What is the best approach for managing a large kidney stone in an 85-year-old patient with potential comorbidities?

Management of Large Kidney Stones in an 85-Year-Old Patient

Percutaneous nephrolithotomy (PCNL) remains the first-line treatment for large kidney stones (>20 mm) in elderly patients, including those aged 85, as it provides superior stone-free rates (74-87%) compared to other modalities, with comparable safety profiles to younger patients when comorbidities are appropriately managed. 1, 2

Initial Assessment and Risk Stratification

Before proceeding with any intervention in an 85-year-old patient, several critical factors must be evaluated:

• Assess for active infection: If purulent urine is encountered or the patient shows signs of sepsis with an obstructing stone, abort any definitive stone procedure immediately and establish urgent drainage with either percutaneous nephrostomy or ureteral stent, along with broad-spectrum antibiotics 1, 2
• Evaluate bleeding risk: Patients on antithrombotic therapy require referral to internal medicine for appropriate therapeutic adjustments before stone management, as PCNL is classified as a high-bleeding-risk procedure 3, 2
• Screen for untreated UTI: This is an absolute contraindication to PCNL and must be treated before proceeding 3, 2
• Assess renal function: If the affected kidney has negligible function with chronic infection, nephrectomy may be the most appropriate option to prevent recurrent morbidity 3, 2

Primary Treatment Recommendation: PCNL

For an 85-year-old with a large kidney stone, PCNL should be the first treatment utilized, as studies demonstrate comparable stone-free rates and only slightly higher minor complication rates in elderly patients compared to younger cohorts. 4

Technical Approach for Elderly Patients

• Access planning: Upper pole access typically provides optimal visualization of the entire collecting system for large stones 1
• Miniaturized techniques: Consider 18 Fr Mini-PCNL (12-22 F) as it provides similar stone-free rates (86%) to standard PCNL while reducing blood loss, transfusion rates (7% overall), and hospital stay without significant differences in major complications 3, 2, 5
• Positioning options: Both prone and supine positions are equally safe; supine allows simultaneous retrograde access if needed 3, 2
• Imaging guidance: Ultrasound guidance reduces radiation exposure and has lower complication rates compared to fluoroscopy alone, which is particularly relevant in elderly patients 3, 2

Procedural Essentials

• Flexible nephroscopy is mandatory during PCNL to access fragments in areas inaccessible by rigid nephroscope, preventing residual stones 1, 2
• Normal saline irrigation only: This prevents hemolysis, hyponatremia, and electrolyte abnormalities that elderly patients tolerate poorly 1, 2
• Antibiotic prophylaxis: Administer within 60 minutes of procedure based on prior urine cultures and local antibiogram 1, 2

Post-Procedure Management

• Drainage considerations: Tubeless PCNL (ureteral stent alone without nephrostomy) is acceptable if there is no active hemorrhage and reduces pain and hospital stay 3, 2
• Small-bore nephrostomy tubes reduce post-operative pain when drainage is required 3, 2
• Expected outcomes: Average 1.3 procedures needed for complete clearance, with hospital stay typically 1-5 days and return to normal activities within 1-2 weeks 1

Alternative Approach: Staged Ureteroscopy (URS)

If PCNL is contraindicated due to uncorrectable coagulopathy, severe anatomic derangements, or patient preference for less invasive approach, staged flexible ureteroscopy with laser lithotripsy is a viable alternative. 1

When to Consider URS Instead

• Uncorrectable bleeding disorders: URS is classified as a low-bleeding-risk procedure 3
• Patient preference for avoiding percutaneous access: Studies show elderly patients tolerate URS well with minimal complications and comparable stone-free rates for stones up to 2 cm 4, 5
• Severe skeletal malformations preventing proper positioning for PCNL 3

URS Technical Considerations

• Multiple staged procedures required: For large stones (>2 cm), expect to perform 2-3 sessions to achieve stone-free status 1, 5
• Stone-free rate: Approximately 79% for large renal stones, lower than PCNL but with overall complication rate of only 11% 5
• Hospital stay: Shorter (1.56 days average) compared to PCNL 5
• Post-procedure stenting: Only necessary if there is trauma, residual fragments, bleeding, or perforation; routine stenting increases morbidity 3

What NOT to Do

Extracorporeal shockwave lithotripsy (ESWL) monotherapy should NOT be used for large kidney stones in any patient, including the elderly, as it produces significantly lower stone-free rates (approximately 67%) and requires multiple auxiliary procedures. 3

ESWL Limitations

• Contraindicated if: Bleeding disorders present, uncontrolled UTI, severe obesity, or arterial aneurysm near the stone 3
• Poor outcomes for large stones: Stone-free rates dramatically decrease with increasing stone burden 3
• High auxiliary procedure rate: 6-9% require additional interventions 3

Critical Safety Considerations for Elderly Patients

Complication Profile in the Elderly

Research specifically examining elderly patients found:

• PCNL complications: Slightly higher rate of minor (Clavien I-II) complications but comparable major complication rates, with fever (10.8%), transfusion requirement (7%), and sepsis (0.5%) being most common 2, 4
• No difference in operative time or stone-free rates compared to younger patients 4
• Cardiovascular monitoring: ESWL can cause dysrhythmias (11-29%), which is particularly relevant in elderly patients with cardiac comorbidities 3

Anesthesia Considerations

• General anesthesia risks must be weighed, though URS has no specific contraindications beyond this 3
• Spinal anesthesia is often better tolerated in elderly patients for PCNL procedures

Decision Algorithm for the 85-Year-Old Patient

1. First: Rule out active infection/sepsis → if present, drain urgently and defer definitive treatment 1, 2
2. Second: Assess bleeding risk and optimize anticoagulation status 3, 2
3. Third: Evaluate renal function → if negligible, consider nephrectomy 3, 2
4. Fourth: If stone >20 mm and patient is medically optimized → proceed with PCNL (preferably Mini-PCNL) 1, 2, 5
5. Fifth: If PCNL contraindicated or patient refuses → staged flexible URS 1, 4
6. Never: Use ESWL monotherapy for large stones 3

Common Pitfalls to Avoid

• Failing to perform flexible nephroscopy during PCNL results in residual fragments and future stone events 1, 2
• Using non-isotonic irrigation increases risk of hemolysis and electrolyte disturbances that elderly patients tolerate poorly 1, 2
• Routine post-URS stenting when unnecessary increases morbidity without benefit 3
• Underestimating infection risk: Elderly patients have higher rates of postoperative fever and sepsis, making antibiotic prophylaxis and sterile urine critical 2