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284 Challenging Concepts in Urological Surgery
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The UK Department of Health estimates that >16,000 males with urethral strictures
are seen in the National Health Service annually and >75% of them required operative management, at a cost of approximately £10 million annually.
reported prevalence of urethral strictures across age groups is 10 per 100,000 in young
men and up to 100 per 100,000 in those >65 years.
Learning point Anatomical considerations
The urethra is 15– 25 cm long, anatomically divided into anterior and posterior urethra. The anterior
urethra consists of the meatus, navicular fossa, penile (or pendulous) urethra, and the bulbar urethra
(extends from the penoscrotal junction to inferior perineal fascia). The penile urethra runs ventrally
within the corpus spongiosum, which is a mass of spongy tissue, expanded posteriorly to form the
urethral bulb which lies opposed to the urogenital diaphragm. The urethra enters the bulb near
its superior aspect. Spongiosal tissue distal to the bulb sits in a groove on the under- surface of the
conjoined corpora cavernosa and tapers along its length until it expands to form the glans penis
distally. Figure 29.3 demonstrates this and the relative position of the urethra within the spongiosum in
cross section.
The posterior urethra consists of the membranous urethra, prostatic urethra, and bladder neck.
The membranous urethra contains the distal urethral sphincter in its wall and is surrounded by
1,2
In the UK, the
3
Figure 29.3 Illustration of the urethra and its relations within the corpus spongiosum.
the periurethral part of the pelvic diaphragm as it passes through it. The bladder neck consists of a
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prominent sphincter in males. Each section of urethra is lined by a different variation of epithelial
cells: fossa navicularis by squamous epithelium, penile and bulbar urethra by pseudostratified
columnar epithelium, and the membranous and prostatic urethra by transitional epithelium.
The Scarpa’s fascia of the lower abdominal wall continues down into the perineum where it is termed
Colles’ fascia. It extends on to the penile shaft where it is called the penile fascia or Gallaudet’s fascia.
The blood supply to the urethra is segmental which means that it is possible to mobilize the urethra
without ischaemic problems along its whole length, provided that the proximal and distal blood
supply is intact. The inferior vesical, middle rectal, and pudendal arteries, arising from the anterior
division of the internal iliac artery, provide the urethral blood supply. The internal pudendal artery
gives three main branches: (1) the bulbourethral artery, which supplies the bulb of the penis, the
membranous and penile urethra; (2) the dorsal artery, which runs dorsal to the corpora cavernosa
within the Buck’s fascia; and (3) paired cavernosal arteries, within the corpus cavernosum, which run
along the length of the shaft.
4
285Case 29 Urethral stricture disease
Aetiology
Learning point Aetiology of urethral strictures
Strictures of the anterior urethra are broadly caused by lichen sclerosis in 30%, instrumentation
(including catheterization, cystoscopy, hypospadias repair) in 30%, and are idiopathic in 30%. About
10% of urethral strictures are caused by direct trauma (fall astride injuries), where there is very limited
spongiofibrosis and an anastomotic repair is usually successful in these cases. Conversely, ischaemia
is the common underlying pathology in urethral strictures, but is rarely referred to as such.5 The
aetiology of strictures varies slightly between the bulbar and penile urethra as shown in Table 29.1.
Posterior urethral stenoses, on the other hand, are usually caused by severe trauma and are often
associated with pelvic fractures and involve a distraction injury or avulsion of the membranous urethra
and are otherwise known as pelvic fracture urethral injury.7 Much less common, but increasing in
incidence, certain treatments for prostate cancer (high- intensity focused ultrasound, radiotherapy,
brachytherapy; radical retropubic prostatectomy) can lead to prostatic urethral strictures and
distraction injuries and fistulae. A complicating feature of these cases is the damage to blood supply
resulting from radiotherapy.
Table 29.1 Aetiology of urethral strictures by site
Idiopathic Iatrogenic Inflammatory Trauma
Penile 15% 40% 40% 5%
Bulbar 40% 35% 10% 15%
6
Pathophysiology
Strictures occur as a result of a process termed ischaemic spongiofibrosis. Focal extravasation of urine occurs as a result of an insult (infective, inflammatory, iatrogenic)
leading to subepithelial fibrosis within the corpus spongiosum, and as consequence
the vascular supply is lost and fibrotic plaques form. If the fibrotic foci coalesce circumferentially around the urethra, then a stricture may form.
