A urinary fistula is a pathological condition in which part or all of the urine is discharged through an abnormal channel in the urinary tract or after flowing through other organs and then out of the body. Depending on the site of occurrence, it can be divided into ureteral fistula, bladder fistula and urethral fistula. According to the site where the fistula leads, it can be divided into external fistula, which means that urine is discharged directly through the fistula, and internal fistula, which means that urine is first discharged into other organs through the fistula and then discharged out of the body. The former is the direct discharge of urine through the fistula and the latter is the discharge of urine into other organs before discharge.
I. Ureteral fistula
Common ureteral fistulas include ureterovaginal fistula and ureterocutaneous fistula.
[Diagnostic criteria]
1, Ureteral fistula is characterized by persistent vaginal or cutaneous fistula leakage, but the patient can still urinate normally.
2. Intravenous urography and retrograde ureteropelvography can help in the diagnosis.
[Treatment]
The treatment of urinary fistula is to remove the fistula and restore the normal passage of the urinary tract.
(i) Surgical approach
The aim of treatment for ureteral fistula is to remove the fistula and restore the normal channel of the ureter.
1.Ureteral stent tube for drainage: Ureteral stent tube not only plays the role of supporting drainage and preventing urinary extravasation for the repaired ureter, but also applies to damaged ureteral fistula with partial defect of the tube wall.
2, proximal ureteral fistula repair: if the ureteral fistula is close to the bladder, then use the ureteral bladder anti-reflux anastomosis; if the normal ureter at the distal end of the fistula is of sufficient length, then directly anastomose the proximal end of the loosened ureter with it, around which the large omentum can be wrapped, if the distal ureter is not normal and difficult to use, then feasible bladder lumbar muscle suspension or bladder wall flap ureteroplasty to solve.
3, repair of middle ureteral fistula: if the defect is not long, simple spatulate overlapping anastomosis is used; if the defect is too long and the anastomosis is under high tension, the tipped large omental wrapping is added; other methods include autologous kidney transplantation and end-lateral anastomosis between the proximal ureter and the contralateral ureter.
(B) Complications of surgery
1.Leakage of urine
2. Re-formation of ureteral fistula
3.Ureteral stenosis
4. hydronephrosis
II. Bladder fistula
Bladder fistula is an abnormal passage between the bladder and other organs or parts. All or part of the urine is discharged out of the body through this channel, or through other organs in the body and then out of the body. These include vesicovaginal fistula, vesicouterine fistula, vesicorectal fistula, and vesicocutaneous fistula, with vesicovaginal fistula being the most common. The causes include prolonged labor, fetal compression of the bladder neck, triangle, and vagina, resulting in ischemic necrosis of the tissue and fistula formation; injury to the bladder and vagina during uterine surgery; and perforation of the vagina by malignant bladder tumors. In addition, such as transurethral electrodesiccation of the bladder neck, bladder stones, and bladder tuberculosis can cause vesicovaginal fistula.
[Diagnostic criteria]
(A) There is a cause of urinary fistula, such as obstructed labor, pelvic surgery, or history of pelvic radiation therapy.
(ii) Clinical manifestations: constant transvaginal flow of urine, eczema-like changes in the vulva and inner femur, vulvar pruritus and burning pain, etc.
(iii) Ancillary examinations
1. Vaginal examination can often determine the location of the fistula. Dry gauze is inserted into the vagina and the bladder is injected with methylene blue solution; blue staining of the gauze indicates the presence of a vesicovaginal fistula.
2, Cystoscopy can clarify the location and size of the fistula.
3, Cystogram: contrast is found to enter the vagina.
4, Vesicovaginal fistula of unknown origin can be diagnosed clearly by taking a biopsy of the edge of the fistula hole via vaginal or cystoscopy.
(iv) Differential diagnosis
1, ureterovaginal fistula: history of trauma or surgery. The injured ureter is constantly flowing out of the vagina after the fistula hole is formed and needs to be distinguished from vesicovaginal fistula. However, the vaginal gauze does not stain when the ureterovaginal fistula is injected with mebrane fluid in the bladder. On cystoscopy, the ureteral orifice on the injured side does not spray urine, and the cannula is obstructed and cannot be inserted.
2, ureteral orifice ectopic: If the ureteral ectopic opening is in the vagina, there can be persistent vaginal leakage, and the two need to be distinguished. Ureteral ectopic opening is a congenital developmental abnormality with no history of trauma or surgery. Vaginal examination reveals an ectopic ureteral opening, which can be as small as a pinpoint, with smooth mucosa around the opening and a drip-like drip of urine. Excretory urography, mostly with bilateral renal pelvis and double ureteral malformation on the affected side or both sides, and ultrasound examination may reveal double renal pelvis.
[Treatment]
The treatment of urinary fistula is to remove the fistula and restore the normal passage of the urinary tract.
(i) Surgical procedure
1. Vesicovaginal fistula
(1) Non-surgical treatment: For small vesicovaginal fistulas, a urinary catheter can be left in place for two weeks and antibiotics can be given to prevent infection, and the fistula may heal spontaneously.
