Comparison of enoxaparin and standard heparin in gynaecologic oncologic surgery: a randomised prospective double-blind clinical study. Low dose heparin versus low molecular weight heparin (Kabi 2165, Fragmin) in the prophylaxis of thromboembolic complications of abdominal oncological surgery. Subcutaneous heparin versus low-molecular-weight heparin as thromboprophylaxis in patients undergoing colorectal surgery: results of the canadian colorectal DVT prophylaxis trial: a randomized, double-blind trial. A low molecular weight heparin (KABI 2165) for prophylaxis of postoperative deep venous thrombosis. Haemostatic molecular markers in patients undergoing radical retropubic prostatectomy for prostate cancer and submitted to prophylaxis with unfractioned or low molecular weight heparin. Orgaran (Org 10172) or heparin for preventing venous thrombosis after elective surgery for malignant disease? A double-blind, randomised, multicentre comparison. ANZ-Organon Investigators' Group. Thromboprophylactic effect of low molecular weight heparin started in the evening before elective general abdominal surgery: a comparison with low-dose heparin. Blood coagulation and thrombosis in patients with ovarian malignancy. Evaluation of perioperative fatal pulmonary embolism and death in cancer surgical patients: the MC-4 cancer substudy. Effect of low molecular weight heparin (Certoparin) versus unfractionated heparin on cancer survival following breast and pelvic cancer surgery: A prospective randomized double-blind trial.
This study aimed to compare the haemorrhagic complications and efficacy of enoxaparin, a low molecular weight heparin (LMWH), and conventional standard heparin (SH) in gynaecological oncologic surgery. MATERIALS METHODS: A double blind, randomised trial was performed on 102 consecutive women undergoing gynaecologic cancer surgery with pelvic and paraaortic lymphadenectomy. The women were separated into those who were given 2,500 IU enoxaparin once daily and SH in a dose of 5,000 IU three times daily. The groups were analysed for intraoperative blood loss, drainage, transfusion requirements, perioperative haemoglobin decrease, wound haematoma, and clinical deep venous thrombosis.
                The two groups were well matched for age, weight, and other factors, which could predispose to the development of deep venous thrombosis (DVT) and haemorrhage. No patient developed clinical significant DVT, wound haematoma or intra-abdominal bleeding. There was no significant difference in bleeding complications between the two regimens. The antiFXa level in the plasma was correlated strongly with patient weight.
                A dose of 2,500 IU enoxaparin/day does not cause more bleeding complications than SH 5,000 IU three times daily when used to prevent thrombosis. However, the dose of enoxaparin must be adjusted to the patient's weight. Eighty patients undergoing pelvic or abdominal surgery for cancer were randomized in two groups for prevention of postoperative thromboembolism: 40 patients received a 15,000 IU day-1 Calciparine prophylaxis and 40 patients a 5000 anti-Xa U/d Fragmin prophylaxis for 10 days. In the Calciparine group, two patients (5%) developed postoperative pulmonary embolism but none developed it in the Fragmin group. Two patients in the Fragmin group (5%) developed isotopic DVT, which was not confirmed by phlebography. There was no deep vein thrombosis of the lower limbs in the two groups. Important postoperative bleeding (one patient in the Calciparine group and two patients in the Fragmin group) was similar in both groups. Moderate and minor bleeding were significantly lower in the Fragmin group. Haemoglobin and haematocrit changes, total blood loss and transfusion requirements were not different in both groups. It is concluded that, over a 10-day period, one daily 5000 U Fragmin prophylaxis was as effective and safe as three daily 5000 IU Calciparine injections. To compare the effectiveness and safety of low-dose unfractionated heparin and a low-molecular-weight heparin as prophylaxis against venous thromboembolism after colorectal surgery.
                In a multicenter, double-blind trial, patients undergoing resection of part or all of the colon or rectum were randomized to receive, by subcutaneous injection, either calcium heparin 5,000 units every 8 hours or enoxaparin 40 mg once daily (plus two additional saline injections). Deep vein thrombosis was assessed by routine bilateral contrast venography performed between postoperative day 5 and 9, or earlier if clinically suspected.
                Nine hundred thirty-six randomized patients completed the protocol and had an adequate outcome assessment. The venous thromboembolism rates were the same in both groups. There were no deaths from pulmonary embolism or bleeding complications. Although the proportion of all bleeding events in the enoxaparin group was significantly greater than in the low-dose heparin group, the rates of major bleeding and reoperation for bleeding were not significantly different.
