Urinary tract stricture

Introduction 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 three categories: 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. The most common symptoms of patients with urethral stricture are obstructive urinary symptoms or urinary tract infections (such as prostatitis, epididymitis), and individual patients may have urinary retention. If asked carefully, most patients have long-term symptoms of dysuria before developing complete obstruction. The diagnosis of urethral stricture can be determined based only on medical history, clinical manifestations, and physical examination.

Cause

(1) Causes of the disease

1. Traumatic urethral stricture: 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%, and the drape is at least 10%. . Trauma includes penetrating wounds (gunshot wounds, stab wounds), blunt injuries (riding cross-injury, penile rupture) and crush injuries (pelvic fractures). The first two injuries are often easy to injure the anterior urethra, and the latter injury can damage the posterior urethra by 10%, which is a shear injury in the membrane or a laceration between the bulbs, and there are many combined injuries. Some patients with cross-injury suffered from mild injuries and did not seek medical treatment in time. Most of them had symptoms of urethral stricture after 5 to 7 years, and some patients were only found when the condition required a catheter.

2. Iatrogenic injury: mostly located in the anterior urethra scrotum, penis junction to the urethral urethra, due to urinary tract manipulation or urethral compression necrosis or chemical stimulation of indwelling catheter, recently found in the urine after pancreas transplantation Pancreatic enzyme damage to the urethral mucosa can cause urethral stricture. Long endoscopic operation time is the most important cause of iatrogenic urethral stricture; in addition to the chemical toxicity of the urinary catheter, the bacteria tend to adhere to the surface of the urinary catheter to form retrograde infection; the urethra is in the physiological bending part. Ischemic necrosis occurs in compression, and stenosis is easy to form.

3. Inflammatory: Inflammatory urethral stricture is caused by specific or non-specific urinary tract infection. Gonorrhea urethral stricture is more common in specific infections, followed by tuberculosis; in non-specific infection, due to repeated foreskin balanitis The urethral stricture of the urethra and the penis are more common. Repeated gonorrhea urethritis, the formation of extensive scar tissue in the urethral wall, can be segmental or long-term urethral stricture, scars deep into the urethra or even the urethra surrounding tissue caused by urethral lumen occlusion, clinical treatment is quite tricky.

4. Congenital: The congenital urethral stricture is more common, and the urethral valve, fine sputum hypertrophy, urethral lumen congenital narrowing, phimosis and so on.

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 strictures include: stenosis more than 3 cm in the anterior urethra and more than 2 cm in the posterior urethra; more than two stenotic segments; associated with stones, diverticulum, inflammatory polyps, urethritis or periurethitis; chronic urine leakage with false The presence of the tract; urethral sphincter dysfunction; severe pelvic deformity or complicated pubic osteomyelitis and high urethral stricture close to the bladder neck.

(two) 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, the extracellular matrix are mainly collagen fibers. After trauma or inflammation, fibroblasts activate and proliferate, and the rate of synthesis of collagen fibers I is faster than that of collagen fibers III, so that the ratio of collagen III to collagen I is lower than that of normal urethral sponges, and the stretchability and compliance are reduced. The urethral lumen is narrowed. After the stenosis is formed, the tension at the proximal end of the stenosis is higher than the tension at the distal end during urination. The ability of fibroblasts to synthesize collagen fibers under different tensions is different. When the synthesis ability in high tension is much greater than that in low tension, the mechanical stimulation of urination is repeated for a long time, and the urethral stricture is further aggravated. In addition, when the urination is dilated, the proximal urethra expands due to high pressure, and residual urine appears in the dilated urethra. Due to poor drainage and poor urinary tract mucosal blood flow, infection is prone to occur, and urethral mucosal rupture may occur during high-pressure urination, causing extravasation of urine. In addition, inflammation around the urethra, abscess around the urethra, infection around the urethra will inevitably further aggravate the stenosis.

