Management of Obstructive Uropathy
The management of obstructive uropathy requires urgent decompression for cases with sepsis, acute kidney injury with significant renal dysfunction, or bilateral obstruction/obstruction of a solitary functioning kidney, with percutaneous nephrostomy (PCN) being the preferred first-line approach for septic patients. 1
Initial Assessment and Indications for Urgent Intervention
- Determine if the patient has signs of sepsis, assess renal function, electrolyte abnormalities, and obtain urinalysis to check for blood and infection 1
- CT scan is recommended to identify hydronephrosis, perinephric stranding, and potential causes of obstruction 1
- Urgent decompression is indicated for:
- Pyonephrosis/obstructive pyelonephritis with sepsis
- Acute kidney injury with significant renal dysfunction
- Bilateral obstruction or obstruction of a solitary functioning kidney 1
Decompression Methods
Percutaneous Nephrostomy (PCN)
- First-line approach for septic patients, with a 92% survival rate compared to 60% with medical therapy alone 1
- Preferred for extrinsic compression of the ureter, obstruction involving the ureterovesical junction, and when retrograde access is challenging 1
- Technical success rates approach 100% when accessing dilated collecting systems and 80-90% for non-dilated systems 2
- Complication rates are generally low (approximately 10%), with the UK registry reporting even lower rates at 6.3% 2
- Common complications include catheter displacement, bleeding, and sepsis 2
Retrograde Ureteral Stenting (RUS)
- First-line therapy for management of ureteral obstruction caused by gynecologic malignancies 2
- Preferred when a patient requires general anesthesia for other procedures 1
- PCN may have higher technical success rates compared to RUS, especially in cases of extrinsic compression, obstruction involving the ureterovesical junction, or ureteral obstruction length >3 cm 2
- Patients receiving PCN have lower rates of hematuria and dysuria post-operatively compared to RUS, though with slightly longer hospitalization duration 3
Percutaneous Antegrade Ureteral Stenting
- Usually performed 1-2 weeks following initial placement of a diverting PCN 2
- Double-J ureteral stents are better tolerated than percutaneous nephroureteral catheters 2
- In one study, technical success was achieved in 91.8% of cases with clinical success in 89.8% of patients 2
Medical Management
- Without evidence of declining renal function or infection, conservative management could be considered until clinical status changes 2
- Medical management is primarily indicated for preprocedural antibiotic treatment and postprocedural care in cases of obstructing stone disease with sepsis 2
- For palliative purposes and comfort care in advanced malignancy, conservative management may be appropriate but does not address the underlying etiology 2
- Third-generation cephalosporins show superiority over fluoroquinolones in clinical and microbiological cure rates for suspected urosepsis 1
Special Considerations
Malignant Obstruction
- PCN improves renal function in most cases, but patient selection is critical 1
- For palliative cases, consider quality of life impact as PCN may offer little benefit when survival is limited 1
- PCN can be valuable in improving renal function and survival in patients with prostate carcinoma and transitional cell carcinoma 2
Post-Urinary Diversion
- Image-guided percutaneous antegrade access is generally preferred due to difficulty visualizing the ureteric opening in the bowel conduit 1
- Retrograde PCNU catheters are generally preferred over retrograde "internal" double-J ureteral stents because the latter tend to occlude quickly due to mucous plugging within the ileal conduit 2
Post-Obstructive Complications
- Monitor for post-obstructive diuresis, characterized by excessive urine output and natriuresis, especially in patients with bilateral obstruction or obstruction of a solitary functioning kidney 4
- Watch for electrolyte abnormalities, including hyponatremia, hypokalemia, and hypophosphatemia 4
- Risk of developing pyelonephritis or asymptomatic bacteriuria after PCN placement, with neutropenia and history of urinary tract infection being significant risk factors 1