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.     

Fixed combinations of low-molecular weight or unfractionated heparin plus dihydroergotamine in the prevention of postoperative deep vein thrombosis

A prospective, double-blind, randomized, controlled clinical trial compared the efficacy and safety of fixed combinations of low-molecular weight heparin or standard unfractionated heparin plus dihydroergotamine mesylate in the prevention of deep vein thrombosis in high-risk patients undergoing elective major abdominal surgery. Two hundred patients, with a mean age of 66.6 years and almost half with malignancy, were allocated to receive either 5,000 IU unfractionated heparin plus 0.5 mg dihydroergotamine mesylate twice daily or 1,500 IU low-molecular weight heparin plus 0.5 mg dihydroergotamine mesylate once daily together with one placebo injection per day. Treatment was commenced 2 hours preoperatively and continued for at least 7 days. The incidence of deep vein thrombosis, determined by radiolabelled fibrinogen uptake and phlebography, was 11 percent in the unfractionated heparin plus dihydroergotamine mesylate group and 11.4 percent in the low-molecular weight heparin and dihydroergotamine mesylate group. Neither these figures nor those for major proximal thrombi proved significantly different. Of the four parameters used to assess hemorrhagic complications, only the decrease in postoperative hemoglobin levels in the low-molecular weight and dihydroergotamine mesylate group reached statistical significance. These results indicate that once-daily prophylaxis with a combination of low-molecular weight heparin and dihydroergotamine is safe, effective, and convenient in high-risk patients undergoing major abdominal surgery.     

Dihydroergotamine/heparin in the prevention of deep-vein thrombosis after total hip replacement. A controlled, prospective, randomized multicenter trial

In a randomized, double-blind, placebo-controlled multicenter trial, the efficacy and safety of dihydroergotamine mesylate/heparin sodium as a prophylactic agent for deep-vein thrombosis were evaluated in 148 patients who were forty years old or more and who underwent total hip replacement. The incidence of venographically proved postoperative deep-vein thrombosis was 52 per cent in the placebo group and 25 per cent in the dihydroergotamine mesylate/heparin sodium group (p = 0.002). Proximal thrombi developed in only 5 per cent and extensive thrombi, in only 10 per cent of the patients who received dihydroergotamine mesylate/heparin sodium. In contrast, proximal thrombi and extensive thrombi developed in 19 and 25 per cent, respectively, of the patients in the placebo group (p less than 0.05). Adverse reactions in the two groups did not differ significantly: in the treatment group they consisted primarily of hematoma at the site of injection (9 per cent), hematoma at the wound (5 per cent), and excessive postoperative bleeding, and in the placebo group there was hematoma at the site of injection (3 per cent). It was concluded that the combination agent dihydroergotamine mesylate/heparin sodium was effective and safe prophylaxis against deep-vein thrombosis for the patients who underwent total hip replacement in this study.     

Dihydroergotamine and the thromboprophylactic effect of dextran 70 in emergency hip surgery

In a prospective randomized controlled trial treatment with a combination of dextran 70 and dihydroergotamine (DHE) was compared with the administration of dextran 70 alone as prophylaxis against postoperative thrombo-embolic complications in emergency hip surgery. Forty-five consecutive patients with a fractured hip entered the study. Twenty-one were randomized to prophylactic treatment with dextran 70 (group 1) and twenty-four patients received dextran 70 and DHE (group 2). Both regimens were initiated pre-operatively and the surgical and postoperative procedures were the same in the two groups. On the first and fourth postoperative day, Tc-plasmin scintigraphy of the lower extremities and pulmonary ventilation/perfusion scintigraphy were performed to detect any deep vein thrombosis (DVT) and/or pulmonary emboli. A total of 19 per cent of group 1 patients developed DVT and so did 25 per cent in group 2; this difference was not statistically significant. Of the detected DVT, 60 per cent were subclinical, and 7 per cent of the patients had minor pulmonary emboli, all of which were symptomless. No therapeutic difference could be demonstrated between the two regimens. A recent report claiming that adding DHE to the prophylactic administration of dextran 70 considerably reduces the incidence of postoperative DVT in emergency hip surgery is questioned.     

