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Vesicovaginal Fistulæ

Causes

• Obstetric complications: most common worldwide (0.09-0.66 per 1000 pregnancies)
• Iatrogenic: more common in countries with better medical resources, caused by injury at time of pelvic surgery
• Hysterectomy: most common cause of iatrogenic fistula (60-75%), prevalence 0.1-4%, more common with abdominal approach
• Obstetric fistulas more likely to be larger and distally located, involving bladder neck and proximal urethra
• Ketamine abuse has been shown to cause bladder changes and fistula formation

VVF Prevention Principles During Pelvic Surgery

• Immediate detection of bladder injuries
• Watertight bladder closure
• Extravesical drain placement
• Avoid vaginal incisions
• Maintain prolonged bladder drainage

Diagnosis

• Most common symptom is persistent urinary drainage via vagina
• Leakage may be positional if fistual is small
• Pain is uncommon unless severe skin irritation present or history XRT
• Anterior wall is most common location, consider presence of inflammation/infection (may delay repair)
• Consider instilling methylene blue into bladder and looking for staining on tampon, ambulation may increase sensitivity of test
• Double dye test: PO pyridium + intravesical methylene blue, detects ureterovaginal (orange) vs vesicovaginal (blue) fistulas
• Perform cystoscopy, consider biopsy if history of malignancy (may be recurrence)
• CT/MR may show delayed contrast drainage into bladder, may be beneficial to assess for ureterovaginal fistula (CTU)
• VCUG/cystogram can be performed, but needs to show voiding or postvoid images
• Use fistula classification (see Goh image) to assess severity

Treatment

• Consider foley + anticholinergics for 2-6 weeks for fistulæ < 1cm
• Consider electrocoagulation for small (< 3-5mm) fistulæ
• Either time repair for 2-3 weeks after diagnosis, or 2-3 months if outside initial window
• Abdominal vs vaginal approach is mainly affected by surgeon preference
• Vaginal approach may cause vaginal shortening, affecting sexual activity
• Leave catheter for 2-4 weeks, consider cystogram prior to removal
• 85% success rate for primary repairs
• Complications: bleeding, compromised flap blood supply, ureteral injury, vaginal shortening/stenosis, fistula recurrence
• Urinary diversion: best if active malignancy, severe XRT damage, or large tissue loss
• If patient is high surgical risk, consider nephrostomy tubes + ureteral occlusion
• Ureterosigmoidostomy: last resort if unable to perform diversion or other repairs

Flaps

• Transvaginal approach: labial fat pad (Martius) or peritoneal flap
• Transabdominal approach: peritoneal or omental flap
• Martius flap: fibrofatty labial tissue best used if fistula involves trigone or bladder neck, does not usually reach vaginal apex fistulæ
• Peritoneal flap: better for high fistulæ, mobilize from anterior culdesac, repair any peritoneotomies

Ureterovaginal Fistulæ

Presentation

• Commonly presents 1-4 weeks after surgery with constant urinary leakage
• Patients will have normal voiding patterns due to filling from normal side, whereas VVF will report constant leakage only
• Preoperative stenting: no change in injury rates (1.2% vs 1.1%)
• Ascitic or extravasated fluid will have elevated creatinine level
• Diagnose with CTU or retrograde pyelogram

Treatment

If ureter is patent, attempt stent placement (~50% closure rate)

If unable to stent, place nephrostomy tube and perform delayed repair (4-6 weeks) with reimplantation

Reimplant tips: preserve adventitial layer, tunneling not required

Success rate: 90% after formal repair

Ureterouterine or ureterofallopian fistulæ are rare

Other Female Fistulæ to Consider

Vesicouterine Fistulæ

• Usually caused by simultaneous bladder and uterine injury, C-section is most common cause
• Cervix may act as a sphincter and may prevent expected constant leakage
• Youssef syndrome: menouria, cyclic hematuria with amenorrhea, infertility, and urinary continence in a patient with prior C-section
• Diagnosis: cystogram or hysterosalpingogram
• Consider prolonged catheterization, menopause induction, or formal surgical repair with omental flap
• Uterine-sparing surgery can be performed to preserve future fertility, otherwise perform hysterectomy

