Imaging Guidelines for Vesicovaginal Fistula Repair

Rationale for CT Cystography Superiority

The American College of Radiology recommends CT cystography over conventional X-ray cystography for confirming healing after vesicovaginal fistula repair, due to its superior diagnostic accuracy for detecting bladder fistulas and leaks 1, 2
CT cystography has become the primary imaging modality for bladder fistulas and leaks, with the American College of Radiology stating that it has replaced fluoroscopic cystography for evaluation of bladder injuries and fistulous communications 1, 2

CT provides superior anatomic detail and can detect complications that fluoroscopy may miss, including small residual tracts, associated abscesses, or other pelvic pathology 1, 2
The cross-sectional imaging capability of CT allows assessment of surrounding structures and complications beyond what fluoroscopic cystography can demonstrate 1

MRI pelvis with IV contrast provides superior soft tissue resolution and is equally sensitive to CT for evaluating vesicovaginal fistulae, according to ACR guidelines 1, 2
MRI should be considered if there is concern for complex fistula anatomy, multiple tracts, or need to assess for active inflammation in the healing tract, although this is not directly cited, MRI is particularly useful when radiation exposure is a concern in younger patients requiring multiple follow-up studies 1

Conventional X-ray cystography should only be used if CT is unavailable or contraindicated, as it has inferior diagnostic accuracy compared to CT cystography 1, 2
Fluoroscopic cystography is "generally not useful" according to ACR guidelines and has been supplanted by CT at most institutions 1, 2

Do not rely on clinical examination alone to confirm healing, as studies demonstrate imaging is superior to clinical evaluation for detecting residual fistulous tracts 3, 4
Do not use barium-based contrast agents; water-soluble contrast is mandatory for cystography 1

The American College of Radiology recommends CT with intravenous contrast as the preferred initial imaging modality, with a diagnostic sensitivity of 76.5% for fistula detection and 94.1% for defining the etiology 5, 6
Water-soluble contrast should be placed in the bladder to help opacify the fistulous tract during imaging 6
The bladder can be opacified retrograde (CT cystogram) or antegrade with delayed imaging after IV contrast administration 7
Cystography has shown high detection rates (90%) for vesicular fistulae in some studies and should be considered if CT findings are equivocal 6
MRI pelvis with IV contrast provides superior soft tissue resolution for evaluating fistulous tracts and is particularly useful for detecting active inflammation 5
Vaginography may be helpful in certain cases, with reported sensitivity of 79% and positive predictive value of 100% for identification of fistulous tracts 6