Hepatic hypertrophy and hemodynamics of portal venous flow after percutaneous transhepatic portal 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.

Assessment of Segmentary Hypertrophy of Future Remnant Liver after Liver Venous Deprivation: A Single-Center Study

Background: Liver venous deprivation (LVD) is a recent radiological technique that has shown promising results on Future Remnant Liver (FRL) hypertrophy. The aim of this retrospective study is to compare the segmentary hypertrophy of the FRL after LVD and after portal vein embolization (PVE). Methods: Patients undergoing PVE or LVD between April 2015 and April 2020 were included. The segmentary volumes (seg 4, seg2+3 and seg1) were assessed before and after the radiological procedure. Results: Forty-four patients were included: 26 undergoing PVE, 10 LVD and 8 eLVD. Volume gain of both segment 1 and segments 2+3 was significantly higher after LVD and eLVD than after PVE (segment 1: 27.33 ± 35.37 after PVE vs. 38.73% ± 13.47 after LVD and 79.13% ± 41.23 after eLVD, p = 0.0080; segments 2+3: 40.73% ± 40.53 after PVE vs. 45.02% ± 21.53 after LVD and 85.49% ± 45.51 after eLVD, p = 0.0137), while this was not true for segment 4. FRL hypertrophy was confirmed to be higher after LVD and eLVD than after PVE (33.53% ± 21.22 vs. 68.63% ± 42.03 vs. 28.11% ± 28.33, respectively, p = 0.0280). Conclusions: LVD and eLVD may induce greater hypertrophy of segment 1 and segments 2+3 when compared to PVE.

Four-dimensional Flow MRI Assessment of Portal Hemodynamics and Hepatic Regeneration after Portal Vein Embolization

Background Percutaneous transhepatic portal vein (PV) embolization (PVE) is a standard preoperative procedure for advanced biliary cancer when the future liver remnant (FLR) is insufficient, yet the effect of this procedure on portal hemodynamics is still unclear. Purpose To assess whether four-dimensional (4D) MRI flowmetry can be used to estimate FLR volume and to identify the optimal time for this measurement. Materials and Methods This prospective single-center study enrolled consecutive adult patients with biliary cancer who underwent percutaneous transhepatic PVE for the right liver between June 2020 and November 2022. Portal hemodynamics were assessed using 4D flow MRI before PVE and within 1 day (0-day group) or 3-4 days (3-day group) after PVE. FLR volume was measured using CT before PVE and after PVE but before surgery. Blood flow changes were analyzed with the Wilcoxon signed rank test, and correlations with Spearman rank correlation. Results The 0-day group included 24 participants (median age, 72 years [IQR, 69-77 years]; 17 male participants), and the 3-day group included 13 participants (median age, 71 years [IQR, 68-78 years]; eight male participants). Both groups showed increased left PV (LPV) flow rate after PVE (0-day group: from median 3.72 mL/sec [IQR, 2.83-4.55 mL/sec] to 9.48 mL/sec [IQR, 8.12-10.7 mL/sec], P < .001; 3-day group: from median 3.65 mL/sec [IQR, 2.14-3.79 mL/sec] to 8.16 mL/sec [IQR, 6.82-8.98 mL/sec], P < .001). LPV flow change correlated with FLR volume change relative to the number of days from PVE to presurgery CT only in the 3-day group (ρ = 0.62, P = .02; 0-day group, P = .11). The output of the regression equation for estimating presurgery FLR volume correlated with CT-measured volume (ρ = 0.78; P = .002). Conclusion Four-dimensional flow MRI demonstrated increased blood flow in residual portal branches 3-4 days after PVE, offering insights for estimating presurgery FLR volume. Published under a CC BY 4.0 license. Supplemental material is available for this article. See also the editorial by Roldán-Alzate and Oechtering in this issue.

Influence of shunt occlusion on liver volume and functions in hyperammonemic cirrhosis patients having large porto-systemic shunts: a randomized control trial

BACKGROUND AND AIMS

Spontaneous-portosystemic-shunts (SPSS) in cirrhosis deprive the liver of nutrient-rich portal blood and contribute to recurrent hepatic encephalopathy (HE). We evaluated the effects of shunt occlusion and redirecting portal blood to liver on its volume and functions.

