A multi-lumen cannula comprising: a coaxial double lumen cannula having an inner lumen and an outer lumen and a proximal end and a distal end, wherein one lumen (12, 14) possesses a coolant and the other lumen (12, 14) possesses a composition comprising a thermally responsive polymer; wherein the thermally responsive polymer is in a first viscosity state at a pre-treatment temperature and a second viscosity state at a treatment temperature that is higher than the pre- treatment temperature, wherein the viscosity of the second viscosity state is greater than the viscosity of the first viscosity state; wherein the coaxial double lumen cannula comprises an inner lumen possessing the coolant and an outer lumen possessing the composition comprising the thermally responsive polymer; or wherein the coaxial double lumen cannula comprises an inner lumen possessing the composition comprising the thermally responsive polymer and an outer lumen possessing the coolant; and characterized in that the coolant prevents premature gelation of the thermally responsive polymer and wherein the coolant: (i) is a cooled liquid; (ii) is a cooled gas; (iii) comprises a solution selected from the group consisting of ammonium nitrate crystals in water, potassium iodide in water, ammonium chloride in water, ammonium acetate in water, potassium thiocyanate in water, ammonium thiocyanate in water, sodium thiosulfate in water, ammonium bromide in water, urea based solutions, and combinations thereof; or (iv) is a combination of (i), (ii) and/or (iii). a coaxial double lumen cannula having an inner lumen and an outer lumen and a proximal end and a distal end, wherein one lumen (12, 14) possesses a coolant and the other lumen (12, 14) possesses a composition comprising a thermally responsive polymer; wherein the thermally responsive polymer is in a first viscosity state at a pre-treatment temperature and a second viscosity state at a treatment temperature that is higher than the pre- treatment temperature, wherein the viscosity of the second viscosity state is greater than the viscosity of the first viscosity state; wherein the coaxial double lumen cannula comprises an inner lumen possessing the coolant and an outer lumen possessing the composition comprising the thermally responsive polymer; or wherein the coaxial double lumen cannula comprises an inner lumen possessing the composition comprising the thermally responsive polymer and an outer lumen possessing the coolant; and characterized in that the coolant prevents premature gelation of the thermally responsive polymer and wherein the coolant: (i) is a cooled liquid; (ii) is a cooled gas; (iii) comprises a solution selected from the group consisting of ammonium nitrate crystals in water, potassium iodide in water, ammonium chloride in water, ammonium acetate in water, potassium thiocyanate in water, ammonium thiocyanate in water, sodium thiosulfate in water, ammonium bromide in water, urea based solutions, and combinations thereof; or (iv) is a combination of (i), (ii) and/or (iii). (i) is a cooled liquid; (ii) is a cooled gas; (iii) comprises a solution selected from the group consisting of ammonium nitrate crystals in water, potassium iodide in water, ammonium chloride in water, ammonium acetate in water, potassium thiocyanate in water, ammonium thiocyanate in water, sodium thiosulfate in water, ammonium bromide in water, urea based solutions, and combinations thereof; or (iv) is a combination of (i), (ii) and/or (iii).