Impact of Abdominal Surgery on Neonatal Cardiac Surgery Outcomes: Prevalence, Characteristics, and Associated Risks

<b>Background:</b> Neonatal congenital heart surgery (CHS) patients may have coexisting gastrointestinal disorders and/or complications that may require abdominal surgery. We sought to identify the outcomes of these patients. <b>Methods:</b> The Pediatric Health Information System database was queried to identify neonatal CHS patients. Patients undergoing bowel, hepatobiliary, or gastric operations during their neonatal CHS hospitalization were categorized as the abdominal surgery group and compared with nonabdominal surgery neonatal CHS. <b>Results:</b> A total of 12 437 neonatal CHS patients were included, with 389 (3%) undergoing abdominal surgery during the same hospitalization. Within the abdominal surgery group, 78% (303/389) underwent abdominal surgery after, 19% (74/389) before, and 3% (12/389) both before and after neonatal CHS. The abdominal surgery group was more likely to be preterm (21% [82/389] vs 12% [1446/12 048]), have complex lesions (hypoplastic left heart syndrome: 27.3% [106/389] vs 22.9% [2769/12 048]), and were more likely to develop necrotizing enterocolitis (20.5% [80/389] vs 4% [479/12 048]), all <i>P</i> < .05. In-hospital mortality was significantly higher in the abdominal surgery group (22% [87/389] vs 8% [967/12 048], <i>P</i> < .001). After adjusting for confounders, abdominal surgery was associated with more than 3-fold increase in mortality (OR: 3.34, 95% CI: 2.33-4.78). Odds of mortality remained elevated regardless of whether abdominal surgery occurred before or after neonatal CHS (<i>P</i> < .05). Hospitalization costs were more than doubled in the abdominal surgery group ($401 201 vs $182 036, <i>P</i> < .001). Among survivors of neonatal CHS hospitalization, the abdominal surgery group continued to exhibit lower survival rates at one (94% vs 97%) and five years (85% vs 94%), log-rank <i>P</i> < .001. <b>Conclusion:</b> Patients undergoing abdominal operations during their neonatal cardiac surgery hospitalization represent a highly vulnerable cohort and have more than 3-fold higher odds of mortality.