Natural history of portal vein embolization before liver resection: a 23-year analysis of intention-to-treat results

Image-guided percutaneous strategies to improve the resectability of HCC: Portal vein embolization, liver venous deprivation, or radiation lobectomy?

Despite considerable advances in surgical technique, many patients with hepatic malignancies are not operative candidates due to projected inadequate hepatic function following resection. Consequently, the size of the future liver remnant (FLR) is an essential consideration when predicting a patient's likelihood of liver insufficiency following hepatectomy. Since its initial description 30 years ago, portal vein embolization has become the standard of care for augmenting the size and function of the FLR preoperatively. However, new minimally invasive techniques have been developed to improve surgical candidacy, chief among them liver venous deprivation and radiation lobectomy. The purpose of this review is to discuss the status of preoperative liver augmentation prior to resection of hepatocellular carcinoma with a focus on these three techniques, highlighting the distinctions between them and suggesting directions for future investigation.

Histological and radiological analysis of simultaneous dual hepatic vein embolization for right-sided major hepatectomy

PURPOSE

Simultaneous dual hepatic vein embolization (DHVE) has been proposed for safe right-sided hepatectomy, with good results for liver hypertrophy and function. However, the histological and radiological findings of DHVE have not been thoroughly investigated.

METHODS

This study included 14 patients who underwent DHVE before right-sided major hepatectomy. DHVE was performed if the future liver remnant was < 35% or borderline, but with concomitant vascular resection. The liver function was assessed using the signal intensity on Gd-EOB-DTPA-MRI. A histological evaluation of the area of DHVE and portal vein embolization (PVE) were performed.

RESULTS

The median pre- and post-functional liver remnants were 363 ml and 498 ml, respectively (p < 0.001). The median growth rate was 48.6%, and there was no post-hepatectomy liver failure in the patients who underwent DHVE. The signal intensity ratio in the area of DHVE was lower than that in the areas of PVE and the remnant liver (p < 0.01). The degree of congestion and necrosis was greater in the area of DHVE than in the area of PVE alone (p < 0.01 and p = 0.04, respectively).

CONCLUSIONS

We observed good liver hypertrophy after DHVE and histological and radiological changes in the area of DHVE. Our findings provide a compelling rationale for further investigation of the mechanism of liver hypertrophy in DHVE.

Comparing iodized oil with polyvinyl alcohol for portal vein embolization in promoting liver remnant increase before partial hepatectomy

BACKGROUND

To compare the efficacy and safety of iodized oil versus polyvinyl alcohol (PVA) particles in portal vein embolization (PVE) before partial hepatectomy.

METHODS

From October 2016 to December 2021, 86 patients who planned to undergo hepatectomy after PVE were enrolled, including 61 patients post-PVE with PVA particles + coils and 25 patients post-PVE with iodized oil + coils. All patients underwent CT examination before and 2-3 weeks after PVE to evaluate the future liver remnant (FLR). The intercohort comparison included the degree of liver volume growth, changes in laboratory data, and adverse events.

RESULTS

There was no significant difference in the resection rate between the iodized oil group and the PVA particle group (68 % vs. 70 %, p = 0.822). In terms of the degree of hypertrophy (9.52 % ± 13.47 vs. 4.03 % ± 10.55, p = 0.047) and kinetic growth rate (4.07 % ± 5.4 vs. 1.55 % ± 4.63, p = 0.032), the iodized oil group was superior to the PVA group. The PVE operation time in the PVA particle group was shorter than that in the iodized oil group (121. 72 min ± 34.45 vs. 156. 2 min ± 71.58, p = 0.029). There was no significant difference in the degree of hypertrophy between the high bilirubin group and the control group (5.32 % ± 9.21 vs. 6.1 % ± 14.79, p = 0.764). Only 1 patient had a major complication.

CONCLUSIONS

Compared with PVA particles, iodized oil PVE can significantly increase liver volume and the degree of hypertrophy without any significant difference in safety.

