Acute Kidney Injury After Total Arch Replacement Combined With Frozen Elephant Trunk Implantation: Incidence, Risk Factors, and Outcome

Machine learning-based model to predict severe acute kidney injury after total aortic arch replacement for acute type A aortic dissection

Background

Severe acute kidney injury (AKI) after total aortic arch replacement (TAAR) is related to adverse outcomes in patients with acute type A aortic dissection (ATAAD). However, the early prediction of severe AKI remains a challenge. This study aimed to develop a novel model to predict severe AKI after TAAR in ATAAD patients using machine learning algorithms.

Methods

A total of 572 ATAAD patients undergoing TAAR were enrolled in this retrospective study, and randomly divided into a training set (70 %) and a validation set (30 %). Lasso regression, support vector machine-recursive feature elimination and random forest algorithms were used to screen indicators for severe AKI (defined as AKI stage III) in the training set, respectively. Then the intersection indicators were selected to construct models through artificial neural network (ANN) and logistic regression. The AUC-ROC curve was employed to ascertain the prediction efficacy of the ANN and logistic regression models.

Results

The incidence of severe AKI after TAAR was 22.9 % among ATAAD patients. The intersection predictors identified by different machine learning algorithms were baseline serum creatinine and ICU admission variables, including serum cystatin C, procalcitonin, aspartate transaminase, platelet, lactic dehydrogenase, urine N-acetyl-β-d-glucosidase and Acute Physiology and Chronic Health Evaluation II score. The ANN model showed a higher AUC-ROC than logistic regression (0.938 vs 0.908, p < 0.05). Furthermore, the ANN model could predict 89.1 % of severe AKI cases beforehand. In the validation set, the superior performance of the ANN model was further confirmed in terms of discrimination ability (AUC = 0.916), calibration curve analysis and decision curve analysis.

Conclusion

This study developed a novel and reliable clinical prediction model for severe AKI after TAAR in ATAAD patients using machine learning algorithms. Importantly, the ANN model showed a higher predictive ability for severe AKI than logistic regression.

The role of serum magnesium in the prediction of acute kidney injury after total aortic arch replacement: A prospective observational study

Background

Considerable morbidity and death are associated with acute kidney damage (AKI) following total aortic arch replacement (TAAR). The relationship between AKI following TAAR and serum magnesium levels remains unknown. The intention of this research was to access the predictive value of serum magnesium levels on admission to the Cardiovascular Surgical Intensive Care Unit (CSICU) for AKI in patients receiving TAAR.

Methods

From May 2018 to January 2020, a prospective, observational study was performed in the Guangdong Provincial People's Hospital CSICU. Patients accepting TAAR admitted to the CSICU were studied. The Kidney Disease: Improving Global Outcomes (KDIGO) definition of serum creatinine was used to define AKI, and KDIGO stages two or three were used to characterize severe AKI. Multivariable logistic regression and area under the curve receiver-operator characteristic curve (AUC-ROC) analysis were conducted to assess the predictive capability of the serum magnesium for AKI detection. Finally, the prediction model for AKI was established and internally validated.

Results

Of the 396 enrolled patients, AKI occurred in 315 (79.5%) patients, including 154 (38.8%) patients with severe AKI. Serum magnesium levels were independently related to the postoperative AKI and severe AKI (both, P < 0.001), and AUC-ROCs for predicting AKI and severe AKI were 0.707 and 0.695, respectively. Across increasing quartiles of serum magnesium, the multivariable-adjusted odds ratios (95% confidence intervals) of postoperative AKI were 1.00 (reference), 1.04 (0.50-2.82), 1.20 (0.56-2.56), and 6.19 (2.02-23.91) (P for Trend < 0.001). When serum magnesium was included to a baseline model with established risk factors, AUC-ROC (0.833 vs 0.808, P = 0.050), reclassification (P < 0.001), and discrimination (P = 0.002) were further improved.

Conclusions

Serum magnesium levels on admission are an independent predictor of AKI. In TAAR patients, elevated serum magnesium levels were linked to an increased risk of AKI. In addition, the established risk factor model for AKI can be considerably improved by the addition of serum magnesium in TAAR patients hospitalized in the CSICU.

Exploring Acute Kidney Injury Following Aortic Dissection: A Comprehensive Review of Machine Learning Models for Predicting Risk, Management Strategies, Complications, and Racial and Gender Disparities

Both types of aortic dissection (AD), Stanford type A and type B, can result in complications such as acute kidney injury (AKI) and aortic rupture. Renal complications in AD arise from compromised renal perfusion affecting the renal arteries. Understanding the intricate connection between AD and AKI is crucial for navigating the complexities of tailored treatment and formulating specific management plans. Concerning machine learning models, in patients with type A aortic dissection, factors such as decreased platelet count on admission, increased D-dimer level, longer cardiopulmonary bypass duration, elevated white blood cell levels, the need for blood transfusion, longer aortic clamp time, extended surgery duration, advanced age, and an elevated body mass index were positively associated with the development of AKI. For the risk of AKI after type B aortic dissection, elevated Nt-pro brain natriuretic peptide, prolonged activated partial thromboplastin time, elevated admission systolic blood pressure, and a higher contrast agent requirement during operative repair were found to predict the risk. Male gender was associated with a higher risk of AKI, and nonwhite race was linked to a higher risk of AKI, a greater likelihood of requiring more urgent procedures, and lower levels of insurance coverage. The treatment of AKI following AD requires a multifaceted approach. Identifying and addressing the underlying cause, such as low blood pressure, renal artery involvement, or medication-induced injury, is crucial for effective management and preventing further kidney damage. Maintaining proper fluid balance is essential for improving renal perfusion, but careful monitoring is necessary to avoid complications. The evolving landscape of research, particularly in biomarkers and AI programs, reveals a promising role in predicting the risk for and managing AKI post-AD.

Safety and effectiveness of the sutureless integrated stented graft prosthesis in an animal model

Background

Prolonged circulatory arrest time is an independent risk factor for postoperative adverse events of type A aortic dissection (TAAD) surgery. Further reduction of the circulatory arrest time is essential to improve surgical outcomes. This study aimed to evaluate the safety and effectiveness of the novel Sutureless Integrated Stented (SIS) graft prosthesis in an animal experiment.

Materials and methods

Straight type of the SIS graft prosthesis was implanted into the descending aorta of 10 adult male sheep, and the use of the device was scored on a scale of 1-10. Aortic digital subtraction angiography (DSA) was performed at 4, 14, and 26 weeks to investigate the prostheses. After 26 weeks, the animals were sacrificed for histological analysis.

Results

The immediate success rate of the surgery was 100 %, and the overall mean score of the use of the device was 9.65 ± 0.99. Three animals died from non-device-related causes during follow-up. Aortic DSA showed filling defects in 5 animals. Histological analysis revealed that all prostheses were intact. Except for 2 early deaths, the other 8 prostheses were endothelialized with mild inflammation, foreign body reactions, and intimal fibrosis. The mean cross-sectional area of the sutureless region was reduced by 26.4 % (range, 1.3-39.1 %).

Conclusions

The safety and effectiveness of the novel SIS graft prosthesis were acceptable, and the delivery system exhibited a promising performance. Using the SIS graft prosthesis in TAAD surgery was expected to simplify the procedures and shorten the circulatory arrest time. Further large-scale clinical trials are required to verify these findings.

Risk factors for postoperative acute kidney injury in overweight patients with acute type A aortic dissection

OBJECTIVE

To analyze the clinical characteristics of patients with overweight acute type A aortic dissection, and to explore the risk factors of acute kidney injury in patients with overweight acute type A aortic dissection.