                Both heparin 5,000 units subcutaneously every 8 hours and enoxaparin 40 mg subcutaneously once daily provide highly effective and safe prophylaxis for patients undergoing colorectal surgery. However, given the current differences in cost, prophylaxis with low-dose heparin remains the preferred method at present. In a prospective double-blind trial, low molecular weight (LMW) heparin (KABI 2165) 5,000 U (anti-Xa) once daily was compared with conventional heparin 5,000 IU twice daily, both given subcutaneously, as regards prevention of postoperative deep venous thrombosis (DVT) in 52 patients undergoing major abdominal surgery. Radioactive fibrinogen uptake test (FUT) was used for DVT screening. DVT, diagnosed from positive FUT, developed in two patients from each group, but could be phlebographically confirmed in only one (LMW) case. No intergroup differences were found in peroperative blood loss or requirements for blood transfusion. Complications attributable to the prophylactic regimens were few. In the LMW-heparin group, the anti-Xa levels measured during operation showed considerable variation, the higher activities (greater than 0.30 U/ml) being nonsignificantly associated with increased blood loss. Studies with lower doses of LMW-heparin are recommended. Deep vein thrombosis and subsequently pulmonary embolism are the most common causes of increased post-operative morbidity and mortality in patients with pelvic or abdominal cancer. Aim of the study was to evaluate variations in coagulative parameters induced by two accepted primary prophylaxis patterns: standardized low doses of unfractioned heparin (UFH) or single doses of low molecular weight heparin (LMWH) in cancer patients submitted to radical retropubic prostatectomy.
                Fifty patients (45-75 yr) were randomly assigned two groups. Group 1 received UFH (5000 units s.c. x 3 daily); group 2 received calcium nadroparin (single daily dose of 0.3 ml s.c.). In both groups prophylaxis began preoperatively and was maintained throughout the entire hospital-stay. Blood cell, platelet count, coagulative system exploring tests, thrombotic molecular markers, and physiological inhibitors of coagulation were determined at baseline conditions and on the first and seventh day after surgery.
                Preoperative values of fibrinogen, F1+2 fragment, TAT and D-dimer resulted over normal range in both groups. A significant increase of these markers was observed also during the post-operative period. PT, aPTT, ATIII, PC, total and free PS showed the most substantial changes on the 1st post operative day, though their values ranged within normal levels on the three sampling times. The levels of haemostatic markers demonstrated a baseline hypercoagulability, probably related to cancer and thrombin activation caused by prostatectomy. Despite this thrombophylic state, neither of the two groups presented symptomatic bleeding or thromboembolic complications.
                These results prove that a single daily dose of nadroparin has been safe and efficient as a thrice-daily dose of UFH, with a better risk/benefit relationship. This double-blind, randomised, multicentre trial in 513 patients having elective surgery for intra-abdominal or intrathoracic malignancy compared the efficacy and safety of venous thrombosis (VT) prophylaxis using 750 anti-factor Xa units of Orgaran (a mixture of low molecular weight heparinoids) given subcutaneously (sc) twice-daily with that of twice-daily injections of 5,000 units standard heparin. The main study endpoints were the development of postoperative VT detected by 125I-fibrinogen leg scanning, and the onset of clinically significant venous thromboembolism or bleeding. "Intent to treat" analysis showed a statistically non-significant trend towards less VT during Orgaran prophylaxis (10.4%) than after heparin (14.9%) and there was no difference in bleeding complications between the two study groups. Results remained similar if only patients who completed the intended course of therapy ("compliant patients") were analysed. Other trials have shown that Orgaran prevents VT after hip surgery and stroke. We now show it is also safe and effective in patients having major surgery for cancer. A prospective randomized double-blind trial was performed comparing conventional low-dose heparin with a LMWH fragment (Kabi 2165, Fragmin) for thromboprophylaxis in elective general abdominal surgical patients. The first dose of the fragment was given in the evening before surgery, and thereafter every evening. There were 1002 analyzable patients, 826 having received correct prophylaxis. Sixty three percent of the patients were operated on for malignant diseases. The frequency of DVT was significantly reduced among patients with correct prophylaxis with the heparin fragment (9.2 to 5.0%, p = 0.02). In patients with malignancies the reduction was from 11.2 to 6.4% (p = 0.06). The frequency of bleeding was 6.7% among the heparin fragment patients and 2.7% among the patients given conventional heparin (p = 0.01). The corresponding frequencies for patients with malignancies were 3.2 and 2.8%, respectively (p = 0.28). All bleedings were minor and of no clinical significance. Local pain at the injection site was reported significantly less often among patients with the fragment. Twenty patients died, 13 with malignant disease, mortality being the same in the two groups. It is concluded that heparin fragment administered in the evening before surgery and then every evening is a practically acceptable alternative to prevent postoperative DVT in patients undergoing elective abdominal surgery, also when the histology shows malignancy. Thus, the advantages of using LMWH compared with conventional low-dose heparin are simplified administration routines, better thromboprophylactic effect, and less local pain at injection sites. A disadvantage is the slight increase in hemorrhagic side effects, all of