Partially Covered Versus Uncovered Pyloro-duodenal Stents for Unresectable Malignant Gastric Outlet Obstruction. A Double Blinded Randomised Controlled Trial.

The PCDS (Niti-S COMVITM - Flare, Taewoong, Gyeonggi-do, South Korea) used in the current study is a partially covered metallic pyloro-duodenal stent. It consists of two portions (Figure 1). The stent is 2cm in diameter and the proximal 2cm of the stent is uncovered and flared. This is designed to provide anchorage of the stent to surrounding tissue and reduce the risk of migration. The remaining of the stent is covered, where a polytetrafluoroethylene (PTFE) membrane is held between two nitinol mesh to prevent the risk of tumour ingrowth into the stent. The stents come in lengths of 6, 8, 10 \& 12cm.

The UCDS (Niti-S pyloric-duodenal D stent, Taewoong, Gyeonggi-do, South Korea) used in the current study is an uncovered stent made of nitinol wire, with a diameter of 20mm and length of 6,8,10,12cm. This stent is an unfixed-cell braided stent with low axial force, high flexibility and good conformability.