抗肿瘤5-Fu和紫杉醇药物缓释支架：猪食管内安全实验

Background: A poor prognosis associated with esophageal cancer leads to surgical resection not suitable formost patients. Nitinol stents loaded with 50% 5-fluorouracil (5-FU) or paclitaxel (PTX), functioning both as a stent
and local chemotherapy, could provide a new therapy modality for these patients.
Objective: To investigate esophageal tissue responses to nitinol stents loaded with 50% 5-FU or PTX implanted
in the esophagus of healthy pigs.
Design: Twenty-three healthy Bama mini-pigs were randomly divided into 4 groups for stent implantation: group
A (PTX stent, n Z 13), group B (5-FU stent, n Z 8), group C (blank film–covered stent, n Z 1), and group D
(bare stent, n Z 1). Tissue responses were observed by endoscopy or pathologic analyses, and 5-FU or PTX con-
centrations were measured in the esophagus at the stent implantation site at different time points.
Setting: Animal laboratory.
Interventions: Endoscopic placement of esophagus stent.
Main Outcome Measurements: Endoscopic examination, histology, and drug concentration analysis.
Results: Ingeneral,theesophagealtissueresponsesvariedaccordingtodifferentpartsof5-FUorPTXstent(middle
part [drug-containing part] and bare ends [drug-free part]). Severe tissue responses at the bare ends of the stent
includedinflammation,ulceration,andgranulation.However,thetissueresponsesweregreatlyreducedinthemid-
dlepartofthestent.Thedrugconcentrationsintheesophagusthathadcontactwiththe5-FUstentorPTXstentwere
very high, especially for the first period after implantation, which did not cause obvious tissue damage.
Limitation: Some subjects had incomplete follow-up because of unexpected deaths and stent migration.
Conclusion: The nitinol stents loaded with 50% 5-FU or PTX did not cause severe esophageal tissue responses,
although there was a large concentration of the drug in these tissues.