人工膝関節全置換術における出血対策―術中トラネキサム酸使用の効果

The Intraoperative Administration of Tranexamic Acid Reduces Blood Loss in Total Knee Arthroplasty

　抄録：人工膝関節全置換術（以下TKA）において，術中・術後出血は不可避であり，その対策については，さまざまな方法が報告されてきた．今回われわれはTKA施行時の出血量を減少させる目的で，トラネキサム酸を術中（駆血帯解除15分前から解除までの間）に投与し，出血量を抑制できるかどうかについて検討した．対象は，TKA初回手術41症例で，トラネキサム酸術中投与群21例，非投与群20例の2群に分類した．総出血量（術中および術後出血の合計）は，投与群平均479ml（56ml～828ml），非投与群平均1159ml（455ml～2080ml）と，2群間において有意差を認め，投与群ではほぼ全例で輸血を回避することが可能であった．トラネキサム酸の術中投与は，特別な器具や手技を必要としない簡便な方法であり，コストも安く，TKAにおける出血対策として非常に有用な方法であると考えられた．

　Intraoperative and postoperative bleeding in total knee arthroplasty (TKA) is inevitable and several methods to reduce the perioperative blood loss have been reported. Here we investigated the effect of intraoperative administration of tranexamic acid (TA) on blood loss associated with TKA. Before deflation of the tourniquet, 1000mg of TA was given intravenously for 15minutes. Forty-one patients who underwent the primary TKA were evaluated in a retrospective study. Twenty-one patients received TA and the remaining 20 patients formed a control group. The average amount of total blood loss was significantly less (p＜0.001) in the TA group compared with the control group (479ml vs 1159ml). In the TA group, no patient required postoperative homologous blood transfusions except one patient. Eleven patients in the control group needed homologous blood transfusions and eight patients of the remaining nine in the control group received autologous blood transfusions. No patient in the both group had a complication, including a deep venous thrombosis. We conclude that intraoperative administration of TA is very effective to reduce TKA-associated blood loss and transfusion requirements.