## 5 Conclusions  
Elastography and biochemical markers of fibrosis are valuable tools for screening and monitoring liver fibrosis. Using these noninvasive methods, we assessed liver fibrosis in a group of post-Fontan and post-Glenn patients, given the known prevalence of liver fibrosis in this category of patients. We obtained significantly higher liver stiffness valuesin Fontan patients compared to controls, whereas Glenn patients did not have increased stiffness results. TE liver stiffness results were much higher than those determined by SWE in the Fontan group, which may imply that TE results are more altered by congestion. Fibrotest, Actitest and APRI were significantly increased in both post-Fontan and post-Glenn patients, which implies that liver fibrosis is present before and after the Fontan surgery. We found a negative correlation between liver stiffness and the period of time after the Glenn surgery, suggesting that peri-operative insults increase the liver stiffness. The present study is among few to document the liver damage present in a group of Glenn patients; the evaluation of the patients using two elastography methods is also a novelty. Further studies on larger samples are needed in order to identify precise cutoffs for liver fibrosis for both elastography and serum biomarkers in patients with Fontan and Glenn surgeries. Until then, serial monitoring and documenting the changes in serum fibrosis markers and liver stiffness can be very helpful in the management of these patients.  
Conceptualization, R.-C.M., C.O.M. and R.T.; methodology, C.O.M., R.-C.M. and L.E.M.; validation, C.O.M.; formal analysis, R.-G.M.; investigation, R.-C.M., L.E.M. and C.O.M.; resources, R.T. and C.O.M.; data curation, R.-G.M. and R.-C.M.; writing--original draft preparation, R.-C.M., C.O.M. and R.-G.M.; writing--review and editing, C.O.M., R.T. and L.E.M.; supervision, C.O.M. and R.T.; project administration, C.O.M. and R.-C.M.; funding acquisition, R.-C.M. and C.O.M. All authors have read and agreed to the published version of the manuscript.  
The Fibrotest investigations were funded by the PhD Program of the \"[PERSON]\" University of Medicine, Pharmacy, Science and Technology of Targu-Mures, Gheorghe Marinescu Street No 38, 540136 Targu-Mures, Romania; funding number 45/2019 and 9/2021, financing source 13406/12/7 October 2015.  
Our study was approved by the Ethics Committee of the University of Medicine, Pharmacy, Sciences and Technology, Targu Mures (No. 26/17 March 2016), the Ethics Committee of the Emergency County Hospital, Targu Mures (No. 29921/18 December 2015) and the Ethics Committee of the Emergency Institute for Cardiovascular Diseases and Transplantation, Targu Mures (No. 7908/6 November 2018). The study was performed according to the principles of the Helsinki Declaration.  
The study was explained to both children and their parents/caregivers prior to their inclusion. Signed informed consent was obtained from the parent/caregiver for the participation in the study, as well as on behalf of the child.  
The data presented in this study are available on request from the corresponding author.  
The authors thank the doctors from the Pediatric Cardiology clinic for their support.  
The authors declare no conflict of interest.