[Prevention of postoperative thrombo-embolism by heparin/dihydroergotamine (author's transl]

Joint 2022 European Society of Thoracic Surgeons and The American Association for Thoracic Surgery guidelines for the prevention of cancer-associated venous thromboembolism in thoracic surgery

BACKGROUND

Venous thromboembolism (VTE), which includes deep vein thrombosis and pulmonary embolism, is a potentially fatal but preventable postoperative complication. Thoracic oncology patients undergoing surgical resection, often after multimodality induction therapy, represent among the highest risk groups for postoperative VTE. Currently there are no VTE prophylaxis guidelines specific to these thoracic surgery patients. Evidenced-based recommendations will help clinicians manage and mitigate risk of VTE in the postoperative period and inform best practice.

OBJECTIVE

These joint evidence-based guidelines from The American Association for Thoracic Surgery and the European Society of Thoracic Surgeons aim to inform clinicians and patients in decisions about prophylaxis to prevent VTE in patients undergoing surgical resection for lung or esophageal cancer.

METHODS

The American Association for Thoracic Surgery and the European Society of Thoracic Surgeons formed a multidisciplinary guideline panel that included broad membership to minimize potential bias when formulating recommendations. The McMaster University GRADE Centre supported the guideline development process, including updating or performing systematic evidence reviews. The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used, including GRADE Evidence-to-Decision frameworks, which were subject to public comment.

RESULTS

The panel agreed on 24 recommendations focused on pharmacological and mechanical methods for prophylaxis in patients undergoing lobectomy and segmentectomy, pneumonectomy, and esophagectomy, as well as extended resections for lung cancer.

CONCLUSIONS

The certainty of the supporting evidence for the majority of recommendations was judged as low or very low, largely due to a lack of direct evidence for thoracic surgery. The panel made conditional recommendations for use of parenteral anticoagulation for VTE prevention, in combination with mechanical methods, over no prophylaxis for cancer patients undergoing anatomic lung resection or esophagectomy. Other key recommendations include: conditional recommendations for using parenteral anticoagulants over direct oral anticoagulants, with use of direct oral anticoagulants suggested only in the context of clinical trials; conditional recommendation for using extended prophylaxis for 28 to 35 days over in-hospital prophylaxis only for patients at moderate or high risk of thrombosis; and conditional recommendations for VTE screening in patients undergoing pneumonectomy and esophagectomy. Future research priorities include the role of preoperative thromboprophylaxis and the role of risk stratification to guide use of extended prophylaxis.

Joint 2022 European Society of Thoracic Surgeons and The American Association for Thoracic Surgery guidelines for the prevention of cancer-associated venous thromboembolism in thoracic surgery

BACKGROUND

Venous thromboembolism (VTE), which includes deep vein thrombosis and pulmonary embolism, is a potentially fatal but preventable postoperative complication. Thoracic oncology patients undergoing surgical resection, often after multimodality induction therapy, represent among the highest risk groups for postoperative VTE. Currently there are no VTE prophylaxis guidelines specific to these thoracic surgery patients. Evidenced-based recommendations will help clinicians manage and mitigate risk of VTE in the postoperative period and inform best practice.

OBJECTIVE

These joint evidence-based guidelines from The American Association for Thoracic Surgery and the European Society of Thoracic Surgeons aim to inform clinicians and patients in decisions about prophylaxis to prevent VTE in patients undergoing surgical resection for lung or esophageal cancer.

METHODS

The American Association for Thoracic Surgery and the European Society of Thoracic Surgeons formed a multidisciplinary guideline panel that included broad membership to minimize potential bias when formulating recommendations. The McMaster University GRADE Centre supported the guideline development process, including updating or performing systematic evidence reviews. The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used, including GRADE Evidence-to-Decision frameworks, which were subject to public comment.

RESULTS

The panel agreed on 24 recommendations focused on pharmacological and mechanical methods for prophylaxis in patients undergoing lobectomy and segmentectomy, pneumonectomy, and esophagectomy, as well as extended resections for lung cancer.

