**6. Normal micturition and abnormal emptying of the bladder**

Micturition is another complex mechanism that has to be understood when performing pelvic floor surgery. Thus, not only sphincter relaxation and detrusor contraction have to be taken into consideration. EMG-measurements in the posterior fornix have demonstrated commencement of muscle contraction prior to commencement of voiding (Petros 2010). Radiologically, it was shown that the anterior vaginal wall is stretched and moved backward and downward during micturition (figures 4b). The bladder also moves backward and downward and the proximal urethra funnels (figure 4a). This can only be explained by active muscle contractions of levator plate (LP) and longitudinal muscle of anus (LMA). Relaxation of the forward force (PCM) and relaxation of urethral sphincter allows the backward and downward forces to open up the outflow tract (figure 4c)

Fig. 4. Normal micturition. a) Lateral xray, same patient as fig. 3. During micturition, the bladder and vagina move backwards and downward, opening out the posterior urethral wall. b) Superimposed lateral xray.s At rest (unbroken lines) and micturition (broken lines) vascular clips placed at midurethra "1", bladder neck "2" and bladder base "3". c) Muscle actions during micturition . PCM relaxes. This allows the posterior muscle forces LP/LMA (red arrows) to stretch vagina and posterior urethral wall backwards/downwards to open out the outflow tract. Same labelling as fig. 3. (From P Petros 2010, by permission).

The posterior muscles (LP and LMA) only contribute in opening the bladder neck and urethra when the connective tissue architecture and its insertion points are intact in a way that they can pull normally (see figure 1). If the uterosacral ligaments are loose (insertion points of the LMA) or a cystocele is present the posterior forces cannot pull normally, the muscles are shortened or overstretched and have reduced force. Even a minor degree of prolapse can be the cause of defective micturition. Kinking of the urethra by prolapse can also be a cause of abnormal emptying of the bladder. A location of the tape too high up the bladder neck or proximal urethra as well as anterior fixation of the bladder neck after colposuspension can disturb funnelling of the urethra.

#### **7. Stability at the bladder base by a tensioned vaginal wall, urgency and frequency**

In their first publication of the "Integral theory" Petros and Ulmsten (1990) stated that "symptoms of stress and urge derive mainly from laxity in the vagina or its supporting ligaments, a result of altered collagen/elastin". Following their publication, evidence was

Micturition is another complex mechanism that has to be understood when performing pelvic floor surgery. Thus, not only sphincter relaxation and detrusor contraction have to be taken into consideration. EMG-measurements in the posterior fornix have demonstrated commencement of muscle contraction prior to commencement of voiding (Petros 2010). Radiologically, it was shown that the anterior vaginal wall is stretched and moved backward and downward during micturition (figures 4b). The bladder also moves backward and downward and the proximal urethra funnels (figure 4a). This can only be explained by active muscle contractions of levator plate (LP) and longitudinal muscle of anus (LMA). Relaxation of the forward force (PCM) and relaxation of urethral sphincter

allows the backward and downward forces to open up the outflow tract (figure 4c)

a) b) c) Fig. 4. Normal micturition. a) Lateral xray, same patient as fig. 3. During micturition, the bladder and vagina move backwards and downward, opening out the posterior urethral wall. b) Superimposed lateral xray.s At rest (unbroken lines) and micturition (broken lines) vascular clips placed at midurethra "1", bladder neck "2" and bladder base "3". c) Muscle actions during micturition . PCM relaxes. This allows the posterior muscle forces LP/LMA (red arrows) to stretch vagina and posterior urethral wall backwards/downwards to open

The posterior muscles (LP and LMA) only contribute in opening the bladder neck and urethra when the connective tissue architecture and its insertion points are intact in a way that they can pull normally (see figure 1). If the uterosacral ligaments are loose (insertion points of the LMA) or a cystocele is present the posterior forces cannot pull normally, the muscles are shortened or overstretched and have reduced force. Even a minor degree of prolapse can be the cause of defective micturition. Kinking of the urethra by prolapse can also be a cause of abnormal emptying of the bladder. A location of the tape too high up the bladder neck or proximal urethra as well as anterior fixation of the bladder neck after

out the outflow tract. Same labelling as fig. 3. (From P Petros 2010, by permission).

**7. Stability at the bladder base by a tensioned vaginal wall, urgency and** 

In their first publication of the "Integral theory" Petros and Ulmsten (1990) stated that "symptoms of stress and urge derive mainly from laxity in the vagina or its supporting ligaments, a result of altered collagen/elastin". Following their publication, evidence was

colposuspension can disturb funnelling of the urethra.

