Analysis Of The Liver Abscess And Its Risk Factors After Microwave Ablation Treatment Of Liver Cancer

Background and AimsMicrowave ablation is one of the most important local treatment methods for liver cancer,and it is recommended as a radical therapy for liver cancer in many guidelines.For the early stage of liver cancer,microwave ablation has similar effect to that of surgical resection.The incidence of major complications was only 4.6(0.7-11.8)%,and ablation related mortality was 0.23(0.1-0.58)%.Even though the major complication rate of microwave ablation of liver cancer is not high,it will have a serious impact on the survival of patients,especially the patients with liver abscess after ablation that often die due to poor treatment effect,so it is extremely important to take measures to prevent the occurrence of major complications of microwave ablation or to intervene it as early as possible.Moreover,at present only a few published researches are about major complications of microwave ablation in the treatment of liver cancer.The sample is small and the risk factors of major complications are still not clear.Furthermore,the results of different studies on major complications after microwave ablation are lack of effective comparability due to the differences in study design,selection criteria,patient characteristics and other aspects.Therefore,by means of this study we hope to make clear the incidence of the major complications of microwave ablation,to find out the characteristics and regularity of the occurrence of major complications,to explore the influencing factors of major complications,and to further analyze the risk factors and predictors of liver abscess after treatment of microwave ablation so as to improve the quality of microwave ablation treatment of liver cancer,to provide a theoretical support for reducing the incidence of major complications,and to guide the further optimization of microwave ablation procedures.MethodsFirstly,we retrospectively analyzed the liver cancer cases treated with microwave ablation of our unit from January 2010 to November 2015 by using the electronic medical records system and follow-up data to collect the information of the major complications after operation.Secondly,the detailed characteristics and risk factors of major complications were summarized and analysed.Thirdly,through the method of constructing a case-control study,we explored the risk factors and predictors of liver abscess after treatment of microwave ablation.Finally,the ability of predictors to predict the occurrence of liver abscess was calculated by the receiver operating characteristic curve.Results1.According to the inclusion and exclusion criteria,a total of 7403 patients with 12558 microwave ablation procedures were enrolled in this study.The incidence of major complications rate was 1.3%(96/7403),and the microwave ablation related mortality was 0.07%(5/7403);2.There were 34 cases(0.46%)of liver abscess,20 cases(0.27%)of pleural effusion,15 cases(0.2%)of bile duct injury,6 cases(0.08%)of bleeding among the major complications,and liver failure,adjacent organ injury,tumor seeding and other major complications were rare;3.The major complications occurred most frequently 24 hours to 1 month after the ablation procedure,and the bacteria of liver abscess often come from the gastrointestinal tract;4.The tumor type and the year of microwave ablation therapy may be the risk factors of major complications and the P value is 0.002 and 0.003 respectively;5.Diabetes Mellitus and a history of biliary tract surgery are the risk factors of liver abscess after microwave ablation treatment of liver cancer with Odds Ratio 6.3[95%CI(1.1-35.8),P = 0.037] and 19.0[95%CI(1.5-237.9),P = 0.022];6.The percentage of neutrophils at the first day after microwave ablation procedure was the predictor of liver abscess with Odds ratio 1.3,95% CI(1,1.6),P value 0.019;7.ROC curve analysis showed that the cut off value of the percentage of neutrophil at the first day after microwave ablation procedure was 75.4.AUC was 0.8,95%CI(0.7145,0.8869),specificity was 60.29% and sensitivity was 88.2%.According to the cut off values,the patients were divided into two groups,and there was obvious statistical significance(value of 2 =21.653,P<0.001)in the incidence of liver abscess.Conclusion1.Microwave ablation is a safe and effective local ablation therapy for liver cancer;2.Liver abscess is the most common major complication after treatment of microwave ablation of liver cancer,which was followed by pleural effusion.Bile duct injury,bleeding,adjacent organ damage,vascular thrombosis,tumor seeding and other major complications are rare;3.Major complications mainly occurred 24 h to 1 month after microwave ablation,so not only the long-term observation of patients after microwave ablation cannot be ignored,but also a close follow-up during the first key month is needed;4.The occurrence of major complications may be related to the operator's experience and tumor type.Therefore,the risk of major complications could be effectively avoided through some appropriate measures;5.Diabetes Mellitus and a history of biliary tract surgery are risk factors for liver abscess after microwave ablation treatment of liver cancer;6.The percentage of neutrophils at the first day after microwave ablation procedure is the predictor of liver abscess;7.For the patients with a percentage of neutrophils that exceeds 75.4 on the first day,the hospital observation time should be prolonged so as to leave enough time for some assistant examination of early diagnosis and early targeted interference measures.