Acute kidney injury during aortic arch surgery under deep hypothermic circulatory arrest

Quantifying the effects of circulatory arrest on acute kidney injury in aortic surgery

OBJECTIVES

We aim to investigate the association between parameters surrounding circulatory arrest and postoperative acute kidney injury in aortic surgery.

METHODS

This is a single-center retrospective study of 1118 adult patients who underwent aortic repair with median sternotomy between January 2010 and May 2019. Acute kidney injury was defined on the basis of a modified version of the 2012 Kidney Disease Improving Global Outcomes Scale that excluded urine output. The primary outcome of interest was any stage of acute kidney injury.

RESULTS

Circulatory arrest was required in 369 patients, and 307 patients (27.5%) developed acute kidney injury: stage 1 in 241 patients, stage 2 in 38 patients, and stage 3 in 28 patients. Lower-body ischemia (the period during circulatory arrest without blood flow to kidneys) duration was not associated with acute kidney injury after multivariable logistic regression (1-40 minutes, odds ratio, 0.67; 95% confidence interval, 0.43-1.04; P = .075; >40 minutes, odds ratio, 0.67; 95% confidence interval, 0.29-1.55; P = .356). Hypertension (odds ratio, 1.65; 95% confidence interval, 1.09-2.54; P = .020), preoperative estimated glomerular filtration rate (odds ratio, 0.99; 95% confidence interval, 0.98-1.00; P = .010), packed red blood cell transfusion volume (odds ratio, 1.00; 95% confidence interval, 1.00-1.00; P = .028), and nadir temperature (odds ratio, 0.93; 95% confidence interval, 0.88-0.99; P = .013) were independently associated with acute kidney injury after multivariable analysis. Although there was a positive association between lower-body ischemia duration and development of acute kidney injury with univariable cubic spline, the positive curve was flattened after adjustment for the described variables.

CONCLUSIONS

Within the range of our clinical practice, prolonged lower-body ischemia duration was not independently associated with postoperative acute kidney injury, whereas nadir temperature was.

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.

Impact of hyperbilirubinemia associated acute kidney injury on chronic kidney disease after aortic arch surgery: a retrospective study with follow-up of 1-year

BACKGROUND

Hyperbilirubinemia (HB) is a serious complication in aortic arch surgery, which is associated with acute kidney injury (AKI). The association between HB and chronic kidney disease (CKD) is unknown. The aim of this study was to investigate the impact of HB associated AKI on CKD after aortic arch surgery.

METHODS

We reviewed 284 patients who underwent aortic arch surgery from 2016 to 2020 in our hospital. AKI was defined as a 50% increase in sCr from baseline value within the first 7 postoperative days. HB was defined as total bilirubin > 51.3 μmol/L. Patients were divided into 3 groups based on AKI and HB: HB associated AKI (HB-AKI) group (AKI patients suffered HB within the first 7 postoperative days); AKI without HB group and Non-AKI group.

RESULTS

Follow-up for 204 patients ranged from 3 to 12 months. Kaplan-Meier analysis showed that the 1-year cumulative incidence of CKD was highest in HB-AKI (32.6%) than AKI without HB (17.8%) and Non-AKI (7.4%, log-rank test, p < 0.001), and the incidence of CKD was higher in HB group than that in Non-HB group (26.7% vs. 13.9%, log-rank test, p = 0.015). Preoperative sCr (HR 1.010, 95% CI 1.004-1.016, p = 0.001), AKI without HB (HR 2.887, 95% CI 1.133-7.354, p = 0.026) and HB-AKI (HR 4.490, 95% CI 1.59-12.933, p = 0.005) were associated with CKD during 1-year follow-up.

CONCLUSIONS

Patients suffering HB associated AKI were at more increased odds of CKD than patients suffering AKI without HB after aortic arch surgery.

Post-Operative Kidney Function Using Deep Hypothermic Circulatory Arrest (DHCA) in Aortic Arch Operation

Background

Although deep hypothermic circulatory arrest (DHCA) is a useful option to protect the central nervous system during aortic arch operations, the influence of simultaneous renal ischemia remains controversial.

Patients and Methods

This is a retrospective observational study. Sixty-three patients who underwent thoracic aortic surgery with DHCA and 24 patients who underwent cardiac surgery without DHCA were included in this study. The mean age, preoperative serum creatinine (Cr) level, preoperative estimated glomerular filtration rate (eGFR), peak serum Cr level up to 48 hrs post-operative, elevation rate of Cr compared to the preoperative serum Cr, urine volume rate up to 48 hrs post-operative and AKI staging using the KDIGO criteria were estimated for each patient. Clinical parameters for 3 months after the operation and the 3-month post-operative mortality rate were assessed. Mean values indicating kidney function or distribution of the AKI stages were compared between patients with and without DHCA. Patients with DHCA were further divided according to the duration of ischemia to compare the values for the kidney function of each group, distribution of AKI stages and mortality.

Results

The parameters indicating AKI of the patients with DHCA were significantly more severe than those without DHCA. Patients who had undergone an ischemic state for more than 40 min revealed significantly higher peak serum Cr, elevation rate of serum Cr, less urine volume up to 48 hrs post-operative compared with those without DHCA. Distribution of the AKI stages was related to the duration of ischemia. The 3-month post-operative mortality of the patients with DHCA was significantly higher than those without DHCA.

