A sheath structure configured for cannulating an anatomical vessel, the sheath structure comprising: a first tube having an elongate length, a distal end, a proximal end, and a lumen (110, 210) therebetween for channeling a fluid, the first tube including: a distal portion coupled to the distal end and configured for receiving an endovascular or transcatheter device; a valve portion disposed near or at the distal end, the valve portion including at least one valve and configured for preventing backflow of a first portion of the fluid out of the distal end; and a first segment configured to entirely reside within the vessel when the vessel is cannulated, the first segment comprising: a first lumen therein fluidically coupled to the lumen of the first tube a proximal opening configured for receiving the fluid from a pumping source and channeling the fluid into the first lumen; and a set of fenestrations disposed distal to the proximal opening and fluidically coupled thereto, the set of fenestrations configured for distally outputting or discharging a second portion of the fluid into the vessel, characterised in that the set of fenestrations is arranged around a portion of the periphery of the first segment such that a plane through the fenestrations is at an oblique angle with respect to a central axis of the first segment, wherein the sheath structure further comprises an anchoring assembly disposed distally away from the proximal opening and distal to the fenestrations, the anchoring assembly including at least one selectively activatable anchoring element (194, 150) carried by the first segment, which facilitates anchoring of the sheath structure to a superficial wall of the vessel, wherein the at least one selectively activatable anchoring element (194, 150) is arranged such that a plane through the at least one selectively activatable anchoring element (194, 150) is at an oblique angle with respect to the central axis of the first segment. a first tube having an elongate length, a distal end, a proximal end, and a lumen (110, 210) therebetween for channeling a fluid, the first tube including: a distal portion coupled to the distal end and configured for receiving an endovascular or transcatheter device; a valve portion disposed near or at the distal end, the valve portion including at least one valve and configured for preventing backflow of a first portion of the fluid out of the distal end; and a first segment configured to entirely reside within the vessel when the vessel is cannulated, the first segment comprising: a first lumen therein fluidically coupled to the lumen of the first tube a proximal opening configured for receiving the fluid from a pumping source and channeling the fluid into the first lumen; and a set of fenestrations disposed distal to the proximal opening and fluidically coupled thereto, the set of fenestrations configured for distally outputting or discharging a second portion of the fluid into the vessel, a distal portion coupled to the distal end and configured for receiving an endovascular or transcatheter device; a valve portion disposed near or at the distal end, the valve portion including at least one valve and configured for preventing backflow of a first portion of the fluid out of the distal end; and a first segment configured to entirely reside within the vessel when the vessel is cannulated, the first segment comprising: a first lumen therein fluidically coupled to the lumen of the first tube a proximal opening configured for receiving the fluid from a pumping source and channeling the fluid into the first lumen; and a set of fenestrations disposed distal to the proximal opening and fluidically coupled thereto, the set of fenestrations configured for distally outputting or discharging a second portion of the fluid into the vessel, a first lumen therein fluidically coupled to the lumen of the first tube a proximal opening configured for receiving the fluid from a pumping source and channeling the fluid into the first lumen; and a set of fenestrations disposed distal to the proximal opening and fluidically coupled thereto, the set of fenestrations configured for distally outputting or discharging a second portion of the fluid into the vessel, characterised in that the set of fenestrations is arranged around a portion of the periphery of the first segment such that a plane through the fenestrations is at an oblique angle with respect to a central axis of the first segment, wherein the sheath structure further comprises an anchoring assembly disposed distally away from the proximal opening and distal to the fenestrations, the anchoring assembly including at least one selectively activatable anchoring element (194, 150) carried by the first segment, which facilitates anchoring of the sheath structure to a superficial wall of the vessel, wherein the at least one selectively activatable anchoring element (194, 150) is arranged such that a plane through the at least one selectively activatable anchoring element (194, 150) is at an oblique angle with respect to the central axis of the first segment.