Nagae T, Tsuchida H, Ishimaru S, Wilson S E
Department of Surgery, University of California, Irvine, USA.
J Invest Surg. 1995 Jul-Aug;8(4):235-42. doi: 10.3109/08941939509031597.
Highly porous PTFE arterial prostheses form endothelium more extensively than the low-porosity grafts in clinical use, but are subject to seroma formation. PTFE vascular grafts were modified to produce a highly porous inner layer (inner layer 60 or 90 microns, outer layer 20 microns). The effect of this modified, composite design on the histology of graft healing was investigated. Twenty-five modified and 25 control grafts, each 4 mm in diameter by 5 cm in length, were implanted into carotid and femoral arteries of dogs. No late seroma formation was observed. After 12 and 18 weeks, the neointima of the grafts was examined by light microscopy and scanning electron microscopy. At 2- and 4-mm distances from the proximal and distal anastomoses, intimal thickness of the control grafts was 238.7 and 96.1 microns, respectively; for the modified grafts it was 236.2 and 202.8 microns at 18 weeks. Thus, the neotinima of modified grafts was thicker than that of control grafts when measured at 4 mm from the anastomoses. Neointimal coverage was less extensive in the control grafts than in modified grafts (26.8 +/- 6.1% vs. 58.8 +/- 13.2%; p < .05). Smooth muscle cells were seen on light-microscopy to penetrate the highly porous inner layer; on scanning electron microscopy, the PTFE fibrils appeared to anchor the neointima of the modified graft. The results suggest that modified PTFE grafts with an inner surface of 60 or 90 microns internodal distance have enhanced formation and anchoring of neointima while remaining impervious to blood.
高度多孔的聚四氟乙烯动脉假体比临床使用的低孔隙率移植物更广泛地形成内皮，但容易形成血清肿。对聚四氟乙烯血管移植物进行了改良，以产生高度多孔的内层（内层60或90微米，外层20微米）。研究了这种改良的复合设计对移植物愈合组织学的影响。将25个改良移植物和25个对照移植物（每个直径4毫米，长度5厘米）植入狗的颈动脉和股动脉。未观察到晚期血清肿形成。在12周和18周后，通过光学显微镜和扫描电子显微镜检查移植物的新生内膜。在距近端和远端吻合口2毫米和4毫米处，对照移植物的内膜厚度分别为238.7微米和96.1微米；在18周时，改良移植物的内膜厚度分别为236.2微米和202.8微米。因此，在距吻合口4毫米处测量时，改良移植物的新生内膜比对照移植物的新生内膜厚。对照移植物的新生内膜覆盖范围比改良移植物小（26.8±6.1%对58.8±13.2%；p<0.05）。光学显微镜下可见平滑肌细胞穿透高度多孔的内层；扫描电子显微镜下，聚四氟乙烯纤维似乎固定了改良移植物的新生内膜。结果表明，节距为60或90微米的改良聚四氟乙烯移植物增强了新生内膜的形成和固定，同时保持了血液不透性。