METHODS

From March 2019 to February 2022, the clinical data of 71 patients with acute type a aortic dissection diagnosed by CTA and undergoing surgical treatment with BMI > 24 in the First People's Hospital of Yunnan Province were retrospectively analyzed, and analyzed by univariate and logistic multivariate analysis methods.

RESULTS

The mean BMI of all included patients was 27.23, The mean surface area of all included human populations was 1.833. The mean age of all patients was (52.06 ± 10.71) years old, and 35 patients developed acute kidney injury after surgery. Multi-factor Logistics regression analysis confirmed the risk factors for postoperative acute kidney injury in overweight patients with acute type A aortic dissection, including gender, CPB transit time and intraoperative infusion of suspended red blood cells. Seven patients in the AKI group died in hospital after surgery and two patients died in the non-AKI group.

CONCLUSIONS

Among patients with overweight acute Type A aortic dissection, the incidence of AKI is 49.30%. According to multi-factor Logistics regression analysis, gender, CPB transit time and intraoperative suspended red blood cell volume are independent risk factors for postoperative acute kidney injury in patients with overweight acute Type A aortic dissection.

Association between preoperative serum myoglobin and acute kidney injury after Stanford Type A aortic dissection surgery

BACKGROUND

Acute kidney injury (AKI) is a common complication after Type A aortic dissection (TAAD) surgery, and it is associated with poor outcomes. The nephrotoxic effect of myoglobin was established, but its correlation with AKI following TAAD repair still lacks sufficient evidence. We clarified the correlation between preoperative serum myoglobin (pre-sMyo) concentrations and AKI after TAAD surgery.

METHOD

A retrospective analysis was performed on the perioperative data of 382 patients treated with TAAD surgery at Beijing Anzhen Hospital. AKI was defined and classified according to the criteria established by the Kidney Disease: Improving Global Outcomes Acute Kidney Injury Work Group. We attempted to determine the correlation between pre-sMyo concentrations and postoperative AKI.

RESULTS

The incidences of Stage 1, 2, and 3 AKI were 37.3 % (57/153), 23.5 % (36/153), and 39.2 % (60/153), respectively. The pre-sMyo concentrations of the AKI group were significantly increased than the non-AKI group [43.1 (21.4, 107.5) vs 26.4 (18.0, 37.2), P < 0.001]. Pre-sMyo concentrations have a linear correlation with preoperative renal function-related indicators. The multivariable logistic regression analysis showed that Ln (pre-sMyo) was an independent risk factor for AKI. When the pre-sMyo concentration was at the fourth quartile [109.3 (64.8, 213.4) ng/ml], the risk of developing any-stage and severe AKI was significantly increased (OR = 4.333, 95 % CI: 2.364-7.943, P < 0.001; OR = 3.862, 95 %, CI: 2.011-7.419, P < 0.001). This difference persisted after adjustment (OR = 3.830, 95 % CI: 1.848-7.936, P < 0.001; OR = 2.330, 95 % CI: 1.045-5.199, P = 0.039). Furthermore, pre-sMyo concentrations were not affected by lower limb malperfusion, myocardial malperfusion, and cardiac tamponade.

CONCLUSIONS

Increased pre-sMyo concentrations correlated with postoperative AKI in TAAD, which may increase the risk of developing any-stage AKI and severe AKI after TAAD surgery.

Prediction of acute kidney injury after total aortic arch replacement with serum cystatin C and urine N-acetyl-β-d-glucosaminidase: A prospective observational study

BACKGROUND

Acute kidney injury (AKI) after total aortic arch replacement (TAAR) is frequent and associated with adverse outcomes, whereas its early detection remains a challenge. Serum cystatin C (sCysC) and urinary N-acetyl-β-d-glucosaminidase (uNAG) are clinically available renal biomarkers, but their combination for AKI detection requires more evidence. This study aimed to assess the discriminative abilities of these biomarkers in AKI after TAAR.

MATERIALS AND METHODS

Patients undergoing TAAR were included in this prospective observational study. The AKI prediction model was developed and internal verificated, and the significance of each variable was analyzed by random forest (RF). Finally, the best predictive critical values of sCysC and uNAG were explored by the AUC-ROC curve.

RESULTS

The AUC-ROC of the prediction model was substantially enhanced by adding sCysC and uNAG (0.909 vs 0.844, p < 0.001), and the clinical utility and risk reclassification were significantly improved. Additionally, the RF showed that sCysC and uNAG ranked first and second. The AUC-ROC for each were 0.864 and 0.802 respectively, and the cut-off values were 1.395 mg/L and 31.90 U/g Cre respectively.

CONCLUSION

The prediction model incorporating functional marker sCysC and tubular injury marker uNAG can improve the discriminative abilities of AKI after TAAR.

Visceral protection in total arch replacement for aortic dissection: Effect of lower body hypothermia

OBJECTIVE

Optimal hypothermia strategy for total arch replacement in acute type A aortic dissection (ATAAD) is unclear. A higher temperature during circulatory arrest might reduce tolerance to ischemia for visceral organs. We sought to investigate the effect of hypothermia on visceral protection.

METHODS

From January 2010 to December 2019, 1138 consecutive patients underwent total arch replacement combined with frozen elephant trunk for acute type A aortic dissection. The data were retrospectively collected and analyzed. Visceral organ injury and visceral-related adverse outcomes were defined as acute renal failure or spinal cord injury or both. Multivariate logistic regression analysis and multivariate linear regression model were used.

RESULTS

The mean age of patient was 46.9 ± 10.0 years, with a male preponderance (79.6%). Operative mortality was 6.1% (69 patients). Spinal cord injury occurred in 55 (4.8%) patients and 133 (11.7%) patients had acute renal failure. In the multivariate logistic regression model, neither bladder temperature (odds ratio [OR] 0.971, 95% confidence interval [CI] 0.922-1.024, p = .278) nor circulatory arrest duration (OR 1.017, 95% CI 0.987-1.047, p = .267) significantly associated with visceral-related adverse outcomes. Female, lower limb malperfusion, age, cardiopulmonary bypass (CPB) duration and preoperative serum creatinine level were independent risk factors of visceral-related outcomes. There was a significant negative correlation between bladder temperature and CPB duration in multiple linear regression model (β = -3.67, p < .0001).

CONCLUSIONS

Bladder temperature had no effect on outcomes related to visceral protection under the premise of short circulatory arrest duration, but female gender, lower limb malperfusion, age, CPB duration, and preoperative serum creatinine level were independent risk factors. Bladder temperature negatively correlated to CPB duration.

Risk factors for acute kidney injury after Stanford type A aortic dissection repair surgery: a systematic review and meta-analysis

Background: Risk factors for acute kidney injury (AKI) after Stanford type A aortic dissection (TAAD) repair are inconsistent in different studies. This meta-analysis systematically analyzed the risk factors so as to early identify the therapeutic targets for preventing AKI.

Methods: Studies exploring risk factors for AKI after TAAD repair were searched from four databases from inception to June 2022. The synthesized incidence and risk factors of AKI and its impact on mortality were calculated.

