Objectives: Self-expanding metal stents (SEMS) are increasingly being used to treat malignant colorectal obstruction. However, complications have been reported in up to 50% of patients. There is limited information on long-term outcomes of these patients. The aim of this study was to retrospectively assess the long-term clinical success of SEMS in patients with malignant colorectal obstruction in a single tertiary center and to identify possible predictive factors of developing complications.
Methods: A total of 47 attempts to insert colorectal SEMS were made in 47 patients during a 5-year period. Stents of 9-cm length were placed under endoscopic and radiologic monitoring. After 24 h, all patients underwent abdominal X-ray to verify correct positioning of the stent. Patients were followed at the outpatient clinic.
Results: Insertion success was achieved in 44 (94%) patients. Acceptable initial colonic decompression was observed in 44 out of 47 (94%) attempts and in all (100%) successfully inserted stents. The stents were placed in the rectum (n=7, 15%), sigmoid (n=33, 70%), left colon (n=4, 9%), or anastomosis (n=3, 6%). The majority of patients had stage IV disease (n=40, 85%). SEMS served as a bridge to scheduled surgery in 9 (20%) patients and as a palliative definitive treatment in 38 (80%) cases. Three patients were lost to follow-up, so the outcome was evaluated in 41 patients. Long-term clinical failure occurred in 21 (51%) patients and was due to complications such as: migration (n=9, 22%), obstruction (n=7, 17%), perforation (n=3, 7%), and tenesmus (n=2, 5%). Perforations occurred 3, 4, and 34 days after insertion, and all patients died. In the bridge-to-surgery group, primary anastomosis was possible in only four of nine patients (44%). Clinical failure was not associated with any tumor-related factor. However, eight of nine patients with stent migration and two of three patients with perforation had been previously treated with chemotherapy.
Conclusions: Placement of SEMS does not seem to be as effective as suggested because of late complications. For patients with potentially curable lesions, the use of colonic stents for malignant obstruction should only be considered when surgery is scheduled shortly after the stent insertion. Moreover, in patients with incurable obstructing colorectal cancer eligible for chemotherapy and a long life expectancy, palliative treatments other than SEMS should be considered.