Congenital Heart Surgery

Comparison of management strategies for neonates with symptomatic tetralogy of Fallot and weight <2.5 kg. Qureshi AM, Caldarone CA, Romano JC, Chai PJ, Mascio CE, Glatz AC, Petit CJ, McCracken CE, Kelleman MS, Nicholson GT, Meadows JJ, Zampi JD, Shahanavaz S, Law MA, Batlivala SP, Goldstein BH; Congenital Cardiac Research Collaborative Investigators. J Thorac Cardiovasc Surg. 2022 Jan;163(1):192-207.e3. doi: 10.1016/j.jtcvs.2021.01.100. Epub 2021 Feb 3.PMID: 33726912   Commentary from Dr. Shuhua Luo (Chengdu, Sichuan, China), section editor of Congenital   Take Home Points: In symptomatic neonates with TOF weighing <2.5 kg, mortality and reintervention burden is high independent of treatment strategy. Summary: A total of 120 consecutive neonates with tetralogy of Fallot and symptomatic cyanosis weighing<2.5 kg at initial intervention between 2005 and 2017 were retrospectively reviewed in this study. The patients were categorized into staged repair (SR, n=76) (initial palliation followed by a later complete repair) or primary repair (PR, n=44) groups. In SR group, 53 patients underwent surgical palliation including systemic-pulmonary artery shunt (n=48), and RVOT procedure (n=5), while 23 patients underwent transcatheter palliation including balloon pulmonary valvuloplasty (n=11), PDA stent (n=7), and RVOT stent (n=5). Most patients in the PR group underwent a transannular patch type repair (n=33, 75%), followed by an RVOT conduit (n=11, 25%). No patients in the PR groups received valve-sparing type repair, which was achievable in five patients (7.6%, p=0.062) from the SR group.   The overall observed mortality between the two groups (15.8% vs 18.2%; p=.735) was similar at a median follow-up of 5.3 and 5.5 years, respectively. The result remained the same after propensity score adjustment. As expected, the neonatal (early) morbidity burden was greater in the PR group, however, the cumulative morbidity overall largely favored the PR group. In terms of reintervention, a total of 48 (63.2%) patients in the SR group had reintervention since palliation (both during interstage and post-repair). The most common transcatheter reintervention was pulmonary artery angioplasty and/or stent, and the most common surgical reintervention was RV-PA conduit replacement and S-P shunt revision; A total of 22 (50%) patients in the PR group had reintervention The most common transcatheter reintervention were pulmonary artery (n=10) and RVOT (n=4) angioplasty, and the most common surgical reintervention was RVOT revision or RV-PA conduit replacement. The overall risk of reintervention was comparable between the two groups.   Comment: The authors should be congratulated for provocative analysis of staged- versus primary-repair strategy for the symptomatic TOF babies smaller than 2.5 kg, for whom the controversy is perhaps most pronounced. The most important findings from this study is the operative mortality for these small Fallots remains strikingly high without any decrease in the past 20 years. Indeed, more questions may be raised   1) As the authors note, the major limitation of this study is the heterogeneity of the types of palliation in the SR group. Furthermore, the majority (53/76, 69.7%) of patients underwent surgical SP shunt placement, this may because that the cohort is somewhat historical cohort as the authors include patients from 2005 to 2017. The transcatheter intervention such as ductal stenting and RVOT stenting are recently gaining popular in all these centers. A recent retrospective cohort study including 2,363 neonate TOF patients underwent complete or staged showed complete surgical repair was associated with a significantly higher risk for early and 2-year mortality compared with the staged approach (1). However, the survival between SP shunt and complete repair was similar, therefore the survival benefit of staged approach might be associated with intervention. Unfortunately, the small number of patients in the current cohort preclude any meaningful statistical sub-analysis on the comparison of the outcomes of the surgical vs. interventional palliation.   2) Due to the nature of the retrospective study, several anatomic factors such as the size of the pulmonary annulus, stenosis of the pulmonary valve, tortuosity of the patent ductus arteriosus, length of infundibulum, and degree of infundibular hypertrophy were not included in the analysis, which is important to the selection of management strategies. The author noted the institutional bias being the most important factor associated with the selection of management strategy, however, the anatomic factors might be another potential confounding variable.   3) Another important issue of complete repair, especially in patients smaller than 2.5kg, include exposure of the immature brain to the deleterious effects of cardiopulmonary bypass (low flow or deep hypothermic circulatory arrest). The long-term neurological function might be also important for the clinical decision-making.   In conclusion, the current evidence is from enough for making any recommendation of management selection in such clinical challenging patients. The best to do might be what the individual center is comfortable with. Obviously, a multidisciplinary approach would be necessary including a thorough preoperative discussion including surgeons and interventional cardiologists with understanding the limitations of both the transcatheter and the surgical interventions. The further prospective randomized trial is warranted; however, the trial design is tricky due to limited number of such patients, and significant anatomic variants.   Reference: 1.Savla JJ, Faerber JA, Huang YSV, Zaoutis T, Goldmuntz E, Kawut SM, et al. 2-Year Outcomes After Complete or Staged Procedure for Tetralogy of Fallot in Neonates. J Am Coll Cardiol. 2019 Sep;74(12):1570–9.    

