Intercostal Vessels and Nerves are at Risk for Injury During Supracostal Percutaneous Nephrostolithotomy

Purpose: We characterized key intercostal anatomical relationships relevant to supracostal percutaneous nephrostolithotomy using anatomical dissection. Materials and Methods: We performed 20 cadaveric dissections of the 11th intercostal space to characterize key anatomical relationships relevant to percutaneous upper pole renal access. Specific data recorded included intercostal rib distance at the lateral border of the paraspinous muscles, and the mid scapular and posterior axillary lines. We also recorded the distance between the 12th and 11th ribs to the intercostal nerve, artery and vein at the same 3 sites. Results: The average intercostal distance was 21, 23 and 26 mm at the lateral border of the paraspinous muscles, and the mid scapular and posterior axillary lines, respectively. The intercostal nerve was exposed to injury in 85%, 100% and 100% of patients at the 3 sites, respectively. The intercostal artery was exposed below the 11th rib in 30%, 60% and 70% of cadavers, respectively, and it was 6 mm from the rib in 25% of interspaces. The intercostal vein, which was exposed below the 11th rib in 0%, 5% and 10% of cadavers, respectively, was least likely to be injured. Conclusions: Intercostal vessels are at risk for damage during percutaneous nephrostolithotomy in a significant number of patients. Access placement lateral to the paraspinous muscles and in the lower half of the 11th intercostal space may decrease damage to the intercostal artery and nerve. Injury to the intercostal vessels and nerve may explain the increased risk of bleeding and pain during supracostal percutaneous nephrostolithotomy. Minimizing injury may decrease blood loss and pain.