CONCLUSIONS

The certainty of the supporting evidence for the majority of recommendations was judged as low or very low, largely due to a lack of direct evidence for thoracic surgery. The panel made conditional recommendations for use of parenteral anticoagulation for VTE prevention, in combination with mechanical methods, over no prophylaxis for cancer patients undergoing anatomic lung resection or esophagectomy. Other key recommendations include: conditional recommendations for using parenteral anticoagulants over direct oral anticoagulants, with use of direct oral anticoagulants suggested only in the context of clinical trials; conditional recommendation for using extended prophylaxis for 28 to 35 days over in-hospital prophylaxis only for patients at moderate or high risk of thrombosis; and conditional recommendations for VTE screening in patients undergoing pneumonectomy and esophagectomy. Future research priorities include the role of preoperative thromboprophylaxis and the role of risk stratification to guide use of extended prophylaxis. (J Thorac Cardiovasc Surg 2022;▪:1-31).

Prophylaxis Against Thromboembolism in Vascular Surgery

Thrombosis prophylaxis is indicated in vascular surgical patients for two general considerations: to prevent thromboembolism from the venous system and occlusion of reconstructed arterial vessels.

The purpose of this randomized, prospective study was to compare the effectiveness of low-dose heparin, heparin in combination with dihyder gotamine, and dextran-60 in the prevention of postoperative venous throm bosis and pulmonary embolism after vascular operations. In addition, any adverse effects of each medication on patency after arterial reconstruction was to be determined.

Prevention of deep vein thrombosis in neurosurgical patients: a prospective double-blind comparison of two prophylactic regimen

In a prospective, randomized, double-blind investigation of anticoagulant agents for prevention of deep vein thrombosis in patients undergoing operations at the lumbar-vertebral disc, 179 patients were randomly allocated to two groups. 87 patients received a fixed combination of low-molecular weight heparin 1,500 U-aPTT plus dihydroergotamine 0.5 mg (LMWH/DHE) once a day and additionally one injection of placebo per day, 92 patients received a fixed combination of sodium heparin 5,000 U plus dihydroergotamine 0.5 mg (HDHE) twice a day. Treatment was initiated two hours preoperatively in both groups and continued for at least seven days. Deep vein thrombosis (DVT), detected by the 125Iodine-labelled fibrinogen uptake-test, occurred in four patients treated with LMWH/DHE and in three patients with HDHE. In all seven patients phlebography was performed, confirming the diagnosis of DVT in one patient of the LMWH/DHE group and in two patients of the HDHE group, only. No increased bleeding was found in either group. Especially no neurological complications caused by epidural bleeding were observed. We therefore recommended to treat routineously all patients undergoing operations at the vertebral disc with antithrombotic agents. The advantages of the once daily regimen with low-molecular weight heparin include better patients' acceptance and less nursing time.

Anticoagulants in the prevention of venous thromboembolism

For 50 years, the key to successfully preventing venous thrombosis (VT) or pulmonary embolism (PE) among high-risk patients has been the judicious use of anticoagulants: first through full doses of oral anticoagulants and more recently through low-dose heparin prophylaxis. Low-dose heparin has become the standard of comparison for other preventive methods, since it is relatively safe and simple, its ability to prevent approximately 65% of the subclinical VT found by leg scanning after elective general surgery is well known, and recent meta-analysis of the many pertinent published clinical trials (large and small) strongly suggests a much greater benefit: a 65% reduction in the risk of postoperative death from major PE. In addition, there are trials that have also found low-dose heparin to be effective in general medical patients, although its value in this clinical setting is much less well documented. Although several effective approaches other than low-dose heparin are available, many of these tend to be either more cumbersome (intermittent external leg compression) or probably less powerful (graded pressure elastic stockings). There are situations where low-dose heparin prophylaxis fails, most obviously after orthopaedic surgery where the use of more complex regimens, including adjusted-dose heparin treatment and various schedules of warfarin prophylaxis, becomes appropriate. Recent progress has come from the intensive clinical exploration of various low molecular weight heparin fractions or fragments which appear to be effective after once daily administration to general surgical patients and show great promise of effectiveness and safety after hip surgery. The level of warfarin effect needed for VT prophylaxis has also been reinvestigated, with trials suggesting a need for less warfarin and a lower prothrombin time effect than was previously thought to be appropriate. Given that any attempts to minimize mortality from PE in hospital patients must rely on the widespread and systematic use of simple, safe, and cost-effective preventive methods, it is hoped that these advances will help move anticoagulant prophylaxis further out of the realm of clinical research and into that of common clinical practice.

Preventive and therapeutic approach to venous thromboembolic disease and pulmonary embolism--can death from pulmonary embolism be prevented?

