What is Urethral Stenosis?

Such as urethral stricture, urethral valve, hypertrophy, etc .;

Liu Xigao	(Attending physician)	Department of Urology, Peking University First Hospital
Lin Jian	(Deputy Chief Physician)	Department of Urology, Peking University First Hospital

Urethral stenosis is a common urinary system disease, which is more common in men. Clinically, there are congenital urethral strictures such as congenital urethral stricture, urethral valve, spermatic hypertrophy, and urethral lumen congenital stenosis. Intraluminal infections and injuries are caused, and traumatic urethral strictures are mostly caused by improper management of the initial injury.

Western Medicine Name

Urethral stricture

Affiliated Department

Surgery-urology

Disease site

Urethra

Contagious

Non-contagious

Classification of urethral strictures

Congenital urethral stricture

Such as urethral stricture, urethral valve, hypertrophy, etc .;

Urethral stricture

Medical history should pay attention to whether there is a history of specific or non-specific urinary tract infections, history of gonorrhea tuberculosis, and no history of phimosis and foreskin infection.

Urethral stricture

The most common is due to severe urethral damage, improper initial treatment or delay. The degree, depth, and length of pathological stenosis vary widely. Usually there is only one stenosis. Gonorrhoeic stenosis may be multiple stenosis. The stenosis may be secondary to infection, forming urethral diverticulum, periurethral inflammation, prostate or epididymitis. Because the urinary obstruction cannot be lifted for a long time, it can eventually cause hydronephrosis and uremia due to renal impairment. In the history, pay attention to whether there is a history of pelvic fractures, perineal riding injuries and stab wounds, firearm injuries, or foreign body urethra.

Clinical manifestations of urethral stricture

Symptoms of urethral stricture can vary according to its degree, scope, and development process: 1) difficulty urinating, progressive poor urination, thinned urine flow, sometimes interrupted urination, dripping urination, and even urination; 2) urine retention; 3 ) Urinary incontinence; 4) Long-term dysuria causes pathological changes in the upper urinary tract, hydronephrosis, renal atrophy, and renal insufficiency. 5) Sexual function status: Whether the penis can erect 6) Anal defecation condition, whether there is abnormal urination or defecation.

The main symptom is difficulty urinating. Urination is laborious at first, prolonged urination time, and bifurcation of urine. Later, the urination line gradually becomes thinner, the range becomes shorter and even drips. When detrusor muscles contract and cannot overcome urethral resistance, residual urine increases or even urinary incontinence or retention. Urethral stricture is often accompanied by chronic urethritis. At this time, there is often a small amount of purulent secretions in the outer mouth of the urethra. Most of them are found in the morning, and the urethra is closed by 1, 2 drops of secretions, called "morning drops". Proximal urethral stenosis due to stenosis is prone to repeated urinary tract infections, periurethral abscesses, urethral fistulas, prostatitis, and epididymal hair due to urinary retention and infection. Then the obstruction caused hydronephrosis of the pelvis and ureter, and recurrent urinary tract infections eventually led to renal failure and even uremia.

Diagnosis of urethral stricture

History and physical examination of urethral stricture

1. A detailed description of urinary trauma, infection, urinary catheterization, indwelling ureter, urethral dilatation, and history of surgery.

1) Traumatic urethral stricture: whether there is a history of pelvic fracture, perineal riding injury and stab wound, firearm injury, or foreign body in the urethra.

2) Infectious inflammatory urethral stricture: history of specific or non-specific urethral infection, history of gonorrhea tuberculosis, and history of repeated infection of phimosis and foreskin.

3) Urinary tract stricture caused by urinary catheter indwelling infection

4) Iatrogenic urethral stricture: with or without urethral dilatation, cystoscopy, transurethral bladder tumor or prostatectomy, stone removal with urethral forceps, etc.

5) Congenital urethral stricture: urethral valve, congenital urethral stricture, hypertrophy

Clinical manifestations of urethral stricture

1) Difficulty urinating, progressive poor urination, thin urine flow, sometimes interrupted urination, dripping urination, and even urination.

2) Urinary retention

3) Urinary incontinence

4) Long-term dysuria causes pathological changes in the upper urinary tract, hydronephrosis, renal atrophy, and renal insufficiency.