A systematic review and meta-analysis of liver venous deprivation versus portal vein embolization before hepatectomy: future liver volume, postoperative outcomes, and oncological safety

Introduction

This systematic review aimed to compare liver venous deprivation (LVD) with portal vein embolization (PVE) in terms of future liver volume, postoperative outcomes, and oncological safety before major hepatectomy.

Methods

We conducted this systematic review and meta-analysis following the PRISMA guidelines 2020 and AMSTAR 2 guidelines. Comparative articles published before November 2022 were retained.

Results

The literature search identified nine eligible comparative studies. They included 557 patients, 207 in the LVD group and 350 in the PVE group. This systematic review and meta-analysis concluded that LVD was associated with higher future liver remnant (FLR) volume after embolization, percentage of FLR hypertrophy, lower failure of resection due to low FLR, faster kinetic growth, higher day 5 prothrombin time, and higher 3 years' disease-free survival. This study did not find any difference between the LVD and PVE groups in terms of complications related to embolization, FLR percentage of hypertrophy after embolization, failure of resection, 3-month mortality, overall morbidity, major complications, operative time, blood loss, bile leak, ascites, post hepatectomy liver failure, day 5 bilirubin level, hospital stay, and three years' overall survival.

Conclusion

LVD is as feasible and safe as PVE with encouraging results making some selected patients more suitable for surgery, even with a small FLR.

Systematic review registration

The review protocol was registered in PROSPERO before conducting the study (CRD42021287628).

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.

Liver Venous Deprivation Versus Portal Vein Embolization Before Major Hepatectomy for Colorectal Liver Metastases: A Retrospective Comparison of Short- and Medium-Term Outcomes

BACKGROUND

Liver venous deprivation (LVD) is a recent radiological technique performed to induce hypertrophy of the future liver remnant. Medium-term results of major hepatectomy after LVD have never been compared with the actual standard of care, portal vein embolization (PVE).

METHODS

We retrospectively compared data from 33 consecutive patients who had undergone LVD (n = 17) or PVE (n = 16) prior to a right hemi-hepatectomy or right extended hepatectomy indicated for colorectal liver metastases (CRLM) between May 2015 and December 2019.

RESULTS

The 1-year and 3-year overall survival (OS) rates in the LVD group were 81.3% (95% confidence interval [CI]: 72-90) and 54.7% (95% CI: 46-63), respectively, against 85% (95% CI: 69-101) and 77.4% (95% CI: 54-100) in the PVE group; the differences were not statistically significant (p = 0.64). The median disease-free survival (DFS) rate was also comparable: 6 months (95% CI: 4-7) in the LVD group and 12 months (95% CI: 1.5-13) in the PVE group (p = 0.29). The overall intra-operative and post-operative complication rates were similar between the two groups. The mean daily kinetic growth rate (KGR) was found to be higher after LVD than after PVE (0.2% vs. 0.1%, p = 0.05; 10 cc/day vs. 4.8 cc/day, p = 0.03), as was the mean increase in future liver remnant volume (FLR-V) (49% vs. 27%, p = 0.01).

CONCLUSIONS

The LVD technique is well tolerated in patients undergoing right hemi-hepatectomy or right extended hepatectomy for CRLM. When compared with the PVE technique, the LVD technique has similar peri-operative and medium-term outcomes, but higher KGR and FLR-V increase.

A prospective study of sequential hepatic vein embolization after portal vein embolization in patients scheduled for right-sided major hepatectomy: Results of feasibility and surgical strategy using functional liver assessment

BACKGROUND

Hepatic vein embolization (HVE) added to portal vein embolization (PVE) can further increase future remnant liver volume (FRLV) compared with PVE alone. This study was aimed to evaluate feasibility of sequential HVE in a prospective trial and to verify surgical strategy using functional FRLV (fFRLV).

METHODS

Hepatic vein embolization was prospectively indicated for post-PVE patients scheduled for right-sided major hepatectomy if the resection limit of fFRLV using EOB-magnetic resonance imaging was not satisfied. The resection limit was fFRLV: 615 mL/m² for predicting post-hepatectomy liver failure. Patients who underwent sequential PVE-HVE (n = 12) were compared with those who underwent PVE alone (n = 31).

