A double-layered (comvi) self-expandable metal stent for malignant gastroduodenal obstruction: a prospective...

A self-expandable metal stent (SEMS) has emerged as an effective palliative treatment for malignant gastroduodenal obstruction resulting from gastric or periampullary malignancy. Despite the stent's effectiveness, tumor ingrowth and stent migration remain complications requiring reintervention. The purpose of this study was to evaluate the efficacy and safety of a double-layered SEMS (Comvi).

We performed a prospective multicenter study in two university hospitals and two referral hospitals. In fifty consecutive patients with malignant gastroduodenal obstructions, placement of double-layered SEMS, comprising an outer uncovered stent and an inner covered stent that overlap each other, was performed. Palliation, efficacy, and incidence of complications were evaluated.

Technical and clinical success was achieved in 100 and 88% of patients, respectively. There were no procedure-related complications. Five patients experienced stent migration (10%). For four of five patients' stent migration occurred within two weeks of stent placement. Stent collapse occurred in five patients after one month. Reintervention for stent migration, collapse, or tumor overgrowth was required for 14 (28%) patients.

Endoscopic placement of a double-layered stent is a safe and effective modality for the palliation of malignant gastroduodenal obstruction. However, considering reintervention, this stent does not seem to add any clear advantage compared with preexisting uncovered stents. Migration, especially within the first two weeks, and stent collapse are still unresolved problems. The device should be fixed or the design modified to reduce these problems.