5) Sexual function status: Whether the penis can erect

6) Anal defecation, urination and defecation

Past history of urethral stricture

Have a history of heart disease, hypertension, diabetes, or lung disease

Physical examination of urethral stricture

(1) Digital rectal examination: It is an important examination to provide important clues in determining the location and extent of urethral stricture and whether it is associated with rectal injury. When the posterior urethral rupture occurs, the prostate moves upwards with a floating sensation; if the prostate is still fixed, it usually indicates that the urethra is not completely broken. However, sometimes pelvic hematomas caused by pelvic fractures often interfere with palpation of smaller prostates, especially in younger male patients, when hematomas are often palpated, and prostate palpation is unclear. In addition, digital rectal examination is an important screening method for rectal injuries. Fingers should be palpated along the rectum wall for one week during the examination to find the injury site; if the finger is stained with blood or bloody urine overflows, it means that the rectum is damaged or that the urethra and rectum may penetrate.

(2) Diagnostic Catheterization: It is still controversial because it can cause partial lacerations to become completely broken, exacerbate bleeding, and easily cause secondary infections of hematomas. However, it is still used clinically at present, because for patients with partial laceration, if a trial insertion is successful, it can be avoided. The following points should be noted in the application of diagnostic catheterization: Use a softer catheter for gentle and slow insertion under strict aseptic conditions; Once the catheterization is successful, the catheter should be fixed and left in place, and should not be pulled out lightly; If the catheterization fails, do not try again and again; If the urethra is completely broken, it should not be used.

Inspection purpose: To determine the degree of stenosis, length, location, and presence of false and fistula tracts.

1) Observe the scrotal perineal skin for inflammation, swelling, and fistula; for trauma and surgical scars, the location and extent of urethral stricture, and the sequelae of other systemic injuries.

2) Whether walking along the urethra (anterior urethra) can touch the hard rope, understand the scar, stenosis and length, sometimes the patient himself can clearly indicate the obstructed urination; check the perineum for the presence of fistula; digital rectal examination Post-urethral conditions, including anal sphincter tone, bulbocavernosus reflex, and whether the perineal sensation is normal.

3) Metal urethral probe or induction probe examination: can determine the location and degree of urethral stricture. Use the metal probe principle of 16 ~ 18F blunt tip to avoid false track.

Assistant examination of urethral stricture

Routine hematuria, liver and kidney function, electrolytes. ECG, chest X-ray, urology B-ultrasound, urinary bladder angiography, KUB + IVU, endoscopy.

1) KUB + IVU: can show pelvic fractures; show whether there is obstruction of the upper urinary tract; can carry out excretory cystourethrography at the same time.

2) B-ultrasound: observe the presence of upper urinary tract hydrops and bladder for residual urine. Transrectal B-ultrasound can show the posterior urethral stricture, length and surrounding scars.

3) Urinary bladder angiography: There are two types of urethral strictures: length, and degree:

(1) Excretory cystourethrography: often performed at the same time as intravenous urography.

(2) Retrograde bladder urethral angiography: For severe urethral stricture or complete obstruction of the urethra, simultaneous urethral and transurethral fistula injection can be used to show the narrowed section.

4) Endoscopy: urethrocystoscopy or ureteroscopy to determine the degree and length of stenosis. Mild stenosis can be performed directly under urethral dilatation. For lesions where the length of the stenosed segment cannot be determined, a hard or soft microscope can be examined through the bladder fistula at the same time, and the length of the stenosis and the misalignment of the stump can be understood by taking pictures or fluoroscopy.

Bacterial culture plus drug sensitivity: urine bacterial culture plus drug sensitivity test for patients with urethral stricture

Diagnosis of urethral stricture

Comprehensive diagnosis of urethral stricture

The diagnosis of urethral stricture should be based on medical history, signs, urethral device examination and urethral cystography. The application of urethral instruments can not only confirm stenosis, but also determine the location, number, degree and type of stenosis. Commonly used instruments are catheters, filament probes, urethral probes, and the like. The exploration of the urethral device must be performed under strictly sterile and good anesthesia. If the patient has performed a suprapubic cystostomy, a urethral probe can be placed simultaneously from the inner urethra through the bladder incision. Lateral X-rays can estimate the length and location of urethral strictures. If the urethral probe can pass through the narrow section, a thicker urethral probe can be used to expand the urethra, which is also an effective treatment. Generally it is advisable to start with F20 first. If it fails, use a thinner probe. However, when a thin urethral probe is used for exploration, although a finger can be used to guide the rectum, the danger of penetrating the wall of the urethra or forming a false tract is still prone to occur. Do not use violence. A wire-like probe can be used as a guide to insert the probe into the urethra.

