An urethral stricture is defined as a shortening of the diameter of the urethral lumen by fibrosis as a complication of various pathologies. A strictured and narrowed urethra causes obstruction of the passage of urine. This is clinically manifested as a problem in the micturition-process and thus severely impairs the day to day activities of the patient. Urethral stricture, if it remains untreated, can ultimately affect the bladder, ureters and kidneys, resulting in a permanent loss of the renal function.
Presentation
In the initial phase, the urethral stricture may remain asymptomatic. Symptoms may not occur until the urethral diameter has attained a considerable narrow caliber that impedes the urine flow significantly.
The main symptoms of urethral stricture consist of two types, obstructive and irritative. The most common obstructive urinary symptoms comprise retention of urine and urinary tract infections. Voiding dysfunctions of obstructive types are characterized by an intermittent urinary flow, decreased force of stream despite effort, as well as a feeling of an incomplete evacuation along with terminal dribbling of urine [10]. These symptoms may be progressive in many patients. Double urinary stream, hesitancy, weak urinary stream or recurrent urinary tract infection including prostatitis or epididymitis are other suggestive symptoms [10]. A long-standing untreated urethral stricture can cause renal impairment and hence reduce the quality of life of the patient substantially.
Some patients suffering from urinary retention may be subsequently diagnosed with an urethral stricture. This is not an uncommon event. It is suggested that in the initial phase, an impaired flow caused by urethral narrowing can be overcome by raising the intra-vesical pressure by detrusor hyperactivity to some extent. Finally, these changes causing a high pressure reflux transmitted through the ureters may harm the kidneys and lead to permanent damage of the upper renal system including bilateral kidneys [11]. Some less frequent complications including carcinoma of the urethra, kidney failure, Fournier's gangrene, and atonic bladder have been reported [6].
Workup
A suggestive history, relevant clinical findings, radiological observations and endoscopic evaluation can detect an urethral stricture. Retrograde urethrogram or antegrade cystourethrogram, in the presence of a suprapubic catheter, are the two commonly employed diagnostic approaches. Ultrasonography of the male urethra may also be useful to assess the stricture. It can evaluate the length and the depth of the strictured spongiofibrotic segment. However, only a retrograde urethrography or cystoscopy can precisely locate and demonstrate the extent and depth of an urethral stricture.
Uroflowmetry is another test that can be employed for diagnostic purpose [11]. This investigation provides the data about the urine flow as volume passed per unit of time as well as total stream urination time.
By urethroscopy, the exact location of the stricture can be assessed, but in case the the stricture cannot be circumvented the exact length of the lesion remains uncertain.
Other ancillary diagnostic procedures include abdominal ultrasonography to determine any residual urinary volume in the bladder as well as any hydronephrotic changes already present due to obstructive uropathy.
Treatment
Treatment options for urethral stricture include urethral dilatation, endoscopic internal urethrotomy, open urethroplasty and placement of urethral stents.
- Urethral dilatation: Periodic urethral dilation is a procedure where the stricture is an isolated one, epithelial in nature and not involving deep up to the corpus spongiosum. The target is to achieve adequate dilatation without producing any further scarring. Thus, it may be curative for those groups of patients with superficial strictures. Usually no further treatment is needed.
- Internal urethrotomy: This is an endoscopic procedure where the stricture is incised transurethrally to release scar tissue and widen the lumen. The success of this procedure depends on the epithelialization process after the incision as the possibility of development of an early wound contracture before complete epithelization often reduces the effective lumen caliber. Early scar formation as a result thus can explain the high recurrence rate related to this procedure.
- Open urethroplasty: Primary repair termed open urethroplasty is indicated where the stricture length is about 1-2 cm. This procedure needs removal of the fibrosis along with an end to end re-anastomosis. The basic three steps to avoid recurrence following primary repair are complete removal of the fibrotic portion, end to end tension-free anastomosis, and finally, reconstruction of a widely patent anastomosis.
- Stents: Permanent urethral stents are another option where the strictures are of short-length and located in the bulbar urethra. They are placed endoscopically into the strictured portion so as to provide a patent urethral lumen. They are most appreciated and useful in those circumstances as mentioned above and found to be having a very high acceptance rate.
