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Prolonged thromboprophylaxis with Low Molecular Weight heparin for abdominal or pelvic surgery

  • Review
  • Intervention




Major abdominal and pelvic surgery carries a high risk of venous thromboembolism (VTE). The efficacy of thromboprophylaxis with low-molecular weight heparin (LMWH) administered during the in-hospital period is well documented, but the optimal duration of thromboprophylaxis after surgery remains controversial. Some studies suggest that patients undergoing major abdominal surgery benefit from prolongation of the thromboprophylaxis to 1 month after surgery. No systematic review on prolonged thromboprophylaxis after major abdominal or pelvic surgery has been published.


To evaluate the efficacy and safety of prolonged thromboprophylaxis with LMWH for at least 1 month after abdominal or pelvic surgery with thromboprophylaxis administered during the in-hospital period only in preventing late VTE.

Search methods

Electronic searches were performed January 2008 in the Medline, Embase, Lilacs, and the Cochrane Central Register of Controlled Trials. Abstract books from major congresses addressing thromboembolism were hand searched, as were reference lists from studies of relevance.

Selection criteria

We assessed both randomised and non-randomised controlled clinical trials comparing prolonged thromboprophylaxis with any anti-thrombotic agent with placebo and/or thromboprophylaxis during the admission period only. The patient population in the trials were patients undergoing abdominal or pelvic surgery. The outcome measures included VTE (deep venous thrombosis (DVT) or pulmonary embolism (PE)) as assessed by objective means (ascending bilateral venography, ultrasonography, pulmonary ventilation/perfusion scintigraphy, spiral CT scan or autopsy). Studies exclusively reporting on clinical diagnosis of VTE, without objective confirmation were excluded.

Data collection and analysis

The identification of studies and data extraction were performed by the authors. Outcomes were VTE (DVT or PE) assessed by objective means. Safety outcome were defined as bleeding complications and mortality within 3 months after surgery.

Main results

The search exclusively detected trials evaluating prolonged thromboprophylaxis with LMWH as compared to control or placebo. 133 studies were found in the searches, of which only 4 were found eligible for inclusion, and 129 were excluded. The incidence of overall VTE after major abdominal or pelvic surgery was 14.3% (95% confidence interval 11.2% - 17.8%) in the control group as compared to 6.1% (95% CI 4.0% - 8.7%) in the patients receiving out-of-hospital LMWH. This difference was statistically significant, Peto Odds Ratio 0.41 (95% CI 0.26 -0.63), P < 0.0005. Prolonged thromboprophylaxis with LMWH was also associated with a statistically significant reduction of even the incidence of symptomatic VTE from 1.7% (95% CI 0.8% - 3.4%) in the control group to 0.2 % (95% CI 0.0% - 1.2%) in patients receiving prolonged thromboprophylaxis, Peto Odds ratio 0.22 (95% CI 0.06 -0.80), P = 0.02. The respective incidence of bleeding in the control and LMWH group were 3.7% (95% CI 2.4% -5.5%) and 4.1% (95% CI 2.7% - 6.0%), Peto Odds ratio 1.11 (95% CI 0.62 - 1.97), P = 0.73. There was no significant heterogeneity detected as regards to outcome parameters reported in the included trials.

Authors' conclusions

Prolonged thromboprophylaxis with LMWH significantly reduces the risk of VTE compared to thromboprophylaxis during hospital admittance only, without increasing bleeding complications after major abdominal or pelvic surgery.








電子搜查2008年1月完成在了MEDLINE,EMBASE, Lilacs,和Cochrane Central Register 的對照試驗.從主要討論血栓代表大會,摘要本書.從研究的相關性,手工搜查參考文獻。


我們的評估隨機和非隨機對照臨床試驗比較長期的血栓預防與任何抗血栓劑與安慰劑和/或thromboprophylaxis,只有在入院期間。接受試驗的患者是腹部或骨盆手術的患者。結果措施包括:深部靜脈栓塞(DVT)或肺栓塞(PE)為客觀的評估方法(ascending bilateral venography, ultrasonography, pulmonary ventilation/perfusion scintigraphy, spiral CT scan or autopsy)。深部靜脈栓塞的臨床診斷的專門研究報告,沒有客觀的證據被排除在外.




完全檢測搜索試驗評估長期的血栓預防及低分子量肝素或安慰劑的比較,控制.在搜查中133個研究發現,其中只有4個有資格列入,129個被排除在外.主要腹部或骨盆手術後的整體深部靜脈栓塞控制組發生率 14.3% (95% 可信區間11.2% −17.8%)比較患者接受院外低分子量肝素發生率6.1% (95% CI 4.0% −8.7%).這種差異有統計學意義, Peto比值比為0.41(95%CI為0.26 −0.63),P<0.0005.長期的血栓預防與低分子量肝素也是有關的,當患者接受長期的血栓預防,顯著的減少了症狀性深部靜脈栓塞的發生率在控制組從1.7% (95% CI 0.8% −3.4%)到0.2 %.出血的個別發生率在控制組和低分子量肝素組是3.7%(95% CI 2.4% −5.5%)和4.1% (95% CI 2.7% −6.0%), Peto Odds ratio 1.11 (95% CI 0.62 −1.97), P = 0.73.在試驗中,無顯著異質性檢測被視為結果參數報告.





此翻譯計畫由臺灣國家衛生研究院(National Health Research Institutes, Taiwan)統籌。



Plain language summary

Prolonged administration of low molecular weight heparin lowers the number of blood clots in the lower limbs after operation in the abdomen or pelvis

Patients subjected to major surgery of the abdomen are at considerable risk of developing blood clots in the veins of the lower limbs. These clots may detach and develop clots in the lungs and cause sudden death. Clots in the limbs may impaire the venous function leading to a life-long tendency to swollen legs and leg ulceration. In order to avoid these complications patients are often offered protective medicine during the first week after surgery, but patients are probably at risk of developing clots up to one month after surgery. This review suggests that prophylaxis should be administered for at least one month after surgery.