8
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Clinical features
Seventy per cent of patients present with voiding lower urinary tract symptoms
(hesitancy, poor flow, terminal dribbling or a feeling of incomplete voiding).9 Acute
presentations include acute urinary retention, recurrent urinary tract infections,
epididymo- orchitis, or periurethral abscesses
10
Investigations
Clinical tip Considerations
when planning treatment
A patient with poor dexterity may
not be a suitable candidate for
DVIU and ISD; equally, a patient
with multiple comorbidities may
not be an appropriate candidate
for major reconstructive surgery.
Expert comment Endoscopic
treatment
In the case of a young and fit
individual, often even if much
older, treatment with curative
intent is appropriate. The location
and length of the stricture will
determine the optimal form of
treatment. Endoscopic treatment
has most success in short bulbar
stricture and least success in
long penile strictures. There is no
evidence to suggest DVIU is more
efficacious than urethral dilatation;
hence, both options are valid.
Clinical tip Planning
management
A number of factors need to be
taken into account when planning
management of patients with
urethral strictures, including:
● Stricture characteristics: length,
location, calibre, associated
problems (e.g. balanitis xerotica
obliterans, hypospadias)
● Patient characteristics: age,
comorbidities, dexterity, severity
of symptoms
● Patient choice: curative or
palliative treatment, long- term
catheter.
14
Assessment of these patients includes history and the use of a patient- reported outcome questionnaire to ascertain symptom severity and bother (e.g. urethral stricture patient reported outcome measure and the Sexual Health Inventory for Men
(SHIM)).
11,12
Clinical examination is typically unremarkable, note should be taken of
lichen sclerosis and the location of the urethral meatus; occasionally periurethral fibrosis is palpable; and digital rectal examination is essential to assess prostate size
and consistency in older men. Urinary flow rate shows a long slow protracted pattern
with a plateau, as shown in Figure 29.1.13 A post- void ultrasound may reveal large
post- micturition residual volumes, which may necessitate more urgent management.
Expert comment Assessment of urethral strictures
Symptoms and flow rates are poor measures of urethral calibre. There is no reduction in uroflow until
the calibre of the urethra is <11 French gauge.15 With a normally functioning bladder, a stricture does
not usually become manifest until the stricture is very tight.
Retrograde urethrography is essential to delineate the full length of the urethra. It is not possible to
comment on the status of the posterior urethra on a retrograde urethrogram. Only an antegrade or
voiding urethrogram delineates the posterior urethra. Voiding cystourethrography can be performed
as adjunct, distending the urethra proximal to the stricture.9 This is clearly easier in patients with a
suprapubic catheter in situ. In some situations, flexible cystoscopy is of value to visibly assess the state
of the urethral wall in terms of diseases such as lichen sclerosis and it will also provide an impression
rigidity of radiologically non- stenosed regions. This aids preoperative planning in terms of the likely
need for grafting, the length of graft that may be required, and the surgical approach.
Follow- up with flexible cystourethroscopy after patients undergo a urethroplasty enables early
identification of recurrence, morphologic characterization of the recurrence pattern, and, thus,
determination of required intervention.
16
Generally, endoscopic treatment is performed as first line for short bulbar strictures; for those with longer strictures, particularly in the penile urethra, a primary
urethroplasty may be more appropriate. If primary endoscopic treatment fails, further
endoscopic intervention is considered highly likely to fail and hence is palliative in
nature. In general, patients wishing to pursue a second endoscopic intervention should
be instructed to perform clean ISD postoperatively to maintain urethral patency.
Reconstruction for bulbar strictures is almost always a single- stage urethroplasty.