Limitations

This study had limitations such as its retrospective design and small number patients, and the data will be required confirmation with other prospective studies.

Conclusion

DHCA is closely related to AKI up to 48 hrs post-operative and death during the 3 months following surgery.

Perioperative Outcomes for Radical Nephrectomy and Level III-IV Inferior Vena Cava Tumor Thrombectomy in Patients with Renal Cell Carcinoma

OBJECTIVES

This study examined the characteristics, intraoperative, and postoperative course of patients undergoing inferior vena cava tumor thrombectomy for metastatic renal cell carcinoma.

DESIGN

A single-center case series that reported demographic data and intraoperative and postoperative outcomes for patients with renal cell carcinoma undergoing inferior vena cava thrombectomy.

SETTING

This investigation was performed at a large quaternary referral center.

PARTICIPANTS

Adult patients (age ≥18) admitted to the authors' hospital from January 1, 2005, to March 10, 2017, undergoing inferior vena cava thrombectomy for level III and IV renal cell carcinoma.

INTERVENTIONS

No interventions were performed.

MEASUREMENTS AND MAIN RESULTS

Sixty-five patients who met the inclusion criteria were identified, with 31 patients diagnosed with level III and 34 with level IV renal cell carcinoma. Patients with level IV tumors were significantly more likely to have greater intraoperative blood loss, had longer surgical duration and hospital stays, and had more frequently required blood products, pressors, and cardiopulmonary bypass intraoperatively. Intraoperative transesophageal echo was more frequently used in level IV thrombectomy compared to level III (91.2% v 67.7%). Of patients with level IV thrombus, 41.2% developed postoperative atrial fibrillation compared to only 3.2% with level III thrombus. The 30-day mortality was 4.6% for both groups.

CONCLUSIONS

Patients undergoing inferior vena cava tumor thrombectomy for renal cell carcinoma had more complex intraoperative and postoperative courses with level IV compared to level III tumor thrombus.

Plasma levels of receptor-interacting protein kinase 3 is associated with postoperative acute kidney injury in acute DeBakey type I aortic dissection

Background

Postoperative acute kidney injury (AKI) in acute DeBakey type I aortic dissection (ADIAD) is common but has unclear pathogeneses and limited treatments. Receptor-interacting protein kinase 3 (RIP3), a mediator of necroptosis, is associated with human sepsis-induced and posttraumatic AKI, but its role in human postoperative AKI in ADIAD remains unclear. We assumed that RIP3 levels is associated with postoperative AKI in ADIAD.

Methods

Plasma samples and the clinical data of continuous patients with ADIAD were collected prospectively. The patients were divided into three groups according to AKI stage postoperatively. The plasma RIP3 levels were compared among the groups, and the relationship between RIP3 and serum creatinine (sCr), inflammatory cytokines as well as clinical results were analyzed.

Results

Eighty patients were enrolled. The postoperative and elevated RIP3 levels among the three groups were significantly different (P < 0.0001), both with a positive trend across the AKI stage (P for trend < 0.001), and they were also independent risk factors for postoperative AKI in ADIAD (OR = 1.018 and 1.026, P < 0.05). The postoperative RIP3 levels were positively correlated with the aortic crossclamp time (R = 0.253, P < 0.05); the peak values of sCr, procalcitonin, interleukin-6 and lactate postoperatively; the mechanical ventilation time; and the ICU stay time (R = 0.66, 0.369, 0.409, 0.397, 0.474 and 0.435, respectively; all P < 0.001). Plasma RIP3 level and sCr were comparable in diagnosing postoperative AKI in ADIAD (P = 0.898), and higher postoperative RIP3 level was associated with lower survival rate.

Conclusion

The plasma RIP3 levels are associated with postoperative AKI, inflammatory response and clinical outcomes in ADIAD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13019-022-01783-0.

Prediction of Acute Kidney Injury by Cystatin C and [TIMP-2]*[IGFBP7] after Thoracic Aortic Surgery with Moderate Hypothermic Circulatory Arrest

(1) Background: Acute kidney injury (AKI) is a common complication following thoracic aortic surgery (TAS), with moderate hypothermic circulatory arrest (MHCA). However, prediction of AKI with classical tools remains uncertain. Therefore, it was the aim of the present study to evaluate the role of new biomarkers in patients after MHCA. (2) Methods: 101 consecutive patients were prospectively enrolled. Measurements of urinary [TIMP-2]*[IGFBP7] and Cystatin C in the blood were performed perioperatively. Primary endpoint was the occurrence of AKI stage 2 or 3 (KDIGO-classification) within 48 h after surgery (AKI group). (3) Results: Mean age of patients was 69.1 ± 10.9 years, 35 patients were female (34%), and 13 patients (13%) met the primary endpoint. Patients in the AKI group had a prolonged ICU-stay (6.9 ± 7.4 days vs. 2.5 ± 3.1 days, p < 0.001) as well as a higher 30-day-mortality (9/28 vs. 1/74, p < 0.001). Preoperative serum creatinine (169.73 ± 148.97 μmol/L vs. 89.74 ± 30.04 μmol/L, p = 0.027) as well as Cystatin C (2.41 ± 1.54 mg/L vs. 1.13 ± 0.35 mg/L, p = 0.029) were higher in these patients. [TIMP-2]*[IGFBP7] increased significantly four hours after surgery (0.6 ± 0.69 mg/L vs. 0.37 ± 0.56 mg/L, p = 0.03) in the AKI group. Preoperative Cystatin C (AUC 0.828, p < 0.001) and serum creatinine (AUC 0.686, p = 0.002) as well as [TIMP-2]*[IGFBP7] 4 h after surgery (AUC 0.724, p = 0.020) were able to predict postoperative AKI. The predictive capacity of Cystatin C was superior to serum creatinine (p = 0.0211) (4) Conclusion: Cystatin C represents a very sensitive and specific biomarker to predict AKI in patients undergoing thoracic surgery with MHCA even before surgery, whereas the predictive capacity of [TIMP-2]*[IGFBP7] is only moderate and inferior to that of serum creatinine.

