Urethral dilation

Types of dilators:

1. Cluttons dilators - curved tip metal dilators

2. Hegar's dilators - straight metal dilators

3. S-shaped dilators - semirigid disposable dilators

Image 1 - Cluttons, Hegars and S-shaped dilators. Note that the Cluttons and Hegars dilatators are solid metal and do not have a perforation to thread a wire through. The S-shaped dilators, on the other hand, are perforated at the tip and end.

Indications:

Dilating a urethral stricture
Dilating a stenosed urethral meatus / submeatal stenosis

The procedure is generally well tolerated with a lubricating anaesthetic jelly.

General rules:

1. Start with the smallest size.

2. If resistance is encountered - DO NOT PUSH.

3. Pass a guide wire under vision before S-shaped dilatation.

4. Do not dilate beyond the required length of the stricture - when adequately dilated - revisit with a cystoscopy and assess for further/proximal strictures.
   

Risks:

1. Infection

2. Bleeding

3. Trauma to the urethra and creation of false passages

4. Pain post procedure

Procedure:

The procedure below is specific to ‘S’ shaped dilators.

1. Insert a flexible cystoscopy and identify the position of the stricture as well as the diameter of the urethra.

2. Thread a guidewire through the working channel and advance it so it reaches the bladder.

3. Remove the flexible cystoscope, leaving the guidewire in place.

4. Prepare the S-shaped dilators by pouring distilled water over them whilst in the package (the dilators have a hydrophilic coating.)

5. Threat the smallest dilator over the guidewire and insert it with the tip pointing upwards.

6. Push the dilator inwards until urine starts to come out of the end of the dilator. This confirms that it is in the bladder. Bleeding indicates that there is urethral trauma. IF in doubt - stop, insert a flexible cystoscope and re-assess the stricture and confirm the correct location of the guidewire.

7. The dilator does not need to be in for more than 10-15 seconds.

8. Keep moving up in terms of size, gradually working your way up to a reasonable size to allow an easy insertion of a catheter.

9. Once the final dilator has been removed, thread a catheter over the guidewire until it is within the bladder and urine begins to drain.

Cluttons dilators have a curve at the end. When inserting a cluttons dilator or any similar angulated dilator, insert the same with the ‘L’ directed inferiorly. Once within the urethra, you may rotate the dilator 180 degrees and insert it to dilate the stricture.

Hegar’s dilators are straighter dilators, and insertion is much more straightforward.

Resistance at the urethral stricture is expected. However, if you feel that you are out of your depth, ask for help, or you just might induce urethral trauma and a possible subsequent stricture.

Some clinics may have shorter, flexible single packaged urethral dilators (in packaging similar to a hypodermic needle). These are useful in females and in a stenosed urethral meatus.

Images:
Thumbnail - http://de.smiki.org/Bild:Dilatatoren-Hegar.jpg Used under the Creative Commons licence.
Image 1 - Comparison of commonly used dilators. Copyrights Uromate.