膀胱尿道异物

　　一、发病原因

　　1、异物进入膀胱的途径和方式

　　（1）异物经尿道自行或被其他人放入膀胱：经尿道自行或被其他人放入膀胱是膀胱异物最多见的类型。患者为达到性快感作为一种手淫方式将异物放入尿道而后进入膀胱；有的为了达到流产的目的或达到避孕的目的，将异物放入膀胱。精神异常或酒醉后将异物经尿道进入膀胱；极个别人出于恶作剧强行将异物塞入他人尿道而进入膀胱。

　　(2) Iatrogenic bladder foreign bodies: Iatrogenic bladder foreign bodies are due to the introduction or retention of foreign bodies in the bladder during surgery or instrumental examination. During endoscopic examination or surgery, the instruments may break due to poor quality or operation, and remain in the bladder. During endoscopic surgery, the placement of double 'J' tubes for a long time can cause stone formation on the tube wall, making it impossible to remove the tube.

　　(3) Foreign bodies enter the bladder through open wounds: Open bladder injury can bring in foreign bodies such as fabric, buttons, bone fragments, etc., as sequelae of war injuries.

　　(4) Foreign bodies migrate into the bladder from outside the bladder: Patients have a history of firearm injury, pelvic fracture, chronic pelvic osteomyelitis, and open surgery for fixation of femoral neck fracture. Foreign bodies are adherent to the bladder wall due to inflammation, causing erosion and ulceration of the bladder wall, and foreign bodies enter the bladder. The intrauterine device in women also enters the bladder in this way.

　　(5) Foreign bodies enter the bladder from the intestines: Foreign bodies entering the bladder from the intestines are due to intestinal-vesical fistulas. Foreign bodies are often undigested food or parasites, and often cause symptoms of gas in the urine. The cause of fistula is usually tumor or tuberculosis.

　　2. Ways for foreign bodies to enter the urethra

　　(1) Placed through the external orifice of the urethra: This is the most common entry route for urethral and bladder foreign bodies.

　　(2) Excreted through the bladder: some foreign bodies can be excreted from the bladder into the urethra, get stuck, and cannot be excreted.

　　(3) Introduced through surgery or open injury: such as unabsorbed silk thread, cotton balls used for hemostasis, metal mesh支架 inserted during surgery with infection, etc.

　　Second, pathogenesis

　　Bladder and urethral foreign bodies can directly cause mechanical stimulation and injury to the bladder and urethra, infection of the urethra and surrounding tissues, urination disorders, hematuria, urinary extravasation, stones, bladder fistula, or urethral fistula, and other complications. Because the male urethra is longer and has two natural curves, foreign bodies are more likely to remain in the urethra without entering the bladder. The female urethra is short and straight, and foreign bodies are more likely to enter the bladder through the urethra.

　　1. If the foreign bodies enter the bladder due to inflammation and are removed within 1 to 2 days, there are generally no symptoms of urinary tract infection. If the time is longer, continuous mechanical stimulation of the bladder mucosa and the bacteria carried in can cause bladder inflammation. Bladder inflammation is the most common complication of bladder foreign bodies.

　　2. Foreign bodies in the bladder can become the core of stones, with urinary salts gradually precipitating and adhering to the foreign bodies, eventually forming stones. In a case of an elderly patient with bladder stones, an X-ray film showed that there was a coiled metal wire in the stone, and the medical history showed that three years ago, copper wire was inserted into the urethra and not removed. In another patient with a vesicovaginal fistula, the thread ends of the silk suture used to close the fistula were exposed inside the bladder, and stones formed with the silk as the core after half a year.

　　3. Perforated foreign bodies mechanically stimulate the bladder wall, forming ulcers over time and piercing out of the bladder into the peritoneal cavity, perivesical space, rectum, or vagina, often causing vesicovaginal fistula, perineal urethritis, peritonitis, etc. Schwartz (1931) reported a case where a needle used for weaving pierced out of the bladder into the peritoneal cavity, causing peritoneal inflammation.

　　1. Medical history

　　Foreign bodies in the bladder area generally have a clear history of inserting foreign bodies into the urethra, those retained in the urethra are urethral foreign bodies, and those entering the bladder become bladder foreign bodies. Some patients may have a history of masturbation or mental illness; they may also have a history of bladder surgery.

