Revisiting the infracardiac bursa using multimodal methods: topographic anatomy for surgery of the esophagogastric junction

<jats:title> <jats:bold>Abstract</jats:bold> </jats:title><jats:p>In embryology, the infracardiac bursa (<jats:styled-content style="fixed-case">ICB</jats:styled-content>) is a well‐known derivative separated from the omental bursa. During surgeries around the esophagogastric junction (<jats:styled-content style="fixed-case">EGJ</jats:styled-content>), surgeons often encounter a closed space considered to be equivalent to the <jats:styled-content style="fixed-case">ICB</jats:styled-content>, but the macroscopic anatomy in adults is hardly known. This study aimed to revisit the <jats:styled-content style="fixed-case">ICB</jats:styled-content> using multimodal methods to show its development from the embryonic to adult stage and clarify its persistence and topographic anatomy. Histological sections of 79 embryos from Carnegie stage (<jats:styled-content style="fixed-case">CS</jats:styled-content>) 16 to 23 and magnetic resonance (<jats:styled-content style="fixed-case">MR</jats:styled-content>) images of 39 fetuses were examined to study the embryological development of the <jats:styled-content style="fixed-case">ICB</jats:styled-content>. Horizontal sections around the <jats:styled-content style="fixed-case">EGJ</jats:styled-content> obtained from three adult cadavers were examined to determine the topographic anatomy and histology of the <jats:styled-content style="fixed-case">ICB</jats:styled-content>. Further, 32 laparoscopic surgical videos before (<jats:italic>n </jats:italic>= 16) and after (<jats:italic>n </jats:italic>= 16) the start of this study were reviewed to confirm its remaining rate and topographic anatomy in surgery. The <jats:styled-content style="fixed-case">ICB</jats:styled-content> was formed in 1 out of 10 <jats:styled-content style="fixed-case">CS</jats:styled-content>17 samples, and in 8 out of 10 <jats:styled-content style="fixed-case">CS</jats:styled-content>18 samples. Further, it was observed in all <jats:styled-content style="fixed-case">CS</jats:styled-content>19–23 except one <jats:styled-content style="fixed-case">CS</jats:styled-content>23 sample and in 25 (64%) out of 39 fetus samples. Three‐dimensional reconstructed <jats:styled-content style="fixed-case">MR</jats:styled-content> images of fetuses revealed that the <jats:styled-content style="fixed-case">ICB</jats:styled-content> was located at the right alongside the esophagus and the cranial side of the diaphragmatic crus. In one adult cadaver, the caudal end of the <jats:styled-content style="fixed-case">ICB</jats:styled-content> arose from the level of the esophageal hiatus and the cranial end reached up to the level of the pericardium. The inner surface cells of the space consisted of the mesothelium. In laparoscopic surgery, the <jats:styled-content style="fixed-case">ICB</jats:styled-content> was identified in only 11 (69%) out of 16 surgeries before. However, subsequently we were able to identify the <jats:styled-content style="fixed-case">ICB</jats:styled-content> reproducibly in 15 (94%) out of 16 surgeries. Thus, the <jats:styled-content style="fixed-case">ICB</jats:styled-content> is the structure commonly remaining in almost all adults as a closed space located at the right alongside the esophagus and the cranial side of the diaphragmatic crus. It may be available as a useful landmark in surgery of the <jats:styled-content style="fixed-case">EGJ</jats:styled-content>.</jats:p>