Department of Urology, Mayo Clinic, Rochester, MN 55905, United States of America.
Citations 2
Reverberant wavefield characterization and directional filtering for penile vibro-elastography: a pilot feasibility study in post-prostatectomy erectile dysfunction
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.
New findings regarding predictors of Poor Corporal Integrity in Penile Implant Recipients: A Multicenter International Invesigation
Objectives To evaluate the pre‐ and intraoperative variables that impact the integrity of the corporal bodies over time after inflatable penile prosthesis (IPP) placement, as predictors of intraoperative corporal perforation and delayed cylinder complications have not been well characterized. Patients and Methods We retrospectively reviewed a 16‐centre multi‐institutional database of IPP surgeries performed by experienced implanters from 2016 to 2021. Poor corporal integrity (PCI) was defined as intraoperative (iPCI) corporal complications or postoperative (pPCI) corporal complications. Multivariable analysis was performed to identify independent predictors of PCI, iPCI, and pPCI. Primary outcomes included intra‐ and postoperative corporal complications. Results We identified 5153 patients for analysis from 5406 IPP cases, finding 152 (2.95%) cases of PCI. On multivariable analysis, predictors of PCI included revision IPP surgery (odds ratio [OR] 8.16, 95% confidence interval [CI] 5.15–12.92; P < 0.001), sequential dilatation (OR 2.12, 95% CI 1.32–3.39; P = 0.002), coronary artery disease (CAD)/peripheral vascular disease (PVD) (OR 1.81, 95% CI 1.18–2.77; P = 0.006), older age (OR 1.02, 95% CI 1.01–1.04; P = 0.013), and corporal scarring (OR 1.58, 95% CI 1.0–2.5; P = 0.049). Predictors of iPCI included revision IPP surgery (OR 7.34, 95% CI 4.18–12.88; P < 0.001), corporal scarring (OR 2.77, 95% CI 1.64–4.69; P < 0.001), radiation therapy (OR 2.25, 95% CI 1.0–5.04; P = 0.049), and older age (OR 1.03, 95% CI 1.0–1.05; P = 0.025). Revision IPP surgery (OR 7.92, 95% CI 3.69–17.01; P < 0.001), sequential dilatation (OR 3.4, 95% CI 1.61–7.19; P = 0.001), CAD/PVD (OR 2.98, 95% CI 1.56–5.72; P = 0.001), and history of priapism (OR 3.59, 95% CI 1.08–11.99; P = 0.038) were predictive of pPCI. Conclusion Coronary artery disease/PVD, being of older age, having corporal scarring, undergoing IPP revision surgery and sequential dilatation were predictive risk factors for complications associated with PCI. Identifying patients who are at risk of having PCI may improve patient‐specific counselling, consideration of referral to more experienced implanters, and surgical planning to potentially promote longer‐term device viability.