Standardizing Upper Abdominal Fascial Terminology: A Transdisciplinary Expert Consensus From the Japanese Society for Endoscopic Surgery.

BACKGROUND

Terminology describing fascial structures in the upper abdomen remains inconsistent across surgical specialties. Eponymous structures such as the fasciae of Toldt, Gerota, Fredet, and Treitz are widely used, but their definitions vary among disciplines. To address this issue, the Japanese Society for Endoscopic Surgery established a transdisciplinary surgical working group to standardize intraoperative fascial nomenclature in the upper abdomen.

METHODS

A transdisciplinary surgical expert panel comprising surgeons from upper gastrointestinal, colorectal, hepatopancreatobiliary, and urological specialties held structured consensus meetings between February and September 2023. Surgeons from each field presented intraoperative anatomical structures with inconsistent terminology. Through iterative discussions based on intraoperative findings and surgical anatomy, consensus statements were developed.

RESULTS

Four consensus statements were established. First, the renal fascia (Gerota fascia) was recognized as a representative relatively dense condensation fascia that can be consistently identified intraoperatively. Second, structures traditionally referred to as the fasciae of Toldt, Fredet, and Treitz were interpreted as regional or topographic expressions of fusion fascia, rather than independent anatomical membranes. Fusion fascia was understood as a loose, multilayered fusion-related connective tissue zone within the broad operative anatomical spectrum of fascia. Third, because fusion fascia is multilayered, defining a single fixed surgical interface was considered inappropriate. Fourth, membrane-like structures exposed on the visceral side after dissection of the fusion fascia were collectively designated as proper visceral fasciae.

CONCLUSIONS

This surgeon-led consensus provides an operative nomenclature framework for fascial structures recognized intraoperatively in upper abdominal endoscopic surgery. The three core terms may serve as a basic conceptual skeleton for describing upper abdominal fascial anatomy and facilitate cross-specialty communication.