Urethral stricture

Introduction to urethral stricture Urethral stenosis refers to the abnormal urinary tract of any part of the urethra, which causes urinary dysfunction caused by increased resistance in the urethra. More common in men. According to the cause, urethral stricture can be divided into congenital urethral stricture, inflammatory urethral stricture and traumatic urethral stricture. The hypertrophic fibrous tissue replaces the normal urethral sponge to form a scar, which causes the urethra and its surrounding tissues to contract, resulting in urethral stricture. basic knowledge The proportion of illness: 0.012% Susceptible people: no specific population Mode of infection: non-infectious Complications: urinary tract infection, acute epididymitis, urinary fistula, inguinal hernia, chronic renal failure

Cause of urethral stricture

Traumatic urethral stricture (15%):

Traumatic urethral stricture is actually a late complication of urethral trauma, the most common, with the largest urethral stricture in the ball, accounting for about 50%, the posterior urethra is about 40%, the drape is at least 10%, and the trauma includes penetrating injury. Gunshot wound, stab wound), blunt injury (riding cross-injury, penile rupture) and crush injury (pelvic fracture), the first two injuries are often vulnerable to the anterior urethra, the latter injury can damage the posterior urethra For the shear injury of the membrane or the laceration between the bulbs, and many combined injuries, some patients with cross-injury suffered from mild injuries and did not seek medical treatment in time. Most of the symptoms of urethral stricture occurred after 5 to 7 years. Some patients are also found when the condition requires a catheter.

Iatrogenic injury (10%):

Mostly located in the anterior urethra scrotum, between the penis junction and the urethra of the sacral membrane, due to urinary tract manipulation or urethral compression necrosis or chemical stimulation of the indwelling catheter, the damage of urinary pancreatic enzyme to the urethral mucosa after pancreas transplantation was recently discovered. Can cause urethral stricture, endoscopic operation time is the most important cause of iatrogenic urethral stricture; in addition to the chemical toxicity of the urinary catheter, the bacteria easily adhere to the surface of the urinary catheter, forming a retrograde infection; The ischemic necrosis occurs in the compression of the physiologically curved part, and it is easy to form a stenosis.

Inflammatory (12%):

Inflammatory urethral stricture is caused by specific or non-specific urinary tract infection. The specific infection is more common with gonorrhea urethral stricture, followed by tuberculosis. In non-specific infection, the external urethra caused by repeated foreskin balanitis and Penile urethral stricture is more common, recurrent gonorrhea urethritis, the urethral wall forms a wide range of scar tissue, can be segmental or long urethral stricture, scars deep into the urethra or even the urethra surrounding tissue causes urethral lumen occlusion, Clinical treatment is quite tricky.

Congenital (8%):

The congenital urethral stricture is more common, and the urethral valve, fine hypertrophy, congenital narrowing of the urethral lumen, phimosis, etc. can be seen. Urethral stenosis can be divided into simple urethral stricture and complicated urethral stricture according to the length of the stenosis and the presence or absence of complications. Complex urethral stricture includes: stenosis length in the anterior urethra more than 3cm and posterior urethra more than 2cm; more than two stenosis Segment; accompanied by stones, diverticulum, inflammatory polyps, urethritis or inflammation around the urethra; chronic urinary leakage, accompanied by false tracts; urethral sphincter dysfunction; severe pelvic deformity or complicated pubic osteomyelitis and high near the bladder neck Stenosis of the urethra.

Pathogenesis

The normal male urethra is covered by pseudostratified columnar epithelial cells located on the basement membrane. Under the basement membrane is a vascular sinus-rich corpus cavernosum and a connective tissue layer of smooth muscle fibers. The main cellular component of this connective tissue is fibroblast. The cells and extracellular matrix are mainly collagen fibers. After wound or inflammation, fibroblasts activate and proliferate. The rate of synthesis of collagen fibers I is faster than that of collagen fibers III, making the ratio of collagen III to collagen I lower than that of normal urethra. Cavernous body, dilatation and compliance are reduced, urethral lumen formation is narrow, and after stenosis is formed, the tension at the proximal end of the stenosis is higher than that at the distal end during urination, and the ability of fibroblasts to synthesize collagen fibers is different under different tensions. In the case of hypertonicity, the synthesis ability is much greater than that in the case of hypotonic, long-term repeated mechanical stimulation of urination, urinary tract stenosis is further aggravated, and in addition, the proximal urethra expands due to high pressure during urination, and residual urine appears in the dilated urethra. Poor drainage and urinary tract mucosal blood transport, prone to infection, urethral mucosal rupture can occur during high pressure urination, Since urinary extravasation, and thus the occurrence of inflammation around the urethra, abscess around the urethra, urinary tract infections around is bound to narrow further.