Treatment of urethral stricture

Urethral stricture treatment principles

1. Actively treat urinary tract and surrounding infections;

2. To restore the urethral urination function, restore the anatomical continuity and integrity of the urethra;

3. Avoid new complications during treatment;

4. Bladder ostomy with chronic renal insufficiency;

5. Colostomy first with urethral rectal fistula;

Non-surgical treatment of urethral stricture

Non-surgical treatment mainly depends on urethral dilatation. Even after surgery, cases should be regularly dilated to prevent re-stenosis. Dilatation of the urethra should not be performed when the urethra has acute inflammation, and should be performed under good anesthesia and strictly sterile conditions. Expansion avoids violence. If necessary, guide with one finger in the rectum to prevent penetration into the prosthesis and even the rectum. Expansion must gradually increase from the small rod to the larger rod in order to avoid haste. Excessive expansion can easily lead to lacerations of the urethral tube wall, followed by scar formation and increased stenosis. It is advisable for men to expand to F24. After each urethral dilatation, the urethra is congested and edema. It only subsides after about 2 to 3 days, so it is not suitable for continuous expansion within 4 days. The secondary interval usually starts around one week and gradually extends.

Transurethral injection of urethral perfusion can prevent urethral strictures from recurring. Plays the effect of soft expansion. Physiotherapy methods such as audio frequency and iodine ion penetration can accelerate scar softening and consolidate the effect of expansion.

Urethral stricture surgery

(1) Treatment of posterior urethral stricture: The treatment of urethral stricture after urethral injury is preferably 3 to 6 months. According to the degree of injury, the following surgical methods can be used:

1) Intraurethral incision (optional): Use a urethral scalpel (cold knife) or laser to cut scars in the stenosed area and indwell the urethral catheter after expanding the inner diameter of the urethra. It is suitable for patients with narrow stenosis <1cm and less severe scar. If the results of the second incision are not good, other treatment methods should be used.

2) Urethral anastomosis (recommended): take an incision in the perineum, remove the stenosed part and scar, and end-to-end anastomosis of the two sections of the urethra. Separation of the corpus cavernosum septum, removal of the lower edge of the pubic bone, or removal of part of the pubic bone can be used to narrow the posterior urethral stricture for urethral anastomosis. During the operation, the scar should be removed as much as possible and the two ends of the urethra should be tension-free and sutured. The suprapubic bladder fistula is very useful for draining urine and finding the proximal urethra during surgery.

3) Urethral pull-in (optional): It is suitable for patients who cannot perform urethral anastomosis. After removing the narrow urethra, the distal urethra is freed, so that it is dragged moderately through the proximal stenosis, and fixed or pulled with a puller It is fixed to the abdominal wall by the bladder. The disadvantage is that it can cause shortening of the penis and inferior curvature of the penis during erection.

4) Urethral replacement angioplasty (optional): Long urethral stricture or atresia. Pedicled skin flaps and free grafts were used to repair the defective urethra.

. Pedicled skin flap: common penis and perineal skin. Skin flaps need a good blood supply, and hair, stones, and diverticulum formation are complications. The incidence of long-term urethral restenosis is still high.

. Free graft: A variety of autologous mucosa, skin, and tissue engineering materials (acellular matrix) are suitable for urethroplasty reconstruction of long narrow sections.

(2) Treatment of anterior urethral stricture: The treatment time for urethral stricture is 3 months after injury.

Short segments of the anterior urethral stricture (<1cm) involving the urethral cavernosal body, especially the urethral stricture located in the bulb, can be treated with endoscopic transurethral incision or urethral dilation (recommended). Patients with dense anterior urethral strictures involving deep corpus cavernosum or ineffective transurethral incision or urethral dilatation need to be treated with open urethroplasty (recommended). Because patients who have failed endoscopic transurethral incision or urethral dilatation treatment repeatedly taking these two treatments are very ineffective and have poor medical economic benefits, repeated endoscopic incision may also make patients eventually need to implement more Complex urethroplasty.