Prevention of thromboembolism in surgery

Thromboembolic complications are one of the most common complications in patients undergoing major surgery or conservative treatment in cast. The incidence of thromboembolic complications is the highest in orthopedic and trauma surgery. Stasis in the deep veins of the lower extremity, intimal damage and disorders in blood coagulation are important factors in the pathogenesis of deep vein thrombosis. The most important predisposing risk factors are age, previous thrombosis, varices and the combination of oral contraceptives and smoking. 50% of thrombosis begins intraoperatively and 80-90% in the first 3-4 days after operation. The incidence of thromboembolic complications was significantly reduced after introduction of low-dose heparin and heparin with dihydroergotamine in the perioperative regimen. Recently various investigations demonstrated that low-molecular-weight heparin (LMWH) is equally as effective as a low-dose heparin regimen in preventing postoperative thromboembolic complications. Our own management of prophylaxis of thromboembolic complications is presented. In a prospective pilot study 100 trauma patients were evaluated. 84 patients received LMWH plus dihydroergotamine (DHE), 12 patients heparin alone because of contraindications for DHE and 4 patients received a low dose continuous intravenous heparin prophylaxis because of high risk. Two deep vein thrombosis occurred, one in a patient with high risk prophylaxis and one in a patient with a subcutaneously heparin prophylaxis. No thromboembolic complications occurred in patients with LMWH + DHE prophylaxis.     

Efficacy and safety of low-molecular-weight heparin (CY216) in preventing postoperative venous thrombo-embolism: a co-operative study

The efficacy and safety of a low-molecular-weight (LMW) heparin fraction in preventing postoperative venous thrombo-embolism, was assessed in a double blind, randomly allocated trial, and in an 'open' study. Of 395 patients included in the double blind trial, 199 received unfractionated (UF) calcium heparin, and 196 the LMW heparin fraction. The data were analysed on an 'intention to treat' basis. The two groups were well matched for risk factors which could predispose to the development of venous thrombosis. Fifteen (7.5 per cent) of one hundred and ninety-nine patients receiving UF heparin, and five (2.5 per cent) of one hundred and ninety-six patients in the LMW heparin group developed DVT (P less than 0.05). There was no significant difference between the two groups in terms of excessive incisional or total blood loss during surgery, postoperative drainage or wound haematoma formation. Of 910 patients included in the 'open' study who received a single injection of LMW heparin every day, 30 (3.2 per cent) died during the postoperative period; in none of the autopsied patients were pulmonary emboli detected. Thirty-one (3.4 per cent) patients developed isotopic DVT; twenty-seven (2.9 per cent) were receiving prophylaxis at the time the DVT was diagnosed. Thirty-six (3.9 per cent) patients developed wound haematoma; twenty-five (12.4 per cent) of those were in the two hundred and one undergoing surgery for gynaecological conditions, and eleven (1.5 per cent) in the seven hundred and nine patients having general abdominal surgery. This difference is statistically significant (P less than 0.001). The results of a double blind trial indicate that a single daily injection of 1850 APTT units (7500 antifactor Xa units) of a LMW heparin is more effective than 10 000 APTT units of commercially available UF heparin in preventing postoperative DVT. The findings of the 'open' study suggest that this regimen also provides an effective prophylaxis against post-operative major pulmonary embolism.     

Thrombosis prophylaxis with low molecular weight heparin in total hip replacement

In a randomized prospective trial, the efficacy of low molecular weight heparin (LMWH) (Fragmin) and dextran 70 (Macrodex) in preventing deep vein thrombosis (DVT) in the legs was evaluated in 98 consecutive patients undergoing elective total hip replacement. The patients were randomly allocated to receive either 2500 anti-factor Xa units LMWH twice daily for 7 days, with the first dose given 2 h before surgery; or 500 ml dextran 70 twice during the day of operation, followed by a single infusion of 500 ml on the first and again on the third postoperative day. DVT was assessed by 125I-fibrinogen test for 2 weeks postoperatively, a positive test being followed by phlebography. DVT developed in 22 (45 per cent) of 49 patients receiving dextran 70 and in 10 (20 per cent) of 49 patients in the LMWH group (P less than 0.01). LMWH was thus statistically significantly better than dextran 70 in preventing DVT in the legs. It was not firmly established whether this benefit was also valid in the high ileofemoral region. Two patients with non-fatal pulmonary embolism were found in each group. Per- and postoperative blood loss and blood transfusion requirements were significantly lower in the LMWH group.     

