The present invention relates to an implant for controlling blood perfusion within a vessel (11), especially the portal vein, comprising an inflatable band assembly including a) an non-extendible band (4) configured to be releasably secured around the vessel (11), wherein the band (4) comprises a tail end and a head end for receiving said tail end and a releasable locking means (6) securing said head and tail ends of said band (4) in an encircling position, and wherein said band (4) includes at least one inflatable balloon (3) arranged at the inner side of the band in its encircling position, said at least one inflatable balloon (3) extending up to 60% over the inner circumference of the band (4) in its encircling position, b) an injection port (1) with a resealable membrane (5) or a reservoir comprising a fluid, and c) an inflation tube (2) providing for fluid communication between the injection port (1) or the reservoir and the at least one inflatable balloon (3) of the band assembly, characterised in that at the inner side of the band assembly in its encircling position a means for measuring the blood flow (14) within the vessel (11) is arranged.La présente invention concerne un implant destiné à réguler une perfusion sanguine dans un vaisseau (11), en particulier dans la veine porte, comportant un ensemble bande gonflable comprenant les éléments suivants : a) une bande non extensible (4) conçue pour être fixée de manière libérable autour du vaisseau (11), ladite bande (4) comprenant une extrémité de queue et une extrémité de tête permettant daccueillir ladite extrémité de queue, ainsi quun moyen de verrouillage libérable (6) fixant lesdites extrémités de tête et de queue de ladite bande (4) dans une position dencerclage, ladite bande (4) comprenant au moins un ballon gonflable (3) disposé sur le côté interne de la bande dans sa position dencerclage, ledit au moins un ballon gonflable (3) sétendant jusquà 60 % sur la circonférence interne de la bande (4) dans sa
