Quantitative Evaluation of Right Ventricular Workload Based on the Stroke Work Index in Patients after Right Ventricular Outflow Tract Reconstruction.

The evaluation of right ventricular workload is sometimes complicated in patients after right ventricular outflow tract reconstruction (RVOTR) because both stenotic and regurgitation lesions are involved. In this study, we modified the right ventricular stroke work index (RVSWI) and evaluated the relationship between the modified RVSWI (mRVSWI) and patient prognosis after RVOTR.We enrolled 69 patients who underwent RVOTR (the RVOTR group), including those who needed early reoperation (early reoperation subgroup) and those who did not (follow-up subgroup), and 13 age-matched control participants (control group). Based on the catheterization results 1 year after RVOTR, we compared the mRVSWI between these groups. Additionally, we evaluated the influence of the mRVSWI on the reoperation avoidance rate and survival.The mRVSWI in the RVOTR group was significantly greater than that in the control group (17.7 ± 8.6 vs. 11.0 ± 2.7 g·m/m2, p = 0.008). The mRVSWI in the early reoperation subgroup was significantly greater than that in the follow-up subgroup (32.5 ± 11.1 vs. 15.8 ± 6.0 g·m/m2, p < 0.0001). In the follow-up subgroup, patients with an mRVSWI higher than the upper limit of normal (16.4 g·m/m2) had a greater rate of reoperation than did the other patients (p = 0.0013). One patient died suddenly, and her mRVSWI was consistently high throughout her life.We established the mRVSWI as an index that integrates the pressure and volume load on the right ventricle. Our results indicate the utility of the mRVSWI for predicting patient prognosis after RVOTR.

Predictive role of regional thigh tissue oxygen saturation monitoring during cardiopulmonary bypass in lung injury after cardiac surgery.

Acute respiratory distress syndrome (ARDS) is a serious complication following cardiac surgery mainly associated with the use of cardiopulmonary bypass (CPB), which could increase the risk of mortality and morbidity. This study investigated the association of regional oxygen saturation (rSO2) during CPB with postoperative outcomes, including respiratory function. Patients who underwent cardiac surgery with CPB from 2015 to 2019 were included. Near-infrared spectroscopy was used to monitor rSO2 at the forehead, abdomen, and thighs throughout the surgery. Postoperative markers associated with CPB were assessed for correlations with PaO2/FiO2 (P/F) ratios at intensive care unit (ICU) admission. Postoperative lung injury (LI) was defined as moderate or severe ARDS based on the Berlin criteria, and its incidence was 29.9% (20/67). On multiple regression analysis, the following were associated with P/F ratios at ICU admission: vasoactive-inotropic scores at CPB induction (P = 0.03), thigh rSO2 values during CPB (P = 0.04), and body surface area (P < 0.001). A thigh rSO2 of 71% during CPB was significantly predictive of postoperative LI with an area under the curve of 0.71 (P = 0.03), sensitivity of 0.70, and specificity of 0.68. Patients with postoperative LI had longer ventilation time and ICU stays. Thigh rSO2 values during CPB were a potential predictor of postoperative pulmonary outcomes.

Recurrent left ventricular thrombus due to essential thrombocythemia complicated by COVID-19.

Essential thrombocythemia is a risk factor for thrombosis and hemorrhage. During the perioperative period of cardiac surgery, the risk of thrombosis and hemorrhage increases. Coronavirus disease 2019 (COVID-19) is also associated with thrombosis. We present the case of a 69-year-old man with essential thrombocythemia complicated by COVID-19 who developed a left ventricular thrombus. We performed thrombectomy, but the patient developed recurrent left ventricular thrombus 8 days after surgery. Emergency redo thrombectomy was performed followed by aggressive blood-thinning therapy. The postoperative course was complicated by cardiac tamponade requiring surgical drainage 8 days after the second surgery. The patient was discharged home 25 days after the second operation without any complications. Learning objective: Left ventricular thrombus is a rare but fatal complication associated with essential thrombocythemia. COVID-19 has also been reported to cause coagulopathy. This case suggested that after surgery for left ventricular thrombus complicated by multiple risk factors including essential thrombocythemia and COVID-19, aggressive blood-thinning therapy with combination of anticoagulation, antiplatelet, and metabolic antagonist may help prevent recurrent thrombosis.

Initial thickness of the crescent may not be a reliable predictor of complications in type A intramural haematoma.