Dextran/aspirin versus heparin/dihydroergotamine in preventing thrombosis after hip fractures

In a randomised trial we compared the effects of two different antithrombotic regimens on the incidence of venographically established deep venous thrombosis (DVT) in 83 patients undergoing surgery for fracture of the femoral neck. Group A received dextran 40 peroperatively plus 0.5 g aspirin a day beginning before operation and continuing for 10 days after. Group B received heparin calcium 5000 iu subcutaneously plus dihydroergotamine (DHE) 0.5 mg intramuscularly, given 8-hourly, beginning before operation and continuing for 10 days after. Two patients in Group A and three in Group B developed proximal DVT, while the incidence of all DVT was 33% in Group A and 29% in Group B, a difference which was not significant. Haemorrhagic complications were much more common in the dextran/aspirin group: the volume of drainage fluid, the number of patients transfused and quantity of blood transfused, and the drop in haemoglobin level were all significantly greater in Group A. We conclude that the DHE/heparin regime is preferable to dextran/aspirin because it is safer and no less effective.     

Operative venodilation: a previously unsuspected factor in the cause of postoperative deep vein thrombosis

Intraoperative venodilation in veins distant from the site of operation has been shown to occur in animals and has been directly correlated with focal venous endothelial damage. This exposure of subendothelial collagen could serve as initiation sites for thrombus formation. This study tests the hypothesis that human beings (1) significant operative venodilation occurs and that it correlates with postoperative deep venous thrombosis (DVT); (2) operative venodilation can be pharmacologically controlled; and (3) this control reduces the incidence of postoperative DVT. Twenty-one patients undergoing total hip replacement had their contralateral cephalic vein continuously monitored with modified ultrasonographic instrumentation, with a continuous on-line recorder graphing venous diameter. Patients were randomly assigned to receive 0.5 mg of dihydroergotamine and 5000 U of heparin (DHE/Hep) for prophylaxis or placebo, with investigators "blinded" Postoperatively, all patients underwent ascending phlebography. Patients in whom postoperative DVT developed (11) had a mean operative venodilation of 28.9% +/- 3.93%, and those in whom DVT did not develop (10) had a mean venodilation of 11.6% +/- 1.55% (p = 0.001). Only 17% (2/12) dilating less than 20% baseline diameter had DVT compared with 100% (9/9) dilating greater than 20% of baseline diameter (p = 0.002). Patients receiving venotonic agent DHE had significantly less venodilation and DVT (p less than 0.001) compared with patients receiving the placebo. Patients who had DVT and whose veins dilated greater than 20% were older than patients who did not have DVT and whose veins minimally dilated: p = 0.04 and p = 0.07, respectively. Although there was a trend toward increased venoconstriction in patients receiving DHE/Hep (p = 0.09), there was no correlation of venoconstriction with ultimate thrombotic outcome. Maximal venodilation occurs during handling of soft tissue (muscle), and this occurs significantly sooner than maximal venoconstriction, which occurs during bone manipulation. We conclude that excessive operative venodilation is a new and important etiologic factor that leads to postoperative DVT. Operative venodilation can be pharmacologically controlled with the venotonic agent DHE. The combination DHE/Hep reduces postoperative DVT by the reduction of operative venodilation in the presence of low doses of an anticoagulant. These findings offer a new approach for predicting postoperative DVT and an object rationale for developing effective prophylaxis.     

