Effect of ticlopidine on blood loss, platelet turnover and platelet deposition on prosthetic surfaces in patients undergoing aorto-femoral bypass grafting

Sixty patients in whom a prosthetic aorto-femoral bypass graft was inserted were pretreated with ticlopidine (250 mg b.i.d.) or placebo in a double-blind study. Blood loss and transfusion need were higher in ticlopidine treated patients. Platelet survival was partially corrected and platelet deposition on prosthetic surfaces was inhibited with ticlopidine. The study suggests that ticlopidine does not increase excessively the bleeding risk during peripheral vascular surgery and that the antiplatelet drug may have beneficial effects in the early phase after insertion of prosthetic vascular graft.

Assessment of the patency of deep leg veins with duplex

To evaluate the accuracy of venous duplex, results obtained in 101 patients are compared with venography. A first group consisted of 48 patients with clinically suspected deep vein thrombosis. In 30 of them a positive duplex scan was obtained and all had subsequently a positive venography. Eighteen patients with a normal duplex scan had a normal venography. Another group of 53 patients were tested preoperatively for varicose vein surgery. No obstruction of the venous system was withheld with duplex but 3 patients had an old thrombosis on venography. Thus duplex is a highly reliable method to detect proximal thrombosis in clinically suspected patients but detection of late sequelae of thrombosis may be more difficult.

Prophylactic antiplatelet therapy in peripheral arterial disease

Prophylactic therapy with antiplatelet drugs aims to improve both the general prognosis of patients and the local progression of peripheral arterial disease. A recent meta-analysis of 28 trials revealed that the proportional risk reduction in serious vascular events is similar to that in cardio- and cerebrovascular disease. A decreased incidence of vascular complications was also found in a meta-analysis of 4 trials with ticlopidine, and a recent Swedish study [Swedish Ticlopidine Multicentre Study (STIMS)] confirmed that long term ticlopidine reduces both mortality and cardio- and cerebrovascular morbidity. There is also evidence that aspirin (acetylsalicylic acid) and ticlopidine retard progression of atherosclerosis and the occurrence of its thrombotic complications, in patients with arterial disease of the legs. Meta-analysis has recently indicated that antiplatelet agents reduce the incidence of graft occlusion in arterial surgery. These drugs are also traditionally prescribed after percutaneous revascularisation procedures. The efficacy of antiplatelet therapy in patients with peripheral arterial disease emphasises the role of platelets in this condition.

Bilateral carotid artery occlusion: clinical presentation and outcome

In a 4-year period, 17 patients were diagnosed as having bilateral carotid artery obstruction on ultrasonic duplex examination. Twelve had been referred because of recent neurological symptoms and the remaining 5 during cardiac or peripheral vascular work-up. Three patients had a completely silent occlusion of their two carotid arteries. Cardiac and/or peripheral vascular symptoms were present in 11 subjects. Mean follow-up was 28 months. No further strokes occurred. The 3-year cumulative stroke-free survival by life-table analysis was 75%. Myocardial infarction was the cause of death in 2 of 4 patients. For some patients with bilateral carotid artery occlusion, the clinical outcome is better than anticipated.

Ridogrel, a combined thromboxane synthase inhibitor and receptor blocker, decreases elevated plasma beta-thromboglobulin levels in patients with documented peripheral arterial disease

The combination of thromboxane synthase inhibition with thromboxane receptor antagonism has been shown to result in a strong inhibition of platelet aggregation and a prolongation of the bleeding time (Gresele et al., J. Clin Invest 1987; 80: 1435-45). Ridogrel is a single molecule that efficiently achieves both inhibitions in human volunteers. The present study was performed in patients with obstructive peripheral arterial disease and elevated plasma beta-thromboglobulin levels. Patients were treated with either 2 x 300 mg ridogrel or 2 x 300 mg placebo per day for 2 1/2 days, according to a double blind randomised parallel design. Plasma beta-thromboglobulin decreased significantly throughout active treatment starting within 2 h after administration; serum and urinary immunoreactive TxB2 levels and urinary 11-dehydro-TxB2 excretion were significantly lower and serum PGE2 and 6-keto-PGF1 alpha levels significantly higher with ridogrel; no changes were observed in the placebo-treated group. In conclusion this study demonstrates a reduction of platelet activation in vivo by ridogrel.

