The local plasminogen activator response was predominantly within the thrombus itself. Increased t-PA activity was additionally found in distant veins but was reduced in the vessel wall adjacent to the thrombus. This is the first report to show that u-PA activity is increased within organizing thrombus in vivo and that most of the t-PA activity is localized to a monocyte infiltrate.

ObjectiveAccurate prediction of abdominal aortic aneurysm (AAA) growth in an individual can allow personalised stratification of surveillance intervals and better inform the timing for surgery. The authors recently described the novel significant association between flow mediated dilatation (FMD) and future AAA growth. The feasibility of predicting future AAA growth was explored in individual patients using a set of benchmark machine learning techniques.MethodsThe Oxford Abdominal Aortic Aneurysm Study (OxAAA) prospectively recruited AAA patients undergoing the routine NHS management pathway. In addition to the AAA diameter, FMD was systemically measured in these patients. A benchmark machine learning technique (non-linear Kernel support vector regression) was applied to predict future AAA growth in individual patients, using their baseline FMD and AAA diameter as input variables.ResultsProspective growth data were recorded at 12 months (360 ± 49 days) in 94 patients. Of these, growth data were further recorded at 24 months (718 ± 81 days) in 79 patients. The average growth in AAA diameter was 3.4% at 12 months, and 2.8% per year at 24 months. The algorithm predicted the individual's AAA diameter to within 2 mm error in 85% and 71% of patients at 12 and 24 months.ConclusionsThe data highlight the utility of FMD as a biomarker for AAA and the value of machine learning techniques for AAA research in the new era of precision medicine.

The vessel wall is the site of synthesis and regulation of the fibrinolytic system, and this delicate process is overwhelmed by occlusive thrombosis in veins. The endothelium may or may not survive thrombus formation, but has strong powers of regeneration, and is subsequently vital to the process of recanalizing the vessel. The endogenous fibrinolytic response to venous thrombosis is not well delineated but appears to involve both the newly formed endothelium within and beneath the organizing thrombus, together with an increase in tissue plasminogen activator synthesis or storage in distant uninvolved veins. The further use of thrombus models in which the endothelium is not definitely damaged should enable greater understanding of its role. Immunocytochemistry and in situ hybridization may be helpful in defining some of the unanswered questions.

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Aetiological factors in super®cial dorsal penile vein thrombosis include trauma, vigorous sexual activity, pelvic tumours and a distended bladder 1,2. Isolated penile vein phlebitis was originally described in 1958 3 as a variant of Mondor's disease, which is a more generalized super®cial venous thrombosis of the chest wall.