3D CT Urethrography With Cinematic Rendering (3DUG): A New Modality for Evaluation of Complex Urethral Anatomy and Assessment of the Postoperative Phalloplasty Urethra

Objective: To develop an imaging modality for the postoperative phalloplasty urethra. Despite high urologic complication rates after masculinizing genital surgery, existing methods for postsurgical evaluation after phalloplasty have drawbacks. Fluoroscopic studies like the retrograde urethrogram have limitations like user-dependence and need for meticulous positioning but also are inadequate for the evaluation of the anatomically complex postphalloplasty urethra. We developed a novel protocol utilizing CT urethrography with 3D reconstruction using cinematic rendering (3DUG) for neo-urethral imaging. Materials and Methods: Patients who underwent 3DUG after either phalloplasty, metoidioplasty, or prior to revision surgery were included. Low-dose imaging protocols were used to avoid any increases in radiation exposure. The first iteration of our protocol utilized retrograde contrast administration via the penile urethra, whereas the second iteration of our protocol utilized an antegrade technique with contrast instillation via the suprapubic catheter and a voiding scan. Imaging was initially obtained according to symptoms and then per protocol at 3 weeks after urethral lengthening. Results: Twenty-six patients were included in the series. Among postoperative phalloplasty patients imaged for symptoms, contrast extravasation/fistula was identified in 5 (63%), vaginal remnant in 3 (38%), and stricture in 2 (25%) compared to 5 (45%), 1 (9%), and zero respectively for patients imaged routinely. When intervention was required, operative findings correlated to anatomy on imaging. Conclusion: We present a new protocol for the use of 3D CT urethrography with cinematic rendering for neo-urethral reconstruction. This technique has the potential to improve surgical planning and surveillance of urologic complications in postphalloplasty patients.