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.
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.
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.
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.