Clinical Anatomy and Possible Clinical Significance of the Intervertebral Vein in the Lumbar Intervertebral Foramina

Abstract

Background: The detailed structure of the lumbar intervertebral foramina has been wellstudied. Nevertheless, detailed descriptions of branches of the intervertebral vein (IV) through the lumbar intervertebral foramina are lacking. Objectives: This study aimed to provide an anatomical basis for invasive treatment targeting the branches of the IV using an approach through the lumbar intervertebral foramina, particularly for the purposes of transforaminal epidural steroid injection. Study Design: This research involved a dissection-based study of 10 embalmed human cadavers. Setting: The research took place at The Third Affiliated Hospital of Southern Medical University. Methods: One hundred lumbar intervertebral foramina from 10 embalmed cadavers were studied. Branches of the IV in the intervertebral foramina were observed. The length and diameter of the veins were measured using a Vernier caliper. Results: At a rate of 100%, branches of the IV were observed in the 100 lumbar foramina examined in our study. The following 4 types of branches of the IV were routinely found: Type I in 27 (27%) of the IV foramina, in which a superior branch of the IV ran along the inferior margin of the vertebral pedicle; Type II in 18 (18%) of the intervertebral foramina, in which an inferior branch of the IV ran along the superior margin of the inferior vertebral pedicle; Type III in 41 (41%) of the intervertebral foramina, in which the IV was divided into a superior and inferior branch; and Type IV in 14 (14%) of the intervertebral foramina, in which the IV was divided into 2 superior branches and an inferior branch. Limitations: The greatest weakness of this study is that it lacks actual clinical verification. Future clinical trials are expected to contribute more objective data concerning the IV branches. Due to the relative changes in vascular position during dissection, the relevant data warrant improvement. Conclusions: The lumbar IVs are an important part of the anatomical structure of the intervertebral foramina. Adequate knowledge of the IV may be of clinical importance to physicians performing transforaminal epidural steroid injection. Key words: Clinical anatomy, intervertebral veins, lumbar vertebra, Kambin’s triangle, safe triangle, intervertebral foramina, vertebral venous system, inadvertent injection, transforaminal epidural steroid injection