A system for the delivery and deployment of an endovascular graft comprising: a. a delivery device having a proximal end portion to travel through a vessel lumen to a deployment site and a distal manipulation section, the delivery device comprising: i. a pusher catheter having a proximal end portion and a distal end portion and at least one lumen extending at least partially between the proximal and distal end portions; ii. a guide wire cannula having a proximal end portion and a distal end portion and extending longitudinally within a lumen of the pusher catheter; b. a stent graft carried on the delivery device at the proximal end portion, the stent graft comprising: i. a main tubular body of a biocompatible graft material having a proximal end and a distal end defining a main lumen therebetween, ii. a side branch extending from the main tubular body, the side branch having a lumen extending therethrough and being in fluid communication with the main lumen at the proximal end portion of the side branch, c. an auxiliary guide wire extending proximally within a lumen of the pusher catheter and into the distal end of the main tubular body of the stent graft, the auxiliary guide wire further extending distally through at least a portion of the lumen of the side branch and through a lumen of the pusher catheter, and d. a pre-loaded auxiliary sheath comprising a proximal end portion and a distal end portion and a lumen extending therebetween, wherein the system is configured such that the auxiliary sheath comprises a first position wherein the sheath proximal end portion is located distal to the distal end portion of the main graft tubular body and a second position wherein the sheath is advanced over the auxiliary guide wire such that the proximal end portion of the sheath enters the lumen of the side branch by way of a proximal end portion of the side branch and extends at least partially into the lumen of the side branch. a. a delivery device having a proximal end portion to travel through a vessel lumen to a deployment site and a distal manipulation section, the delivery device comprising: i. a pusher catheter having a proximal end portion and a distal end portion and at least one lumen extending at least partially between the proximal and distal end portions; ii. a guide wire cannula having a proximal end portion and a distal end portion and extending longitudinally within a lumen of the pusher catheter; i. a pusher catheter having a proximal end portion and a distal end portion and at least one lumen extending at least partially between the proximal and distal end portions; ii. a guide wire cannula having a proximal end portion and a distal end portion and extending longitudinally within a lumen of the pusher catheter; b. a stent graft carried on the delivery device at the proximal end portion, the stent graft comprising: i. a main tubular body of a biocompatible graft material having a proximal end and a distal end defining a main lumen therebetween, ii. a side branch extending from the main tubular body, the side branch having a lumen extending therethrough and being in fluid communication with the main lumen at the proximal end portion of the side branch, i. a main tubular body of a biocompatible graft material having a proximal end and a distal end defining a main lumen therebetween, ii. a side branch extending from the main tubular body, the side branch having a lumen extending therethrough and being in fluid communication with the main lumen at the proximal end portion of the side branch, c. an auxiliary guide wire extending proximally within a lumen of the pusher catheter and into the distal end of the main tubular body of the stent graft, the auxiliary guide wire further extending distally through at least a portion of the lumen of the side branch and through a lumen of the pusher catheter, and d. a pre-loaded auxiliary sheath comprising a proximal end portion and a distal end portion and a lumen extending therebetween, wherein the system is configured such that the auxiliary sheath comprises a first position wherein the sheath proximal end portion is located distal to the distal end portion of the main graft tubular body and a second position wherein the sheath is advanced over the auxiliary guide wire such that the proximal end portion of the sheath enters the lumen of the side branch by way of a proximal end portion of the side branch and extends at least partially into the lumen of the side branch.