En Bloc Arch Reconstruction With the Frozen Elephant Trunk Technique for Acute Type a Aortic Dissection

Objective: The study objective was to evaluate the effect of en bloc arch reconstruction with frozen elephant trunk (FET) technique for acute type A aortic dissection.

Methods: 41 patients with acute Stanford type A dissection underwent en bloc arch reconstruction combined with FET implantation between April 2018 and August 2020. The mean age of the patients was 46 ± 13 years, and 9 patients were female. One patient had Marfan syndrome. Six patients had pericardial tamponade, 9 had pleural effusion, 5 had transient cerebral ischemic attack, and 3 had chronic kidney disease.

Results: The hospital mortality rate was 9.8% (4 patients). 2 (4.9%) patients had stroke, 23 (56.1%) had acute kidney injury, and 5 (12.2%) had renal failure requiring hemodialysis. During follow-up, the rate of complete false lumen thrombosis was 91.6% (33/36) around the FET, 69.4% (25/36) at the diaphragmatic level, and 27.8% (10/36) at the superior mesenteric artery level. The true lumen diameter at the same three levels of the descending aorta increased significantly while the false lumen diameter reduced at the two levels: pulmonary bifurcation and the diaphragm. The 1-, 2-and 3-year actuarial survival rates were 90.2% [95% confidence interval (CI), 81.2–99.2], 84.2% (95% CI, 70.1–98.3) and 70.2% (95% CI, 42.2–98), respectively.

Conclusions: In patients with acute type A dissection, en bloc arch reconstruction with FET technique appeared to be feasible and effective with early clinical follow-up results. Future studies including a large sample size and long-term follow-up are required to evaluate the efficacy.

The Predictive Role of Lymphocyte-to-Monocyte Ratio in Acute Kidney Injury in Acute Debakey Type I Aortic Dissection

Background: The post-operative acute kidney injury (AKI) represents a common complication in the Acute Debakey Type I Aortic Dissection (ADTIAD) and predicts a poorer prognosis. The clinical evidence is scarce supporting the predictive value of the pre-operative lymphocyte-to-monocyte ratio (LMR) in post-operative AKI in ADTIAD.

Methods: In this retrospective cohort study, 190 consecutive patients with ADTIAD enrolled for surgical treatment between January 1, 2013, and December 31, 2018. The diagnosis of AKI followed the Kidney Disease: Improving Global Outcomes guidelines (KDIGO). Pre-operative LMR and other possible risk factors were analyzed for their prognostic value in the post-operative AKI in ADTIAD.

Results: The subjects were assigned to the low-LMR and high-LMR groups according to the median value of pre-operative LMR. For post-operative AKI, the incidence and the severity in the low-LMR group were statistically different from that of the high-LMR group. Besides, the lower LMR was statistically associated with the more extended ICU stay and intubation time and higher incidences of ischemic stroke and in-hospital mortality. Additionally, in the multivariable analysis, the pre-operative LMR was an independent predictor for post-operative AKI in ADTIAD. A predictive model for post-operative AKI in ADTIAD was established incorporating LMR.

Conclusions: LMR is an independent prognostic indicator incorporated into the predictive model with other risk factors to predict the post-operative AKI in ADTIAD.

Development of a practical prediction score for acute renal injury after surgery for Stanford type A aortic dissection

OBJECTIVES

Acute kidney injury (AKI) is a common complication of cardiovascular surgery that is associated with increased mortality, especially after surgeries involving the aorta. Early detection and prevention of AKI in patients with aortic dissection may help improve outcomes. The objective of this study was to develop a practical prediction score for AKI after surgery for Stanford type A acute aortic dissection (TAAAD).

METHODS

This was a retrospective cohort study that included 2 independent hospitals. A larger cohort of 326 patients from The Second Hospital of Jilin University was used to identify the risk factors for AKI and to develop a risk score. The derived risk score was externally validated in a separate cohort of 102 patients from the other hospital.

RESULTS

The scoring system included the following variables: (i) age >45 years; (ii) body mass index >25 kg/m2; (iii) white blood cell count >13.5 × 109/l; and (iv) lowest perioperative haemoglobin <100 g/l, cardiopulmonary bypass duration >150 min and renal malperfusion. On receiver operating characteristic curve analysis, the score predicted AKI with fair accuracy in both the derivation [area under the curve 0.778, 95% confidence interval (CI) 0.726-0.83] and the validation (area under the curve 0.747, 95% CI 0.657-0.838) cohorts.

