[Is posterior lumbar epidural space partitioned?].

Area of Science:

• Anatomy
• Radiology
• Anesthesiology

Background:

• The anatomy of the posterior lumbar epidural space (PLES) is of interest to anatomists, surgeons, radiologists, and anesthesiologists.
• Previous studies suggest a medial partition in the PLES, observed via epidurography and intraoperative findings.
• Discrepant descriptions arise from different specialist perspectives on PLES anatomy.

Purpose of the Study:

• To clarify the anatomical reality of a medial partition within the posterior lumbar epidural space.
• To reconcile differing observations of the PLES based on various anatomical and imaging techniques.
• To investigate the role of fatty tissue and dural folds in PLES morphology.

Main Methods:

• Review of existing anatomical studies, including epidurography, CT scans, laminectomy observations, and cadaveric resin casts.
• Analysis of epiduroscopy findings in cadavers.
• Consideration of histological data on PLES composition.

Main Results:

• Previous imaging and surgical observations suggested a medial partition (plica mediana dorsalis durae matris) in the PLES.
• Experimental attempts to confirm this partition using resin casts yielded unconvincing results.
• Epiduroscopy in cadavers suggested the presence of the PMD and a connective tissue band, but technical limitations affected image quality.

Conclusions:

• The PLES is a virtual space primarily filled with fatty tissue, which can be compressed or altered.
• Observed PLES partitions may be artifacts of injected substances (contrast or anesthetic) deforming the fatty tissue and dura.
• Histological evidence suggests fatty tissue, not a rigid partition, accounts for the variable PLES morphology seen in imaging and surgery.