Short strictures may be treated with excision and end- to- end anastomosis or a nontransecting excision and anastomosis. Longer strictures require a stricturotomy and
augmentation with buccal mucosal graft (BMG). The stricturotomy may be made on
the dorsal, ventral, or lateral aspect of the urethra. The grafts are typically laid on
to the stricturotomy.17 A systematic review by Mangera et al. found no significant
difference in average success rates between the various techniques for single- stage
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Table 29.2 A comparison of buccal mucosal and skin grafts
Buccal mucosa Skin
Full thickness— no contraction Split thickness— contracts
Full thickness— good take Full thickness— poor take
Abundant vessels between dermal and
subdermal plexus
Fewer vessels between dermal and
subdermal plexus
Hairless Hairy
Used to being wet or dry Not used to being wet
Limited supply Limitless supply
Durable Penile skin: 20 years; scrotal skin: 10 years
bulbar urethroplasties.18 Penile strictures typically require a two- stage substitution
urethroplasty usually using BMG. Single- stage urethroplasty can also be also performed although the recurrence rate is felt to be higher with the latter in penile urethra.
Historically, penile or scrotal skin flaps and grafts were used for augmentation
procedures. Bladder mucosa grafts were also tried briefly, before being abandoned.
BMG was originally described >100 years ago but popularized in the contemporary
era as the graft of choice following Burger’s report in 1992.19 Table 29.2 provides a
comparison of skin and BMG for urethroplasties.
Learning point Graft uptake
Several factors negatively influence successful ‘take’ of a graft, these include an inadequately prepared
graft (too thick, fatty) or bed, poor vascularity, and infection. Care must be taken to ensure the chance
of ‘take’ is optimized.
There are three main stages of graft uptake:
1. Imbibition: first 48 hours. Where the graft receives nutrients from the plasma through direct contact.
2. Inosculation: day 2– 3. Where there is an establishment of communication channels between
adjacent blood vessels.
3. Vascularization: day 3– 7. Exact mechanism unknown. Angiogenesis occurs with anastomosis
between donor site and graft.
20
Expert comment Qmax
and symptoms
Patients with a Qmax >10 mL/ s
typically do not have troublesome
symptoms and have a low
likelihood of developing
complications and as such may
be suitable for a watch- and- wait
approach. Those with a Qmax of
5– 10 mL/ s are more likely to
develop a urinary tract infection
and if this were the case, then
intervention would be warranted.
A Qmax <5 mL/ s indicates
troublesome symptoms and
complications are common and as
such should be treated.
Evidence base Grafts versus
flaps
A meta- analysis by Wessells and
McAninch showed no difference
in cure rate between the use of
grafts and flaps. Thus, factors once
believed to be less important (e.g.
scarring, time taken to harvest,
donor site morbidity) came to the
forefront when deciding which to
use, making grafts preferable.
9
21
Prognosis
Success rates of urethroplasty are quoted at 85– 90% for bulbar urethroplasties and
around 80% for penile urethroplasties. With regard to bulbar strictures, dorsal and
ventral onlay procedures carry similar success rates of 88.4% and 88.8% respectively.
Future directions The OPEN study
The OPEN study is a randomized, open label, superiority trial of ‘OPen urethroplasty versus
ENdoscopic urethrotomy’ for recurrent bulbar urethral strictures (after prior minimally invasive
treatment). The long- anticipated results were recently published and while urethroplasty had a lower
rate of reintervention (15%), the difference between it and urethrotomy (29%) was far lower than
anticipated. The success of urethrotomy was much higher than anticipated. The question has to be
posed as to the case selection for entry into this study and whether all patients who entered had
a similar profile to that expected for a patient for whom urethroplasty is recommended (e.g. failed
urethrotomy). Although this study raises some interesting questions, reconstruction in expert hands
remains the best long- term solution for patients seeking the best chance of a cure.
22
Clinical tip DVIU for initial
presentations
In summary, a DVIU is indicated
with curative intent at first
presentation for short bulbar
strictures. This carries around a
50% cure rate. If unsuccessful, the
course of further treatment (cure vs
palliation) should be determined
by involving the patient. If cure is
23
the aim, urethroplasty should be
considered.