Urethral stricture prevention

1. Adjust daily life and workload, and regularly carry out activities and exercise to avoid fatigue.

Urethral stricture complications Complications, urinary tract infection, acute epididymitis, urinary fistula, inguinal hernia, chronic renal failure

Urethral stricture can often be complicated by recurrent bladder, infection around the urethra, upper urinary tract infection and reproductive system infection, and acute testicular epididymitis, scrotum swelling, pain; complicated acute prostatitis when there is pain, accompanied by systemic symptoms such as Chilling, high fever, elevated white blood cells, cellulitis around the urethra manifested as perineal redness, tenderness, formation of abscess can form a urinary fistula after the formation of abscess, urinary fistula located in the distal part of the external sphincter only urinary urination when there is urine overflow, located near The endurance of the urine continues to overflow, long-term dysuria can be complicated by inguinal hernia, anorectal prolapse, etc., can also cause upper urinary tract water, and eventually appear chronic renal failure.

Symptoms of urethral stricture Common symptoms Urethral thickening Hard urinary dysfunction Poor urinary urinary tract rupture dysuria and urinary retention urinary vulva burning... Urinary incontinence urinary urgency Urinary calculi

symptom

1, dysuria

Dysuria is the most common symptom of urethral stricture, which can be mild or severe, and is related to the degree of urethral stricture.

2, bladder irritation and bladder decompensation

It is characterized by frequent urination, urgency, urination, and residual urine, eventually resulting in urinary retention or filling incontinence.

Physical examination:

1 urethra palpation, anterior urethral stricture can reach the stenosis, pay attention to its length, with or without tenderness, urethral secretions and their traits.

2 digital rectal examination, pay attention to the prostate and posterior urethra, if there is suprapubic bladder fistula, you can use the urethral probe through the fistula into the bladder neck to the posterior urethra to help determine the proximal end of the urethral stricture.

3 urethral probe examination to determine the location, length and extent of the stenosis.

The most common symptoms of patients with urethral stricture are obstructive urinary symptoms or urinary tract infections (such as prostatitis and epididymitis). Individual patients may have urinary retention. If asked carefully, most patients have long-term development before they develop complete obstruction. Symptoms of dysuria, the diagnosis of urethral stricture can be determined based on medical history, clinical manifestations and physical examination, but the location, length, extent, and presence or absence of false tract, diverticulum, stones, and sacral density (cavernous body) must be determined. Fibrosis).

Types of

Urethral stricture can be divided into sputum and organic; the latter includes both congenital and acquired.

First, spastic urethral stricture

This is a temporary phenomenon caused by the contraction of the external urinary sphincter. The cause of the infection may be urethritis, urethral stones, application of the urethra or abnormal libido, and sometimes lesions in the perineum, rectum and pelvis. Sexual stimulation, or due to mental factors, urethral fistula occurs in the membrane, so it is indistinguishable from the stenosis of the ball and membrane. When a blunt instrument encounters a blockage in the urethra (such as a catheter) , cystoscopy) can be applied with light pressure continuously, such as urethral stricture, the urethra often suddenly relax and allow the device to pass, under anesthesia, spastic stenosis can be completely relaxed without obstruction, bladder urethrography for diagnosis Very helpful, comprehensive treatment of spastic stenosis, including deduction of incentives, hot water bath, sedative painkillers and antispasmodic agents, acupuncture treatment when bladder overfilling, if necessary, catheterization.

Second, organic stenosis

It is more common in clinical practice.

1, congenital stenosis

Common in the urethra outside the stenosis, often accompanied by foreskin is too long or phimosis, urethral fissure or hypospadias external urethra is often narrower than normal, anterior urethral valve often spacer valve to form a double-chamber anterior urethra deformity, and then There is a small hole in the center of the urethral valve. The urethral stenosis is more common in the junction of the ball and the membrane and the rear end of the scaphoid.

2, acquired stenosis

According to the reasons can be divided into traumatic stenosis and inflammatory stenosis, trauma is the most common cause of urethral stricture, common in perineal riding cross-injury, pelvic fracture caused by urethral injury and urethral injury caused by instrument operation, when the urethra is affected When the heavier trauma affects the submucosa and parietal layer, the urethral muscle layer and its surrounding fascia have changes such as congestion, edema and hemorrhage. During the repair process, the injured tissue forms a fibrotic change. When the scar contracts, the urethral cavity is narrow. Therefore, urethral stricture often occurs several months after injury. In general, longitudinal wounds are less likely to form scar stenosis.