Unterschiedliche Wirksamkeit von zwei Präparaten mit niedermolekularem Heparin bei Patienten mit elektivem Hüftgelenksersatz

Zusammenfassung In einer offen-randomisierten, dreiarmigen Studie bei 105 Patienten mit elektivem Hüftge-lenksersatz wurde die Wirksamkeit and Verträglichkeit eines niedermolekularen Heparins, einer Kombination eines anderen niedermolekularen Heparins mit Dihydroergotamin und eines unfraktionierten Heparins verglichen. Die Wirksamkeit wurde mittels Radiofibrinogentest während der ersten 7 postoperativen Tage sowie mittels beidseitiger Phlebographie am 14./15. postoperativen Tag überprüft. Bei gleichguter Verträglichkeit der 3 Prophylaxeschemata ergab sich eine deutliche Über-legenheit der Kombinationsprophylaxe gegenüber dem reinen niedermolekularen Heparin. Während die Thromboserate unter der Kombinationsprophylaxe bei 22,9% lag, betrug sic unter niedermolekularem Heparin allein 50,0% (2 p=0,03) and fur unfraktioniertes Heparin 30,6%.

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Different effects of LMW-heparin on patients with total hip replacement

Summary In an open randomised trial 3 regimen of prophylaxis for deep vein thrombosis were compared in 105 patients undergoing elective hip arthroplasty. One part of the patients received one injection daily of a low molecular weight heparin, another part was treated with one injection of a combination containing a different type of low molecular weight heparin + dihydroergotamine per day and a third part of the patients received 3 applications of 5000 IU unfractionated heparin per day. The frequency of DVT determined by the ¹²⁵iodine-labelled fibrinogen uptake test and phlebography was 22.9% in patients receiving the combination and 50.0% in those receiving the low-molecular weight heparin alone. The difference was statistically significant with 2 p = 0.03. The incidence of DVT in patients receiving unfractionated heparin was 30.6%. No difference in the development of bleeding complications was found between the three treatment groups.

     

Prophylactic efficacy of low-dose dihydroergotamine and heparin in postoperative deep venous thrombosis following intra-abdominal operations

Postoperative pulmonary embolism continues to be a problem in patient care, especially in high-risk patients. This study was designed to evaluate a combined pharmacologic approach to the prophylaxis of postoperative deep venous thrombosis (DVT) by mediating at least two and probably three of Virchow's predisposing factors. Patients 40 years of age and older undergoing operations greater than 45 minutes under general anesthesia were placed in one of five treatment groups and studied by a prospective randomized, double-blind protocol. Study drugs were the following: (1) 0.5 mg of dihydroergotamine plus 5000 IU of sodium heparin (DHE 5000), (2) 0.5 mg DHE plus 2500 IU heparin (DHE 2500), (3) 5000 IU of HEP (HEP 5000), (4) 0.5 mg of DHE (DHE 0.5), and (5) a placebo. Study medications were administered 2 hours preoperatively and continuously thereafter every 12 hours postoperatively subcutaneously in the anterior abdominal wall for 5 to 7 days or until a positive radiofibrinogen uptake test (RFUT). The RFUT was performed according to standardized technique and was used to establish the presence or absence of DVT. This report is an analysis of the major subgroup of patients undergoing intra-abdominal operations. Results showed a highly statistically significant prophylactic benefit from DHE 5000 compared with the placebo (p < 0.003) and all other treatment groups (p < 0.05). There was no significant benefit from DHE 2500, HEP 5000 (p > 0.13), and DHE 0.5 (p > 0.3). All patients who entered the study had two or more risk factors for postoperative DVT, and high-risk patients were distributed equally throughout all treatment groups. DHE 5000 maintained its prophylactic benefit in high-risk patients. Evaluation of operative blood loss, postoperative blood loss, hematomas (wound or injection site), hematuria, postoperative hemoglobin difference, and adverse reactions revealed no significant difference between the study medications and the placebo. It is proposed that DHE 5000 has a synergistic prophylactic effect by mediating all three limbs of Virchow's triad: hypercoagulability (heparin), stasis (DHE), and vein wall injury secondary to venodilatation (DHE). DHE 5000 is recommended for patients at high risk of developing postoperative DVT and pulmonary embolism; however, it should be avoided in patients with acute myocardial infarction, sepsis, and sustained hypotension. (J VASC SURG 1984;1:608-16.)     

