A stent system and inflatable apparatus for deploying a stent system (10,110) in a bifurcated vessel having a main branch from which a side branch extends therefrom, the inflatable apparatus comprising: a primary inflatable portion having proximal and distal ends, and a secondary inflatable portion extending away from a region between said proximal and distal ends (80,82) of said primary inflatable portion, said primary inflatable portion positionable within said main branch and said secondary inflatable portion positionable within said side branch such that when said primary and secondary inflatable portions (68,70) are inflated, said primary inflatable portion expands radially in said main branch while said secondary inflatable portion maintains registration with said side branch by expanding radially therein; the stent system (10,110) comprising: a first radially-expandable stent (12,112) positionable on said primary inflatable portion, wherein when said primary inflatable portion is inflated, said first stent (12,112) radially expands within said main branch, said first radially-expandable stent (12,112) comprising a side opening (16,116) through which said secondary inflatable portion extends; and a second radially-expandable stent (14,114) positionable on said secondary inflatable portion, wherein when said secondary inflatable portion is inflated, said second stent (14,114) radially expands, said second stent (14,114) having a proximal (18,118) and distal end and said proximal end (18,118) being shaped to cooperate with said opening (16,116) of said first stent (12,112) upon expansion; characterised in that said second stent (14,114) further comprises a generally semicircular expandable alignment brace extending from the shaped proximal end (18,118) of said second stent (14,114) by deformable joints, said alignment brace forming a generally tubular transverse opening with the shaped proximal end (18,118), said alignment brace permitting more accurate positioning of said shaped end (18,118) of said second stent (14,114) with the complementary opening (16,116) of said first stent (12,112) upon expansion, said alignment brace being adapted to have said primary inflatable portion extend therethrough, so that when said primary and secondary inflatable portions (68,70) are inflated, said primary inflatable portion expands said alignment brace within the internal circumference of the first stent (12,112) and aligns the shaped end of the second stent (14,114) with the opening (16,116) of the first stent (12,112). a primary inflatable portion having proximal and distal ends, and a secondary inflatable portion extending away from a region between said proximal and distal ends (80,82) of said primary inflatable portion, said primary inflatable portion positionable within said main branch and said secondary inflatable portion positionable within said side branch such that when said primary and secondary inflatable portions (68,70) are inflated, said primary inflatable portion expands radially in said main branch while said secondary inflatable portion maintains registration with said side branch by expanding radially therein; the stent system (10,110) comprising: a first radially-expandable stent (12,112) positionable on said primary inflatable portion, wherein when said primary inflatable portion is inflated, said first stent (12,112) radially expands within said main branch, said first radially-expandable stent (12,112) comprising a side opening (16,116) through which said secondary inflatable portion extends; and a second radially-expandable stent (14,114) positionable on said secondary inflatable portion, wherein when said secondary inflatable portion is inflated, said second stent (14,114) radially expands, said second stent (14,114) having a proximal (18,118) and distal end and said proximal end (18,118) being shaped to cooperate with said opening (16,116) of said first stent (12,112) upon expansion; characterised in that a first radially-expandable stent (12,112) positionable on said primary inflatable portion, wherein when said primary inflatable portion is inflated, said first stent (12,112) radially expands within said main branch, said first radially-expandable stent (12,112) comprising a side opening (16,116) through which said secondary inflatable portion extends; and a second radially-expandable stent (14,114) positionable on said secondary inflatable portion, wherein when said secondary inflatable portion is inflated, said second stent (14,114) radially expands, said second stent (14,114) having a proximal (18,118) and distal end and said proximal end (18,118) being shaped to cooperate with said opening (16,116) of said first stent (12,112) upon expansion; characterised in that said second stent (14,114) further comprises a generally semicircular expandable alignment brace extending from the shaped proximal end (18,118) of said second stent (14,114) by deformable joints, said alignment brace forming a generally tubular transverse opening with the shaped proximal end (18,118), said alignment brace permitting more accurate positioning of said shaped end (18,118) of said second stent (14,114) with the complementary opening (16,116) of said first stent (12,112) upon expansion, said alignment brace being adapted to have said primary inflatable portion extend therethrough, so that when said primary and secondary inflatable portions (68,70) are inflated, said primary inflatable portion expands said alignment brace within the internal circumference of the first stent (12,112) and aligns the shaped end of the second stent (14,114) with the opening (16,116) of the first stent (12,112).