(2) Surgical treatment: If the fistula is large, it must be repaired surgically.
The timing of surgery: 5-6 months after delivery or 2-3 months after surgery.
The surgical route: depends on the location of the fistula. If the location is low, the transvaginal route is preferred; if the location is high, the transvesical route is preferred; if the fistula is huge, the combined transabdominal perineal route can be used.
The scar tissue around the fistula must be removed, and it is best to decompose three layers of tissue, namely the bladder wall, the vaginal mucosa, and the tissue between the two; the absorbable sutures are interrupted and tension-free; and the suture incisions should be staggered in each layer. If bladder contracture or tumor with vesicovaginal fistula cannot be repaired, urinary diversion can be considered.
2.Vesicovaginal fistula
(1) Preoperative preparation of the intestine according to the routine of intestinal surgery.
(2) Remove the diseased intestine and fistula, restore intestinal continuity and repair the bladder. If the condition is severe, the surgery can be staged.
(3) If it is caused by intestinal tuberculosis, anti-tuberculosis treatment should be given before surgery, and if it is caused by advanced malignancy, permanent colostomy can be considered.
(3) Vesico-rectal fistula: The surgical principles are the same as those for vesico-enteric fistula repair.
(ii) Surgical complications
1, failure of repair and re-formation of vesicovaginal fistula.
2, vesicovaginal fistula surgery can have complications such as intestinal anastomotic fistula, stricture and intestinal obstruction
3, vaginal stricture.
4, ureteral obstruction.
III. Urethral fistula
Urethral fistula is a fistula between the urethra and the body surface directly or through other systemic organs that are abnormally connected. Depending on the pathogenesis urethral fistula can be divided into two categories: congenital and acquired, and the latter can be divided into two categories: traumatic and pathological. Urethral fistulas are divided into external and internal fistulas depending on the urinary flow. External fistulas are those in which urine is partially or completely discharged through abnormal channels in the urethra during urination, such as those in the penis, scrotum, and perineum. Internal fistulas are fistulas in which urine is first drained through the urethra into other organs and then out of the body, such as urethrovaginal fistulas and urethrorectal fistulas. Common urethral fistulas include urethrovaginal fistula, urethrorectal fistula, and urethral cutaneous fistula.
[Diagnostic criteria].
(A) Medical history: history of trauma, surgery or obstructed labor, urethral tuberculosis, urethral cancer, cervical cancer and local long-term radiotherapy.
(b) Clinical manifestations: urethral cutaneous fistula can be seen as urine flowing out of the body from the fistula hole, and the diagnosis is not difficult. The urethro-rectal fistula, with anal urination, is often mixed with feces and gas in the urine discharged from the urethra. In urethrovaginal fistula, if the fistula is large and located at the proximal end of the urethra, there may be continuous leakage of urine from the obstructive tract without spontaneous urination, and if the fistula is small and located at the distal end of the urethra, urine may be discharged from both the urethra and the vagina only during urination.
(iii) Auxiliary examinations
1. urethrorectal fistula: diagnosis can be confirmed by rectal palpation, urography, proctoscopy or urethrocystoscopy.
2. urethrovaginal fistula: vaginal examination, urethral probe examination, melanoma test and colposcopy or urethroscopy can help in diagnosis.
(d) Voiding cystourethrography, X-ray plain radiographs of the pelvic area, and intravenous urography can also help in the diagnosis.
(E) Differential diagnosis
(1) Ureteral orifice ectopic: congenital developmental anomaly, mostly with double renal pelvis and double ureteral malformation. In the normal urethral orifice
In addition to the normal urethral orifice, persistent drip-like fistula can be seen in the urethra, perineum, uterus and vagina. In intravenous pyelogram, duplicate renal pelvis and duplicate ureter can be seen and are often accompanied by hydronephrosis.
2. Vesicovaginal fistula: persistent dripping of urine from the vagina. The gauze basket is stained in the vagina after injection of Mebane solution into the bladder. The intravesical fistula opening is visible through cystoscopy.
[Treatment]
The treatment of urinary fistula is to remove the fistula and restore normal access to the urinary tract.
(i) Surgical approach
The treatment of urethral fistula should be decided according to the cause of occurrence, the location and size of the fistula.
1, trauma-induced urethral fistula, should be near early urinary flow diversion. If the inflammation is obvious, you must wait for the inflammation to subside before you can operate.
2, the distal urethra of the fistula hole has a stricture, the stricture must be lifted first.
3, more thorough excision of the scar around the fistula, layered sutures, suture incisions do not overlap, cystostomy drainage of urine.
4. For pathological urethral fistula, the primary disease must be treated first and then the urethral fistula must be repaired, and if necessary, the urinary flow must be rerouted.
(ii) Surgical complications
1, failure of repair and re-formation of urethral fistula.
2, urethral stricture.
3.If urethral diversion is performed, the corresponding complications can occur.