minor clinical importance and not seen in patients undergoing surgery for malignancy. Ovarian cancer cells appear to be capable of both thrombin formation and induction of fibrin degradation which may be essential prerequisites for the development of deep vein thrombosis (DVT) as well as the spread of malignancy. To study further this coagulation-cancer interaction in 60 patients with untreated ovarian cancer of FIGO stage I-IV the incidence of DVT was recorded pre-operatively, post-operatively on day 1, 3, 5, 7, 10, before each of six cycles of Cisplatinum/ Epirubicin/Cyclophosphamide chemotherapy, during follow-up and in the post-operative period of second look surgery. In addition, blood coagulation tests results were determined prospectively. Two patients were excluded from these calculations due to previous DVT 5 to 6 weeks before the diagnosis of ovarian cancer but all patients were eligible for surgery and randomized to receive either daily low molecular weight heparin (LMWH) (n = 28) or unfractionated heparin (UFH) (n = 32) for perioperative thrombosis prophylaxis until the 7th post-operative day. According to the FIGO stage, patients were equally distributed in the 2 heparin treatment groups. The predictive value of pre-operative coagulation test results, clinical parameters, and type of heparin used were tested in univariate and multivariate analysis for development of post-operative DVT and overall patients survival. Impedance plethysmography for DVT screening was used. The presence of DVT was then confirmed by phlebography. Only D-dimer and fibrinogen levels were correlated significantly with the FIGO stage while antithrombin, protein C, and plasminogen activator inhibitor activity were not. The incidence of DVT was 6.7% (4/60) up to the 7th and 8.3% (5/60) between the 8th and 29th post-operative day. DVT occurred in 10.6% (5/47) during chemotherapy. Pre-operative coagulation test results, the type of heparin used, and clinical parameters were not significant risk factors for post-operative DVT development in univariate analysis. The D-dimer and fibrinogen levels were significant risk factors for reduced overall survival in univariate analysis but only the FIGO stage was an independent predictor (in multivariate analysis). After a median follow up of 26.5 months (min. 8 months, max. 41 months), 21.4% of LMWH treated and 37.5% of UFH-treated patients died of cancer (p = 0.26). Pre-operative test results were neither predictive for DVT nor the outcome of cancer but patients showed an improved though not statistically significant overall survival after LMWH treatment. Cancer patients undergoing surgery are at a high risk of venous thromboembolism, but few studies have described the rate of autopsy-confirmed fatal pulmonary embolism after heparin thromboprophylaxis. In a post hoc analysis of a randomized study (MC-4), which compared the efficacy and safety of certoparin (3000 anti-Xa IU, subcutaneously, once-daily) with unfractionated heparin (5000 IU, subcutaneously, three-times daily) in 23078 patients undergoing surgery lasting more than 30 min, the incidence of autopsy-confirmed fatal pulmonary embolism, death and bleeding in the cancer patients (n=6124) was compared with non-cancer patients (n=16954). Fatal pulmonary embolism was significantly more frequent in cancer patients (0.33% [20/6124]) than in non-cancer patients (0.09% [15/16954], relative risk (RR), 3.7 [95% confidence intervals (CI), 1.80, 7.77], p=0.0001) at 14 days post-prophylaxis. Perioperative mortality was also significantly higher in cancer patients than in noncancer patients (3.14% [192/6124] vs. 0.71% [120/16954], RR, 4.54 [95% CI, 3.59, 5.76], p=0.0001), as were blood loss (p<0.0001), and transfusion requirements (p<0.0001). Prevention of venous thromboembolism in cancer surgical patients remains a clinical challenge. Recent studies suggest that low molecular weight heparin (LMW heparin) therapy in malignancy may improve cancer survival following surgical resection. We studied prospectively whether cancer mortality during follow-up in women with previously untreated breast, and pelvic cancer is reduced in those who randomly received LMW heparin (Certoparin) compared to patients given unfractionated heparin (UF heparin) for thrombosis prophylaxis during primary surgery. In a prospective, randomized, double-blind clinical trial, 160 patients received Certoparin and 164 UF heparin until post-operatively day 7. Survival estimations are based on the outcome data from a subset of 140 LMW heparin - and 147 UF heparin recipients. Long-term survival in the Certoparin group compared to the UF heparin group was significantly improved after 650 days (P=0. 0066) but not thereafter when analysis was performed on all cancer cell types combined. In the probability estimates survival benefit within this time was restricted to patients with pelvic cancer but was not observed in breast cancer. However, in breast cancer patients who received LMW heparin the impact of classical tumor prognostic markers was statistically significant after 1,050 days but not after 650 days. Thus, breast cancer patients with unfavorable prognosis seem to benefit in terms of survival advantage from LMW heparin within the 650 days after surgery. These results suggest that improvement in cancer survival can be achieved after even a short course of treatment with LMWH (compared to UFH) given for DVT prophylaxis in the post-operative period. An effect of UFH on disease outcome is not excluded. Further definitive trials of LMWH vs. placebo for cancer outcome (rather then DVT) using doses and schedules that may be more optimal are indicated.
We found no difference between perioperative thromboprophylaxis with LMWH verus UFH in their effects on mortality and embolic outcomes in patients with cancer. Further trials are needed to more carefully evaluate the benefits and harms of different heparin thromboprophylaxis strategies in this population.