Radiologic Relation of the Colon to the Trajectory of Percutaneous Nephrolithotomy Access in Prone Versus Flank-free Modified Supine Position: A Prospective Study of Intra and Interindividual Influencing Factors

The distance between the colon and assumed PCNL trajectory at a puncture on the posterior axillary line was influenced mainly by patient position. In FFMS position the colon appears to be farther than in prone position. BMI and age significantly influence this distance to a lesser extent.