OBJECTIVES: This study aimed to investigate changes in haematoma thickness during the early period and their association with disease progression in patients who received initial medical treatment for type A intramural haematoma (IMH). METHODS: Medical records and serial computed tomography angiography (CTA) images of patients who did not undergo emergency aortic repair for type A IMH upon presentation were retrospectively reviewed. The haematoma remodelling rate was determined using the following equation: thickness of the haematoma on the first CTA (mm) - thickness of the haematoma on the second CTA (mm)time between the first and second CTAs (h). RESULTS: Among the 40 patients included in this study, 38 were indicated for initial watch-and-wait strategy, whereas 2 were indicated for emergency aortic repair but declined it. During hospitalization, 10 patients developed disease progression, with 2 in-hospital mortality cases. Analysis of the haematoma remodelling rate in 39 patients revealed that such a rate was significantly associated with the reciprocal of the time from onset. Analysis of all 70 CTA examinations performed within 24 h after the onset of IMH showed that haematoma thickness was significantly associated with the logarithm of the time from onset. Initial regression of the haematoma was not necessarily associated with avoidance of disease progression. CONCLUSIONS: In type A IMH, the thickness of the haematoma in the ascending aorta tended to decrease in the very early period; however, prompt regression of the haematoma was not necessarily associated with avoidance of disease progression.

Trajectory of Abdominal Skeletal Muscle Changes During Cardiac Rehabilitation in Patients With Aortic Disease.

OBJECTIVE: This study focused on routine computed tomography imaging for aortic disease management and evaluated the trajectory of skeletal muscle changes through inpatient and outpatient cardiac rehabilitation. DESIGN: Prospective observational study included patients who underwent abdominal computed tomography three times (baseline, postacute care, and follow-up). The area and density of the all-abdominal and erector spine muscles and intramuscular adipose tissue were measured. A generalized linear model with patients as random effects was used to investigate skeletal muscle changes. RESULTS: Thirty-nine patients completed outpatient cardiac rehabilitation, and 60 were incomplete. Skeletal muscle area significantly decreased from baseline to the follow-up period only in the incomplete rehabilitation group. Skeletal muscle density significantly decreased from baseline to postacute care and increased at the follow-up period, but only patients who completed rehabilitation showed recovery up to baseline at the follow-up period. These trajectories were more pronounced in the erector spine muscle. Intramuscular adipose tissue showed a trend of gradual increase, but only the incomplete rehabilitation group showed a significant difference from baseline to the follow-up period. CONCLUSIONS: The density of skeletal muscle may reflect the most common clinical course; skeletal muscle area and intramuscular adipose tissue are unlikely to improve positively, and their maintenance seemed optimal.

Watch-and-wait strategy for selected patients with type A intramural hematoma.

OBJECTIVE: This single-center retrospective study evaluated early and midterm outcomes of 100 consecutive patients with type A intramural hematoma. METHODS: Initial watch-and-wait strategy was indicated if the maximum aortic diameter was < 50 mm, pain score was < 3/10 on the numerical rating scale, and no ulcer-like projection was observed in the ascending aorta. The primary endpoints of this study were all-cause and aorta-related deaths, and the secondary endpoint was aortic events. RESULTS: Initial watch-and-wait strategy was indicated in 52 patients. Emergency aortic repair was indicated in the remaining 48 patients; 2, 31, and 15 patients died before surgery, underwent emergency surgery, and declined emergency surgery, respectively. Among the watch-and-wait group, 11 (21%) patients underwent aortic repair during hospitalization. In-hospital mortality rates, 5-year survival rates, and 5-year freedom from aorta-related death were not significantly different between the initial watch-and-wait strategy and emergency surgery (2% vs. 6%, 92% vs. 82%, and 100% vs. 94%, respectively). In the initial watch-and-wait strategy group, 5-year freedom from aortic events and freedom from aortic events involving the ascending aorta were 60% and 66%, respectively. CONCLUSIONS: The early and midterm outcomes with the initial watch-and-wait strategy in patients with type A intramural hematoma with a maximum aortic diameter of ≤ 50 mm, pain score of ≤ 3/10, and no ulcer-like projection in the ascending aorta were favorable with no aorta-related death.

Successful treatment of fulminant myocarditis due to COVID-19 in a 5-year-old girl.