Venous thromboembolism produces chronic sequelae in the legs and occasional immediate mortality due to pulmonary embolism. Because it occurs in certain high risk situations (for example, after surgery) its prevention is a practical proposition. This has been attempted using many different approaches. Administration of low dose heparin with or without dihydroergotamine to enhance venous return has been one of the most widely tested regimens. There is little doubt that this can prevent, in many patient groups, postoperative deep venous thrombosis and fatal pulmonary embolism, with a low incidence of adverse reactions. Some particularly high risk postoperative patient groups (for example, those undergoing hip surgery) warrant more aggressive measures to prevent thrombosis. Surveys have shown that increasing use is being made of this approach, and it is hoped that all surgeons will adopt a policy that will reduce postoperative venous thrombosis and pulmonary embolism. A reduction in the incidence of venous thromboembolism in large acute myocardial infarction is achieved by low dose heparin, although early mobilization is important. In addition, many of the patients at risk merit full dose anticoagulation to prevent intracardiac thromboembolism. Established venous thrombosis is treated effectively by intravenous heparin, followed by warfarin to keep the prothrombin time at 1.2 to 1.5 times control, as assessed using rabbit thromboplastin; most patients need three months of treatment. Anticoagulation is warranted for pulmonary embolism, with fibrinolytic therapy reserved for patients with massive embolism and hemodynamic compromise. Embolectomy is a heroic measure, which may occasionally be lifesaving.

[Perioperative prevention of thromboembolism in gynecology]

Operative or postoperative deep vein thrombosis (DVT) occurs in about 10-30% of the patients undergoing gynecologic surgery, depending on the kind of operation and the presence of predisposing risk factors. Fatal pulmonary embolism is the direct and most severe complication of DVT in 8% of all patients in the postoperative period. DVT commonly results in circulatory insufficiency and ulcers of the lower extremities. The goal of effective prevention of DVT is achieved only by the use of drugs like coumarin, dextran, low dose heparin or low dose heparin-DHE. The therapeutic value of these medicaments and their side effects will be presented and new developments shortly discussed.

Low molecular weight heparin plus dihydroergotamine for prophylaxis of postoperative deep vein thrombosis

In a prospective, double-blind investigation of the prophylaxis of deep vein thrombosis (DVT) in patients undergoing elective major abdominal surgery, 269 patients were randomized into two groups. One hundred and thirty-two patients received a fixed combination of heparin sodium 5000 units plus dihydroergotamine mesylate 0.5 mg (H/DHE) twice a day and 137 patients received a fixed combination of low molecular weight heparin 1500 units plus dihydroergotamine mesylate 0.5 mg (LMWH/DHE) once a day as well as one injection of placebo per day. Treatment was initiated 2 h pre-operatively in both groups and continued for 7-10 days. The frequency of DVT determined by the 125I-labelled fibrinogen uptake test and phlebography was 10.3 per cent in patients receiving H/DHE and 10.4 per cent in those receiving LMWH/DHE. DVT of the femoral vein was detected in four patients of the H/DHE group and in none of the LMWH/DHE group. Intra- and postoperative blood loss did not differ significantly between both groups. Also no difference in the development of wound haematoma and injection site haematoma was found. While intra-operative volume substitution was comparable in both groups, significantly more patients under H/DHE prophylaxis received volume substitution during the postoperative phase. These results show that once-daily prophylaxis with the combination of low molecular weight heparin and dihydroergotamine is equally as effective and as safe as the twice-daily regimen using a combination of unfractionated heparin and dihydroergotamine in patients undergoing elective, major abdominal surgery. The advantages of the once-daily regimen of LMWH/DHE include greater patient acceptance, less nursing time and greater cost effectiveness, provided the new combination can be sold at a cost which maintains this advantage.

