Retro-peritoneoscopy: anatomical rationale for direct retroperitoneal access.

Although the upper urinary tract resides at an extraperitoneal location, the traditional laparoscopic approach to these organs has been transperitoneal. Several investigators have advocated using a direct approach to the retroperitoneum to minimize risks associated with transperitoneal surgery. We performed autopsy and radiographic studies in an effort to define the location of the retroperitoneum relative to surface anatomy. These investigations indicate that the peritoneal reflection was consistently anterior to the posterior axillary line. Moreover, when a patient was placed in the lateral position, the anteroposterior extent of the potential retroperitoneal space increased 2-fold. Based on these studies, a technique for direct retro-peritoneoscopy was initiated and successfully performed in 21 of 23 patients. Direct access to the retroperitoneum can be performed in a reliable and safe manner.