Three-dimensional mapping and comparative analysis of the distal human corpus cavernosum and the inflatable penile prosthesis

Abstract

The intricate anatomy of the corpus cavernosum in both the flaccid and tumescent state has not been fully elucidated. We report our experience using a three-dimensional (3D) scanner to reconstruct cadaveric casts and compare them with 3D images of two prototypes of penile prosthesis. Two different models of the Titan Coloplast inflatable penile prosthesis were analyzed using a 3D scanner. The first was the standard model and the second was a newer model with a rounder silicone tip. Two cadaveric phalluses were harvested using Smooth-Cast 300Q polyurethane molding. The molds were excised and scanned along side the penile prosthesis. 3D scans were completed and analyzed using Leios Mesh software, and GOM Inspect software. The 3D scans demonstrated the mean human corporal radii 2 mm from the distal tip to be 36.51 mm (36.01-37.0 mm), which is an obtuse angle. The standard Titan penile prosthesis spherical radius at the same level was 202.52 mm, while the new silicone tip prosthesis had a radius of 139.33 mm. 3D mapping further demonstrated the trajectory of the cavernosa appeared curvilinear and the distal ends appeared blunt. The use of cadaveric cavernosal molds in combination with the 3D scanner allowed us to accurately image the corpus cavernosum for the first time. Our findings suggest that anatomically accurate corporal tips appear to be relatively blunt and that the new Titan silicone tip penile prosthesis more closely resembles the human corporal tip.

Technological Improvements in Three-Piece Inflatable Penile Prosthesis Design over the Past 40 Years

“…In 2000, a reservoir lockout valve was added to prevent autoinflation, reducing the autoinflation rate from 11% in patients with the original reservoir to 1.3% in those with a lockout valve‐equipped reservoir [34]. Additional modifications have included the addition of RTEs to facilitate prosthesis size adjustment, twist‐on RTEs to strengthen the connection between the RTE and the cylinder, a one‐touch deflation valve (2008), a zero‐degree junction between the cylinders and tubing to facilitate intracorporal cylinder placement (2012) [35], and soft molded cylinder tips that more closely approximate human anatomy (2012) [36]. The development of the reservoir lockout valve and flat reservoirs in particular has contributed to the early success and feasibility of more recent submuscular surgical placement techniques.…”

Comprehensive assessment of cavernosography with 320-row dynamic volume CT versus conventional cavernosography in erectile dysfunction patients caused by venous leakage

“…Chen et al introduced ultrasonography as a method of assessment for vasculogenic impotence in 1985 and prior studies has proved ultrasound a major tool applied in the vascular differentiation process in ED [ 16 , 17 ]. In addition to ultrasounds, cavernosography has also been used by urologists to produce some of the earliest images taken of erect corpus cavernosum [ 10 ]. However, most venous vasculatures are covered in penile venous distribution when observed under ultrasonography, while conventional pharmaco-cavernosography only reveals a small portion of the leaky deep dorsal vein and fails to display either the para-arterial veins (PAVs) or the cavernosal veins (CVs) [ 8 ].…”

“…The obstruction of visualization of these structures also makes it difficult to show the origin of the veins through radioscopy [ 9 ]. With new advancements made in medical imaging technology, like computed tomography (CT) and also magnetic resonance imaging (MRI), more knowledge and information about the corpus cavernosum has been obtained [ 10 ]. Currently, improvements in the CT scan from 64 to 320 slice provide us with a higher resolution and much more detailed structure images, allowing for superior visualization of the internal penile tissue [ 11 ].…”

Penile implants: a look into the future

“…The silicone tipped Titan penile prosthesis spherical radius at the same level was 3.42 mm while the tip of the AMS prosthesis had a radius of 3.11 mm. Additionally, it was found that human corpora had a curvilinear trajectory with blunt ends ( 41 ). The same group later reported that AMS and Coloplast devices were similar when compared ( 42 ).…”