288 Challenging Concepts in Urological Surgery
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A final word from the expert
Urethral strictures have been recognized as a considerable source of morbidity for thousands
of years. The classic paradigm has been to undertake minimally invasive treatment by way of
urethral dilatation and latterly urethrotomy, followed by palliation with intermittent dilation in
refractory cases. In the modern era, surgical reconstruction has become the accepted treatment
option in refractory cases and was championed by pioneers such as Richard Turner- Warwick
and John Blandy among others. In recent years, attempts have been made to better define
the place of minimally invasive treatments and reconstruction in the treatment algorithm for
anterior urethral stricture disease; however, this has been hampered by the lack of any highlevel evidence.
References
1. Department of Health. NHS reference costs. http/ www.dh.gov.uk/ en/
Publicationsandstatistics/ Publications/ PublicationsPolicyAndGuidance/ DH_ 111591
2. Department of Health. NHS Hospital Episode Statistics. http:// www.hesonline.nhs.uk
3. McMillan A, Pakianathan M, Mao NH, Macintyre CC. Urethral stricture and urethritis in
men in Scotland. Genitourin Med. 1994;70(6):403– 405.
4. Schenkman NS, Manger JP. Male urethra anatomy. Medscape. 2016. https:// emedicine.
medscape.com/ article/ 1972482- overview#a2
5. Nacey JN. Urinary catheter toxicity. NZ Med J. 1991;104(918):355– 356.
6. Lumen N, Hoebeke P, Willemsen P, De Troyer B, Pieters R, Oosterlinck W. Etiology of urethral stricture disease in the 21st century. J Urol. 2009;182(3):983– 987.
7. Kulkarni SB, Barbagli G, Kulkarni JS, Romano G, Lazzeri M. Posterior urethral stricture
after pelvic fracture urethral distraction defects in developing and developed countries, and
choice of surgical technique. J Urol. 2010;183(3):1049– 1054.
8. Chambers RM, Baitera B. The anatomy of urethral stricture. Br J Urol. 1977;49(6):545– 551.
9. Mundy AR, Andrich DE. Urethral strictures. BJU Int. 2010;107(1):6– 26.
10. Thompson H. The Pathology and Treatment of Stricture of the Urethra Both in the Male and
the Female. London: John Churchill; 1865.
11. Kluth, LA, Dahlem R, Becker A. Validation of a patient- reported outcome measure (PROM)
for urethral stricture surgery: a prospective study at a German tertiary care center. Eur Urol
Suppl. 2015;14(2):e954a.
12. Benson CR, Hoang L, Clavell- Hernández J, Wang R. Sexual dysfunction in urethral reconstruction: a review of the literature. Sexual Med Rev. 2018;6(3):492– 503.
13. Arya M, Shergill I, Fernando H, et al. Viva Practice for the FRCS(Urol) and Postgraduate
Urology Examinations. 2nd ed. Masterpass. Boca Raton, FL: CRC Press; 2018.
14. Steenkamp JW, Heyns CF, Dr Kock ML. Internal urethrotomy vs dilatation as treatment for
male urethral strictures: a prospective randomized comparison. J Urol 1997;157(1):98– 101.
15. Smith J. Urethral resistance to micturition: British Association of Urological Surgeons Prize
Essay. BJU Int. 1968;40(2):125– 156.
16. Goonesinghe SK, Hillary CJ, Nicholson TR, Osman NI, Chapple CR. Flexible
cystourethroscopy in the follow- up of post urethroplasty patients and characterisation of
recurrences. Eur Urol. 2015;68(3):523– 529.
17. Patterson JM, Chapple CR. Surgical techniques in substitution urethroplasty using buccal
mucosa for the treatment of anterior urethral strictures. Eur Urol. 2008;53(6):1162– 1171.
18. Mangera A, Patterson JM, Chapple CR. A systematic review of graft augmentation
urethroplasty techniques for the treatment of anterior urethral strictures. Eur Urol.
2011;59(5):797– 814.
19. Burger RA, Muller SC, el- Damanhoury H, et al. The buccal mucosal graft for urethral recon-
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struction: a preliminary report. J Urol. 1992;147(3):662– 664.