For urethral strictures with a ball less than 2 cm, scar resection and anastomosis is a more appropriate treatment (recommended), and the success rate of this treatment can be as high as 95%. For the penile urethra and long bulbous urethral stenosis ( 2cm), simple end-to-end anastomosis is not recommended, because this will cause patients with erections and pain, and it is recommended to use transfer flaps or Alternative urethroplasty for free grafts (recommended). Intraurethral stents are not recommended for patients with traumatic urethral strictures [88] (not recommended).

Patients with urethral stricture who have failed non-surgical treatment can choose appropriate surgery. There are many surgical treatment methods. How to choose depends on the experience of the doctor, the narrowness of the patient and the medical conditions.

1. External urethral incision is suitable for cases with narrow urethral orifice. More common in patients with foreskin balanitis, partial penile amputation or repair of hypospadias, can be longitudinally cut on the ventral side of the outer urethra to form a mild hypospadias, both sides of the incision The urethral mucosa is sutured to the skin of the head of the penis to stop bleeding.

2. Intraurethral incision, such as urethral stricture, has a very short length, or even a membranous stenosis. You can use a special cold knife to open the stenotic ring under the urethoscope. The incision can be performed with the insertion of a thin ureteral catheter as a guide. If necessary, use an electric knife to remove excess scar tissue. If the narrow posterior urethra is completely occluded, but the length is not long, you can cut the bladder, use one finger to guide inside the bladder, and use a resection microscope or a urethral probe to cut through. A resection microscope was then placed to remove the scar to form a channel. Then leave the catheter in place for a long time (20 days or more) until it heals. It has also been suggested that several thin silicone tubes are left in the urethra for 3 months after surgery. When the patient urinates, the urine is released from the gap between the silicone tubes, and at the same time, it plays a role of dilatation and obtains good results. If multiple urethral strictures can be placed in the Otis, an incision is made. The depth of the cut is controllable.

3 In cases where urethral stricture resection and anastomosis cannot be performed as an incision, a suitable incision should be selected. Under good exposure, the narrow urethra and the surrounding scar tissue are removed, and hemostasis is strictly stopped. Absorbable sutures are used under tensionless conditions. Line for valgus suture at both ends of the urethra. The wound should be completely drained, and the catheter is retained for about 2 to 3 weeks after surgery. Retaining the urinary catheter must use a less stimulating silicone urethral catheter. For posterior urethral strictures, an upper abdominal pubic incision can be selected. If necessary, part of the pubic symphysis can be removed to achieve good exposure. The perineal arc or straight incision can be used in the bulbous urethra. During the operation, the surrounding normal tissue should be minimized to avoid more scars and impotence after the operation. In order to reduce the anastomotic tension, the distal urethra can be free, even directly to the coronary sulcus. But the proximal urethra should not be too long. Posterior urethral stricture resection and anastomosis can be performed with a long straight needle in the transabdominal perineal wound, or the distal urethral stump can be fixed on the urethral catheter with a gut and dragged into the bladder. The urinary catheter is fixed as a stent to achieve the purpose of involution.

4 Narrow urethrotomy is suitable for penile urethral stricture or long urethral stenosis which is difficult to repair in one stage. Incision of the narrow urethra or resection of the narrow urethra and another distal and proximal urethral ostomy are performed to form a hypospadias. After 3 months, repair was performed according to hypospadias. A urethral stricture of the penile segment, such as a one-stage resection and anastomosis, can often result in a urethral skin fistula. Difficult to repair posterior urethral stenosis can also be perforated and perforated or scrotal skin flap pulled into the channel and sutured to the bladder neck to form a perineal hypospadias, which will be repaired later.

5. The urethral defect of urethroplasty can use the bladder mucosa and pedicled bladder flap. Pedicled flaps and / or mid-thickness skin flaps for repair.

6. Urinary diversion surgery Generally, urethral stricture surgery requires simultaneous cystostomy to drain urine to make the operation successful. Patients with failed surgery can maintain a bladder stoma for reoperation or as a permanent treatment.

Urethral stricture surgery is a more difficult operation. It must be fully prepared before surgery, the surgical plan must be accurately designed, and it must be regularly expanded and guarded to achieve good results. Recurrence of stenosis, urinary fistula, thinness, and urinary incontinence are more common complications. ^[1-5]

Postoperative management of urethral stricture

The urinary catheter was left for 1 to 2 weeks after simple endomyotomy. After various other surgical procedures, the urinary catheter is usually left for 3 to 4 weeks. The time to remove the bladder fistula depends on the urination situation. Encourage patients to drink plenty of water and apply antibiotics appropriately.