Reports of acute myocarditis are increasing due to the worldwide spread of coronavirus disease 2019 (COVID-19). We report a case of a 5-year-old girl with fulminant myocarditis caused by COVID-19, who was successfully treated with veno-arterial extracorporeal membrane oxygenation (VA-ECMO). The unvaccinated patient had developed fever 1 week before attending our hospital and was "presumptive positive" for COVID-19 based on the surrounding infectious situation. The fever resolved, but the day before the visit, abdominal pain appeared. The patient visited her previous physician with vomiting as the main complaint. She was transferred to our hospital due to impaired consciousness and bradycardia, with a heart rate of 40 beats/min. Immediately after transfer, she was diagnosed with complete atrioventricular (AV) block and was scheduled to undergo percutaneous pacing lead insertion. However, the patient had ventricular tachycardia, AV block and hypotension intraoperatively and required cardiopulmonary resuscitation. The patient was in an extremely unstable circulatory state, and VA-ECMO was urgently introduced. After multidisciplinary treatment for acute myocarditis, waiting for an improvement in AV block, and recovery of cardiac function, the patient was weaned from VA-ECMO on the eighth day after admission. The patient was discharged with no cardiac or neurologic sequelae. Learning objective: The rapid introduction of veno-arterial extracorporeal membrane oxygenation for fulminant myocarditis caused by coronavirus disease 2019 (COVID-19) in young children is extremely effective. Vaccination may be important for preventing infection with COVID-19 and avoiding severe complications.

Coil-in-Plug Method for Left Subclavian Artery Embolization in Thoracic Endovascular Aortic Repair with Arch Vessel Debranching.

Objectives: Since 2018, we have routinely placed an Amplatzer vascular plug (AVP) in the proximal left subclavian artery (LSCA) to prevent embolic events during thoracic endovascular aortic repair with arch vessel debranching (d-TEVAR). Type II endoleaks of LSCA origin were observed in two patients (20%), and the coil-in-plug (CIP) method, i.e., microcatheter insertion through the plug and addition of coil embolization, which has been used since August 2019, was performed. This study aims to evaluate the effectiveness of the CIP method for LSCA embolization. Methods: A total of 26 patients who underwent d-TEVAR for an aortic arch aneurysm between 2018 and 2022 were retrospectively reviewed. Ten patients who underwent d-TEVAR with a simple AVP placement (the control group) and 16 patients who underwent d-TEVAR with the CIP method (the CIP group) were compared. Results: Two patients had type II endoleaks in the control group, whereas none had them in the CIP group. LSCA length was significantly shorter in patients with endoleaks than in those without endoleaks (24.5 vs. 50.3 mm; p<0.01). No perioperative deaths or cerebral infarctions occurred in either group. Conclusions: AVP placement in the LSCA during d-TEVAR effectively prevented perioperative cerebral infarction. d-TEVAR with CIP was especially useful in patients with a short LSCA.

Thromboxane prostanoid signaling in macrophages attenuates lymphedema and facilitates lymphangiogenesis in mice : TP signaling and lymphangiogenesis.

BACKGROUND: Accumulating evidence suggests that prostaglandin E2, an arachidonic acid (AA) metabolite, enhances lymphangiogenesis in response to inflammation. However, thromboxane A2 (TXA2), another AA metabolite, is not well known. Thus, this study aimed to determine the role of thromboxane prostanoid (TP) signaling in lymphangiogenesis in secondary lymphedema. METHODS AND RESULTS: Lymphedema was induced by the ablation of lymphatic vessels in mouse tails. Compared with wild-type mice, tail lymphedema in Tp-deficient mice was enhanced, which was associated with suppressed lymphangiogenesis as indicated by decreased lymphatic vessel area and pro-lymphangiogenesis-stimulating factors. Numerous macrophages were found in the tail tissues of Tp-deficient mice. Furthermore, the deletion of TP in macrophages increased tail edema and decreased lymphangiogenesis and pro-lymphangiogenic cytokines, which was accompanied by increased numbers of macrophages and gene expression related to a pro-inflammatory macrophage phenotype in tail tissues. In vivo microscopic studies revealed fluorescent dye leakage in the lymphatic vessels in the wounded tissues. CONCLUSIONS: The results suggest that TP signaling in macrophages promotes lymphangiogenesis and prevents tail lymphedema. TP signaling may be a therapeutic target for improving lymphedema-related symptoms by enhancing lymphangiogenesis.

Trends and Outcomes of Early Rehabilitation in the Intensive Care Unit for Patients With Cardiovascular Disease: A Cohort Study With Propensity Score-Matched Analysis.