20. Bryk DJ, Yamaguchi Y, Zhao LC. Tissue transfer techniques in reconstructive urology.
Korean J Urol. 2015;56(7):478– 486.
21. Wessells H, McAninch JW. Use of free grafts in urethral stricture reconstruction. J Urol.
1996;155(6):1912– 1915.
22. Andrich DE, Leach CJ, Mundy AR. The Barbagli procedure gives the best results for patch
urethroplasty of the bulbar urethra. BJU Int. 2001;88(4):385– 389.
23. Goulao B, Carnell S, Shen J, et al. Surgical treatment for recurrent bulbar urethral stricture:
a randomised open- label superiority trial of open urethroplasty versus endoscopic urethrotomy (the OPEN Trial). Eur Urol. 2020;78(4):572– 580.
289Case 29 Urethral stricture disease
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30
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CASE
Urethral diverticulum
Anudini Ranasinghe and Tamsin Greenwell
Expert commentary Jeremy Ockrim
Case history
A 34- year- old woman was referred by her local urologist to our tertiary unit for excision of a complex recurrent urethral diverticulum (Figure 30.1a). She had undergone
initial excision of the diverticulum and concomitant insertion of a rectus fascial sling
for associated stress urinary incontinence (SUI) 5 years earlier.
She gave a 12- month history of recurrent urinary tract infections (UTIs), frequency
of micturition, urge incontinence, and incomplete emptying requiring intermittent selfcatheterizing eight times per day. She also complained of vaginal pain and dyspareunia, especially during attempts at penetrative sexual intercourse.
Learning point Histopathology of urethral diverticulum
Urethral diverticula are rare entities affecting between 0.02% and 6% of the female population,
although they are found in up to 40% of women undergoing investigation for unexplained lower
urinary tract symptoms in specialist centres.
First described by William Hey in 1805, they are localized, epithelium- lined urethral outpouchings.
Histologically, they are difficult to distinguish from paraurethral cysts. Their lining is composed of
squamous epithelial cells in 42%, columnar epithelial cells in 32%, a combination of both squamous
and columnar cells in 18%, and cuboidal cells in 14%. The majority of diverticula (77%) show signs of
inflammation or ulceration.
Learning point Causes of urethral diverticulum
Most urethral diverticula are acquired and presumed to arise from rupture of chronically obstructed
and infected periurethral glands into the lumen of the urethra.
urethral diverticula are vaginal birth trauma and previous vaginal or urethral surgery. In recent years,
bladder outlet obstruction (BOO), particularly in the form of bulking agents, and mid- urethral tapes/
slings have been implicated in the development of urethral diverticula.
6
3
7,8
Risk factors for the development of
9– 12
1,2
4,5
Learning point Signs and symptoms of urethral diverticulum
The classic description of symptoms from a urethral diverticulum have been described as dysuria,
dyspareunia, and urinary dribbling. However, this triad is only present in approximately 25% of
patients,3 with the majority presenting with non- specific symptoms such as recurrent UTIs, anterior
vaginal pain, swelling, discharge, or urgency lower urinary tract symptoms. Their non- specific clinical
presentation combined with their relative rarity, means that the diagnosis is often delayed.13 It has
been reported that the average delay in diagnosis ranges from 11 to 72 months.
3,13
In addition to
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bothersome presenting symptoms, there is also a long- term risk of malignant transformation in
urethral diverticula in up to 9%.
Urethral diverticula can pose both a diagnostic and surgical challenge and so a high index of
suspicion is required for timely and successful diagnosis and subsequent surgical treatment in
experienced hands.
Awareness of this diagnosis is important, as many patients suffer symptoms for years before the
diagnosis is made and referral made. Additionally, the risk of associated carcinoma arising in
urethral diverticula is low but significant. Patients must be counselled of a 1– 9% long- term risk if the
diverticulum is left untreated and for most patients this is a compelling reason for surgical excision.