[Angioplasty using a Nd:YAG laser with a sapphire probe]

Laser angioplasty with Sapphire Contact Probes coupled to a Nd:YAG laser followed by balloon angioplasty was performed in 30 patients with 26 femoropopliteal and 4 iliac artery occlusions. Mean length of the occlusions was 4.5 +/- 1.6 cm with a mean duration of occlusion of 7.06 +/- 6.18 months. Initial angiographic success was obtained in 25/30 (83%) procedures, including 3/4 successes in the iliac artery (75%) and 22/26 successes in the femoropopliteal artery (84%). Reason for failure was perforation in 2 patients, and subintimal passage of the probe in 2, and heavy calcification of the lesion in 1 patient. Early rethrombosis in 3 patients reduced the primary success rate to 73%. Peripheral emboli necessitating surgical intervention occurred in 2 patients. Of the 22 recanalized arteries 21 remained patent with a mean follow-up of 8.4 +/- 3.3 months. It remains to be determined whether the angiographic and clinical short and long term success rate of "laser assisted balloon angioplasty" will be greater than after thrombolysis or conventional balloon angioplasty.

Protein C deficiency associated with venous thromboembolism

Protein C deficiency has been reported to be associated with a high risk for thromboembolism. We report three patients with protein C deficiency: one suffered from left renal vein thrombosis, another from recurrent venous thrombosis of the legs complicated by pulmonary embolism and the third from an extensive thrombosis of the splanchnic veins with partial Budd-Chiari syndrome. We discuss the unusual sites of venous thrombosis in protein C deficient patients, the factors which may act as thrombotic trigger and the strategy of long-term prevention.

Thrombosis in particular organ veins

Renal vein thrombosis in early infancy is a complication of dehydration and prolonged hypotension. The onset is usually acute and the most common clinical signs are uni- or bilateral frank masses, hematuria, proteinuria and thrombocytopenia. In most cases, with conservative management, the late outcome is favorable. In the adult, renal vein thrombosis is often a silent complication of the nephrotic syndrome, the hypercoagulability of which may be an important factor in the pathogenesis of the thrombosis. Clinically, the presentation of a sudden complete occlusion is that of severe abdominal and lumbar pain with hematuria and loss of function of the kidney that suffers hemorrhagic infarction. Physical examination often reveals an enlarged kidney. With gradual occlusion, renal function is preserved. The initial diagnostic approach is with ultrasound studies and computed tomography; definitive diagnosis is established by renal venography or by selective renal arteriography. In general, a conservative approach including the use of anticoagulant treatment is preferred to surgical intervention. Priapism is a persistent painful penile erection due to ischemic or non-ischemic causes; therapeutic intracavernosal injection of papaverine is becoming the most common cause. In early and mild stages, aspiration of blood from the corpora cavernosa supplemented with intracavernosal irrigation with alpha-stimulating agents is the procedure of first choice; in late and severe ischemia, a shunt procedure may become necessary. Hepatic vein thrombosis occurs in association with a number of conditions considered predisposing factors including the use of oral contraceptives. The clinical picture may be that of an acute illness with abdominal pain, hepatomegaly, ascites and hepatic failure as well as early death. More often, the onset is insidious with slowly developing ascites and wasting. For the diagnosis, hepatic scintigraphy may be helpful but, at present, ultrasonography, computed tomography and magnetic resonance scanning are procedures of choice. There is, as yet, no adequate treatment. A fatal outcome may be prevented by surgical decompression of the congested liver and, in recent years, liver transplantation has been employed. Portal vein thrombosis, in children, is usually considered a complication of umbilical sepsis or a result of a congenital abnormality of the portal vein. In adults, the most frequent causes are hepatic cirrhosis and neoplasia. Clinically, there may be a sudden appearance of ascites with resolution in a symptom-free interval until the onset of other features of portal hypertension occur. Currently, ultrasound real-time imaging supplemented with Doppler capability, computed tomography and magnetic resonance scanning provide the necessary diagnostic information. Variceal hemorrhage is often the first major complication requiring treatment.(ABSTRACT TRUNCATED AT 400 WORDS)

Multicenter pilot study of the efficacy and safety of systemic rt-PA administration in the treatment of deep vein thrombosis of the lower extremities and/or pelvis

Patients with symptoms of deep vein thrombosis for less than 10 days were treated with a standard dose of heparin. In the open label phase of the trial, 11 patients received 100 mg rt-PA on the first day and 50 mg on the subsequent day in an 8 hour infusion. In the double-blind phase, 8 patients were randomized to the same rt-PA regimen, 6 patients to an infusion of 50 mg rt-PA over 8 hours on days 1 and 2, and 7 patients to placebo infusions. The mean change in venographic score in all patients treated with rt-PA plus heparin is -3.8 units compared to -0.6 units in patients treated with heparin alone (p = 0.06). Bleeding complications classified as major were noted in 8/25 patients receiving the combined treatment.