Post-operative Morbidity and Mortality After Fontan Procedure in Patients with Heterotaxy and Other Situs Anomalies. Duong SQ, Zaniletti I, Lopez L, Sutherland SM, Shin AY, Collins RT 2nd. Pediatr Cardiol. 2022 Jun;43(5):952-959. doi: 10.1007/s00246-021-02804-w. Epub 2022 Jan 22.PMID: 35064275   Commentary from Dr. Masamichi Ono (Munich, Germany), section editor of Congenital Heart Surgery Journal Watch   Take Home Points: Using the Pediatric Health Information System database, outcomes after Fontan procedure were compared with and without Heterotaxy syndrome and other situs anomalies (H/SA). As results, patients with heterotaxy syndrome and other situs anomalies had worse outcomes for all study measures: death/transplantation (p=0.047), ECMO (p<0.001), hemodialysis (p=0.026), prolonged mechanical ventilation (p<0.001) and vasoactive medication use and longer LOS (p<0.001). Heterotaxy syndrome and other situs anomalies is associated with increased cardiovascular, renal, and respiratory morbidity, as well as in-hospital mortality after Fontan procedure. Attention to renal and respiratory needs may improve outcomes in this difficult population.   Summary: Using the Pediatric Health Information System (PHIS) data system, this study was designed as a multicenter, retrospective cohort investigation of all patients cared for in the children’s hospitals within the Children’s Hospital Association (CHA) who met study inclusion criteria.   Baseline data were collected from June 2004 to June 2019, and they included 7897 patients at 50 PHIS centers who underwent the Fontan procedure, of whom 1366 (17%) met criteria for heterotaxy syndrome and other situs anomalies (H/SA) and 6531 (83%) met criteria for non-H/SA. H/SA were older (p < 0.001) and less commonly male (p=0.005). Significant race/ethnicity differences (p<0.001) were observed, with H/SA more commonly classified as Asian (p<0.001) or Hispanic (p<0.001). H/SA was associated with all outcomes tested including increased odds of in-hospital mortality/OHT (OR 1.74 [95% CI 1.01–3.03]; p = 0.047), ECMO support (OR 1.74 [95% CI 1.28–2.35]; p<0.001), need hemodialysis (OR 1.66 [95% CI 1.06–2.59]; p=0.026), prolonged mechanical ventilation (OR 1.85 [95% CI 1.53–2.25]; p<0.001), and prolonged vasoactive use (OR 1.65 [95% CI 1.43–10.90]; p<0.001).   In conclusion, the authors demonstrated that patients with H/SA are at increased risk of post-operative morbidity and mortality including in-hospital mortality or OHT, acute kidney injury (AKI) requiring hemodialysis, and prolonged mechanical ventilation and vasoactive use after single ventricle palliation with the Fontan procedure.   Significance: This study leveraged the strength of a large, multicenter US administrative database to provide a more nuanced understanding of outcomes in this difficult and relatively rare subgroup of patients with single ventricle heart disease. The main significance of the study is that, on a multicenter scale and in a relatively similar set of patients and procedures, patients with heterotaxy have increased post-operative respiratory support needs and a higher rate of acute kidney injury requiring dialysis. These findings provide two potentially modifiable targets to decrease the increased mortality observed in this cohort.   Comment: It is well known that patients with Heterotaxy and single ventricle heart disease is a well-described risk factor for poor prognosis. Mortality during first stages of palliation is high, but may improve after the Glenn procedure, with recent survival estimates of 60% at 10 years. This is linked to associated cardiac disorders, such as obstructed pulmonary venous return, atrioventricular valve regurgitation, and anomalous systemic venous return. However, recent Fontan registry reports from Australia and New Zealand have shown equivalent survival of patients with heterotaxy compared to others after hospital discharge.   In this study, post-operative day 0 extubation was strongly associated with non-mortality. They observed that patients with H/SA have lower rates of early (post-operative day 0) extubation and higher rates of prolonged mechanical ventilation. They postulate that intrinsic respiratory compromise related to ciliary dysfunction might contribute to the observed association of H/SA and prolonged respiratory support needs.   In this study, the authors hypothesized that patients with H/SA would have higher rates of AKI requiring hemodialysis, as we had described in this patient group after OHT. Indeed, we observed increased rates of AKI requiring hemodialysis after Fontan surgery in patients with H/SA, though the overall incidence was low. They speculated that heterotaxy is associated with increased rates of genitourinary malformations and an additional mechanism may be related to underlying ciliopathy, which has been associated with renal dysfunction. Both motile and non-motile cilia are important in establishment of left–right differentiation and non-motile ciliopathy is associated with polycystic kidney disease.   The race and gender might be an important factor. They observed a higher proportion of Hispanic and Asian patients, as well as fewer males, in the H/SA group. This is in concordance with birth defect registries that suggest a predominance of females and Hispanic ethnicity. Series from Taiwan, Japan, and Korea have all reported heterotaxy in approximately one-third of patients who underwent Fontan palliation.   We should remain vigilant and attentive to renal and respiratory complications to continue to improve surgical outcomes in patients with heterotaxy syndrome and single ventricle heart disease.