METHODS

Cirrhosis patients presenting with recurrent HE and having SPSS were randomized to receive standard medical treatment (SMT) or shunt occlusion (SO). The later was performed by plug-assisted or balloon-occluded retrograde transvenous obliteration. The primary endpoint was change in liver volume after a minimum follow-up of 3 months. Secondary objectives included clinical course, liver disease severity indices, arterial ammonia levels and bone density.

RESULTS

Of 40 enrolled patients, 4 in SMT and 2 in SO group were lost to follow-up. The SO was complete in 17 and partial in one, achieving non-recurrence of HE in 17 (94.4%). In these patients, the mean liver volume increased (baseline 1040 ± 335 ml to 1132 ± 322 ml, 8.8% increase, p < 0.001) and was observed in 16/18 (88.89%) patients. In the SMT group, the liver volume decreased (baseline 988 ± 270 ml to 904 ± 226 ml, 8.6% reduction, p = 0.009) during the same period. Serum albumin increased in SO group (2.92 ± 0.40 g/dl to 3.30 ± 0.49 g/dl, p = 0.006) but reduced in SMT group (2.89 ± 0.43 g/dl to 2.59 ± 0.65 g/dl, p = 0.047). After SO, the patients showed a reduction in serum-ammonia levels (181.06 ± 86.21 to 107.28 ± 44.53 μ/dl, p = 0.001) and an improvement in MELD-Na and bone density compared to SMT group. There were no major adverse events following shunt occlusion.

CONCLUSION

Occlusion of large SPSS results in improving the volume and synthetic functions of the liver by restoring hepato-petal portal flow besides reducing serum-ammonia level and recurrence of HE.

CLINICALTRIALS

gov number, NCT03293459.

To Systematically Evaluate and Analyze the Efficacy and Safety of Transcatheter Arterial Chemoembolization (TACE) in the Treatment of Primary Liver Cancer

The efficacy and safety of transcatheter arterial chemoembolization (TACE) are systematically evaluated in the treatment of primary liver cancer, which provides a reference for clinical practice and more in-depth research. Cochrane Library, PubMed, EMbase, CBM, CNKI, VIP, and WanFang Data, supplemented by other searches, collected all randomized controlled trials (RCT) comparing TACE combined with TACE alone for HCC. The meta-analysis, after selecting the literature, extracting data, and evaluating the methodological quality of the included studies following the inclusion criteria, was performed using RevMan 5.1 software. There was statistical difference in 3-year survival rate of TACE combined with heat treatment for advanced hepatocellular carcinoma (OR = 1.72,95%CI (1.22,2.41), P=0.002, I2 = 0%, and Z = 3.12), total effective rate (OR = 1.91,95%CI (1.31,2.78), P=0.0008, I2 = 0%, and Z = 3.37), quality-of-life improvement rate (OR = 2.29,95%CI (1.62,3.23), P < 0.00001, I2 = 83%, and Z = 3.37), and complication rate (OR = 2.29,95%CI (1.62,3.23), P < 0.00001, I2 = 83%, and Z = 3.37). Compared with TACE alone, TACE combined with hyperthermia can significantly improve the survival rate and recent efficacy of patients, improve the quality of life, and have a trend to reduce the incidence of toxicity. However, its long-term efficacy and more comprehensive safety need to be verified by more sample and high-quality RCT.

Fully automated whole-liver volume quantification on CT-image data: Comparison with manual volumetry using enhanced and unenhanced images as well as two different radiation dose levels and two reconstruction kernels

OBJECTIVES

To evaluate the accuracy of fully automated liver volume quantification vs. manual quantification using unenhanced as well as enhanced CT-image data as well as two different radiation dose levels and also two image reconstruction kernels.

