Outcomes of secondary stent-in-stent self-expandable metal stent insertion for malignant colorectal obstruction

Background: Although self-expandable metal stents (SEMSs) are widely used for the treatment of malignant colorectal obstruction, they often become occluded by tumor ingrowth. Objectives: To determine the therapeutic effectiveness of secondary stent-in-stent SEMS insertion for the management of occluded SEMS in patients with malignant colorectal obstruction and to identify predictive factors associated with clinical outcomes in terms of immediate clinical success, stent patency, and complications. Design: Retrospective case series. Setting: A tertiary-care academic medical center in South Korea. Patients: Between November 2005 and July 2010, among a total of 309 patients who underwent SEMS insertion for unresectable malignant colorectal obstruction at Severance Hospital, 87 underwent secondary SEMS insertion. Of these, 36 patients underwent secondary SEMS placement as stent-in-stent. Interventions: Placement of secondary colorectal stent-in-stent SEMSs. Main Outcome Measurements: Immediate and long-term clinical success and complications. Results: Immediate clinical success was achieved in 27 of 36 patients (75%), and the median duration of stent patency was 170 days. Factors associated with immediate clinical success included a long duration between the previous stent and stent-in-stent insertion. Moreover, the absence of carcinomatosis was associated with long-term clinical success. Limitations: This was a retrospective, nonrandomized, single-center study. Conclusions: Secondary stent-in-stent SEMS placement led to good outcomes in patients with malignant colorectal obstruction, despite a slightly lower success rate compared with primary SEMS placement. Patency duration of the primary SEMS and carcinomatosis were important factors predictive of immediate and long-term clinical success of stent-in-stent insertion, respectively.