Background and Objectives: The celiac plexus is a dense autonomic network surrounding the celiac trunk. To block this plexus, the celiac trunk is a landmark for needle placement. Needles inserted at a distance from the midline, "walking off" the vertebra, may penetrate surrounding organs. We reviewed 200 computed tomography images to investigate the celiac trunk topography relating to the block.

Methods: Two hundred computed tomography images across the celiac trunk were displayed. The celiac emergence level and celiac-aortic-vertebral anatomies were examined. On each image, 2 needle trajectories imitating walking-off technique were placed tangential to the vertebral body passing through the crus of the diaphragm on both sides: L-9s and L-4.5s (9 and 4.5 cm from the midline, respectively). The vital organs traversed by these lines were noted and analyzed.

Results: Celiac emergence levels: T_11-12, 6.5%; T₁₂, 34%; T₁₂−L₁, 31%; L₁, 28.5%. Aortic locations: 70% were anterior-left to and 29% were anterior-middle to the vertebra. Celiac runoffs: 63.5% from the aorta anterolaterally on the left, 36% from the midportion. Celiac-aortic-vertebral correlations showed a various distribution in groups; 88% L-9s and 64% L-4.5s on the right side, and 96% L-9s and 88% L-4.5s on the left side traversed different vital organs with various frequencies.

Conclusions: The celiac trunk anatomy varies. Blocking needles walking off the vertebra from a fixed distance frequently traverse vital organs. Previewing celiac-aortic-vertebral topography with a simulating block on individual patient's computed tomography (CT) image for accordant needle placement subsequently is warranted.