Preoperative Predictors of Insufficient Future Liver Remnant Hypertrophy Following Percutaneous Transhepatic Portal Vein Embolization: A Single-Center Retrospective Cohort Study

Background Percutaneous transhepatic portal vein embolization (PTPE) is a widely used preoperative procedure to augment future liver remnant (FLR) volume before major hepatectomy. However, a subset of patients fails to achieve sufficient FLR hypertrophy following PTPE. Early identification of patients at risk for insufficient hypertrophy would facilitate the timely planning of additional strategies. This study aimed to identify preoperative predictors of insufficient FLR hypertrophy following PTPE, with particular focus on nutritional markers. Methods We retrospectively reviewed 87 patients who underwent PTPE at our institution between April 2010 and February 2026. After excluding 18 patients who underwent left-sided PTPE and eight with confirmed recanalization, 61 patients were included in the final analysis. Insufficient FLR hypertrophy was defined as a hypertrophy ratio (post-PTPE FLR volume/pre-PTPE FLR volume) < 1.3. Univariable and multivariable logistic regression analyses were performed to identify preoperative predictors. Two patients were excluded from the multivariable analysis and subsequent analyses due to missing transthyretin (TTR) values, resulting in an analytical sample of 59 patients for these analyses. Receiver operating characteristic (ROC) curve analysis was performed for independent predictors, and patients were stratified into four risk groups based on the identified cutoff values. Results Insufficient FLR hypertrophy was observed in 24 patients (39.3%). On univariable analysis, pre-PTPE FLR volume (p = 0.001), pre-PTPE FLR ratio (p = 0.005), total liver volume (TLV) (p = 0.022), total bilirubin (TB) (p = 0.046), cholinesterase (CHE) (p = 0.028), TTR (p = 0.047), and HH15 (p = 0.027) were significantly associated with insufficient hypertrophy. Multivariable logistic regression identified pre-PTPE FLR volume (odds ratio (OR) = 4.277, 95% confidence interval (CI): 1.873-9.767; p = 0.001) and TTR (OR = 0.874, 95% CI: 0.770-0.993; p = 0.039) as independent predictors. ROC analysis yielded an area under the curve (AUC) of 0.809 for pre-PTPE FLR volume (optimal cutoff: 428.3 mL), and 0.660 for TTR (optimal cutoff: 14.9 mg/dL); the combined model incorporating both predictors yielded an AUC of 0.847 (95% CI: 0.740-0.936). When patients were stratified by these cutoff values, all patients in the high-risk group (pre-PTPE FLR volume ≥ 428.3 mL and TTR ≤ 14.9 mg/dL; n = 7) experienced insufficient hypertrophy, compared with only 13.3% in the low-risk group (neither risk factor present; n = 30). Conclusions Pre-PTPE FLR volume was identified as the strongest preoperative predictor of insufficient FLR hypertrophy following PTPE, with TTR demonstrating a significant independent association as a complementary predictor. The combination of these two variables, obtainable from routine computed tomography (CT) volumetry and laboratory testing, may inform preoperative risk stratification prior to PTPE, although the cutoff values were derived exploratorily and require external validation in larger, multicenter cohorts.