Editing Functional: Urinary Fistulae (section)

== Urovascular fistulae ==

=== Renovascular and pyelovascular fistulae ===

==== Causes ====
* '''Most common causes are procedures in which percutaneous renal access is required, such as PCNL.''' Alternatively, a long-term indwelling nephrostomy tube may lead to pyelovascular fistula formation.

==== Diagnosis and Evaluation ====
* '''Patients may have life-threatening hemorrhage and hypovolemic shock, or intermittent gross hematuria'''
* ≈75% of patients with renovascular fistulae have an abdominal bruit

==== Management ====
* '''Depends on the cause of the fistula and the associated clinical manifestations'''
** '''Patients with severe hemorrhage on removal of the nephrostomy tube can be temporized in some instances by replacing the tube, or, in large mature tracts, by placing a Foley catheter to tamponade the bleeding.'''
** '''In patients with ongoing bleeding, transcatheter angiographic embolization of the lacerated vessel is recommended.'''
** '''≈70% of fistulae occurring after needle biopsy of the kidney close spontaneously within 18 months, thus, expectant management is an appropriate first step'''
** '''Fistulae due to renal cell carcinoma warrant nephrectomy'''

=== Ureterovascular fistula ===

==== Causes ====
*'''Most reported ureterovascular fistulae are ureteroiliac artery fistulae''', although ureteroiliac vein fistulae have been reported as well.
* '''Risk factors for ureteroarterial fistulae:'''
** '''Prior history of vascular disease'''
** '''Radiation therapy''' and/or pelvic surgery, especially in the setting of '''indwelling ureteral stents.'''

==== Diagnosis and Evaluation ====
*Ureterovascular fistulae may manifest with microscopic hematuria, intermittent gross hematuria, or life-threatening exsanguinating hemorrhage.

==== Management ====
* In a stable patient with a suspected ureterovascular fistula, radiographic evaluation can be used for diagnostic purposes and treatment planning (reconstructive options or angiographic embolization).
* In the unstable patient, surgical intervention must be considered early, especially because radiographic evaluation may be nondiagnostic.