Hypercoagulable abnormalities and postoperative failure of arterial reconstruction.

OBJECTIVES: To determine whether preoperative hypercoagulable abnormalities are independent risk-factors for the failure of arterial reconstruction in leg ischaemia. METHODS: Sixty consecutive patients were studied before, and for 1 year following, elective peripheral revascularisation. Antithrombin III, protein C and protein S levels, and tests for lupus anticoagulant were performed preoperatively, and then repeated on the first and third postoperative days and after 1 and 6 months. Heparin-associated thrombocytopenia was also investigated if there was a postoperative fall in platelet count greater than 100 x 10(9)/l. RESULTS: Forty-six (77%) procedures were performed for critical ischaemia and 15 (25%) involved infrapopliteal reconstruction. The nature of surgery or accepted risk factors for occlusion were comparable between the 40 (67%) patients with patent reconstructions at 1 year and the 20 (33%) who had suffered failure. Preoperative hypercoagulable abnormalities were detected in 21 (35%) patients, with a three times greater incidence in those whose reconstructions failed (65% vs. 20%, p < 0.01), and in 11 of 12 patients suffering early (within 1 month) occlusion. The lupus anticoagulant was more frequently detected when prosthetic grafts were already present (p < 0.05) and carried a positive predictive value for reocclusion of 67% (p < 0.01). All three postoperative deaths occurred in patients with low protein S levels before surgery. CONCLUSIONS: Hypercoagulable abnormalities are common prior to arterial revascularisation and are independently associated with subsequent failure.

Hypercoagulable states in patients with leg ischaemia.

Hypercoagulable states are found in up to 10 per cent of patients with a history of unexplained venous thrombosis. To investigate the prevalence in arterial thrombosis, thrombophilia screening was performed on 124 patients who had previously undergone lower-limb revascularization, 45 claudicants and 27 controls. Of the patients who had undergone revascularization 40 per cent had a hypercoagulation abnormality (low levels of protein C, protein S and antithrombin III or presence of the lupus anticoagulant) in comparison with 27 per cent of claudicants and 11 per cent of controls (P < 0.01). Furthermore, patients who had suffered reocclusion after revascularization were significantly more likely to have a hypercoagulation abnormality than those who had not (P < 0.05), even if the occlusion had occurred more than 6 months previously. Lupus anticoagulant was the abnormality most frequently detected and, like low protein C levels, was found only in patients with peripheral vascular disease. It appears that hypercoagulable states are common in patients with arterial disease and may predispose to failure of revascularization.

CT and MR findings in parameningeal leukaemic masses.

This study presents the clinical and imaging findings in seven patients with parameningeal leukaemic masses: four adults with granulocytic sarcoma and three children with soft tissue masses from acute lymphoblastic leukaemia. Computed tomography and magnetic resonance imaging were helpful in detecting these masses and in showing their extent. Magnetic resonance was particularly valuable in demonstrating abnormal bone marrow in the adult patients with granulocytic sarcoma. Computed tomography was valuable in demonstrating leukaemic relapse in the children when examination of CSF or bone marrow showed no evidence of leukaemia.