Computerized tomographic anatomic relationships of the thoracic paravertebral space

Area of Science:

• Anesthesiology
• Thoracic Surgery
• Radiology

Background:

• Paravertebral blockade is a technique used for analgesia and anesthesia.
• Various insertion points lateral to the midline are recommended for paravertebral blockade.
• The depth to the pleura varies depending on the insertion point and patient anatomy.

Purpose of the Study:

• To evaluate the hypothesis that an insertion point at the tip of the transverse process offers a superficial and consistent depth to the pleura.
• To determine if patient anthropomorphic indices can reliably predict the depth to the pleura for a given insertion point.

Main Methods:

• Retrospective observational study of 42 adult patients.
• Analysis of computerized tomography scans.
• Correlation of patient anthropomorphic indices (BMI, weight, height, body surface area) with skin and transverse process-to-pleura depths at T4, 25 mm lateral to midline and at the transverse process tip.

Main Results:

• The depth to the pleura was significantly greater and more variable at 25 mm lateral to the midline compared to the transverse process tip (21 mm vs 12 mm).
• Significant correlations (r>0.8) were found between anthropomorphic indices and depths to the pleura and transverse process.
• Prediction bands around regression lines were too broad for clinical utility.

Conclusions:

• An insertion point at the tip of the transverse process may offer a safer and more effective approach for paravertebral blockade.
• Patient morphometric profiles are not reliable predictors of the depth to the pleura for paravertebral blockade.