Percutaneous interventions for pulmonary embolism

Venous thromboembolism and pulmonary embolism (PE) is the third most common cardiovascular disease and a leading cause of death in the US. There are many risk factors related to PE. Traditional treatments are anticoagulation, systemic thrombolysis, and surgical thrombectomy. More recently, several minimally invasive procedures were introduced, which includes catheter-directed thrombolysis, percutaneous embolectomy, embolus fragmentation techniques, pulmonary artery stent placement or association of two or more of those techniques. In the present study the Authors review the role of the different techniques for the treatment of PE, and provide some guidelines and indications for treatment. The most popular devices and techniques are described in detail, and the efficacy of the techniques is discussed.     

Dextran prophylaxis of fatal pulmonary embolism

Thromboembolic prophylaxis with dextran 70 was given routinely to patients undergoing major surgery from 1970 to 1972 and from 1975 to 1977, using slightly different dosages. During 1968 to 1970 and 1972 to 1974, no routine prophylaxis was given. During the 4 respective 2-year periods studied, the following number of postoperative fatal pulmonary emboli (FPE) were verified at autopsy: 16 (no prophylaxis); 6 (dextran); 19 (no prophylaxis); and 4 (dextran). The incidence of FPE in relation to major operations was 35/5,094 (0.69%) without prophylaxis, and 10/4,881 (0.20%) with prophylaxis,p < 0.001. The autopsy rate was 93.4% in postoperative deaths. Adherence to prophylaxis was 88 ± 5%. Routine prophylaxis with dextran 70 during surgery is, therefore, effective against fatal pulmonary embolism. Furthermore, it is easy to perform, lacking many of the practical disadvantages of oral anticoagulants and heparin.     

外科手术后肺动脉栓塞的诊治

肺动脉栓塞(Pulmonary Embolism,PE)是西方国家常见疾病,也是手术后常见的并发症。据近年流行病学调查,美国每年PE新发病例数约60万人,每年有6万人死亡,是疾病死亡的第三位原因,仅次于肿瘤和心肌梗塞,其中约1/5发生于手术后,占手术后死亡总数的15％～25％。我国PE发病可能少于西方国家,但绝不是少见病。术后发生PE,涉及外科各个领域,如骨科,普通外科,泌尿外科,心胸外科,神经外科及妇产科、某些介入治疗等,尤其是下肢骨关节手术,发生率可达50％。随着近年来对PE病因学、诊断学和治疗学等研究的不断深人,其死亡率和致残率有望进一步下降。本文就目前外科术后发生PE及其诊治作一综述。     

Dextran in the prophylaxis of pulmonary embolism

Dextran is a plasma volume expander which has antithrombotic effects. Some of these effects may be nonspecific and due to hemodilution and venous flow improvement. However, dextran also has specific antithrombotic effects that cause a temporary change in the structure and function of Factor VIII (antihemophilic globulin), which results in a decrease in platelet aggregability and thrombus stability. Intravenous dextran therapy has no marked effect on the incidence of small, early postoperative thrombi as detected by¹²⁵Iodine-fibrinogen, but it produces a significant decrease in the incidence of thrombi that can be diagnosed phlebographically or clinically. The most marked effect of dextran is on pulmonary emboli, and particularly on fatal pulmonary emboli as seen at autopsy, where it produces about a fivefold decrease in incidence. It is concluded that the antithrombotic properties of dextran are particularly useful in decreasing the incidence of postoperative pulmonary emboli.

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Résumé Le Dextran est un expanseur plasmatique qui possède une activité antithrombotique. Certains de ses effets sont peut-être non-spécifiques, résultant de l'hémodilution ou de l'amélioration du débit veineux. Mais le Dextran a aussi un effet antithrombotique spécifique: il modifie temporairement la structure et la fonction du facteur VIII (globuline antihémophile), ce qui réduit la capacité d'agrégation des plaquettes et la stabilité du thrombus. L'administration intraveineuse de Dextran modifie peu la fréquence des petites thromboses postopératoires précoces (celles qui sont détectées par le test au fibrinogène marqué à l'iode 125); mais elle réduit de façon significative la fréquence des thromboses qui sont diagnostiquées par la clinique et la phlébographie. L'effet le plus net est la diminution du nombre d'embolies pulmonaires, et surtout des embolies mortelles: les contrôles autopsiques montrent que cette réduction est de l'ordre de 80%Les propriétés antithrombotiques du Dextran sont donc particulièrement utiles dans la prévention des embolies pulmonaires postopératoires.

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Supported by grants from the Swedish Medical Research Council (B77-17X-00759-12A).     

Warfarin prophylaxis to prevent mortality from pulmonary embolism after total hip replacement

Between 1970 and 1987, 3000 total hip replacements were performed at the University of California at Los Angeles, and all patients were given warfarin prophylactically, in conjunction with early postoperative elevation of the lower limb in balanced suspension and the application of elastic hose. Since 1973, the first dose of warfarin has been given on the night of the operation, and the prothrombin time has been maintained between sixteen and eighteen seconds. A pulmonary embolism occurred after fourteen (0.5 per cent) of the 3000 operations. It was never fatal. Bleeding occurred after forty-four operations (1.5 per cent). The effectiveness of the protocol of the University of California at Los Angeles was demonstrated in a large number of patients over a seventeen-year period. Since 1974, the protocol has included closer monitoring of the prothrombin time. After 2595 hip replacements that were done between 1974 and 1987, the rate of pulmonary embolism was 0.2 per cent and the rate of bleeding complications was 1.0 per cent. However, recently a higher incidence of bleeding complications (2.3 per cent) has been noted after non-cemented total hip (stem-type) replacement.     