First, spastic urethral stricture This is a temporary phenomenon, caused by the contraction of the external urinary sphincter. The cause of the induction may be urethritis, urethral stones, application of instruments in the urethra, or abnormal libido. Sometimes it can be a reflex stimulus in the perineum, rectum, and pelvis, or it can be caused entirely by mental factors. The urethral fistula occurs in the membrane, so it is indistinguishable from the narrowness of the spherical portion and the membrane. When a blunt instrument encounters a blockage in the urethra (such as a catheter or a cystoscope), it can be continuously applied with light pressure. If the urethral stricture is paralyzed, the urethra often suddenly relaxes and the instrument passes. Under anesthesia, the stenosis can be completely relaxed without obstruction. Bladder urethrography is helpful for diagnosis. Comprehensive treatment of spastic stenosis, including the release of incentives, hot water bath, sedative painkillers and anti-caries agents. Acupuncture can be used when the bladder is overfilled. Use catheterization if necessary.

Second, organic stenosis is more common in clinical practice.

classification

Congenital stenosis

Common in the urethra outside the mouth is narrow, often accompanied by foreskin is too long or phimosis. The urethral opening of the upper or lower urethra is often narrower than normal. The anterior urethral valve often forms a double-chamber anterior urethra deformity with a septal valve, while the posterior urethral valve has a small hole in the center of the urethral valve. Urethral stenosis is more common at the junction of the ball and the membrane and the posterior end of the scaphoid.

2. Acquired stenosis

According to the reasons, it can be divided into traumatic stenosis and inflammatory stenosis. Trauma is the most common cause of urethral stricture. Common in the perineal riding cross-injury, pelvic fracture caused by urethral injury and device operation caused by urethral cavity damage. When the urethra is subjected to heavier trauma involving the submucosa and parietal layers, 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 fibrous change. When the scar contracts, the urethral cavity is narrow, so the urethral stricture appears more than a few months after the injury. In general, longitudinal wounds are less likely to form scarring. Inflammatory stenosis is seen in gonorrhea, urethral tuberculosis or non-specific urethritis. In acute urethritis, the submucosal layer and the tissues surrounding the gland are infiltrated by inflammation. During chronic phase, inflammation gradually absorbs and forms fibrotic changes that cause urethral stricture. Therefore, inflammatory stenosis often occurs in acute urethritis 1 year or several years later. The urethral stricture caused by inflammation is more extensive than that caused by trauma, and the scar tissue is more and the treatment is difficult. Indwelling catheter, foreign body in the urethra, stones, diverticulum can induce urinary tract infection, phimosis secondary to the foreskin penis inflammation caused by urethral stricture, often delayed treatment, inflammation can spread backwards, resulting in long urethral stricture, Regardless of trauma or inflammatory urethral stricture, the proximal urethra of the stenosis expands due to stagnant water, and the infection of the urine causes severe fibrosis, which can aggravate the extent and extent of urethral stricture. The urethral tube is narrow when the urethra is narrow, but a small number of patients can still pass through the catheter or urethral probe. However, due to the compression of the surrounding scar, dysuria is difficult. Some people call it "elastic urethral stricture".

Symptoms of urethral stricture may vary depending on the extent, extent, and course of development. The main symptom is difficulty urinating. It is laborious to urinate at the beginning, the urination time is prolonged, and the urine is bifurcated. Afterwards, the urinary line becomes thinner, and the range becomes shorter or even dripping. When the detrusor contractes and cannot overcome the urethral resistance, residual urine increases or even overflows urinary incontinence or urinary retention. Chronic urethritis is often associated with urethral stricture. At this time, there is often a small amount of purulent discharge outside the urethra. It is often found in the morning, and the urethral orifice is closed by 1, 2 drops of secretions, which is called "morning drop". The proximal urethral dilatation is prone to repeated urinary tract infections, periurethral abscesses, urethral fistulas, prostatitis, and epididymis due to urinary retention. In turn, pelvic ureteral hydrops caused by obstruction and recurrent urinary tract infections eventually lead to renal dysfunction and even uremia.

