Abstract 4143791: Second Chances: Outcomes of Left Atrioventricular Valve Re-intervention Following Initial Repair of Atrioventricular Septal Defect

Background: Outcomes after initial atrioventricular septal defect(iAVSD) repair are excellent in the current era. The need for left atrioventricular valve(LAVV) intervention and further reinterventions after iAVSD repair are common and poses significant clinical and surgical challenges. Data on the outcomes after initial LAVV repair remain limited. Research Question / Hypothesis: What is the incidence and outcomes of LAVV reintervention after initial LAAV repair following iAVSD repair? Methods: Retrospective review of the Pediatric Health Information System from 1/2004-12/2023. All patients who underwent AVSD repair were included. LAVV reintervention was defined as LAVV repair or replacement after iAVSD repair. ICD 9/10 codes were used to identify diagnoses and procedures. Results: A total of 7,745 patients underwent AVSD repair. Following iAVSD repair, 503(7%) required LAVV reintervention. Of those, 292(58%) were White Non-Hispanic, 310(62%) female, 255(51%) government insured, and 267(53%) had Down syndrome. Median age was 4.3[2.9-6.7] months at iAVSD repair[cm1] . 405(81%) underwent LAVV repair and 98(20%) replacement. 127(31%) had LAVV repair and 26(27%) had LAVV replacement during the same admission as iAVSD repair. Of the 503, 73(15%) had a second reintervention; 19(26%) had a repeat LAVV repair and 54(74%) LAVV replacement. Freedom from a second reintervention at 15 years was 77%(95%CI:72.1-82.2). Of the 98 patients that underwent initial replacement, older age at initial valve replacement was associated with a decreased risk for second replacement (HR:0.78;95%CI:0.65-0.93,p=0.007). Freedom from re-replacement at 15 years was 44.1%(29.3-67.6) and differed by age at initial replacement.(Figure 1.) Conclusion: LAVV reintervention after iAVSD repair is common and frequently followed by a need for additional LAVV reintervention. Need for early LAVV repair is associated with increased risk of further interventions. These data reinforce the chronic nature of LAVV pathology in AVSD and helps inform counseling for families and patients.