Tissue dissection during surgery requires the surgeon to get into a desired tissue plane in order to delineate structures, minimize bleeding, and avoid visceral and vascular injury.

Navigating through and around anatomical structures could be compared to walking through a building of corridors. When there is a door in the corridor, it must be opened before being able to progress further. Likewise, in order to get to a corridor at a different level, a passageway must exist between the two levels. Each of these transitions, either forward through a door or down to the next level, requires passage through a ‘gateway’. In surgical dissection, anatomical structures form ‘gateways’ that must be divided in order to progress the dissection along a tissue plane, or to expose a structure at a deeper tissue plane.

In HPB surgery, understanding six key anatomical gateways will facilitate surgical dissection during common procedures. Each of these will be illustrated with specific examples from clinical cases.