Israel Medical Association Journal

Endovascularly retrieved clots may be a potential resource for diagnosing stroke etiology. This method may influence secondary prevention treatment. We measure thrombin activity eluted by serially washing clots. We concluded that an assay measuring the change in thrombin in clots retrieved during acute stroke endovascular thrombectomy procedures may serve as a diagnostic marker of the origin of the clot. The suggested mechanism for these differences may be the clot location before its retrieval, with high blood flow causing thrombin washout in atherosclerotic clots, in contrast to atrium appendage low blood flow retaining high thrombin levels.

Background: Recurrent miscarriages are associated with a high prevalence of thrombophilia. Use of a calibrated automated thrombogram (CAT) can serve as a universal test for thrombophilia.

Objectives: To examine whether thrombin generation measured by CAT is elevated during the first trimester in women with unexplained recurrent miscarriages.

Methods: This study comprised 25 pregnant women with recurrent pregnancy loss referred for thrombophilia screening and treated with low-molecular-weight heparin (LMWH). Thrombin generation parameters were measured in women who had miscarriages or live births and who were diagnosed as positive or negative for thrombophilia.

Results: Of the pregnancies, 76% resulted in live birth and 24% ended in miscarriages. Among the women, 76% were positive for thrombophilia. Thrombin generation parameters between pregnancies that ended in miscarriage compared to live births were not significantly different, and CAT parameters failed to predict pregnancy outcome. Although the CAT parameters demonstrated a trend toward a hypercoagulable state in women with thrombophilia, there was no statistical significance (P > 0.05).

Conclusions: Women with unexplained pregnancy loss demonstrated similar thrombin generation in the first trimester, regardless of the pregnancy outcome. CAT parameters failed to predict pregnancy outcome in women with recurrent unexplained pregnancy loss. Our results should be interpreted with caution due to the small number of participants.

Background: Venous thromboembolic diseases are treated initially with low molecular weight heparin followed by oral coumarins.

Objectives: To investigate an orally available direct thrombin inhibitor for the acute treatment of venous thromboembolism as well as for prophylaxis of recurrent events.

Methods: The direct thrombin inhibitor ximelagatran was compared with subcutaneous LMW[1] heparins followed by oral warfarin in a double-blind randomized prospective multicenter trial in patients with acute VTE[2]. A pharmacokinetic study was performed in the VTE patients. For assessing the prevention of recurrent VTE, double-blind prospective randomized studies were conducted as follows: a) ximelagatran compared to warfarin for 6 months, and b) prolonged anticoagulation of ximelagatran vs. placebo for 18 months after termination of 6 months coumarin therapy.

Results: Two dose-finding studies and the pharmacokinetic analysis of ximelagatran in acute VTE were completed. About 2,500 patients were randomized to investigate 2 x 36 mg ximelagatran versus 2 x 1 mg/kg body weight enoxaparin followed by warfarin. The study hypothesized that the efficacy was equal in both treatment regimens for recurrent VTE documented by objective methods. The second study, with 1,234 patients, aimed to demonstrate a reduced incidence of recurrent thromboembolic events documented by objective methods after 18 months of treatment with 2 x 24 mg ximelagatran daily compared to placebo.

Conclusion: These large-scale clinical trials will soon yield the results of the comparison between oral ximelagatran and subcutaneous LMW heparin for treatment of acute VTE, and of warfarin for prophylaxis of recurrent events for 6 months and for a prolonged prophylaxis for another 18 months.

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[1] LMW = low molecular weight

[2] VTE = venous thromboembolism

Background: Both diagnostic and therapeutic options in the management of iatrogenic false aneurysms have changed dramatically in the last decade, with surgery being required only rarely.

Objective: To describe our experience, techniques and results in treating pseudoaneurysms at a large medical center with frequent arterial interventions. We emphasize upper limb lesions.

Materials and Methods: We reviewed the data of all consecutive patients diagnosed by color-coded duplex Doppler between August 1992 and July 1998 as having upper limb and lower limb pseudoaneurysms (mainly post- catheterization). We accumulated 107 false aneurysms (mainly post- catheterization lesions): 5 were upper limb lesions and 102 were groin aneurysms.

Results: In the lower limb cases 94 of the 102 lesions were not operated upon (92.1%). Seventy lower limb cases were treated non-operatively by ultrasound-guided compression obliteration with a 95.7% success rate (67 cases). Two cases were treated by  percutaneous thrombin injection (2%) and 23 by observation only (22.5%). Altogether 12 patients underwent surgery (11.2%): 4 upper extremity and 8 lower extremity cases. None of the lower limb group suffered serious complications regardless of treatment, but all five upper limb cases did, four of them necessitating surgical intervention. Three of the five upper limb cases had a grave outcome with severe or permanent or neurological damage.

Conclusion: Most post- catheterization pseudoaneurysms can be managed non-surgically. False aneurysms in the upper extremity are rare, comprising less than 2% of all lesions. However, upper extremity pseudoaneurysms present a potentially more serious complication and require early diagnosis and prompt intervention to minimize the high complication rate and serious long-term sequelae. Prevention can be achieved by proper puncture technique and site selection, and correct post-procedure hemostatic compression with or without an external device. Some upper limb lesions are avoidable if the axillary artery is not punctured.