The International Continence Society (ICS) definition of cystocele, or an anterior vaginal wall prolapse, is a descent of the anterior vagina in such a way that the urethrovesical junction or any point above it is 3 cm or more above the hymenal plane.
First Steps Towards the Diagnosis
Diagnosis of a cystocele begins with a careful history of symptoms as well as the medical and occupational history. Symptoms which may relate to bladder dysfunction should be specifically asked for. These include:
- Involuntary escape of urine in moments of stress on the pelvic floor, such as hearty laughter, sneezing or coughing
- Frequency of urination
- Nocturnal awakening for the purpose of urination more than once or twice a night
- Urge incontinence
- Abnormal pattern of urination, such as frequent starts and stoppages, having to strain down, or reduced force of the urinary stream
- Symptoms of pelvic organ prolapse such as low back ache with a dragging sensation in the vagina, or a feeling of a mass coming down the vagina
Other factors to be enquired about are precipitating factors such as a history of difficult childbirth, chronic cough or lifting heavy weights routinely. This is followed by a physical examination at the doctor’s office or hospital. The examination is meant to assess the degree of severity of the cystocele, based on how much the bladder has descended into the vagina.
Physical Examination and Grading of Cystocele Severity
Proper examination requires a full understanding of the pelvic floor. Each part of the vagina must be visualized and examined at rest and under forceful straining conditions (usually called the Valsalva maneuver). This may require that the patient’s position be changed at times, from supine to standing or sitting upright, at various parts of the examination. The bladder should contain a reasonable volume of urine so that incontinence may be assessed. An accurate diagnosis is fundamental for choosing the right method of treatment.
A commonly used diagnostic classification of cystocele is that of the International Continence Society (ICS POP-Q), which uses only the degree of descent of the anterior vaginal wall. Its main drawback is that in many cases there is poor or no correlation between the patient’s symptoms (such as incontinence of urine) and the degree of cystocele observed on clinical examination. It has a moderate degree of reproducibility between different examiners. Thus in most patients, the clinical diagnosis is followed by imaging tests.
The grading is as follows:
- Grade 1 is called mild cystocele
- Grade 2 is moderate, when the bladder is at the vaginal opening
- Grade 3 is severe cystocele, and the bladder is so low that it bulges through the vaginal introitus
Tests are then performed to assess the intensity of other symptoms and look for other signs. These include imaging techniques to visualize the pelvic organs.
X-ray cystourethrography was initially used to evaluate prolapse, but has now been displaced by other imaging techniques. It is also known as a voiding cystourethrogram, and identifies the characteristic bladder descent as well as any obstruction to the flow of urine. It consists of X-ray imaging while the patient is emptying her bladder. Anesthesia is not required, but the exposure to ionizing radiation has led to a drastic reduction in the use of this test, with the availability of ultrasound imaging.
Postvoid residual volume of urine is a technique used when the patient complains of difficulty in achieving full bladder emptying. The patient may be asked to void, which is followed by the bladder imaging by ultrasound. The method employs ultrasound waves to show how much urine is left behind in the bladder. It is safe, can be repeated, and does not use ionizing radiation or require anesthesia.
In a few cases, a catheter used to be inserted to measure the remaining urine physically. If more than 100 milliliters remains, incomplete voiding is confirmed. Local anesthesia is sufficient for this test.
Ultrasound imaging is also used in order to visualize the position of the bladder and urethra, and their relationship with each other. Cystoceles are not only identified, but also graded by ultrasound, using a radiologic classification system first proposed by Green. It takes into account the degree of descent of the bladder neck, the change in retrovesical angle (which is formed by the proximal part of the urethra and the trigonal surface of the bladder) on maximal straining using the Valsalva maneuver, and also the degree of urethral rotation.
Other tests may be required if additional or contributing factors are suspected to lie behind the cystocele. The urine may be tested to rule out infections.
Certain special tests are required if the woman has symptoms such as stress incontinence, and are directed at assessing the function of the bladder and urethra. These are known as urodynamic tests or urinary function tests. They are used mostly in specialized testing as their sensitivity and specificity are yet to be fully established.
Urinary Function Tests
Electromyography is a test of a bladder muscle function using surface or needle electrodes, depending on the suspected role of muscle or nerve tissue in incontinence. The recorded patterns of the nerve impulses reveal whether the messages that are sent to the bladder and sphincters are working adequately.
Flow rate is a measurement of the volume of urine voided per unit time, and is expressed as millimeters per second. It is useful in diagnosing detrusor muscle underactivity, detrusor instability and outlet obstruction pressure. All of these may cause abnormal patterns of voiding.
Cystometrography helps to understand the pressure-volume relationship with respect to the bladder, helping to pinpoint detrusor compliance and contractility. This technique may incorporate the use of a urinary catheter with an attached cystometer that measures bladder capacity in relation to changing urine pressure.
Urethral pressure profile aims to measure and record the pressures at various points inside the urethra in order to show how a spike in pressure equalizes pressure at the bladder neck-urethral junction if the urethra is hypermobile, leading to stress incontinence. It is usually performed along with X-ray fluoroscopy in order to detect the presence of a cystocele as the reason for the incontinence.
Video cystourethrography or videourodynamics combines voiding cystourethrography with cystometrography, thus providing a simultaneous record of pressure and structural-functional measures within the bladder. It includes bladder capacity, bladder wall compliance, detrusor pressure and urethral closure pressure, voiding flow rate and voided volume. It is usually reserved for tertiary centers, and for failed continence surgery, but also when other tests do not provide satisfactory results.
Reviewed by: Dr Tomislav Meštrović, MD, PhD