Tethered vagina syndrome: massive urine loss caused by bladder neck scarring cured by skin graft

Abstract

The bladder neck area of the vagina is known as the "zone of critical elasticity" (ZCE). Adequate vaginal elasticity at ZCE is required for the oppositely-acting muscles to independently close the distal urethra and bladder neck. Scarring at ZCE "tethers" the more powerful posterior muscles to the anterior muscles and the bladder neck is forcibly pulled open, resulting in massive urine loss. This condition is known as "tethered vagina syndrome" (TVS). In developed countries, the main cause of TVS is iatrogenic. Vaginal repairs, vaginal mesh, may cause scarring at ZCE and this directly links the oppositely-acting muscle forces. Over-elevated Burch colposuspensions may stretch the ZCE to the point where its elasticity is lost so the muscles can no longer function independently. The treatment is to dissect the vagina clear of the scarring and to insert a skin graft to the bladder neck to restore ZCE elasticity. In developing countries, extensive trauma to the vagina and bladder from obstructed childbirth can cause obstetric fistulas. In up to 40-50% of these women, there is ongoing massive urine loss after the fistula has been successfully closed. Performing a prophylactical skin graft during fistula closure if there is vaginal tissue deficit is proving to be revolutionary. In women with Goh type 4 fistula (n=45), 46% were cured (full dryness) against an expected 19%. The same operation can produce equally dramatic cures in women who continue to leak urine after successful fistula repair.

Keywords: Tethered vagina syndrome (TVS); fistula; massive urine loss; scarring; skin graft.

Figure 1

Urethral closure in normal (A) and scar induced situation (B). (A) Normal urethral closure in the female during coughing or straining. ZCE allows separate action of forward and backward vectors. (B) Mechanism of scar induced incontinence. During effort, “LP/LMA” vectors overcome the weaker “PCM” vector (weakness indicated by broken lines) to open out the urethra as per micturition. A Singapore flap, skin-on Martius, or other skin graft can cure or improve the massive incontinence by restoring elasticity at ZCE. ZCE, zone of critical elasticity; PUL, pubourethral ligament; PCM, pubococcygeus muscle; LP, levator plate; LMA, conjoint longitudinal muscle of the anus.

Figure 2

Scar at bladder neck area of the vagina. The scar “tethers” the anterior and posterior muscle forces, so that the urethra is forcibly pulled open on getting out of bed in the morning. Reused from Petros P. The female pelvic floor function, dysfunction and management according to the Integral Theory. 3^rd ed. Heidelberg: Springer Berlin; 2010. With permission from Peter Petros; retains ownership of the copyright.

Figure 3

2D transperineal ultrasound of tethered vagina syndrome. Left image: at rest; right image: minimal descent of the bladder neck on straining. The bladder neck and distal urethra are closed during straining. Reused from Petros P. The female pelvic floor function, dysfunction and management according to the Integral Theory. 3^rd ed. Heidelberg: Springer Berlin; 2010. With permission from Peter Petros; retains ownership of the copyright.

Figure 4

Augmentation of ZCE with a skin-on Martius graft restores independent movement of the vector forces. Reused from Petros P. The female pelvic floor function, dysfunction and management according to the Integral Theory. 3^rd ed. Heidelberg: Springer Berlin; 2010. With permission from Peter Petros; retains ownership of the copyright. LM, labium majus; G, graft sutured to bladder neck area of vagina to cover the tissue deficit; ZCE, zone of critical elasticity.

Figure 5

The mechanics of the tethered vagina. The scar tissue at ZCE tethers the more powerful posterior force to the weaker anterior force (arrows) forcibly opening the outflow tract, much as occurs in micturition, during actions which prolonged pelvic muscle contractions, such as getting out of bed in the morning, but driven mechanically, not neurologically. Reused from Petros P. The female pelvic floor function, dysfunction and management according to the Integral Theory. 3^rd ed. Heidelberg: Springer Berlin; 2010. With permission from Peter Petros; retains ownership of the copyright. ZCE, zone of critical elasticity; PUL, pubourethral ligament; PCM, pubococcygeus muscle; ATFP, arcus tendineus fascia pelvis; USL, utero sacral ligament; LP, levator plate; LMA, conjoint longitudinal muscle of the anus.

Figure 6

Augmentation of ZCE with a skin-on Singapore graft restores independent movement of the vector forces. The Singapore graft is taken lateral to the labium majus. Ureteric (white) and urethral (yellow) catheters are seen in situ. Reused with permission from Pelviperineology (11). ZCE, zone of critical elasticity.

Video S1

Video abstract.

Video S2

Andrew Browning discusses the principles behind using a skin-on flap for cure of continuing massive urine loss after successful obstetric fistula closure. By permission of Andrew Browning.