RESULTS

All patients underwent HVE with no severe complications. Median fFRLV increased from 396 (range: 251-581) to 634 (range: 422-740) mL/m² by sequential PVE-HVE. From PVE to HVE, both of FRLV (P < .001) and fFRLV (P = .005) significantly increased. The increased width of fFRLV was larger than that of FRLV after performing HVE. Median growth rate was 71.3 (range: 33.3-80.3) %, which was higher than that of PVE alone (27.0%, range: 6.0-78.0). All-cohort resection rate was 88.3%. Strategy of using fFRLV for the resection limit and performing HVE in patients with insufficient functional volume resulted in no liver failure in all patients who underwent hepatectomy.

CONCLUSIONS

Sequential HVE after PVE is feasible and safe, and HVE induced possibility of further liver growth and its functional improvement. Our surgical strategy using fFRLV may be justified.

Portal vein embolization with absolute ethanol to induce hypertrophy of the future liver remnant

Background

Preoperative portal vein embolization (PVE) is widely used prior to major liver resection to reduce the risk of post-hepatectomy liver failure (PHLF). We evaluated the efficacy and safety of PVE using absolute ethanol.

Methods

Consecutive patients undergoing preoperative PVE between February 2003 and February 2020 at a high-volume tertiary institution were retrospectively reviewed. Hypertrophy of the future liver remnant (FLR) was determined by comparing volumetric data using semi-automated software on computed tomography or magnetic resonance imaging before and after PVE. Efficacy of absolute ethanol was evaluated by the percentage increase in the FLR volume and the ratio of the FLR to the total liver volume (TLV). Technical success and complications following PVE were evaluated. Feasibility of hepatectomy following PVE and the incidence of PHLF were determined.

Results

Sixty-two patients underwent preoperative PVE using absolute ethanol. The technical success rate was 95.2%. Median time interval between PVE and follow-up imaging was 34 days (range 6–144 days). The mean increase in FLR volume and ratio of the FLR to TLV were 43.6 ± 34.4% and 12.3 ± 7.7% respectively. Major adverse events occurred in 3 cases (4.8%) and did not preclude consideration of surgery. Forty-two patients (67.8%) proceeded to surgery for intended hepatectomy of which 36 patients (58.1%) underwent liver resection. Major post-operative complications occurred in 4 patients (11.1%) and there were no cases of PHLF.

Conclusion

Preoperative PVE with absolute ethanol is effective and safe in inducing hypertrophy of the FLR before partial hepatectomy to prevent PHLF.

Portal vein embolization failure: Current strategies and future perspectives to improve liver hypertrophy before major oncological liver resection

Portal vein embolization (PVE) is currently considered the standard of care to improve the volume of an inadequate future remnant liver (FRL) and decrease the risk of post-hepatectomy liver failure (PHLF). PHLF remains a significant limitation in performing major liver surgery and is the main cause of mortality after resection. The degree of hypertrophy obtained after PVE is variable and depends on multiple factors. Up to 20% of patients fail to undergo the planned surgery because of either an inadequate FRL growth or tumor progression after the PVE procedure (usually 6-8 wk are needed before surgery). The management of PVE failure is still debated, with a lack of consensus regarding the best clinical strategy. Different additional techniques have been proposed, such as sequential transarterial chemoembolization followed by PVE, segment 4 PVE, intra-portal administration of stem cells, dietary supplementation, and hepatic vein embolization. The aim of this review is to summarize the up-to-date strategies to overcome such difficult situations and discuss future perspectives on improving FRL hypertrophy.

Portal vein embolization versus dual vein embolization for management of the future liver remnant in patients undergoing major hepatectomy: meta-analysis

Background

This meta-analysis aimed to compare progression to surgery, extent of liver hypertrophy, and postoperative outcomes in patients planned for major hepatectomy following either portal vein embolization (PVE) or dual vein embolization (DVE) for management of an inadequate future liver remnant (FLR).

