What are the different procedures for treating kidney stones?

Explaining Kidney Stone Procedures to Patients

The most effective approach to treating kidney stones is through minimally invasive procedures, with percutaneous nephrolithotomy (PCNL) being the gold standard for larger stones, while ureteroscopy (URS) and extracorporeal shock wave lithotripsy (ESWL) are preferred for smaller stones based on their location and composition. 1

Main Procedural Options

Extracorporeal Shock Wave Lithotripsy (ESWL)

• Uses shock waves generated outside the body to fragment stones into smaller pieces that can pass naturally 1
• Best for stones <10 mm, particularly in the kidney or upper ureter 1
• Advantages: Least invasive, typically outpatient, minimal recovery time 1
• Disadvantages: Lower stone-free rates (especially for larger stones), may require multiple sessions 1
• Common complications: Steinstrasse (4%), hematuria (17.2%), pain (12.1%), and potential for residual fragments (21-59%) 1
• Contraindicated in pregnancy, bleeding disorders, uncontrolled UTIs, severe obesity, and when anatomical obstructions exist distal to the stone 1

Ureteroscopy (URS)

• Uses a small scope inserted through the urethra to directly visualize and treat stones 1
• Flexible URS is increasingly favored due to technical advances 1
• Best for ureteral stones and smaller renal stones 1
• Advantages: High success rates, especially for distal ureteral stones 1
• Disadvantages: Requires anesthesia, potential for ureteral injury 1
• No specific contraindications aside from general anesthesia risks and untreated UTIs 1

Percutaneous Nephrolithotomy (PCNL)

• Involves creating a small tract through the skin directly into the kidney to remove stones 1
• Standard treatment for large renal stones (>20 mm) and staghorn calculi 1
• Variations include standard PCNL (>22 F) and mini-PCNL (12-22 F) 1
• Advantages: Highest stone-free rates for large stones, direct visualization of the collecting system 1
• Disadvantages: More invasive, longer hospital stay, higher complication rates 1
• Complications include fever (10.8%), need for transfusion (7%), thoracic complications (1.5%), and sepsis (0.5%) 1

Combination Therapy

• Some patients benefit from combined approaches, particularly PCNL followed by ESWL 1
• PNL is performed initially to remove as much stone as possible, followed by ESWL to fragment remaining stones 1
• This approach is becoming less common as endoscopic and intracorporeal lithotripsy technology improves 1

Open/Laparoscopic/Robotic Surgery

• No longer first-line therapy for most patients with stones 1
• Reserved for rare cases with anatomic abnormalities, very large or complex stones, or those requiring concomitant reconstruction 1

Factors Affecting Procedure Selection

Stone Characteristics

• Size: Stones <10 mm are suitable for ESWL; larger stones (>20 mm) typically require PCNL 1
• Location: Lower pole stones respond less well to ESWL 1
• Composition: Hard stones (calcium oxalate monohydrate, cystine) are less responsive to ESWL 1

Patient Factors

• Obesity may limit ESWL effectiveness 1
• Bleeding disorders require special consideration before PCNL or ESWL 1
• Pregnancy contraindicates ESWL 1
• Anatomical abnormalities may require specialized approaches 1

Post-Procedure Considerations

Recovery Expectations

• ESWL: Typically outpatient, return to normal activities within 1-2 days 1
• URS: Usually outpatient or 24-hour stay, return to normal activities within 3-7 days 1
• PCNL: Hospital stay of 1-5 days, return to normal activities within 1-2 weeks after removal of drainage tubes 1

Follow-up Care

• Stone analysis is recommended for all retrieved stones to guide prevention strategies 1
• Residual fragments should be addressed, especially if infection stones are suspected 1
• Follow-up imaging is essential to confirm stone clearance 1

Prevention of Recurrence

• Increased fluid intake and dietary modifications are recommended for all stone formers 2
• Medications may be prescribed based on stone composition and metabolic abnormalities 2
• Regular follow-up is important as recurrence rates can be up to 50% within 5 years 3

Common Pitfalls and Caveats

• Untreated UTIs must be addressed before any stone procedure to prevent sepsis 1
• Residual fragments after procedures may lead to stone regrowth and recurrent symptoms in up to 43% of patients 1
• Antimicrobial prophylaxis should be administered prior to stone intervention based on prior urine culture results and local antibiogram 1
• If purulent urine is encountered during a procedure, it should be aborted, drainage established, and antibiotics continued 1