CONCLUSIONS

We developed a convenient scoring system to identify patients at high risk of developing AKI after surgery for TAAAD. This scoring system may help identify patients who require more intensive postoperative management and facilitate appropriate interventions to prevent AKI and improve patient outcomes.

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.

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.

Cardiopulmonary bypass time is an independent risk factor for acute kidney injury in emergent thoracic aortic surgery: a retrospective cohort study

BACKGROUND

Thoracic aortic surgery and cardiopulmonary bypass are both associated with development of postoperative acute kidney injury. In this study, we undertook to investigate the relationship between cardiopulmonary bypass time and postoperative acute kidney injury in patients undergoing thoracic aortic surgery for acute DeBakey Type I aortic dissection.

METHODS

All patients receiving thoracic aortic surgery for acute DeBakey Type I aortic dissection in Beijing Anzhen hospital from December 2015 to April 2017 were included. Cardiopulmonary bypass time was recorded during surgery. Acute kidney injury was defined based on the Kidney Disease Improving Global Outcomes criteria. A total of 115 consecutive patients were eventually analyzed.

RESULTS

The overall incidence of acute kidney injury was 53.0% (n = 61). The average age was 47.8 ± 10.7 years; 74.8% were male. Mean cardiopulmonary bypass time was 211 ± 56 min. In-hospital mortality was 7.8%. Multivariate logistic regression revealed that cardiopulmonary bypass time was independently associated with the occurrence of postoperative acute kidney injury after adjust confounding factors (odds ratio = 1.171; 95% confidence interval: 1.002-1.368; P = 0.047).

CONCLUSIONS

Cardiopulmonary bypass time is independently associated with an increased hazard of acute kidney injury after thoracic aortic surgery for acute DeBakey Type I aortic dissection. Further understanding of the mechanism of this association is crucial to the design of preventative strategies.

Wider intraoperative glycemic fluctuation increases risk of acute kidney injury after pediatric cardiac surgery

OBJECTIVE

The association between poor intraoperative glycemic control and postoperative acute kidney injury (AKI) in adult cardiac surgery has been observed, but data in the pediatrics remain unknown. We performed a hypothesis that intraoperative hyperglycemia and/or wider glycemic fluctuation were associated with the incidence of postoperative AKI in pediatric cardiac surgery.

METHODS

A retrospective study was performed in pediatrics who underwent cardiac surgery from 2013 to 2016. Perioperative glycemic data up to 48 hours after surgery were collected and analyzed. Patients with AKI were matched 1:1 with patients without AKI by a propensity score. Variables of demographic data, preoperative renal function and glycemic level, perioperative cardiac condition were matched.

RESULTS

The incidence of AKI was 11.5% (118/1026), with 53.4% (63/118), 30.5% (36/118), and 16.1% (19/118) categorized as AKIN stages I, II, and III, respectively. Children who experienced AKI were younger and cyanotic, underwent more complex surgeries, had higher peak intraoperative glucose levels, wider intraoperative glycemic fluctuation, greater inotropic scores and more transfusions, and poor outcomes (all p < .05). After matching, the AKI group had significantly wider intraoperative glycemic fluctuation (p < .05). Logistic regression showed intraoperative glycemic fluctuation was one of the risk factors for AKI (p = .033) and degree of AKI severity stage increased when the glycemic fluctuation increased (p < .01).

CONCLUSIONS

Wider intraoperative glycemic fluctuation, but not hyperglycemia, was associated with an increased incidence of postoperative AKI after pediatric cardiac surgery.

Blood cytokine expression correlates with early multi-organ damage in a mouse model of moderate hypothermia with circulatory arrest using cardiopulmonary bypass

Cardiopulmonary bypass (CPB) with moderate hypothermic cardiac arrest (MHCA) is essential for prolonged complex procedures in cardiac surgery and is associated with postoperative complications. Although cytokine release provoked through MHCA under CPB plays a pivotal role in postoperative organ damage, the pathomechanisms are unclear. Here, we investigated the cytokine release pattern and histological organ damage after MHCA using a recently described mouse CPB model. Eight BALB/c mice underwent 60 minutes of circulatory arrest under CPB, were successively rewarmed and reperfused. Blood cytokine concentrations and liver and kidney function parameters were measured and histological changes to these organs were compared to control animals. Our results showed a marked increase in proinflammatory cytokines and histological changes in the kidney, lung, and liver after CPB. Furthermore, clinical chemistry showed signs of hemolysis and acute kidney injury. These results suggest early onset of solid organ injury which correlates with increased leukocyte infiltration. A better understanding of the interplay between pro-inflammatory cytokine activation and solid organ injury in this model of CBP with MHCA will inform strategies to reduce organ damage during cardiac surgeries in the clinic.