Methods

An electronic search was performed of MEDLINE, Embase, and PubMed databases using both medical subject headings (MeSH) and truncated word searches. Articles comparing PVE with DVE up to January 2022 were included. Articles comparing sequential DVE were excluded. ORs, risk ratios, and mean difference (MD) were calculated using fixed and random-effects models for meta-analysis.

Results

Eight retrospective studies including 523 patients were included in the study. Baseline characteristics between the groups, specifically, age, sex, BMI, indication for resection, and baseline FLR (ml and per cent) were comparable. The percentage increase in hypertrophy was larger in the DVE group, 66 per cent in the DVE group versus 27 per cent in the PVE group, MD 39.07 (9.09, 69.05) (P = 0.010). Significantly fewer patients failed to progress to surgery in the DVE group than the PVE group, 13 per cent versus 25 per cent respectively OR 0.53 (0.31, 0.90) (P = 0.020). Rates of post-hepatectomy liver failure 13 per cent versus 22 per cent (P = 0.130) and major complications 20 per cent versus 28 per cent (Clavien–Dindo more than IIIa) (P = 0.280) were lower. Perioperative mortality was lower with DVE, 1 per cent versus 10 per cent (P = 0.010)

Conclusion

DVE seems to produce a greater degree of hypertrophy of the FLR than PVE alone which translates into more patients progressing to surgery. Higher quality studies are needed to confirm these results.

Liver venous deprivation versus associating liver partition and portal vein ligation for staged hepatectomy for colo-rectal liver metastases: a comparison of early and late kinetic growth rates, and perioperative and oncological outcomes

BACKGROUND

Different techniques have been developed to optimize the Future Liver Remnant (FLR). Associated liver partition and portal vein ligation for staged hepatectomy (ALPPS) and liver venous deprivation (LVD) have shown the higher hypertrophy rates, but their place in clinical practice is still debated.

METHODS

Thirty-two consecutive ALPPS and LVD procedures for CRLM performed between December 2015 and December 2019 were included. This retrospective study evaluated kinetic growth rates (KGR) as primary outcome, and perioperative and oncological outcomes as secondary endpoints.

RESULTS

A total of 17 patients underwent LVD before surgery, whereas 15 underwent ALPPS. On early evaluation (7 vs 9 days, respectively), KGR did not differ between ALPPS and LVD cohort (0.8% per day vs 0.3% per day, p = 0.70; 23 cc/day vs 26 cc/day, p = 0.31). Late evaluation (21 vs 9 days) showed a KGR significantly decreased in the LVD group (0.6% per day vs 0.2% per day, p = 0.21; 20 cc/day vs 10 cc/day p = 0.02). Mean FLR-V increase was comparable in the two groups (60% vs 49%, p 0.32). Successful resection rate was 100% and 94% in LVD and ALPPS group, respectively. The hospital stay (p < 0.0001) and severe complications rate (p = 0.05) were lower after LVD. One and 3-years overall survival (OS) were 72,7% and 27,4% in the ALPSS group, versus 81,3% and 54,7% in LVD group (p = 0.10). The Median DFS was comparable between both techniques (6.1 months and 5.9 respectively, p = 0.66).

CONCLUSIONS

LVD and ALPPS shows similar KGR during the early period following preparation as well as similar survival outcomes. Hospital stay and severe complications are lower after LVD.

Leaping the Boundaries in Laparoscopic Liver Surgery for Hepatocellular Carcinoma

Simple Summary

Recent advances in surgical techniques and perioperative management lead to a redefinition of the actual frontiers of Laparoscopic Liver Resection (LLR) by including patients with more advanced disease. Nonetheless, because of both underlying liver conditions and technical difficulty, LLR for Hepatocellular Carcinoma (HCC) is still considered as a challenging procedure. Specific concerns exist about LLR in cirrhotic patients, posterosuperior segments, giant and multiple tumors, as well as repeat resections. This review focuses on the specific limits of this approach in HCC patients in order to put into practice all the pre- and intra-operative precautions to overcome their boundaries, making this technique the standard of care within high-volume hepatobiliary centers.

