A predictive scoring system for insufficient liver hypertrophy after preoperative portal vein embolization

Long-term remnant liver volume dynamics after major hepatectomy for perihilar cholangiocarcinoma following portal vein embolization

BACKGROUND

Portal vein embolization (PVE) followed by major hepatectomy is a common treatment strategy for patients with perihilar cholangiocarcinoma (PHCC); however, the long-term dynamics of the liver remnant volume (LRV) remain unclear. Here, we report the dynamics of the LRV in patients who underwent hepatectomy following PVE.

METHODS

A total of 39 patients with PHCC who underwent right hemihepatectomy or left trisectionectomy with extrahepatic bile duct resection between 2004 and 2021 were enrolled in this study [PVE (n = 27) and non-PVE (n = 12]). Long-term remnant liver dynamics were analyzed in propensity score-matched pairs (n = 10/group).

RESULTS

The LRV/future liver remnant volume (FLRV) at 1 week to 1 month after hepatectomy were smaller in the PVE group than in the non-PVE group (1.53 vs. 1.69, p = .044 and 1.52 vs 1.99, p = .003, respectively). In the non-PVE group, the LRV/FLRV ratio plateaued 1-3 months postoperatively, whereas progressive hypertrophy occurred in the PVE group, and the LRV/FLRV ratio became equal in both groups at 1 year after hepatectomy (1.96 vs. 1.97; p = .799). Multivariate analysis revealed that FLRV/total liver volume (TLV) ≤ 0.43 was the only independent predictor of LRV/FLRV ≥1.9 at 1 year after hepatectomy (odds ratio:5.345, 95% confidence interval:1.210-23.615; p = .027).

CONCLUSION

Although the long-term LRV was nearly equal in both groups, short-term LRV hypertrophy was lower in the PVE group than in the non-PVE group.

Multi-organ Radiomics-Based Prediction of Future Remnant Liver Hypertrophy Following Portal Vein Embolization

BACKGROUND

Portal vein embolization (PVE) is used to induce remnant liver hypertrophy prior to major hepatectomy. The purpose of this study was to evaluate the predictive value of baseline computed tomography (CT) data for future remnant liver (FRL) hypertrophy after PVE.

METHODS

In this retrospective study, all consecutive patients undergoing right-sided PVE with or without hepatic vein embolization between 2018 and 2021 were included. CT volumetry was performed before and after PVE to assess standardized FRL volume (sFRLV). Radiomic features were extracted from baseline CT after segmenting liver (without tumor), spleen and bone marrow. For selecting features that allow classification of response (hypertrophy ≥ 1.33), a stepwise dimension reduction was performed. Logistic regression models were fitted and selected features were tested for their predictive value. Decision curve analysis was performed on the test dataset.

RESULTS

A total of 53 patients with liver tumor were included in this study. sFRLV increased significantly after PVE, with a mean hypertrophy of FRL of 1.5 ± 0.3-fold. sFRLV hypertrophy ≥ 1.33 was reached in 35 (66%) patients. Three independent radiomic features, i.e. liver-, spleen- and bone marrow-associated, differentiated well between responders and non-responders. A logistic regression model revealed the highest accuracy (area under the curve 0.875) for the prediction of response, with sensitivity of 1.0 and specificity of 0.5. Decision curve analysis revealed a positive net benefit when applying the model.

CONCLUSIONS

This proof-of-concept study provides first evidence of a potential predictive value of baseline multi-organ radiomics CT data for FRL hypertrophy after PVE.

Risk factors for postoperative pneumonia after hepatectomy with extrahepatic bile duct resection

BACKGROUND

The present study investigated the incidence of postoperative pneumonia (POP) after hepatectomy with extrahepatic bile duct resection (BDR) and elucidated risk factors for POP.

METHODS

A total of 257 patients undergoing hepatectomy with BDR between 2011 and 2019 were retrospectively reviewed to evaluate the incidence of POP, defined by the Clavien-Dindo grade ≥ II. The predictive factors for POP were identified using logistic regression analysis of the pre- and intraoperative evaluable factors.

RESULTS

Postoperative pneumonia developed in 15 patients (5.8%), diagnosed as grade IV or V in five patients. In a multivariate analysis, a vital capacity ratio (%VC) <80% (odds ratio [OR] 7.30, P = .005), age ≥ 74 years old (OR 5.39, P = .026), and future liver volume remnant (FLR) ratio ≤ 40% (OR 4.97, P = .045) were independent risk factors for POP. Among patients with performing spirometry, the incidence of developing POP was 1.0%, 8.8%, and 60% in patients with 0, 1-2, and 3 risk factors, respectively.

