The blood supply of the human bile duct has been re-evaluated using high resolution resin casts prepared from 24 fresh human cadavers. The refined technique used yielded casts of all vessels, including capillaries, and produced a clear picture of the blood supply of the human bile duct for the first time. The arterial supply of the supraduodenal duct was shown to be axial, with the main vessels, which have been named the 3 o'clock and 9 o'clock arteries, running along the lateral borders. The retroportal artery, which has not been described by previous workers, was present in all complete casts and was a major source of the axial blood supply to the supraduodenal duct in 32 per cent of them.

The major importance of this new knowledge of bile duct blood supply may well lie in the understanding of the aetiology of postoperative bile duct strictures and in their prevention. An explanation is proposed for the long strictures sometimes seen after minimal surgical trauma to the bile duct, based on damage to the small vessels supplying the duct; guidelines to prevent such damage are presented. Ischaemia of the bile duct may also explain some of the biliary problems that have followed human liver transplantation and other procedures involving biliary anastomosis, such as Whipple's operation.