Congenital absence of the inferior vena cava: a rare risk factor for idiopathic deep-vein thrombosis.

Congenital absence of the inferior vena cava (AIVC) is a rare vascular defect, commonly reported as a fortuitous finding. The presence of AIVC in patients with DVT is underestimated because AIVC cannot be detected by compression B-mode ultrasonography. By use of computed tomography, we diagnosed four cases of AIVC in young patients with idiopathic DVT over a 5 year period. Based on the occurrence of DVT in patients below 30 years in our area during the same period, we estimate that AIVC is present in about 5% of cases of DVT in young patients. Computed tomography or angiography should be used for the diagnosis of idiopathic DVT in young patients.

Prediction of postoperative deep-vein thrombosis.

Prediction of patients at sufficiently high risk of postoperative deep vein thrombosis (DVT) to indicate perioperative antithrombotic prophylaxis usually employs only clinical risk factors. Studies of preoperative and/or postoperative haemostatic tests in the prediction of postoperative DVT are reviewed. In general, the results support the biological concept of a preoperative and postoperative prothrombotic tendency in patients who develop DVT. However, the clinical utility of such tests is unproven; so at present they cannot be advocated for routine preoperative or postoperative screening.

Free protein S deficiency is a risk factor for venous thrombosis.

A recent study suggests that protein S deficiency is not a risk factor for venous thrombosis. Since this unexpected finding would have important clinical implications if confirmed, we performed a case-control study with the aim to determine the prevalence of protein S deficiency in patients with thrombosis and in healthy individuals taken from the general population and the relative risk of thrombosis in protein S-deficient patients. Free protein S concentration was measured in 327 consecutive patients with at least one venous thrombotic episode and in 317 age- and sex-matched control individuals. Different normal reference ranges were obtained and adopted for men and women. Protein S deficiency was found in 3.1% (95% CI: 1.5-5.2) of patients and in 1.3% of controls (95% CI: 0.3-2.8). Ten patients and 4 control subjects had protein S deficiency, which determined a relative risk of thrombosis (sex- and age-adjusted odds ratio) of 2.4 (95% CI: 0.8-7.9). When men and women were analyzed separately, the risk was 5.0 (95% CI: 0.6-43.6) and 1.6 (95% CI: 0.4-6.7) respectively. PS-deficient men had more thrombotic episodes than women and later in life. Multivariate analysis established that sex was an independent determinant of the number of episodes, as was age, while PS deficiency was not. However sex and PS deficiency status were both determinants of age at first thrombotic episode.

[Thrombophilia in patients with venous thromboembolism]. / Trombofilia en pacientes con tromboembolismo venoso.

PURPOSE: To assess the incidence of congenital and acquired thrombophilia and to analyse the clinical characteristics of a group of patients with high risk criteria for thrombophilia. PATIENTS AND METHODS: Two hundred and eighty-five consecutive patients seen at the anticoagulant outpatient clinic of the Oviedo Central Hospital between 1987 and 1993 were evaluated. The patients had to meet one or more of the following: 1) venous thrombosis (VT) under 45 years of age; 2) repeat VT; 3) family history of VT; 4) unusual VT location (mesenteric, brain, etc.). The study was performed 4 to 7 months after the first acute episode and at least one month after suppression of anti-vitamin K treatment. The following test were carried out: blood cell counts, basic coagulation tests (APTT, PT, TT, RT and fibrinogen), lupus-like anticoagulant detection, with and without platelet extract, diluted tissular thromboplastin inhibition test, antibodies, anticardiolipin, liver and kidney functional screen, cholesterol, HDL, triglycerides and glycaemia. The venous occlusion test after 20-minute stasis was used for the global fibrinolysis study. The statistical evaluation was performed with the SPSS programme. RESULTS: Biologic alterations were present in 98 patients (35%), 12% corresponding to congenital thrombophilia and 23% to acquired thrombophilia. The study was normal in 187 patients (65%). Of the patients with congenital thrombophilia, 4.9% had protein C (PC) deficit, 3.4% protein S (PS) deficit, and 2.4% antithrombin III (AT-III) deficit. Of the patients with acquired thrombophilia, 4.5% had antiphospholipid antibodies and 18% had impaired fibrinolysis. Of all the data analysed, the patient history was found of scarce predictive value as to the risk for thrombophilia. Significant differences were found for family history of VT (p < 0.0005) and for the association of more than one criteria for inclusion (p < 0.001). CONCLUSIONS: No conclusions could be drawn from this study regarding the prophylactic attitude in patients with congenital abnormalities or anti-phospholipid antibodies. It is recommended to assess in such patients PC, PS and AT-III activities.

[Interruption of the infra-renal inferior vena cava with azygos continuation. Case report]. / Interruption infra-rénale de la veine cave inférieure avec continuation azygos. A propos d'un cas.