Prophylaxis of Postoperative Thromboembolism with Heparin-Dihydroergotamine Combination

The effect and safety of a fixed combination — 5000 iu of heparin + 0.5 mg of dihydroergotamine every 12 h subcutaneously (HDHE) versus 5000 iu of heparin every 8 h subcutaneously (LDH) for prophylaxis of postoperative venous thromboembolism was evaluated in a prospective randomized clinical trial involving 142 patients undergoing major abdominal surgery. Using the radiofibrinogen uptake test postoperative deep venous thrombosis was detected in 10% of 70 patients in the HDHE group and in 14% of 72 patients of the LDH group. Seven patients died. Neither fatal, nor contributory pulmonary emboli were found at autopsy. Pulmonary microembolism diagnosed with lung perfusion scintigraphy and chest radiography developed in three patients treated with LDH and in one patient treated with HDHE. Significantly more wound haematomas and injection site bruises were observed in the LDH group. The conclusion drawn was that the 12-hourly regimen of heparin with DHE was as effective in preventing venous thromboembosis as the 8-hourly heparin regimen. The lowering of the heparin dose significantly reduced both the number of wound haematomas and injection site bruising.

The pharmacokinetics and bioavailability of subcutaneously administered dihydroergotamine, heparin and the dihydroergotamine-heparin combination

Subcutaneously administered dihydroergotamine (DHE) becomes rapidly and completely available to the human systemic circulation, with peak plasma levels of 1.4-3.5 ng/mL/mg achieved in less than 1 h. The elimination of DHE from plasma is biphasic, t 1/2 alpha = 1h, t 1/2 beta = 4-5 h. DHE exhibits linear dose proportionality. Coadministration of heparin results in a statistically significant increase of 25% in the area under the plasma level/time curve for DHE (bioavailability). Coinjection of DHE and heparin in the same subcutaneous site furthermore causes a decrease in the rate of DHE absorption by 63%, resulting in delayed time to peak (by 110%) and reduced peak levels (by 15%) of DHE. In contrast, there is no effect by coadministered DHE on heparin pharmacokinetic parameters. Heparin peak plasma levels (0.3 I.U./mL by activated factor X, 0.1 I.U./mL by protamine titration with a 15,000 I.U. s.c. bolus) are achieved in 3.6 h. Pharmacokinetic analysis suggests that the subcutaneous route of administration provides only 19% of the bioavailable heparin that would be obtained following administration of an equipotent intravenous dose. DHE-heparin formulated for injection in combination demonstrates systemic availability identical to that of the two components injected separately, but with a reduced rate of absorption for the DHE component and a corresponding attenuation of fluctuations in steady state DHE levels.

[Thromboembolism prevention in surgical medicine: heparin or heparin-dihydroergotamine?]

This review summarizes clinical studies on prevention of venous thromboembolism by heparin or heparin and dihydroergotamine. Advantages and disadvantages of both drugs are described. The value of low-dose-heparin can no longer be seriously disputed. Up to now, however, there is no clear evidence that heparin-dihydroergotamine improves the efficacy and reduces the frequency of complications. The later drug is a new approach still under investigation.

The effect of dihydroergotamine and heparin on the incidence of thromboembolic complications following total hip replacement: a randomized controlled clinical trial

A randomized blind clinical trial was carried out to assess the effect of dihydroergotamine (DHE) alone and in combination with heparin on the incidence of thromboembolic complications of total hip replacement. It was found that a combination of DHE 0.5 mg and heparin 5000 units subcutaneously, given 8-hourly in separate injection sites, reduced the incidence of thromboembolic complications from 63 per cent in the untreated controls to 7.4 per cent in the treated group. This difference was highly significant. DHE alone produced a reduction in the incidence of thromboembolism but this reduction was not statistically significant. Blood loss was calculated using pre- and postoperative haemoglobin levels, taking into account the amount of blood transfused. It was found that the blood loss in the DHE/heparin-treated patients was identical to that in the untreated controls. The patients who received DHE alone had a significantly lower mean blood loss than the other two groups. It is concluded that this reduction in blood loss by DHE may be due to its venoconstrictor properties.

Dihydroergotamine and heparin or heparin alone for the prevention of postoperative thromboembolism in gynecology

The efficacy of combined dihydroergotamine and heparin (DHE-heparin) medication (2500 IU sodium heparin and 0.5 mg DHE, both given subcutaneously twice daily) or low doses of heparin (5,000 IU of sodium heparin given subcutaneously thrice daily) in preventing postoperative thromboembolic complications was investigated in a prospective, randomized trial in 125 patients over the age of 40 years undergoing elective major gynecological surgery. The I125-fibrinogen uptake test was used for the diagnosis of deep vein thrombosis. There was no statistically significant difference in the incidence of thromboembolism between the groups. Major bleeding occurred less often (p < 0.05) in the DHE-heparin group.