Chung Hwan-Hoon, Lee Seung Hwa, Cho Sung Bum, Park Hong Suk, Kim Young Sik, Kang Byung Chul, Frisoli Joan K, Razavi Mahmood K
Department of Radiology, Ansan Hospital, Korea University College of Medicine, Gojan Dong 516, Ansan City, Kyonggido 425-707, South Korea.
Cardiovasc Intervent Radiol. 2008 May-Jun;31(3):619-28. doi: 10.1007/s00270-007-9087-5.
The aim of this study was to determine the feasibility of using a newly designed polytetrafluoroethylene (PTFE)-covered metallic stent in the ureter by comparing its effectiveness with that of the noncovered stent in a canine model. We placed 14 stents in the ureters of seven mongrel dogs that weighed 30-40 kg each. The covered and noncovered stents were deployed in the right and left ureters, respectively, of six dogs. In the seventh dog, a covered stent and a double-J catheter were inserted in the right ureter, and a covered stent only was inserted in the left ureter. The first six dogs were sacrificed at 5, 10, and 15 weeks after deployment of the stents (two for each follow-up period), and the seventh dog was sacrificed at 30 weeks. There was no migration or poor expansion of any of the stents observed on plain radiography. On intravenous pyelogram and retrograde pyelogram, all of the covered stents at each follow-up period had patent lumens at the stented segments without hydronephrosis, and the passage of contrast material through it was well preserved. The noncovered stents in the dogs sacrificed at 5 and 10 weeks and one of the two dogs sacrificed at 15 weeks showed near-complete occlusion of the stent lumen due to ingrowth of the soft tissue, and severe hydronephrosis was also noted. The noncovered stent in the other dog sacrificed at 15 weeks showed the passage of contrast material without hydronephrosis, but the lumen of the stent was still nearly occluded by the soft tissue. There was no evidence of hydronephrosis or passage disturbance of the contrast material in both ureters of the dog sacrificed at 30 weeks. We conclude that the newly designed PTFE-covered stent effectively prevented the luminal occlusion caused by urothelial hyperplasia compared to the near-total occlusion of the noncovered stents, and no migration of the covered stents was noted.
本研究的目的是通过在犬模型中比较新设计的聚四氟乙烯（PTFE）覆膜金属支架与未覆膜支架的有效性，来确定其在输尿管中使用的可行性。我们在7只体重为30 - 40千克的杂种犬的输尿管中放置了14个支架。在6只犬中，覆膜支架和未覆膜支架分别部署在右侧和左侧输尿管。在第7只犬中，右侧输尿管插入一个覆膜支架和一个双J导管，左侧输尿管仅插入一个覆膜支架。在前6只犬支架植入后5周、10周和15周处死（每个随访期2只），第7只犬在30周处死。在X线平片上未观察到任何支架有移位或扩张不良的情况。在静脉肾盂造影和逆行肾盂造影中，每个随访期的所有覆膜支架在支架段的管腔通畅，无肾积水，造影剂通过良好。在5周和10周处死犬体内的未覆膜支架以及在15周处死的2只犬中的1只，由于软组织长入，支架管腔几乎完全闭塞，并且还发现了严重肾积水情况；在15周处死的另一只犬体内的未覆膜支架，造影剂可通过，无肾积水，但支架管腔仍几乎被软组织闭塞。在30周处死犬的双侧输尿管中，均未发现肾积水或造影剂通过障碍迹象。我们得出结论，与未覆膜支架几乎完全闭塞相比，新设计的PTFE覆膜支架有效防止了由尿路上皮增生引起的管腔闭塞，并且未观察到覆膜支架有移位情况。
