Intermittent pneumatic calf compression for prevention of deep venous thrombosis in general abdominal surgery. Low dose heparin versus low molecular weight heparin (Kabi 2165, Fragmin) in the prophylaxis of thromboembolic complications of abdominal oncological surgery. Ultra-low dose intravenous heparin in the prevention of postoperative deep-vein thrombosis. Intermittent sequential pneumatic compression of the legs and thromboembolism-deterrent stockings in the prevention of postoperative deep venous thrombosis. Prevention of venous thrombosis with small, subcutaneous doses of heparin. 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. Prophylaxis of deep venous thrombosis after acute abdominal operation. Prevention of postoperative deep vein thrombosis in cancer patients. A randomized trial with low molecular weight heparin (CY 216). Drug prevention of postoperative deep vein thrombosis. A compararative study of calcium heparinate and sodium pentosan polysulfate. Controlled clinical study of the efficacy of a new low molecular weight heparin administered subcutaneously to prevent post-operative deep venous thrombosis. Low molecular weight heparin and prevention of postoperative thrombosis in abdominal surgery. Is DVT prophylaxis overemphasized? A randomized prospective study. Concentrated or diluted heparin prophylaxis of postoperative deep venous thrombosis. Effect of low-dose heparin on incidence of postoperative pulmonary embolism detected by photoscanning. Randomized, controlled trial of low molecular weight heparin vs. no deep vein thrombosis prophylaxis for major colon and rectal surgery in Asian patients. [Subcutaneous small heparin doses for the prevention of thrombosis in general surgery and urology]. Low-dose heparin in postoperative patients: a prospective, coded study.
A prospective randomized trial is described in 119 patients undergoing major abdominal general surgical procedures. Half of the patients were treated prophylactically with intermittent pneumatic calf compression, begun after the induction of anesthesia and continued until the patient was walking; the other half acted as controls. Deep venous thrombosis was detected by iodine-125 fibrinogen scanning and confirmed by venography, and did not differ significantly in the control and treated groups. One fatal pulmonary embolism occurred in each group. The presence of malignancy of the gastrointestinal tract did not influence the results. The findings suggest that pneumatic compression delayed the development of deep venous thrombosis postoperatively and that perhaps it should be continued until discharge from hospital. 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. Heparin (1 IU kg-1 h-1) given intravenously for 3-5 days during and after operation in a double-blind randomised study, significantly reduced the frequency of deep-vein thrombosis detected by 125I-fibrinogen uptake, and pulmonary embolism. 22% (11/50) control patients and 4% (2/45) patients receiving heparin had deep-vein thrombosis or pulmonary embolism. Heparin administration was not associated with any increase in preoperative or postoperative bleeding. One hundred fifty patients over the age of 30 who had undergone major abdominal operations were stratified according to the risk of deep venous thrombosis and randomized into three groups to receive different prophylactic regimens: group A, electrical calf stimulation; group B, low-dose subcutaneous heparin; group C, intermittent sequential compression and thromboembolism-deterrent (TED) stockings. All the patients were scanned with the 125I-fibrinogen test for the whole stay in hospital. The incidence of 125I-fibrinogen detected deep venous thrombi was 18% in group A, 9% in group B, and 4% in group C. The results indicate that the regimen of intermittent sequential compression and TED stockings is as effective as low-dose subcutaneous heparin. Electrical calf stimulation is less effective. The effect of low-dose heparin prophylaxis on venous thrombosis and bleeding after major elective surgery was studied in a prospective controlled study of 820 patients. The total incidence of venous thrombosis detected with leg-scanning using fibrinogen labeled with radioactive iodine (125I) was reduced from 16.0% in the control group to 4.2% in treated patients. More important, the incidence of popliteal or femoral vein thrombosis was reduced from 2.9% to 1.0%. Prophylaxis resulted in a slight increase in bleeding-minor wound hematoma, mean volume of blood transfused, and a post-operative hematocrit fall in treated patients. However, increased bleeding was clinically minor, and prophylaxis was well tolerated. 