Femoro-popliteal artery thrombolysis with intra-arterial infusion of recombinant tissue-type plasminogen activator--report of a pilot trial

Recombinant tissue-type plasminogen activator (rt-PA) was infused at a rate of 10 mg/h into 50 thrombosed femoral and popliteal arteries. Patency was restored in 43 but a secondary angioplasty led to 2 reocclusions and in 3 patients early rethrombosis occurred. A favourable clinical result was thus obtained in 38 patients (76%). Thirteen bleeding complications occurred in 10 patients, mainly haematomas at puncture sites. One patient required blood transfusion for gastro-intestinal bleeding from a previously unknown ulcer. The angiographic recanalisation rate in 16 patients who received a slower infusion of rt-PA (5 or 3 mg/h) was 94% and the clinical success rate in this series was 81%. However, the incidence of bleeding complications was not decreased by the slower infusion rate. The data obtained confirm the feasibility of rt-PA thrombolysis in peripheral arterial thrombosis and warrant a comparative study with streptokinase.

Thromboembolism and antithrombotic therapy in peripheral arterial disease

Atherosclerosis complicated by thromboembolism is the main cause of obstructive arterial disease in the legs. Two studies from West Germany suggest that antiplatelet drugs may slow the progress of atherosclerosis in leg arteries and prevent occlusive thrombosis under some circumstances. The same agents may also reduce the risk of rethrombosis after successful vascular repair in the femoropopliteal region; in one trial, aspirin decreased the incidence of reocclusion after thromboendarterectomy and, in another, the combination of aspirin and dipyridamole was effective after bypass with synthetic material. Antithrombotic drugs are used in most centers after percutaneous transluminal angioplasty, but there is no definite evidence for their need. Thus, it appears that in contrast to cardiac and cerebrovascular disease, few efforts have been made to determine the true value of antithrombotic therapy in peripheral arterial disease. The management of acute thromboembolism in the legs requires a multidisciplinary approach. Depending on the type (embolic or thrombotic), length and localization of the arterial occlusion, surgical (embolectomy, thromboendarterectomy, peripheral bypass surgery) or nonsurgical (systemic fibrinolysis or local thrombolytic therapy with or without balloon angioplasty) treatment is preferred. The importance of nonsurgical therapeutic approaches may become even greater in elderly patients with a poor operative risk. This review discusses the available therapeutic modalities in acute and chronic peripheral thromboembolic arterial disease.

Placebo-controlled, double-blind, two-centre trial of ketanserin in intermittent claudication

The effects of ketanserin, a serotonin antagonist, were studied in 37 patients with intermittent claudication in a double-blind placebo-controlled, trial done in London and Leuven. 40 mg ketanserin taken orally three times a day for 4 months was associated with a clear-cut inhibition of serotonin-induced platelet aggregation but no changes were observed in pain-free and maximum walking distance on a treadmill, in ankle/arm Doppler systolic blood pressure ratio, or in reactive hyperaemia after 3 min of ischaemia. In contrast, the placebo group had increases in both pain-free and maximum walking distance (p less than 0.05).

Arterial obstructive disease of the lower limbs in the elderly: is angiography required?

A retrospective study of 61 hospitalized elderly patients with peripheral arterial disease revealed that a large majority of them presented with restpain and/or skin defects and gangrene. A palpable popliteal artery was usually indicative of severe distal disease and a poor outlook for revascularisation. In the other patients, angiography was required to clearly delineate good from poor candidates for arterial repair. Yet, only one third of the patients submitted to angiography could ultimately benefit from vascular reconstruction.

[Gastrointestinal hemorrhage in an aged subject with an aortic prosthesis]

An old patient with aortic prosthetic graft was admitted to the hospital with an upper gastro-intestinal bleeding. The prosthesis was seen protruding into the afferent loop of a previous gastrectomy. Despite immediate surgery to remove the aortic graft and to close the fistula, the patient died suddenly on the first postoperative day. A herald bleeding two months previously had passed without suspicion of a possible aorto-enteric fistula. The pathogenesis and clinical appearance of aorto-enteric fistulae are reviewed and the attitude in the elderly with aortic prostatic graft and upper gastro-intestinal blood loss is discussed.

Platelet survival in patients with angiographically diseased and normal coronary arteries

Platelets may contribute to the pathogenesis of atherosclerosis and to the complications of coronary artery disease. Therefore, platelet kinetics were studied in 69 patients with angiographically documented coronary artery disease and in 16 patients with a normal coronary angiogram. Platelet survival time was calculated from the decay of radioactivity after injection of 51Cr-labeled autologous platelets. None of the mathematical models used was able to discriminate between the two patients groups. No correlation existed between survival time and extent of the arterial disease. Patients with a high serum cholesterol did not exhibit an enhanced platelet consumption. Thus, these studies do not support the idea that turnover is enhanced in patients with coronary artery disease as compared to those with normal coronary arteries.

