Causes
Urethral stricture results from an injury to the urethra, either from trauma (accident or instrument injury) or from severe inflammation arising from an infection.
Causes of urethral injury include:
- A straddle injury, including falling on a bicycle bar or getting hit in the area close to the scrotum.
- pelvic fractures
- catheter insertion, especially from injury during intermittent self-catheterization
- radiation
- surgery performed on the prostate
Rare causes include:
- a tumor located in close proximity to the urethra
- untreated or repetitive urinary tract infections
- sexually transmitted infections (STIs) like gonorrhea or chlamydia
Symptoms
Symptoms of patients suffering from urethral stricture is the a result of narrowing of the urethra, and include
- weak urine flow
- sudden, frequent urges to urinate
- a feeling of incomplete bladder emptying after urination
- frequent starting and stopping urinary stream
- pain or burning during urination, which may indicate infection
- inability to control urination, leaking of urine (incontinence)
- pain in the pelvic or lower abdominal area as a result of an over-distended full bladder
- urethral discharge
- inability to urinate (this is an emergency and needs intervention to release the urine
Diagnosis
The suspicion of a case of urethral stricture may be based on a full history of symptoms as above
Uroflowmetry will show poor flow of urine, recorded in the uroflowmeter machine (see the subsection on urodynamics)
You will be made to pass urine in privacy into a uroflowmetry machine and the flow rate and pattern is recorded.
The uroflow patterns can be noted by a continuous tracing which is recorded when the urine flows along the uroflowmetry machine. The urologist can determine the provisional diagnosis after the uroflowmetry.
Uroflowmeter to assess urine flow
Uroflowmetry tracing to assess urine flow
Urethrogram may be necessary to evaluate the extent of the urethral stricture. It consists of instilling a dye into the urethra and taking a few X-rays. The dye in the urethra will outline the urethral caliber and detect any narrowing which indicates a urethral stricture.
Urethral strictures seen clearly after urethrograms
A cystoscopy procedure where a small tube with camera is inserted into the urethra up to the bladder
Cystoscopy may be done by inserting a small tube with a camera into the urethra to view the inside of the bladder and urethra, and hence to check for any stricture. The procedure is reasonably painless, may be associated with mild discomfort.
Treatment of urethral stricture
It is important to note that the treatment of urethral strictures do not necessarily follow a step-ladder pattern or flow chart from minimally invasive procedure to a more major procedure.
There are no drugs or medications to treat urethral stricture.
Failure to treat urethral strictures early and promptly will result in an over-distended bladder with urinary retention, back pressure of the kidneys with kidney swelling (hydronephrosis) and finally resulting in kidney failure.
Intermittent self-catheterization for urethral stricture, although used several decades ago, is not advisable currently because it is very uncomfortable, it does not cure the urethral stricture disease, the person will be subjected to this intermittent self-catheterization for the rest of his life, and it can cause false passages and injuries resulting in making the stricture longer and worse for definitive curative treatment later.
The only indication for intermittent self-catheterization for urethral stricture disease in the current modern era is only reserved as a palliative procedure (relieving the urine flow temporarily without actually curing the disease) and when a person is unfit for definitive surgery.
The best type of treatment for urethral strictures should be based on a very detailed assessment of the urethral stricture, the exact site of the urethral stricture, the length of the stricture, the density or toughness of the stricture and the possible cause of the stricture, whether it is due to a pelvic fracture with a distraction of the ends of the urethra or just an infection causing a short stricture. This is because urethral stricture occurs due to scar tissues causing the urethral narrowing. Once this occurs, a minimally invasive technique may nor address this scar tissue, unless the scar tissue is very soft and short. Hence for longer and denser strictures, the best treatment would be urethroplasty, where the scar tissue will be excised (removed) completely for the best chance of cure.
The different treatment modalities of urethral stricture disease would depend on the proper assessment of the type of stricture and include:
- Minimally invasive techniques – dilatation of the stricture and optical urethrotomy
- Urethroplasty
- Urinary Diversion
Minimally invasive technique
It may be done either as dilatation of the stricture or cutting the stricture (known as optical urethrotomy).
This in general is only used for short strictures less than 1.0-1.5 cm, and in the bulbar urethra (the beginning part of the urethra just after the prostate, and at times in the penile urethra.
If the stricture is much longer than this, the strictures may continue to recur, and urethroplasty is the best option for cure.
Urethral dilators used for stricture dilatation
Urethroplasty
This is the definitive surgery for urethral stricture which gives the best cure rates.
- This is indicated for longer strictures more than 1.5 cm, or in strictures where there is a long defect in the urethra, a tough and dense stricture, or in a failed dilatation or optical urethrotomy after a first try.
- Urethroplasty consists of cutting the stricture with all scarred tissues, and stitching back the urethra, known as anastomotic urethroplasty.
- There are times when a graft substitution will be required for longer strictures, known as substitution urethroplasty.
- There are other times when substitution urethroplasty may require a staged procedure, i.e. the procedure done in more than one stage.
- The cure rates for urethroplasty is good, about 90-95% for anastomotic urethroplasty, and 70-85% for substitution urethroplasty depending on the graft uptake.
Anastomotic urethroplasty. Pic taken from Translational Andrology and Urology;
http://tau.amegroups.com/article/view/17038/18025
Substitution urethroplasty. Pic taken from Translational Andrology and Urology;
http://tau.amegroups.com/article/view/17038/18025
Urinary diversion
This may rarely be necessary for extremely severe strictures with extensive damage or with cancer. This consists of permanently rerouting the flow of urine to an opening in the abdomen, known as an ileal conduit. It involves using part of the intestines to help connect the ureters to the opening. Urinary diversion is usually only performed if the bladder is severely damaged or if it needs to be removed.
