腓肠肌与深静脉血栓课件.pptVIP

* This diagram illustrates the suPTErficial， deep and PTErforating veins outlining the presence of. valves * This diagrams illustrate both normal venous return and compromised venous return * * There is a very strong association between pulmonary embolism (PE) and deep vein thrombosis (DVT): - 90% of pulmonary emboli are the results of DVT - A recent study showed that 82% of patients with acute PE had detectable DVT at the time PE was diagnosed. - Silent PE occurs in more than 50% of patients with symptomatic proximal DVT. As the venous clot in the leg grows it extends along the vein. DVT can develop into a chronic condition in which damage to the valves in the veins results in swelling of the leg, pain and venous hypertension (known as post-thrombotic syndrome - PTS) Parts of the clot can also detach, travelling in the blood to block vessels in the lungs, subsequently causing pulmonary embolism (PE). If less than 50% of the pulmonary circulation is blocked, symptoms are generally limited to shortness of breath or are absent altogether. Very large emboli, however, can cause massive blockage of the pulmonary circulation and rapidly lead to death. 1. Pesavento R, Lusiani L, Visona A, et al. Prevalenza di embolia polmonare clinicamente silente nella trombosi venosa profonda degli arti inferiori. Minerva Cardioangiologica 1997;45:369-375. 2. Girard P, Musset D, Parent F, Maitre S, Phlippoteau C, Simmonneau G. High prevalence of detectable deep venous thrombosis in patients with acute pulmonary embolism. Chest 1999;116:903-908. * * Two complications of VTE, post-thrombotic syndrome and pulmonary hypertension, deserve further description. Post-thrombotic syndrome, or PTS, is characterised by oedema, pain, induration, and impaired viability of subcutaneous tissues.1 Severe PTS can lead to intractable, painful venous leg ulcers - as shown here – that require ongoing nursing and medical care.2 In extreme cases, recurrent ulcerations may ultimately require lower