Results: Twenty studies comprising 8223 patients were included. The synthesized incidence of postoperative AKI was 50.7%. Risk factors for AKI included cardiopulmonary bypass (CPB) time >180 min [odds ratio (OR), 4.89, 95% confidence interval (CI), 2.06–11.61, I² = 0%], prolonged operative time (>7 h) (OR, 2.73, 95% CI, 1.95–3.82, I² = 0), advanced age (per 10 years) (OR, 1.34, 95% CI, 1.21–1.49, I² = 0], increased packed red blood cells (pRBCs) transfusion perioperatively (OR, 1.09, 95% CI, 1.07–1.11, I² = 42%), elevated body mass index (per 5 kg/m²) (OR, 1.23, 95% CI, 1.18–1.28, I² = 42%) and preoperative kidney injury (OR, 3.61, 95% CI, 2.48–5.28, I² = 45%). All results were meta-analyzed using fixed-effects model finally (p < 0.01). The in-hospital or 30-day mortality was higher in patients with postoperative AKI than in that without AKI [risk ratio (RR), 3.12, 95% CI, 2.54–3.85, p < 0.01].

Conclusions: AKI after TAAD repair increased the in-hospital or 30-day mortality. Reducing CPB time and pRBCs transfusion, especially in elderly or heavier weight patients, or patients with preoperative kidney injury were important to prevent AKI after TAAD repair surgery.

Prediction model of acute kidney injury after different types of acute aortic dissection based on machine learning

Objective

A clinical prediction model for postoperative combined Acute kidney injury (AKI) in patients with Type A acute aortic dissection (TAAAD) and Type B acute aortic dissection (TBAAD) was constructed by using Machine Learning (ML).

Methods

Baseline data was collected from Acute aortic division (AAD) patients admitted to First Affiliated Hospital of Xinjiang Medical University between January 1, 2019 and December 31, 2021. (1) We identified baseline Serum creatinine (SCR) estimation methods and used them as a basis for diagnosis of AKI. (2) Divide their total datasets randomly into Training set (70%) and Test set (30%), Bootstrap modeling and validation of features using multiple ML methods in the training set, and select models corresponding to the largest Area Under Curve (AUC) for follow-up studies. (3) Screening of the best ML model variables through the model visualization tools Shapley Addictive Explanations (SHAP) and Recursive feature reduction (REF). (4) Finally, the pre-screened prediction models were evaluated using test set data from three aspects: discrimination, Calibration, and clinical benefit.

Results

The final incidence of AKI was 69.4% (120/173) in 173 patients with TAAAD and 28.6% (81/283) in 283 patients with TBAAD. For TAAAD-AKI, the Random Forest (RF) model showed the best prediction performance in the training set (AUC = 0.760, 95% CI:0.630–0.881); while for TBAAD-AKI, the Light Gradient Boosting Machine (LightGBM) model worked best (AUC = 0.734, 95% CI:0.623–0.847). Screening of the characteristic variables revealed that the common predictors among the two final prediction models for postoperative AKI due to AAD were baseline SCR, Blood urea nitrogen (BUN) and Uric acid (UA) at admission, Mechanical ventilation time (MVT). The specific predictors in the TAAAD-AKI model are: White blood cell (WBC), Platelet (PLT) and D dimer at admission, Plasma The specific predictors in the TBAAD-AKI model were N-terminal pro B-type natriuretic peptide (BNP), Serum kalium, Activated partial thromboplastin time (APTT) and Systolic blood pressure (SBP) at admission, Combined renal arteriography in surgery. Finally, we used in terms of Discrimination, the ROC value of the RF model for TAAAD was 0.81 and the ROC value of the LightGBM model for TBAAD was 0.74, both with good accuracy. In terms of calibration, the calibration curve of TAAAD-AKI's RF fits the ideal curve the best and has the lowest and smallest Brier score (0.16). Similarly, the calibration curve of TBAAD-AKI's LightGBM model fits the ideal curve the best and has the smallest Brier score (0.15). In terms of Clinical benefit, the best ML models for both types of AAD have good Net benefit as shown by Decision Curve Analysis (DCA).

Conclusion

We successfully constructed and validated clinical prediction models for the occurrence of AKI after surgery in TAAAD and TBAAD patients using different ML algorithms. The main predictors of the two types of AAD-AKI are somewhat different, and the strategies for early prevention and control of AKI are also different and need more external data for validation.

Zone proximalization in frozen elephant trunk: what is the optimal zone for open intervention? A systematic review and meta-analysis

INTRODUCTION

The treatment of complex aortic lesions involving the ascending, arch, and proximal descending aorta, remains challenging for surgeons despite the evolution of surgical techniques and aortic prostheses over decades. The frozen elephant trunk (FET) approach offers a one-stage repair of this entity of aortic pathologies. The main scope of this systematic review and meta-analysis is to evaluate the clinical outcomes and effectiveness of FET.

EVIDENCE ACQUISITION

In a systematic review, multiple electronic databases including EMBASE, Scopus, and PubMed/MEDLINE were searched from inception to June 2021 to identify relevant studies reporting on outcomes of total arch replacement (TAR) with FET.

EVIDENCE SYNTHESIS

Eighty-five studies met inclusion criteria, encompassing 10960 patients. Meta-analysis was conducted using the R-studio (RStudio, Boston, MA, USA) and STATA software (StataCorp LLC, College Station, TX, USA). The pooled in-hospital mortality rate was 7% (95% CI 0.05-0.09; I²=76%) and 12% for renal failure (95% CI 0.09-0.15; I²=88%), while the rates for paraplegia and cerebrovascular accidents were 3% (95% CI 0.02-0.04; I²=0%) and 6% (95% CI 0.05-0.08; I²=73%), respectively. Lower heterogeneity was attained after the stratification by the aortic pathologies, except for the renal failure. The distal anastomosis of the stent in zone 2 was significantly correlated with a lower renal failure development compared to zone 3 (odds ratio 0.52; 95% CI 0.33-0.82; P=0.069; I²=0%).

CONCLUSIONS

Our results indicate that the morbidities and mortality following TAR with FET were acceptable. We also associated the distal anastomosis in zone 2 with fewer renal failure development compared to that in zone 3.

Aortic Risks Prediction Models after Cardiac Surgeries Using Integrated Data

The complications of thoracic aortic disease include aortic dissection and aneurysm. The risks are frequently compounded by many cardiovascular comorbidities, which makes the process of clinical decision making complicated. The purpose of this study is to develop risk predictive models for patients after thoracic aneurysm surgeries, using integrated data from different medical institutions. Seven risk features were formulated for prediction. The CatBoost classifier performed best and provided an ROC AUC of 0.94–0.98 and an F-score of 0.95–0.98. The obtained results are widely in line with the current literature. The obtained findings provide additional support for clinical decision making, guiding a patient care team prior to surgical treatment, and promoting a safe postoperative period.

Serum Myoglobin Is Associated With Postoperative Acute Kidney Injury in Stanford Type A Aortic Dissection

Background

The correlation between rhabdomyolysis and postoperative acute kidney injury has been reported in several surgical procedures. As a good predictor of rhabdomyolysis-related acute kidney injury, an elevated serum myoglobin level was often observed after total aortic arch replacement combined with frozen elephant trunk implantation. However, the correlation between serum myoglobin and acute kidney injury in such patients had not been established.

Methods

Totally 398 stanford type A aortic dissection patients who underwent total aortic arch replacement combined with frozen elephant trunk implantation were enrolled in this retrospective study. The correlations between serum myoglobin and acute kidney injury as well as the 30-day mortality were assessed.

Results

Overall, 268(67.3%) patients had acute kidney injury (KDIGO stage 1 or higher) and 75(18.8%) had severe acute kidney injury (KDIGO stage 2&3). Patients who developed acute kidney injury had higher level of perioperative serum myoglobin than patients without acute kidney injury. After adjusting for known acute kidney injury risk factors, logarithmically transformed preoperative serum myoglobin [OR = 1.58 (95% CI, 1.26–1.95), P < 0.001] and postoperative day 1 serum myoglobin [OR = 3.47 (95%CI, 2.27–5.29), P < 0.001] were associated with severe acute kidney injury. These correlation persisted after adjustment for decline in filtration via change in serum creatinine (ΔCr) and biomarkers of cardiac and kidney injury, including N-terminal prohormone of brain natriuretic peptide, cardiac troponin I, creatine kinase-MB, serum creatinine and Cystatin C. Compared with the clinical model, sMb considerably improved the risk discrimination and reclassification for AKI.

