Retrievable covered nitinol stents: experiences in 108 patients with malignant esophageal strictures

PURPOSE: The authors report their experience with three types of retrievable covered nitinol stents in patients with malignant esophageal strictures. MATERIALS AND METHODS: Three types of retrievable covered nitinol stents were designed. Type A stents were placed in 45 patients, type B stents were placed in 29 patients, and type C stents were placed in 34 patients. The stents were removed with use of a stent retrieval set under fluoroscopic guidance when the stents caused complications. Stent patency, symptom relief, survival rate, and complications were analyzed relative to stent type and radiation therapy. RESULTS: The timing of radiation and the stent type have significant effects on occurrence of complications such as stent migration and fistula formation (P =.002 and P = 0.029, respectively). Complications were significantly more frequent in patients with the type B stent than those with type A or type C stents (P =.008). Patients who underwent radiation therapy before stent placement or who underwent no radiation therapy experienced substantially less complications than those who underwent radiation therapy after stent placement (P =.005 and P <.001, respectively). The survival period was significantly longer in patients who underwent radiation therapy after stent placement than in the other groups (P =.034). Stents were removed from 15 patients (14%) 2 days to 16 weeks (mean, 4 weeks) after stent placement as a result of severe pain (n = 7), stent migration (n = 6), or stent deformity (n = 2). Stent removal was well tolerated in all patients. CONCLUSION: Use of retrievable covered nitinol stents seems to be a safe and effective method of treatment in patients with malignant esophageal strictures. However, removal of the stents was needed in 14% of the patients because of complications. Patients who underwent radiation therapy after stent placement and those with the type B stent experienced more complications than other patients.