Acute kidney injury in major abdominal surgery: incidence, risk factors, pathogenesis and outcomes

Acute kidney injury (AKI) is a common complication in patients undergoing major abdominal surgery. Various recent studies using modern standardized classifications for AKI reported a variable incidence of AKI after major abdominal surgery ranging from 3 to 35%. Several patient-related, procedure-related factors and postoperative complications were identified as risk factors for AKI in this setting. AKI following major abdominal surgery has been shown to be associated with poor short- and long-term outcomes. Herein, we provide a contemporary and critical review of AKI after major abdominal surgery focusing on its incidence, risk factors, pathogeny and outcomes.

Risk factors for acute kidney injury in overweight patients with acute type A aortic dissection: a retrospective study

BACKGROUND

To identify risk factors for acute kidney injury (AKI) in overweight patients who underwent surgery for acute type A aortic dissection (TAAD).

METHODS

A retrospective study including 108 consecutive overweight patients [body mass index (BMI) ≥24] between December 2009 and April 2013 in Beijing Anzhen Hospital has been performed. AKI was defined by Acute Kidney Injury Network (AKIN) criteria, which is based on serum creatinine (sCr) or urine output.

RESULTS

The mean age of the patients was 43.69±9.66 years. Seventy-two patients (66.7%) developed AKI during the postoperative period. A logistic regression analysis was performed to identify two independent risk factors for AKI: elevated preoperative sCr level and 72-h drainage volume. Renal replacement therapy (RRT) was required in 15 patients (13.9%). The overall postoperative mortality rate was 7.4%, 8.3% in AKI group and 5.6% in non-AKI group. There is no statistically significant difference between the two groups (P=0.32).

CONCLUSIONS

A higher incidence of AKI (66.7%) in overweight patients with acute TAAD was confirmed. The logistic regression model identified elevated preoperative sCr level and 72-h drainage volume as independent risk factors for AKI in overweight patients. We should pay more attention to prevent AKI in overweight patients with TAAD.

Prognostic Implications of Acute Renal Failure after Surgery for Type A Acute Aortic Dissection

BACKGROUND

"Type A" acute aortic dissection (AAAD) is the most challenging among the emergency operations in cardiac surgery. The aim of this study was the evaluation of the role of acute renal failure (ARF) in postoperative survival of patients operated for AAAD.

METHODS

From February 2010 to April 2012, 37 consecutive patients were operated at our department for AAAD. We studied our population by subdividing the patients within groups according to the presence of ARF requiring continuous veno-venous hemofiltration (CVVH) and according to hypothermic circulatory arrest (HCA) times and degrees.

RESULTS

The overall 30-day mortality was 27% (50% group A with ARF, 13% group B no ARF). Acute renal failure requiring CVVH was 37.8%. Multivariate analysis revealed a significant association with 30-day mortality (odds ratio 6.6 and p = 0.020). Preoperative oliguria [urine output less than 30 ml/h (odds ratio 4.7 p = 0.039)], CPB greater than 180 minutes (odds ratio 6.5 p = 0.023) and postoperative bleeding requiring a surgical reopening (odds ratio 12.2 and p = 0.021) were the variables significantly associated with acute kidney injury.

CONCLUSIONS

The data obtained from our analysis bring out the high incidence of renal injuries after surgery for AAAD, and indicate a negative impact on renal injuries of a preoperative oliguria, longer Cardiopulmonary bypass (CBP)/HCA times, and postoperative bleeding requiring a surgical revision. Our data also suggest a better 30-day survival and better renal outcomes in case of shorter HCA and lesser degree of hypothermia. The option of lesser and shorter hypothermia may be very useful, especially for the elderly patients and octogenarians.

Carperitide Increases the Need for Renal Replacement Therapy After Cardiovascular Surgery

OBJECTIVES

Acute kidney injury is a common complication after aortic surgery. Carperitide, a human atrial natriuretic peptide, was reported to be effective for preventing acute kidney injury after cardiac surgery. However, most studies were from single centers, and results of meta-analyses are subject to publication bias. The aim of the present study was to investigate whether carperitide preserved renal function in patients undergoing cardiovascular surgery.

DESIGN

Retrospective cohort study.

SETTING

Participating hospitals (N = 281) in a national database from 2010 to 2013.

PARTICIPANTS

Adult patients (N = 47,032) who underwent cardiovascular surgery.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The main intervention variable investigated was the use of carperitide on the day of surgery. Assessed outcomes included receiving renal replacement therapy within 21 days of surgery and in-hospital mortality. Data were available for 47,032 patients, of whom 2,186 (4.6%) received carperitide on the day of surgery. Multivariate logistic regression analysis revealed that carperitide was significantly associated with a greater likelihood of receiving renal replacement therapy within 21 days of surgery, but not with in-hospital mortality.

CONCLUSIONS

In patients undergoing cardiovascular surgery, carperitide significantly increased the odds of receiving renal replacement therapy within 21 days after surgery.

Reduction in the incidence of acute kidney injury after aortic arch surgery with low-dose atrial natriuretic peptide: a randomised controlled trial

BACKGROUND

Acute kidney injury (AKI) after surgery is associated with an increased risk of adverse events and death. Atrial natriuretic peptide (ANP) dilates the preglomerular renal arteries and inhibits the renin-angiotensin axis. A low-dose ANP infusion increases glomerular filtration rate after cardiovascular surgery, but it is not known whether it reduces the incidence of AKI or the mortality rate.