Conclusion

For stanford type A aortic dissection patients underwent total aortic arch replacement with frozen elephant trunk implantation, serum myoglobin can improve postoperative acute kidney injury risk classification. Rhabdomyolysis may be an important supplement to the existing knowledge on the mechanism of acute kidney injury.

A Novel Sutureless Integrated Stented (SIS) Graft Prosthesis for Type A Aortic Dissection: A Pilot Study for a Prospective, Multicenter Clinical Trial

Aims

Various kinds of surgical strategies and prostheses have been advocated to improve short-term and long-term outcomes in type A aortic dissection (TAAD). Large-scale repair of the pathological aorta is hard to generalize due to complex procedures. We aimed to investigate the performance, effectiveness and safety of a novel Sutureless Integrated Stented (SIS) graft prosthesis in TAAD patients undergoing total arch replacement (TAR) and frozen elephant trunk (FET) implantation surgery.

Methods

All patients admitted to Fuwai Hospital were prospectively screened. Urgent or scheduled surgery was arranged for eligible patients. The primary endpoint was operative mortality. Key secondary endpoints included stroke, spinal cord injury, unexpected aortic reoperation, and 1-year survival. Discharged patients were followed up with computed tomography angiography and transthoracic echocardiography at 3 months, 6 months, and 1 year after surgery. Performance, effectiveness and safety analyses were performed in those patients.

Results

Between August 1 and September 3, 2020, ten TAAD patients were enrolled in this study and successfully implanted with the SIS graft prosthesis. The median (IQR) age was 56.50 (43.75, 66.75) years (range from 31 to 75), and seven patients were male (70.0%). All patients underwent ascending aorta replacement + TAR + FET and additional procedures when necessary. The median (IQR) operation time, cardiopulmonary bypass time and cross clamp time were 270.50 (218.50, 312.50), 110.00 (88.00, 125.75), 69.50 (51.25, 82.75) min, respectively. Of note, the median (IQR) circulatory arrest time was 9.00 (8.00, 9.00) min (range from 4 to 12). The median (IQR) lowest nasopharyngeal temperature was 26.75 (25.98, 27.67) °C. Follow-up was 100% completed. During the 1-year follow-up, no patients died, no severe adverse events occurred, and rate of freedom from aortic reintervention was 100%.

Conclusions

The SIS graft prosthesis was implanted in a novel sutureless way, which simplified the surgical procedure, shortened the circulatory arrest time and avoided deep hypothermia. The preliminary clinical outcomes and follow-up outcomes demonstrated the effectiveness and safety of this prosthesis. A large-scale trial is being conducted to further assess these findings.

Total Arch Replacement With Frozen Elephant Trunk Using a NEW “Brain-Heart-First” Strategy for Acute DeBakey Type I Aortic Dissection Can Be Performed Under Mild Hypothermia (≥30°C) With Satisfactory Outcomes

Background

Total arch replacement (TAR) with Frozen elephant trunk (FET) treatment of acute DeBakey type I aortic dissection (ADIAD) is complicated, carries a high complication/mortality risk and remains controversial on the optimal hypothermic level, cerebral perfusion and visceral organ protection strategy. We developed a new strategy named “Brain-Heart-first” in which the surgical procedures and the management of cardiac perfusion/cerebral protection during Cardiopulmonary bypass (CPB) were redesigned, and TAR with FET technique can be performed under mild hypothermia with satisfactory outcomes.

Objective

Our aims were to describe a new surgical strategy under mild hypothermia (≥30°C) for the treatment of ADIAD and to report the operative outcomes of 215 patients.

Methods

We conducted a retrospective analysis of 215 consecutive cases of ADIAD treated with our new strategy.

Results

The durations of CPB, aortic cross-clamping, antegrade cerebral perfusion, operation, mechanical ventilation support, and Intensive Care Unit stay were 139.7 ± 52.3 min, 55.6 ± 27.4 min, 14.1 ± 3.1 min, 6.0 ± 1.7 h, 40.0 h and 4.0 d, respectively. The 30-day mortality was 9.8%, with cerebral stroke occurring in nine patients (4.2%), paraplegia in one patient (0.5%) and postoperative renal injury requiring dialysis in 21 patients (9.8%). The blood transfusion of red blood cells and fresh frozen plasma during surgery and the first 24 h after surgery was 4.0 u and 200.0 ml, respectively.

Conclusions

The Brain-Heart-first strategy can be widely used with low technical and resource requirements and provides a safe alternative for conventional TAR with FET technique in ADIAD patients with satisfactory operative results.

Moderate and Deep Hypothermic Circulatory Arrest Have Comparable Effects on Severe Systemic Inflammatory Response Syndrome After Total Aortic Arch Replacement in Patients With Type A Aortic Dissection

Background: The objective of this study was to compare the incidence of severe systemic inflammatory response syndrome (sSIRS) after total aortic arch replacement between patients who underwent moderate hypothermic circulatory arrest (MHCA) and those who underwent deep hypothermic circulatory arrest (DHCA). Methods: At Fuwai Hospital, 600 patients who underwent total aortic arch replacement with MHCA or DHCA from January 2013 to December 2016 were consecutively enrolled and divided into DHCA (14.1-20.0°C) and MHCA (20.1-28.0°C) groups. Preliminary statistical analysis revealed that some baseline indicators differed between the two groups; therefore, propensity score matching (PSM) was used to balance the covariates. Post-operative sSIRS as the primary outcome was compared between the groups both before and after PSM. Results: A total of 275 (45.8%) patients underwent MHCA, and 325 (54.2%) patients underwent DHCA. After PSM analysis, a total of 191 matched pairs were obtained. The overall incidence of sSIRS was 27.3%. There was no significant difference in post-operative sSIRS between the MHCA group and the DHCA group in either the overall cohort or the PSM cohort (no-PSM: P = 0.188; PSM: P = 0.416); however, post-operative sSIRS was increased by ~4% in the DHCA group compared with the MHCA group in both the no-PSM and PSM cohorts (no-PSM: 29.5 vs. 24.7%; PSM: 29.3 vs. 25.1%). Both before and after PSM, the rates of gastrointestinal hemorrhage and pulmonary infection and post-operative length of stay were significantly increased in the DHCA group compared with the MHCA group (P < 0.05), and the remaining secondary outcomes were not significantly different between the groups. Conclusions: MHCA and DHCA are associated with comparable incidences of sSIRS in patients following total aortic arch replacement for type A aortic dissection. However, the MHCA group had a shorter cardiopulmonary bypass time, a shorter post-operative length of stay and lower pulmonary infection and gastrointestinal hemorrhage rates than the DHCA group. We cautiously recommend the use of MHCA for most total arch replacements in patients with type A aortic dissection.

Blood Transfusion and Acute Kidney Injury After Total Aortic Arch Replacement for Acute Stanford Type A Aortic Dissection

AIM

To evaluate the effect of packed red blood cells (pRBCs), fresh frozen plasma (FFP), and platelet concentrate (PC) transfusions on acute kidney injury (AKI) in patients with acute Stanford type A aortic dissection (ATAAD) with total arch replacement (TAR).

