Monday, 16 March 2015

Urinary Incontinence Overview

Urinary incontinence Overview: 

Definition

Is the complaint of involuntary leakage of urine.
It results from failure to store urine during the filing phase of the bladder due to the following

1- Detrusor dysfunction
2- Urethral sphincter abnormalities 
3- Anatomical abnormalities 

It is usually urethral however it could be extra-urethral (ectopic ureter, vesico-vaginal fistula) 

Prevalence

It affects 3.5 million people in the UK. 
It is twice as common in females compared to males. 
Up to 20% of females above the age of 65 suffer from urinary incontinence and 10% of males at the same age. 

Classification

1- Stress urinary incontinence (SUI) 
Involuntary leakage of urine on effort, exertion, sneezing, or coughing. 

It is due to the following: 
a- Hypermobility of the bladder base (Urethral hypermobility) 
b- Pelvic floor deficiency
c- Intrinsic urethral sphincter deficiency (ISD)

(These are not mutually exclusive) 


It is categorized by Blaivas into 

a- Type 0: no clinical signs of incontinence 
b- Type 1: leakage during stress with less than 2 cm descent of the bladder base below the upper border of the symphsis pubis 
c- Type 2: leakage on stress with more than 2 cm descent of the bladder during stress (2a) or even without stress i.e. permanently (2b) 
d- Type 3: bladder neck and proximal urethra are open at rest regardless of descent, this is also known as (ISD) 

2- Urge urinary incontinence (UUI) 

Involuntary urinary leakage immediately preceded by urgency. 
It is due to an overactive detrusor muscle. 

3- Mixed urinary incontinence (MUI) 
Combination of both SUI and UUI

4- Overflow incontinence 
It happens in men with chronic urinary retention and degree of detrusor failure, the bladder is abnormally distended with large residual volumes. 30% develop renal failure. 

5- Nocturnal enuriesis: 
Loss of urine during sleep.
can be further classified into 
primary types (never dry for longer than 6 mo period) 
secondary (re bed wetting after being dry for at least 6-12 months) 
in adult it could be overflow incontinence. 

6- post micturition dribble:
In men due to pooling of urine in the bulbous urethra after voiding. 

7- continuous incontinence 
8- insensible incontinence 
9- coital incontinence 



Risk factors for UI

1- Female
2- Caucasian more than afro-carribeans
3- Neurological disorders (SCI, Stroke, MS, Parkinsons)
4- Anatomical disorders (vvf, ectopic ureters, urethral diverticulum)
5- Childbirth and pregnancy
6- Pelvic surgery (RPhttps://www.youtube.com/watch?v=SrFIbzqBPRc, TAH, TURP) 
7- Rx 
8- Diabetes 

Promoting factors 

1- Smoking (coughing increases pressure) 
2- Obesity
3- UTI
4- Increase fluid intake 
5- Medications (alpha blockers) 
6- Aging, poor nutrition, cognitive deficits, poor mobility
7- Oestrogen deficiency

Pathophysiology

1- Bladder abnormalities 

a- Detrusor overactivity: 
involuntary bladder contractions during the filling phase this could be either 

  • Neuropathic 
  • Idiopathic 
many hypothesis exist for DO: 

  • Myogenic: partial denervation of the detrusor 
  • Neurogenic: disruption of primary neural control in muscle cells 
  • Integrative hypothesis: abnormal or exaggerated peripheral autonomic activity within the peripheral myovesical plexus (intramural ganglia and interstitial cells) http://www.ncbi.nlm.nih.gov/pubmed/11502339

b- Low bladder compliance: 

decreased volume-to-pressure relationship due to 
alterations in elastic properties of the bladder wall, possible causes 


2- Urethral and sphincter abnormalities 

a- Urethral hypermobility: 

A rotational descent of the bladder neck and proximal urethra during increases in intra-abdominal pressure and leakage of urine if the urethra opens concomitantly.It’s due to weakness of pelvic floor support. 

b- Intrinsic sphincter deficiency (ISD): 

An intrinsic malfunction of the sphincter, regardless of its anatomical position. (Type III SUI) (bladder neck and proximal urethra are open at rest regardless of descent)

Causes include: 

  • Inadequate urethral compression (SAMRA, urethral surgery, ageing, menopause, radical pelvic surgery, anterior spinal artery syndrome
  • Deficient urethral support (4 Ps, Pelvic floor weakness, parity, pelvic surgery, post menopause
  • Damage to the urethral sphincter in males (RP, TURP, Rx) https://www.youtube.com/watch?v=SrFIbzqBPRc

I conclude that pelvic floor weakness can cause both ISD and urethral hypermobility.

Theories for the pathogenesis of SUI include; 

  • Integral theory: laxity of anterior vaginal wall and pubourethral ligaments, causing bladder neck hypermobility. 
  • Hammock hypothesis: failure of urethral support by the endopelvic fascia and vaginal wall. 

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