Observations on two previously unreported anatomical factors relating to the oesophagogastric junction

The oesophagogastric junction (OGJ) is the anatomical zone where the oesophagus ends and the stomach begins. Its competence in preventing gastro-oesophageal reflux has been shown to depend on a number of factors which have been extensively investigated and widely accepted. This study describes two previously unreported features that show anatomical variation around the OGJ: 1) posterior pericardio-oesophageal (PO) attachment, and 2) posterior location of the gastric fundus relative to the intra-abdominal oesophagus. Measurements and observations were made on 60 formalin-embalmed full-body cadaveric donors from 2023–2026. Total pericardial (TP) and PO attachment lengths were measured along a standardised craniocaudal line. The posterior location of the gastric fundus was assessed using a binary scale. Measurements were made by two investigators. Inter-observer agreement was analysed using intraclass correlation coefficients or Cohen’s kappa (κ). The mean age at death of all donors examined was 87.22 ± 8.11 years (range 68–101), with 31 females. For the posterior pericardio-oesophageal attachment study group, TP was measurable in 45 donors with a mean TP of 117.3 ± 10.66 mm. PO attachment was present in 24.4% (n=11/45), with a mean length of 36.12 ± 9.72 mm, and proportional attachment (PO/TP) of 29.81 ± 9.23%. For the gastric fundus study group, posterior location was assessed in 58 donors. Posterior location was present in 53.4% (n=31/58), with high inter-observer agreement in double-rated cases (κ = 0.946). There was no association between presence of PO attachment and posterior fundus location (p = 1.00). This study found that PO attachment was present in 24.4% of the donors investigated, which could be relevant to hiatus hernia pathophysiology. Posterior location of the gastric fundus was observed in just over 50% of donors, and might theoretically affect competence at the OGJ. Further in vivo and in dynamic imaging studies would be required to demonstrate any potential effects on the OGJ.