Abstract
BACKGROUND: Radiologists currently accept the concept of "interfascial plane (IFP)" to understand retroperitoneal anatomy, replacing Meyers' classic tricompartmental theory. Despite much research on retroperitoneal anatomy, its anatomical structure, embryonic origin and developmental process still require further exploration to guide the optimization of surgical process. This study aims to explore the anatomical basis of IFP related to laparoscopic upper retroperitoneal surgery (LURS) and to compare the clinical outcomes of trans-interfascial plane procedures for LURS (TIFP-LURS) with conventional LURS (Con-LURS). METHODS: The study consisted of two parts: cadaveric and clinical study. The cadaveric study involved dissecting and observing the retroperitoneal fasciae and IFP in 32 cadavers using gross anatomical and histological methods. This retrospective clinical study compared the perioperative data and complications of 229 patients who underwent TIFP-LURS and 121 patients who underwent Con-LURS for upper retroperitoneal lesions at our center. RESULTS: The cadaveric study revealed that the retroperitoneal space was composed of multilaminar fasciae that formed potential bloodless spaces among them, that could be used as surgical landmarks and operating planes. The clinical study showed that TIFP-LURS had a significantly less estimated blood loss, lower intraoperative complication rate, lower postoperative complication rate, shorter hospital-stay and lower long-term postoperative complications rate than Con-LURS. Multivariate analysis indicated that the TIFP procedure was an independent protective factor for decreasing the risk of postoperative complications. CONCLUSIONS: The IFP are potential avascular spaces that can be used during laparoscopic surgery, and TIFP-LURS is a novel surgical approach that can improve the safety and efficacy of laparoscopic surgery for upper retroperitoneal lesions.