Of the existing treatment options, the appropriate one has to be chosen by considering all coexisting factors. The decision depends on the nature of the urethral stricture (length or proximity of stricture), recurrence of stricture or allied complicating co-factors.
Dilation of the urethra along with internal urethrotomy performed as a combined procedure is a commonly conducted operation. However, in complicated or recurrent strictures as well as in very long persistent strictures daily self-catheterization is the most appropriate treatment option compared to dilation and endoscopy.
Open urethroplasty is only effective short strictures (<2.5 cm) that are located in the bulbar urethra.
To conclude, short urethral strictures should be initially dealt with an endoscopic internal urethrotomy. In cases of recurrence, open reconstruction is the optimum choice treatment to avoid expanding the defect by repeated procedures like urethrotomies.
Prognosis
The risk of recurrence must be kept in mind whatever treatment option for urethral stricture has been chosen. Long-term outcome following surgery depends on various factors like the length of the strictured portion, location of the stricture as well as the number of previous procedures adopted [7] [9]. A comparative study between internal urethrotomy and urethral dilation found the two procedures to be equally effective in the treatment of male urethral stricture when applied as initial treatment [7]. The recurrence rate of an urethral stricture is found to be directly related to the length of the pretreatment strictured portion. Post treatment recurrence rates at the end of 12 months are found to be 40%, 50%, and 80% while pretreatment stricture lengths were of less than 2 cm, 2-4 cm, and greater than 4 cm respectively. The need for a repeated procedure may be as high as 75% at the end of 48 months follow-up for strictures of 2-4 cm length. A follow-up data at the end of five years after placement of urethral stenting in recurrent strictures revealed a moderately high success rate of 84% as well as a very good score of patient satisfaction [8].
Urethral stricture shows more severe complications in the form of acute retention of urine, Fournier's gangrene, bladder atony and even renal failure as long-term squeal [6]. The treatment procedures for urethral stricture hold many inherent complications which could amplify the burden.
Etiology
An urethral stricture may result due to different causes. Any infection or any procedure that has the potentiality to damage the urethral epithelium or the or corpus spongiosum may lead to the development of a stricture. Common causes of development of urethral stricture are:
- Traumatic or iatrogenic: Both of them are acquired causes as in almost all cases an inciting factor can be identified [1] [2]. These are the most frequent reasons for the development of urethral stricture. Trauma to the urethra may be a result of a straddle injury or injury acquired following any procedure through the urethra. The main reasons (45%) of urethral stricture are thus iatrogenic and could be as a result from any form of urethral manipulations due to diverse reasons (trauma received during urinary catheterization, different transurethral manipulations and instrumentations, surgery for hypospadias, prostate operation, brachytherapy, etc.) [1] [2].
- Idiopathic: Almost in 30% cases of urethral strictures no preceding event can be pointed out [1]. It was thought to be due to a consequence following some form of forgotten minor trauma (e.g. acquiring a perineal injury while falling over the rod of a bicycle) [3].
- Inflammatory or infectious: Gonococcal urethritis is the most common infectious etiology of urethral stricture. It is found more commonly in high-risk population.
- Malignancy
- Congenital
Epidemiology
Urethral stricture is one of the most commonly encountered urological diseases affecting any age irrespective of sex. Its incidence in males is reported to be 0.9% in developed countries. However, the recurrence rate is quite high [4]. The survey from medicare utilization for men aged 65 years and above revealed the incidences of urethral stricture were estimated to be 0.9% in 2001. This showed a significant decrease from the previous incidence, 1.4% in 1992 [5]. A figure of 193 per 100,000 (0.2%) was found as per the incidences notified from the Veteran Affairs (VA) in 2003 [6].
Pathophysiology
An urethral stricture may be a congenital event. It results due to a developmental defect following an improper adherence of the anterior and posterior urethra. The effective urethral length is found to be short and infection has no role for its pathogenesis.This is, however, an extremely rare condition.
An acquired stricture is caused by any damage to the urethral mucosa by either trauma or infective pathology. These cause the formation of scar tissues and subsequent narrowing of the urethral lumen.
Prevention
Preventive approaches for urethral stricture focus mainly on prevention of urinary tract infection as well as avoidance of any urethral procedure as far as possible.