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. Two hundred and forty-five patients who underwent acute extensive abdominal operations were randomized into three regimens to achieve optimal prophylaxis of postoperative thromboembolic complications. All of the patients were screened by the 125I-fibrinogen uptake test for seven days and if the phlebographic findings were positive. Of 81 patients receiving low dose heparin, 12 had thromboembolism. Of 79 receiving a combination of low dose heparin and graded compression stockings, two had thromboembolism, and of 85 receiving a combination of dextran and graded compression stockings, 13 had this complication. This difference is significant in favor of the second treatment (p = 0.013). It is concluded that the combination of low dose heparin and graded compression stockings is an effective way to prevent thromboembolism after acute abdominal operations. Sixty-one consecutive patients were enrolled in a randomized, controlled trial of thromboprophylaxis with a low molecular weight heparin (Seleparina, CY 216) in major abdominal oncological surgery. Thirty patients received 2 x 3,825 anti-Xa international units of CY 216 subcutaneously on the day of surgery followed by a single daily 3,825 anti-Xa international units injection for 7 days; thirty-one patients did not receive any form of prophylaxis. The occurrence of deep vein thrombosis (DVT) was detected by 125I-labelled fibrinogen leg scan. Postoperative DVT developed in 2 patients in the CY 216 group and in 11 patients in the control group (6.8% vs 35.4%, p < 0.01). Although there was a higher postoperative transfusional requirement in the group receiving CY216 (p < 0.05), the total number of patients transfused was similar in the two groups (14 vs 13). On day 1 after surgery, the two patients who later developed DVT in the CY216 group had plasma anti-Xa activity significantly lower (p < 0.01) than the remaining patients. As a good relationship was found between plasma anti-Xa activity and body weight, adoption of a personalized dosage schedule might improve efficacy of CY 216 prophylaxis. Deep vein thrombosis and its sequel, pulmonary embolus, are possibly the greatest threats to recovery after surgical operation. In a randomized, controlled clinical trial in which the 125I-fibrinogen uptake test, Doppler ultrasound, and phlebography were used for diagnosis, it was found that low doses of calcium heparinate administered subcutaneously and sodium pentosan polysulfate intramuscularly were effective in preventing deep vein thrombosis (DVT), postoperatively. The incidence of DVT was as follows: 9% in the group treated with heparinate; 15% in the group treated with sodium pentosan polysulfate; nad 51% in the untreated control group. A double-blind, placebo-controlled study was carried out in 100 patients undergoing major surgery to investigate the efficacy of a new low molecular weight heparin (LMWH) preparation in the prevention of deep venous thrombosis. Patients were allocated at random to receive either placebo or LMWH (7500 AXaU) each day by subcutaneous injection (abdominal fold method), starting 2 hours before the operation and continuing for the following 7 days. Clinical and laboratory tests revealed deep venous thrombosis in 3 (6%) patients in the placebo group whereas no thrombotic episodes were observed in any of the patients treated with LMWH. Blood loss during the peri-operative and post-operative period and the number of blood units transfused were not significantly different in the two groups. Moreover, no side-effects were revealed in the LMWH group that could be attributed to the drug. In a prospective, double-blind, randomized multicenter trial the efficacy and safety of low molecular weight heparin and unfractionated heparin were compared for the prevention of postoperative deep vein thrombosis in patients undergoing abdominal surgery. Six hundred and seventy-three patients were randomly allocated to the two prophylaxis groups; 20 of these, however, did not undergo surgery and did not receive any prophylaxis. Of the remaining 653 patients 323 received one subcutaneous injection of 3,000 anti-Xa units of low molecular weight heparin and 330 received subcutaneously 5,000 U heparin three times a day. Treatment was initiated 2 h preoperatively and continued for 7 to 10 days. The occurrence of DVT was determined by the 125I-labelled fibrinogen uptake test and phlebography. Venous thrombosis was diagnosed in 24 of 323 patients (7.4%) treated with low molecular weight heparin and in 26 of 330 patients (7.9%) treated with low-dose heparin. DVT of proximal veins was detected in four patients of the low molecular weight heparin group and in three patients of the low-dose heparin group. During the observation period three pulmonary emboli - one fatal and two non-fatal - occurred in patients receiving prophylaxis with low-dose heparin. No pulmonary embolism was found in patients treated with low molecular weight heparin. Both prophylactic schemes were well tolerated. Intra- and postoperative blood loss, incidence of wound hematoma, frequency and volume of intra- and postoperative blood transfusion were similar in both groups with a slight advantage for the low molecular weight heparin group.