Why Would Someone Have Both a Nephrostomy and a Urostomy?
A patient requires both a nephrostomy and a urostomy when there is obstruction at the level of the ureteroenteric anastomosis (where the ureter connects to the bowel conduit) that cannot be bypassed with retrograde stenting, necessitating percutaneous drainage to preserve renal function and prevent complications like pyonephrosis or urosepsis.
Clinical Context and Mechanism
The scenario of having both drainage systems simultaneously occurs almost exclusively in patients who have previously undergone cystectomy with urinary diversion (urostomy/ileal conduit). The urostomy is the permanent urinary diversion created at the time of bladder removal, while the nephrostomy becomes necessary when complications develop 1.
Why Retrograde Access Fails
When obstruction develops at the ureteroenteric anastomosis in patients with ileal conduits:
- Anatomical challenges make retrograde stenting extremely difficult - visualizing the ureteric opening in the bowel conduit is challenging, and navigating the angulations and curvature of the reconstructed anatomy often proves impossible even with flexible endourologic instruments 1
- Retrograde access is typically attempted first but has limited success rates 1
- When retrograde approaches fail, percutaneous nephrostomy becomes necessary to decompress the obstructed kidney 1
Specific Clinical Scenarios
Malignant Obstruction
The most common reason is stricture or obstruction from recurrent malignancy at the ureteroenteric anastomosis. These patients may require permanent nephrostomy drainage because the obstruction cannot be crossed 1.
Anastomotic Stricture
Benign strictures at the ureteroenteric anastomosis can develop over time, requiring nephrostomy when:
- Declining renal function is documented
- Pyonephrosis develops
- The loopogram shows no reflux into the distal ureters, indicating inherent stricture 1
Bridge to Definitive Repair
Nephrostomy can serve as a temporizing measure while maintaining the existing urostomy, allowing for delayed reconstructive surgery in an elective setting when the patient is too unstable for immediate complex urological reconstruction 2.
Technical Considerations
Why Not Remove the Urostomy?
The urostomy remains functional for:
- Draining urine from the contralateral (non-obstructed) kidney
- Providing a potential route for future retrograde interventions
- Avoiding additional major surgery in already compromised patients
Preference for Internal/External Catheters
When nephrostomy is placed in patients with urostomies, percutaneous nephroureterostomy (PCNU) catheters are generally preferred over internal double-J stents because double-J stents tend to occlude quickly from mucous plugging within the ileal conduit 1.
Common Pitfalls
- Do not assume both drainage systems indicate treatment failure - this is often the appropriate management for complex ureteroenteric obstruction
- Recognize that mucous plugging is a significant issue - internal stents alone frequently fail in ileal conduits 1
- Understand this is typically not a permanent situation - many patients can eventually be converted to internal drainage once the acute issue resolves or definitive reconstruction is performed 2
Prognosis and Quality of Life
The decision to place nephrostomy in patients with advanced pelvic malignancy and existing urostomies requires careful consideration. Not all obstructed kidneys require drainage, and improvement in laboratory renal function does not necessarily translate to improved quality of life 3. Individual assessment is critical, particularly in patients with disseminated disease where intervention may not provide meaningful benefit 3.