Which breathing maneuver helps distinguish median arcuate ligament compression of the celiac artery from intrinsic disease when measuring PSV?

• A. Deep inspiration
• B. End expiration
• C. Valsalva maneuver
• D. Standing breath-hold

Answer: (A)

Dynamic, respiration-dependent compression underlies this scenario. The median arcuate ligament can squeeze the proximal celiac artery, and this extrinsic compression is relieved with deep inspiration as the diaphragm descends and the ligament moves away from the vessel. Measuring peak systolic velocity during deep inspiration will typically show a lowering of velocity if MAL compression is the cause. If intrinsic disease is present, the high velocity persists regardless of breath-hold or inspiratory effort. Therefore, deep inspiration is the maneuver that best distinguishes MAL-related compression from intrinsic disease when evaluating PSV.