Thromboembolic Complications
Thromboembolic complications affect 1.3% to 6.4% of Crohn D es and Ulcer.Colitis patients (Fig. 11.104) (178). Both venous thromboembolism and arterial thrombosis develop. Arterial thrombosis, however, is rare, occurring most commonly following surgery. Extensive arterial thrombosis (179) occasionally occurs in UC patients. Portal vein, mesenteric vein, and hepatic vein thrombosis also associate with a high mortality.
View Figure FIG. 11.104. Portal vein thrombosis in a patient with a hypercoagulable state and inflammatory bowel disease. Cerebral venous thrombosis is an extremely rare complication of IBD with only a small number of cases reported in the literature. When it develops, the outcome is poor (180). In most instances, permanent neurologic sequelae or death results (179). Even young infants may develop central nervous system thrombosis (180). Thromboembolic episodes more commonly affect the deep peripheral veins or result in pulmonary emboli. The risk of thrombotic complications increases with disease activity or other precipitating events. In some series, 64% of patients have active disease at the time of thrombosis (172).
The thrombosis in IBD is generally considered to result from the presence of a hypercoagulable state. Other contributing factors include bedrest, toxemia, and surgical procedures. Hemostatic abnormalities include thrombocytosis, elevated fibrinogen, factors V and VII, vitamin K, and decreased protein C and S, factor XIII, and antithrombin III levels (172,181,182). Sixty-three percent of CD and 25% of UC patients demonstrate free protein S deficiency. Protein C deficiency also occurs. Protein C activity may return to normal on disease remission or following subtotal colectomy (183). Other abnormalities include the presence of fibrin microclots. Platelets circulate in an activated state in IBD, and the increased platelet activation and aggregation found in this disorder may contribute to the risk of systemic thromboembolism and mucosal inflammation secondary to ischemia. Circulating immune complexes contribute to the development of vasculitis (184), which then predisposes to thrombosis. Additionally, patients might have CMV infections that can precipitate localized clotting secondary to an endothelialitis.
ну вот к примеру можно и под таким углом зрения на проблему посмотреть 
Добавлено (2010-06-25, 10:26 PM)
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на фото представлены внекишечные проявления ВЗТК, вторая фото - поражение печени при НЯК( билиарный цирроз, ПСХ)