Abstract

The minimally invasive approach for hepatocellular carcinoma (HCC) had a slower diffusion compared to other surgical fields, mainly due to inherent peculiarities regarding the risks of uncontrollable bleeding, oncological inadequacy, and the need for both laparoscopic and liver major skills. Recently, laparoscopic liver resection (LLR) has been associated with an improved postoperative course, including reduced postoperative decompensation, intraoperative blood losses, length of hospitalization, and unaltered oncological outcomes, leading to its adoption within international guidelines. However, LLR for HCC still faces several limitations, mainly linked to the impaired function of underlying parenchyma, tumor size and numbers, and difficult tumor position. The aim of this review is to highlight the state of the art and future perspectives of LLR for HCC, focusing on key points for overcoming currents limitations and pushing the boundaries in minimally invasive liver surgery (MILS).

Imaging-guided interventions modulating portal venous flow: evidence and controversies

Portal hypertension is defined by an increase in the portosystemic venous gradient. In most cases, increased resistance to portal blood flow is the initial cause of elevated portal pressure. More than 90% of cases of portal hypertension are estimated to be due to advanced chronic liver disease or cirrhosis. Transjugular intrahepatic portosystemic shunts, a non-pharmacological treatment for portal hypertension, involve the placement of a stent between the portal vein and the hepatic vein or inferior vena cava which helps bypass hepatic resistance. Portal hypertension may also be a result of extrahepatic portal vein thrombosis or compression. In these cases, percutaneous portal vein recanalisation restores portal trunk patency, thus preventing portal hypertension-related complications. Any portal blood flow impairment leads to progressive parenchymal atrophy and triggers hepatic regeneration in preserved areas. This provides the rationale for using portal vein embolisation to modulate hepatic volume in preparation for extended hepatic resection. The aim of this paper is to provide a comprehensive evidence-based review of the rationale for, and outcomes associated with, the main imaging-guided interventions targeting the portal vein, as well as to discuss the main controversies around such approaches.

Minimizing the risk of small-for-size syndrome after liver surgery

BACKGROUND

Primary and secondary liver tumors are not always amenable to resection due to location and size. Inadequate future liver remnant (FLR) may prevent patients from having a curative resection or may result in increased postoperative morbidity and mortality from complications related to small-for-size syndrome (SFSS).

DATA SOURCES

This comprehensive review analyzed the principles, mechanism and risk factors associated with SFSS and presented current available options in the evaluation of FLR when planning liver surgery. In addition, it provided a detailed description of specific modalities that can be used before, during or after surgery, in order to optimize the conditions for a safe resection and minimize the risk of SFSS.

RESULTS

Several methods which aim to reduce tumor burden, preserve healthy liver parenchyma, induce hypertrophy of FLR or prevent postoperative complications help minimize the risk of SFSS.

CONCLUSIONS

With those techniques the indications of radical treatment for patients with liver tumors have significantly expanded. The successful outcome depends on appropriate patient selection, the individualization and modification of interventions and the right timing of surgery.

Future remnant Liver optimization: preoperative assessment, volume augmentation procedures and management of PVE failure

Surgery is the cornerstone treatment for patients with primary or metastatic hepatic tumors. Thanks to surgical and anesthetic technological advances, current indications for liver resections have been significantly expanded to include any patient in whom all disease can be resected with a negative margin (R0) while preserving an adequate future residual liver (FRL). Post-hepatectomy liver failure (PHLF) is still a feared complication following major liver surgery, associated with high morbidity, mortality and cost implications. PHLF is mainly linked to both the size and quality of the FRL. Significant advances have been made in detailed preoperative assessment, to predict and mitigate this complication, even if an ideal methodology has yet to be defined. Several procedures have been described to induce hypertrophy of the FRL when needed. Each technique has its advantages and limitations, and among them portal vein embolization (PVE) is still considered the standard of care. About 20% of patients after PVE fail to undergo the scheduled hepatectomy, and newer secondary procedures, such as segment 4 embolization, ALPPS and HVE, have been proposed as salvage strategies. The aim of this review is to discuss the current modalities available and new perspectives in the optimization of FRL in patients undergoing major liver resection.

