Hepatic grooves: An observational study at laparoscopic surgery.

Background: In traditional descriptions, the upper surface of the liver is smooth and convex, but deep depressions are variants that are present in 5%-40% of patients. We sought to determine the relationship between surface depressions and the diaphragm.

Aim: To use exploratory laparoscopy to determine the relationship between surface depressions and the diaphragm.

Methods: An observational study was performed in all patients undergoing laparoscopic upper gastro-intestinal operations between January 1, 2023 and January 20, 2024. A thirty-degree laparoscope was used to inspect the liver and diaphragm. When surface depressions were present, we recorded patient demographics, presence of diaphragmatic bands, rib protrusions and/or any other source of compression during inspection.

Results: Of 394 patients, 343 had normal surface anatomy, and 51 (12.9%) had prominent surface depressions on the liver. There was no significant relationship between the presence of surface depressions and gender nor the presence of rib projections. However, there was significant association between the presence of surface depressions and diaphragmatic muscular bands (P < 0.001).

Conclusion: With these data, the diaphragmatic-band theory has gained increased importance over other theories for surface depressions. Further studies are warranted using cross sectional imaging to confirm relationships with intersectional planes as well as beta-catenin assays in the affected liver parenchyma.