Retroperitoneal anatomy and avascular spaces for pelvic surgery: Cadaveric dissection atlas.

This paper presents a comprehensive cadaveric dissection atlas detailing the retroperitoneal anatomy essential to advanced pelvic surgery. Developed by a multidisciplinary team of anatomists, gynecologists, and gynecologic oncologists, the study provides a systematic, layer-by-layer guide for navigating the pelvic avascular spaces. It details five critical surgical corridors: the presacral (retrorectal) space, the pararectal space (divided into the Latzko and Okabayashi compartments), the paravesical space (medial and lateral compartments), the prevesical (retropubic/Retzius) space, and the medial psoas space (laterovascular plane). This atlas emphasizes the use of reliable landmarks, such as the sacral promontory, the obliterated umbilical artery, and the ureter, to define anatomical boundaries and ensure safe surgical practice. The primary objective is to maintain adequate exposure after retroperitoneal entry and to perform layer-by-layer surgical dissection to identify critical anatomical structures. The superior hypogastric plexus; hypogastric nerve; pelvic splanchnic nerves; inferior hypogastric plexus with its vesical and rectal branches; the internal iliac artery with its posterior and anterior trunk branches (including the superior gluteal, iliolumbar, lateral sacral, uterine, inferior gluteal, pudendal, obturator, middle rectal, and inferior and superior vesical arteries, and the obliterated umbilical artery); the external iliac artery; and the corresponding internal and external iliac veins were discussed. Additionally, the somatic nerves, obturator nerve, lumbosacral trunk, sacral nerves, sciatic nerve, genitofemoral nerve, and femoral nerve were reviewed. The parietal fascial planes, pubocervical fascial structure, and visceral compartments were evaluated as part of the whole. Respecting fascial planes-particularly the presacral fascia-is mandatory to avoid catastrophic hemorrhage and autonomic nerve injury. These spaces serve as the "neurovascular roadmap" for complex procedures, including radical hysterectomy, nerve-sparing pelvic surgery, pelvic lymphadenectomy, and hemorrhage control. Mastery of these interconnected retroperitoneal compartments facilitates a transition from organ-based to space-oriented surgery, significantly reducing morbidity while maintaining oncologic radicality.