Köhler, Tobias

Abstract Objective . Penile vibro-elastography (PVE) is complicated by reverberant shear wavefields from the cylindrical geometry of the corpus cavernosum (CC), which bias shear wave speed (SWS) estimates. This study evaluated local phase velocity imaging with wavefield-based filtering (LPVI-WBF) for CC stiffness assessment in post-prostatectomy erectile dysfunction (ED), compared against phase gradient (PG) and time-of-flight (TOF) methods. Approach . Six patients with post-prostatectomy ED underwent PVE at four longitudinal visits (902 acquisitions). SWS was estimated in flaccid and erect states at 100, 150, and 200 Hz using LPVI-WBF, PG, and TOF. Wavefield composition was quantified via the standing wave index. Simulations evaluated accuracy and frequency stability under clean and reverberant conditions. Main results . Reverberant components dominated penile acquisitions, with traveling wave energy absent in 59% of acquisitions and mean standing wave fraction of 57 ± 17%. LPVI-WBF was the only method producing physiologically consistent estimates, with erect SWS exceeding flaccid (3.59 ± 0.48 vs 3.25 ± 0.58 m s −1 , p < 0.0001). PG and TOF yielded reversed results ( E < F, p < 0.0001). The dispersion exponent was near-zero for LPVI-WBF ( α = 0.048, p = 0.21), consistent with weakly viscoelastic tissue, while PG ( α = 0.184) and TOF ( α = 0.321) showed significant frequency dependence from reverberant contamination. Simulations confirm PG accuracy in clean wavefields but collapse under reverberant ones. Significance . LPVI-WBF produced SWS estimates consistent with expected CC biomechanics across all patients and frequencies, a criterion PG and TOF failed to satisfy. Phantom validation and multi-directional wavefield simulation are needed to establish accuracy.

Abstract Introduction The EROS (Erectile Restoration Outcomes and Satisfaction) registry provides prospective, questionnaire-based follow-up after IPP, established in 2020. Objective We sought to assess general trends in the open-ended responses portion of the questionnaire. Methods Data were collected from 2020 to 2025, with a total of 568 responses. The survey included six open-ended questions pertaining to lifestyle change since IPP, reasons not to repeat the procedure, impediments to use, dissatisfaction, what patients wish they had known more about the procedure, and other recommendations. Evaluable data included 6-month responses from Rochester, Jacksonville, and Phoenix. Results Open-ended feedback was given by 66% of patients on what they wished they had known, 54% gave other recommendations, 38% gave lifestyle feedback, 7% elaborated upon reasons not to use, 3% on reasons for dissatisfaction, and 2% on reasons they would not repeat IPP. There was an overall very positive response (“Significant Improvement”, n=74.3%) from those who underwent the IPP placement, with some patients reporting that it was far more convenient than other forms of treatment, and even increased spontaneity in their sexual lives, leading to improved relationships. Among the reported responses are increased confidence (n=39.4%), increased sexual activity (n=13.3%), and improved health and exercise levels (n=6.6%). When questioning patients about why they would not repeat the procedure and what their sources of dissatisfaction were, among those who responded to each question (n=12, n=16), the most frequently reported complaint was the exaggeration of pre-existing curves (n=41.7%, n=25.0%), particularly due to Peyronie’s disease. When questioned about what prevents use, the main responses were partner-related or due to personal problems (n=45.2%). The patients did not have many recommendations, but hoped for a better way to deflate and inflate the device (n=20.4%) and reported adequate pre-operative education and use of the pump. The table below outlines the categories of responses and the percentage of each keyword reported per question type. Conclusions In addition to standard pre-operative IPP counseling, providers should also focus on potential difficulties with device inflation/deflation, length loss (IPP not in the glans), pain/ recovery expectations, the potential for new or worsened curve (erect or flaccid), and potential changes in sensation. IPP satisfaction is high, as only 2% of patients gave responses on why they would not repeat the IPP, with many men expressing an increased level of overall confidence. Disclosure No

