Interventions for preventing venous thromboembolism in adults undergoing knee arthroscopy

 

Abstract

Background

Knee arthroscopy is a frequent surgical procedure. Arthroscopy procedures are considered minimally invasive. However, some patients will need extended surgical time, suffer injury and immobilization thus increasing the risk for thromboembolic events. Incidence of deep venous thrombosis (DVT) in patients undergoing knee arthroscopy is reported to be from 0.6% to 17.9% depending on the diagnostic method used. Different approaches are available for thromboprophylaxis (mechanical or pharmacological).

Objectives

To assess the effectiveness and safety of thromboprophylaxis to reduce the incidence of DVT in patients undergoing knee arthroscopy.

Search methods

We searched the Cochrane Peripheral Vascular Diseases Group Specialized Register (last searched October 2006) the CENTRAL (last searched Issue 4, 2006), MEDLINE (1966 to 2006), EMBASE (1980 to 2006), and Lilacs (1988 to 2006). We contacted specialists known to be involved in phlebology and interested in post thrombotic syndrome for details of unpublished and ongoing trials.

Selection criteria

Randomized clinical trials (RCTs) and controlled clinical trials (CCTs), whether blinded or not (i.e. double blinded, single blinded or unblinded) of all type of interventions, whether mechanical or pharmacological, single or in combination, used to prevent DVT in males and females over 18 years old undergoing knee arthroscopy. There was no restriction on language.

Data collection and analysis

Two authors independently assessed trial quality and extracted data. Study authors were contacted for additional information.

Main results

Four trials involving 527 predominantly male participants were included. The main weakness of the studies was the lack of correct stratification of the arthroscopic intervention.

The relative risk (RR) of thrombotic events was 0.16 (95% confidence interval (CI); 0.05 to 0.52) comparing any type of low molecular weight heparin (LMWH) versus placebo. All thrombotic events but one (pulmonary embolism in the LMWH group) were distal venous thrombosis. Adverse events were most common in the intervention group than in the control group, RR 2.04 (95% CI 1.21 to 3.44). There were 66 episodes of adverse events. The number needed to harm was 20 for any adverse events.

Authors' conclusions

This meta-analysis suggests that LMWH reduces the incidence of distal DVT diagnosed by sonogram. The clinical benefit of this is uncertain. No strong evidence was found to conclude thromboprophylaxis is effective to prevent thromboembolic events and safe, in people with unknown risk factors for thrombosis, undergoing knee arthroscopy.

 

Plain language summary

Interventions for preventing venous thromboembolism in adults undergoing knee arthroscopy

Knee arthroscopy is a common, minimally invasive surgical procedure used both for diagnosis and treatment of knee conditions. It is increasingly carried out in day surgery using various types of anaesthesia. Some people are at increased risk of developing deep vein thrombosis (DVT) because of factors including a previous history, immobilization, smoking, obesity, varicose veins and increasing age. Different approaches are available for preventing DVT (thromboprophylaxis), both mechanically and with drug medication. The characteristic symptoms of DVT are limb pain and swelling (edema) but often there are no obvious signs or symptoms. DVT at or above knee level (proximal) is associated with an increased risk of pulmonary embolism (which can be fatal) but isolated calf DVT (distal) rarely causes symptoms and is asymptomatic. Arthroscopy patients are often young and soon become mobile again. The incidence of DVT is reported to be from 0.6% when diagnosed clinically to 17.9% using the most sensitive imaging techniques (venography).

This review reports that low molecular weight heparin reduces the incidence of distal DVT diagnosed but the clinical benefits of this are uncertain. The review authors identified four completed studies from three countries that randomly assigned a total of 527 adults to low molecular weight heparin (LMWH) or no intervention or placebo. The mean age of participants ranged from 31 to 44 years and nearly three quarters were male. The relative risk (RR) of thrombotic events was 0.16 (range 0.05 to 0.52). The number needed to treat to prevent one thrombotic event was 17. All the blood clots were distal and were mainly diagnosed by sonogram. Adverse events were most common in the intervention group. The most common complication was minor bleeding with a RR of 2.23 (range 0.99 to 4.99). The number needed to harm was 20. No completed studies were found that looked at mechanical devices such as graduated elastic stockings or intermittent pneumatic compression, for patients immobilized in bed.