(ABSTRACT TRUNCATED AT 250 WORDS) This study was designed to prospectively evaluate a previously published prognostic index for predicting deep venous thrombosis (DVT) in general surgical patients with conventional prophylaxis. Patients undergoing procedures of at least 1 hr duration (abdominal, thoracic, head and neck, inguinal) requiring general or spinal anesthetic were prospectively randomized into the following groups: Group 1, sequential pneumatic compression devices during surgery and 2 days postoperatively; Group 2, subcutaneous heparin (5000 U q 12 hr) starting 1 hr before surgery and for 7 days postop; Group 3, control group. All patients underwent duplex evaluation of bilateral lower extremity deep venous systems preoperatively and on postoperative Days 1, 3, and 30. In addition, a previously developed predictive DVT incidence indicator, the prognostic index (PI), was calculated for each patient. A total of 137 patients were entered into the study with 29 removed for patient/staff reasons. There were no differences in PI among the three groups at the 0.05 level (ANOVA). The distribution of risk factors for DVT including increased age, body size, hemoglobin (Hb), and colorectal procedures were distributed evenly among the groups. Additional factors such as diabetes, COPD, PVD, immobilization, and cancer were also evenly distributed among the groups. The PI predicted a 20% incidence of DVT. For Groups 1 (n = 25), 2 (n = 38), and 3 (n = 45) no DVTs were detected over the 30 days of study. During the study period, 8 DVTs were detected by duplex evaluation in general surgical patients not in the study (1.5%). In conclusion, in a prospective randomized study using sequential pneumatic compression devices, subcutaneous heparin or no prophylaxis in matched general surgical patients at moderate to high risk for thromboembolism, no DVTs occurred for up to 30 days. Furthermore, neither a PI nor other factors associated with DVT accurately predicted the incidence of DVT in this patient population. A concentrated and a diluted heparin solution (Vitrum AB) have been evaluated in a controlled blind study, using a standard dosage of 5 000 IU, given every 12 hours subcutaneously. 167 patients undergoing abdominal surgery were randomized into three groups: 63 received diluted heparin 5 000 IU/ml, 43 received concentrated heparin 25 000 IU/ml and 61 patients served as controls. 80 per cent of the patients suffered from malignant disease. Deep venous thrombosis (DVT), diagnosed with the 125I-fibrinogen method, was found in 16% of the patients receiving diluted heparin, in 23% of those receiving concentrated heparin and in 33% of the controls. To evaluate the amount injected, an in vitro experiment was performed in which the intended dose was 5 000 IU. The measured amount of the concentrated heparin solution was significantly less than 5 000 IU. It is concluded that the frequency of DVT after gastrointestinal operations can be reduced significantly (in the present study from 33 to 16%) by administering diluted calcium heparin every 12 hours for 6--8 days. The concentrated heparin solution did not significantly reduce postoperative DVT, possibly on account of variations in the dosage. Diluted heparin prophylaxis can be achieved without serious side effects. nan Routine deep venous thrombosis prophylaxis is controversial in Asian patients, because deep venous thrombosis incidence was considered negligible. Because of recent reports of significantly higher incidences, a randomized, controlled trial was conducted to assess the effectiveness and complications of enoxaparin prophylaxis (low molecular weight heparins) in major colorectal surgery.
                Three hundred twenty consecutive patients were randomly assigned to control or low molecular weight heparins groups. Patients in the low molecular weight heparins group were given perioperative enoxaparin starting 12 hours before surgery. The surgeon (blinded) assessed for difficulties related to possible enoxaparin administration. Independent blinded observers performed daily clinical assessments and Doppler studies (at the 3rd and 5th postoperative day). Deep venous thrombosis was confirmed by duplex ultrasound, and pulmonary embolism was confirmed by lung scans or postmortem examinations.
