Objective To comprehensively analyze the clinical outcomes of total cavopulmonary connection (TCPC) in the treatment of functional single ventricle combined with heterotaxy syndrome (HS). MethodsA retrospective analysis was conducted on the patients with functional single ventricle and HS who underwent TCPC (a HS group) in Guangdong Provincial People's Hospital between 2004 and 2021. The analysis focused on postoperative complications, long-term survival rates, and identifying factors associated with patient survival. Early and late postoperative outcomes were compared with matched non-HS patients (a non-HS group). Results Before propensity score matching, 55 patients were collected in the HS group, including 42 males and 13 females, with a median age of 6.0 (4.2, 11.8) years and a median weight of 17.0 (14.2, 28.8) kg. Among the patients, there were 53 patients of right atrial isomerism and 2 patients of left atrial isomerism. Eight patients underwent TCPC in one stage. TCPC procedures included extracardiac conduit (n=39), intracardiac-extracardiac conduit (n=14), and direct cavopulmonary connection (n=2). Postoperative complications included infections in 27 patients, liver function damage in 19 patients, and acute kidney injury in 11 patients. There were 5 early deaths. The median follow-up time was 94.7 (64.3, 129.8) months. The 1-year, 5-year, and 10-year survival rates were 87.2%, 85.3%, and 74.3%, respectively. After propensity score matching, there were 45 patients in the HS group and 81 patients in the non-HS group. Compared to the non-HS group, those with HS had longer surgical and mechanical ventilation time, higher infection rates (P<0.05), and a 12.9% lower 10-year survival rate. Multivariate Cox regression analysis identified asplenia was a risk factor for mortality (HR=8.98, 95%CI 1.86-43.34, P=0.006). ConclusionCompared to non-HS patients, patients with HS have lower survival rates after TCPC, and asplenia is an independent risk factor for the survival of these patients.