Endoluminal prosthetic assemblies, and associated systems and methods for percutaneous repair of a vascular tissue defect

A method for repairing a target tissue defect in a blood vessel of a patient, the method comprising:

• positioning a branch assembly in a radially-contracted configuration within a region of the blood vessel having the target tissue defect, wherein a distal segment of the branch assembly is disposed within a branch vessel and a proximal segment of the branch assembly is disposed within the blood vessel, and wherein the branch assembly includes,
• an outer branch stent-graft having an inflow region at the proximal segment;
• and
• an inner support structure configured to be at least partially disposed within the inflow region at the proximal segment of the branch assembly;
• positioning an exclusion structure in the blood vessel, wherein at least a proximal portion of the exclusion structure is adjacent to the proximal segment of the branch assembly in the blood vessel, and wherein a central portion of the exclusion structure is aligned with the target tissue defect in the blood vessel;
• expanding the exclusion structure in the blood vessel such that the central portion bypasses the target tissue defect in the blood vessel;
• expanding the branch assembly to a deployed configuration, wherein the proximal portion of the exclusion structure at least partially deforms the inflow region of the outer branch stent-graft without substantially deforming the inner support structure
• wherein the outer branch stent-graft and the support structure are both disposed in a first delivery catheter prior to deployment, wherein expanding the branch assembly to a deployed configuration further includes:
• deploying the outer branch stent-graft from the first delivery catheter,
• after deploying the outer branch stent-graft, advancing the first delivery catheter such that the support structure is at least partially disposed within the outer branch stent-graft, and
• after advancing the first delivery catheter, deploying the support structure at least partially within the outer branch stent-graft.