Urethrovaginal Fistulæ

• Occurs with prolonged labor, SUI treatments, prolonged catheterization (urethral erosion), or after genital reconstruction
• Distal fistulæ may present as split stream or vaginal voiding
• Diagnose with exam, cystoscopy, and VCUG
• Vaginal repair most commonly used, success rates 70-90% after primary and 92-97% after secondary repair
• Can consider SUI repair at time of fistula repair, with use of Martius flap

Colovesical Fistulæ

Causes/Presentation

• Most commonly seen with diverticulitis (20% patients), Crohn disease (2-6% patients), and colonic malignancy
• LUTS more common presenting symptom than GI - pneumaturia (52-77%), fecaluria (36-51%), UTI (44-45%), hematuria (5-22%), orchitis (10%), urine per rectum (5%)
• Gouverneur syndrome: suprapubic pain, frequency, dysuria, tenesmus
• Pyeloenteric fistulæ: seen with inflammatory disease (XGP kidney) or post-surgical (PCNL)

Diagnosis

• Cystoscopy: provides definitive diagnosis in 35-46%
• CT triad: bladder wall thickening adjacent to thickened colon, air in bladder, and presence of diverticula
• Contrast studies (enema/cystography): surprisingly, less useful for identifying fistulas
• Charcoal study: PO intake of charcoal will demonstrate charcoal flakes in the urine if fistulæ present

Treatment

• If nontoxic, minimally symptomatic, and nonmalignant cause -> TPN, bowel rest, and antibiotics
• Non-surgical approach preferred for Crohn disease due to high risk for recurrence
• Staged repair (ostomy + reversal): indicated for unprepared bowel, gross contamination, or abscess
• Three staged treatment for complex fistulas: proximal defunctioning and distal drainage, TPN + nutritional support, then joint reconstructive surgery

Rectourethral fistulæ

Causes/Presentation

• Seen with prostate surgery (< 1-2%) or XRT (0.4% brachytherapy), malignancy, infection/abscess
• May present with fecaluria, hematuria, UTI, sepsis
• DRE may detect fistula on rectal wall
• Cystoscopy/sigmoidoscopy can confirm diagnosis and may provide biopsy (assess for malignancy)
• VCUG/RUG confirm diagnosis and provide length/location for surgical planning
• Consider upper tract imaging to exclude ureteral injury

Treatment

• Some may heal with catheterization, bowel rest, and TPN - some may require temporary bowel diversion
• One-stage repair: small fistulæ not associated with infection/abscess
• Staged repair: large fistulæ, history XRT, infection, immunocompromise, or inadequate bowel prep
• Success rates 88%, with permanent fecal diversion (11%) and urinary diversion (8%)
• York-Mason: transrectal, transsphincteric repair

Vascular-Related Fistulæ

Renovascular/Pyelovascular Fistulæ

• Commonly seen with PCNL due to intrarenal vascular puncture, also seen with erosion of chronic nephrostomy tube into vasculature
• PCNL risks: transfusion (11%) and surgical/angiographic intervention (1%)
• Presentation: active bleeding with nephrostomy tube removal, sudden hematuria or flank pain (usually 2 weeks after PCNL)
• Nephrostomy tube removal: replace tube or place foley and inflate to tamponade
• IR embolization for unstable patients, nephrectomy rarely indicated

Ureterovascular Fistulæ

• Risk factors: prior XRT, pelvic cancer surgery, pelvic vascular surgery, chronic ureteral stents, less commonly AVM, kidney transplant, pseudoaneurysm
• Presentation: almost always with hematuria
• Diagnosis: angiography only has 62% sensitivity (due to intermittent bleeding or transient thrombus formation), have high degree of suspicion, consider "provocative" angiography (manipulate suspected site)
• Treatment: endoscopic vascular stenting (if stable) or open repair (if unstable)
• High mortality rate (7-23%)

General fistulæ management

General tips

• Consider predisposing/complicating factors: radiation, prior surgery
• Remove distal obstructions, and consider proximal diversion
• Optimize nutritional status, may help fistulas spontaneously close

General postop tips

• Maintain urinary drainage (foley, stent) to maximize healing
• Consider exam or imaging study prior to removing tubes to confirm fistulæ closure
• Consider vaginal estrogen to maximize epithelial healing