Expert comment Diagnosis of urethral diverticula
The clinical diagnosis of urethral diverticula is challenging. The diagnosis is found in direct proportion
to ‘the avidity with which it is sought’. While some patients have obvious periurethral swellings, in
many cases the diagnosis is dependent on imaging. While ultrasound, voiding computed tomography
urethrography, and video urodynamic studies (VUDS) have all been described, fine- slice magnetic
resonance imaging (MRI) has now been established as the modality of choice with the greatest
sensitivity and offering the greatest anatomical detail for subsequent surgical planning. We also
perform VUDS as standard to assess preoperatively for bladder and outlet function. This enables us
to counsel the patients on symptom cause and predict symptom resolution following intervention.
We can quantify the risk of postoperative (stress) urinary incontinence dependent on the diverticulum
size, position, and configuration (simple, partial, or complete horseshoe configurations) along with the
preoperative VUDS findings.
3
The patient was investigated with an T2- weighted, small field of vision, post- void
pelvic MRI (urethral diverticulum protocol) which showed a recurrent, dorsal, large
horseshoe diverticulum surrounding the urethra for 300° from 3 o’clock to 5 o’clock
position (Figure 30.1b) measuring 2.0 × 2.0 × 1.8 cm. The superior portion of a
previous Martius fat pad was also demonstrated. She had VUDS, which demonstrated
severe detrusor overactivity with peak pressures of 74 cmH2O with leak. SUI was not
shown but severe BOO with a Pdet Qmax of 70 cmH2O for a Qmax of 6 mL/ s (Solomon
Greenwell BOO Index 58),14 and a post- void residual of 200 mL (Figure 30.1c). MRI and
VUDS are standard investigations in our unit for all patients with urethral diverticulum.
A transrectal ultrasound was also performed in an attempt to delineate the path
of her rectus fascial sling behind the pubis and relationship to the diverticulum.
Ultrasound did not identify the sling but did demonstrate the circumferential diverticulum surrounding the proximal to mid urethra.
Her case was discussed at the multidisciplinary team meeting. Her symptom complex was considered to be a consequence of her urethral diverticulum. It was possible
that the diverticulum had recurred as a consequence of BOO from the rectus fascial
sling, although it was impossible to exclude a persistent/ recurrent urethral diverticulum as the primary cause. Detrusor overactivity was felt to be consequent to BOO.
The patient had extensive counselling regarding the options for managing her
symptomatic recurrent complex urethral diverticulum. She was offered the options of
the following:
1. Conservative management with observation and/ or anticholinergic or beta- agonist;
or botulinum toxin to treat her urgency incontinence symptoms. She would continue
to be catheter dependent. Her urgency symptoms would be unlikely to completely
resolve, and her pain/ dyspareunia would persist. There is a risk of up to 9% of
293Case 30 Urethral diverticulum
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Figure 30.1 Clinical assessment and investigation of urethral diverticula. (a) A large urethral diverticulum
seen bulging behind the urethral meatus. (b) MRI scan showing a recurrent, dorsal, large horseshoe
diverticulum surrounding the urethra for 300° from 3 o’clock to 5 o’clock. (c) Video cystometrography
showing detrusor overactivity and BOO.
malignant transformation with untreated urethral diverticula.13 This would require
annual follow- up with vaginal examination and MRI pelvis, although MRI surveillance for urethral carcinoma is unproven.
2. Marsupialization of the diverticulum— this may reduce the bulk and infections
but risks creating a fistula between the urethra and the vagina and persistent
leak. There would be no guarantee that her outflow obstruction and catheter
dependency would resolve. The risk of malignant transformation would not
change.
15
3. Excision of the recurrent urethral diverticulum with urethrolysis and Martius
labial fat pad interposition— considered the standard of management for urethral
diverticula.
Expert comment Risk of urethral diverticulum excision
There is a 98% chance that the diverticulum can be completely excised (2% chance that it may
recur) and a 1– 2% chance of the patient developing a new urethrovaginal fistula consequent to the
excision.16 She was informed of a 80– 90% chance of being free of recurrent infections, >90% chance
of resolution of her vaginal pain and dyspareunia, a 70– 90% chance of being relieved of her outflow
obstruction, and consequently a >50% chance of her detrusor overactivity, the cause of her urge
incontinence, settling.
16
16
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