Thromboembolic prophylaxis in head trauma and multiple-trauma patients

The association between trauma and venous thromboembolism (VTE) is well recognized. VTE consists mainly of deep venous thrombosis (DVT) and pulmonary embolism, a complication that leads to mortality in nearly 50% of cases. Without thromboprophylaxis, the risk of DVT exceeds 50%, but even with routine use of prophylaxis,one third of patients may develop DVT. Despite these findings, appropriate DVT prophylaxis is often not prescribed in trauma patients, mainly because of fear that VTE prophylaxis increases bleeding in injured tissues. Pharmacological VTE prophylaxis is based on the use of low-molecular weight heparins (LMWH). Once-daily or twice-daily LMWH protocols started within 36 h of trauma and continued throughout the hospital stay, or once-daily LMWH followed by a twice-daily protocol are possible options. Mechanical VTE prophylaxis by graduated compression stockings or intermittent pneumatic compression provides suboptimal protection, and its use is recommended only in combination with LMWH prophylaxis unless active bleeding is not controlled. The routine use of VTE prophylaxis in trauma patients is a standard of care. The use of LMWH, started once primary hemostasis has been accomplished, is safe, efficacious and cost-effective in the majority of trauma patients, including TBI patients.     

Adjusted subcutaneous heparin versus heparin plus dihydroergotamine in prevention of deep vein thrombosis after total hip arthroplasty

In a prospective randomized study, two different antithrombotic regimens were compared with regard to their effects on the incidence of deep vein thrombosis (DVT) in 102 patients undergoing elective total hip arthroplasty. Fifty patients (group 1) received heparin subcutaneously three times daily in doses adjusted as a function of activated partial thromboplastin time (APTT), and 52 patients (group 2) received a fixed dose of 5,000 IU heparin plus 0.5 mg dihydroergotamine twice daily. Both treatments were started 2 days before operation and continued for 7-9 days after operation, when venography of the operated leg was performed in all patients. The overall incidence of DVT was 22% in group 1 and 19.6% in group 2. Eight patients (16%) in group 1 and four (7.6%) in group 2 developed proximal DVT. These differences were not statistically significant. Hemorrhagic complications occurred more frequently in group 1. Heparin plus dihydroergotamine is a simple and effective method of preventing DVT in patients undergoing total hip arthroplasty. Daily APTT-adjusted subcutaneous heparin remains the best method of prevention of DVT in patients with contraindications to the use of dihydroergotamine and those with two or more DVT risk factors.     

On thrombo-embolism after total hip replacement in epidural analgesia: a controlled study of dextran 70 and low-dose heparin combined with dihydroergotamine

A prospective study of thrombo-embolism after total hip replacement in epidural analgesia was carried out in 116 patients, randomly allocated to dextran 70 or low-dose heparin combined with dihydroergotamine (HDHE). Amounts of blood loss and transfused bank blood did not differ significantly between dextran 70 and HDHE prophylaxis. There was a lower incidence of femoral deep vein thromboses in patients given dextran prophylaxis as compared with those on HDHE (P less than 0.05). However, the total frequency of DVT and the frequency of pulmonary embolism did not differ between the two groups. There was no case of fatal pulmonary embolism. The side effects were major bleeding complications in 7 per cent of the HDHE group as compared to none in the dextran group. No anaphylactic reaction was noted from dextran 70 using hapten-dextran prophylaxis.     

Preoperative hemodilution for the prevention of postoperative deep venous thrombosis and early infectious complications in colorectal resections

The effectiveness of heparin DHE and preoperative haemodilution (M.N.H.) for prophylaxis against deep venous thrombosis (D.V.T.) and against early septic complications was investigated in a prospective controlled study on two comparable groups of patients who had undergone colorectal resections for malignant tumours. The results clearly suggested that there was no significant difference between heparin DHE and preoperative haemodilution for prophylactic effectiveness on D.V.T. yet, the percentage of postoperative septic early complications, that is insufficiency of anastomosis and abdominal wall infections, was much lower (p less than 0.001) in patients with moderate normovolaemic haemodilution (haematocrit = 30 per cent). While the number of cases reviewed was as low as 62, the point can be made that less postoperative septic complications occurred to patients with low haematocrit (30 per cent).     