CONCLUSIONS

The incidence of POP in patients undergoing hepatectomy with BDR was 5.8%. A %VC <80%, age ≥74 years old, and FLR ratio ≤40% were identified as preoperative predictive factors of developing POP.

Prediction with functional liver volume assessment to achieve the resection limit after portal vein embolization in patients scheduled major hepatectomy

BACKGROUND

Preoperative portal vein embolization (PVE) stimulates liver hypertrophy and improves the safety of major hepatectomy. It is essential to predict the future remnant liver volume (FRLV) and resection limit following PVE. Previously, we reported that evaluating functional FRLV (fFRLV) using EOB-MRI could predict post-hepatectomy liver failure. In this study, we investigated the usefulness of fFRLV in predicting the achieving of adequate resection limit for safe hepatectomy following PVE.

METHODS

We included 55 patients who underwent PVE and were scheduled for major hepatectomy. We calculated the liver-to-muscle ratio in the remnant liver and fFRLV using EOB-MRI. We investigated the pre-PVE variables in determining the nonachievement of the resection limit.

RESULTS

The median observation period between PVE and the first evaluation was 21 days, and the median growth rate of FRLV was 26.4%. In 54.5% of patients, the resection limit of fFRLV (615 mL/m²) was achieved. In logistic regression and receiver-operating characteristic analyses, pre-PVE fFRLV (p < 0.001, area under the curve: 0.852) was the reliable predictor of achieving the resection limit; the cutoff value of pre-PVE fFRLV was 446 mL/m².

CONCLUSION

Pre-PVE fFRLV can be useful in predicting the achievement of adequate resection limit following PVE.

Muscularity Defined by the Combination of Muscle Quantity and Quality is Closely Related to Both Liver Hypertrophy and Postoperative Outcomes Following Portal Vein Embolization in Cancer Patients

BACKGROUND

Portal vein embolization (PVE) is a common procedure for preventing hepatic insufficiency after major hepatectomy. While evaluating the body composition of surgical patients is common, the impact of muscularity defined by both muscle quantity and quality on liver hypertrophy after PVE and associated outcomes after major hepatectomy in patients with hepatobiliary cancer remain unclear.

METHODS

This retrospective review included 126 patients who had undergone hepatobiliary cancer resection after PVE. Muscularity was measured on preoperative computed tomography images by combining the skeletal mass index and intramuscular adipose content. Various factors including the degree of hypertrophy (DH) of the future liver remnant and post-hepatectomy outcomes were compared according to muscularity.

RESULTS

DH did not differ by malignancy type. Patients with high muscularity had better DH after PVE (P = 0.028), and low muscularity was an independent predictor for poor liver hypertrophy after PVE [odds ratio (OR), 3.418; 95% confidence interval (CI), 1.129-10.352; P = 0.030]. In subgroup analyses in which patients were stratified into groups based on primary hepatobiliary tumors and metastases, low muscularity was associated with higher incidence of post-hepatectomy liver failure (PHLF) ≥ grade B (P = 0.018) and was identified as an independent predictor for high-grade PHLF (OR 3.931; 95% CI 1.113-13.885; P = 0.034) among the primary tumor group. In contrast, muscularity did not affect surgical outcomes in patients with metastases.

CONCLUSIONS

Low muscularity leads to poor liver hypertrophy after PVE and is also a predictor of PHLF, particularly in primary hepatobiliary cancer.

Predictive Factors for Hypertrophy of the Future Liver Remnant After Portal Vein Embolization: A Systematic Review

This systematic review was conducted to determine factors that are associated with the degree of hypertrophy of the future liver remnant following portal vein embolization. An extensive search on September 15, 2020, and subsequent literature screening resulted in the inclusion of forty-eight articles with 3368 patients in qualitative analysis, of which 18 studies were included in quantitative synthesis. Meta-analyses based on a limited number of studies showed an increase in hypertrophy response when additional embolization of segment 4 was performed (pooled difference of medians = − 3.47, 95% CI − 5.51 to − 1.43) and the use of N-butyl cyanoacrylate for portal vein embolization induced more hypertrophy than polyvinyl alcohol (pooled standardized mean difference (SMD) = 0.60, 95% CI 0.30 to 0.91). There was no indication of a difference in degree of hypertrophy between patients who received neo-adjuvant chemotherapy and those who did not receive pre-procedural systemic therapy

(pooled SMD = − 0.37, 95% CI − 1.35 to 0.61), or between male and female patients (pooled SMD = 0.19, 95% CI − 0.12 to 0.50).