Urethral stricture can often be accompanied by recurrent bladder, periurethral infection, upper urinary tract infection and reproductive system infection. When accompanied by acute testicular epididymitis, the scrotum is red and swollen, and there is painful pain in the case of acute prostatitis, accompanied by systemic symptoms such as chills, high fever, and elevated white blood cells. The cellulitis around the urethra is characterized by redness and tenderness of the perineum. After the abscess is formed, the urinary fistula can be worn by itself. The urinary fistula is located at the distal end of the external sphincter. When the urination is only urinating, there is urine overflow in the mouth, and the urine in the proximal end continues to overflow. Long-term dysuria can be complicated by inguinal hernia, anorectal prolapse, etc., can also cause upper urinary tract water, and eventually chronic renal failure.

an examination

Related inspection

Urethral examination for urethral function test

1, imaging examination

(1) urethrography: more clearly showing the location, extent, length and various complications. Provide basis and reference for surgical treatment. For anterior urethral stricture, retrograde urethrography can satisfy the diagnosis. For posterior urethral stricture, urinary bladder urethrography should be performed to fill the proximal urethra of the stenosis. If both angiography are applied at the same time, a more satisfactory effect can be obtained. If you have hydronephrosis, use CT to understand the function and morphology of the kidney.

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

2, urethroscopic examination: can clear the lesions, and can carry out the necessary intracavitary surgery.

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.

Differential diagnosis

First, prostate hyperplasia: is a common disease caused by endocrine disorders in older men. Mainly the enlargement of the prostate gland, which protrudes into the urethral cavity and causes dysuria. It is characterized by difficulty in urinating, weak urine flow, no line, and short range. Older cases can be confused with urethral stricture. But often no history of trauma, chronic urethritis history. The rectal examination can reach a smooth, thick, and enlarged prostate, in which the interstitial becomes shallow or disappears. Cystoscopy revealed a mid-protrusion or bilateral lobes protruding into the lumen. Bladder urethra angiography showed elevation of the bottom of the bladder and had a negative effect; the posterior urethra was prolonged and enlarged.

Second, the bladder neck contracture: is the urinary tract obstruction caused by the proliferation of bladder neck muscle fiber tissue. There are dysuria, fine urine flow and other performance, but no history of trauma, inflammation. The rectal examination can reach the bladder neck lumps. When the urethral probe is examined, there is a feeling of tightness through the neck of the bladder. Cystoscopy showed an annular stenosis of the bladder neck, a posterior ridge-like bulge, a hypertrophy in the triangle, and a depression in the bottom of the bladder.

Third, urethral tumors: urethral tumors often cause dysuria, urinary flow and other urinary dysfunction. But often for progressive exacerbations, more with urethral bloody secretions, primary hematuria. No history of trauma or history of inflammation. When palpation along the urethra or rectal examination, the local urethral mass may be touched, there is tenderness, or a visible mass is exposed in the urethra. Urethral angiography can show urethral filling defects. Tumors can be seen by urethroscopic examination. Take a biopsy if necessary.

1. Difficulties in urination: dysuria is the most common symptom of urethral stricture, which can be light or severe, and is related to the degree of urethral stricture.

2. Bladder irritation and bladder decompensation: manifested as frequent urination, urgency, and urination. The remaining urine gradually appears, eventually resulting in urinary retention or filling urinary 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 the posterior urethra. If there is a suprapubic bladder fistula, the urethral probe can be inserted into the bladder neck through the fistula into the posterior urethra to help determine the proximal end position 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, epididymitis), and individual patients may have urinary retention. If asked carefully, most patients have long-term symptoms of dysuria before developing complete obstruction. The diagnosis of urethral stricture can be determined based only on medical history, clinical manifestations, and physical examination. However, it is necessary to determine the location, length, and extent of the stenosis, as well as the presence or absence of false tracts, diverticulum, stones, and sacral density (cavernous fibrosis).

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 induction may be urethritis, urethral stones, application of instruments in the urethra, or abnormal libido. Sometimes it can be a reflex stimulus in the perineum, rectum, and pelvis, or it can be caused entirely by mental factors. The urethral fistula occurs in the membrane, so it is indistinguishable from the narrowness of the spherical portion and the membrane. When a blunt instrument encounters a blockage in the urethra (such as a catheter or a cystoscope), it can be continuously applied with light pressure. If the urethral stricture is paralyzed, the urethra often suddenly relaxes and the instrument passes. Under anesthesia, the stenosis can be completely relaxed without obstruction. Bladder urethrography is helpful for diagnosis. Comprehensive treatment of spastic stenosis, including the release of incentives, hot water bath, sedative painkillers and anti-caries agents. Acupuncture can be used when the bladder is overfilled. Use catheterization if necessary.

