New guide wire technique for stent placement through an occluded self-expandable metal stent: The hairpin technique

Self-expandable metal stents (SEMS) for malignant biliary strictures sometimes occlude, requiring the insertion of another stent. When a guide wire is advanced conventionally through the proximal portion of an occluded SEMS, the guide wire sometimes penetrates the stent mesh. The present study reports a new guide wire insertion technique that prevents this problem from occurring.

In this new method of advancing a guide wire, the tip is not straight but bent into a curve. Because the advancing end of the guidewire is rounded like a hairpin, it cannot penetrate the stent mesh. Before cannulation, the flexible tip of the guide wire is extended out of the tip of the cannula in the descending duodenum and then cannulation is carried out as the flexible tip makes a hairpin curve. The guide wire with a maintained hairpin curve is advanced through the proximal end of the SEMS. The hairpin curve pops open and the guide wire straightens out when the guide wire has passed through the SEMS. After that, a second stent can be inserted over the guide wire. This technique has been utilized 14 times for occluded SEMS in 10 patients between June 2001 and September 2003.

In all patients the technique served to ensure access to the biliary tree and successful placement of a second stent.

This new hairpin guide wire technique was effective in preventing the guide wire from penetrating the stent mesh and, therefore contributed to successful stent placement within occluded SEMS.