Interventional Radiology · Supplementary · from Interventional Radiology
Case 3: Percutaneous Nephrostomy for Ureteral Obstruction
Patient Presentation
Demographics: 67-year-old female retired nurse
Chief Complaint: "I have severe right-sided flank pain with fever and chills for the past 2 days"
History of Present Illness: This 67-year-old female retired nurse presents to the emergency department with a 2-day history of progressive right flank pain, fever, and rigors. The pain is constant, dull, rated 7/10, and radiates to the right groin. She reports decreased urine output over the past 24 hours and dark-colored, malodorous urine. She has experienced nausea with two episodes of non-bloody, non-bilious vomiting.
She was diagnosed with locally advanced cervical cancer (stage IIIB squamous cell carcinoma) 18 months ago and completed concurrent chemoradiation with cisplatin and external beam radiation (50.4 Gy) followed by brachytherapy. Her most recent PET-CT 3 months ago showed no evidence of recurrence but noted moderate right hydroureteronephrosis with ureteral narrowing at the level of the pelvic brim, attributed to radiation-induced fibrosis. She was referred to urology but had not yet been seen.
Over the past 2 days, she developed fever to 39.8°C with rigors, worsening flank pain, and decreased urine output. Her primary care physician advised emergency department evaluation. On arrival, she appears acutely ill with sepsis physiology.
Past Medical History:
- Cervical cancer (stage IIIB squamous cell carcinoma), status post concurrent chemoradiation, in remission
- Radiation-induced right ureteral stricture with hydroureteronephrosis
- Hypertension
- Osteoporosis
- Chronic kidney disease stage 2 (baseline creatinine 1.3 mg/dL)
Medications:
- Amlodipine 5 mg daily
- Alendronate 70 mg weekly
- Calcium carbonate 600 mg with vitamin D twice daily
- Acetaminophen as needed
Social History:
- Retired nurse (40 years of critical care experience)
- Non-smoker
- No alcohol use
- Lives alone, independent in all ADLs
- Active in community volunteer work
Family History:
- Mother had breast cancer at age 70
- Father had coronary artery disease
- No family history of kidney disease
Physical Examination
- Vital Signs: BP 92/58 mmHg, HR 108 bpm, RR 22/min, Temp 39.8°C (103.6°F), SpO2 94% on room air
- General: Ill-appearing, diaphoretic female, shivering with rigors
- HEENT: Dry mucous membranes, no oral lesions
- Cardiac: Tachycardic, regular rhythm, no murmurs
- Lungs: Clear to auscultation, tachypneic
- Abdomen: Soft, mild right-sided tenderness without guarding or rebound. No palpable masses. Well-healed abdominal scar from prior port placement
- Back: Marked right costovertebral angle tenderness. No left CVA tenderness
- Pelvic: Radiation-related vaginal stenosis, no active bleeding or discharge
- Extremities: Cool, mottled peripherally. Delayed capillary refill (4 seconds)
- Skin: No rashes, radiation-related skin changes in the pelvis (telangiectasias, hyperpigmentation)
Workup and Results
Laboratory Studies:
| Test | Result | Reference Range |
|---|---|---|
| Hemoglobin | 10.8 g/dL | 12.0-16.0 g/dL |
| WBC | 18,400/μL | 4,500-11,000/μL |
| Neutrophils | 88% | 40-70% |
| Bands | 12% | 0-5% |
| Platelets | 98,000/μL | 150,000-400,000/μL |
| Creatinine | 3.2 mg/dL | 0.6-1.2 mg/dL (baseline 1.3) |
| BUN | 48 mg/dL | 7-20 mg/dL |
| Potassium | 5.4 mEq/L | 3.5-5.0 mEq/L |
| Sodium | 134 mEq/L | 136-145 mEq/L |
| Bicarbonate | 18 mEq/L | 22-29 mEq/L |
| Lactate | 4.2 mmol/L | 0.5-2.0 mmol/L |
| Procalcitonin | 12.4 ng/mL | <0.10 ng/mL |
| CRP | 248 mg/L | <10 mg/L |
| Blood cultures | Gram-negative rods (prelim) | No growth |
| Urinalysis | WBC >100/hpf, bacteria 3+, nitrite positive, leukocyte esterase 3+ | -- |
| Urine culture | Pending (later: E. coli >100,000 CFU/mL, ESBL-producing) | No growth |
Imaging/Additional Studies:
- CT abdomen/pelvis without contrast: Severe right hydroureteronephrosis with perinephric fat stranding. Right renal pelvis dilated to 3.5 cm. Right ureter dilated to the level of the pelvic brim where a segment of circumferential ureteral wall thickening and narrowing is seen over 2 cm (consistent with radiation-induced stricture). No ureteral calculi. Left kidney normal. Small amount of right perinephric fluid. No evidence of cancer recurrence
- Renal ultrasound: Right kidney 13.5 cm with severe hydronephrosis (AP pelvis diameter 3.8 cm). Thinned renal parenchyma (1.2 cm). Left kidney 11 cm, normal appearance
- Chest X-ray: No acute cardiopulmonary process
Clinical Image
Diagram illustrating percutaneous nephrostomy tube placement in a hydronephrotic kidney with ureteral obstruction, showing the catheter path through the flank into the dilated renal pelvis. Source: Educational illustration.