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.

Combination of portal vein embolization and neoadjuvant chemotherapy for locally advanced gallbladder cancer requiring extended hepatectomy - A novel approach

BACKGROUND

Locally advanced gallbladder cancer (GBC) may require extended hepatectomy. Portal vein embolization (PVE) can lead to hypertrophy of future liver remnant (FLR), and neoadjuvant chemotherapy (NACT) can be used in this cohort, with additional advantage of downstaging tumors as well as preventing progression while waiting for liver regeneration. Here, we share our experience of combining NACT along with PVE in locally advanced GBC requiring major hepatectomy.

METHODS

Retrospective analysis of prospectively maintained database was conducted for patients with locally advanced GBC who underwent PVE and received NACT between 2012 and 2018.

RESULTS

Fourteen patients with locally advanced GBC underwent PVE and NACT. Median baseline FLR volume was 25.09% with a median degree of hypertrophy of 8.8% after PVE. Out of 14 patients, 7 (50%) underwent curative resection. Median overall survival in resectable and unresectable patients was 27 months and 15 months respectively.

CONCLUSION

PVE along with NACT made curative surgery feasible in half of the patients who were deemed unresectable initially.

Portal vein embolization: rationale, techniques, outcomes and novel strategies

The incidence of liver cancer has grown in the past decade, with 905,677 new cases and 830,180 deaths in 2020. According to the highest annual fatality ratio, liver cancer is the third-leading cause of cancer-related deaths worldwide. Surgical resection is the mainstay treatment for long-term survival. However, only 25% of patients are surgical candidates. Recent surgical concepts, techniques and multidisciplinary management were developed, including interventional radiology procedures that improve the management algorithm, expand the indications and limit dropouts from curative treatment. This review summarizes up-to-date information on interventional radiology in the management of liver tumors.

Liver Venous Deprivation (LVD) or Associating Liver Partition and Portal Vein Ligation for Staged Hepatectomy (ALPPS)?: A Retrospective Multicentric Study

OBJECTIVE

To compare two techniques of remnant liver hypertrophy in candidates for extended hepatectomy: radiological simultaneous portal vein (PVE) and hepatic vein embolization (HVE); namely liver venous deprivation (LVD), and ALPPS.

SUMMARY BACKGROUND DATA

Recent advances in chemotherapy and surgical techniques have widened indications for extended hepatectomy, before which remnant liver augmentation is mandatory. ALPPS and LVD typically show higher hypertrophy rates than PVE, but their respective places in patient management remain unclear.

METHODS

All consecutive ALPPS and LVD procedures performed in eight French centers between 2011 and 2020 were included. The main endpoint was the successful resection rate (resection rate without 90-day mortality) analyzed according to an intention-to-treat principle. Secondary endpoints were hypertrophy rates, intra- and post-operative outcomes.

RESULTS

Among 209 patients, 124 had LVD 37 [13,1015] days before surgery, while 85 underwent ALPPS with an inter-stages period of 10 [6, 69] days. ALPPS was mostly-performed for colorectal liver metastases (CRLM), LVD for CRLM and perihilar cholangiocarcinoma. Hypertrophy was faster for ALPPS. Successful resection rates were 72.6% for LVD ± rescue ALPPS (n=6) versus 90.6% for ALPPS (p<0.001). Operative duration, blood losses and length-of-stay were lower for LVD, while 90-day major complications and mortality were comparable. Results were globally unchanged for CRLM patients, or after excluding the early 2 years of experience (learning-curve effect).

CONCLUSIONS

This study is the first one comparing LVD versus ALPPS in the largest cohort so far. Despite its retrospective design, it yields original results that may serve as the basis for a prospective study.

The effects of physical prehabilitation: Improved liver regeneration and mitochondrial function after ALPPS operation in a rodent model

BACKGROUND

To identify the role of physical prehabilitation (PP) in liver regeneration, mitochondrial function, biogenesis, and inflammatory response was investigated after associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) in a rodent model.

