A vascular occlusion catheter (10, 110, 210) for at least partial occlusion of a target vessel having an internal vessel wall, the vascular occlusion catheter (10, 110, 210) system comprising: a proximal outer shaft (22, 122, 222); a distal outer shaft (18, 118, 218) distally terminating with an atraumatic tip (20, 120, 220); an occlusion balloon (16,116,216) connected to the proximal outer shaft (22, 122, 222) at a proximal neck (16a, 216a) and the distal outer shaft (18, 118, 218) at a distal neck (16b, 216b); the proximal outer shaft (22, 122, 222) having a first internal lumen (123, 223) and a second internal lumen (22c, 22c', 122c, 222c), the first internal lumen (123, 223) being in fluid communication with the occlusion balloon (16, 116, 216); the distal outer shaft (18, 118, 218) having a distal internal lumen; a hypotube (12, 112, 212) having an internal hypotube lumen (12a, 112a), the hypotube (12, 112, 212) extending through the first internal lumen (123, 223), through the occlusion balloon (16, 116, 216) and into communication with the distal internal lumen, the hypotube (12, 112, 212) operating as the primary load-bearing chassis of the vascular occlusion catheter (10, 110, 210); a first window (22a, 222a) formed in the proximal outer shaft (22, 122, 222); a proximal sensor (26, 126, 226) being positioned within the second internal lumen (22c, 22c', 122c, 222c) facing the first window (22a, 222a); a second window (18a, 218a) formed in distal outer shaft (18, 118, 218); a distal sensor (28, 128, 228) being positioned within the distal internal lumen facing the second window (18a, 218a); and a display hub (34, 234) positioned along the proximal outer shaft (22, 122, 222), wherein the second internal lumen (22c, 22c', 122c, 222c) and the hypotube (12, 112, 212) extend into the display hub (34, 234), the display hub (34, 234) being electrically connected with the proximal sensor (26, 126, 226) via the second internal lumen (22c, 22c', 122c, 222c), and the display hub (34, 234) being electrically connected with the distal sensor (28, 128, 228) via the internal hypotube lumen (12a, 112a) and the distal internal lumen; wherein the occlusion balloon (16, 116, 216), the proximal outer shaft (22, 122, 222) and the distal outer shaft (18, 118, 218) have a greatest outer diameter of 2.3 mm (seven French (7 Fr)) or less in an uninflated condition. a proximal outer shaft (22, 122, 222); a distal outer shaft (18, 118, 218) distally terminating with an atraumatic tip (20, 120, 220); an occlusion balloon (16,116,216) connected to the proximal outer shaft (22, 122, 222) at a proximal neck (16a, 216a) and the distal outer shaft (18, 118, 218) at a distal neck (16b, 216b); the proximal outer shaft (22, 122, 222) having a first internal lumen (123, 223) and a second internal lumen (22c, 22c', 122c, 222c), the first internal lumen (123, 223) being in fluid communication with the occlusion balloon (16, 116, 216); the distal outer shaft (18, 118, 218) having a distal internal lumen; a hypotube (12, 112, 212) having an internal hypotube lumen (12a, 112a), the hypotube (12, 112, 212) extending through the first internal lumen (123, 223), through the occlusion balloon (16, 116, 216) and into communication with the distal internal lumen, the hypotube (12, 112, 212) operating as the primary load-bearing chassis of the vascular occlusion catheter (10, 110, 210); a first window (22a, 222a) formed in the proximal outer shaft (22, 122, 222); a proximal sensor (26, 126, 226) being positioned within the second internal lumen (22c, 22c', 122c, 222c) facing the first window (22a, 222a); a second window (18a, 218a) formed in distal outer shaft (18, 118, 218); a distal sensor (28, 128, 228) being positioned within the distal internal lumen facing the second window (18a, 218a); and a display hub (34, 234) positioned along the proximal outer shaft (22, 122, 222), wherein the second internal lumen (22c, 22c', 122c, 222c) and the hypotube (12, 112, 212) extend into the display hub (34, 234), the display hub (34, 234) being electrically connected with the proximal sensor (26, 126, 226) via the second internal lumen (22c, 22c', 122c, 222c), and the display hub (34, 234) being electrically connected with the distal sensor (28, 128, 228) via the internal hypotube lumen (12a, 112a) and the distal internal lumen; wherein the occlusion balloon (16, 116, 216), the proximal outer shaft (22, 122, 222) and the distal outer shaft (18, 118, 218) have a greatest outer diameter of 2.3 mm (seven French (7 Fr)) or less in an uninflated condition.