Male urethral strictures

Stricture of the male urethra is a polyetiological obstructive lesion that affects the urethral epithelium, corpus spongiosum, and in some cases, paraurethral tissues.

Due to cicatricial changes in the tissues in the walls of the urethra, the diameter of the lumen narrows.

Epidemiology

The frequency of urethral strictures is directly related to the socio-economic and cultural status of the society. In developed countries, the frequency of traumatic and inflammatory urethral strictures is significantly lower than in developing and especially in poor countries. On the contrary, in developed countries this disease occurs after TUR and RP. Military actions cause gunshot and stab injuries to the male urethra. Cultural characteristics of peoples (insertion of foreign bodies into the urethra) determine the frequency of penile strictures of the urethra.

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Causes male urethral strictures

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Anatomy of the urethra

According to the International Anatomical Classification, the male urethra is divided into three segments:

• prostatic (prostatic), passing through the prostate;
• membranous (membranous), surrounded by the urogenital diaphragm;
• spongy (spongy), located from the urogenital diaphragm to the external opening of the urethra.

Considering the characteristics of strictures of various parts of the urethra and the characteristics of surgical tactics and techniques for their treatment, it is inappropriate to use a more detailed anatomical classification:

• prostatic urethra;
• membranous part of the urethra;
• bulbous part of the urethra;
• penile urethra;
• glandular part of the urethra.

Each section of the urethra has its own histological structure characteristics that determine specific features of the occurrence and course of urethral strictures. Thus, strictures of the prostatic section of the urethra occur only with the development of total or periurethral fibrosis of the prostate. Consequently, endoscopic operations on prostatic stricture also involve prostate surgery. Strictures of the membranous section of the urethra are always associated with damage to one degree or another of the urethral striated sphincter, therefore open and endoscopic operations in this area are associated with the risk of urinary incontinence.

New knowledge about the histology of the spongy body and its vascular system explains the specific features of strictures of this localization, their tendency to spread along the wall of the urethra, the development of complications and relapses. It has been established that the spongy body of the bulbous and penile sections of the urethra is an extensive venous plexus, and between the walls of many veins are located lacunar sinuses, the direct connection of which with the arterioles of the bulbous artery {a. bulbaris) explains the immediate erection of the bulbus of the penile section of the urethra as a whole, as well as the head of the penis in response to appropriate stimuli.

This is why spongy fibrosis in inflammatory strictures of the subdiaphragmatic portion of the urethra is a consequence of phlebitis and periphlebitis of the spongy body: a process that never has clear boundaries, but actively progresses in many patients. To a certain extent, this explains the progression of spongiofibrosis, i.e. the expansion of the boundaries of narrowing, including even after successful urethroplasty. This also explains the ineffectiveness of internal optical urethrotomy and resection of the urethra with a standard anastomosis in inflammatory strictures of the urethra.

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What causes urethral strictures in men?

Any lesion of the epithelium of the urethra and corpus spongiosum, resulting in scar formation, can lead to the development of urethral stricture.

Currently, most strictures are of traumatic origin. Thus, blunt or open trauma to the pelvic ring (fractures of the pubic and ischial bones, ruptures of the symphysis and iliac-sacral joints) cause damage to the membranous part of the urethra (distraction rupture as a result of multidirectional ruptures of the muscles and tendons of the urogenital diaphragm, with which the mucous membrane of the urethra is tightly connected).

In addition, damage to the urethra can be caused by direct impact of a broken bone. On the other hand, direct trauma to the perineum can be accompanied by damage to the bulbous urethra by crushing the tissue between the pubic bones and an external traumatic factor.

This group also includes iatrogenic trauma associated with intraurethral manipulations (catheterization, bougienage, endoscopy, endoscopic surgery), as well as with unsuccessful outcomes of open surgery on the urethra for hypospadias and epispadias.

Symptoms male urethral strictures

Urethral strictures are characterized by symptoms of lower urinary tract disease; they are clinically distinct from other obstructive lesions.

The most frequent and especially important symptom is a weak urine stream. With a slowly progressing, gradual development of the disease, micturition symptoms predominate, then postmicturition symptoms join in, and cumulative symptoms appear later than others.

In iatrogenic and inflammatory strictures of the urethra (after endoscopic surgery, surgery on the penis, use of a urethral catheter), pain may be expressed both during urination and during erection and ejaculation. The pain is especially severe with the development of purulent-destructive complications (abscesses, fistulas, etc.).

The clinical picture of traumatic strictures of the urethra is characterized by symptoms of concomitant injuries (pelvic bones, rectum) and their complications (chronic pelvic pain syndrome, impotence, etc.).

Forms

In accordance with modern concepts of urethral strictures, the following classification options are usually used.

By etiological factor:

• traumatic, including iatrogenic;
• inflammatory, including iatrogenic;
• congenital;
• idiopathic.