Inflammatory stenosis is seen in gonorrhea, urethral tuberculosis or non-specific urethritis. In acute urethritis, the submucosal and glandular tissues are infiltrated by inflammation. During the chronic period, inflammation is gradually absorbed, and fibrosis is formed to cause urethral stricture. The stenosis occurs more than 1 year or several years after acute urethritis. The urethral stricture caused by inflammation is more extensive than that caused by trauma. The scar tissue is more, the treatment is difficult, the catheter is indwelled, the foreign body in the urethra, the stone, the diverticulum are Can induce urinary tract infection, phimosis secondary to the foreskin stenosis caused by urethral stricture, often delayed treatment, inflammation can spread backward, resulting in long stenosis of the anterior urethra, regardless of trauma or inflammatory urethral stricture, in the narrow proximal urethra Due to the expansion of water, urine infection causes severe fibrosis, which can aggravate the extent and extent of urethral stricture. When the urethra is narrow, the urethral tube is narrow, but a few patients can still pass the catheter or urethral probe smoothly, but because of the surrounding scar The oppression, dysuria, some people call it "elastic urethral stricture."

Symptoms of urethral stricture may vary depending on the extent, extent and development process. The main symptoms are dysuria, difficulty in urinating at the beginning, prolonged urination, divergence of urine, gradual thinning of the urinary line, shortened range or even Drip-like, when the detrusor contraction can not overcome the urethral resistance, residual urine increases or even overflow urinary incontinence or urinary retention, urethral stricture often accompanied by chronic urethritis, at this time the urethra often has a small amount of purulent secretions, mostly in In the morning, the urethral opening was closed by 1, 2 drops of secretions, called "morning drops". The urethral dilatation at the proximal end of the stenosis was easy to cause repeated urinary tract infection due to urinary retention and infection, periurethal abscess, urethral fistula, Prostatitis and epididymis, followed by obstruction caused by pelvic ureteral hydrops and recurrent urinary tract infections eventually lead to renal dysfunction and even uremia.

Examination of urethral stricture

1, imaging examination

(1) urethrography: can more clearly show the stenosis, extent, length and various complications, provide basis and reference for surgical treatment, for anterior urethral stricture, retrograde urethrography can meet the diagnosis, for posterior urethral stricture should be Urinary bladder urethra angiography, filling the proximal urethra of the stenosis, such as the application of two angiography, can obtain more satisfactory results, such as hydronephrosis, CT examination to understand the function and morphology of the kidney.

(2) B-ultrasound: can clearly distinguish the urethral lumen, the cavernous tissue and the level around the urethra, so it can clearly diagnose the length of the stenosis, the extent and the thickness of the scar tissue around the stenosis, and the effect of transurethral ultrasound is better. .

2, urethroscopic examination

Can confirm the condition of the lesion, and can carry out the necessary endoscopic surgery at the same time.

When the upper urinary tract infection is combined, the white blood cells in the blood increase, and the urine can have red blood cells, white blood cells and pathogenic bacteria.

Diagnosis and differentiation of urethral stricture

diagnosis

Diagnosis can be based on the cause, symptoms and related tests.

Differential diagnosis

First, benign prostatic hyperplasia is a common disease caused by endocrine disorders in older men, mainly due to the enlargement of the prostate gland, leading to urinary dysfunction in the urethral cavity, manifested as dysuria, weak urine flow, no line, short range, In elderly cases can be confused with urethral stricture, but often no history of trauma, history of chronic urethritis, rectal examination can touch the surface smooth, tough, enlarged prostate, where the intervertebral groove becomes shallow or disappear, cystoscopy can be seen in the middle of the prostate Or both sides of the lobes into the cavity, bladder urethra angiography see the bottom of the bladder elevated, and has a negative; the posterior urethra is extended and enlarged.

Second, bladder neck contracture is the urinary tract obstruction caused by the proliferation of bladder neck muscle fiber tissue, dysuria, fine urine flow, etc., but no trauma, history of inflammation, rectal examination can touch the bladder neck lumps, urethral probe examination At the time, there was a feeling of tightness at the neck of the bladder. The cystoscopy revealed a narrow neck and neck, a posterior ridge, a triangular area, and a concave bottom.

Third, urethral tumors urethral tumors often cause dysuria, urinary flow and other dysuria, but often progressive, more accompanied by urethral blood secretions, primary hematuria, no history of trauma or inflammation, palpation along the urethra or In the rectal examination, the local urethral mass may be touched, there is tenderness, or the visible mass is exposed in the urethra. The urethral angiography may show the urethral filling defect, the urethroscopic examination shows the tumor, and if necessary, the biopsy is taken.

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