PubMed · 6907398
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A Shigeta. 1980. [Angiography].. https://pubmed.ncbi.nlm.nih.gov/6907398/
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BACKGROUND: Recent studies have indicated that coronary restenosis after balloon angioplasty is the sum of geometric remodeling and neointimal formation. A proportional relationship between acute gain and late lumen loss has been observed in clinical trials. The aims of this study were to evaluate (1) the contribution of geometric remodeling and neointimal formation to the proportional gain-loss relationship after PTA or stenting and (2) the relationship between geometric remodeling and neointimal formation. METHODS AND RESULTS: In atherosclerotic iliac arteries of 29 Yucatan micropigs, PTA or stenting was performed, with serial intravascular ultrasound (IVUS) and quantitative angiography before and after intervention and at 2 or 42 days of follow-up, followed by histomorphometrical analysis. For PTA at 42 days, late lumen loss by IVUS correlated strongly with geometric remodeling, expressed as late media-bounded area (MBA) loss (R2=.843, P<.001, n=20), and correlated weakly with intimal hyperplasia area (R2=.214, P=.02). For stented arteries, however, late lumen loss correlated moderately with intimal hyperplasia (R2=.367, P=.01, n=18) and only weakly with geometric remodeling (R2=.195, P=.04). Late lumen loss and late MBA loss of reference segments were observed at 42 days, especially in PTA arteries. Intimal hyperplasia and geometric remodeling were not correlated. CONCLUSIONS: In this experimental model, the proportional relationship between acute gain and late lumen loss is mainly due to the proportional relationship between acute gain and geometric remodeling for PTA and between acute gain and intimal hyperplasia for stents. Finally, neointimal formation and remodeling seem to be unrelated processes.
BACKGROUND: The reconstruction of massive osteochondral defects extending to weight-bearing joints remains a surgical challenge. Total knee joint transplantation has been performed experimentally, but these studies lacked prospective evaluation of functional outcome, graft vascularization, and graft viability. METHODS: Replantation and transplantation of vascularized knee joints was performed in dogs (n=4 per group), comparing functional and morphological results during a 6-month follow-up. RESULTS: All replant recipients and three transplant recipients survived the 6-month follow-up period. At this time, duplex sonography and angiography revealed patent anastomoses in all animals. Increases in volumetric flow rates and vascular collateralization were observed in allografts, as compared with replanted joints (100+/-16 ml/min vs. 31+/-15 ml/min at 6 months after transplantation). Bone fusion at the graft-host interface was verified by fluorography in all animals at 3 months after transplantation. Six months after transplantation, microradiographies and computerized tomographies revealed spongialization of the cortical bone and filling of the medullary space by trabecular bone in transplanted joints. Such alterations were not detectable in replanted joints. Chondrocyte viability exceeded 80% in all but one transplanted joint. Lymphocyte infiltration of synovia and arterial walls was detected in all transplanted joints, suggesting the presence of chronic rejection. Weight-bearing capacity recovered in all replanted animals (weight-bearing index before transplantation: 0.499+/-0.080; 6 months after transplantation: 0.38+/-0.16) but only in two of four transplanted animals (weight-bearing index 6 months after transplantation: 0.37, 0.28, and 0.00). CONCLUSIONS: These data demonstrate the potential of joint grafting and the critical dependence of allotransplantation on the control of rejection.