**frequency** 

**6. Normal micturition and abnormal emptying of the bladder** 

increasingly found that supported their claim that a correlation between the prolapse and an overactive bladder exists (de Boer et al. 2010).

Figures 2, 3b and 5 show that the bladder lies on the vaginal wall. With effort the posterior vaginal wall is orientated horizontally and the bladder lies on this part of tensioned vaginal wall (figure 3b), which acts as a "trampoline". The vagina is attached to the pelvic rim by the uterosacral ligaments posteriorly, the arcus tendineus and the cardinal ligaments laterally as well as the pubourethral ligament anteriorly. Anterior and posterior muscle forces (red arrows in figure 5) add to tension the vaginal wall. While the slow twitch fibres are active when at rest, the fast twitch fibres are active during effort. At the bladder base stretch receptors are present which are connected by afferent nerves to the cortex (Wyndaele et al. 2008, Everaerts et al. 2008, Petros & Ulmsten 1990). Efferent nerves can activate the pelvic floor musculature (figure 5).

Fig. 5. Stability at the bladder base by a tensioned vaginal wall "Trampoline Analogy". (From P Petros 2010, by permission).

Petros and Ulmsten (1993) postulated that urgency could lead to a premature activation of the micturition reflex. A lax vagina at the anterior, middle or posterior zone reduces the

The Role of Altered Connective Tissue in the Causation of Pelvic Floor Symptoms 13

mechanism is similar to that of bladder neck closure. Directional muscle forces stretch the rectum backwards and downwards around an anus firmly anchored by the puborectalis muscle. Anorectal closure occurs when the backward muscle forces of LP and LMA stretch the rectum around the anus, which is anchored by PRM-contraction. Upon comparing Figure 3b with Figure 3a, the rectum above the anal canal has been markedly angulated (and closed) by muscle actions during effort. Upon relaxation of PRM, LP/LMA vectors open out

Fecal incontinence can occur when connective tissue at the anterior zone is loose. Then the insertion points of the puborectalis muscle are dislocated and the muscle is weak. Furthermore, the anterior insertion points of the levator plate are loose and the muscle is

When connective tissue at the posterior zone is loose, the muscles also cannot act optimally and fecal incontinence can occur. Lax uterosacral ligaments can explain rectal intussusception and obstructive defecation. The levator plate cannot tension the rectovaginal fascia. The perineal body is an important anchoring point and, if loose, it can contribute to fecal incontinence and obstructive defecation (Petros 2010, Abendstein and

Many patients with vaginal vault prolapse or uterus prolapse report pelvic pain, a low abdominal dragging pain which occurs mainly in an upright position and is generally relieved in a lying position. This pain may be associated with vulvodynia. Both types of pain have been temporarily relieved by injection of local anaesthetic into the uterosacral ligaments (Bornstein et al 2005, Petros et al 2004), supporting the hypothesis that this pain is a referred pain arising from the inability of lax uterosacral ligaments to support the nerves running along the ligament (figure 7). These nerves are stretched by gravity or during intercourse to cause pain. This pain is almost invariably associated with other symptoms deriving from posterior zone laxity, Figure 8. In a recent study, restoration of uterosacral ligament tension using a posterior tensioned sling showed improvement in posterior zone symptoms as follows: nocturia >2/night 83%; urge-incontinence >2/day 78%; abnormal emptying, 73% ; pelvic pain, 86% fecal incontinence, 87% (Petros PEP,

**11. The association of pelvic floor dysfunctions and different zones of** 

that had different forms and degrees of descensus/prolapse of the vaginal wall.

The three zones of connective tissue looseness (see above) are associated with different symptoms. Petros (2010) developed the diagnostic algorithm (Figure 8) through considering the pathophysiology of dysfunctions and through practical experiences with the patients

Many symptoms are associated with these different forms of descensus/prolapse: stress urinary incontinence, abnormal emptying of the bladder, urgency and frequency, nocturia,

**connective tissue looseness at the pelvic floor (figure 8)** 

faecal incontinence, obstructed defecation and pelvic pain.

the anal canal for evacuation (broken lines, Fig2)

weak and the anorectal closure is weak, also.

Petros 2008).

**10. Pelvic pain** 

Richardson PA, 2010)

tension of the vagina below the bladder base, the stretch receptors can be activated by afferent nerves, the cortex gets the information of full bladder and this creates the sensation of urge. Prematurely the micturition reflex can be activated and even urge incontinence can occur.
