Looking beyond the gunsight: A potential bailout technique for arterial and venous recanalization

The "gunsight approach" was initially described as the use of overlapping snares and through-and-through puncture of the portal vein and inferior vena cava for the creation of a transcaval portosystemic shunt. This technique can be adapted for the creation of an extra-anatomic channel between any 2 locations where snares can be deployed. We explain the technique, discuss finer technical points, and describe 2 cases where refractory vascular occlusions are crossed using this technique. The first case involves an extensively calcified femoral arterial chronic total occlusion where subintimal tracking past the occlusion is achieved, but luminal re-entry is hampered by dense calcific plaque refractory to multiple re-entry devices. The second case involves a chronic venous occlusion along the femoral vein with loss of in-line flow due to prior stenting. In both cases, the gunsight technique was successfully used as a bailout option after standard recanalization techniques were unsuccessful.