MATERIAL AND METHODS

The local ethics board gave its approval for retrospective data analysis. Automated liver volume quantification in 300 consecutive livers in 164 male and 103 female oncologic patients (64±12y) performed at our institution (between January 2020 and May 2020) using two different dual-energy helicals: portal-venous phase enhanced, ref. tube current 300mAs (CARE Dose4D) for tube A (100 kV) and ref. 232mAs tube current for tube B (Sn140kV), slice collimation 0.6mm, reconstruction kernel I30f/1, recon. thickness of 0.6mm and 5mm, 80-100 mL iodine contrast agent 350 mg/mL, (flow 2mL/s) and unenhanced ref. tube current 100mAs (CARE Dose4D) for tube A (100 kV) and ref. 77mAs tube current for tube B (Sn140kV), slice collimation 0.6mm (kernel Q40f) were analyzed. The post-processing tool (syngo.CT Liver Analysis) is already FDA-approved. Two resident radiologists with no and 1-year CT-experience performed both the automated measurements independently from each other. Results were compared with those of manual liver volume quantification using the same software which was supervised by a senior radiologist with 30-year CT-experience (ground truth).

RESULTS

In total, a correlation of 98% was obtained for liver volumetry based on enhanced and unenhanced data sets compared to the manual liver quantification. Radiologist #1 and #2 achieved an inter-reader agreement of 99.8% for manual liver segmentation (p<0.0001). Automated liver volumetry resulted in an overestimation (>5% deviation) of 3.7% for unenhanced CT-image data and 4.0% for contrast-enhanced CT-images. Underestimation (<5%) of liver volume was 2.0% for unenhanced CT-image data and 1.3% for enhanced images after automated liver volumetry. Number and distribution of erroneous volume measurements using either thin or thick slice reconstructions was exactly the same, both for the enhanced as well for the unenhanced image data sets (p> 0.05).

CONCLUSION

Results of fully automated liver volume quantification are accurate and comparable with those of manual liver volume quantification and the technique seems to be confident even if unenhanced lower-dose CT image data is used.

Hepatic Resection for Hepatocellular Carcinoma in the Era of Molecular-targeted Agents and Immune Checkpoint Inhibitors in Japan

Hepatic resection or liver transplantation for hepatocellular carcinoma (HCC) represents the only chance for achieving a cure. For the past several decades in Japan, aggressive hepatic resection has been performed for advanced HCC, with consequent good outcomes. According to the 21st Nationwide Follow-Up Survey of Primary Liver Cancer in Japan, 38.3% of patients were treated with hepatic resection or liver transplantation as the initial treatment. The median overall survival of patients who underwent surgery was 57.0 months, and the 5- and 10-year survival rates were 48.4% and 25.2%, respectively. Since 1964, a total of 10,038 liver transplants (595 deceased-donor and 9,443 living-donor transplants) have been performed in Japan. Neoplastic disease, including HCC, was reported to be the third-most common cause of liver transplantation, and the cumulative 1-, 3-, 5-, and 10-year survival rates of living-donor liver transplants for HCC were 85.0%, 76.2%, 70.9%, and 63.1%, respectively. However, molecular-targeted agents, including sorafenib and lenvatinib, have recently been developed. Furthermore, a significantly longer survival with atezolizumab, which is an immune checkpoint inhibitor, plus bevacizumab was observed compared with sorafenib for unresectable HCC patients. Herein, we review the current status of hepatic resection and liver transplantation for HCC in Japan and discuss the role of hepatic resection in the era of molecular-targeted agents and immune checkpoint inhibitors, as well as the need for a definition of borderline resectable-HCC.

Intraoperative Increase of Portal Venous Pressure is an Immediate Predictor of Posthepatectomy Liver Failure After Major Hepatectomy: A Prospective Study

OBJECTIVES

The aim of this study was to assess intraoperative changes of hepatic macrohemodynamics and their association with ascites and posthepatectomy liver failure (PHLF) after major hepatectomy.

SUMMARY OF BACKGROUND DATA

Large-scale ascites and PHLF remain clinical challenges after major hepatectomy. No study has concomitantly evaluated arterial and venous liver macrohemodynamics in patients undergoing liver resection.

METHODS

Portal venous pressure (PVP), portal venous flow (PVF), and hepatic arterial flow (HAF) were measured intraoperatively pre- and postresection in 67 consecutive patients with major hepatectomy (ie, resection of ≥3 liver segments). A group of 30 patients with minor hepatectomy served as controls. Liver macrohemodynamics and their intraoperative changes (ie, Δ) were analyzed as predictive biomarkers of ascites and PHLF using Fisher exact, t test, or Wilcoxon rank sum test for univariate and logistic regression for multivariate analyses.