METHOD

From December 2015 to October 2017, 421 consecutive patients with ATAAD undergoing TAR were included in the study. The clinical data of the patients and the amount of pRBCs, FFP, and PC were collected. Acute kidney injury was defined using the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Logistic regression was used to identify whether pRBCs, FFP, and platelet transfusions were risk factors for KDIGO AKI, stage 3 AKI, and AKI requiring renal replacement therapy (RRT).

RESULTS

The mean ± standard deviation age of the patients was 47.67±10.82 years; 77.7% were men; and the median time from aortic dissection onset to operation was 1 day (range, 0-2 days). The median transfusion amount was 8 units (range, 4-14 units) for pRBCs, 400 mL (range, 0-800 mL) for FFP, and no units (range, 0-2 units) for PC. Forty-one (41; 9.7%) patients did not receive any blood products. The rates of pRBC, PC, and FFP transfusions were 86.9%, 49.2%, and 72.9%, respectively. The incidence of AKI was 54.2%. Considering AKI as the endpoint, multivariate logistic regression showed that pRBCs (odds ratio [OR], 1.11; p<0.001) and PC transfusions (OR, 1.28; p=0.007) were independent risk factors. Considering KDIGO stage 3 AKI as the endpoint, multivariate logistic regression showed that pRBC transfusion (OR, 1.15; p<0.001), PC transfusion (OR, 1.28; p<0.001), a duration of cardiopulmonary bypass (CPB) ≥293 minutes (OR, 2.95; p=0.04), and a creatinine clearance rate of ≤85 mL/minute (OR, 2.12; p=0.01) were independent risk factors. Considering RRT as the endpoint, multivariate logistic regression showed that pRBC transfusion (OR, 1.12; p<0.001), PC transfusion (OR, 1.33; p=0.001), a duration of CPB ≥293 minutes (OR, 3.79; p=0.02), and a creatinine clearance rate of ≤85 mL/minute (OR, 3.34; p<0.001) were independent risk factors.

CONCLUSIONS

Kidney Disease: Improving Global Outcomes-defined stage AKI was common after TAR for ATAAD. Transfusions of pRBCs and PC increased the incidence of AKI, stage 3 AKI, and RRT. Fresh frozen plasma transfusion was not a risk factor for AKI.

Risk factors of mortality in AAAD patients who had severe postoperative hyperbilirubinemia and received CRRT

OBJECTIVE

Severe acute kidney injury (AKI) and hyperbilirubinemia increase the morbidity and mortality risk in patients undergoing emergency surgery for acute type A aortic dissection (AAAD). Our purpose was to investigate the risk factors of mortality in AAAD surgery patients who had severe postoperative hyperbilirubinemia and AKI receiving continuous renal replacement therapy (CRRT).

METHODS

Patients who had severe hyperbilirubinemia and received CRRT after AAAD surgery in our center between January 2015 and December 2018 were retrospectively screened. Univariate and multivariate analyses were performed to identify the risk factors of in-hospital mortality. Kaplan-Meier curves were employed to evaluate the accumulated patient survival proportion.

RESULTS

After screening, 50 patients were included in our present study. The in-hospital mortality was 84%. The univariate logistic analysis showed that preoperative MAP (p = .017) and peak total bilirubin concentration (p < .001) were associated with in-hospital mortality in AAAD surgery patients who had severe postoperative hyperbilirubinemia and received CRRT. Multivariate logistic regression analysis revealed that the peak bilirubin concentration (odds ratio, 1.050; 95% confidence interval, 1.002-1.101; p = .041) after surgery was the only independent risk factor for in-hospital mortality. The optimal cutoff value of peak bilirubin for predicting in-hospital mortality was 134.4 μmol/L.

CONCLUSIONS

AAAD surgery patients with severe hyperbilirubinemia and AKI requiring CRRT had a poor prognosis. Increased postoperative peak bilirubin concentration strongly increased the risk of patient in-hospital mortality. Therefore, these patients should be closely monitored and treated aggressively when possible.

Mild hypothermic circulatory arrest with selective cerebral perfusion in open arch surgery

Background

This study aimed to evaluate whether the use of mild hypothermic circulatory arrest (HCA) with selective cerebral perfusion (SCP) in open arch procedure provides comparable perioperative results to moderate HCA for patients with dissected or degenerative arch pathologies.

Methods

Between January 2017 and September 2020, a total of 88 consecutive patients (mean age 47±11 years, 71 males) underwent open arch repair under a single surgeon at our institution with mild or moderate systemic hypothermia assisted by unilateral or bilateral SCP. Patients were divided into groups according to the nasopharyngeal temperature at the beginning of HCA: a moderate HCA group (n=47, 53.4%) and a mild HCA group (n=41, 46.6%). The postoperative mortality, morbidity, and visceral organ functions between these groups were analyzed retrospectively.

Results

Compared to the moderate HCA group, the mild HCA group had a significantly higher core temperature (nasopharynx: 24.4±0.8 vs. 28.5±2, P<0.001; bladder 25.9±0.9 vs. 30±1.2, P<0.001), and the incidence of major adverse events (MAE) in this group was markedly lower (21.3% vs. 4.9%, P=0.031). No differences were identified between the two groups refer to in-hospital mortality, permanent neurological deficit (PND), temporary neurological deficit (TND), and paraplegia (8.5% vs. 2.4%, P=0.366; 8.5% vs. 0, P=0.120; 6.4% vs. 7.3%, P=1.0; 4.3% vs. 2.4%, P=1.0, respectively). In the moderate HCA group, 6 patients (12.8%) developed acute renal failure needing replacement therapy, which did not occur in the mild HCA group (P=0.028). The duration of ventilator support and intensive care unit stay was shorter in the mild HCA group, as well as a decreased volume of drainage during the first 24 h and reduced platelet transfusion.

Conclusions

The preliminary results of the mild HCA group with SCP applied in open arch repair, mainly in total arch replacement (TAR) and stented elephant trunk (SET) implantation for aortic dissection, were satisfactory. Furthermore, comparable inferior outcomes were obtained with mild HCA compared with that of the conventional moderate HCA strategy. These encouraging surgical and postoperative results favor this more aggressive hypothermia strategy in open arch repair.

Impact of autologous platelet rich plasma use on postoperative acute kidney injury in type A acute aortic dissection repair: a retrospective cohort analysis

BACKGROUND

Perioperative coagulopathy and blood transfusion are common in patients undergoing Stanford type A acute aortic dissection (AAD) repair. The autologous platelet-rich plasmapheresis (aPRP) technique is a blood conservation approach to reduce blood transfusions and morbidity in patients at high risk of bleeding. The purpose of this study was to analyze the effect of aPRP on outcomes, especially in postoperative acute kidney injury (post-AKI), in patients undergoing AAD surgery.

METHODS

Six hundred sixty patients were divided into aPRP and non-aPRP groups according to aPRP use. The primary endpoint was the difference in the incidence of post-AKI between two groups. The secondary endpoints were risk factors for post-AKI and to assess clinical outcomes. The risk factors associated with post-AKI were calculated, and all outcomes were adjusted by propensity-score matching analysis.

RESULTS

A total of 272 patients (41.2%) received aPRP, whereas 388 were in the non-aPRP group. Compared to non-aPRP group, the occurrence of post-AKI increased by 14.1% (p = 0.002) and 11.1% (p = 0.010) with and without propensity adjustment in the aPRP group, respectively. The aPRP group required fewer intraoperative transfusions (p < 0.05) and shortened the duration of mechanical ventilation (p < 0.05) than those in the non-aPRP group. Multiple regression analyses showed that aPRP (odds ratio: 1.729, 95% confidence interval: 1.225-2.440; p < 0.001) was one of the independent risk factors for post-AKI.

