Author: Associate Prof Siow Woei Yun, Raffles Hospital

Urinary incontinence refers to the involuntary leak of urine. It affects approximately 30-40% of women worldwide. The commonest causes of urine leak include stress urinary incontinence, urge urinary incontinence and mixed urinary incontinence.

At present, the help seeking rate for women with urinary incontinence is less than 50%. This is attributed to many common misconceptions. These misconceptions include:

  • Acceptance as part of ageing;
  • Belief that symptoms are mild/selflimited;
  • Embarrassment;
  • Ignorance regarding sources of help;
  • Low expectations for treatment and
  • Fear of invasive procedures.

However, urinary incontinence is not merely a medical problem. It is also a social problem because people close to the affected individual may not comment on the urine leakage but they will certainly smell the evidence. Thus, urinary incontinence is a problem that must be addressed and solved.

Stress urinary incontinence refers to urine loss upon straining e.g. cough, sneeze, laugh, carrying heavy loads, skipping, jumping, brisk walking, and sometimes even standing. This occurs when the pelvic floor is too weak to keep the urethra closed under situations of stress/exertion thus resulting in urinary incontinence. Risk factors for this problem include pregnancy, childbirth, ageing, menopause, manual labour, obesity and repetitive strain e.g. chronic cough, chronic constipation and high impact sports.

Non-surgical treatment e.g. pelvic floor exercise, may improve the symptoms by 30-60%, but cure is rare. Surgery is the main curative option for stress urinary incontinence with 85-95% cure rate. Surgical approach and results have improved over the past half century. In the past, surgery required a long incision similar to that for a Caesarean section i.e. Burch colposuspension. This evolved to become three smaller incisions, one in the vagina and two over the lower abdomen i.e. tension-free vagina tape (TVT tape) insertion. Today, we are able to achieve equivalent results with a single vagina incision and no skin incisions i.e. scarless transvaginal surgery for Miniarc tape insertion. With this improved surgical method, surgical complications e.g. bleeding, bladder injury, bowel injury, urinary retention, overactive bladder are reduced or even removed. The length of tape that is inserted is halved with the new Miniarc tape. This reduces the risk of non-healing, infection and tape erosions. Most cases of Miniarc tape insertion can even be performed as a day case, with no need for hospitalisation.

The author’s experience with the Miniarc surgery has been highly satisfactory. The success rate is close to 100%. Patients who are undergoing surgery for the first time achieve particularly good from the first week after the surgery. Patients who have undergone previous surgery before the Miniarc operation can achieve equivalent results, but they take a longer recovery period to achieve the final continence state.

Urinary incontinence may also result from urge urinary incontinence. Patients usually complain of urinary frequency i.e. more than eight times in 24 hours, urgency i.e. strong urge to pass urine that is difficult to suppress, nocturia i.e. waking up many times from sleep to pass urine, and sometimes, urinary incontinence. The combination of these factors is known as the overactive bladder syndrome.

Overactive bladder may be caused by abnormal bladder function or may result from urinary tract infection, urinary stone disease or even urinary tract cancer. Thus a detailed evaluation of the urinary system is needed to determine the exact cause of overactive bladder syndrome to ensure that the appropriate treatment is instituted.

Medication is the mainstay of treatment for overactive bladder arising from abnormal bladder function. Over the years, medication has increased in sophistication. Today, oral medications are available in once-daily dosing and have better efficacy – side effect ratio compared to older medications. Approximately six different medications are available in Singapore. These include Vesicare (Solifenacin), Detrusitol (Tolterodine), Mictonorm (Propiverine), Spasmolyt (Trospium Chloride), Flavoxate and Ditropan (Oxybutynin). Patients have different severity of disease and respond differently to the same medication, thus treatment must be tailored to the individual. For patients who do not respond to medication, further investigations are performed to evaluate the bladder function and selected patients may receive Botulinum toxin A injection into the bladder wall to control the condition.

The additional tests may include a urodynamics study. This is a specialised test to study the dual functions of the urinary bladder i.e. filling and voiding.

A fine catheter is inserted into the bladder to allow for bladder filling and to measure pressures generated by the bladder. During the process of bladder filling, the ability to sense progressive filling is assessed. Bladder stability and capacity and the presence of urinary leaks are also assessed. During the process of voiding, the pressures generated by the bladder are measured and the completeness of bladder emptying is assessed.

Suitable patients who undergo Botulinum toxin A injection will have the medication injected into their bladder walls via the cystoscope. There is no need for skin incisions. The effect of the injection lasts for six to nine months. The rate of symptom recurrence varies for different patients. When the recurrent symptoms are bothersome, a repeat injection can be administered.

Patients with both stress urinary incontinence and overactive bladder have mixed urinary incontinence. Management of mixed urinary incontinence is more complex than either condition alone. Patients need detailed urological investigations before starting/receiving individual-specific therapies for both conditions so as to achieve the best outcome for the patient.

Urinary incontinence is a common symptom and sign, but the causes are varied and a detailed evaluation is necessary to determine the cause in the individual patient. An accurate diagnosis allows for more precise and effective therapy.