Abstract Introduction 0.05% Chlorhexidine Gluconate (CHG) has gained popularity as an irrigant and dip for inflatable penile prosthesis (IPP) surgery. Prior in vitro data is conflicting on the impact of CHG use with hydrophilic coated devices. Objective We sought to identify possible associations between CHG use and hydrophilic IPP infection rate. Methods We conducted a retrospective cohort study of 2,933 patients undergoing IPP implantation across 14 referral centers. Data collection spanned from January 1, 2017 to March 1, 2024. Each surgeon contributed patients who underwent IPP implantation with CHG used as an irrigant and/or dip as well as an equal number of consecutive control patients without CHG use. The primary outcome was IPP explant for postoperative infection. Univariable analysis was used to compare patient demographics, and logistic regression analysis was performed to assess factors associated with infection. Results Hydrophilic devices were implanted in 2,150 patients. Median follow-up for non-CHG patients was 13 months (IQR 18) and four months (IQR 9) for CHG patients. The incidence of infection with intraoperative CHG use was significantly higher compared to those without CHG use (4.6%, 46/1,001 vs. 2.1%, 24/1,148, p&lt;0.001). On multivariable logistic regression analysis, intraoperative CHG use was associated with infection (OR 2.07, 95% CI 1.24-3.47, p=0.01). Additional variables associated with infection included immunosuppression, prior IPP infection, prior priapism, and revision surgery (p&lt;0.01, Table). On subgroup analyses, the increased infection risk of CHG was most clear when CHG was used as both irrigation and dip (OR 2.03, 95% CI 1.19-3.46, p=0.01) and when CHG was used during revision surgery (OR 3.36, 95% CI 1.15-9.82, p=0.03). Conclusions In a large multi-institutional cohort, intraoperative CHG use was associated with an elevated incidence of hydrophilic IPP infection. Providers may take these findings into consideration when performing IPP surgery with hydrophilic devices, especially during revision surgery. Disclosure Any of the authors act as a consultant, employee or shareholder of an industry for: Intuitive Surgical, Fidelis, Urofill, Boston Scientific, Coloplast, Cynosure, Antares Pharma, Clarus Pharmaceuticals, Acerus Pharma; Endo Pharma

Abstract Introduction The optimal antimicrobial prophylaxis strategy for inflatable penile prosthesis (IPP) surgery remains a subject of ongoing investigation. Our institution recently discontinued the use of chlorhexidine gluconate (CHG) and returned to traditional antibiotic-based prophylaxis protocols. Objective To evaluate infection rates following the reinstitution of antibiotic-based prophylaxis after discontinuing CHG in IPP surgery. Methods We conducted a retrospective, consecutive cohort study of patients who underwent Coloplast Titan IPP insertion between May 2024 and May 2025. The antibiotic prophylaxis protocol consisted of rifampin/gentamicin device dipping and vancomycin/gentamicin irrigation. Primary and revision cases were analyzed separately. Results A total of 188 patients underwent IPP insertion during the study period, including 119 primary implantations and 69 revision procedures. Mean patient age was 69.6 ± 11.5 years, BMI was 27.6 ± 4.2 kg/m2, and operative time was 67.1 ± 24.1 minutes. No infections occurred in the primary implantation cohort. One infection (1.4%) occurred in the revision group in a diabetic patient with prolonged operative time (176 minutes). Compared to our previously published data using CHG, infection rates decreased significantly in the revision group (1.4% vs. 9.67%, p &lt; 0.001), while the primary group showed a numerical reduction from 2.22% to 0%. Conclusions The reinstitution of antibiotic following discontinuation of CHG resulted in significantly lower infection rates, particularly in revision cases. These findings support the continued use of antibiotic dipping and irrigation protocols for IPP surgery as a safe and effective strategy for infection prevention. Disclosure No