CONCLUSIONS

The use of aPRP significantly reduced intraoperative blood transfusions and decreased postoperative mortality-adjusted mechanical ventilation. However, aPRP use was independently associated with an increased hazard of post-AKI after adjusting for confounding factors.

[Predictors of early adverse events after the frozen elephant trunk procedure]

AIM

The aim of this study was to identify predictors of adverse events after the frozen elephant trunk procedure in the early postoperative period.

PATIENTS AND METHODS

Between March 2012 and March 2020, a total of 273 patients were operated on for aortic pathology. A retrospective analysis aimed at identifying probable predictors was performed on 83 patients who underwent the FET procedure. Uni- and multivariate logistic regression was used to identify predictors of such adverse events as postoperative delirium, respiratory failure, acute kidney injury, and in-hospital mortality.

RESULTS

According to the findings of the optimal multivariate regression model, separate reimplantation of the supra-aortic branches was a significant predictor of postoperative delirium (OR 10.41; 95% CI 1.1-35.45; p=0.05); significant risk factors for prolonged respiratory support were the duration of surgery (OR 1.02; 95% CI 1.01-1.03; p<0.001) and postoperative acute renal injury (OR 8.72; 95% CI 1.67-57.38; p=0.014). Independent risk factors for postoperative renal injury turned out to be the true lumen diameter of the descending aorta (OR 1.3; 95% CI 1.1-1.72; p=0.015) and chronic type A aortic dissection (OR 44.07; 95% CI 3.29-2354.8; p=0.014); statistically significant risk factors for in-hospital mortality were multiple organ dysfunction syndrome (OR 14.34; 95% CI 1.69-155.48; p=0.016) and coronary artery stenosis (OR 3.36; 95% CI 1.19-13.26; p=0.042).

CONCLUSION

Separate reimplantation of the supra-aortic branches, duration of surgery, acute kidney injury, chronic aortic dissection, multiple organ dysfunction syndrome, true lumen diameter of the descending aorta, coronary atherosclerosis and haemoglobin level were statistically significant predictors of adverse events in the early postoperative period.

Intraoperative blood transfusion volume is an independent risk factor for postoperative acute kidney injury in type A acute aortic dissection

BACKGROUND

Type A acute aortic dissection is a life-threatening disease associated with adverse clinical outcomes. Acute kidney injury (AKI) is common after surgery. However, the relationship between intraoperative blood transfusion and postoperative AKI remains unclear.

METHODS

The records of 130 patients who underwent type A acute aortic dissection surgery from January 2015 to December 2018 were retrospectively analyzed. According to the Kidney Disease Improving Global Outcomes criteria, postoperative AKI was defined based on serum creatinine concentration. Multivariable logistic regression analysis was applied to estimate the independent association between intraoperative blood transfusion volume and the risk of postoperative AKI.

RESULTS

Postoperative AKI was observed in 82 patients (63.08%). The in-hospital mortality was 16.15% (n = 21). Multivariate logistic regression showed that the amount of intraoperative blood transfusion was independently associated with the risk of postoperative AKI in a dose-dependent manner. Every 200 ml increment of blood transfusion volume was associated with a 31% increase in AKI risk (odds ratio 1.31 and 95% confidence interval 1.01-1.71).

CONCLUSIONS

Intraoperative transfusion volume may increase the incidence of postoperative AKI. The mechanism and influence of transfusion thresholds on AKI need to be explored in the future.

Risk factors analysis of acute kidney injury following open thoracic aortic surgery in the patients with or without acute aortic syndrome: a retrospective study

Background

The acute kidney injury (AKI) remains a frequent complication following open thoracic aortic surgery (OTAS) and worsens the postoperative prognosis. It remains unclear that whether the predictors of AKI following OTAS are different in the patients with or without acute aortic syndrome (AAS).

Methods

Preoperative and intraoperative variables were compared between the patients with or without AKI, and were further analyzed for identifying the potential predictors of postoperative AKI. Subgroup analysis was conducted in the patients with or without AAS, respectively.

Results

AKI after OTAS occurred in 57.6% of the overall cohort, 70.1% of the patients with AAS and 46.7% of the patients without AAS. In the multivariate analysis, history of hypertension (OR 1.011, 95% CI: [1.001–1.022], p = 0.04), preoperative platelet (OR 0.995, 95% CI: [0.991–0.999], p = 0.006) and operation time (OR 1.572, 95% CI: [1.355–1.823], p < 0.001) were identified as independent predictors of postoperative AKI for the overall cohort; CPB time (OR 1.020, 95% CI: [1.009–1.031], p < 0.001) and preoperative LMR (OR 0.823, 95% CI: [0.701–0.966], p = 0.02) as independent predictors for the patients with AAS; age (OR 1.045, 95% CI: [1.015–1.076], p = 0.003), preoperative platelet (OR 0.993, 95% CI: [0.988–0.998], p = 0.04) and operation time (OR 1.496, 95% CI: [1.166–1.918], p = 0.002) as independent predictors for the patients without AAS.

Conclusions

The patients with AAS carry a higher risk for postoperative AKI compared with those without AAS. The predictive factors for postoperative AKI after OTAS are different for AAS- and non-AAS subgroups and operation time, CPB time and preoperative platelet are modifiable predictors of AKI.

Characteristics and outcomes of Stanford type A aortic dissection patients with severe post-operation hyperbilirubinemia: a retrospective cohort study

BACKGROUND

Hyperbilirubinemia is one of the common complications after cardiac surgery and is associated with increased mortality. However, to the best of our knowledge, the reports on clinical significance of postoperative severe hyperbilirubinemia in Stanford type A aortic dissection (AAD) patients were limited.

METHODS

Patients who underwent surgical treatment for AAD in our center between January 2015 and December 2018 were retrospectively screened. In-hospital mortality, long-term mortality, acute kidney injury (AKI), and the requirement of continuous renal replacement therapy (CRRT) were assessed as endpoints. Univariate and multivariate regression models were employed to identify the risk factors of these endpoints.

RESULTS

After screening, 271 patients were included in our present study. Of the included patients, 222 (81.9%) experienced postoperative AKI, and 50 (18.5%) received CRRT. The in-hospital mortality was 30.3%. The 1-year, 2-year, and 3-year cumulative mortality were 32.9, 33.9, and 35.3%, respectively. Multivariate Logistic regression analysis indicated that age (P < 0.033), AKI stage 3 (P < 0.001), the amount of blood transfusion after surgery (P = 0.019), mean arterial pressure (MAP) in the first postoperative day (P = 0.012), the use of extracorporeal membrane oxygenation (ECMO) (P = 0.02), and the peak total bilirubin (TB) concentration (P = 0.023) were independent risk factors of in-hospital mortality. The optimal cut-off value of peak TB on predicting in-hospital mortality was 121.2 μmol/L. Patients with post-operation TB ≥ 121 μmol/L was associated with worse long-term survival as well.

CONCLUSIONS

Severe post-operation hyperbilirubinemia is a common clinical situation in patients had AAD repair. In AAD patients with severe post-operation hyperbilirubinemia, older age, lower MAP, increased blood transfusion, stage 3 AKI, the use of ECMO, and the increased peak TB lead to increase in-hospital mortality.

90 days impacts of remote ischemic preconditioning on patients undergoing open total aortic arch replacement: a post-hoc analysis of previous trial

Background

In the previous randomized controlled trial by our research group, we evaluated the effect of remote ischemic preconditioning (RIPC) in 130 patients (65 per arm) on acute kidney injury (AKI) within 7 days of open total aortic arch replacement. Significantly fewer RIPC-treated patients than sham-treated patients developed postoperative AKI, and, epically, RIPC significantly reduced serious AKI (stage II–III). However, the long-term effect of RIPC in patients undergoing open total aortic arch replacement is unclear.

