OBJECTIVETo explore long-term effect of the treatment of refractory benign esophageal strictures with a novel retrievable fully covered stent made of nitinol alloy.

METHODSFrom November 2009 to May 2011, the stents were placed in 8 patients with refractory benign esophageal strictures in the Department of Thoracic Surgery at the Cancer Center of Sun Yat-sen University. Esophago-gastro-duodenoscopy and barium swallow examinations were performed respectively on the 1st, 7th, 30th, 60th day after implantations of the stents and 1,2,3,6 months or even longer after removal of the stents in order to assess the long-term effect on the improvement of dysphagia and the development of complications.

RESULTSThe stents were successful deployed in all the patients. The dysphagia scores were improved instantly and significantly as compared to the preoperative scores(P<0.05). Seven patients had long-term improvement of dysphagia. The dwelling time of all the stents ranged from 4 to 60 weeks, with a median of 16.8 weeks. Six patients had their stent removed after a dwelling time of 4 to 18 weeks(median 9.7 weeks). The follow-up period was 1.5-9 months (median 6.1 months). The improvement of dysphagia was also significant during follow-up after removal of the stents(P<0.05). At the most recent follow up, two patients still had the stent in place. The first one has already been followed up for 15 months and was still on regular diet. The other one experienced improvement of dysphagia score up to two months after placement, but downgraded to 3 by the third month. Relapse of stenosis occurred in 1 patient, migration in 2 patients, and tissue hyperplasia in 3 patients, of whom 2 developed inward growth of granulation tissue due to the rupture of the covering membrane.

CONCLUSIONSThe new retrievable fully covered stent made of nitinol alloy significantly improves the swallowing function of patients with intractable benign esophageal strictures after implantation and after removal of the stents, with low incidence of long-term restenosis. However, the high rate of migrations and the poor quality of the covering membrane further implies that the design of the new stent still needs to be improved.