A Case of Spontaneous Urinary Extravasation Suspected to be Chronic Urinary Retention

Abstract

Spontaneous urinary extravasation is considered to a decompression mechanism in which a microscopic rupture occurs in the mucosa of the renal fornix due to a sudden increase in renal pelvic pressure, leading to urine leakage into the retroperitoneal space. It is considered to be often caused by a temporary and acute rise in renal pelvic pressure. We report a case of spontaneous urinary extravasation in an elderly bedridden woman, presumably triggered by chronic urinary retention. The patient was 71-year-old woman receiving home medical care for Alzheimer’s disease. She had been receiving intravenous therapy for several days due to poor oral intake. Because of fever and vomiting, she was suspected to have intestinal obstruction and was transported to our emergency department. A non-enhanced CT scan revealed moderate urine collection in the bilateral retroperitoneal spaces and severely dilated bladder within the pelvic cavity. She was admitted to the hospital with a diagnosis of pyelonephritis, retroperitoneal urinary extravasation and urinary retention. About 1,200 mL of urine was drained by urethral catheterization. Subsequently she was referred to the urology department. Since the urinary extravasation into the retroperitoneal space appeared to have improved with reduction of renal pelvic pressure by catheterization, a conservative observation was recommended. A follow-up non enhanced CT scan two weeks later confirmed resolution of extravasation. Chronic urinary retention due to an underactive bladder was suggested. Removal of urethral catheter was attempted with urapidil administration, but spontaneous urination did not occur. At the family’s request, the patient was discharged home while maintaining urethral catheterization. On a follow-up non enhanced CT scan three month later, no recurrence of urinary extravasation was observed, indicating its resolution.