Gurusamy Kurinchi Selvan, Li Jun, Sharma Dinesh, Davidson Brian R
University Department of Surgery, Royal Free Hospital and University College School of Medicine, 9th Floor, Royal Free Hospital, Pond Street, London, UK, NW3 2QG.
Cochrane Database Syst Rev. 2009 Oct 7(4):CD007338. doi: 10.1002/14651858.CD007338.pub2.
Blood loss during liver resection is one of the most important factors affecting the peri-operative outcomes of patients undergoing liver resection.
To determine the benefits and harms of cardiopulmonary interventions to decrease blood loss and to decrease allogeneic blood transfusion requirements in patients undergoing liver resections.
We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index Expanded until November 2008 for identifying the randomised trials.
We included all randomised clinical trials comparing various cardiopulmonary interventions aimed at decreasing blood loss and allogeneic blood transfusion requirements in liver resection. Trials were included irrespective of whether they included major or minor liver resections, normal or cirrhotic livers, vascular occlusion was used or not, and irrespective of the reason for liver resection.
Two authors independently identified trials for inclusion and independently extracted data. We analysed the data with both the fixed-effect and the random-effects models using RevMan Analysis. For each outcome we calculated the risk ratio (RR), mean difference (MD), or standardised mean difference (SMD) with 95% confidence intervals (CI) based on intention-to-treat analysis or available case-analysis. For dichotomous outcomes with only one trial included under the outcome, we performed the Fisher's exact test.
Nine trials involving 587 patients satisfied the inclusion criteria. The interventions included low central venous pressure (CVP), autologous blood donation, haemodilution, haemodilution with controlled hypotension, and hypoventilation. Only one or two trials were included under most comparisons. All trials had a high risk of bias. There was no significant difference in the peri-operative mortality or other peri-operative morbidity. None of the trials reported long-term survival or liver failure.The risk ratio of requiring allogeneic blood transfusion was significantly lower in the haemodilution and haemodilution with controlled hypotension groups than the respective control groups. Other interventions did not show significant decreases of allogeneic transfusion requirements.
AUTHORS' CONCLUSIONS: None of the interventions seem to decrease peri-operative morbidity or offer any long-term survival benefit. Haemodilution shows promise in the reduction of blood transfusion requirements in liver resection surgery. However, there is a high risk of type I (erroneously concluding that an intervention is beneficial when it is actually not beneficial) and type II errors (erroneously concluding that an intervention is not beneficial when it is actually beneficial) because of the few trials included, the small sample size in each trial, and the high risk of bias. Further randomised clinical trials with low risk of bias and random errors assessing clinically important outcomes such as peri-operative mortality are necessary to assess any cardiopulmonary interventions aimed at decreasing blood loss and blood transfusion requirements in liver resections. Trials need to be designed to assess the effect of a combination of different interventions in liver resections.
肝切除术中的失血是影响肝切除患者围手术期结局的最重要因素之一。
确定心肺干预措施在减少肝切除患者失血及降低异体输血需求方面的益处和危害。
我们检索了Cochrane肝胆组对照试验注册库、Cochrane图书馆中的Cochrane对照试验中央注册库（CENTRAL）、MEDLINE、EMBASE以及科学引文索引扩展版，检索截至2008年11月，以识别随机试验。
我们纳入了所有比较旨在减少肝切除术中失血及异体输血需求的各种心肺干预措施的随机临床试验。无论试验是否纳入了大或小的肝切除术、正常或肝硬化肝脏、是否使用血管阻断，以及肝切除的原因，均纳入试验。
两位作者独立确定纳入试验并独立提取数据。我们使用RevMan分析软件，采用固定效应模型和随机效应模型对数据进行分析。对于每个结局，我们基于意向性分析或现有病例分析，计算风险比（RR）、均值差（MD）或标准化均值差（SMD）及95%置信区间（CI）。对于某结局下仅纳入一项试验的二分结局，我们进行Fisher精确检验。
九项涉及587例患者的试验符合纳入标准。干预措施包括低中心静脉压（CVP）、自体血捐献、血液稀释、控制性低血压下的血液稀释以及低通气。大多数比较下仅纳入了一两项试验。所有试验均存在较高偏倚风险。围手术期死亡率或其他围手术期并发症方面无显著差异。没有试验报告长期生存情况或肝衰竭情况。血液稀释组和控制性低血压下血液稀释组中需要异体输血的风险比显著低于各自的对照组。其他干预措施未显示异体输血需求有显著降低。
似乎没有任何一种干预措施能降低围手术期并发症或带来任何长期生存益处。血液稀释在减少肝切除手术输血需求方面显示出前景。然而，由于纳入试验数量少、每个试验样本量小以及偏倚风险高，存在I型错误（错误地得出某干预措施有益而实际上并无益处）和II型错误（错误地得出某干预措施无益处而实际上有益）的高风险。有必要开展偏倚风险和随机误差低的进一步随机临床试验，评估诸如围手术期死亡率等临床重要结局，以评估任何旨在减少肝切除术中失血和输血需求的心肺干预措施。试验需要设计成评估不同干预措施联合在肝切除术中的效果。