BACKGROUND: The effectiveness of acute-phase cardiovascular rehabilitation (CR) in intensive care settings remains unclear in patients with cardiovascular disease (CVD). This study aimed to investigate the trends and outcomes of acute-phase CR in the intensive care unit (ICU) for patients with CVD, including in-hospital and long-term clinical outcomes. METHOD: This retrospective cohort study reviewed a total of 1,948 consecutive patients who were admitted to a tertiary academic ICU for CVD treatment and underwent CR during hospitalisation. The endpoints of this study were the following: in-hospital outcomes: probabilities of walking independence and returning home; and long-term outcomes: clinical events 5 years following hospital discharge, including all-cause readmission or cardiovascular events. It evaluated the associations of CR implementation during ICU treatment (ICU-CR) with in-hospital and long-term outcomes using propensity score-matched analysis. RESULTS: Among the participants, 1,092 received ICU-CR, the rate of which tended to increase with year trend (p for trend <0.001). After propensity score matching, 758 patients were included for analysis (pairs of n=379 ICU-CR and non-ICU-CR). ICU-CR was significantly associated with higher probabilities of walking independence (rate ratio, 2.04; 95% CI 1.77-2.36) and returning home (rate ratio, 1.22; 95% CI 1.05-1.41). These associations were consistently observed in subgroups aged >65 years, after surgery, emergency, and prolonged ICU stay. ICU-CR showed significantly lower incidences of all-cause (HR 0.71; 95% CI 0.56-0.89) and cardiovascular events (HR 0.69; 95% CI 0.50-0.95) than non-ICU-CR. CONCLUSIONS: The implementation of acute-phase CR in ICU increased with year trend, and is considered beneficial to improving in-hospital and long-term outcomes in patients with CVD and various subgroups.

[Mitral Valve Surgery for Active Infective Endocarditis:Techniques to Preserve Native Valve].

OBJECTIVE: In surgery for active infective endocarditis (aIE), it is often difficult to achieve balance between thorough debridement and preservation of native valve. This study aimed to evaluate the validity of our native valve preservation techniques including leaflet peeling and autologous pericardial reconstruction. METHODS: From January 2012 to December 2021, 41 consecutive patients underwent mitral valve surgery for aIE. Twenty-four patients who underwent mitral valve plasty (group P) and 17 patients who underwent mitral valve replacement (group R) were retrospectively compared regarding early and long-term outcomes. RESULTS: Patients in the group P were significantly younger and had fewer preoperative shock, congestive heart failure and cerebral embolism. There was 18% in-hospital mortality in the group R, but none in the group P. In the group P, one patient underwent valve replacement for recurrence of mitral regurgitation 3-years after surgery, and 5-year freedom from mitral reoperation was 93%. CONCLUSIONS: Techniques of leaflet peeling and autologous pericardial reconstruction improved the feasibility of mitral valve plasty for aIE, and the early and long-term outcomes were favorable.

Machine learning predicts blood lactate levels in children after cardiac surgery in paediatric ICU.

BACKGROUND: Although serum lactate levels are widely accepted markers of haemodynamic instability, an alternative method to evaluate haemodynamic stability/instability continuously and non-invasively may assist in improving the standard of patient care. We hypothesise that blood lactate in paediatric ICU patients can be predicted using machine learning applied to arterial waveforms and perioperative characteristics. METHODS: Forty-eight post-operative children, median age 4 months (2.9-11.8 interquartile range), mean baseline heart rate of 131 beats per minute (range 33-197), mean lactate level at admission of 22.3 mg/dL (range 6.3-71.1), were included. Morphological arterial waveform characteristics were acquired and analysed. Predicting lactate levels was accomplished using regression-based supervised learning algorithms, evaluated with hold-out cross-validation, including, basing prediction on the currently acquired physiological measurements along with those acquired at admission, as well as adding the most recent lactate measurement and the time since that measurement as prediction parameters. Algorithms were assessed with mean absolute error, the average of the absolute differences between actual and predicted lactate concentrations. Low values represent superior model performance. RESULTS: The best performing algorithm was the tuned random forest, which yielded a mean absolute error of 3.38 mg/dL when predicting blood lactate with updated ground truth from the most recent blood draw. CONCLUSIONS: The random forest is capable of predicting serum lactate levels by analysing perioperative variables, including the arterial pressure waveform. Thus, machine learning can predict patient blood lactate levels, a proxy for haemodynamic instability, non-invasively, continuously and with accuracy that may demonstrate clinical utility.