Methods

This study was a post-hoc analysis. We aimed to assess the roles of RIPC in major adverse kidney events (MAKE), defined as consisting persistent renal dysfunction, renal replacement therapy and mortality, within 90 days after surgery in patients receiving open total aortic arch replacement.

Results

In this 90-day follow-up study, data were available for all study participants. We found that RIPC failed to improve the presence of MAKE within 90 days after surgery (RIPC: 7 of 65[10.8%]) vs sham: 15 of 65[23.1%]; P = 0.061). In those patients who developed AKI after surgery, we found that the rate of MAKE within 90 days after surgery differed between the RIPC group and the sham group (RIPC: 4 of 36[11.2%]; sham: 14 of 48[29.2%]; P = 0.046).

Conclusions

At 90 days after open total aortic arch replacement, we failed to find a difference between the renoprotective effects of RIPC and sham treatment. The effectiveness or ineffectiveness of RIPC should be further investigated in a large randomized sham-controlled trial.

Trial registration

This study was approved by the Ethics Committee of Fuwai Hospital (No. 2016–835) and our previous study was registered at clinicaltrials.gov before patient enrollment (NCT03141385; principal investigator: G.W.; date of registration: March 5, 2017).

Renal protective effect of the aortic balloon occlusion technique in total arch replacement with frozen elephant trunk

Background

Organ dysfunction caused by hypothermic circulatory arrest continues to concern surgeons. The aortic balloon occlusion (ABO) technique can significantly shorten the circulatory arrest time in total arch replacement with frozen elephant trunk (TAR with FET). This study aims to analyze the renal protective effect of the ABO technique and to analyze the predictors of acute kidney injury (AKI) and continuous renal replacement therapy (CRRT) after TAR with FET.

Methods

Between August 2017 and September 2018, 247 patients who underwent TAR with FET were divided into ABO and moderate hypothermic circulatory arrest (MHCA) groups. The primary endpoint was postoperative AKI defined by the Kidney Disease Improving Global Outcomes (KDIGO) criteria. Multivariable logistic analysis was used to identify the predictors of AKI and CRRT after TAR with FET.

Results

With the application of the ABO technique, the circulatory arrest time was significantly shortened (ABO 4, IQR: 3-6 vs. MHCA 18, IQR: 16-20, P<0.001). Meanwhile, surgeons safely set the lowest nasopharyngeal temperature at a higher grade (ABO 28.1, IQR: 27.4-28.5 vs. MHCA 24.7, IQR: 24.1-25.1, P<0.001). The peak serum creatinine (SCr) values within 48 hours after the surgery was lower in the ABO group than in the MHCA group (ABO 124, IQR: 97-173 vs. MHCA 146, IQR: 108-221, P=0.008). The distribution of AKI grade according to the KDIGO criteria differed between the two groups (P=0.04): more patients in the ABO group were free from AKI (Grade 0) than patients in the MHCA group (33% vs. 23.1%), and the proportion of patients with high-grade AKI (Grades 2 and 3) in the ABO group was lower than that in the MHCA group (21% vs. 32%). The ABO technique was associated with reduced potential for AKI, but was not protective for CRRT.

Conclusions

The ABO technique significantly shortened the circulatory arrest time and safely elevated temperature, and provided better renal protection in patients undergoing TAR with FET. The ABO technique did not reverse the need for CRRT, nor did it reduce mortality or major adverse events.

Effect of dexmedetomidine on acute kidney injury after aortic surgery: a single-centre, placebo-controlled, randomised controlled trial

BACKGROUND

Acute kidney injury (AKI) is a frequent and serious complication after aortic surgery requiring cardiopulmonary bypass (CPB). Dexmedetomidine, a selective α-2 adrenoreceptor agonist, may reduce AKI because of its sympatholytic and anti-inflammatory effects against ischaemia-reperfusion injury. We investigated the effect of dexmedetomidine administration on AKI after aortic surgery requiring CPB in a placebo-controlled randomised controlled trial.

METHODS

A total of 108 patients were randomly assigned to an infusion of dexmedetomidine or saline at a rate of 0.4 μg kg-1 h-1 for 24 h starting after anaesthetic induction. The primary outcome was the incidence of AKI, as defined by the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. The secondary outcomes included delirium and major morbidity. Safety outcomes were drug-related adverse events (bradycardia, hypotension).

RESULTS

AKI occurred in 7/54 (13%) subjects randomised to dexmedetomidine, compared with 17/54 (31%) subjects randomised to saline infusion (odds ratio=0.32; 95% confidence interval [CI], 0.12-0.86; P=0.026). Secondary outcomes, including stroke, mortality, and delirium, were similar between subjects randomised to dexmedetomidine (16/54 [30%] or saline control (22 [41%]; odds ratio=0.61 [95% CI, 0.28-1.36]). The incidence of bradycardia and hypotension was similar between groups (14/54 (26%) vs. 17/54 (32%) (odds ratio:0.76 (95%CI:0.33-1.76) and 29/54 (54%) vs. 36/54 (67%) (odds ratio:0.58 (95%CI:0.27-1.26), respectively). The length of hospital stay was shorter in the dexmedetomidine group (12 [10-17] days) vs saline control (15 [11-21] days; P=0.039).

CONCLUSIONS

Pre-emptive dexmedetomidine administration for 24 h starting after induction of anaesthesia reduced the incidence of AKI after aortic surgery requiring CPB, without any untoward side-effects related to its sedative or sympatholytic effects.

CLINICAL TRIAL REGISTRATION

NCT02607163 (www.

CLINICALTRIALS

gov).

Inflammatory biomarkers to predict adverse outcomes in postoperative patients with acute type A aortic dissection

Objectives. The present study aimed to evaluate prognostic value of inflammatory markers for in-hospital mortality and renal complication in patients undergoing surgery for acute type A aortic dissection (ATAAD). Design. Serum concentration of C-reactive protein, leukocyte counts, procalcitonin (PCT), tumor necrosis factor (TNF)-α, interleukin-2 receptor (IL-2R), IL-6 and IL-8 were measured on the day of admission to the hospital (T0) and on 1st (T1), 2nd (T2), and 7th (T3) day after surgery. Results. 328 patients were included. There were significant differences between survivor group and non-survivor group in PCT, IL-2R, and IL-6 (p = .001, p = .015, and p = .005). There were significant differences between patients with different AKI stage in PCT and IL-2R (p = .001, p < .001). The area under receiver operating characteristics (ROC) curve on 30-day death was 0.686 for PCT, 0.718 for IL-2R, 0.694 for IL-6 and 0.627 for IL-8. The area under ROC curve on stage III AKI was 0.852 for PCT, 0.749 for IL-2R, 0.626 for IL-8, and 0.636 for TNF-α. IL-2 > 1438 U/ml and IL-6 > 45.5 pg/ml were independently associated with 30-day mortality (p = .014 and p < .001). The area under ROC curve was 0.849 on score 2 (using 1 point for PCT > 4.58 ng/ml, 1 point for IL-2R > 1438 U/ml, 1 point for APACHE II score >15.5, and 1 point for IL-6 > 45.5 pg/ml). Conclusions. PCT and cytokines may be considered as predictors for adverse renal outcomes and mortality in patients with ATAAD patients after surgery. They are earlier than traditional biomarkers and combination of these biomarkers will improve the accuracy.

