440 Abdominal Heterotaxia: A More Nuanced Anatomy

Introduction The cardiac anomalies associated with left and right atrial appendage isomerism (LAAI and RAAI) are systematically described. However, for the associated abdominal abnormalities, only the laterality of the organs, cardinality of the spleen (asplenia or polysplenia) and the presence or absence of intestinal malrotation are noted. This study aimed to describe in greater detail the abdominal anatomy in abdominal heterotaxia. Method A detailed review of the imaging and clinical records of 23 patients (16 LAAI, 7 RAAI) with abdominal heterotaxia in a cardiac database was performed. Results In no patient was a complete description of abdominal anatomy possible, with all patients displaying unique anatomical presentations. There was a significant association between isomerism and splenic cardinality (12/16 LAAI had polysplenia and 6/7 RAAI had asplenia, p = 0.02). Right-sided stomachs were more commonly associated with gastro-oesophageal reflux (p = 0.048). The stomach and pylorus were ipsilateral in 15/20 patients, with marked variation in gastric orientation; these were novel observations. Ladd’s procedures were performed in 15/23 patients but terminology for intestinal malrotation was inconsistently used. Conclusions The heterotaxic anatomy demands better descriptions for scholarly reasons, but these may lead to a better understanding of upper intestinal dysfunction and the subsequent management of these patients.