Long-term outcomes of hypoplastic left heart syndrome with analysis of the Norwood procedure in infants following bilateral pulmonary artery banding.

Objective: To investigate the early and long-term outcomes of the deferred Norwood procedure by bilateral pulmonary artery banding (BPAB) versus the neonatal Norwood procedure. Methods: This retrospective study examined 46 patients with hypoplastic left heart syndrome and its variants undergoing the Norwood procedure for single ventricle physiology between 2004 and 2022 at 3 institutions. The patients were divided into 2 groups: neonatal Norwood procedure (group N; n = 23) and staged Norwood procedure in infants following BPAB (group I; n = 23). Preoperative risk factors, surgical results, survival rates, Fontan candidacy, and long-term complications were compared. Results: Early survival rates after the Norwood procedure were 91.3% (21 of 23) in both groups. Late survival rates after the Norwood procedure were similar at the 10-year follow-up (group N, 76.3%; group I, 68.7%; P = .63). Fontan completion rates also were comparable in the 2 groups (group N, 77.8%; group I, 85.7%; P = .67). Group N showed a higher median pulmonary artery (PA) index before bidirectional cavopulmonary connection (group N, 177 [interquartile range (IQR), 147-243] mm2/m2; group I, 152 [IQR, 146-163] mm2/m2; P = .03); this trend continued until 5 years after Fontan completion (P = .01). Group N also had a lower rate of freedom from protein-losing enteropathy (PLE) at 9.0 years after the Fontan operation (90.0% vs 52.5% for group I; P = .04), although the incidences of other Fontan-associated events were not significantly different. Conclusions: Fontan candidacy and survival rates were similar regardless of the timing of the Norwood procedure. Early performance of the Norwood procedure may lead to lower rates of late Fontan-associated events, such as PLE.

Hybrid surgery for blunt aortic injury with rupture: a case report.

BACKGROUND: Blunt thoracic aortic injury is one of the most lethal traumatic injuries. Ruptured cases often result in cardiac arrest before arrival at the hospital, and survival is rare. CASE PRESENTATION: A female patient in her 30 s was struck by an automobile while she was walking across an intersection. She was in a state of shock when emergency services arrived and was in cardiac arrest shortly after arriving at the hospital. A left anterolateral thoracotomy revealed a massive hemothorax secondary to thoracic aortic rupture. In addition, the patient had multiple traumas, including maxillary, pelvic, and lumbar burst fractures. We attempted to directly suture the aortic lesion; however, the increasing blood pressure caused the suture to break. We used a thoracic stent graft while ensuring permissive hypotension. Her postoperative prognosis was positive, and she was transferred to another hospital 85 days later. CONCLUSIONS: We successfully performed a hybrid surgery combining thoracotomy and endovascular repair for this emergency case of blunt thoracic aortic injury with rupture.

Rapidly growing thrombus from a ductus arteriosus aneurysm in a neonate.

Ductus arteriosus aneurysm (DAA) is a rare cardiovascular anomaly, and thrombosis of DAA is even less common. The management of asymptomatic DAA with a thrombus is controversial. We here report a neonate with a thrombus from a DAA that grew rapidly into the pulmonary artery. The thrombus was detected incidentally in the main pulmonary artery by routine screening echocardiography. There was no clinical evidence of its presence until a few days after birth. The thrombus grew rapidly, despite administration of heparin. Six days after birth, the patient became cyanotic and had developed right ventricular pressure overload as a result of obstruction of the left pulmonary artery. The thrombus was immediately removed and the DAA resected. The patient was discharged home without any complications. Complications related to thrombus of a DAA can be critical and therefore require careful monitoring. Learning objective: A thrombus extending from a ductus arteriosus aneurysm into the pulmonary artery can have serious consequences; thus, careful monitoring is required. Any signs of such complications should prompt immediate consideration of removal of the aneurysm and thrombus.

Rhythm-control strategy with oral cilostazol for refractory protein-losing enteropathy and sinus node dysfunction after the Fontan operation: A case report.

