Scientific and technical advances in continence recovery following radical prostatectomy

Abstract

The advent of prostate-specific antigen screening has changed the global epidemiology of prostate cancer, with men being diagnosed with organ-confined cancer at a younger age. Radical prostatectomy with curative intent for these patients, while delivering excellent long-term survival outcomes, still has significant side effects, chiefly postprostatectomy incontinence. Increasing age, shorter pre- and post-operative membranous urethral length, anastomotic strictures, obesity, low surgeon volume, variations of surgical technique and previous prostate surgery have been reported as negative risk factors for delayed continence recovery and/or permanent incontinence following radical prostatectomy. Significant progress in elucidating the functional anatomy and physiology of the male continence mechanism from cadaveric and videourodynamic studies have enabled surgeons to propose innovative surgical techniques during radical prostatectomy for augmenting continence preservation and early return. These have included optimizing the preservation of urethral rhabdosphincter length; avoiding rhabdosphincter injury; posterior reconstruction of Denonvilliers' musculofascial plate; preservation of the bladder neck and internal sphincter; bladder neck intussusception; bladder neck mucosal eversion; preservation of the puboprostatic ligaments and arcus tendineus; and preservation of putative nerves supplying the continence mechanism. We review the scientific and technical advances in continence recovery following radical prostatectomy, identify the key principles undergirding early return of continence, highlight various treatment strategies for early and refractory postprostatectomy incontinence and describe our experience with a paradigm of these unified key principles. Increasing application of these principles in computer-aided (robotic), minimally invasive and minimal-access (i.e., single-port or natural orifice transluminal) approaches will hopefully enable patients to derive maximal benefit from curative prostatectomy while experiencing early return of continence in the not too distant future.

Urinary Incontinence

“…Urinary continence in men depends on adequate bladder function as well as a competent urethral sphincter [ 42,43 ] . The urethral sphincter mechanism involves two functionally separate units: the proximal urethral (internal) sphincter and the distal (external) urethral sphincter [ 43 ] .…”

“…80.2 , the components of the distal urethral complex include the prostatomembranous urethra, the omega-shaped external rhabdosphincter that surrounds the prostatomembranous urethra and is de fi cient posteriorly, the paraurethral musculature (e.g., levator ani), and the pelvic fl oor connective tissues [ 44 ] . The external urethral rhabdosphincter is comprised of both outer striated, mostly slow-twitch type 1, muscle fi bers that provide continence through tonic contraction and inner smooth muscle fi bers [ 42,45 ] . Moreover, the levator ani and pelvic fl oor musculature are comprised of both type 1 and fasttwitch type 2 fi bers, the latter necessary for maintaining continence during acute rises in intra-abdominal pressure [ 42,45,46 ] .…”

“…The external urethral rhabdosphincter is comprised of both outer striated, mostly slow-twitch type 1, muscle fi bers that provide continence through tonic contraction and inner smooth muscle fi bers [ 42,45 ] . Moreover, the levator ani and pelvic fl oor musculature are comprised of both type 1 and fasttwitch type 2 fi bers, the latter necessary for maintaining continence during acute rises in intra-abdominal pressure [ 42,45,46 ] . The interaction between these two mechanisms provides both passive and active continence after prostatectomy.…”

“…For this reason, reconstruction of the posterior rhabdosphincter to restore anatomic relations is one approach to improve urinary outcomes [70][71][72] . Based on an improved understanding of the male continence mechanism, anatomic restoration of the vesicourethral junction has also been postulated to improve early continence outcomes [ 42,73,74 ] . Moreover, the fascial investments of the rhabdosphincter fuse anteriorly with the pubourethral, i.e., puboprostatic ligamentsextensions of the arcus tendineus, and provide stabilization to the continence mechanism [ 42,49 ] .…”

“…Based on an improved understanding of the male continence mechanism, anatomic restoration of the vesicourethral junction has also been postulated to improve early continence outcomes [ 42,73,74 ] . Moreover, the fascial investments of the rhabdosphincter fuse anteriorly with the pubourethral, i.e., puboprostatic ligamentsextensions of the arcus tendineus, and provide stabilization to the continence mechanism [ 42,49 ] . This has led some to implicate transection of the puboprostatic ligaments in postprostatectomy incontinence [ 49,75,76 ] .…”