Previous studies suggest an association between urinary tract infections and urethral strictures. Romero et al showed that out of 175 patients with urethral stricture, 63 (36%) had evidence of urinary tract infection [12]. Prevention of blind catheterization is another important step and bougienage of the urethra with the help of an indwelling catheter should be abandoned in patients with retention of urine. These patients often benefit from a suprapubic catheter placement.
Urethral stricture may cause an urinary stasis and lead to an urinary tract infection. Thus, the possibility of any urinary tract infection has to be ruled out in a patient with already diagnosed with urethral stricture as it may further incite an inflammation and worsen the present condition. Any infection of the urinary tract must be treated with appropriate antibiotics, according to laboratory test results [12].
Frequent instrumentation often employed for the diagnostic purpose as well as for the management of urethral stricture can also lead to infection. These may cause retrograde transmission of organism causing urinary tract infection and worsening the condition further.
Summary
Urethral stricture is usually an acquired condition resulting from a shortening of the urethral lumen mostly due to scarring. This leads to an obstructive voiding dysfunction and if not treated properly, can have a major impact on the urinary bladder, ureters and kidneys. An urethral stricture can be a squeal of diverse pathological conditions and may have a wide range of presenting symptoms. It may remain asymptomatic in some patients, only diagnosed accidentally, or may cause severe discomfort due to urinary retention. A detailed anatomical and pathophysiological knowledge of the urinary system is necessary before opting any procedure to create an effective outflow tract of the urinary bladder for treating the stricture.
Patient Information
An urethral stricture is most commonly developed as a result of previous injury or infection. Sexually transmitted infections seldom cause urethral stricture. Often no cause may be detected. Strictures are rarely congenital. Less forceful urination despite a full effort or experiencing a double stream of urine is an indicator of a mild stricture. Severe forms of strictures may cause a complete obstruction of the outflow of urine leading to retention. As there is an incomplete evacuation of the bladder and urinary stasis urinary tract infections are often the consequence of a stricture. Treatment of this condition is done by the urologist who dilates the urethra and widens the strictured portion by inserting an instrument under anesthesia. In some cases the strictured portion has to be excised by inserting an instrument through the urethral lumen.
References
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- Fenton AS, Morey AF, Aviles R, Garcia CR. Anterior urethral strictures: etiology and characteristics. Urology. 2005 Jun;65(6):1055-8.
- Park S, McAninch JW. Straddle injuries to the bulbar urethra: management and outcomes in 78 patients. J Urol. 2004 Feb;171(2 Pt 1):722-5.
- Anger JT, Buckley JC, Santucci RA, Elliott SP, Saigal CS. Urologic Diseases in America Project. Trends in stricture management among male Medicare beneficiaries: underuse of urethroplasty? Urology. 2011 Feb;77(2):481-5.
- Anger JT, Buckley J, Santucci R, Saigal C, Project UDoA. Trends in stricture mangement among male Medicare beneficiaries: Underuse of Urethroplasty? Presented at the 2008 Society for Urodynamics and Female Urology annual meeting Miami, February 2008. 2008.
- Santucci R, Joyce G, Wise M. In: Urologic Diseases in America. Litwin MS, Saigal CS, editor. US Department of Health and Human Services, Public Health Service, National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases. Washington, DC: US Government Publishing Office, 2004; NIH Publication No. 04-5512; Male urethral stricture disease; pp. 533–551.
- Steenkamp JW, Heyns CF, de Kock ML. Internal urethrotomy versus dilation as treatment for male urethral strictures: a prospective, randomized comparison. J Urol. 1997 Jan. 157(1):98-101.
- Milroy E, Allen A. Long-term results of urolume urethral stent for recurrent urethral strictures. J Urol. 1996 Mar. 155(3):904-8.
- Breyer BN, McAninch JW, Whitson JM, Eisenberg ML, Mehdizadeh JF, Myers JB, Voelzke BB. Multivariate analysis of risk factors for long-term urethroplasty outcome. J Urol. 2010 Feb;183(2):613-7.
- Fenton AS, Morey AF, Aviles R, Garcia CR. Anterior urethral strictures: etiology and characteristics. Urology. 2005 Jun;65(6):1055-8.
- Brandes SB. Totowa: Humana Press; 2008. Urethral Reconstructive Surgery.
- Romero Pérez P, Mira Llinares A. [Urinary infection and urethral stenosis in males]. Actas Urol Esp. 1990 Nov-Dec;14(6):401-6.