The invention relates to a coring device for forming an opening in a tissue wall, this device comprising: - a body having a longitudinal axis, said body having a proximal end and a distal end, said body having an internal recess, - a coring head (13) having a transection blade (14), this head being movable between a rest position and an actuated position, - an actuation mechanism for moving said head between said positions, said mechanism having an actuation rod (15), at one end of which said movable head is placed, - a lumen (20) extending through at least the proximal end of said body, said actuation rod (15) and said coring head (13) to allow the passage of a flexible guide element, and - the distal end of said body forms a support (21) for a surgical tool, this tool support (21) being configured, on the one hand, to receive a hollow surgical tool (22) with a positive fit and to support this tool, this tool surrounding the distal end of said body when it is placed on said tool support (21), by being coaxial with said coring axis, and, on the other hand, to permit linear guiding of said surgical tool (22) during the movement of the latter towards the outside of the coring device.L'invention concerne un dispositif de carottage pour réaliser une ouverture dans une paroi tissulaire, ce dispositif comprenant : - un corps ayant un axe longitudinal, ledit corps ayant une extrémité proximale et une extrémité distale, ledit corps comportant un logement interne, - une tête de carottage (13) comportant une lame de transsection (14), cette tête étant mobile entre une position de repos et une position actionnée, - un mécanisme d'actionnement pour déplacer ladite tête entre lesdites positions, ledit mécanisme comportant une tige d'actionnement (15) à une extrémité de laquelle est placée ladite tête mobile, - une lumière (20) s'étendant à travers au moins l'extrémité proximale dudit corps, ladite tige d'actionnement (15) et ladite tête de carottage (13) pour le passage d'un élé