Abstract Introduction Device malfunction remains a serious concern for patients with inflatable penile prosthesis (IPP), with pump failure being one of leading causes of revision surgery. Complete device replacement has been the traditional approach, but partial device replacement for the pump may offer a less invasive and cost-effective alternative, with potentially lower complication risk. Objective To evaluate the safety, efficacy, and clinical outcomes of pump replacement (with or without obvious tubing leak/fracture), manipulation or fluid addition in patients undergoing IPP revision surgery. Methods A retrospective review was conducted on patients who underwent IPP pump replacement with or without additional component exchange by a single surgeon, between January 2018 and April 2025. Thirty patients met the inclusion criteria. Clinical, intraoperative and postoperative data were collected and descriptively analyzed. Outcomes included postoperative infectious and non-infectious complication rates. Results The median age at revision was 77 years, with a median time to revision of 76 months post-implantation. Most common indications were frozen or pump difficulties (67%), pump + tubing damage (30%) and fluid addition requirement (10%). No intraoperative complications occurred. Postoperative complications were reported in 3 patients (10.0%), all due to mechanical malfunction, with no infections observed. Median time to complication was 24 months (IQR 7–72). One patient progressed to IPP explanation after successive revisions for impending erosion not thought related to pump manipulation. Another underwent complete replacement at 7 months for fluid leak from reservoir. A third required non-exchange revision at 24 months. The majority (91%) received Coloplast pumps. The median operative time was 53 minutes (IQR 43–70). Conclusions Pump replacement appears to be a safe and effective option for select patients, potentially reducing surgical morbidity and preserving viable components. The absence of infection in this series is reassuring, particularly in a revision setting where infection risk is amplified. Consideration of device age and patient specific factors is important in guiding the choice between partial and complete component exchange. Disclosure No

Abstract Introduction Infection following inflatable penile prosthesis (IPP) placement is an uncommon yet serious complication, and its management poses significant clinical challenges. IPP infection management strategies continue to evolve, however, multicenter and robust studies evaluating and describing current practice patterns are lacking. Objective Using a large cohort from tertiary IPP referral centers in the United States to evaluate current infection management practice patterns and to identify factors that could predict the approach to managing IPP infections. Methods We queried a retrospective 14-center multi-institutional database for patients with IPP infections between April 2017 and January 1/2025. Patients were categorized by infection management strategy, which included device explant, malleable salvage, and 3-piece IPP salvage. Patient characteristics were compared using chi-square and independent t-tests. Multinomial analysis was performed to investigate patient and perioperative factors associated with management strategy at the time of infection. Results Among 2,934 cases, 85 (2.9%) patients developed IPP infection at a median of 40 (22-78) days after IPP implantation. Infections occurred after primary IPP surgery in 59 (69%), revision in 25 (29%), and after infection salvaged with IPP in 1 (1%). Infections were managed with device explant in 32 (38%), malleable salvage in 43 (51%), and IPP salvage in 10 (12%). A significantly higher proportion of non-White patients underwent salvage (either with malleable or IPP) compared to White patients (p=0.01). Multinomial regression showed no association between patient and perioperative characteristics and infection management (p&gt;0.05). Conclusions In this multi-institutional cohort of experienced implanters, infections were most commonly managed with malleable salvage. Patient and perioperative factors did not predict management approach, suggesting that the decision between explanation and salvage is primarily driven by individual surgeon preference. Disclosure Any of the authors act as a consultant, employee or shareholder of an industry for: Boston scientific

