Recurrent Pulmonary Embolism (*1) ...

Recurrent Pulmonary Embolism (*1)

The main objective in treating venous thromboembolism with heparin is to resolve into the risk of further pulmonary emboli. Despite adequate anticoagulant treatment, returns accur. [1-8] Can anticoagulation failure be lay opened before these recurrences occur? Usual laboratory way s to monitor anticoagulation failure do not always reliably predict the having recourses [9,10] and then the moot points arise from a lack of conclusive evidence about which patients are at a higher risk of the having recourses Several authors have hinted that the finding of a free-floating thrombus onward venography may represent a substantial risk of embolism. [11] Others have reported a higher anticoagulation failure rate in cancer patients with venous thrombosis. [12] There have been a number of prospective studies aimed at detecting factors which lead to return despite heparin therapy, but principally of them do not include a inferior lung scan routinely performed to compare against the baseline scan. Additionally, there have not been prospective studies looking specifically at the part of venography in predicting these recurrences

We have prospectively studied a consecutive series of patients with venous thromboembolism (both pulmonary embolism and venous thrombosis), searching for patients who unfold recurrences of pulmonary embolism despite heparin therapy. Furthermore, several points of clinical and laboratory information were measured, and the risk of returns was assessed.

MATERIAL AND METHODS

Since January 1985 145 consecutive patients in our hospital were diagnosed as having acute venous thromboembolism. All had objective criterions to confirm the diagnosis: venous thrombosis was confirmed with ascending x-ray venography in all patients; pulmonary embolism with a high-probability ventilation and perfusion lung scan venographic documentation of venous thrombosis onward lower extremities. Only those patients having an adequate course of heparin therapy were included, and therefore, ten of these patients were not included (clinically massive pulmonary embolism, four; previous abnormalities onward blood coagulation tests, two; intracerebral hemorrhage, one; digestive bleeding, one; hematoma, one; thrombocytopenia, common Additionally, another 14 patients were exclud because of adverse tenors of heparin therapy: digestive bleeding, seven; hematuria, four; thrombocytopenia, two; retroperitoneal hematoma, one

A total of 121 patients recorded into the study; they were 64 men and 57 women aged 21 to 86 years, mean 64 A total of 38 patients had clinically apparent pulmonary embolism, and 83 patients had astute venous thrombosis on lower limbs. Each patient received eight days of intravenous heparin therapy. Then oral warfarin therapy was begun. A baseline lung scan was obtained initially in each patient, whether the original diagnosis was pulmonary embolism or venous thrombosis. Repeat chest roentgenograms and lung scans were obtained routinely at eight days after heparin was started, and at any other time that signs or symptoms indicated.

The primary trial endpoint was a finding of confirmed, clinically apparent returning pulmonary embolism during the first eight days of heparin therapy. In addition, laboratory evidence of subclinical pulmonary embolism was categorized as symptomless recent perfusion lung scan defects seen at the repeat investigation in portions previously well perfused (according to Gallus et al. manners [13]).

All lung scans were obtained with a standard gamma camera. Pulmonary perfusion imaging was performed using [sup.99m.Tc-macroaggregated albumin injected intravenously with the patient supine. Imaging included six standard projections (anterior, posterior, right and left laterials, and right and left posterior obliques). Ventilation imaging was performed with [sup133Xe] All images were obtained in the posterior projection. The ventilation-perfusion studies were interpreted in accordance with the criteria of Biello et al, [14] by means of two staff physicians who had no knowledge of either the clinical history or venogram findings. They examined the perfusion studies to determine whether there were single or multiple perfusion deficiencys and they noted the sizes of the largest flaws to anatomic divisions of the lung Then they compared the major perfusion destitutions with the ventilation defects, and the lung scan obtained eight days after heparin started with the baseline scan. When interpretation of the couple readers differed, the readers reviewed the case together and came to a consensus opinion.

Biplanar ascending conventional venograms allowed the classification of iliofemoral thrombi as occlusive or free-floating when associated with a 5 cm or greater proximal part of thrombus outlined by radiopaque contrast material. [11] Furthermore, the stage of closeness of the aforesaid thrombus was determined at the distance in centimeters from the thrombus proximal close to the vena cava bifurcation into the iliac veins.