Lower-pole fluoroscopy-guided percutaneous renal access: which calix is posterior?

Area of Science:

• Radiology
• Urology
• Anatomy

Background:

• Percutaneous renal access relies on accurate identification of posterior calices.
• Current understanding often misidentifies the most medial calix as posterior.

Purpose of the Study:

• To determine the true orientation of lower-pole calices.
• To define optimal sites for percutaneous renal access via posterior calices.

Main Methods:

• Retrospective review of 101 contrast-enhanced CT scans.
• Analysis of lower-pole caliceal anatomy, including number and orientation.
• Two observers evaluated axial and coronal CT images.

Main Results:

• The most medial lower calix was anterior facing in 94.1% of kidneys.
• It was the most anterior positioned calix in 83.2% of kidneys.
• Only 8.9% of medial calices were the most posterior.

Conclusions:

• The medial lower calix is predominantly anterior, contrary to common assumptions.
• Percutaneous access should target more lateral calices for posterior orientation.
• Accurate caliceal identification is crucial for successful percutaneous nephrolithotomy.