Role of Contrast-Enhanced Computed Tomography in the Diagnosis and Conservative Management of Rectovesical Fistula Following Robot-Assisted Radical Prostatectomy

Background
The aim of this report is to emphasize the pivotal role of multimodal imaging, particularly contrast-enhanced computed tomography (CT), in the early detection and precise anatomical characterization of rectovesical fistula (RVF), a rare yet severe complication of robot-assisted radical prostatectomy (RARP). Accurate delineation of the fistulous tract enables tailored therapeutic strategies, favoring conservative approaches when feasible and improving clinical outcomes by minimizing morbidity.
Methodology
We describe the case of a 68-year-old man who underwent RARP for prostatic adenocarcinoma (ISUP grade group 3, pT2cN0Mx). Six weeks postoperatively, he developed pneumaturia, fecaluria, and recurrent urinary tract infections. Initial evaluation included clinical assessment and laboratory tests. Contrast-enhanced multidetector CT of the abdomen and pelvis was performed with intravenous iodinated contrast in arterial and portal venous phases. Flexible cystoscopy was subsequently carried out for endoscopic confirmation.
Result
Contrast-enhanced CT demonstrated extravasation of intravenous contrast from the bladder neck region into the mid-rectum, confirming a fistulous communication between the posterior bladder wall and anterior rectal wall. The fistulous tract appeared irregularly enhancing with features suggestive of chronic inflammation, without associated perilesional abscesses, fluid collections, or fascial breach. No extrapelvic infiltration or other complications were identified. Flexible cystoscopy revealed a small posterior fistulous orifice at the bladder base. Conservative management was instituted, consisting of prolonged indwelling urinary catheterization, broad-spectrum antibiotics, and exclusive enteral nutrition. Follow-up CT at eight weeks confirmed complete spontaneous closure of the fistula, with resolution of symptoms and no evidence of residual tract or recurrence.
Conclusion
Rectovesical fistula following RARP has a reported incidence of 0.3–1% and represents a challenging complication. Contrast-enhanced CT serves as the first-line imaging modality of choice due to its high sensitivity for detecting contrast extravasation, delineating tract anatomy, and excluding associated complications such as abscesses or malignancy recurrence. When integrated with endoscopic evaluation, this approach supports conservative management in approximately 70% of selected cases, achieving spontaneous closure and avoiding the risks associated with surgical reintervention. Early and accurate imaging-guided diagnosis is essential for optimizing patient outcomes and reducing long-term sequelae.