An interventional device, the interventional device being an elongated surgical device for en bloc transurethral removal of bladder tumours, said interventional device comprising: - a bag, such as a specimen retrieval bag, wherein said bag comprises a first opening and a second opening, and wherein said bag is arranged for being transformable between - an open configuration, and - a closed configuration wherein said second opening is smaller than in the open configuration, such as wherein in the closed configuration said second opening is smaller than said first opening, - a shaft, such as wherein the shaft defines an axis along a longitudinal direction of said shaft, wherein said shaft extends through said first opening, - a grasper, wherein said grasper is mounted on a distal end of said shaft, wherein in the open configuration the second opening is movable relative to the first opening and the grasper between - a first position wherein the second opening is on an opposite side of the first opening with respect to the grasper, - a second position wherein the grasper is located between the second opening and the first opening, wherein the bag further comprises a fluid passageway arranged so that in the closed configuration the fluid passageway enables that fluid may be expelled through the fluid passageway from an interior volume of the bag to an exterior volume of the bag and furthermore enables that a solid element, such as tumour or a piece of a tumour, above a predetermined threshold size may be retained in the bag, wherein the shaft is at least partially placed inside an elongated tubular body, and wherein the shaft is arranged for extending through a distal opening of said tubular body so that the grasper is outside of the tubular body at the distal end of the tubular body, and when - the first opening is outside of the elongated tubular body, - the second opening is in the second position, and - said bag is in the closed configuration, and the second opening is fluid-tight the second opening may be brought closer to the distal opening than the first opening, characterized in that the first opening is not fluid-tight and the fluid passageway is given by the lack of fluid-tightness, so that when removing the interventional device liquid expelled from the first opening ends up in a cavity from which the bag is removed - a bag, such as a specimen retrieval bag, wherein said bag comprises a first opening and a second opening, and wherein said bag is arranged for being transformable between - an open configuration, and - a closed configuration wherein said second opening is smaller than in the open configuration, such as wherein in the closed configuration said second opening is smaller than said first opening, - an open configuration, and - a closed configuration wherein said second opening is smaller than in the open configuration, such as wherein in the closed configuration said second opening is smaller than said first opening, - a shaft, such as wherein the shaft defines an axis along a longitudinal direction of said shaft, wherein said shaft extends through said first opening, - a grasper, wherein said grasper is mounted on a distal end of said shaft, - a first position wherein the second opening is on an opposite side of the first opening with respect to the grasper, - a second position wherein the grasper is located between the second opening and the first opening, wherein the bag further comprises a fluid passageway arranged so that in the closed configuration the fluid passageway enables that fluid may be expelled through the fluid passageway from an interior volume of the bag to an exterior volume of the bag and furthermore enables that a solid element, such as tumour or a piece of a tumour, above a predetermined threshold size may be retained in the bag, wherein the shaft is at least partially placed inside an elongated tubular body, and wherein the shaft is arranged for extending through a distal opening of said tubular body so that the grasper is outside of the tubular body at the distal end of the tubular body, and when wherein the bag further comprises a fluid passageway arranged so that in the closed configuration the fluid passageway enables that fluid may be expelled through the fluid passageway from an interior volume of the bag to an exterior volume of the bag and furthermore enables that a solid element, such as tumour or a piece of a tumour, above a predetermined threshold size may be retained in the bag, wherein the shaft is at least partially placed inside an elongated tubular body, and wherein the shaft is arranged for extending through a distal opening of said tubular body so that the grasper is outside of the tubular body at the distal end of the tubular body, and when - the first opening is outside of the elongated tubular body, - the second opening is in the second position, and - said bag is in the closed configuration, and the second opening is fluid-tight the second opening may be brought closer to the distal opening than the first opening, characterized in that the first opening is not fluid-tight and the fluid passageway is given by the lack of fluid-tightness, so that when removing the interventional device liquid expelled from the first opening ends up in a cavity from which the bag is removed the second opening may be brought closer to the distal opening than the first opening, characterized in that the first opening is not fluid-tight and the fluid passageway is given by the lack of fluid-tightness, so that when removing the interventional device liquid expelled from the first opening ends up in a cavity from which the bag is removed