OBJECTIVE

To evaluate whether an intravenous ANP infusion prevents AKI in patients undergoing aortic arch surgery requiring hypothermic circulatory arrest.

DESIGN

A randomised controlled study.

SETTING

Operating room and intensive care unit at Kawasaki Saiwai Hospital, Kanagawa, Japan.

PATIENTS

Forty-two patients with normal preoperative renal function undergoing elective repair of an aortic arch aneurysm.

INTERVENTION

Patients were assigned randomly to receive a fixed dose of ANP (0.0125 μg (-1) kg(-1)  min) or placebo. The infusion was started after induction of anaesthesia and continued for 24  h postoperatively.

MAIN OUTCOME MEASURES

The primary end-point was the incidence of AKI within 48 h after surgery.

RESULTS

AKI developed in 30% of patients who received ANP compared with 73% of patients who received placebo (P = 0.014). Intraoperative urine output was almost 1 l greater in patients who received ANP (1865 ± 1299 versus 991 ± 480  ml in the control group, P = 0.005). However, there were no differences in mean arterial pressure or number of episodes of hypotension between the groups. Length of hospital and intensive care stays were not significantly different, nor was there a difference in 30-day mortality. No patients required haemodialysis or continuous renal replacement therapy.

CONCLUSION

We found that an intravenous infusion of ANP at 0.0125  μg  kg(-1)  min(-1) is an effective intervention for reducing the incidence of postoperative AKI, and appears to afford a degree of renal protection during and after cardiovascular surgery.

TRIAL REGISTRATION

Kawasaki ANP trial, UMIN Clinical Trials Registry ID: UMIN000011650.

Potentially modifiable risk factors for acute kidney injury after surgery on the thoracic aorta: a propensity score matched case-control study

Perioperative risk factors were identified for acute kidney injury (AKI) defined by the RIFLE criteria (RIFLE = risk, injury, failure, loss, end stage) after surgery on the thoracic aorta with cardiopulmonary bypass (CPB) in this case-control study. A retrospective review was completed for 702 patients who underwent surgery on the thoracic aorta with CPB. A total of 183 patients with AKI were matched 1:1 with patients without AKI by a propensity score. Matched variables included age, gender, body-mass index, preoperative creatinine levels, estimated glomerular filtration rate, a history of hypertension, diabetes mellitus, cerebrovascular accident, smoking history, or chronic obstructive pulmonary disease to exclude the influence of patient demographics, preoperative medical status, and baseline renal function. Multivariate logistic regression analysis was used to evaluate for independent risk factors in the matched sample of 366 patients. The incidence of AKI was 28.6% and 5.9% of patients from the entire sample required renal replacement therapy. AKI was associated with a prolonged postoperative hospital stay and a higher one-month and one-year mortality both in the entire and matched sample set. Independent risk factors for AKI were a left ventricular ejection fraction <55%, preoperative hemoglobin level <10 g/dL, albumin <4.0 g/dL, diagnosis of dissection, operation time >7 hours, deep hypothermic circulatory arrest (DHCA) time >30 min, pRBC transfusion >1000 mL, and FFP transfusion >500 mL. Although the incidence of poor glucose control (blood glucose >180 mg/dL) was higher in patients with AKI in matched sample, it was not an independent risk factor.AKI was still associated with a poor clinical outcome in the matched sample. Potentially modifiable risk factors included preoperative anemia and hypoalbuminemia. Efforts to minimize operation time and DHCA time along with transfusion amount may protect patients undergoing aortic surgery against AKI.

The deep hypothermic circulatory arrest causes more kidney malfunctions based on a novel rabbit model

BACKGROUND AND OBJECTIVES

High incidences of acute kidney injury after cardiopulmonary bypass (CPB) were observed in previous reports. However, whether deep hypothermic circulatory arrest (DHCA) leads to more severe kidney injury than CPB without DHCA remains controversial. The aim of the study was to investigate the effects of DHCA on renal function in a novel rabbit model of using closed-thoracic DHCA.

DESIGN AND SETTINGS

Experimental study on New Zealand white rabbits performed in the Department of Cardiac Surgery, the First Affiliated Hospital of China Medical University.

METHODS

Thirty rabbits were randomly divided into 3 groups : the sham-operated group (Group A, N=10), the CPB group (Group B, N=10), and the DHCA group (Group C, N=10). Serum creatinine (Scr), blood urea nitrogen (BUN), serum cystatin C, neutrophil gelatinase-associated lipocalin (NGAL), malondialdehyde (MDA) levels, superoxide dismutase (SOD) activities, histopathologic llesions, and apoptosis were assessed.

RESULTS

Each single rabbit in Groups B and C died during surgery. Animals received DHCA exhibited more severe kidney impairments than those received CPB and those that were sham operated. Scr and BUN concentrations at 24 and 48 hours after surgery; cystatin C and NGAL concentrations at 12, 24, and 48 hours after surgery; MDA levels, histopathological lesions, and apoptosis score of the kidneys were the highest in Group C, followed by Group B, and were the lowest in Group A (all P < .05). The activities of SOD were the lowest in Group C, followed by Group B, and were the highest in Group A (P < .05).

