What are the differences between supra 11th, supra 12th, and infracostal (below the ribs) puncture approaches in percutaneous nephrolithotomy (PCNL)?

Differences Between Supra 11th, Supra 12th, and Infracostal Puncture in PCNL

Infracostal puncture (below the 12th rib) should be the preferred approach for PCNL due to significantly lower risk of thoracic complications, while supracostal access (above the 11th or 12th rib) should be reserved for specific anatomical indications despite comparable stone clearance rates. 1

Anatomical Definitions and Access Points

• Supra 11th rib puncture: Access through the 11th intercostal space, representing the highest and most superior approach to the kidney 2
• Supra 12th rib puncture: Access through the 12th intercostal space, positioned between the 11th and 12th ribs 3, 4
• Infracostal puncture: Access below the 12th rib, avoiding intercostal spaces entirely 1, 3

Stone Clearance Efficacy

The stone-free rates are comparable across all approaches, making safety the primary differentiating factor:

• Supracostal access (11th or 12th rib): Stone clearance rates of 86.4-97.3% with secondary procedures 2, with 90% achieving stone-free or clinically insignificant residuals 4
• Infracostal access: Stone clearance rate of 94.1%, not statistically different from supracostal approaches 3
• Meta-analysis confirms no significant difference in stone-free rates between supracostal and infracostal access (OR = 1.18, P = 0.41) 1

Complication Profiles: The Critical Difference

Thoracic Complications

Supracostal puncture carries a 10-fold higher risk of hydrothorax/hemothorax compared to infracostal access (OR = 10.47, P < 0.00001) 1:

• Supra 11th/12th rib: Pleural complications occur in 5-15% of cases 2, 4, 5, including pneumothorax, pleural effusion, and hemothorax 5
• Infracostal: Pleural complications approach 1% 6
• Respiratory-correlated pain is significantly more common with supracostal access (32% vs 5%) 5

Bleeding Complications

• Supracostal access results in significantly greater mean hemoglobin drop (1.86 g/L higher reduction, P = 0.02) 1
• Risk of intercostal artery injury exists with supracostal approaches 4
• Blood transfusion rates show no statistical difference between approaches (OR = 0.88, P = 0.70) 1

Other Complications

• No significant differences in fever rates (OR = 1.39, P = 0.09) 1
• Hospital length of stay is comparable (MD = 0.17 day, P = 0.10) 1
• Need for additional procedures is similar (OR = 1.09, P = 0.71) 1

Clinical Indications for Supracostal Access

Despite higher complication rates, supracostal puncture is indicated for specific stone configurations:

• Large pelvic stones with major bulk extending superiorly 2
• Partial or complete staghorn calculi requiring superior access 2, 4
• Superior calyceal stones with major stone burden above the 12th rib level 2, 4
• Upper ureteric stones requiring antegrade access 2, 4
• High-lying kidneys where infracostal access is anatomically impossible 4

Essential Safety Precautions

For Supracostal Puncture (11th or 12th Rib)

• Mandatory chest X-ray immediately post-procedure to detect pneumothorax or pleural effusion 4
• Access should be obtained during end-expiration to minimize pleural transgression 5
• CT guidance may reduce complications compared to fluoroscopy/ultrasound alone for supracostal access 5
• Chest tube insertion equipment must be immediately available 4

General PCNL Safety Standards

• Normal saline irrigation must be used to prevent electrolyte abnormalities 6
• Flexible nephroscopy should be routine to prevent residual fragments 6
• Complication thresholds: pleural complications from PCNL should not exceed 15% 6

Algorithmic Approach to Access Selection

Step 1: Assess stone location and burden on preoperative CT imaging

Step 2: If stone is accessible via infracostal approach → Choose infracostal access (safest option) 1

Step 3: If stone requires superior access (staghorn, upper pole, high-lying kidney) → Consider supracostal access 2, 4

Step 4: For supracostal access:

• Use 12th intercostal space preferentially over 11th space when possible 2
• Ensure CT or ultrasound guidance 5
• Obtain access during end-expiration 5
• Perform mandatory post-procedure chest X-ray 4

Step 5: Have chest tube insertion capability immediately available for supracostal cases 4

Common Pitfalls to Avoid

• Avoiding supracostal access entirely when it provides optimal stone clearance for complex upper pole stones 2, 4
• Failing to obtain post-procedure chest X-ray after supracostal puncture, missing asymptomatic pneumothorax 4
• Using non-isotonic irrigation increases hemolysis and electrolyte disturbance risk 6
• Omitting flexible nephroscopy leads to residual fragments and recurrence 6