Complications After Total Arch Replacement With A Stented Elephant Trunk For Type A Acute Aortic Dissection

BackgroundAortic dissection can be divided into two categories by Stanford classification,including type A and type B.The 30-day fatality rate for patients with type A dissection is about 4 times as type B dissection.Type A acute aortic dissection is one of the most medical emergency for its high mortality and morbidity.Total arch replacement surgery with a stented elephant trunk is recommended for most of patients.The patients underwent total arch replacement surgery for type A acute aortic dissection(AAD)often complicated with severe systemic pathophysiological changes which led to severe multi-system and multi-organ perioperative complications.Oxygenation impairment is a common complication post type A AAD surgery.Oxygenation impairment,as manifested by hypoxemia,is associated with the oxygen supply for the whole body.Long-term serious oxygen supply deficient to multiple organs may lead functional impairments,an increase in healthcare costs,and in the most severe cases,mortality.Total arch replacement surgery with a stented elephant trunk is likely to be associated with more visceral organ dysfunction than other cardiac surgery,because of ischemia reperfusion injury caused by the lower body circulatory arrest.The overall incidence of acute kidney injury(AKI)after aortic surgery has been reported to be high compared with other cardiac operations.AKI after surgery is associated with a higher risk for postoperative renal replacement therapy(RRT)and even a higher risk for mortality in thoracic aortic surgery.Therefore,it is of utmost importance to identify risk factors for oxygenation impairment and AKI after surgery of type A AAD to reduce perioperative complications and improve surgical treatment effects by early intervention and treatment of the complications.In our study,we evaluated risk factors of postoperative oxygenation impairment and AKI in type-A AAD after total arch replacement.PART 1 MODERATE TO SEVERE OXYGENATION IMPAIRMENT AFTER TOTAL ARCH REPLACEMENT WITH A STENTED ELEPHANT TRUNK FOR TYPE A ACUTE AORTIC DISSECTIONObjective:The present study evaluated the incidence and risk factors of moderate to severe oxygenation impairment in type A AAD patients who underwent total arch replacement with a stented elephant trunk.Furthermore,the mechanical ventilation time,intensive care unit(ICU)stay,hospital stay,incidence of the hospital acquired pneumonia and death were compared between oxygenation impairment and non-oxygenation impairment patients.Methods:In this study,169 consecutive patients were enrolled who were diagnosed with type A AAD and underwent a total arch replacement with a stented elephant trunk procedure at the Qilu Hospital of Shan dong University from First January 2015 to 28th February 2017.Moderate to severe oxygenation impairment after surgery was defined as PaO2/FiO2 ? 200 with PEEP ? 5 cmH2O that occurred within 72 hour of surgery.Perioperative clinical characteristics of all patients were collected and univariable analyses were performed between the oxygenation impairment group and non-oxygenation impairment group.Risk factors associated with moderate to severe oxygenation impairment identified by univariable analyses were included in the multivariable regression analysis.The prediction model was then established upon acquired independent risk factors.The model was then tested for calibration(by comparing the observed and predicted oxygenation impairment)and for discrimination(using the area under the Receiver operating characteristic curve).Goodness of fit of the final model was tested using the Hosmer-Lemeshow statistic.Results:The incidence of postoperative oxygenation impairment was 48.5%.95.1%(n =78)patients with moderate to severe oxygenation impairment were identified within 12h of surgery,and the duration of oxygenation impairment ranged from 12 hours to more than 72 hours.Multivariabe regression analysis demonstrated that body mass index(odds ratio[OR]=1.204,95%confidence interval[CI]1.065-1.361,p=0.003),preoperative oxygenation impairment(OR =9.768,95%Cl 4.159-22.941,P<0.001),preoperative homocysteine(OR =1.080,95%CI 1.006-1.158,p =0.032),circulatory arrest time(OR =1.123,95%Cl 1.044-1.207,p=0.002),and plasma transfusion(OR =1.002,95%CI 1.001-1.003,p =0.002)were significant associated with moderate to severe oxygenation impairment after surgery.According to the Hosmer and Lemeshow goodness of fit p =0.684>0.05,and an area under the Receiver operating characteristic curve of 0.878>0.5,the prediction model successfully predicted the incidence of moderate to severe oxygenation impairment after surgery.Postoperative moderate to severe oxygenation impairment was significant associated with a prolonged mechanical ventilation time(hours)[(59.0,34.0-88.1)vs(17.5,13.5-34.0)],ICU stay(hours)[(153.5,129.3-205.0)vs(103.0,79.5-125.0)],and hospital stay(days)[(20.0,16.8-24.0)vs(17.0,15.0-19.0)].Although moderate to severe oxygenation impairment associated with the higher incidence of the hospital-acquired pneumonia,the rate of death was not increased.Conclusions:Moderate to severe oxygenation impairment is a common complication after surgery for type A AAD,and was associated with prolonged ventilation time,extended ICU and hospital stays,and a higher incidence of hospital-acquired pneumonia.Body mass index,preoperative oxygenation impairment,preoperative homocysteine,circulatory arrest time,and plasma transfusion were independent risk factors for moderate to severe oxygenation impairment after total arch replacement procedure.The prediction model established upon acquired independent risk factors can successfully predicate the incidence of postoperative moderate to severe oxygenation impairment.Early discovery,early diagnosis,early treatment of oxygenation impairment,controlling inflammatory reactions,reducing postoperative plasma transfusion,and shortening of the circulatory arrest time may contribute to improving the postoperative clinical course of patients underwent total arch replacement with a stented elephant trunk surgery for type A AAD.PART 2 ACTUE KIDNEY INJURY AFTER TOTAL ARCH REPLACEMENT WITH A STENTED ELEPHANT TRUNK FOR TYPE A ACUTE AORTIC DISSECTIONObjective:To study the incidence and risk factors for acute kidney inj ury(AKI)in type A AAD patients who underwent total arch replacement with a stented elephant trunk.Methods:In this study,176 consecutive patients were enrolled who were diagnosed with type A AAD and underwent a total arch replacement procedure at the Qilu Hospital of Shan dong University from January 2015 to February 2017.AKI was diagnosed with the Kidney Disease Improving Global Outcomes(KDIGO)criteria with minor modifications.Perioperative clinical characteristics of all patients were collected and univariable analyses were performed.Risk factors associated with AKI identified by univariable analyses were included in the multivariable regression analysis.The Receiver operating characteristic curve was used to identify the cut-off value for predicting postoperative AKI and renal replacement therapy.Results:The incidence of postoperative AKI was 71%.A significant higher incidence of death were observed in patients with a stage 3 AKI.Multivariabe regression analysis demonstrated that body mass index(OR =1.144,95%CI 1.023-1.278,p =0.018),gender(OR =3.160,95%CI 1.403-7.116,p =0.005),Preoperative serum creatinine(?mol/l)(OR =1.024,95%CI 1.009-1.038,p=0.001),Cardiopulmonary bypass time(minutes)(OR =1.010,95%CI 1.001-1.020,p = 0.030)were significant postoperative AKI risk factors.Conclusions:Postoperative AKI is a very common complication for type A acute aortic dissection.Body mass index,gender,preoperative serum creatinine levels,and Cardiopulmonary bypass time were independent risk factors for AKI after total arch replacement procedure.