Suprapubic catheters

Urethral and Suprapubic catheters (SPCs) come with similar issues.

SPCs are surgically placed catheters which enable the drainage of urine from the bladder and bypass the urethra.

Indications:

1. Urinary retention following urethral trauma - short-term in acute retention and long-term in high-pressure retention

2. Patients indefinitely requiring a long-term catheter, mainly in neurological conditions such as MS/stroke/demyelinating conditions

3. Patient and carer preference for continence care

4. Maintaining sexual function

5. Inserted during a bladder repair

6. Less frequent blockages
   
   

Insertion:

1. Traditionally, a ‘blind technique’ of SPC insertion was employed where a full and palpable bladder was assumed to displace the bowel away from the site of puncture.
   Luckily, we don’t rely on this tradition in the era of imaging!

2. Ultrasound or CT guided SPC insertion - the method of choice as it reduces the risk of bowel injury.

The landmark for SPC insertion is 2 finger breadths above the pubic symphysis.

As a general rule, once the first catheter is placed, it should not be changed unless done so by a urologist or a Urology CNS within the first 6 weeks. This allows the catheter tract to form, and early removal risks a loss of the tract, requiring salvage in a hospital or clinic. A SPC tract takes approximately 4 weeks to form.

Patients may present with the following problems:

1. Blocked catheter

2. Expelled catheter

3. Blood in the catheter

4. Difficulty re-catheterising

5. Pain and bypassing

6. Formation of bladder stones secondary to the SPC, which acts as a foreign body

Management of SPC problems:

1. Blocked catheter - Flush gently with 10-20 ml. This will usually dislodge the debris and allow the catheter to drain. If the catheter has been in for a while and is due for a change, then replacement of the catheter with an aseptic non-touch technique will resolve the problem.

2. Expelled catheter - Usually noted when a patient with a weak abdominal wall has a bout of coughing or severe bladder spasms, displacing the balloon and catheter. Needs to be replaced ASAP.

3. Blood in the catheter - Assess for symptoms of a UTI. A urine dip from the catheter is a poor measure of infection, as it will almost always be leukocyte and nitrite heavy, with white cells detected. If the patient does not have features of an infection, it is worth referring the patient to a haematuria clinic for full assessment. Bladder stones can also cause haematuria, and a bladder or upper tract cancer must be considered (see our section on visible haematuria for more details.)

4. Difficulty re-catheterising may be due to poor technique/ lack of confidence in performing a catheter exchange or because the tract has stenosed or has been lost. In this case, a guidewire may be a useful adjunct (if used correctly) to find the tract and railroad a catheter over. If you have any difficulty, it is best to speak to the urology registrar for advice.

5. Pain and by-passing is often due to bladder spasms - a simple anticholinergic will relieve this, and mirabegron may be used at the lowest possible dose.
   Note that bypassing from the urethra can occur, and as long as good volumes of urine are passing via the SPC, the patient can be reassured. This is likely due to low resistance at the urethra. If high volumes of urine are passed per urethra, consider a blocked SPC and manage as described above.
   Persistent bypassing can be assessed in the outpatient setting with appropriate cystometry.

6. Bladder stones - a catheter forms a nidus for stone formation. A stone can cause haematuria and spontaneous expulsions of the catheter due to ruptures of the balloon caused by the stone.

SPC exchanges:

This is a generic skill that any doctor should be able to perform. Unlike the 20 + cm of male urethra a catheter would need to pass through, an SPC tract is merely 4-5 inches from the skin surface, which is much more straightforward.

1. Consent from the patient.

2. Prepare your equipment: A sterile catheter pack, an appropriate size of catheter which should be the same size and length as the existing catheter (the catheter size is usually noted at the end of the catheter as it joins a bag and patients often have a catheter passport), a 10ml syringe, a drainage bag and a cleaning preparation.

3. It is useful to fill the bladder with about 50ml of saline before exchanging the catheter to help confirm that the new catheter is sited correctly.

4. Take note of the external length of the existing SPC. This serves as a useful guide as to how long the new catheter must be advanced into the bladder.

5. Deflate the catheter balloon and gently remove the catheter. It is not unusual for sediment and the deflated balloon “lip” to catch fascia and tissue on the way out. Therefore, a rotational movement on withdrawal of the SPC will help.

6. Quickly prepare the area with cleaning solution, lubricate the end of the new catheter and gently but with firm pressure, insert the new SPC through the tract. Maintain an angle of 90 degrees on insertion.

7. Once urine is draining from the catheter, inflate the balloon with 10ml of sterile water and connect to a drainage bag.

Video 1 - SPC exchange

Images and videos:
Thumbnail - Used under the Creative Commons license - James Heilman, MD, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons
Video 1 courtesy - Swansea Bay NHS TV - https://www.youtube.com/watch?v=lRCtvr79trU