The study was registered in the International Prospective Register of Systematic Reviews on April 28, 2020 (CRD42020175708).

Differences in the safety line of the future liver remnant plasma clearance rate of indocyanine green necessary to prevent post-hepatectomy liver failure associated with underlying diseases

PURPOSE

To evaluate differences in the safety line of the future liver remnant plasma clearance rate of indocyanine green (RemK) necessary to prevent posthepatectomy liver failure (PHLF) associated with liver tumors and comorbidities.

METHODS

The subjects of this retrospective study were patients who underwent trisectionectomy, hemihepatectomy, or sectionectomy, other than left lateral sectionectomy, between 2011 and 2018, at the Shizuoka Cancer Center. We analyzed the risk factors for PHLF grades B and C and then evaluated the RemK in these groups, according to various risk factors.

RESULTS

A total of 463 patients were selected for the analyses. Among the patients with PHLF grades B and C, those with diabetes mellitus (DM), liver cirrhosis (LC), or hepatocellular carcinoma (HCC) had significantly higher RemK than those without these diseases. Multivariate analysis identified RemK ≤ 0.078, DM, and creatinine clearance rate < 60 mL/min as independent risk factors for PHLF grades B and C.

CONCLUSIONS

Hepatectomy for patients with DM, HCC, or LC requires more functional hepatic reserve than that evaluated by RemK.

Issues to be considered to address the future liver remnant prior to major hepatectomy

An accurate preoperative evaluation of the hepatic function and application of portal vein embolization in selected patients have helped improve the safety of major hepatectomy. In planning major hepatectomy, however, several issues remain to be addressed. The first is which cut-off values for serum total bilirubin level and prothrombin time should be used to define post-hepatectomy liver failure. Other issues include what minimum future liver remnant (FLR) volume is required; whether the total liver volume measured using computed tomography or the standard liver volume calculated based on the body surface area should be used to assess the adequacy of the FLR volume; whether there is a discrepancy between the FLR volume and function during the recovery period after portal vein embolization or hepatectomy; and how best the function of a specific FLR can be assessed. Various studies concerning these issues have been reported with controversial results. We should also be aware that different strategies and management are required for different types of liver damage, such as cirrhosis in hepatocellular carcinoma, cholangitis in biliary tract cancer, and chemotherapy-induced hepatic injury.

Portal Vein Embolization: Radiological Findings Predicting Future Liver Remnant Hypertrophy

OBJECTIVE. The purpose of this article is to evaluate the radiologic findings predicting the future liver remnant hypertrophy ratio after portal vein embolization of the right branch. MATERIALS AND METHODS. The associations between the radiologic findings and the future liver remnant hypertrophy ratio for 79 patients who underwent portal vein embolization of the right branch between July 2007 and April 2017 were retrospectively analyzed. Multiple linear regression was performed to adjust for potential confounders, and the volume ratio of the right lobe anterior segment, number of proximal small branches from the right anterior and posterior portal veins, transient hepatic parenchymal enhancement, portal vein invasion, and variants of main portal vein anatomy were evaluated. The potential confounders were age, ratio of future liver remnant hypertrophy to total liver volume, indocyanine green clearance rate, maximum serum total bilirubin before portal vein embolization, and history of chemotherapy. RESULTS. Statistically significant associations were found between the future liver remnant hypertrophy ratio and the number of proximal small branches from the right anterior and posterior portal veins (p < 0.001), transient hepatic parenchymal enhancement (p < 0.001), portal vein invasion (p = 0.017), and variants of main portal vein anatomy (p = 0.048). The mean future liver remnant hypertrophy rate was 51.0% (n = 16) in patients without the radiologic findings showing statistically significant differences, and 25.8% (n = 63) in patients with at least one significant finding. CONCLUSION. When added to previously reported factors, the radiologic findings identified can help determine the indications for portal vein embolization and novel strategies for major hepatectomy.