The authors report a case of congenital interruption of the inferior vena cava with azygos continuation with a deep venous thrombosis of the left lower extremity. It is a rare congenital abnormality which is most of the time asymptomatic. However such an abnormality may be a problem in case of cardiac catheterization or thoracic surgery.

Thromboembolic manifestations and congenital factor V deficiency: a family study.

A case of congenital factor V deficiency is reported. Despite this defect in blood coagulation, the patient had experienced recurrent thrombophlebitis and was referred to us because of deep venous thrombosis of the lower limbs associated with pulmonary embolism. Both functional and immunological assays documented a deficiency of factor V (12 and less than 10%, respectively). The available family members were investigated and the same defect was found in 2 brothers of the propositus, who also suffered from thrombotic diseases (recurrent thrombophlebitis and myocardial infarction). The propositus has been treated with long-term oral anticoagulant therapy, no hemorrhagic complications or thrombotic recurrences being recorded in 2 years' time.

Congenital abnormal plasminogen, Frankfurt I, a cause for recurrent venous thrombosis.

A new abnormal plasminogen, Frankfurt I, has been identified in the plasma of a 42 year-old male patients who had recurring thromboses, thrombophlebitis and pulmonary embolism since his age of 29. Reduced functional and also slightly reduced antigen plasminogen concentrations were found in both the proposituts and his mother. Plasmin generation rates carried out by Streptokinase and Urokinase were also abnormal. The plasmin generated was very unstable in the absence of stabilizing ligands and/or substrates. Crossed immunoelectrophoresis of the purified Frankfurt I revealed a peak with normal size and shape, but displaced with respect to normal Glu-plasminogen toward the anode. Isoelectric focusing followed by zymography on an agarose-fibrin plate proved this observation but did not indicate a separation of the normal from the abnormal plasminogen molecular species, also, fewer bands were found in the abnormal plasminogen isozyme pattern. Kinetic studies of Frankfurt I Glu-plasminogen and plasmin showed that most of the functional abnormality is related to absence of active sites in half of the molecules.

[Congenital abnormalities related to coagulation and the fibrinolytic system in patients with vein thrombosis of the lower extremities].

Plasma concentrations of antithrombin III (AT III), plasminogen (Plg), and protein C (PC) were assayed in 28 patients with venous thrombosis of lower extremities without distinct underlying disorders. Three abnormalities were found in 5 cases (17.8%) in relation to coagulation and fibrinolytic system (3 with congenital AT III deficiency, one each with dysplasminogenemia and congenital PC deficiency). In the patients with either one of these abnormalities, characteristic features of thrombosis are summarized as follows; 1. early onset of clinical symptoms. 2. high frequency of superficial vein thrombosis. 3. high recurrence rate. 4. high frequency of pulmonary embolism.

Deficiency of protein C in congenital thrombotic disease.

A family with a history of recurring thrombosis was studied to determine if a plasma protein deficiency could account for the observed disease. Protein C levels in plasma were determined immunologically using the Laurell rocket technique. The propositus, his father, and his paternal uncle, who are severely affected, had 38-49% of normal levels of protein C antigen, whereas unaffected family members had normal levels. There was no familial deficiency of antithrombin III and plasminogen. Because activated protein C is a potent in vitro anticoagulant enzyme and an in vivo profibrinolytic agent, it is suggested that the recurrent thrombotic disease in this family is due to an inherited deficiency in protein C.

[Renal venous thrombosis in infants of diabetic mothers (author's transl)]. / Trombósis venosa renal en hijos de madre diabética.

Six cases of renal venous thrombosis in infants of diabetic mothers, out of a series of 61 infants under two months old affected of R.V.T. (9.8%), are reported. The clinical, metabolic and histopathological features of these cases are discussed, as well as the different etiological theories that exist in the literature. An etiopathogenic hypothesis that maintains a similarity with the theory that explains the origin of R.V.T. in classical cases, is suggested. Prophilactic attitudes in order to prevent R.V.T. by a control of diabetes in the pregnant and close control of the newborn in the 10 first days of life, are pointed out.

Congenital nephrotic syndrome and renal vein thrombosis in infancy.

Three of the four cases of the nephrotic syndrome in infancy described show the typical clinical and pathological features of the commonly termed congenital nephrotic syndrome, and two of them abnormal immunoglobulins. Two of the infants were siblings. The placental abnormalities and renal electron microscopic changes are reported and are believed to be involved in antigen-antibody reactions. The literature is reviewed and the possible aetiology of these lesions is discussed. The fourth case is considered to be due to thrombosis of the inferior vena cava and renal veins, an extremely rare cause of the nephrotic syndrome in infants.