Direct puncture tunnel method for establishing the retroperitoneal cavity: anatomic confirmation and clinical experience.

Purpose: The feasibility and safety of the direct puncture tunnel method to establish the retroperitoneal cavity was assessed by CT and clinical experience. Materials and Methods: Ten patients who underwent retroperitoneoscopic procedure were scanned by CT in the lateral decubitus position. The distance between the lumbar fascia and psoas major muscle (L-P distance) on the puncture line was measured. The angle between the puncture line and the posterior colon margin (P-C angle) was also measured. In total, 292 patients who underwent retroperitoneoscopic procedure were used to establish the retroperitoneal cavity using the direct puncture tunnel method, and complications in these patients were evaluated. Results: The average L-P distance was 25.0 mm (left side) and 25.5 mm (right side) in the lateral decubitus position. The average P-C angle was 26.8 degrees (left side) and 29.7 degrees (right side). The retroperitoneal cavity was well established in all 292 patients, and no visceral or blood vessel injury occurred. Conclusions: CT scans in the lateral recumbent position indicate that there are no visceral and large blood vessels on the puncture path. The scans also provide a window for inserting the first trocar blindly into the retroperitoneum. A high success rate and low complication rate were observed clinically for the direct puncture tunnel method. We consider the direct puncture tunnel method to be a simple, effective, and safe way to establish the retroperitoneal cavity.