2. URETHRAL STRICTURES
Definition
-Fibrosis of the urethral urothelium leading to scar tissue
formation which contracts and reduces the caliber of the
urethral lumen, causing resistance to the antegrade flow of
urine.
-Relevant Anatomy:
The urethra is divided into anterior and posterior segments.
The anterior urethra (from distal to proximal) includes the
meatus, fossa navicularis, penile or pendulous urethra, and
bulbar urethra. It lies within the corpus spongiosum, beginning
at the level of the bulbous urethra and extending distally
through the length of the penile urethra.
-The bulbar urethra begins at the root of the penis and ends at
the urogenital diaphragm.
-The penile urethra has a more central position within the
corpus spongiosum in contrast to the bulbous urethra, which is
more dorsally positioned
The posterior urethra (from distal to proximal) includes the
membranous urethra and the prostatic urethra.
-The membranous urethra involves the segment extending
from the urogenital diaphragm to the verumontanum.
- The prostatic urethra extends proximally from the
verumontanum to the bladder neck.
The soft tissue layers of the penis, from external to internal
Skin
Superficial (dartos) fascia
Deep (Buck) fascia,
Tunica albuginea surrounding the corpora cavernosa
and corpus spongiosum.
-The superficial vascular supply to the penis comes from the
external pudendal vessels, which arise from the femoral
vessels.
-The deep penile structures receive their arterial supply from
the common penile artery, which arises from the internal
pudendal artery.
-The scrotum receives its vascular supply via branches from
both the external and internal pudendal arteries
Etiology:
Congenital or acquired.
Congenital
1.Epispadias-Abnormal urethral opening on the dorsal aspect
of the penis.
Some epispadias are accompanied by anterior abdominal wall
defects and bladder extrophy
2.Hypospadias-abnormal urethral opening on the ventral
aspect
3.Urethral valves especially the posterior urethral valves
4.Congenital stenosis of the meatus urethra
Acquired
The most common causes of urethral stricture
1.Traumatic (commonest cause) e.g. pelvic fracture (of the
pubis & ischial rami), saddle injury, penile fracture
2. Iatrogenic.-surgery (Prostatectomy) and instrumentation
(Indwelling catheter,Urethral endoscopy)
3.Infectious- Post-gonorrhoea, tuberculous urethritis,
The various parts of the male urethra have relatively different
acquired etiology of the urethral stricture
Anterior urethra.
i)Bulbar urethra
Trauma-falling astride(man-hole
injuries),instrumentation-passing sounds ,infections especially
around the glands around this segment makes treatment
difficult
ii)Penile urethra –instrumentation, infections
iii) Glans meatus-instrumentation, infections especially the
BXO(the balanitis xerotica obliterans). It is thought to be
caused by lichens causing inflammation and leukoplakia.It is
usually very painful.
Posterior urethra
i)Bladder neck-Instrumentation, cystitis, TURP
ii)Prostatic urethra/membranous urethra-Trauma-Fracture
pelvic rami ,surgery-open or closed prostatectomy
,instrumentation
DIAGNOSIS
Diagnosis is made based on a suggestive history, findings on
physical examination, and radiographic or endoscopic
techniques.
Clinical presentation.
The most common presentation includes obstructive voiding
symptoms
The patient may present with acute urinary retention-acute
onset, painful and patient can’t pass urine.
Chronic urinary retention-gradual occurrence, not painful and
patient can pass some urine.
1. Straining at urination
2.Weak stream, splaying of the urinary stream
3 Urinary retention/ incomplete emptying of the bladder
4. Urinary terminal dribbling,
5. Urinary intermittency/hesitancy
6. Dysuria
7. Nocturia
8. Recurrent Urinary tract infections
These symptoms are progressive for many patients.
Stricture Complications
1.Recurent Infection e.g. UTI, STI
2.Calculi formation
3.Urine Extravasation
4.Urethral diverticulum
5.Periurethral abscess
6. Urethral fistula - Usually 2° to bursting or incision of a
periurethral abscess. If the fistulae arise behind a tight
stricture, there may be multiple openings - watering-can
perineum
7.Abdominal straining to void urine causes; Hernia
,Haemorrhoids, Rectal prolapse
8.Dilated uropathy- hydroureters, hydronephrosis
3. chlamydial infection of the membranous urethra or
schistosomiasis
4. Malignancy-penile shaft squamous cell cancer, field effect
from transitional bladder cancer.
The male urethra is about 15-17cm
The female urethra is 3.5-5.5 cm
Investigations
Lab Tests
1. FHG-for theatre
2. Urinalysis-UTI
3. Random blood sugar-DM neurogenic bladder can
present in similar fashion
4. U/E/C-theatre prep and hydronephrosis.
5. Elderly patients PSA –prostatic cancer or
enlargement
Imaging Studies:
The entire urethra, both proximal and distal to the strictured
area, must be evaluated endoscopically and/or radiographically
prior to any surgical intervention.
Radiographic evaluation of the urethra with contrast studies is
best achieved by retrograde urethrogram or antegrade
cystourethrogram if the patient has an existing suprapubic
catheter
Accurately documenting the extent and location of the stricture
is important so that the most effective treatment options can be
offered to the patient
Complete stricture - MCU + Ascending /Retrograde CU
Incomplete stricture - MCU
1-Retrograde urethrogram
involve placing a nonlubricated 8F or 10F urethral catheter into
the fossa navicularis and inflating the balloon with 1-3 mL of
sterile water until the balloon occludes the urethral lumen.
Approximately 10 mL of iodinated contrast media then is
injected into the catheter under fluoroscopy, and images of the
anterior urethra are taken.
