Urinary Tract Fistula

Table 35.1. Principles of treatment and surgical repair of a

approximately 0.1–0.2%.8,9 The primary risk

urinary tract fistula

factor for the development of VVF following

nutritional optimization

hysterectomy

appears

to

be intraoperative

injury. Iatrogenic cystotomy, tissue necrosis

Elimination of infection

from cauterization injury, or suture placement

Evaluation for malignancy

through both the bladder and vaginal wall can

predispose to postoperative fistula formation.

adequate exposure of the fistula tract

Tissue ischemia and necrosis lead to fibrosis and

debridement of devitalized or ischemic tissue

inflammation between the bladder and vagina,

careful dissection to maintain separation of involved

eventually allowing formation of an epithelial-

ized tract. This most commonly occurs at the

organ cavities and hemostasis

apex of the vagina at the level of the vaginal

removal of foreign bodies or synthetics

cuff.10 Preoperative risk factors include prior

repair with well-vascularized healthy tissue flaps

cesarean section or uterine surgery, endometri-

osis, infection, diabetes, arteriosclerosis, pelvic

Multiple layer closure with nonoverlapping tension-free

inflammatory disease, and prior pelvic radia-

suture lines

tion.11 Additionally, abdominal hysterectomy is

removal of distal obstruction

three times more likely to

result in bladder

injury compared to vaginal hysterectomy.

Maintain adequate urinary tract drainage

In the industrialized world, radiation is also a

awareness of medicolegal implications

significant cause of complicated urinary tract

fistula. The incidence of radiation-induced fis-

leakage. Descriptions of vesicovaginal fistulas

tula is dependent on the type, dose, and location

of radiation, as well as the specific malignancy

have been well documented since ancient times,

undergoing treatment. Urinary fistula rates of

although early attempts at repair met with little

1.6% have been reported following radiation

success. In 1852, Sims published his method for

treatment for cervical carcinoma.12 VVF from

the surgical treatment of VVF using a transvagi-

radiation may occur as long as several decades

nal approach, followed by Trendelenburg in

following treatment.13 Biopsy of the fistula tract

1888, who successfully performed the transab-

should be strongly considered prior to any

dominal VVF repair.2,3

definitive therapy. Malignancy-induced VVFs

can occur with locally advanced cervical, vagi-

Etiology and Risk Factors

nal, and endometrial carcinomas and account

for approximately 3% of fistulas.14

The etiology and prevalence of VVF differ in

In the developing, nonindustrialized world,

various parts of the world. In the industrialized

VVF most commonly results from complica-

world, the most common cause of VVF is iatro-

tions of childbirth. The incidence of obstetric

genic injury during gynecologic, urologic, or

fistula in developing countries is approximately

other pelvic surgery, accounting for greater than

0.3–0.4% of deliveries, or between 1 and 4 per

75% of cases.2,4,5 Hysterectomy is the most com-

1,000 vaginal deliveries.15,16 Routine prenatal

mon procedure associated with lower urinary

and perinatal obstetrical care is limited, as is

tract injury, with most of the remainder a result

access to general healthcare. Additionally, pelvic

of general surgical pelvic procedures, urogyne-

size may be small due to poor nutritional status

cological procedures such as anterior colpor-

and/or an early age of marriage and concep-

rhaphy,cystocele repair,or incontinence surgery,

tion.17 Prolonged obstructed labor due to

or other urologic procedures.6 In a study of 207

cephalopelvic disproportion can cause pressure

VVF repairs by Eilber et al., the cause was

necrosis of the anterior vaginal wall, bladder,

reported as 83% from abdominal hysterectomy,

bladder neck, and proximal urethra. The

8% from vaginal hysterectomy, 4% from radia-

“obstructed labor injury complex” which occurs

tion, and miscellaneous in 5%.7

in such individuals includes variable degrees of

The overall rate for iatrogenic bladder injury

urethral loss, stress incontinence, renal failure,

at the time of hysterectomy is between 0.5%

vesicovaginal fistula, rectovaginal fistula, rectal

and 1.0%, while the incidence of fistula is

atresia, anal

sphincter

incompetence, vaginal