Reply to Matsushita et al. Regarding Management of a Distally Migrated Self-Expanding Metal Stent

We appreciated the alternative approach to management of an occluded, distally migrated biliary self-expanding metal stent (SEMS) as outlined by Matsushita et al. Distal migration of SEMSs has resulted in a number of notable complications, including pressure necrosis and ulceration, gastrointestinal bleeding, and duodenal perforation [1] [2] [3]. Furthermore, their relative permanency makes endoscopic extraction difficult if not impossible.

The distally migrated, uncovered SEMS in our patient appeared to be deeply embedded to an unknown depth within the contralateral duodenal wall. We felt that traction removal as described by Matsushita et al., or use of the “lasso technique” as described elsewhere, risked ductal injury, excessive duodenal trauma, and free duodenal perforation, due to the stent’s size and stiffness [4] [5] [6] [7]. Traction removal of more malleable, plastic stents is probably safer and better suited to the well-described, efficient technique of Matsushita et al. Piecemeal extraction of a stent, with or without the assistance of an endoscopic suture removal device, is a tedious technique and may not be possible in a significant percentage of cases [8] [9] [10]. Percutaneous extraction carries with it not only the risk of ductal injury but also of hepatic injury, bleeding, and bile peritonitis [11]. Surgery should obviously be reserved for cases refractory to endoscopic stent retrieval or shortening.

Our recommended approach for distal SEMS impaction, therefore, is to effectively shorten the metal stent by “endoscopic trimming”. This is best accomplished by using thermal energy emitted via laser or argon plasma coagulator to shorten the stent to a desired length, enabling access. As lasers are not readily available in many endoscopic retrograde cholangiopancreatography suites and expertise is waning, argon plasma coagulation may prove to be a more convenient and cost-effective approach to endoscopic metal stent trimming [12].

The separate issue of optimal management of an occluded SEMS was also addressed. The authors cited a retrospective study of only 34 patients by Bueno et al. [13], where placement of a “stent in stent” resulted in significantly longer patency rates. As only six of 34 patients underwent mechanical cleaning, definitive conclusions cannot be drawn. In the case that we described, the primary mechanism of stent occlusion related to its duodenal impaction rather than to the more common causes of stent obstruction such as tumor or hyperplastic biliary epithelium ingrowth or overgrowth. Consequently, we felt that trimming of the stent with mechanical cleaning of biliary and food debris was a durable intervention.

References

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