract Development of an implantable medical device starts with an aim of addressing a clinical need and improving patient outcomes while minimizing risks. Clinical considerations for device development focus on the unique patient population needs and limitations, the implant environment and local tissue response to the device, and the need for durability or biodegradability. Additionally, the design must account for the techniques of implantation or explantation while minimizing risk of infections and addressing the management plan for possible complications. Finally, each device is subject to rigorous review by the Food and Drug Administration. This chapter will review basic clinical considerations of an implantable medical system and will discuss regulatory principles and steps of the device approval process.

Is submucosal bladder pressure monitoring feasible

There has been recent interest in placing pressure-sensing elements beneath the bladder mucosa to facilitate chronic bladder pressure monitoring. Wired submucosal sensors with the wires passed through detrusor have been demonstrated in vivo, with limited chronic retention, potentially due to the cable tethering the detrusor. Published studies of submucosal implants have shown that high correlation coefficients between submucosal and lumen pressures can be obtained in caprine, feline, and canine models. We have developed a wireless pressure monitor and surgical technique for wireless submucosal implantation and present our initial chronic implantation study here. Pressure monitors were implanted (n = 6) in female calf models (n = 5). Five devices were implanted cystoscopically with a 25-French rigid cystoscope. One device was implanted suprapubically to test device retention with an intact mucosa. Wireless recordings during anesthetized cystometry simultaneous with catheter-based reference vesical pressure measurements during filling and manual bladder compressions were recorded. Individual analysis of normalised data during bladder compressions (n = 12) indicated high correlation (r = 0.85–0.94) between submucosal and reference vesical pressure. The healing response was robust over 4 weeks; however, mucosal erosion occurred 2–4 weeks after implantation, leading to device migration into the bladder lumen and expulsion during urination. Wireless pressure monitors may be successfully placed in a suburothelial position. Submucosal pressures are correlated with vesical pressure, but may differ due to biomechanical forces pressing on an implanted sensor. Fully wireless devices implanted beneath the mucosa have risk of erosion through the mucosa, potentially caused by disruption of blood flow to the urothelium, or an as-yet unstudied mechanism of submucosal regrowth. Further investigation into device miniaturisation, anchoring methods, and understanding of submucosal pressure biomechanics may enable chronic submucosal pressure monitoring. However, the risk of erosion with submucosal implantation highlights the need for investigation of devices designed for chronic intravesical pressure monitoring.

MP33-08 RESOLUTION OF URGENCY URINARY INCONTINENCE AFTER INCISION OF AN OBSTRUCTING SYNTHETIC SLING

INTRODUCTION AND OBJECTIVES: Women with iatrogenic obstruction after synthetic sling placement often present with de novo or worsening urgency, frequency, and urgency urinary incontinence (UUI). The objective of this study was to determine the optimal time for sling incision to achieve resolution of urgency urinary incontinence. METHODS: 72 women who had a synthetic mid-urethral sling placed, developed de-novo or worsening urgency urinary incontinence, and then underwent sling incision for obstruction, were included in the study. On follow-up, women were administered UDI-6 and satisfaction questionnaires. ROC analysis was utilized to determine a statistically significant time point for sling incision with regard to resolution of urgency urinary incontinence. This cut-off was used to create early and delayed incision groups, which were compared using Wilcoxon rank-sum test for continuous variables and chi-square test for categorical variables. Multivariable logistic regression analysis was used to evaluate the association between early vs. delayed sling incision surgery and resolution of UUI and persistence of UUI while adjusting for age, BMI, diabetes, smoking status, vaginal parity, and sling approach. RESULTS: Median age was 55 (95%CI 51-59). Median number of months of follow-up after sling incision was 22 (95%CI 15-31). Median number of months from sling placement to sling incision was 25 (95%CI 16-32). ROC analysis revealed statistical significance using a cutpoint for resolution of UUI at 24 months. Rate of resolution of UUI was lower in the delayed incision group. UUI was more severe in the delayed incision group. See Table. Multivariable regression analysis revealed that women who underwent delayed incision were more likely to have persistent urgency urinary incontinence compared to women who underwent early incision (OR 2.13, 95% CI 0.42-10.8), though this was not statistically significant. CONCLUSIONS: Delayed sling incision results in lower rates of resolution of UUI. Women with de-novo or worsening UUI, presumably related to iatrogenic obstruction, should undergo sling incision sooner, rather than later. Women considering sling incision beyond 24 months should be counseled regarding lower rates of UUI resolution.