A method includes deploying a bloused stent-graft into a main vessel such that a bloused section of the bloused stent-graft covers a branch vessel emanating from the main vessel. The bloused section includes loose graft cloth. A pressure differential between the main vessel and the branch vessel causes the bloused section to be forced into an ostium of the branch vessel creating a pocket aligned with the branch vessel. A distal tip of a puncture device is located in the pocket and thus aligned with the branch vessel. An outward force is applied to the puncture device to cause the distal tip of the puncture device to fenestrate the bloused section thus creating a collateral opening in the bloused section precisely aligned with the branch vessel.