The incidence of thromboembolism in the surgical intensive care unit

The clinical diagnosis of deep venous thrombosis (DVT) is unreliable. Studies have been performed examining the utility of frequent duplex scans. However, these studies included patients outside of the intensive care unit. The incidence of venous thromboembolism and the effect of a less intense surveillance protocol was prospectively examined at a level-1 urban trauma center for a 6 month period. During the study period there were 726 admission to the surgical intensive care unit. Sequential compression devices (SCDs) were used for DVT prophylaxis in 93 per cent of the admissions. A total of 114 duplex scans were ordered: 42 per cent for surveillance and the rest for evaluation of a clinical indication. Twelve DVTs were discovered (11% overall DVT rate). No patient on subcutaneous heparin or low-molecular-weight heparin developed a DVT or pulmonary embolism (PE). Four patients suffered a PE; however, none were found to have a lower extremity DVT on duplex ultrasound and all received SCD prophylaxis. Overall, proper use of DVT prophylaxis for intensive care unit days 1-14 was 77 per cent. The incidence of venous thromboembolism in a group of patients at overall high risk was low. A program of DVT surveillance with duplex ultrasound was not cost-effective.     

Randomized clinical trial of intermittent pneumatic compression and low molecular weight heparin in trauma

BACKGROUND: After trauma, up to 60 per cent of immobilized patients have been reported to develop a silent deep vein thrombosis (DVT). No large, prospective randomized trials have tested the efficacy of intermittent pneumatic compression (IPC) devices in these patients. METHODS: A prospective randomized trial was performed of 442 patients who received thromboprophylaxis using either an IPC device or low molecular weight heparin (LMWH). Duplex imaging was performed on both legs on admission, and was repeated weekly thereafter until discharge, at 30 days or when there was a thrombotic event, whichever occurred first. RESULTS: There were no significant differences in time spent in intensive care, or the proportion of patients with pelvic fractures, spinal cord or head injuries between the two groups. Six patients (2.7 per cent) developed a DVT in the IPC group and one (0.5 per cent) in the LMWH group (P = 0.122). Pulmonary embolism occurred in one patient in each group. There were 13 minor bleeding episodes (four in the IPC group and nine in the LMWH group) and eight major bleeding episodes (four in each group), none of which required operative intervention. CONCLUSION: The low rate of thromboembolic complications and the cost savings suggest that IPC might be used safely and effectively for thromboprophylaxis in trauma patients.     

Low molecular weight heparin compared with unfractionated heparin in prevention of postoperative thrombosis

Three consecutive randomized open studies have been carried out to determine the optimal dosage of low molecular weight heparin (LMWH) in the prevention of postoperative thrombosis in general surgery (892 patients). All patients undergoing abdominal, gynaecological, thoracic or urological surgery were over 40 years old and presented at least one of the following risk factors for thrombosis: previous thromboembolism, obesity, varicose veins, malignancy (30 per cent), pre-operative hospitalization over 5 days, oestrogen therapy, chronic cardiac disease or bronchitis. Isotopic venous thrombosis and bleeding complications were assessed after subcutaneous administration of a LMWH fragment (LMWH, Enoxaparine) or unfractionated heparin (UH). The three studies compared 3 X 5000 units UH daily with 1 X 60 mg, 1 X 40 mg, 1 X 20 mg LMWH daily. Thromboembolic events rates were not significantly different from group to group (UH: 3.8 per cent, 2.7 per cent, 7.6 per cent respectively compared with LMWH: 2.9 per cent, 2.8 per cent, 3.8 per cent). Bleeding episodes including wound haematoma formation, perioperative blood losses and systemic haemorrhage were not significantly different in patients receiving LMWH or UH. Significant decreases in haematocrit and haemoglobin were only observed in patients receiving 60 mg Enoxaparine (as compared to UH). An analysis using the 'intention to treat' approach gave results consistent with those of an analysis of good compliers. An overview of isotopic thromboses in the three studies gave no evidence of differences amongst the effects of the three doses of LMWH (P = 0.20), and pooling the results of the three studies using the Mantel-Haenszel procedure gave no evidence of a global difference between Enoxaparine and UH (P = 0.54). These results suggest that an optimal dosage of 20 mg/day of Enoxaparine is safe and effective in the prevention of postoperative thrombosis in this population.     

