Examination of Spinal Canal Anatomy with MRI Measurements in Lomber Disc Herniation Patients: An Anesthesiologist Viewpoint

BACKGROUND AND AIM: The aim of this study is to investigate the magnetic resonance imaging (MRI) of patients with lumbar disc herniation (LDH) to identify the challenges associated with neuraxial anesthesia. MATERIALS AND METHODS: The MRI images in the supine position of 203 patients admitted to hospital with complaints of lower back pain were studied. Medial sagittal slices of the lumbar spine were imaged from L1 to S1. LDH is classified as either bulging, extrusion, or protrusion. RESULTS: For this study, 83 males and 120 females with a mean age of 43.18 ± 14.68 years were recruited. The highest herniation level was observed at L4–L5 in 145 (71.4%) patients: 76 instances of disc bulging (37.4%), 56 instances of extrusion (27.6%), and 13 instances of protrusion (6.4%). The longest distance between the skin and spinal cord was 60.06 ± 1.61 mm at L5–S1; the longest distance at width of the epidural space was 6.09 ± 1.95 mm at L3–L4. According to the disc herniation groups, no significant differences were found between the skin-to-dura distance, width of the epidural space, and depth of skin level to spinous process (P > 0.05). Moreover, the anterior dura to cord distances was significantly different from normal patients (P < 0.05). Indeed, there was a statistically weak and negative correlation between both the length and age of the lumbar spinal canal (P < 0.05, r = −0.295). CONCLUSIONS: Lumbar disc pathologies can cause anatomical derangements in the spinal canal, which may cause neurologic deficits by neuraxial blockade.