Purpose of Nephrostomy Tube
A nephrostomy tube serves two primary purposes: (1) emergency urinary decompression in cases of obstructed and infected renal collecting systems (pyonephrosis) or acute renal failure from obstruction, and (2) providing percutaneous access to the renal collecting system for endourologic procedures such as stone removal. 1
Primary Clinical Indications
Emergency Urinary Decompression
The nephrostomy tube functions as a drainage catheter placed into the renal collecting system to relieve obstruction. This is critical in:
- Acute obstructive uropathy with sepsis or acute renal failure - This represents a medical emergency where percutaneous nephrostomy (PCN) provides immediate urinary decompression 1
- Pyonephrosis (obstructed, infected collecting system) - PCN is potentially lifesaving in this setting 2
- Declining renal function from obstruction - When conservative management is inadequate 1
The tube permits either external urinary drainage (standard PCN catheter) or internal drainage through a longer catheter component that extends through the ureter into the bladder (percutaneous nephroureteral catheter or PCNU) 1.
Procedural Access for Endourologic Surgery
Beyond drainage, nephrostomy tubes facilitate:
- Stone interventions - Particularly when stone burden is too large for extracorporeal shock-wave lithotripsy, PCN access enables percutaneous stone removal 1
- Endopyelotomy - For ureteropelvic junction stenoses, offering less morbidity than open pyeloplasty 1
- Diagnostic testing - Including brush biopsy for suspected malignant strictures 1
Technical Performance and Safety Profile
PCN placement achieves near-100% technical success when accessing dilated collecting systems using image guidance (ultrasound for initial access, then fluoroscopy), with the Society of Interventional Radiology setting quality thresholds at 95% for urinary obstruction without stones 1. Success rates drop to 80-90% for non-dilated systems 1.
Complication Rates
The procedure demonstrates a strong safety record:
- Overall complication rates: 6.3-10% in most series 1
- Septic shock: ≤4% (10% in pyonephrosis) 1
- Hemorrhage requiring transfusion: ≤4% 1
- Mild hematuria occurs in ~50% but is clinically insignificant 1
Important caveat: Complication rates are substantially higher in patients with advanced malignancies 1.
Clinical Decision-Making: PCN vs. Retrograde Ureteral Stenting
The choice between nephrostomy and retrograde stenting depends on specific clinical scenarios:
Favor PCN when:
- Retrograde stenting has failed (PCN shows 100% technical success vs. 80% for retrograde stenting) 1
- Patient is high-risk for anesthesia 1
- Pyonephrosis requires larger tube decompression 1
- Complex anatomy (e.g., urinary diversion after cystectomy) makes retrograde access difficult 1
Retrograde stenting may be preferred when:
- Patient has obstructing ureteral stones with sepsis - associated with shorter hospital stays and lower ICU admission rates, though higher fever rates 1
- Avoiding percutaneous access morbidity is priority 1
Special Populations
Pregnant patients (>20 weeks): Both PCN and retrograde stenting are viable options, with fluoroscopy typically avoided. The choice depends on technical feasibility and institutional expertise 1.
Post-cystectomy with urinary diversion: PCN is generally preferred over retrograde approaches due to difficulty visualizing ureteric openings in bowel conduits and navigating altered anatomy 1.
Duration and Maintenance
Standard nephrostomy tubes require monthly changes, while specialized circle nephrostomy tubes can remain indwelling for approximately 168 days (semi-annual changes), offering significant cost savings for patients requiring chronic drainage 3.