Diagnosis
Obstructive Uropathy with Pyonephrosis and Urosepsis Secondary to Radiation-Induced Right Ureteral Stricture
Key Diagnostic Criteria:
- Severe right hydroureteronephrosis on CT with perinephric fat stranding
- Ureteral stricture at the pelvic brim consistent with radiation fibrosis
- Sepsis criteria met: fever, tachycardia, hypotension, leukocytosis with bandemia, elevated lactate and procalcitonin
- Obstructive acute kidney injury (creatinine elevated from baseline 1.3 to 3.2 mg/dL)
Treatment Plan
- Immediate resuscitation: IV crystalloid bolus (30 mL/kg), broad-spectrum antibiotics (piperacillin-tazobactam 4.5 g IV q8h, adjusted when culture sensitivities available), vasopressors (norepinephrine) if hypotension persists after fluid resuscitation
- Emergency percutaneous nephrostomy (PCN): Performed within 6 hours of presentation under ultrasound and fluoroscopic guidance. Patient placed prone with right side elevated. Ultrasound-guided access into the right lower pole posterior calyx using a 21-gauge needle. Guidewire advanced into the renal pelvis. Sequential dilation and placement of a 10F locking pigtail nephrostomy catheter. Return of 200 mL of turbid, purulent urine (sent for culture). Catheter secured to skin and connected to external drainage bag
- Post-procedure monitoring: ICU admission for sepsis management. Monitor urine output (expect post-obstructive diuresis), electrolytes every 6 hours for 48 hours, renal function daily. Replace fluids and electrolytes as needed during post-obstructive diuresis (typically 200-500 mL/hour initially)
- Antibiotic adjustment: Transition to ertapenem 1 g IV daily based on ESBL-producing E. coli sensitivity results. Total antibiotic course of 14 days
- Definitive management: After sepsis resolution and renal function stabilization, antegrade nephrostogram at 4-6 weeks to assess stricture length and location. Options include antegrade ureteral stent placement, balloon dilation of the stricture, or chronic nephrostomy drainage. Long-term consideration for ureteral reimplantation or ileal ureter if stricture is not amenable to endourologic management
- Surveillance: Continue oncologic surveillance for cervical cancer recurrence. Monitor renal function with serial labs and imaging
Key Learning Points
- Obstructed infected urinary system (pyonephrosis) is a urologic emergency requiring emergent drainage; antibiotics alone are insufficient and mortality is high without decompression
- Percutaneous nephrostomy is preferred over retrograde ureteral stent placement in the setting of urosepsis because it provides immediate external drainage without the need to traverse the obstruction or introduce additional instrumentation through the infected system
- The preferred access for PCN is through a lower pole posterior calyx, which minimizes risk of vascular injury and provides optimal drainage of the collecting system
- Post-obstructive diuresis can be significant (>200 mL/hour) and requires careful monitoring of fluid balance, electrolytes (sodium, potassium, magnesium, phosphorus), and renal function for 48-72 hours
- Radiation-induced ureteral strictures typically occur 6-24 months after pelvic radiation, most commonly at the pelvic brim where the ureter is relatively fixed; they affect 1-5% of patients receiving pelvic radiation therapy