Risk factors for mortality after cardiovascular surgery in patients with functional single ventricle and right isomerism

Objectives: Cardiac malformations are a major component of heterotaxy syndrome that results in significant mortality and morbidity, especially in patients with a single ventricle and right isomerism (RI). The goal of this study was to evaluate the mortality after cardiovascular surgery in patients with a functional single ventricle and RI over a long follow-up period (∼40 years) and to determine the predicted risk factors for mortality.

Methods: We performed a retrospective review of the medical records of 129 consecutive patients with functional single ventricle and RI who underwent pulmonary flow control operations at Mt. Fuji Shizuoka Children's Hospital between 1979 and 2020. To evaluate mortality rates, the patients were divided into 2 groups (era 1: 1979-1999 and era 2: 2000-2020) based on the date of the first-stage palliation.

Results: The estimated survival rate at 10 years was 36.4% in era 1 and 57.8% in era 2. The estimated survival rate improved significantly (P = 0.0268) between the 2 eras. The rate of Fontan procedure completion was also significantly better in the current era (P = 0.0392; 22/59 in era 1 and 38/66 in era 2). In the multivariable analysis, the date of the first-stage palliation was the only predictor of mortality.

Conclusions: The mortality rate after cardiovascular surgery in patients with a functional single ventricle and RI has improved over the past 20 years; however, it still remains high. This improvement may be attributed to our current surgical strategy and clinical management; however, further investigations are needed to prove this observation.