Low-dose warfarin prophylaxis to prevent symptomatic pulmonary embolism after total knee arthroplasty

Pulmonary embolism poses a risk to patients undergoing total knee arthroplasty. The selection of an appropriate prophylaxis agent and its implementation have been influenced by decreased duration of hospital stay and the pressures of cost containment. The purpose of this study was to determine the inpatient and outpatient pulmonary embolism rates, the number of days required to attain the target level of anticoagulation, and complications associated with the use of a low-dose warfarin prophylaxis protocol after primary and revision total knee arthroplasty. Between 1984 and 1993, there were 815 primary and revision total knee arthroplasties that received low-dose warfarin prophylaxis at our institution. The average time to attainment of the target level of anticoagulation was 3 days. The average duration of warfarin prophylaxis was 12 days. Overall, there were a total of three symptomatic pulmonary embolisms (0.3%; 95% confidence interval, 0.08%–1.1%). There were eight (1%) symptomatic deep vein thromboses (all distal). There were two deaths (0.3%), but neither one was secondary to a pulmonary embolism. Seventeen knees (2.5%) developed a hematoma after surgery, and two of these patients required drainage of the knee. Low-dose warfarin prophylaxis is safe and effective in preventing symptomatic pulmonary embolism after total knee arthroplasty.     

Hydroxychloroquine sulfate prophylaxis for pulmonary embolism for patients with low-friction arthroplasty

Hydroxycholoroquine sulfate has been administered for prophylaxis against pulmonary embolism following total hip arthroplasty. A significant reduction was observed in the rate of fatal emboli, with relatively few and minor side effects, on daily doses of 1200 mg.     

Acute pulmonary embolism: a current surgical approach

Acute massive pulmonary embolism has a high mortality rate despite advances in diagnosis and therapy. Thrombolysis and catheter embolectomy have recently shown various degrees of failure and adverse effect. Surgical embolectomy has now been liberalised for haemodynamic stable patients with right ventricular dysfunction. We report our surgical experience in the last ten years including massive and sub-massive pulmonary embolism. A retrospective review of charts of all patients undergoing pulmonary embolectomy at our institution over the last ten years was performed. Patients were followed up until December 2005, end point of our study. Between March 1995 and December 2005, 21 patients underwent pulmonary embolectomy. Fourteen patients had a massive pulmonary embolism and were in cardiogenic shock (group A). Seven patients had a sub-massive embolism and were haemodynamically stable with right ventricular dysfunction (group B). In group A, 43% of patients survived and were discharged from the hospital. In group B, all the patients survived and were discharged from the hospital. After a follow-up of 57+/-12 months no late death linked to pulmonary embolism was observed. Our approach by initial surgical embolectomy improved outcome in sub-massive PE. Rescue embolectomy for very compromised patients remains a current treatment for massive PE. Furthermore, surgical embolectomy in haemodynamically stable patients is an immediate and definitive treatment for PE, with excellent long-term results. Keeping in mind that thrombolysis and catheter embolectomy have varying degrees of failure and risk, we propose surgical embolectomy in (sub)massive pulmonary embolism as an alternative procedure, or even as a primary treatment.     

Thrombosis and coagulation: deep vein thrombosis and pulmonary embolism prophylaxis

Venous thromboembolism (deep venous thrombosis and pulmonary embolism, VTE) is a common complication in surgical patients and is the primary cause of preventable deaths in hospitalized patients. Despite well-known risk factors, VTE prophylaxis is frequently not practiced according to recommended guidelines.Patients can readily be stratified according to their risk of perioperative VTE, and mechanical and pharmacologic prophylactic regimens can be tailored to their individual risk. Pharmacologic VTEprophylaxis should be the standard of care in most clinical settings given its ease of administration, low risk, and cost-effectiveness.     

Application of cava-filter for surgical prophylaxis of pulmonary thromboembolism

Results of treatment of 148 patients, in whom deep veins thrombosis of v. cava inferior (VCI) system had occurred, were analyzed. Cava-filter (CF) was applied in 50 patients. CF "Osot" and temporary CF-thrombextractor were implanted for pulmonary thromboembolism (PTE) prophylaxis. Temporary CF-thrombextractors were implanted in 41 (66%) patients, the current CF "Osot"--in 21 (44%), the temporary one "Osot"--in 21 (44%), temporary CF with subsequent change for current one--in 12 (19%). The PTE recurrence was not observed, the VCI thrombosis had occurred after CF implantation in 3.2% of observations.     

Successful thrombolysis for massive pulmonary embolism after pulmonary resection

We report the successful use of thrombolysis for acute massive pulmonary embolism 2 days after right lower lobectomy for bronchial adenocarcinoma. Pulmonary angiography revealed extensive clot unsuitable for surgical embolectomy. A bolus infusion of recombinant tissue plasminogen activator produced an immediate improvement in the patient’s hemodynamic state. There was substantial blood loss requiring the transfusion of 21 units of blood over the postoperative period. The patient made a successful recovery and remained well at 1 year.     

Hydroxychloroquine in prophylaxis of pulmonary embolism following hip arthroplasty

Two thousand one hundred and forty four patients received Plaquenil (hydroxychloroquine sulphate) prior to total hip arthroplasty; the drug was continued until the patient was fully mobile. Fatal emboli (confirmed by postmortem) occurred in 0.28% and non-fatal emboli (diagnosed clinically) occurred in 4.15%. This was a statistically significant improvement over the overall results of all previous prophylactic measures used in this unit. The results of Plaquenil are significantly better than the most effective agent previously used in this unit, namely, Dindevan (phenindione). There were no deaths and no serious gastrointestinal or genitourinary bleeding. Allergic rashes occurred in 18 patients (0.8%), temporary blurring of vision in 6 (0.3%), and minor gastrointestinal upsets, including nausea, vomiting and minor bleeding in 12 (0.6%).