A Dynamic Anatomical Description of the Parietal Pleura Setting Safety Limits for Intercostal Percutaneous Access.

Purpose: We came up with a dynamic anatomical study intended to validate the safety of intercostal approach used by our center to access the upper pole of the kidney during percutaneous surgery.

Materials And Methods: A total of 101 patients presenting randomly to the radiology department for CT evaluation of the abdomen and superior pelvis were involved in this study. Deep inspiration and expiration sequences in the prone position were evaluated to establish the location of the parietal pleura in relation to different anatomical landmarks. Three-dimensional reconstruction was performed to simulate the access needle course through the retroperitoneum.

Results: Our data show that the position of parietal pleura is invariably higher on the right side irrespective of anatomical relation or respiratory changes. Higher position of the parietal pleura was noted in all considered landmarks upon full expiratory sequences. Using the midclavicular line as a landmark, our data show that on the right side, the parietal pleura was higher than the 10th intercostal space (ICS) in 100% of patients. Going up to the level of the ninth and eighth ICS, the pleura is higher in 89.1% and 66.3% of patients, respectively. Moreover, on the left side, the level of the parietal pleura was higher than the 11th ICS in 100% of patients. Reaching the 10th ICS, the parietal pleura still is higher in 92.07% of cases. Going up to the ninth ICS reduces the margin to 64.35% and using the eighth ICS would convey a margin of 24.7%.

Conclusions: Supracostal access for percutaneous nephrolithotomy carries a risk of pulmonary complications, limiting its use worldwide. We have shown in this study that using the differences in inspiration and expiration along with the right anatomical landmarks could substantially lower the risk of complications. However, regardless of the side or landmark used, supracostal access is safe in >90% of cases.