This must be combined with MCU to localize the stricture
2-An antegrade cystourethrogram
involves distending the bladder with water-soluble contrast
media via a suprapubic tube or urethral catheter.
A scout film is taken before administration of contrast material.
Once the bladder is fully distended with contrast media, the
suprapubic tube is clamped or the urethral catheter is removed
and the patient is asked to void. Spot films are taken before,
during, and after the voiding phase.
3.Micturating cystoureathrogram
This is usually sufficient is posterior urethral valves in children.
4. Cystourethroscopy
Endoscopic evaluation can be conducted by flexible
cystourethroscopy -/+ biopsy
5.Abdominal pelvic ultrasound
Evaluate the bladder wall for fibrosis and hypertrophy.
Ureters and kidneys evaluated for dilated uropathy
6.IVU
This is indicated if hydronephrosis and hydroureters.
Permanent urethral stents
Permanent urethral stents are endoscopically placed. Stents
are designed to be incorporated into the wall of the urethra and
provide a patent lumen. They are most successful in
short-length strictures in the bulbous urethra. Complications
occur when a stent is placed distal to the bulbous urethra,
causing the patient pain while sitting or during intercourse.
Other complications involve migration of the stent.
-It may be best reserved for patients who are medically unfit to
undergo lengthy open urethral reconstruction procedures
Internal urethrotomy
Internal urethrotomy involves incising the stricture transurethral
using endoscopic equipment. The incision allows release of
scar tissue. Success depends on the epithelialization process
finishing before wound contraction significantly reduces the
urethral lumen caliber.
i)Direst vision internal urethrotomy (DVIU)
Endoscopic incision is made under direct vision at the 12
o'clock position with a urethrotome. Care must be taken not to
injure the corpora cavernosa because this could lead to
erectile dysfunction.
It is not done for membranous urethra because of the proximity
to the internal sphincter mechanism.
DVU is not appropriate for bulbar urethra and open
urethrotomy advocated
ii) Internal Blind urethrotomy
iii) Perineal urethrotomy
Postoperative details
1. Patients are placed on bedrest for 24-48 hours, depending
on the extent of the procedure.
2 .Intravenous antibiotics are continued for 24 hours and then
followed with oral culture-specific antibiotics or antibiotics with
good gram-negative coverage for 2-3 days.
3. Advive on sexual abstinence
4. Catheter left in situ for 2 weeks
5. Wounds should be washed with soap and water daily after
drains are removed.
Prior to removal of the urethral catheter, a voiding
cystourethrogram is conducted with contrast, instilled through
the suprapubic tube. If no evidence of contrast extravasation
occurs and the suture line is intact, then the urethral catheter is
removed and the suprapubic tube is capped.
Complications
1.Urinary tract infection
2.Wound infection
3.Wound dehiscence
4.Urethrocutaneous fistula
5.Recurrence of urethral stricture
Post-op
-Catheterize with a 3-way catheter for irrigation for 1-2days
(Until clear on irrigation)
-Insert urethral catheter for 2wks
4. MANAGEMENT
Dilatation
-The goal is to stretch and dilate the stricture without
producing additional scarring and allow for urine flow
-Serial dilatations first 2 weekly ,then monthly,2 monthly ,6
monthly and aim for dilatation annually.
-It may be curative in patients with isolated epithelial strictures
(no involvement of corpus spongiosum). -However, the trend
has been towards endoscopic and open surgical management
of the strictures.
Complications of DVU
a) Recurrence of stricture - is the most common
complication –very high up to 50 %of case
b) Bleeding.
c) Extravasation of irrigation fluid into perispongial
tissues.
d) Increasing fibrotic response worsening the stricture.
Typically, an indwelling urethral catheter is left in place for 14
days to allow granulation tissue re-epithelization
Open reconstruction
Primary repair –One stage open urethroplasty
Primary repair involves complete excision of the fibrotic
urethral segment with re-anastomosis. The key technical points
that must be followed include
Complete excision of the area of fibrosis
Tension-free anastomosis
Widely patent anastomosis.
Primary urethrotomy depend on site and length of the stricture.
Primary repair typically is used for stricture lengths of less than
2 cm. Complete strictures resection and free tube graft or
pedicle graft can be done
In pedicle graft the scrotal or penile skin may be rotated and
used as a tissue graft although it has many disadvantages and
less popular. The scrotal skin has ruggae, hair and sebaceous
gland. Leads to collection of urine and stasis and infection.
Commonly used is buccal mucosa. Advantages include: 1.The
tissue is resistant to infection and trauma.
2. The epithelium is thick, making it easy to handle.
3. The lamina propria is thin and highly vascular, allowing
efficient imbibition and inosculation.
4. Harvesting is easier than other free grafts or pedicled flaps
5. Elastic and can be stretched.
NB. In penile strictures no primary anastomosis done because
of risk of chordee formation. Do grafting or staged urethral
repair.
The repair is left stented with a small silicone catheter in the
urethra for 2weeks.
Staged urethroplasty
Two-stage urethroplasty
If previous procedures are unsuccessful
Stricture >2cm
Penile strictures-avoid chordee formation
Multiple strictures
1st stage
-Open up the urethra and excise stricture and surrounding
-Repeat Urethral calibration/Flow rate to determine
improvement
-Discharge on clean intermittent self catheterization with
Nélaton catheter (Filiform is better)
5. fibrotic tissues
-Suture it to the surrounding skin & leave urethral catheter
in-situ for 2wks as the wound heals.
-After 2 weeks remove the catheter and start serial dilatation
every 2 weeks of the proximal stoma for 8 weeks.
During this time the urine may be passed from the proximal
stoma created in the urethra.
2nd stage
Refashioning of the urethra & perineum by covering of the
urethra with skin flaps from both sides.
