(1)
Department of Urology, University College Hospital, London, UK
(2)
Institute of Urology, London, UK
Urethral strictures are relatively commonly encountered in urological practice. It is essential that all trainees are aware of how to deal with a stricture when encountered to ensure that a patient has the best outcome.
Aetiology of Urethral Strictures
Presentation
A patient will usually present with urinary symptoms of voiding dysfunction with hesitancy, a poor stream and straining. A primary urinary tract infection may be the presenting feature of a urethral stricture. Straining is not usually a symptom associated with prostatic outflow obstruction but more commonly with a stricture or a poorly contractile bladder. A patient may present in retention of urine but this is less common. If a patient has symptoms of bladder outflow obstruction then much depends upon the patient’s age and the background history as to whether or not there has been instrumentation. In a younger patient if he presents with voiding difficulty then a stricture should be at the top of the list of differential diagnoses. This affects how the investigation of voiding dysfunction is performed.
Having taken a history the patient should be examined for a palpable bladder and a prostate examination to assess prostate size and consistency.
Investigation
A primary free flow rate and scan should be performed in all cases. A urine culture should be obtained.
The classical stricture flow rate usually has a square pattern. If this is encountered in any patient then a stricture should be at the top of the list of differential diagnoses.
Urethrogram Versus a Cystoscopy
The question is what is the most appropriate way to diagnose a stricture? Is it by a flexible cystoscopy under local anesthesia or by ascending urethrography?
The author’s opinion is that it is more logical to perform an ascending urethrogram to confirm the stricture, its position and length than to perform a flexible cystoscopy. Although a stricture will be seen at a flexible cystoscopy one does not know how long, how tight and where the stricture is. After diagnosis the patient would need to come back for further investigation and likely endoscopic treatment. A urethrogram can more easily generate a diagnosis and provide a means of discussing appropriate treatment.
The most effective long-term treatment of strictures is an urethroplasty but as up to 65% of strictures will be resolved by endoscopic measures it is certainly worth treating any stricture with an endoscopic procedure.
Endoscopic Surgery of Strictures
In order to manage a stricture very much depends upon its site, its length, the age of the patient, the aetiology and whether or not there may be associated bladder outflow obstruction caused by prostatic enlargement.
It is important that any patient even if elderly, who has prostatic obstruction but also has a stricture that the stricture should be treated first and separate from any prostatic obstruction. The stricture may be the primary cause of the voiding dysfunction and not prostatic enlargement.
What Should Be Used to Perform a Cystoscopy and Treatment of a Stricture?
The ideal instrument is an optical urethrotome , the Sachse instrument . This has a small blade with a trigger mechanism, which allows the stricture to be cut. It also has a guide channel to allow placement of a guide wire.
For the experienced surgeon it may not always be necessary to pass a guide wire but for the less experienced surgeon passing a guide wire through the stricture will very much aid the division of a stricture with the urethrotome.
Should the Urethra Be Cut at 6 or 12 o’Clock?
This very much depends upon whether or not it is suspected that urethroplasty is to be likely.
If an urethroplasty is to be performed this usually involves placing a graft at the 12 o’clock position. It is thus logical to divide the urethra at the 12 o’clock position. Thus if scarring does occur this can be excised at the time of a future urethroplasty if necessary.
Gently teasing the urethra open with the urethrotome with a guide wire to provide a vision of the continuity of the urethra is the most effective way of dealing with a stricture below the membranous urethra. If the grooved catheter guide is placed on the optical urethrotome at the outset then once the stricture has been divided and the endoscope has reached the bladder a catheter can be placed within the guide into the bladder without any difficulty. Plenty of lubrication should be used to ensure that the catheter slides easily into the bladder. The grooved guide will accommodate a 16 French silicone catheter .
Strictures of the urethra can be blindly dilated but this very much depends upon the experience of the surgeon. A blind urethral dilatation using Cluttons sounds is not recommended for an inexperienced surgeon. There is the danger of causing a urethral injury and a false passage. If a stricture is short or relatively rigid and cannot easily be negotiated then blind dilatation can be undertaken but only with experience.
