An endovascular delivery system, comprising: a prosthesis comprising a main tubular body having an open proximal end and opposed open ipsilateral and contralateral legs (126, 128); an elongate outer tubular sheath having an open lumen and opposed proximal and distal ends with a medial portion therein between; an elongate inner tubular member slidably disposed within the open lumen of the outer tubular sheath; wherein the distal end of the outer tubular sheath being slidably disposed past and beyond the distal end of the inner tubular member to define a prosthesis delivery state and slidably retractable to the medial portion of the inner tubular member to define a prosthesis unsheathed state; an elongate guidewire slidably disposed within the inner tubular member and extending from the handle assembly, through the ipsilateral leg of the prosthesis and through the main tubular body of the prosthesis and extending past the open of the main tubular body in the prosthesis delivery state; and characterized in that the endovascular delivery system comprises an inflatable occlusion balloon disposed on a portion of the elongate guidewire extending past the open end of the main tubular body; wherein the elongate guidewire comprises a hollow portion such that the inflatable occlusion balloon is in fluid communication with a balloon inflation material; wherein the endovascular delivery system has an overall outer diameter from about 3.3 mm (10 French) to about 4.7 mm (14 French) or less than 3.3 mm (10 French); wherein the inflatable occlusion balloon has a wall having a thickness from about 0.01 mm (0.0005 inches) to about 0.08 mm (0.003 inches); and wherein the elongate guidewire an outer diameter from about 0.64 mm (0.025 inches) to about 1.1 mm (0.045 inches). a prosthesis comprising a main tubular body having an open proximal end and opposed open ipsilateral and contralateral legs (126, 128); an elongate outer tubular sheath having an open lumen and opposed proximal and distal ends with a medial portion therein between; an elongate inner tubular member slidably disposed within the open lumen of the outer tubular sheath; wherein the distal end of the outer tubular sheath being slidably disposed past and beyond the distal end of the inner tubular member to define a prosthesis delivery state and slidably retractable to the medial portion of the inner tubular member to define a prosthesis unsheathed state; an elongate guidewire slidably disposed within the inner tubular member and extending from the handle assembly, through the ipsilateral leg of the prosthesis and through the main tubular body of the prosthesis and extending past the open of the main tubular body in the prosthesis delivery state; and characterized in that the endovascular delivery system comprises an inflatable occlusion balloon disposed on a portion of the elongate guidewire extending past the open end of the main tubular body; wherein the elongate guidewire comprises a hollow portion such that the inflatable occlusion balloon is in fluid communication with a balloon inflation material; wherein the endovascular delivery system has an overall outer diameter from about 3.3 mm (10 French) to about 4.7 mm (14 French) or less than 3.3 mm (10 French); wherein the inflatable occlusion balloon has a wall having a thickness from about 0.01 mm (0.0005 inches) to about 0.08 mm (0.003 inches); and wherein the elongate guidewire an outer diameter from about 0.64 mm (0.025 inches) to about 1.1 mm (0.045 inches).