Sources of calcium used during alpha 1- and alpha 2-adrenergic contractions in canine saphenous veins

Experiments were performed to determine the role of intra- and extracellular Ca2+ during contractions of canine saphenous veins evoked with 'alpha 1'- and 'alpha 2'-adrenergic agonists. After incubation in Ca2+-free medium for 45 min, noradrenaline, clonidine and phenylephrine caused contractions, reaching a maximal amplitude rapidly and then declining to a lower stable level within 6 min. The maximal amplitude amounted to about 10% of the response to the agonists in physiological saline containing Ca2+ ions. After a previous exposure to one of the alpha-adrenergic agonists in Ca2+-free medium, no peak response was observed when the preparations were exposed to any of the agonists a second time. The stable smaller contractions which followed the peak response could however be repeated after a previous exposure to one of the agonists. In normal physiological salt solution (PSS), iproveratril depressed the maximal response to all three agonists to about 60% of the control value. However, the shift of the median effective dose (ED50) to the right was larger for clonidine than for the other two agonists. Noradrenaline, clonidine and phenylephrine (all at 10(-5) M) increased the uptake of 45Ca. Iproveratril reduced this increased uptake of 45Ca. Noradrenaline, clonidine, guanfacine and phenylephrine augmented the efflux rate of 45Ca. After exposure to one of the agonists, noradrenaline caused no or only a moderate increase of the efflux rate of 45Ca. The present experiments indicate that in the dog's saphenous vein: (1) alpha 1- and alpha 2-adrenergic activation cause both influx of Ca2+ ions and release of intracellular Ca2+; (2) the source of the intracellular Ca2+ is the same; (3) the mechanism underlying the influx of extracellular Ca2+ ions into the smooth muscle cells, to judge from the inhibiting effect of iproveratril, is most likely to be the same.

Modulation of the concentration of noradrenaline at the neuro-effector junction in human saphenous vein

We studied the importance of neuronal and extraneuronal uptake and of the pre-junctional alpha-adrenergic feed-back mechanism for the junctional noradrenaline concentration in the human saphenous vein. All major metabolites of the enzymatic breakdown of noradrenaline were detected in the overflow of superfused veins loaded with [3H]-noradrenaline. The efflux of 3,4-dihydroxyphenylglycol (DOPEG) was drastically reduced in preparations labelled after neuronal uptake blockade indicating its neuronal origin; the other metabolites are formed extraneuronally since they behaved distinctly differently from DOPEG under several experimental conditions. Extraneuronal uptake followed by enzymatic breakdown removes the same amount of noradrenaline from the biophase during nerve activity as that diffusing intact out of the tissue, whereas neuronal uptake appears only half as effective since the overflow of intact noradrenaline increases by only 48% in the presence of desmethylimipramine (DMI). However, in preparations mounted for isometric tension recording, neuronal uptake blockade potentiated contractions to alpha-adrenergic activation, emphasizing the functional importance of the neuronal disposition mechanism. By contrast, no evidence was found for a hydrocortisone-sensitive extraneuronal uptake compartment, suggesting that extraneuronal removal may have little, if any, functional importance. During nerve stimulation, yohimbine increased the amount of labelled noradrenaline present in the superfusate, while exogenously added noradrenaline decreased it in the presence of cocaine. Thus, prejunctional alpha-adrenoceptors can modulate the junctional concentration of neurotransmitter in the human saphenous vein.

Transluminal angioplasty: late results sustained by digital intravenous subtraction angiography

Digital intravenous subtraction angiography (DIVSA) appears to be a technique of minimal invasiveness and high accuracy in the follow-up of patients after percutaneous angioplasty (PTA) allowing correct angiographic evaluation in more than 96% of the cases. Correlation between clinical and angiographic findings seems to be excellent. Of the controlled intravenous examinations performed in 54 successful PTA procedures 75% appeared patent after 10 to 30 months, constituting 52% of the original attempts.

Controlled trial of suloctidil in intermittent claudication

Forty-five patients with intermittent claudication were first treated with placebo tablets for 3 months and then randomly allocated to double-blind therapy with either suloctidil or placebo for 6 months. Walking distance improved significantly in both groups during the 3 months of placebo treatment. During the 6 months of double-blind treatment with a further significant improvement occurred only in the placebo group when all patients were analyzed. However, when patients who stopped for reasons unrelated to claudication such as angina and exhaustion during repeated walking tests were eliminated, only suloctidil-treated patients improved significantly. The evolution of leg flow and distal pressure was similar in the two treatment groups whether all legs or only legs with abnormal flow and pressure values were considered. By contrast, when the analysis was limited to legs with claudication pain, a significant improvement occurred only in the suloctidil-treated group. These findings suggest that suloctidil may improve the claudication symptoms of patients with chronic arterial obstructive disease and in particular the perfusion of legs experiencing claudication pain. However, the clinical significance of this improvement appears limited.