A needle-based contrast injection technique to establish retrograde popliteal access when no patent puncture target is visible

Long blunt-type chronic total occlusions (CTOs) originating from the superficial femoral artery ostium and extending to the below-the-knee arteries pose two linked technical challenges: resistant antegrade entry into the ostial cap and the need to secure distal outflow. Retrograde popliteal access can provide a favorable counter-approach, but puncture may be impossible when the popliteal artery itself is occluded and no definite sonographic or angiographic target is visible. We describe a patient with chronic limb-threatening ischemia and a continuous occlusion from the superficial femoral artery ostium to the below-the-knee arteries. Because conventional retrograde puncture failed to provide a passable guidewire route, contrast medium was injected directly through the puncture needle after ultrasound confirmation that the needle tip was within the occluded vessel. This maneuver created and opacified an intralesional or subintimal space, permitting guidewire advancement and retrograde sheath insertion. The newly established retrograde access enabled intravascular ultrasound-guided CTO crossing, balloon-facilitated externalization, redirection toward a true-lumen-oriented course, and subsequent antegrade wiring to below-the-knee outflow. Complete inline revascularization was achieved. Direct needle contrast injection may be a useful bailout access technique in selected complex femoropopliteal CTO interventions when a retrograde approach is required but conventional popliteal puncture is not feasible.