Histological Determinants of Gastric Wall Thickness in Obese Japanese Patients

Overview

This study measured histological gastric wall thickness (GWT) in obese Japanese patients undergoing bariatric surgery, revealing regional differences in full-layer and muscle-layer thickness. The antrum exhibited the thickest gastric wall and muscle layer, while the fornix was the thinnest, with consistent muscle layer ratios across regions.

Background

Laparoscopic sleeve gastrectomy (LSG) is the most common bariatric surgery worldwide and has gained insurance coverage in Japan since 2014, increasing its utilization. Optimal stapler selection during LSG depends on accurate knowledge of gastric wall thickness, which has traditionally been measured using devices on fresh specimens but without histological confirmation. This study aimed to histologically measure gastric wall thickness in formalin-fixed specimens and identify factors influencing these measurements in obese Japanese individuals.

Data Highlights

Key Findings

• Histological full-layer thickness (FLT) and muscle-layer thickness (MLT) were highest in the antrum and lowest in the fornix.
• The ratio of muscle layer thickness to full-layer thickness was consistent across all gastric regions.
• Both FLT and MLT decreased progressively from the antrum to the fornix.
• Histological measurements of gastric wall thickness were comparable to previous device-based measurements on fresh specimens.
• No complications such as bleeding, leakage, stenosis, or adhesive ileus were observed using standard purple cartridges with a closed staple height of 1.75 mm.

Clinical Implications

Understanding the regional variation in gastric wall thickness can guide surgeons in selecting appropriate stapler cartridges during LSG to minimize complications. The consistent muscle layer ratio suggests predictable tissue characteristics across gastric regions, supporting standardized surgical approaches. Histological confirmation of thickness provides a more accurate basis for surgical planning than device measurements alone.

Conclusion

Histological analysis confirms that gastric wall thickness varies by region in obese Japanese patients, with the antrum being thickest and the fornix thinnest. These findings support tailored surgical techniques and stapler selection to improve bariatric surgery outcomes.

References

1. Japanese Bariatric Surgery Data and Techniques, 2014-2023
2. ASMBS Outcome Reporting Standards, 2015
3. Previous Device-Based Gastric Wall Thickness Studies, 2017-2022