Vaginal Dissection of the Rectovaginal and Pararectal Spaces: Surgical Anatomy and Key Landmarks

INTRODUCTION: A precise understanding of the avascular pelvic spaces is fundamental to safe and successful gynecologic surgery. These anatomical planes provide critical boundaries that enable deep dissection while minimizing the risk of neurovascular or visceral injury. The rectovaginal and pararectal spaces, located in the posterior vaginal compartment, are commonly accessed during complex procedures for prolapse, endometriosis, and resection of benign or malignant masses. Transvaginal entry into these spaces can be technically demanding due to limited visualization, scarring from prior surgeries or childbirth, and distortion from advanced prolapse. To date, there are limited surgical videos that provide a comprehensive, step-by-step dissection of both the rectovaginal and pararectal spaces via a transvaginal approach. OBJECTIVE: The objectives of this video are to: (1) demonstrate a detailed, complete dissection of the rectovaginal and pararectal spaces via a vaginal approach and (2) highlight key anatomical landmarks, spatial boundaries, and critical neurovascular and visceral structures to avoid during surgery. METHODS: Using internationally accepted anatomic terminology, this video presents a stepwise transvaginal dissection of the rectovaginal and pararectal spaces. The technique emphasizes full-thickness posterior vaginal wall dissection using traction, counter-traction, and sharp dissection. A V-shaped perineal skin incision initiates access to the rectovaginal space, followed by separation of the vaginal mucosa from the perineal body, rectum, and any obstetric scar tissue. This approach allows safe entry into the rectovaginal space and peritoneal cavity for procedures such as enterocele repair, rectovaginal fistula repair, uterosacral ligament suspension, and mass excision. With stable retraction and combined sharp/blunt dissection, the rectovaginal space is extended laterally beyond the rectal pillars—while avoiding branches of the middle rectal arteries—to access the pararectal space. Key landmarks, including the iliococcygeus muscle, coccygeus-sacrospinous ligament (C-SSL), and ischial spine, are identified to guide dissection and orient neurovascular anatomy. A full view of the C-SSL is demonstrated, offering a novel perspective to facilitate safe suture placement with adequate margins from the rectum and awareness of surrounding neurovascular structures. RESULTS: This video demonstrates clear exposure and access to the rectovaginal and pararectal spaces via a transvaginal approach. Direct visualization of these spaces enables identification of key anatomical landmarks critical for guiding safe and effective dissection. The spatial relationships between these compartments, the pelvic floor musculature, and adjacent viscera are clearly illustrated. Additionally, the theoretical locations of important structures—including the middle rectal vessels, ureter, cardinal ligament, sacral nerves, inferior gluteal vessels, and the pudendal neurovascular bundle—are highlighted to enhance surgical orientation and safety. CONCLUSIONS: This video highlights essential anatomical and surgical principles through a detailed dissection, demonstrating the progression from perineal incision to full-thickness posterior vaginal wall dissection and entry into the rectovaginal and pararectal spaces. Key anatomical landmarks and critical structures are clearly visualized, with practical tips and techniques provided to support the safe surgical execution. By reinforcing foundational anatomical knowledge and showcasing evidence-based surgical practices, this video serves as a valuable educational resource for both novice and experienced pelvic surgeons. Importantly, it supports ongoing efforts to maintain and advance vaginal surgical skills necessary for gynecologic surgeons.