CONCLUSION

Our study established a simple, convenient, economical, and long-term surviving rabbit model for the study of DHCA-induced organic injury. Based on more significant kidney injuries, including elevated levels of serum cystatin C and NGAL at an early time, increased lipid peroxidation, decreased renal antioxidative ability, enhanced histological lesions, and increased tubular epithelial apoptosis from DHCA animals, we concluded that DHCA has more kidney dysfunctions than CPB without DHCA.

Usefulness of stroke volume index obtained with the FloTrac/ Vigileo system for the prediction of acute kidney injury after radical esophagectomy

PURPOSE

To assess the impact of stroke volume index (SVI) at the end of esophagectomy upon postoperative renal function.

METHODS

We reviewed medical records of 128 patients undergoing esophagectomy. Intraoperative hemodynamics were monitored with the FloTrac sensor/Vigileo monitor system in addition to standard monitors. Patients were divided into two groups according to SVI at the end of surgery: the normal SVI group (n = 76), with SVI ≥ 35 ml/m2, and the low SVI group (n = 52), with SVI<35 ml/m2. We compared postoperative renal function, indicated by serum creatinine and estimated glomerular filtration rate, on post-operative days 0 through 3. We also compared numbers of patients who developed postoperative acute kidney injury (AKI).

RESULTS

Although there were no intergroup differences in preoperative renal function or other intraoperative hemodynamic variables, including arterial pressure, central venous pressure, stroke volume variation, a volume of infusion, urine output, and the total intraoperative in-out balance, estimated glomerular filtration rate was significantly lower and serum creatinine was significantly higher in the low SVI group than in the normal SVI group on postoperative days 1 and 2 (P<0.05). In addition, more patients developed postoperative AKI in the low SVI group than in the normal SVI group (12 of 52 vs. 5 of 76, P = 0.015).

CONCLUSIONS

Low SVI at the end of esophagectomy may represent a risk factor for AKI in the early postoperative period. Further studies are required to examine whether maintaining SVI above 35 ml/m2 reduces the incidence of AKI after esophagectomy.

Low levels of urinary liver-type fatty acid-binding protein may indicate a lack of kidney protection during aortic arch surgery requiring hypothermic circulatory arrest

STUDY OBJECTIVE

To examine the change in liver-type fatty acid-binding protein (L-FABP) levels in patients undergoing aortic arch surgery and the correlation between L-FABP and postoperative acute kidney injury.

DESIGN

Prospective observational study.

SETTING

Operating room of a general hospital.

PATIENTS

36 adult patients.

INTERVENTIONS AND MEASUREMENTS

Urine samples were obtained to measure urinary L-FABP at initiation of cardiopulmonary bypass (CPB) and 5 minutes after termination of hypothermic circulatory arrest.

MAIN RESULTS

22 (61.1%) patients developed acute kidney injury within a 48-hour period. L-FABP increases more than a thousand-fold were found. In patients who subsequently developed acute kidney injury, significant increases in L-FABP were noted from 2.9 (3.6) ng/mg of creatinine before CPB to 62.1 (995.6) ng/mg of creatinine 5 minutes after termination of circulatory arrest. Values in patients who did not develop acute kidney injury increased from 1.1 (5.7) ng/mg before CPB to 1133.0 (6358.8) ng/mg of creatinine showing a significant mean difference (P = 0.011). The area under the L-FABP receiver operating characteristic curve at 5 minutes after termination of circulatory arrest was 0.758. A cutoff value of 75.13 ng/mg of creatinine yielded both good sensitivity (1.000) and specificity (0.546) for detecting non-acute kidney injury. Patients who developed acute kidney injury after aortic arch surgery demonstrated lower levels of urinary L-FABP.

CONCLUSIONS

Low levels of urinary L-FABP may indicate kidney injury and lack of renal protection.

Acute kidney injury after major abdominal surgery: a retrospective cohort analysis

Background. We analyzed the incidence, risk factors, and prognosis of acute kidney injury (AKI) in a cohort of patients undergoing major abdominal surgery. Methods. A total of 450 patients were retrospectively studied. AKI was defined by an increase in serum creatinine (SCr) ≥ 0.3 mg/dl or by an increase in SCr ≥ 50% and/or by a decrease in urine output to 0.5 ml/kg/hour for 6 hours, in the first 48 hours after surgery. Logistic regression method was used to determine predictors of AKI and in-hospital mortality. A two-tailed P value <0.05 was considered significant. Results. One hundred one patients (22.4%) had postoperative AKI. Age (adjusted odds ratio (OR) 1.02, 95% confidence interval (CI) 1.01–1.05), nonrenal Revised Cardiac Risk Index score (adjusted OR 1.9, 95% CI 1.3–3.1, P = 0.003), intraoperative erythrocytes transfusions (adjusted OR 2.2, 95% CI 1.4–3.5, P <.0001), and nonrenal Simplified Acute Physiology Score II (adjusted OR 1.03, 95% CI 1.01–1.06, P = 0.0191) were associated with postoperative AKI. AKI was associated with increased in-hospital mortality (20.8% versus 2.3%, P <.0001; unadjusted OR 11.2, 95% CI 4.8–26.2, P <.0001; adjusted OR 3.7, 95% CI 1.2–11.7, P = 0.024). Conclusion. AKI was common in patients undergoing major abdominal surgery and was associated with in-hospital mortality.