Second, organic stenosis: more common in clinical clinical.

1. Congenital stenosis: common in the urethra outside the mouth is narrow, often accompanied by foreskin is too long or phimosis. The urethral opening of the upper or lower urethra is often narrower than normal. The anterior urethral valve often forms a double-chamber anterior urethra deformity with a septal valve, while the posterior urethral valve has a small hole in the center of the urethral valve. Urethral stenosis is more common at the junction of the ball and the membrane and the posterior end of the scaphoid.

2. Acquired stenosis: divided into traumatic stenosis and inflammatory stenosis according to reasons. Trauma is the most common cause of urethral stricture. Common in the perineal riding cross-injury, pelvic fracture caused by urethral injury and device operation caused by urethral cavity damage. When the urethra is subjected to heavier trauma involving the submucosa and parietal layers, 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 fibrous change. When the scar contracts, the urethral cavity is narrow, so the urethral stricture appears more than a few months after the injury. In general, longitudinal wounds are less likely to form scarring. Inflammatory stenosis is seen in gonorrhea, urethral tuberculosis or non-specific urethritis. In acute urethritis, the submucosal layer and the tissues surrounding the gland are infiltrated by inflammation. During chronic phase, inflammation gradually absorbs and forms fibrotic changes that cause urethral stricture. Therefore, inflammatory stenosis often occurs in acute urethritis 1 year or several years later. The urethral stricture caused by inflammation is more extensive than that caused by trauma, and the scar tissue is more and the treatment is difficult. Indwelling catheter, foreign body in the urethra, stones, diverticulum can induce urinary tract infection, phimosis secondary to the foreskin penis inflammation caused by urethral stricture, often delayed treatment, inflammation can spread backwards, resulting in long urethral stricture, Regardless of trauma or inflammatory urethral stricture, the proximal urethra of the stenosis expands due to stagnant water, and the infection of the urine causes severe fibrosis, which can aggravate the extent and extent of urethral stricture. The urethral tube is narrow when the urethra is narrow, but a small number of patients can still pass through the catheter or urethral probe. However, due to the compression of the surrounding scar, dysuria is difficult. Some people call it "elastic urethral stricture".

Symptoms of urethral stricture may vary depending on the extent, extent, and course of development. The main symptom is difficulty urinating. It is laborious to urinate at the beginning, the urination time is prolonged, and the urine is bifurcated. Afterwards, the urinary line becomes thinner, and the range becomes shorter or even dripping. When the detrusor contractes and cannot overcome the urethral resistance, residual urine increases or even overflows urinary incontinence or urinary retention. Chronic urethritis is often associated with urethral stricture. At this time, there is often a small amount of purulent discharge outside the urethra. It is often found in the morning, and the urethral orifice is closed by 1, 2 drops of secretions, which is called "morning drop". The proximal urethral dilatation is prone to repeated urinary tract infections, periurethral abscesses, urethral fistulas, prostatitis, and epididymis due to urinary retention. In turn, pelvic ureteral hydrops caused by obstruction and recurrent urinary tract infections eventually lead to renal dysfunction and even uremia.

Urethral stricture can often be accompanied by recurrent bladder, periurethral infection, upper urinary tract infection and reproductive system infection. When accompanied by acute testicular epididymitis, the scrotum is red and swollen, and there is painful pain in the case of acute prostatitis, accompanied by systemic symptoms such as chills, high fever, and elevated white blood cells. The cellulitis around the urethra is characterized by redness and tenderness of the perineum. After the abscess is formed, the urinary fistula can be worn by itself. The urinary fistula is located at the distal end of the external sphincter. When the urination is only urinating, there is urine overflow in the mouth, and the urine in the proximal end continues to overflow. Long-term dysuria can be complicated by inguinal hernia, anorectal prolapse, etc., can also cause upper urinary tract water, and eventually chronic renal failure.

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