Despite recent advances in therapeutic approaches, treatment for patients with refractory protein-losing enteropathy (PLE) after undergoing the Fontan procedure remains a challenge for clinicians. In this report, we present a Fontan patient in whom oral cilostazol improved PLE with a restored atrial rhythm. We report on a 13-year-old girl with double-outlet right ventricle, ventricular septal defect, l-transposition of the great arteries, and left ventricle hypoplasia. After the Fontan procedure at 16 months of age, she developed PLE at the age of 2 years. As medical treatments such as diuretics, enalapril, heparin, stent implantation for left pulmonary artery, and oral steroids did not lead to remission, intermittent albumin administration was needed. She had ectopic atrial and junctional rhythms, and cardiac catheterization revealed that the junctional rhythm decreased cardiac output and increased central venous pressure. We therefore started her on cilostazol and succeeded in the maintenance of atrial rhythm, resulting in increased serum albumin, globulin, electrolytes, and nutritional status markers with suppression of bowel inflammation. This patient finally was taken off the steroid and returned to a normal school and home life. Oral cilostazol is a possible therapeutic strategy for refractory PLE, as it improves hemodynamics in Fontan patients with sinus node dysfunction. Learning objective: We present a Fontan patient in whom oral cilostazol for maintaining atrial rhythm improved protein-losing enteropathy (PLE) without any side effects. The junctional rhythm disappeared after the initiation of cilostazol, which suggested that cilostazol stimulated a dominant pacemaker even if the pacemaker was an ectopic focus in the atrium. Oral cilostazol is a possible therapeutic strategy for refractory PLE. We also propose oral cilostazol as a bridging therapy prior to pacemaker implantation.

Acute Kidney Injury after High-Flow Regional Cerebral Perfusion in Neonatal and Infant Aortic Arch Repair.

OBJECTIVES: We applied high-flow regional cerebral perfusion (HFRCP) for aortic arch reconstruction in neonates and infants by monitoring regional oxygen saturation of the thigh (rSO2T) using near-infrared spectroscopy to maintain peripheral perfusion. This study was designed to investigate the optimal perfusion flow of HFRCP for renal protection. METHODS: From 2009 to 2021, 28 consecutive neonates and infants who underwent aortic arch reconstruction with HFRCP were enrolled. The median age of the patients was 27 days; the median body weight was 3.0 kg. In HFRCP, perfusion flow was targeted at approximately 80-100 mL/kg/min and then lowered corresponding to brain rSO2 levels and blood gas data. Isosorbide dinitrate and chlorpromazine were administered to enhance peripheral perfusion flow. Regional oxygen saturation of the forehead and thighs were monitored. The stage of acute kidney injury (AKI) was classified based on the Kidney Disease Improving Global Outcomes criteria. RESULTS: No patients had neurological events and peritoneal dialysis after surgery. The incidence of AKI was 39.3% with only three patients having greater than stage 2 AKI. The maximum postoperative serum creatinine concentration was negatively associated with the lowest rSO2T during HFRCP. The rSO2T during HFRCP was a predictive factor for postoperative creatinine increase of ≧0.3 mg/dL. The area under receiver operating characteristic curve was 0.78 with the cutoff value of 48% for rSO2T. CONCLUSIONS: The rSO2T during HFRCP is a potential predictor of postoperative renal function. To prevent AKI, the rSO2T should be preserved more than 48% by increasing HFRCP flow.

Monitoring of intraoperative femoral oxygenation predicts acute kidney injury after pediatric cardiac surgery.

Cardiopulmonary bypass-associated acute kidney injury (CPB-AKI) is a pediatric cardiac surgery postoperative complication that is associated with a longer duration of mechanical ventilation and length of hospital stay. Identifying an early predictor of CPB-AKI is critical. Near infrared spectroscopy (NIRS), which can provide real-time monitoring of regional tissue oxygen saturation (rSO2) during CPB, may predict CPB-AKI in an early phase of surgical treatment. This study analyzed clinical data from 87 children who underwent an elective surgical repair of ventricular septal defect (VSD) from January 2013 to March 2019. NIRS sensors were placed on the patients' forehead, abdomen, and thighs. The pediatric modified risk, injury, failure, loss, and end-stage (p-RIFLE) score was determined for each patient postoperatively. The incidence of AKI based on the p-RIFLE classification was 11.5% at the end of surgery, 23.0% at 24 h after surgery, and 5.7% at 48 h after surgery. The AKI incidence rate was highest at 24 h after surgery. Multiple regression analysis revealed that femoral oxygenation (rSO2) during CPB, CPB time, oxygen delivery index (DO2i), and lactate at the end of CPB were independent risk factors for AKI. Receiver-operating characteristic curve analysis indicated that femoral oxygenation of 74% or less predicted AKI development within 24 h after surgery. In conclusion, rSO2 measured at the thigh during CPB is highly predictive of CPB-AKI.