Comments: iatrogenic stricture is not singled out separately, since it can be both traumatic and inflammatory in its genesis.

According to pathomorphology:

• primary (uncomplicated, previously untreated);
• complicated (relapse, fistulas, abscesses, etc.).

Comments: recurrent stricture is not singled out separately, since it in itself is already a complication of structural disease of the urethra.

By localization:

1. prostatic stricture;
2. membranous stricture;
3. bulbar stricture;
4. penile stricture;
5. capitate stricture;
6. scaphoid stricture;
7. stricture of the external opening of the urethra.

By length:

• short (<2 cm);
• long(>2 cm);
• subtotal spongy (damage to 75-90% of the spongy part of the urethra);
• total spongy (damage to the entire spongy part of the urethra);
• total (damage to the entire urethra).

By quantity:

• single;
• multiple.

By degree of narrowing:

• mild (the lumen is narrowed to 50%);
• moderate (the lumen is narrowed up to 75%);
• severe (the lumen is narrowed by more than 75%);
• obliteration (no lumen).

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Diagnostics male urethral strictures

The main methods for diagnosing urethral stricture include:

1. analysis of the patient's complaints and his anamnesis:
2. examination and palpation of the penis, urethra, scrotum and perineum;
3. digital examination of the anal canal, prostate and rectal walls;
4. retrograde urethrography;
5. antegrade cystourethrography.

General clinical tests of urine and blood, biochemical blood test, in particular determination of serum creatinine concentration.

Retrograde urethrography is performed by the surgeon responsible for the patient's treatment. The method allows determining the location, degree and extent of the stenosis while maintaining the patency of the urethra for the contrast agent. In case of obliteration, only the distal border of the lesion is visualized. In both cases, it is important to immediately perform antegrade (micturition) cystourethrography.

If the urethra is patent, the contrast agent fills the suprastrictural part of the urethra and visualizes the degree of dilation of the latter.

In the case of an obstructed urethra and cystostomy, during tension of the anterior abdominal wall, the contrast agent fills the proximal portion of the urethra up to the stricture, which will allow the extent of obliteration to be determined. The inability to visualize the proximal portion of the urethra in this way makes it advisable to pass a Guyon bougie through the fistula and the neck of the bladder into the prostatic urethra, which also helps to characterize the extent of obliteration.

Thus, urethrography allows in most cases to determine the stricture of the urethra, its location and degree of narrowing, to identify complications (fistulas, stones, diverticula, etc.). The information obtained is usually sufficient to select a treatment method (observation, bougienage, endoscopic or open surgery) and even a surgical treatment method (resection or urethroplasty).

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Treatment male urethral strictures

The main goal is complete cure of urethral stricture and its complications. However, achieving this goal is impossible in some cases.

1. The patient's unwillingness to undergo complex plastic surgery and the patient's choice of a palliative treatment option.
2. The presence of multiple and severe relapses of the disease, excluding the possibility of performing radical reconstruction of the urethra;
3. Treatment of urethral stricture is not always accompanied by the possibility of eliminating complications (infertility, chronic prostate or urinary tract infection, urolithiasis, etc.).

Other goals:

1. improved urination;
2. improving the quality of life.

Prevention

Prevention of inflammatory strictures of the urethra consists in timely and adequate treatment of acute urethritis, primarily of gonococcal origin. In case of traumatic ruptures of the urethra, medical personnel should strictly follow the standard of emergency surgical care, which will certainly create the prerequisites for the optimal result of surgical treatment of future strictures of the urethra.

High quality of transurethral endoscopic surgery of the lower urinary tract and upper urinary tract, as well as high culture of work of medical personnel with urethral catheters are real measures for the prevention of iatrogenic strictures of the urethra.

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Forecast

Short traumatic membranous and bulbous strictures of the urethra are curable in more than 95% of cases by resection of the cicatricial segment with end-to-end anastomosis of the urethra.

In some cases, after resection, anastomotic urethroplasty with a free graft or vascularized flap is necessary. Penile strictures and long urethral strictures of the bulbous segments are curable in 85-90% of cases by substitution urethroplasty.

The best plastic materials are penile skin, buccal mucosa and vaginal membrane. Complicated and recurrent strictures may require multi-stage operations. Reconstruction of the prostatic urethra is associated with the risk of urinary incontinence, and plastic surgery of the glans urethra - with possible cosmetic defects.

Achieving maximum efficiency in the treatment of urethral strictures is not always possible due to the development of a number of complications, the prevention and treatment of which increases the chances of success.

Technical improvements in urethral surgery are needed, but a breakthrough may come from the development of free urethral grafts grown from patient tissue culture.

In the near future, the number of urethral strictures in men will not decrease due to a number of factors (traumatism, infections, iatrogeny). That is why urethral strictures will remain a pressing urological problem for a long time.

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