                Deep venous thrombosis developed in 5 of 169 (3 percent) controls and 0 of 134 low molecular weight heparins patients (P = 0.045). Three of the deep venous thrombosis patients had pulmonary embolism, which was fatal in one patient. The surgeons were unable to perceive any increased surgical difficulties in the low molecular weight heparins group. The bleeding-related complications were significantly higher in the low molecular weight heparins patients (controls, n = 3 (1.8 percent); low molecular weight heparins, n = 9 (6.7 percent)). However, apart from one subdural hematoma and two abdominal hemorrhages needing re-exploration, which also occurred in one of the controls, these complications were minor bruises at the wounds, drains, or injection sites.
                Deep venous thrombosis prophylaxis is needed in Asian patients undergoing major colorectal surgery. 1. The effectiveness of 3 X 5000 IU s. c. heparin daily (starting preoperatively) for the prevention of postoperative deep vein thrombosis was evaluated in a prospective, controlled, randomized study including general surgical and urological patients. 125I-fibrinogen test was performed daily in all patients. 2. 178 patients fulfilled the conditions of the protocol. 35.8% of the 95 patients in the control group developed deep vein thrombosis, but only 13.3% of 83 subjects in the heparin group did so. The difference is statistically highly significant (p less than 0.001). 3. The vast majority of all thrombi in both groups appeared before the 3rd postoperative day. 4. With 1 exception, all deep vein thrombi in the heparin group started in the mid-calf region. In the control group 5 deep thrombi originated in the popliteal vein. 5. Heparin displays a better effect in males (n = 34; p less than 0.01) than in females (n = 49; p less than 0.025). 6. In patients undergoing surgery for malignant disease heparin does not reduce the incidence of deep vein thrombosis. 7. Heparin is far more effective in patients under 60 years of age than in those over 60 (p less than 0.005). 8. Heparin is more effective in obese patients than in those of normal body build. 9. Heparin prophylaxis also reduces the incidence of deep vein thrombosis in patients who exhibit predisposing factors. In patients of the control group with preexisting disease of the venous system, there were significantly more deep vein thrombi (p less than 0.01) than in those without predisposing factors. 10. In the heparin group 29% of all thrombin time determinations show a definite prolongation of more than 26 sec (normal value 15 sec). 11. In 14 patients (=16.9%) of the heparin group, 21 side effects or complications were seen. Bleeding complications were the main problem, comprising 5 wound hematomas and hematomas at the injection site, 4 postoperative bleeding episodes and 2 reoperations. There were no complications in the control group. 12. According to the results of 10 well controlled studies, there is no doubt that in general surgery small doses of subcutaneous heparin, commencing preoperatively, do reduce the incidence of postoperative deep vein thrombosis to a significant degree. However, whether this form of prophylaxis is also effective in patients with fractures of the hip and in elective hip surgery cannot, on the evidence available, be decided. In the fields of gynecological surgery and urology as well, more data are needed before this form of heparin prophylaxis can be recommended. One hundred five patients over age 40 undergoing various major operations were randomly divided into control and treated groups; all were treated by subcutaneous injection containing either 5,000 international units aqueous heparin sodium or a placebo one hour prior to operation and every 12 hours thereafter for eight days. Deep vein thrombosis (DVT) was detected by daily -125I-fibrinogen injection and leg scanning, and confirmed by ascending phlebography. Both groups were comparably distributed by age, sex, variety of operation, incidence of previous thromboembolism, and myocardial and cerebrovascular disease. Blood loss was not increased in the treated group. Incidence of DVT was 8.6 percent for the total group, 7.5 percent in the heparin-tested group (four of 53), and 9.6 percent in the control group (five of 52), including one control patient with a normal scan (who later had a pulmonary embolus.
The optimal prophylaxis in colorectal surgery is the combination of graduated compression stockings and low-dose unfractionated heparin. The unfractionated heparin can be replaced with low molecular weight heparin.