Low Molecular Weight Heparin and Prevention of Postoperative Thrombosis in Abdominal Surgery

Abstract

SummaryIn 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. The results of this trial show that the investigated low molecular weight heparin is at least as effective and safe as low-dose heparin in preventing deep vein thrombosis in patients undergoing elective abdominal surgery.

Low molecular weight heparin for the prevention of venous thromboembolism after abdominal surgery

“…The incidence of PE, bleeding complications, the number and frequency of transfusions, and intraoperative and postoperative blood loss were similar in the two prophylactic groups 12 . Similarly, using a lower dose of fraxiparin of 3000 anti-Xa units once daily in a trial of 653 patients, Koppenhagen et al 13 reported no difference in DVT incidence between LMWH and UFH groups (7·4 versus 7·9 per cent respectively). The lower dose of LMWH was associated with no alteration in bleeding complications.…”

“…Additional data on the efficacy and safety of LMWH was produced by two trials in which the LMWH fraxiparin was compared with UFH 5000 units three times a day 12,13 . In the European Fraxiparin Study Group study, both objectively confirmed DVT (2·8 versus 4·5 per cent; P < 0·050) and proximal DVT (0·4 versus 1·4 per cent; P < 0·050) occurred less frequently in patients receiving LMWH 7500 anti-Xa units once daily than in the UFH group 12 .…”

Unexpected complication of massive intraoperative pulmonary embolism following elective sigmoidectomy in the supine position

“…It is reported that the use of 3000 IU anti-Xa, 2 h prior to abdominal surgery, eliminates the risk of PTE [7,8]. Even though we adhered to all recommendations for VTE prevention (4000 IU anti-Xa enoxaparin administration and GCS use), and although the patient was initially stratifi ed as being at high risk for PTE, these measures were inadequate to prevent such a serious complication from occurring.…”

Toward the individual approach to the evaluation of risks and prevention of postoperative venous thromboembolism

“…У пациентов отделения интенсив ной терапии на фоне соблюдения превентивных протоколов вероятность развития тромбоза коле блется от 5,5 до 33% (в среднем 12,0%) [48][49][50][51][52][53][54][55][56][57]. У пациентов общехирургического профиля, относя щихся к категории высокого риска, после вмеша тельств на органах брюшной полости и малого таза частота ВТ на фоне изолированного применения одной профилактической методики (эластичной или пневматической компрессии, профилактиче ских доз антикоагулянтов) составляет около 11-13%, а при сочетании нескольких методов уменьша ется до 2% [17,26,27,34,[58][59][60][61][62][63][64][65][66][67][68][69][70][71][72][73][74][75]. При анализе эф фективности отдельных превентивных средств в группе высокого риска можно увидеть следующие цифры: частота развития ВТ на фоне применения стандартных доз гепаринов колеблется от 1,9 до 33%, составляя в среднем 13,4% [18-21, 23, 25, 28, 32-36, 38, 40, 42, 44, 45, 47-57, 59, 60, 62, 64-67, 69-71, 73-82]; на фоне изолированного использо вания эластичной компрессии -от 6 до 26% (сред няя 13,2%) [22,24,27,43,44,46,61,…”