Pelvic magnetic resonance imaging angioanatomy of the arterial blood supply to the penis in suspected prostate cancer patients

Clinical Anatomy of the Superficial Preprostatic Vein and Accessory Pudendal Artery in Robot-Assisted Radical Prostatectomy

Purpose: We herein describe the superficial preprostatic vein (SPV) anatomy and determine its relationship with the accessory pudendal artery (APA). Materials and Methods: We reviewed 500 patients with localized prostate cancer who underwent conventional robot-assisted radical prostatectomy between April 2019 and March 2023 at our institution. SPV was defined as "any vein coming from the space between the puboprostatic ligaments and running within the retropubic adipose tissue anterior to the prostate toward the vesical venous plexus or pelvic side wall." While APA was defined as "any artery located in the periprostatic region running parallel to the dorsal vascular complex and extending caudal toward the anterior perineum." The intraoperative anatomy of each SPV and APA was described. Results: SPVs had a prevalence rate of 88%. They were preserved in 252 men (58%) and classified as I-, reversed-Y (rY)-, Y-, or H-shaped (64%, 22%, 12%, and 2%, respectively) based on their intraoperative appearance. Overall, 214 APAs were found in 142 of the 252 men with preserved SPV (56%; 165 lateral and 50 apical APAs in 111 and 41 men, respectively). SPVs were pulsatile in 39% men perhaps due to an accompanying tiny artery functioning as a median APA. Pulsations seemed to be initially absent in most SPVs but become apparent late during surgery possibly due to increased arterial and venous blood flow after prostate removal. Pulsations were common in men with ≥1 APA. Conclusions: This study, which described the anatomical variations in arteries and veins around the prostrate and their preservation techniques, revealed that preserving this vasculature may help preserve postprostatectomy erection. ClinicalTrials: The Clinical Research Registration Number is 230523D.

Post-Traumatic High-Flow Priapism: Accessory Pudendal Origin of Cavernosal Artery From External Iliac Artery - A Case Report

High-flow priapism is an uncommon condition typically resulting from penile or perineal trauma, due to laceration of cavernosal artery. We present a case of 24-year-old male who presented with post-traumatic painless priapism. Ultrasound showed hematoma with arterio-cavernosal fistula. On CT Angiogram, the cavernosal artery was seen arising from accessory pudendal artery, which arose from inferior epigastric artery (IEA), branch of external iliac artery (EIA). Catheter angiogram of EIA showed fistulous communication at the base of the penis from a branch of IEA. Selective embolisation of the artery was done using 33% glue (n-butyl cyanoacrylate). Post embolisation, no residual filling of the fistula and partial detumescence of penis was noted. Transarterial embolisation is usually preferred as first line of management in high-flow fistulous priapisms.

Utility of dynamic MRA in the evaluation of male erectile dysfunction

PURPOSE

To assess the efficacy of time-resolved MR angiography (MRA) in evaluating penile vasculature in patients with clinically suspected vascular anomalies contributing to their erectile dysfunction correlating with penile doppler ultrasound (PDUS) findings and clinical outcomes after surgical intervention.

METHODS

Men (n = 26) with signs of early vascular shunting on PDUS underwent time-resolved, contrast-enhanced (0.1 mMol/kg gadobutrol at 1 ml/s followed by saline flush) 3-dimensional spoiled gradient echo T1-weighted MRA sequence performed over 3 min with 4.6 s frame rate after intracavernosal injection of an erectogenic agent. Additional T1- and T2-weighted sequences were performed for anatomic co-localization and tissue characterization. MRA images were evaluated for early filling of draining veins as well as arteriovenous malformations and fistulas and correlated with findings at surgery.

RESULTS

29 MRA examinations on 26 patients (mean age 39 years) demonstrated abnormal early venous drainage (n = 22) as well as diminutive/delayed cavernosal enhancement (n = 3), incomplete tumescence (n = 2), and combined arterial inflow/venous outflow disease (n = 1). The MRA had a concordance of 85.2% at determining the presence, or lack thereof of a shunt/AVM when compared to PDUS.

CONCLUSIONS

Time-resolved MRA allows for both temporal and spatial resolution with visualization of both arterial and venous abnormalities which may be suggested with a screening PDUS examination. This technique allows us to provide detailed anatomic information prior to any surgical intervention.

Contemporary and Novel Imaging Studies for the Evaluation of Erectile Dysfunction

Traditionally, it was thought that the pathogenesis of erectile dysfunction (ED) can be divided into psychological and organic factors. However, recent literature supports the development and progression of ED due to multidimensional alterations of a complex interplay of central and peripheral systems, from neural cognitive and efferent networks to loco-regional neuro-hormonal factors which are responsible for impaired penile vascular hemodynamics and ensuing lack of, or suboptimal, blood flow into the penis and/or veno-occlusive dysfunction. It is recognised that ED is strongly correlated with cardiovascular health and published clinical guidelines advocate screening for cardiovascular and metabolic risk factors in men presenting with ED. Over the past few decades, various imaging modalities have been developed and utilised to provide objective evaluation for ED to better characterise the state of penile health and exclude psychogenic components. The following article evaluates current and emerging imaging diagnostic tools for ED.

Development of a Three-dimensional Surgical Navigation System with Magnetic Resonance Angiography and a Three-dimensional Printer for Robot-assisted Radical Prostatectomy

We sought to develop a surgical navigation system using magnetic resonance angiography (MRA) and a three-dimensional (3D) printer for robot-assisted radical prostatectomy (RARP). Six patients with pathologically proven localized prostate cancer were prospectively enrolled in this study. Prostate magnetic resonance imaging (MRI), consisting of T2-weighted sampling perfection with application-optimized contrasts using different flip-angle evolutions (SPACE) and true fast imaging with steady-state precession (true FISP), reconstructed by volume rendering, was followed by dynamic contrast-enhanced MRA performed with a volumetric interpolated breath-hold examination (VIBE) during intravenous bolus injection of gadobutrol. Images of arterial and venous phases were acquired over approximately 210 seconds. Selected images were sent to a workstation for generation of 3D volume-rendered images and standard triangulated language (STL) files for 3D print construction. The neurovascular bundles (NVBs) were found in sequence on non-contrast images. Accessory pudendal arteries (APAs) were found in all cases in the arterial phase of contrast enhancement but were ill-defined on non-contrast enhanced MRA. Dynamic contrast-enhanced MRA helped to detect APAs, suggesting that this 3D system using MRI will be useful in RARP.