A Systematic Review of Deep Venous Thrombosis Prophylaxis in Cancer Patients: Implications for Improving Quality

Introduction Deep venous thrombosis (DVT) prophylaxis is particularly important for surgical oncologists given the high rate of DVT in patients with malignancy. Additionally, DVT prophylaxis may soon be implemented by some payers as a “pay for performance” quality measure. This is a systematic review of randomized controlled trial (RCT) evidence for DVT prophylaxis in cancer patients undergoing surgery. We examine overall rates of DVT, the efficacy of high versus low-dose heparin prophylaxis, and the rate of bleeding complications. Methods The Medline database was searched for English language RCTs using key words DVT, venous thromboembolism, prophylaxis, and general surgery. Inclusion criteria were RCTs evaluating surgical oncology patients. Results Fifty-five RCTs studied DVT prophylaxis in surgery (nonorthopedic) patients. Twenty-six RCTs evaluated 7,639 cancer patients. The overall DVT rate was 12.7% for pharmacologic prophylaxis and 35.2% for controls. High-dose low-molecular weight heparin (LMWH) was more effective than low dose, lowering the DVT rate from 14.5% to 7.9% (P < 0.01). Heparin decreased the rate of proximal DVTs. Bleeding complications requiring discontinuation of prophylaxis occurred in 3% of the patients. There was no difference between LMWH and unfractionated heparin in efficacy, DVT location, or bleeding complications. Conclusion Using RCT data, this study demonstrates a greatly reduced DVT rate with pharmacologic prophylaxis in cancer patients, and higher doses appear more effective. Complication rates are low and should not prevent the use of prophylaxis in most patients. Finally, we found no difference between LMWH and unfractionated heparin in these RCTs. These results highlight the importance of routine pharmacologic prophylaxis in surgical patients with malignancy. Presented at 2006 Society of Surgical Oncology Annual Meeting, San Diego, CA.     

Randomized clinical trial of low molecular weight heparin with thigh-length or knee-length antiembolism stockings for patients undergoing surgery

BACKGROUND: This was a randomized clinical trial to determine the efficacy and safety of a 'blanket' protocol of low molecular weight heparin (LMWH) and the best length of antiembolism stocking, for every patient requiring surgery under general anaesthesia. METHODS: Of 426 patients interviewed, 376 agreed to be randomized to receive one of three types of stocking: thigh-length Medi thrombexin climax (Medi UK, Hereford, UK), knee-length thrombexin climax and thigh-length Kendall T.E.D. (Tyco Healthcare UK, Redruth, UK). All patients received LMWH thromboprophylaxis. Duplex ultrasonography was used to assess the incidence of postoperative deep vein thrombosis (DVT). RESULTS: No postoperative DVT occurred in 85 patients at low or moderate risk. Nineteen DVTs occurred, all in the 291 high-risk patients: two with the Medi thigh-length stockings, 11 with the Medi knee-length stockings (odds ratio 0.18 (95 per cent confidence interval 0.04 to 0.82); P = 0.026) and six with the Kendall T.E.D. thigh-length stockings. No patient developed a pulmonary embolism. Stocking groups were similar for age, sex, thromboembolic risk, type of operation and compliance. One significant bleeding complication occurred. CONCLUSION: A single protocol comprising LMWH and thigh-length stockings abolished DVT in low- and moderate-risk patients, and reduced the rate of DVT to 2 per cent in high-risk patients.