Jung-Hoon Park1, Young Kwon Cho2, Keun Her3, Yong Sun Jeon4, Jeong Ho Kim5, Tae-Seok Seo6, Myung Gyu Song6. 1. Biomedical Engineering Research Center and Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea. 2. Department of Radiology, Kangdong Seong-Sim Hospital, Hallym University College of Medicine, 150 Seongan-ro, Gangdong-gu, Seoul, 134-701, Korea. ykchoman@naver.com. 3. Department of Thoracic Surgery, Soonchunhyang Bucheon University Hospital, Soonchunhyang University College of Medicine, Bucheon, Korea. 4. Department of Radiology, Inha University Hospital, Inha University College of Medicine, Incheon, Korea. 5. Department of Radiology, Gachon University Gil Hospital, Gachon University College of Medicine, Incheon, Korea. 6. Department of Radiology, Korea University Guro Hospital, Korea University College of Medicine, Seoul, Korea.
Abstract
PURPOSE: To investigate the technical feasibility of a novel exoskeleton Seal® stent-graft and analyze early histologic changes in the porcine abdominal aorta. MATERIALS AND METHODS: Six pigs received an abdominal stent-graft (Group I), and six received an iliac branch stent-graft (Group II). Groups were subdivided as follows: Group Ia, which received three bifurcated main-body stent-grafts; Group Ib, which received three bifurcated main-body stent-grafts with both iliac graft-stents; Group IIa, which received three simple uni-iliac tapered stent-grafts; and Group IIb, which received three uni-iliac tapered tapered stent-grafts with right straight limb and left branched limb. Statistical analyses were performed with the Wilcoxon signed-rank test and mixed-model regression analysis. RESULTS: The primary technical success rate (< 24 h) was 83% because of two acute thromboses in the lumen of the stented abdominal aorta immediately after stent-graft placement. At 4 weeks, late thrombosis occurred in two pigs. Higher mean neointimal hyperplasia areas (23.5% vs. 16.2%; P = .047), neointimal hyperplasia thicknesses (545.5 μm vs. 422.2 μm; P = .001), and degrees of collagen deposition (2.71 vs. 2.33; P = .002) were observed at the bare-metal stent-graft compared with the proximal exoskeleton portion of the stent-graft, with no significant differences between the patent and occluded groups or among the four types of stent-grafts. CONCLUSIONS: The exoskeleton stent-graft demonstrates 66% of patency rate during 1-month follow-up due to four cases of thromboses; however, the endothelialization on the junction of proximal graft showed no significant differences between the patent and occluded groups. Further studies should investigate long-term outcomes with prolonged neointimal hyperplasia.
PURPOSE: To investigate the technical feasibility of a novel exoskeleton Seal® stent-graft and analyze early histologic changes in the porcine abdominal aorta. MATERIALS AND METHODS: Six pigs received an abdominal stent-graft (Group I), and six received an iliac branch stent-graft (Group II). Groups were subdivided as follows: Group Ia, which received three bifurcated main-body stent-grafts; Group Ib, which received three bifurcated main-body stent-grafts with both iliac graft-stents; Group IIa, which received three simple uni-iliac tapered stent-grafts; and Group IIb, which received three uni-iliac tapered tapered stent-grafts with right straight limb and left branched limb. Statistical analyses were performed with the Wilcoxon signed-rank test and mixed-model regression analysis. RESULTS: The primary technical success rate (< 24 h) was 83% because of two acute thromboses in the lumen of the stented abdominal aorta immediately after stent-graft placement. At 4 weeks, late thrombosis occurred in two pigs. Higher mean neointimal hyperplasia areas (23.5% vs. 16.2%; P = .047), neointimal hyperplasia thicknesses (545.5 μm vs. 422.2 μm; P = .001), and degrees of collagen deposition (2.71 vs. 2.33; P = .002) were observed at the bare-metal stent-graft compared with the proximal exoskeleton portion of the stent-graft, with no significant differences between the patent and occluded groups or among the four types of stent-grafts. CONCLUSIONS: The exoskeleton stent-graft demonstrates 66% of patency rate during 1-month follow-up due to four cases of thromboses; however, the endothelialization on the junction of proximal graft showed no significant differences between the patent and occluded groups. Further studies should investigate long-term outcomes with prolonged neointimal hyperplasia.