Acute Kidney Injury and Mid-term Outcomes After Extra-Cardiac Fontan Conversion.
Kunigo T, Oikawa R, Nomura M.Pediatr Cardiol. 2023 Jun 24. doi: 10.1007/s00246-023-03220-y PMID: 37355505
Take home points:
- Preoperative and 1-year postoperative BNP levels could be associated with postoperative AKI and re-admission due to heart failure.
- Early postoperative nitric oxide (NO) inhalation was more frequently in patients with AKI.
- To prevent AKI after TCPC conversion and reduce re-admission due to heart failure, the authors recommend BNP-guided heart failure treatment preoperatively and following BNP level 3 months after the incidence of AKI even if AKI have restored.
Commentary from Dr. Manoj Gupta (New York City, NY, USA), chief section editor of Pediatric & Fetal Cardiology Journal Watch.
Introduction
The first Fontan operation was performed in 1971, and the procedure was later modified several times. Patients suffering from long-term complications after the classic Fontan procedure need total Cavo-pulmonary connection (TCPC) conversion by the extra-cardiac conduit (ECC) method. Postoperative acute kidney injury (AKI) after initial Fontan operation in pediatric patients is common and risk factor for morbidity and mortality. In this study, we investigated the incidence of postoperative AKI and unplanned re-admission rate due to heart failure at 2-year follow-up in patients who had extra-cardiac Fontan conversion.
Medical records between January 2014 and December 2021 were retrospectively reviewed. Patients who had undergone TCPC conversion by the ECC method were enrolled in this study. The indications for TCPC conversion were symptomatic atrial arrhythmia, atrial enlargement, thrombus in the atrium, low cardiac output in a catheter examination, hypoxemia due to baffle leak, heart failure due to failed Fontan, need for other cardiac surgery, and desire to have children. All the patients underwent TCPC conversion by the ECC method.
The primary outcome was unplanned re-admission rate due to heart failure at 2-year follow-up. Re-admission due to heart failure was defined by a cardiologist’s diagnosis and need for treatment by them. The secondary outcomes were the incidence of AKI, variables that could cause postoperative AKI, perioperative course and 1-year outcomes.
Results
A total of 47 patients were converted to TCPC by the ECC method and analyzed in this study. Postoperative AKI occurred in 22 patients (46.8%) and 5 patients with AKI needed renal replacement therapy (RRT) (Fig. 1). All AKI was diagnosed on creatinine criteria within 48 h after surgery. RRT was initiated in 3 cases for anuria and 2 cases for uremia. All patients recovered from AKI and did not even meet the criteria for AKI stage 1 at discharge. No patient had preoperative hemodialysis for chronic renal failure. Although there was no significant difference between the two groups in renal function, preoperative brain natriuretic peptide (BNP) level was significantly higher in patients with AKI than those without AKI. There were 6 patients in AKI group and 3 patients in non-AKI group with preoperative BNP values over 200 (27.3% vs. 12.0%, p=0.27). There was no significant difference between the two groups in intraoperative data; however, early postoperative nitric oxide (NO) inhalation was more frequently in patients with AKI. There were no significant differences between AKI group and non-AKI group in additional procedure including valve surgery, coronary artery bypass grafting, and Maze during TCPC conversion. At 1 year after conversion, serum creatinine level and ventricular end diastolic pressure were significantly higher and BNP level tended to be higher in patients who had AKI than those who did not have AKI.
Discussion
In this study, early postoperative AKI after extra-cardiac Fontan conversion was associated with unplanned re-admission due to heart failure at 2-year follow-up even when renal function returned to baseline. Prevention of AKI could be more important to improve long-term outcomes after TCPC conversion than treatment of AKI.
“KDIGO bundle” consisting of optimization of volume status and hemodynamics, avoidance of nephrotoxic drugs, and preventing hyperglycemia reduced the frequency and severity of AKI after cardiac surgery. Older age, more than 3 prior sternotomies, prior ablation procedure and higher preoperative right atrial pressure were reported as risk factors for moderate-to-severe AKI after Fontan conversion. Sammour et al. reported that higher preoperative serum creatinine levels were associated with postoperative RRT in their case series of 23 patients after Fontan conversion. Patel et al, independent risk factors for AKI≥2 included older age, ≥3 prior sternotomies, greater preoperative right atrial pressure, and prior catheter ablation procedure. Per Niaz et al, Multivariable risk factors for AKI were asplenia, elevated preoperative pulmonary artery pressure, intraoperative arrhythmias, and elevated post-bypass Fontan pressure.
References:
- Acute kidney injury after Fontan completion: Risk factors and outcomes April 2015 Journal of Thoracic and Cardiovascular Surgery 150(1) DOI:10.1016/j.jtcvs.2015.04.011
- Acute Kidney Injury Is Associated With Increased Long-Term Mortality After Cardiothoracic Surgery https://doi.org/10.1161/CIRCULATIONAHA.108.800011 Circulation. 2009;119:2444–2453
- Incidence, Predictors, and Impact of Postoperative Acute Kidney Injury Following Fontan Conversion Surgery in Young Adult Fontan Survivors Sheetal R. Patel, MD, MSCI , John M. Costello, MD, MPH, Adin-Cristian Andrei, PhD, DOI:https://doi.org/10.1053/j.semtcvs.2021.02.027
- Acute Kidney Injury and Renal Replacement Therapy After Fontan Operation, Talha Niaz, MBBS, Elizabeth H. Stephens, MD, PhD, Stephen J. Gleich, MD DOI:https://doi.org/10.1016/j.amjcard.2021.08.056