Abstract Introduction Glans ischemia and subsequent necrosis is a rare but devastating complication of inflatable penile prosthesis (IPP) placement. Differentiating true glans ischemia from severe ecchymosis can be difficult but is critical, particularly in light of the adage, “when in doubt, take it out.” However, post-operative glans discoloration can be misleading and result in premature device explantation. Objective To present clinical cases and identify distinguishing features between true glans ischemia and pronounced post-operative ecchymosis, with emphasis on risk factors and evaluation techniques. Methods A retrospective case series was conducted on four IPP patients in 2025 who presented with significant glans discoloration concerning for ischemia. Key operative variables, physical exam findings, and postoperative images were reviewed. Additionally, a prospective database of 298 implants placed under local anesthesia since 2024 was analyzed for glans bruising severity on postoperative day (POD) 3, using a 0–4 scale. Results Common ischemia risk factors included tight circumferential wrap (e.g., Coban), vasculopathy (e.g., prior arterial bypass), prolonged catheterization, and concomitant procedures. Case 1: History of pelvic radiation with ecchymotic meatus and glans. Improved after wrap removal and better lighting. Case 2: Extensive ecchymosis and discoloration of glans and scrotum noted on POD1 after uneventful IPP under local. Case 3: Patchy glans discoloration after multiple Keith needle passes. Skin tone complicated assessment. Case 4: Severe glans bruising immediately post-op following multiple needle passes due to suture breakage. In all cases, the glans was warm, well-perfused, and not painful out of proportion to appearance. No patients required explantation. Glans bruising rates in 298 implants under local anesthesia were: 0 (3.7%), 1 (48.7%), 2 (25.5%), 3 (21.1%), 4 (0.3%), notably higher than with general anesthesia. Key Clinical Indicators: Favors Hematoma: • Vascular corpora • Small/no catheter • Bruising elsewhere • Wrap excluded glans • No blistering • No paresthesias • Glans warm to touch Favors Ischemia: • Avascular corpora • Large indwelling catheter • Minimal bruising elsewhere • Coban wrap on shaft • Blistering present • Pain or paresthesias • Glans cold to touch Conclusions Significant glans bruising can mimic ischemia, particularly in IPPs placed under local anesthesia. Factors such as multiple Keith needle passes, tight wrapping, and poor photographic lighting may contribute to this diagnostic confusion. Warm, non-painful glans with widespread ecchymosis are reassuring. Avoiding premature explantation requires thorough clinical assessment, device unwrapping, and close patient monitoring. Disclosure Any of the authors act as a consultant, employee or shareholder of an industry for: UroFill, Coloplast, Boston Scientific, Rigicon

Abstract Introduction While Rezum therapy has demonstrated efficacy in treating lower urinary tract symptoms associated with benign prostatic hyperplasia (BPH), its outcomes in catheter-dependent patients remain poorly characterized. Objective This study evaluates the efficacy of Rezum therapy in catheter-dependent patients, assesses treatment success rates, and identifies predictors of successful catheter independence. Methods We conducted a retrospective analysis of 597 patients who underwent Rezum therapy for BPH between 2019-2023, identifying 53 catheter-dependent patients (45 with indwelling catheters, 8 requiring clean intermittent catheterization). Voiding trials were attempted at one-month post-procedure, with follow-up stratified into three intervals: 3 months, 6-9 months, and 1-3 years. Univariable and multivariable regression modeling identified predictors of persistent urinary retention. Results Among the 53 patients, 45 had indwelling catheters while 8 required CIC. The majority of patients (90.5%, 48/53) had an American Society of Anesthesiology (ASA) score of 2 or 3, limiting them to procedures under local anesthesia or brief general anesthesia. Sexual function preservation was a priority for all ASA 1 patients (5/5) and approximately half of ASA 2 patients (6/13). Among the 11 sexually active patients, 90.9% (10/11) reported no change in erectile function at three months, with one patient reporting improvement. Regarding ejaculatory function, 81.8% (9/11) reported no changes, one patient reported improvement, and one patient experienced intermittent antegrade ejaculation. At one-month post-surgery, 47% of patients (25/53) achieved spontaneous voiding, including 24 patients with previous indwelling catheters and one patient with prior CIC. By three months, 60.4% of patients (32/53) were voiding spontaneously, comprising 30 patients who previously had indwelling catheters and 2 patients who had performed CIC. Among the 32 patients voiding spontaneously at 3 months, uroflowmetry was available for 18 patients, showing a median maximum flow rate (Qmax) of 12.8 ml/s (IQR: 10.5–16.4) and median post-void residual volume of 59 ml (IQR: 29–167). Quality of life significantly improved, with median IPSS-QoL scores decreasing from 5 (IQR: 4–5) preoperatively to 2 (IQR: 1–3) postoperatively (p&lt;0.001). At 6-9 months follow-up, 62.5% of patients (25/40) with documented visits remained catheter-free, while 8 patients continued CIC and 5 retained indwelling catheters. At the final follow-up period of 1-3 years, 69% of patients (17/25) remained catheter-free, with 6 patients performing CIC and 2 patients maintaining indwelling catheters. Multivariable analysis revealed that patients receiving more Rezum treatments had significantly higher odds of treatment success compared to those receiving fewer treatments (OR = 4.08, 95% CI: 1.12–14.8, p = 0.033). Additionally, larger prostate size was associated with increased odds of treatment response (OR = 1.015, 95% CI: 1.002–1.044, p = 0.042). Conclusions Rezum therapy represents a well-suited treatment option for catheter-dependent BPH patients, particularly those prioritizing sexual function preservation or limited to procedures under local anesthesia. The treatment success positively associated with the number of Rezum treatments administered and larger prostate size. Disclosure No

