A three dimensional nerve map of human bladder trigone

Abstract

Aim: Central efferent and afferent neural pathways to and from the human urinary bladder are well-characterized, but the location and arborization of these nerves as they traverse the serosa, muscularis, and urothelial layers are not clearly defined. The purpose of this study was to create a three dimensional map of the innervation of the human bladder trigone from the extrinsic perivesical adventitial nerve trunks to the urothelium.

Methods: A male and a female human bladder were harvested from fresh frozen cadavers and fixed in formalin. The bladder neck and trigone region were serially sectioned (5 μm) and every 20th slide was stained (S100), scanned and aligned to create 3D maps.

Results: Nerve penetration into the detrusor muscle occurs with the highest frequency at the bladder neck and interureteric ridge. Nerves traveling parallel to the bladder lumen do so in the adventitia, beyond the outer border of detrusor. In females, the depth of these nerve bands is uniform at 0.7-1.7 cm below the luminal surface, the outer limits of which include the anterior vaginal wall. In the male, depth is more variable owing to detrusor hypertrophy with the minimum depth of nerves approximately 0.5 cm near the interureteric ridge and over 1 cm near the bladder neck.

Conclusions: Myelinated neural pathways traversing in the human bladder in the region of the trigone have a discreet regional density. This 3D map of trigonal innervation may provide guidance to more precisely direct therapies for urinary incontinence or pelvic pain. Neurourol. Urodynam. 36:1015-1019, 2017. © 2016 Wiley Periodicals, Inc.

Keywords: bladder; botox; botulinum; continence; human; innervation; map; nerves.