Impact of organ failure and major complications on outcome in acute Type A aortic dissection

OBJECTIVES

Organ failure and major complications after operations for acute Type A aortic dissection impair outcomes. The objective was to analyze the prevalence of organ failure and major complications, their interrelationship and predictors, and their impact on early and late survival.

DESIGN

All operative survivors 1990-2009 (n = 335) were retrospectively reviewed. Predictors of organ failure and major complications (bleeding, infection, renal or respiratory failure, neurological dysfunction, and multisystem organ failure) and their influence on in-hospital and long-term mortality were analyzed with multivariable statistical methods.

RESULTS

Major complication(s) occurred in 153 patients (46%), most frequently bleeding and permanent neurological dysfunction (19% each). Increasing organ system failure index increased in-hospital mortality markedly: zero (2.9%), one (14%), two (33%), three or more (43%), p = 0.002. Reoperation for bleeding (odds ratio [95% confidence interval]) 2.6 [1.1-6.3], multisystem organ failure 4.3 [1.4-13], and permanent neurological dysfunction 14 [6.2-32] were related to in-hospital mortality. The latter two and respiratory failure also entailed increased long-term mortality.

CONCLUSIONS

Organ failure and major complications were common and impacted negatively on both in-hospital and long-term survival. Strategies to avoid or treat organ failure and major complications should improve early and late survival after surgery for acute Type A aortic dissection.

Clinical and biochemical outcomes for additive mesenteric and lower body perfusion during hypothermic circulatory arrest for complex total aortic arch replacement surgery

Surgical repair of transverse aortic arch aneurysms frequently employ hypothermia and antegrade cerebral perfusion as protective strategies during circulatory arrest. However, prolonged mesenteric and lower limb ischemia can lead to significant lactic acidosis and end organ dysfunction, which remains a significant cause of post-operative morbidity and mortality. We report our experience with additive warm mesenteric and lower body perfusion (1-3 L/min, 30°C) in addition to continuous cerebral and myocardial perfusion in 5 patients who underwent total aortic arch replacement with trifurcated head vessel re-implantation and distal elephant trunk reconstruction. Concomitant surgical procedures included re-operations (2), aortic root operations (2), coronary artery bypass (2) and descending thoracic aortic replacement (1). Serum lactate levels demonstrated a rapid decline from a peak 9.9±2.6 post circulatory arrest to 3.4±2.0 in the intensive care unit (ICU). The lowest serum bicarbonate levels were 19.3±3.5 mmol/L, intra-operatively, which normalized to 28.4±2.4 mmol/L on return to the ICU. The lowest pH levels were 7.25±0.10, corrected to 7.43±0.04 on return to the ICU. Mean cardiopulmonary bypass and aortic cross-clamp times were 361±104 and 253±85 minutes, respectively. Mean cerebral and lower body circulatory arrest times were 0 (0) and 50±35 minutes, respectively. The mean time required for systemic rewarming was 95±66 minutes. There were no in-hospital mortalities and no patient experienced any neurological, mesenteric, renal or lower limb ischemic complications. Two patients required mechanical ventilation >24 hours, and one patient returned for reoperation for bleeding. Median intensive care unit and total hospital lengths of stay were 5 and 16 days, respectively. Our results suggest early serum lactate clearance, normalization of acidosis, and metabolic recovery when utilizing a simultaneous cerebral perfusion and warm body protection strategy for complex aortic arch surgery. This additive perfusion strategy may attenuate visceral and lower body ischemia that normally develops during periods of deep hypothermic circulatory arrest.

Cardiac catheterization within 1 to 3 days of proximal aortic surgery is not associated with increased postoperative acute kidney injury

OBJECTIVE

Cardiac catheterization shortly before coronary artery bypass grafting or valve surgery has been associated with increased postoperative acute kidney injury. The relationship between catheterization timing and acute kidney injury after proximal aortic surgery remains unknown.

METHODS

Between August 2005 and February 2011, a total of 285 consecutive patients underwent cardiac catheterization before elective proximal aortic surgery with cardiopulmonary bypass at a single institution. The association between timing of catheterization and postoperative acute kidney injury (defined as postoperative increase in serum creatinine ≥ 50% of baseline) was assessed using logistic regression analysis.

RESULTS

Of 285 patients, 152 (53%) underwent catheterization on preoperative days 1 to 3 and 133 (47%) underwent catheterization on preoperative day 4 or before. Acute kidney injury occurred in 88 (31%) patients, 3 (1.1%) requiring dialysis. Acute kidney injury occurred in 37 (24%) patients catheterized on preoperative days 1 to 3, and 51 (38%) patients catheterized on preoperative day 4 or before. Catheterization on preoperative days 1 to 3 was not associated with an increased risk of acute kidney injury relative to catheterization on preoperative day 4 or before (unadjusted odds ratio, 0.52; 95% confidence interval, 0.31-0.86; P = .01; adjusted odds ratio, 0.35; 95% confidence interval, 0.17-0.73; P = .005).

CONCLUSIONS

Cardiac catheterization within 1 to 3 days of elective proximal aortic surgery appears safe and should be considered acceptable practice for patients at low risk of acute kidney injury.