A prosthesis (10; 200; 400; 520), comprising: a tubular graft main body (20; 220) including a sidewall (25; 225) extending between an inflow end (27; 227; 427; 534) and an outflow end (28; 228; 428; 532), and a main lumen (26; 226; 530) extending between the outflow end (28; 228; 428; 532) and inflow end (27; 227; 427; 534) about a graft longitudinal axis, the tubular graft main body (20; 220) including an inflow end segment (20A; 220A), an outflow end segment (20C; 220C), and an intermediate segment (20B; 220B) interconnecting the inflow end segment (20A; 220A) and the outflow end segment (20C; 220C); a trough (50; 250; 450; 540) of graft material extending radially inwardly from the sidewall; and a tubular graft branch (60; 260; 460; 525) having a branch lumen extending therein, the graft branch (60; 260; 460; 525) extending from the trough (50; 250; 450; 540) of graft material within the main lumen (26; 226; 530) in a helical pattern in a direction away from the inflow end (27; 227; 427; 534) of the graft main body in a retrograde configuration, wherein the trough (50; 250; 450; 540), the branch lumen , and the main lumen (26; 226; 530) are in fluid communication; wherein: 1) the graft branch (60; 260; 460; 525), the trough (50; 250; 450; 540), and the graft main body (20; 220) are integrally comprised of a common graft material, wherein the trough (50; 250; 450; 540) and the graft branch (60; 260; 460; 525) are in an inverted relationship relative to the graft main body; and/or 2) the trough has a proximal axial side (55A; 255A) and a distal axial side (55B; 255B), and at least a portion (U) of the proximal axial side is unobstructed from stitching and/or trough frames . a tubular graft main body (20; 220) including a sidewall (25; 225) extending between an inflow end (27; 227; 427; 534) and an outflow end (28; 228; 428; 532), and a main lumen (26; 226; 530) extending between the outflow end (28; 228; 428; 532) and inflow end (27; 227; 427; 534) about a graft longitudinal axis, the tubular graft main body (20; 220) including an inflow end segment (20A; 220A), an outflow end segment (20C; 220C), and an intermediate segment (20B; 220B) interconnecting the inflow end segment (20A; 220A) and the outflow end segment (20C; 220C); a trough (50; 250; 450; 540) of graft material extending radially inwardly from the sidewall; and a tubular graft branch (60; 260; 460; 525) having a branch lumen extending therein, the graft branch (60; 260; 460; 525) extending from the trough (50; 250; 450; 540) of graft material within the main lumen (26; 226; 530) in a helical pattern in a direction away from the inflow end (27; 227; 427; 534) of the graft main body in a retrograde configuration, wherein the trough (50; 250; 450; 540), the branch lumen , and the main lumen (26; 226; 530) are in fluid communication; wherein: 1) the graft branch (60; 260; 460; 525), the trough (50; 250; 450; 540), and the graft main body (20; 220) are integrally comprised of a common graft material, wherein the trough (50; 250; 450; 540) and the graft branch (60; 260; 460; 525) are in an inverted relationship relative to the graft main body; and/or 2) the trough has a proximal axial side (55A; 255A) and a distal axial side (55B; 255B), and at least a portion (U) of the proximal axial side is unobstructed from stitching and/or trough frames . 1) the graft branch (60; 260; 460; 525), the trough (50; 250; 450; 540), and the graft main body (20; 220) are integrally comprised of a common graft material, wherein the trough (50; 250; 450; 540) and the graft branch (60; 260; 460; 525) are in an inverted relationship relative to the graft main body; and/or 2) the trough has a proximal axial side (55A; 255A) and a distal axial side (55B; 255B), and at least a portion (U) of the proximal axial side is unobstructed from stitching and/or trough frames . <EOS>