Abstract Introduction Inflatable penile prosthesis (IPP) implantation is a common and effective surgical treatment for erectile dysfunction. However, the presence of comorbidities and the use of anti-thrombotic therapy (AT) can complicate surgical decision-making. Due to the correlation between erectile dysfunction and cardiovascular disease, the preoperative comorbidities of surgical patients are important to examine. Objective The goal of this study was to assess the outcomes of IPP implantation in men on active AT therapy compared to a non-AT therapy cohort. Methods A retrospective analysis from 2015 to 2023 was conducted using data from three high-volume implant centers. The study focused on men who underwent three-piece IPP placement. Demographics, comorbidities, secondary procedures, drain information, and complications were recorded. The three centers each have different techniques and approaches to the surgery. Center 1 utilizes a penoscrotal approach, never places a drain, and places the reservoir in an ectopic location. Center 2 utilizes an infra-pubic approach, places a drain which remains in place for 3 days, and utilizes various reservoir locations depending on patient profile. Lastly, center 3 utilizes a penoscrotal approach, places a drain with removal when output is less than 50 mL over 8 hours, and places the reservoir in an ectopic location. Outcomes were analyzed using multivariate and univariate analysis. Results A total of 210 patients on active AT therapy and 128 non-AT patients were included. The AT and non-AT groups showed significant differences in baseline comorbidities, with the AT group exhibiting higher rates of cardiovascular disease, hypertension, and thrombosis (p&lt;0.05). Among patients on anti-thrombotic therapy, 27.6% required revision surgeries and had increased rates of ectopic reservoir placement compared to the non-AT group (p&lt;0.001). Despite these differences, there were no statistically significant variations in overall complication rates between the two groups. Drain output was notably higher in the AT cohort on postoperative days 1 (mean 110.5 cc vs 60 cc, p&lt;0.001) and 2 (mean 78 cc vs 20 cc, p&lt;0.001); however, hematoma rates remained comparable between both groups (p=0.667). Importantly, neither the type of anti-thrombotic therapy nor the surgical approach used appeared to influence postoperative outcomes. Eleven patients (5.2%) experienced complications in the AT arm and 5 patients (3.9%) experienced complications in the non-AT arm (p=0.793). Conclusions IPP implantation is feasible and safe in men on active anti-thrombotic therapy when performed in high-volume centers with appropriate perioperative management. Further studies with larger cohorts and longer follow-up are needed to refine protocols and determine long-term outcomes for these high-risk patients. Disclosure No