Remote Ischemic Preconditioning Prevents Postoperative Acute Kidney Injury After Open Total Aortic Arch Replacement: A Double-Blind, Randomized, Sham-Controlled Trial

BACKGROUND

Acute kidney injury is a common complication after open total aortic arch replacement but lacks effective preventive strategies. Remote ischemic preconditioning has controversial results of its benefit to the kidney and may perform better in high-risk patients of acute kidney injury. We investigated whether remote ischemic preconditioning would prevent postoperative acute kidney injury after open total aortic arch replacement.

METHODS

We enrolled 130 patients scheduled for open total aortic arch replacement and randomized them to receive either remote ischemic preconditioning (4 cycles of 5-minute right upper limb ischemia and 5-minute reperfusion) or sham preconditioning (4 cycles of 5-minute right upper limb pseudo ischemia and 5-minute reperfusion), both via blood pressure cuff inflation and deflation. The primary end point was the incidence of acute kidney injury within 7 days after the surgery defined by the Kidney Disease: Improving Global Outcomes criteria. Secondary end point included short-term clinical outcomes.

RESULTS

Significantly fewer patients developed postoperative acute kidney injury with remote ischemic preconditioning compared with sham (55.4% vs 73.8%; absolute risk reduction, 18.5%; 95% CI, 2.3%-34.6%; P = .028). Remote ischemic preconditioning significantly reduced acute kidney injury stage II-III (10.8% vs 35.4%; P = .001). Remote ischemic preconditioning shortened the mechanical ventilation duration (18 hours [interquartile range, 14-33] versus 25 hours [interquartile range, 17-48]; P = .01), whereas no significant differences were observed between groups in other secondary outcomes.

CONCLUSIONS

Remote ischemic preconditioning prevented acute kidney injury after open total aortic arch replacement, especially severe acute kidney injury and shortened mechanical ventilation duration. The observed renoprotective effects of remote ischemic preconditioning require further investigation in both clinical research and the underlying mechanism.

Early outcome of aortic balloon occlusion during total aortic arch replacement with the frozen elephant trunk technique for aortic dissection

OBJECTIVES

The aim of this study was to propose and evaluate the new operative technique of aortic balloon occlusion in total aortic arch replacement (TAR) with the frozen elephant trunk that can significantly decrease the time of circulatory arrest and increase the hypothermic cardiopulmonary bypass (CPB) temperature.

METHODS

Between 2010 and 2018, 1335 patients with aortic dissection who underwent TAR with the frozen elephant trunk were included in the study. The newest 80 cases were treated with aortic balloon occlusion. To illustrate the difference with the new procedure, 1255 conventional TAR cases served as the historical control. Femoral and right axillary artery cannulations were used for CPB and antegrade selective cerebral perfusion. Circulatory arrest was implemented at the nasopharyngeal temperature of 28°C with continuous antegrade selective cerebral perfusion. After the stent graft was inserted into the true lumen of the descending aorta, the aortic balloon in a sheath was deployed into the stent graft and positioned at the metal part of the stent graft. When the balloon was inflated with enough saline to compress the stent graft, the sheath was simultaneously pressed by hand to properly fix the balloon and avoid displacement. Then femoral perfusion could be resumed.

RESULTS

The aortic balloon occlusion technique was successful in all patients, with the median duration of circulatory arrest being 5 (interquartile range 3-7) min. The 30-day mortality rate was 6.25% (5/80), whereas with the conventional method it was 9.40% (118/1255). The postoperative conscious revival (8.67 vs 11.40 h, P < 0.001) and mechanical ventilation times (19.70 vs 24.45 h, P = 0.02) were significantly shorter. Decreases in postoperative acute kidney injuries (13.75% vs 32.11%, P = 0.001) and liver injuries (8.75% vs 37.61%, P < 0.001) were also observed. The patients were transfused with lesser quantities of red blood cells, plasma and platelets.

CONCLUSIONS

The aortic balloon occlusion technique is a feasible way to shorten circulatory arrest significantly, to obviate the need for deep hypothermia in TAR with the frozen elephant trunk and to provide favourable protective effects on the central nervous, haematological and visceral systems. With these satisfactory results, this technique deserves further investigation.

Preoperative platelet count, preoperative hemoglobin concentration and deep hypothermic circulatory arrest duration are risk factors for acute kidney injury after pulmonary endarterectomy: a retrospective cohort study

Background

Acute kidney injury (AKI) is a major postoperative morbidity of patients undergoing cardiac surgery and has a negative effect on prognosis. The kidney outcomes after pulmonary endarterectomy (PEA) have not yet been reported; However, several perioperative characteristics of PEA may induce postoperative AKI. The objective of our study was to identify the incidence and risk factors for postoperative AKI and its association with short-term outcomes.

Methods

This was a single-center, retrospective, observational, cohort study. Assessments of AKI diagnosis was executed based on the Kidney Disease Improving Global Outcomes (KDIGO) criteria.

Results

A total of 123 consecutive patients who underwent PEA between 2014 and 2018 were included.

The incidence of postoperative AKI was 45% in the study population. Stage 3 AKI was associated with worse short-term outcomes and 90-day mortality (p < 0.001, p = 0.002, respectively). The independent predictors of postoperative AKI were the preoperative platelet count (OR 0.992; 95%CI 0.984–0.999; P = 0.022), preoperative hemoglobin concentration (OR 0.969; 95%CI 0.946–0.993; P = 0.01) and deep hypothermic circulatory arrest (DHCA) time (OR 1.197; 95%CI 1.052–1.362; P = 0.006) in the multivariate analysis.

Conclusion

The incidence of postoperative AKI was relatively high after PEA compared with other types of cardiothoracic surgeries. The preoperative platelet count, preoperative hemoglobin concentration and DHCA duration were modifiable predictors of AKI, and patients may benefit from some low-risk, low-cost perioperative measures.

Moderate and deep hypothermic circulatory arrest has a comparable effect on acute kidney injury after total arch replacement with frozen elephant trunk procedure in type A aortic dissection

OBJECTIVES

The goal was to investigate the prevalence of acute kidney injury (AKI) after total arch replacement with frozen elephant trunk procedure, which was achieved by antegrade cerebral perfusion and moderate hypothermic circulatory arrest (MHCA) or deep hypothermic circulatory arrest (DHCA) among patients with type A aortic dissection.

METHODS

Overall, 627 adult type A aortic dissection patients who underwent total arch replacement with frozen elephant trunk from January 2013 until December 2016 at Fuwai Hospital were divided into the DHCA (14.1-20.0°C) and MHCA (20.1-28.0°C) groups. Postoperative AKI as the primary outcome was compared using propensity-matched scoring.

RESULTS

Overall, 340 (54.2%) and 287 (45.8%) patients underwent DHCA and MHCA, respectively. The overall incidence of AKI was 75.4%. Age [odds ratio (OR) 1.02, 95% confidence interval (CI) 1.00-1.04; P = 0.022], body mass index (OR 1.06, 95% CI 1.01-1.12; P = 0.016), cardiopulmonary bypass duration (OR 1.01, 95% CI 1.00-1.01; P = 0.003) and hypertension history (OR 1.76, 95% CI 1.14-2.70; P = 0.010) were identified as independent risk factors for AKI onset with multivariable analysis. Postoperative AKI was not significantly different between the DHCA and MHCA groups regardless of the overall or propensity-matched cohort (overall data: P = 0.17; propensity score data: P = 0.88). Patients with MHCA experienced higher rates of postoperative stroke after propensity score analysis (DHCA 0.9% vs MHCA 3.7%; P = 0.034).

CONCLUSIONS

MHCA was not superior to DHCA in decreasing postoperative AKI. Thus, MHCA should not definitively replace DHCA.