Background: Metal stents are not superior to conventional endoprostheses with respect to the incidence of recurrent dysphagia because of tumor ingrowth with uncovered stents and migration with their covered counterparts. To overcome these limitations, a partially covered (inside-out covering) metal stent with a conical shape and a varying braiding angle of the mesh along its length, the Flamingo stent, has been developed.
Methods: From March 1997 to October 1997, 40 consecutive patients with dysphagia due to malignant tumors had either a small diameter (proximal/distal diameter 24/16 mm; n = 21) or a large diameter Flamingo stent (proximal/distal diameter 30/20 mm; n = 19) placed.
Results: There was statistically significant improvement in dysphagia, but improvement was not greater with large diameter stents compared to small diameter stents (p = 0.21). Major complications (bleeding , perforation , fever  and fistula ) occurred in 7 (18%) patients. Large diameter stents tended to be associated with more major complications than small diameter stents (5 vs. 2; p = 0.07). Pain following stent placement was observed in 9 (22%) patients and occurred more frequently in those who had prior radiation and/or chemotherapy (p = 0.02). Recurrent dysphagia (mainly due to tumor overgrowth) occurred in 10 (25%) patients.
Conclusions: Flamingo stents are effective for palliation of malignant dysphagia, but the large diameter stent seems to be associated with more complications involving the esophagus than the small diameter stent. Because recurrent dysphagia is mainly due to tumor progression, further technical developments in stent design are needed.