NEUROUROLOGY & FEMALE UROLOGY

What Are the Supportive Structures of the Female Urethra?
Fritsch H, Pinggera GM, Lienemann A, Mitterberger M, Bartsch G, Strasser H
Institute of Anatomy and Histology, University of Innsbruck, Innsbruck, Austria
Neurourol Urodyn. 2006; 25: 128-34

• Aims: Female stress urinary incontinence is thought to result from impairment of the connective tissue “ligaments” of the urethra. Surgical repair of female incontinence mainly involves fixation of the urethra to the pubic bone or other surrounding structures. In the present anatomical-radiological study, the anatomy of the connective tissue structures around the female urethra was investigated to determine the anatomical structures that support the urethra and the rhabdosphincter.
• Materials and Methods: The topography of the anterior compartment of the female pelvis was studied in serial sections and one anatomical preparation of 30 female fetuses and of six adult females. The pelves of 29 female fetuses were processed according to plastination histology technique. The pelves of the six adult specimens were processed according to sheet plastination technique. In addition, the anatomical findings were compared with MR images of 41 adult female volunteers.
• Results: The ventro-lateral aspect of the urethra remains free of fixating ligaments throughout its pelvic course. Ventro-laterally the urethra is enclosed by the ventral parts of the levator ani, its fasciae and a ventral urethral connective tissue bridge connecting both sides. Dorsally, the urethra is intimately connected to the wall of the vagina.
• Conclusions: The female urethra has no direct ligamentous fixation to the pubic bone. Urethral continence after pregnancy and childbirth may be explained by a widening of the hiatus of the levator ani or the anterior vaginal wall, resulting in overstretching of the ventral urethral connective tissue bridge or the disruption of the fixation between urethra and vagina.
  
  
• Editorial Comment
  The authors analyze the anatomy of the female urethra with regards to the support of the urethra and rhabdosphincter. This was accomplished through analysis of the pelves of 30 female fetuses and 6 female adults. The authors find that there is no pubourethral ligament attaching the urethra to the pubic bone; instead the tissues attaching the pubic bone to the bladder neck are mostly tissue containing smooth muscle cells. In addition, the dorsal end of the rhabdosphincter is connected at its dorsal end through a strong connective tissue fixation to the ventral wall of the vagina. The neurovascular bundles are identified in the dorsal lateral pelvic wall in the ventral lateral aspects of the urethra.
  This excellent article is extremely well written with beautiful anatomical pictures. That the investigators were not able to find the existence of any true pubourethral ligaments helps explain the ability of a patient to continue with urinary continence after a transvaginal urethrolysis, especially one utilizing the suprameatal transvaginal technique (1). That the authors found that the neurovascular bundles ran in the dorsal lateral pelvic wall on the lateral and ventral aspects of the urethra may explain a potentiality for sexual dysfunction after formal urethrolysis. There is an excellent discussion with regards to 3 supportive structures of the urethra and rhabdosphincter, which were identified, and the pathologic effects on same, which may lead to voiding dysfunction.
  Reference
  1. Petrou SP, Brown JA, Blaivas JG: Suprameatal transvaginal urethrolysis J Urol. 1999; 161: 1268-71.

Dr. Steven P. Petrou
Associate Professor of Urology
Associate Dean, Mayo Clinic College of Medicine
Jacksonville, Florida, USA