　　2. Clinical symptoms

　　Symptoms vary with the nature, location, duration of retention, and complications of the foreign body. In the early stage, they may manifest as pain and urinary disorders. Patients with injury may have hematuria. Foreign bodies in the bladder can irritate the bladder mucosa, and in cases of concurrent infection, symptoms such as frequent urination, urgency, and dysuria may occur, as well as bladder irritation symptoms. Pyuria may also occur, and in severe cases, complications such as perineal urethritis or perineal abscess may occur, with systemic and local infection symptoms. If the foreign body is located at the bladder neck or urethra and a stone is formed with the foreign body as the core, it may cause difficulty in urination or urinary retention. In cases of large stones, symptoms such as urinary incontinence and upper urinary tract hydronephrosis may occur. Long-term irritation of the foreign body may induce bladder wall cancer, and hematuria may occur. In cases of intestinal urinary fistula caused by penetrating injury, feces, food residues, and gas may be excreted during urination.

　　3. Physical examination

　　Foreign bodies located in the anterior urethra can be seen at the urethral orifice or felt on the body surface, and those located in the posterior urethra can occasionally be felt through the rectum. Through bimanual examination, large foreign bodies in the bladder can be felt (especially in women).

　　Foreign bodies can enter the bladder through the urethra either spontaneously or by others. It is the most common type of bladder foreign body. Patients may insert foreign bodies into the urethra for sexual pleasure as a form of masturbation, and then they enter the bladder; some may insert foreign bodies into the bladder for the purpose of abortion or contraception. Therefore, it should be avoided to insert foreign bodies into the urethra during play or masturbation.

　　Urine examination may show pus cells and red blood cells, and in cases with concurrent infection, the blood leukocyte count increases.

　　1. Imaging examination: Ultrasound examination can show urethra and abnormal hyper-echoic images in the bladder, KUB plain film and IVU can detect X-ray-opaque metals and other foreign bodies in the urinary tract. For those with stones formed with the foreign body as the core due to prolonged stay of the foreign body in the bladder, the shadow of the stone can also be displayed in KUB plain film and IVU. For those suspected of having urinary fistula between the urinary tract and digestive tract, gastrografin enema can show the shadow of the fistula.

　　2. Cystourethroscopy can clearly determine the shape and nature of the foreign body, the injury and extent of the damage caused by the foreign body to the bladder, as well as the stones formed with the foreign body as the core.

　　It is recommended to eat celery, chive, leek, winter melon, hawthorn, dried persimmon, sesame, lotus seeds, and sea cucumber. The patient's diet should be light and easy to digest, with an emphasis on vegetables and fruits, a reasonable diet, and adequate nutrition. In addition, patients should avoid spicy, greasy, and cold foods.

　　1. Ureteral Foreign Bodies Once a ureteral foreign body is diagnosed, efforts should be made to remove it. Common methods include the following:

　　(1) Endoscopic removal of foreign bodies through the urethra: This method can be used to remove small, thread-like foreign bodies.

　　(2) Cystotomy for removal of foreign bodies: If the foreign body is large and difficult to remove endoscopically, a suprapubic cystotomy should be performed to remove the foreign body.

　　(3) Treatment of double 'J' tube stones: Sometimes, a thin layer of hard crust forms on the surface of the double 'J' tube, which cannot be removed by cystoscopy. ESWL technology can be used to strike the tube at the renal pelvis end to dislodge the stones from the tube wall, and the double 'J' tube can be removed by cystoscopy at this time.

　　(4) Failure of urinary catheter balloon: Sometimes, due to the quality of the catheter, the fluid in the balloon cannot be drained, so the catheter cannot be removed. There are two methods for removal: ① Insert the stent wire of the ureteral catheter through the small hole of the balloon channel at the end of the catheter to puncture the balloon and remove the catheter; ② If the above method is ineffective, a puncture aspiration of the catheter balloon can be performed under B-ultrasound guidance in the bladder area to empty the contents, and the catheter can be removed.

　　2. Urethral Foreign Bodies

　　(1) For smooth-surfaced foreign bodies, the far end of the urethra can be tightly held with the hand, and the foreign body can be flushed out by suddenly releasing it while urinating with force. If this is ineffective, a forceps or a clamp can be used to remove it.

　　(2) For foreign bodies that are rough, hooked, or embedded in the urethral wall, appropriate incisions should be made for removal.

　　(3) Removal of foreign bodies under the direct vision of urethroscope: This is particularly suitable for foreign bodies entering the posterior urethra. If the foreign body is too large or not suitable for removal by endoscope, open surgery should be considered.

　　3. For those who form bladder stones due to concurrent factors such as infection, surgical treatment is necessary. Antibiotics should be used to control infection before surgery.

　　4. For those with concurrent urinary tract fistula, the fistula should be excised and the fistula mouth repaired at the same time as the foreign body is removed during surgery.