[The neoartery, myth or reality? Study of 79 explanted arterial prostheses]

This study represents the third stage of a personal study on the long term fate of reconstruction and arterial restoration materials presented to the Academie de Chirurgie. 79 explanted prostheses were studied. First of all by an in depth histological study (8 cases selected from 70 reinterventions carried out before 1980), and then by a more complete protocol: scanning electron microscopy, resistance testing, programmed differential calorimetry, X-ray diffraction and biochemical analysis (71 reinterventions carried out after 1980). Our findings agree with the studies of R. Guidoin. With the exception of structural manufacturing defects or defects related to surgical manipulation, mechanical fatigue in a Dacron (PET) arterial prosthesis is inevitable: on average by the 7th to 10th year, a prosthesis looses one half of its mechanical resistance. The covering tissue, like that of the external capsule, which has poor mechanical properties, cannot compensate for prosthetic deterioration which may be considered to be complete by the 25th year. Knitted arterial prostheses, especially aortic, more rapidly undergo dilatation than woven prostheses which are much more resistant. On the other hand, the poor compliance of the latter compared with the recipient artery, perhaps favorises late anastomotic rupture. At internal capsule or pseudo-intimal level, endothelium is never present, but rather there is a permanent turnover with a variable time course, the mechanisms of which are poorly understood (role of prostaglandins?). Rather than a neo-artery, the vascular surgeon is only capable of producing an imperfect arterial tube, fragile from many points of view, and having an evolution which remains poorly understood.