Follow the Stream: Imaging of Urinary Diversions

Urinary diversion is a surgical technique to redirect the stream of urine, most often after cystectomy. Cystectomy may be performed both for benign and for malignant conditions. Bladder cancer is the most common indication for cystectomy, and most patients who undergo radical cystectomy and urinary diversion have muscle-invasive or high-risk non-muscle-invasive bladder cancer. There are two major surgical approaches for urinary diversions performed after radical cystectomy: continent and incontinent diversions. For incontinent urinary diversions, a cutaneous ostomy is used for continuous urine drainage (eg, ileal conduit). With a continent diversion procedure, the patient may void through the native urethra or self-catheterize through a surgically created stoma. The goals of imaging after urinary diversion are to assess postoperative anatomy, detect postoperative complications, evaluate for residual or recurrent tumor and metastatic disease, and monitor for upper tract distention and/or deterioration. Multiple imaging modalities and techniques may be used to evaluate urinary diversions, including computed tomographic and magnetic resonance urography, intravenous pyelography, ultrasonography, pouchography, loopography, and nephrostomy studies. Knowledge of the expected postoperative appearance after urinary diversions and potential postoperative complications is crucial because many complications may be clinically silent. Radiologists must be able to recognize the expected postoperative appearance as well as complications to facilitate appropriate diagnosis and treatment of patients after cystectomy and urinary diversion. (©)RSNA, 2016.