Table 4.

Causes of recurrent biliary obstruction

Cause	Definition
Tissue ingrowth/mucosal hyperplasia	Growth of cancer or hyperplastic mucosa into the lumen of SEMS
Tissue overgrowth	Tumour or tissue growth beyond the ends of SEMS
Sludge, hemobilia and food impaction	Occlusion of stent lumen by biliary sludge accumulation, clots and food impaction
Bile duct kinking	Obstruction at a proximal or distal end of SEMS due to an angulated bile duct
Stent kinking	Obstruction of stent lumen due to sharp bending of a SEMS because of an angulated bile duct or tumour growth

SEMS, self-expandable metallic stents.