Anatomical Size Disparities in Liver Transplantation: Imaging-Derived Abdominal Dimensions and Their Association With Waitlist Outcomes.

BACKGROUND

The objective of this study is to evaluate the association between two imaging-derived measures-anteroposterior diameter (APD) and lateral abdominal wall-IVC distance (L-IVC)-and liver transplant (LT) waitlist outcomes.

METHODS

Retrospective cohort study of 520 adult LT candidates listed at a single academic transplant center from January 1, 2015, to December 31, 2023. APD and L-IVC were measured using cross-sectional abdominal imaging and categorized into three groups using interquartile thresholds: APD (<15.0 cm, 15.0-20.0 cm, >20.0 cm) and L-IVC (<10.0 cm, 10.0-12.5 cm, ≥12.5 cm). The primary outcome was time to LT; the competing outcome was waitlist removal due to death or clinical deterioration. Sub-distribution hazard ratios (SHRs) were estimated using competing risks regression. Harrell's C-statistic and bootstrap comparisons were used to evaluate discrimination versus height, BMI, and body surface area (BSA).

RESULTS

Among 520 candidates (mean [SD] age, 55.7 [10.9] years; 37.5% women), small APD (SHR = 0.51; CI: 0.33-0.72; p = 0.02) and L-IVC (SHR = 0.39; CI: 0.21-0.62: p < 0.001) were associated with lower transplant probability. Candidates with larger APD (>20.0 cm) had the highest risk of waitlist removal (SHR = 1.47; CI:1.02-1.87; p = 0.04). L-IVC was most strongly associated with LT (C-statistic = 0.65) and waitlist removal (C-statistic = 0.67). In sex-stratified models, men with small APD or L-IVC had significantly lower transplant probability, while women with mid-range APD (15.0-20.0 cm) or L-IVC ≥ 12.5 cm had the highest transplant likelihood.

CONCLUSION

Anatomical measurements derived from imaging are more strongly associated with liver transplant waitlist outcomes, outperforming height, BMI, and BSA.