RESULTS

Major hepatectomy increased PVP by 26.9% (P = 0.001), markedly decreased HAF by 40.7% (P < 0.001), and slightly decreased PVF by 13.4% (P = 0.011). Minor resections had little effects on hepatic macrohemodynamics. There was no significant association of liver macrohemodynamics with ascites. While middle hepatic vein resection caused higher postresection PVP after right hepatectomy (P = 0.04), the Pringle maneuver was associated with a significant PVF (P = 0.03) and HAF reduction (P = 0.03). Uni- and multivariate analysis revealed an intraoperative PVP increase as an independent predictor of PHLF (P = 0.025).

CONCLUSION

Intraoperative PVP kinetics serve as independent predictive biomarker of PHLF after major hepatectomy. These data highlight the importance to assess intraoperative dynamics rather than the pre- and postresection PVP values.

Induction of Contralateral Hepatic Hypertrophy by Unilobar Yttrium-90 Transarterial Radioembolization versus Portal Vein Embolization: An Animal Study

PURPOSE

To compare hepatic hypertrophy in the contralateral lobe achieved by unilobar transarterial radioembolization (TARE) versus portal vein embolization (PVE) in a swine model.

METHODS

After an escalation study to determine the optimum dose to achieve hypertrophy after unilobar TARE in 4 animals, 16 pigs were treated by TARE (yttrium-90 resin microspheres) or PVE (lipiodol/n-butyl cyanoacrylate). Liver volume was calculated based on CT before treatment and during 6 months of follow-up. Independent t-test (P < .05) was used to compare hypertrophy. The relationship between hypertrophy after TARE and absorbed dose was calculated using the Pearson correlation.

RESULTS

At 2 and 4 weeks after treatment, a significantly higher degree of future liver remnant hypertrophy was observed in the PVE group versus the TARE group, with a median volume gain of 31% (interquartile range [IQR]: 16%-66%) for PVE versus 23% (IQR: 6%-36%) for TARE after 2 weeks and 51% (IQR: 47%-69%) for PVE versus 29% (IQR: 20%-50%) for TARE after 4 weeks. After 3 and 6 months, hypertrophy converged without a statistically significant difference, with a volume gain of 103% (IQR: 86%-119%) for PVE versus 82% (IQR: 70%-96%) for TARE after 3 months and 115% (IQR: 70%-46%) for PVE versus 86% (IQR: 58%-111%) for TARE after 6 months. A strong correlation was observed between radiation dose (median 162 Gy, IQR: 139-175) and hypertrophy.

CONCLUSIONS

PVE resulted in rapid hypertrophy within 1 month of the procedure, followed by a plateau, whereas TARE resulted in comparable hypertrophy by 3-6 months. TARE-induced hypertrophy correlated with radiation absorbed dose.

A systematic review of the impact of portal vein pressure changes on clinical outcomes following hepatic resection

BACKGROUND

There are evolving data correlating elevated post-hepatic resection portal vein pressure (PVP) with risk of developing post-resection liver failure (PLF) and other complications. As a consequence, modulation of PVP presents a potential strategy to improve outcomes following liver resection (LR). The primary aim of this study was to review the existing evidence regarding the impact of post-resection PVP on clinical outcomes in patients undergoing a LR.

METHODS

Systematic literature searches of electronic databases in accordance with PRISMA were conducted. Changes in PVP and clinical outcomes following liver resection were defined according to the existing literature.

RESULTS

Ten studies, consisting of 712 patients with a median age 61 (52-68) years, were identified that met the inclusion criteria. Of those, 77% (n = 550) underwent a major LR and 27% (n = 195) of patients had cirrhosis. Following LR, the median (range) PVP increased from 11.4 mmHg (median baseline, range 7.3-16.4) to 15.9 mmHg (7.9-19). The overall median incidence of PLF was 19%. Six of the ten studies found an elevated PVP after LR predicted PLF. One study found elevated PVP after LR predicted mortality after LR.

CONCLUSION

Elevated PVP following hepatic resection was associated with increased rates of PLF. It was not possible to define a specific threshold PVP for predicting PLF. Modulation of PVP therefore presents a potential strategy to mitigate the incidence of LR. Future studies should standardize on reporting liver remnant and haemodynamics to better characterize clinical outcomes following LR.

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.