VCOM Louisiana Research Day Program Book 2024

Clinical Research

Kristen McDonald, OMS-III; Rebecca Peters, OMS-III; Saahir Mukherjee, OMS-III; Jacob Stuntz, OMS-III; Anne-Marie Ogden, OMS-II; Emma Barham, OMS-II; Morgan Minard, OMS-II; Sarah North, OMS-II VCOM-Louisiana 27 THE ANATOMICAL VARIATIONS WITHIN THE RETROPERITONEAL SPACE: A COMPREHENSIVE EXPLORATION OF EMBRYOLOGY, MUSCULATURE, VASCULATURE, AND THE LUMBAR PLEXUS

Background: The retroperitoneal space is a critical anatomical region comprising vital organs and intricate structures relevant to spinal procedures. The retroperitoneum has been characterized in many textbooks, however, there is a paucity in the literature regarding the utilization of this space in the surgical management of spinal abnormalities. Furthermore, there is much to be characterized in terms of anatomical variation in the retroperitoneal space. This research paper examines multiple aspects of the retroperitoneal space with a focus on the anatomical variations in hopes of providing a better understanding of the surgical approach to lateral lumbar interbody fusion. Objective: Our objective was to conduct a thorough literature review on the retroperitoneal space. To better characterize the retroperitoneal space for use in surgical techniques, we combined our findings related to cadaveric and clinical samples. Furthermore, our objectives were to characterize the retroperitoneal space within our own dissections for future research on the utilization of this space. Methods: For the study, we used five cadavers donated from the Texas Willed Body Program to VCOM in Louisiana. Four of our sample

cadavers were dissected in the supine position while one dissection was performed in the prone position. The dissections were performed by a neurosurgeon and a small team of medical students throughout the 2022-2023 academic year. Dissections were performed on the left side of each of the cadavers as the right leg was removed for exposure of the lumbar and sacral plexus. Our dissection field primarily focused on the L1-L4 region, as our particular interest is the potential for the utilization of the retroperitoneal space as a potential route for a lateral approach to lumbar fusion surgery. Throughout the dissections, described the pathways as well as measured the lengths of each nerve of the lumbar plexus, the vena cava, left common iliac vein and artery, left iliofemoral vein, left lumbar vein and artery, left lumbar ascending vein, left renal vein and artery, left gonadal vein and artery, and the aorta. We also detailed the relationships amongst the noted structures. Results: Our results included a thorough literature review on the anatomy, embryological development, and anatomical variants of the structures within the retroperitoneal space. The nerves of the lumbar plexus showed common variations including potential absence of the iliohypogastric nerve and the abnormally low exit of the lateral femoral cutaneous nerve from

the supero-posterior vertebral body of L4. The femoral nerve and obturator nerve have been shown to fluctuate in their degrees of variation. Major retroperitoneal vessels include branches of the descending abdominal aorta and venous vessels arising from the Inferior Vena Cava. Major variations of these vessels in the studied cadaveric specimens were not appreciated; however, common vessel pathways were recognized. Although there was mild variation in the width and length of certain vessels among the five cadavers, the clinical relevance of such variation warrants further investigation. Conclusions: This dissectional approach to research provides a comprehensive overview of anatomical variations within the retroperitoneal space spanning embryological development, musculature, vasculature, and the lumbar plexus. The insights gained through this study contribute to a deeper understanding of the retroperitoneal space offering valuable knowledge for clinicians, anatomists, and researchers.

43 2024 Via Research Recognition Day