Purpose: To describe planning and a technique for fenestrated endovascular repair of a large Crawford type IV thoracoabdominal aortic aneurysm after previous 2-fenestration endovascular aneurysm repair (FEVAR). Technique: The first FEVAR procedure performed at another center implanted a standard Zenith device with 2 fenestrations and 1 scallop for a juxtarenal abdominal aortic aneurysm. The diameter of the Crawford type IV thoracoabdominal aortic aneurysm had progressed from 68 to 75 mm within a year after the FEVAR. Since the celiac trunk was already occluded, a 3-fenestration 22-×172-mm stent-graft was chosen to extend the existing stent-graft further proximally. A tapered 38/22-×179-mm Zenith custom-made device was designed for the thoracic component. The technique addresses several issues that arise during a FEVAR-in-FEVAR case, such as the orientation of the new stent-graft and its fenestrations, the absence of space between the 2 devices for maneuvers, and the difficulty in catheterizing target vessels with existing bridging stents, for which a bailout “snare-ride” maneuver is described. Conclusion: FEVAR after previous FEVAR is a feasible and efficient treatment option. The modified “snare-ride” technique can be used to catheterize target vessels in the absence of an Indy snare.