Reflective Anamnesis

In view of his enormous and wide-ranging contribution to scientific medicine, it is hardly surprising that we can fault some of Virchow's ideas retrospectively. For instance, although he renamed 'phlebitis' as 'thrombosis', and knew about the mar-gination of leukocytes, he denied the process of leukocyte migration. He believed, at least in the 1840s and 1850s, that platelets were leukocyte debris. And although he appreciated that oxygen is involved in thrombogenesis, his attempts to expound a relevant mechanism were garbled. Neither was he impressed or convinced by Pasteur's germ theory of disease, though he did predict the discovery of bacterial toxins. No doubt, as for most of us, his opinions grew more inflexible and perhaps intolerant as he aged. His writing style became overblown and rhetorical, perhaps because of his increasing involvement in politics. But the magnitude of his scientific achievements renders these shortcomings insignificant by comparison.

In the field of thromboembolism alone, he proved that Cruveilhier's 'pulmonary phlebitis' results invariably from the metastasis of emboli produced as, and from, thrombi in peripheral veins. Although this now seems a commonplace, we have to appreciate the 10 years of outstanding experimental work that established it and disproved the conclusion of the great Cruveilhier. Virchow described the structure of thrombi in unprecedented detail, showing - inter alia - that they are always anchored tenuously but unequivocally to the venous endothelium (of inner valve pockets). He articulated a 'triad' of histological and macroscopic differences between 'clot' and 'thrombus', proved that oxygen is required for thrombus/embo-lus formation and that oxygen is supplied by the flowing blood, and taught that thrombi do not form in static blood. Among the terms that he added to our vocabulary, thrombus, embolus and ischaemia are particularly relevant to this book. His achievements in several other areas of medicine were of comparable significance.

Although many of his opinions were not pertinent to the theme of this book, one was significant: he doubted that either the mechanistic or the pathophysiological/ vital-materialist approach alone would afford a satisfactory philosophical or meth odological basis for scientific medicine. And although he was personally attuned to his own 'pathophysiological' viewpoint as indicated in Cellular Pathology, he argued strongly that the two contemporary philosophical positions were complementary, and that both were required for complete understanding.

What he did not achieve was an explicit account of the aetiology of DVT. Yet his writings provided the basis and the inspiration for his successors to seek the causal factors in thrombogenesis, and several attempts were made during the 50 years or so following his death. However, not until the middle of the 20th century were such attempts ascribed, wrongly, to Virchow himself.

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