Percutaneous nephrolithotomy in the prone and prone-flexed positions: anatomic considerations

Area of Science:

• Urology
• Anatomy
• Surgical Positioning

Background:

• Percutaneous nephrolithotomy (PCNL) is a key procedure for kidney stone removal.
• Patient positioning is critical in PCNL to optimize surgical access and minimize risks.
• The prone position is standard, but anatomical variations necessitate exploring alternative positions.

Purpose of the Study:

• To evaluate the anatomical basis and benefits of a prone-flexed position for PCNL.
• To compare the prone-flexed position with supine and standard prone positions regarding organ proximity and access.
• To assess the impact of prone-flexed positioning on surgical safety and efficacy.

Main Methods:

• Triphasic computed tomography (CT) scans were performed in supine, prone, and prone-flexed positions.
• Anatomical relationships of kidneys and adjacent organs were analyzed.
• A 30-degree angle simulated nephrostomy access to assess organ injury risk.

Main Results:

• Prone-flexed positioning improved access to the upper pole and increased mobility for lower pole PCNL.
• Compared to supine, prone and prone-flexed positions reduced the risk of liver and spleen injury during upper pole access.
• The prone-flexed position increased the distance to ribs, facilitating access and potentially avoiding injury to adjacent organs like the colon.

Conclusions:

• The prone-flexed position is a simple, well-tolerated modification for PCNL.
• It offers significant advantages in terms of improved access and reduced risk of iatrogenic injury.
• This position enhances surgical options for both upper and lower pole kidney stone treatments.