Medical maps: Urogynaecology

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Urogynaecology is a speciality dedicated to treat pelvic floor dysfunction which can manifest as:

  • Urinary incontinence – involuntary leakage of urine
  • Pelvic organ prolapse – an organ in the pelvis slips down and bulges into the vagina

These problems are common and massively impact quality of life.

In this post I’ll talk about the symptoms and pathology, but also the diagnosis and treatment because this is where a lot of the confusion lies in this topic.

Urinary incontinence

Physiology of normal continence

Understanding the physiology of normal continence is critical before we can understand urinary incontinence.

There are two important continence mechanisms; a problem with either of these mechanisms can result in urinary incontinence:

  • Sphincters:
    • Internal urethral sphincter comprised of smooth muscle
      • Tonically contracted with sympathetic nervous system
      • Relaxes with parasympathetic input during urination
    • External urethral sphincter comprised of skeletal muscle (fibres of pelvic floor muscles)
      • Secondary sphincter, controlling flow through the urethra
    • The sphincters can be damaged directly by surgery, or can lose function due to nerve damage
  • Transmission of intra-abdominal pressure:
    • Increases in pressure are transmitted to the bladder, but also the proximal urethra, preventing leakage – probably the most important mechanism
    • Transmission of intra-abdominal pressure can fail if the urethra is hypermobile and moves inferiorly – associated with multiple vaginal births, low oestrogen states e.g. post-menopause, chronic cough and surgery
IMG_0940

Sagittal view of the non-gravid female pelvis. The key continence mechanisms are: pressure transmission from the abdomen to the urethra, and the internal/external urethral sphincters.

Classifying urinary incontinence

The key thing here: the symptoms of incontinence do not map onto the underlying pathology/diagnosis in a one-to-one fashion, hence why some say the bladder is a “poor historian.”

Approach it by starting with the symptoms:

  • Involuntary leakage of urine when coughing, sneezing, exerting (i.e. things that increase intra-abdominal pressure) – frequency and urgency can occur with this
    • Loss of normal continence mechanisms divided into…
      • Intrinsic sphincter failure – damage during surgery; neurological dysfunction e.g. nerve damage; ageing process
      • Urethral hypermobility (urethra moves inferiorly, so pressure is no longer transmitted to close the urethra) – multiple vaginal births; low oestrogen states e.g. post-menopause; chronic cough; surgery
    • Detrusor muscle over-activity
    • Urinary tract infection (! – exclude it with a urine dip)
  • Involuntary leakage of urine due to sudden urge to urinate (urgency) – frequency and involuntary leakage during cough/sneeze/exertion can occur with this
    • Loss of normal continence mechanisms
      • Intrinsic sphincter failure
      • Urethral hypermobility
    • Detrusor muscle over-activity
    • Urinary tract infection
  • Involuntary leakage of urine that is continuous (true incontinence)
    • Fistula (vesicovaginal or ureterovaginal fistula, due to radiotherapy, cervical cancer or obstructed labour)
  • Involuntary leakage of urine with pain or haematuria
    • Red flags – suggests an underlying organic issue like a tumour, stone or trauma
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Classifying urinary incontinence. Click to expand.

Because different underlying pathologies can present in similar ways, further investigations are critical when a lady presents with involuntary leakage of urine.

Diagnosing urinary incontinence

The gold standard is urodynamics, likely with a bladder diary to understand fluid intake/output and when leakages occur.

Following urodynamics, a definitive diagnosis can be made:

  • Urodynamic stress incontinence due to loss of continence mechanisms
    • The different causes of urodynamic stress incontinence – intrinsic sphincter failure vs. urethral hypermobility – is distinguished based on history, examination and urodynamics
  • Over-active bladder due to detrusor muscle over-activity, especially during the ‘filling phase’ as the bladder fills with urine

Determining the underlying pathology is important because the treatments differ.

Treating urinary incontinence

The treatments are directed to the underlying pathology.

  • Urodynamic stress incontinence
    • General measures: pelvic floor exercise; pessaries
    • Surgical measures to correct failure of continence mechanisms:
      urethral-hypermob

      Treating urethral hypermobility with either tension-free vaginal tape (TVT) or Burch colposuspension.

      • Intrinsic sphincter failure:
        • Urethral bulking, injecting the urethral sphincter with a bulking agent to restore integrity
      • Urethral hypermobility:
        • Tension-free vaginal tape (TVT) – a mesh sling around the bladder neck,  attached to the anterior abdominal wall*
        • Transobturator tape (TOT) – a mesh sling around the bladder neck through the obturator foramina
        • Burch colposuspension – a sling created from stitches from the vagina to the pubic ligaments
  • Over-active bladder
    • General measures: bladder retraining where the interval between urination is gradually increased
    • Medical measures: anticholinergics and mirabegron to reduce detrusor muscle activity; sacral nerve stimulation
    • Surgical measures: generally a last resort – bladder augmentation to increase capacity and reduce detrusor activity; or an ileal conduit where the bladder outputs into the ileum

Some relevant health news…

TVT and TOT surgeries using mesh to treat incontinence have stopped following an inquiry due to safety concerns. If you’re interested, it was covered on Loose Women.

Pelvic organ prolapse

Pelvic organ prolapse (POP) is when one of the pelvic organs bulges into the vagina. It may present with a dragging sensation, discomfort and the prolapsed segment may be noticed.

Classifying pelvic organ prolapse

Classifying POP is easy – it’s based on (i) the vaginal wall compromised and (ii) the organ that prolapses:

  • Roof of vagina
    • Uterine prolapse (uterocele)
    • Vaginal vault prolapse
  • Anterior wall of vagina
    • Bladder prolapse (cystocele)
    • Urethral prolapse (urethrocele)
  • Posterior wall of vagina
    • Rectal prolapse (rectocele)
    • Small bowel prolapse (enterocele)

Age and race (hispanic, white) are risk factors, as well as family history, obesity and multiparity.

pop

Classifying pelvic organ prolapse. Click to expand.

Diagnosing pelvic organ prolapse

The diagnosis is clinical, based on history and Sims’ speculum examination – asking the patient to cough may make the prolapse visible.

Treating pelvic organ prolapse

Management is surgical and depends on which vaginal wall has been compromised.

IMG_0951

Surgical approaches to manage POP.

  • Roof/superior surgeries
    • Sacrohystero- or sacrocolpopexy – the uterus or vagina is fixed to the sacrum using a strip of synthetic mesh
    • Sacrospinous fixation – stitches are placed in the vagina to attach it to the sacrospinous ligament
  • Anterior surgeries
    • Burch colposuspension – the bladder neck is hitched using stitches from the vagina to the pubic ligaments
    • Anterior colporrhaphy – reinforcing the anterior vaginal wall
  • Posterior surgeries
    • Posterior colporrhaphy – reinforcing the posterior vaginal wall

Summary: urogynaecology

Phew… that is a lot. All of urogynaecology in one post, and below is the complete urogynaecology framework. There was a lot more on diagnostics/treatment than usual, primarily because this is where the most confusion lies in this topic.

urogynae

Urogynaecology medical map. ‘Loss of normal continence mechanisms’ can be divided into intrinsic sphincter failure vs. urethral hypermobility. Click to expand.

 

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