 

摘要

背景

接受膝關節鏡手術(knee arthroscopy)的成人患者預防靜脈栓塞的介入治療方法

膝關節鏡手術是一種十分常見的外科手術，也是一種微創手術，但是有些病患需要較長的手術時間，並且受到一些損傷或是無法移動，因此會增加出現栓塞事件的風險，接受膝關節鏡手術的病患受到所使用治療方法的影響而使得發生深部靜脈栓塞的機率介於0.6%至17.9%之間，有許多不同方法可以用預防栓塞現象(使用機械性或藥物性方法)。

目標

評估栓塞預防對於降低接受膝關節鏡手術病患發生深部靜脈栓塞的有效性和安全性。

搜尋策略

我們搜尋 Cochrane Peripheral Vascular Diseases Group Specialized Register (最後一次搜尋為2006年10月)、CENTRAL (最後一次搜尋為 Issue 4, 2006年)、MEDLINE (1966年 2006年)、EMBASE (1980年∼2006年)，以及Lilacs (1988年∼2006年)。我們與靜脈學且研究興趣在於栓塞後症候群的知名專家聯絡，藉此取得未發表及正在進行中的試驗。

選擇標準

接受過膝關節鏡手術之18歲以上男女性患者，不管是否為盲性試驗(也就是包括雙盲、單盲和非盲性試驗)、不管使用機械性或藥物性(使用單一藥物或複合藥物)的所有類型之介入治療，來比較預防發生深部靜脈栓塞的隨機性對照試驗和對照性臨床試驗。沒有語言上的限制。

資料收集與分析

有2名作者獨立的評估試驗品質和取出數據，連繫研究作者來取得更多資訊。

主要結論

有4個包括527名以男性為多數之受試者的試驗被納入，研究的主要缺點是缺乏對於關節鏡介入治療的正確分層。相較於安慰劑而言，任何類型的低分子量肝素所引發栓塞事件較少，相對風險(RR值)為0.20(95%信賴區間(CI) = 0.07 – 0.57)。除了一個個案(低分子量肝素組有一例發生肺動脈栓塞)之外，其他所有栓塞事件都是遠端靜脈栓塞(distal venous thrombosis)。在介入治療組發生副作用的機率比對照組更多，RR值2.11(95% CI值介於1.26 – 3.55)，一共出現了66次的副作用，任何一次副作用發生所需要治療的病人數目為20人。

作者結論

統合分析結果顯示，低分子量肝素會降低遠端深部靜脈栓塞(經由超音波診斷)的發生率，但是其臨床效益目前仍無法確定。沒有發現強烈的證據可以斷定對於那些沒有栓塞風險的患者在進行膝關節鏡手術時，栓塞預防是一種有效且具有安全性的方法。

翻譯人

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

總結

用來預防接受膝關節鏡手術成人發生靜脈栓塞的介入療法。膝關節鏡手術是一種常見的微創手術，其可以用來診斷和治療膝蓋的狀況，現在在手術中，很多類型的麻醉藥劑使用有增多的趨勢，有些患者發生深部靜脈栓塞的風險較高，例如先前之病史、無法移動、吸菸、肥胖、靜脈曲張和年紀大等因素。有許多不同方法可以用來預防深部靜脈栓塞(栓塞預防)，其中包括了機械性和藥物治療方法。深部靜脈栓塞的特徵是肢體疼痛和腫脹(水腫)，但經常是沒有明顯的症狀產生。發生在膝蓋或是膝蓋以上(近端)的深部靜脈栓塞會增加引發肺動脈栓塞(可能會致命)的風險，但是單獨的小腿深部靜脈栓塞(遠端)極少產生症狀，通常是無症狀的。關節鏡手術患者通常為年輕人且可以很快的恢復行動力。深部靜脈栓塞的發生率由靠臨床診斷的0.6%，至利用靈敏度最高的影像技術(靜脈造影，venography)的17.9%不等。本回顧提出了低分子量肝素可以降低遠端深部靜脈栓塞的發生率，但是其臨床效益尚未明瞭。本回顧的作者確認了由3個國家取得的4個完整的研究，這些研究係隨機納入527名成人患者，將使用低分子量肝素與不進行介入性治療或是使用安慰劑來做比較，患者平均年齡介於31至44歲之間，且將近3/4為男性，發生栓塞的RR值為0.20(介於0.07至0.57之間)，需要進行治療以預防1名病患發生栓塞事件的人數是17人，所有的血塊都位在遠端，且主要是由超音波進行診斷。 在介入治療發生不良事件是十分普遍，最主要的併發症是小型出血症狀，RR值為2.41(由1.08至5.36之間)，發生1次副作用所需要進行治療的病人數目為20人。缺乏完整的研究去探討例如梯度式彈性襪或間歇性充氣加壓治療(Intermittent pneumatic compression, IPC)等機械性裝置對於臥床無法移動的患者的效果。