METHODS

Male Wistar rats (n = 60) underwent ALPPS. Animals were divided (n = 30) to the physical prehabilitation group (PP) and sedentary group (S). The animals were exsanguinated before (0 hour) and 24, 48, 72, or 168 hours after the operation. Regeneration rate and proliferation index were assessed. Mitochondrial function, biogenesis, and inflammatory response were evaluated.

RESULTS

Regeneration rate and Ki67 index were significantly increased in the PP group compared to the S group (P < .001). Due to the changes in oxidative capacity and ATP production rate, the P/O ratio of PP group compared to the S group was significantly increased (P < .05). PP group was characterized by accelerated mitochondrial biogenesis and less intense inflammatory response compared to the S group.

CONCLUSIONS

To our knowledge, this is the first demonstration of the beneficial effects of PP on liver regeneration, mitochondrial function, biogenesis, and the inflammatory response after ALPPS.

Personalized Preoperative Nomograms Predicting Postoperative Risks after Resection of Perihilar Cholangiocarcinoma

INTRODUCTION

Curative treatment of perihilar tumors requires major hepatectomy responsible for high morbidity and mortality. Current nomograms are based on definitive pathological analysis, not usable for patient selection. Our aim was to propose preoperative predictors for severe morbidity (Dindo-Clavien ≥3) and mortality at sixth month after resection of perihilar tumors.

PATIENTS AND METHODS

We reviewed perioperative data of 186 patients operated with major hepatectomy for perihilar tumors between 2012 and 2018 in two high-volume centers. Univariate and multivariate analysis were performed to determine the preoperative predictors of morbidity and mortality. A stepwise regression in forward direction was developed to select variables for definitive models. Hosmer-Lemeshow test, Akaike information criteria and area under the ROC curves were calculated to validate both nomograms.

RESULTS

Resections were indicated for perihilar and intrahepatic cholangiocarcinoma in 125 and 61 cases, respectively. Severe complications occurred in 76 patients (40.8%). Nineteen patients (10.2%) deceased before the sixth postoperative month. The predictors of severe morbidity were: male gender, portal vein embolization, planned biliary resection, low psoas muscle area/height² and low hemoglobinemia. The predictors of early mortality were: age, high bilirubinemia, hypoalbuminemia, biliary drainage and long drainage-to-surgery interval. For both models, the p values of Hosmer-Lemeshow tests were of 0.9 and 0.99, respectively, the Akaike information criteria were of 35.5 and 37.7, respectively, and area under the curves was of 0.73 and 0.86, respectively.

CONCLUSION

We developed two accurate and practical nomograms based on exclusively preoperative data to predict early outcomes following the resection of perihilar tumors. If validated in larger series, these tools could be integrated in the decision-making process for patient selection.

Portal vein embolization with N-butyl cyanoacrylate glue is superior to other materials: a systematic review and meta-analysis

OBJECTIVES

It remains uncertain which embolization material is best for portal vein embolization (PVE). We investigated the various materials for effectiveness in inducing future liver remnant (FLR) hypertrophy, technical and growth success rates, and complication and resection rates.

METHODS

A systematic review from 1998 to 2019 on embolization materials for PVE was performed on Pubmed, Embase, and Cochrane. FLR growth between the two most commonly used materials was compared in a random effects meta-analysis. In a separate analysis using local data (n = 52), n-butyl cyanoacrylate (NBCA) was compared with microparticles regarding costs, radiation dose, and procedure time.

RESULTS

In total, 2896 patients, 61.0 ± 4.0 years of age and 65% male, from 51 papers were included in the analysis. In 61% of the patients, either NBCA or microparticles were used for embolization. The remaining were treated with ethanol, gelfoam, or sclerosing agents. The FLR growth with NBCA was 49.1% ± 29.7 compared to 42.2% ± 40 with microparticles (p = 0.037). The growth success rate with NBCA vs microparticles was 95.3% vs 90.7% respectively (p < 0.001). There were no differences in major complications between NBCA and microparticles. In the local analysis, NBCA (n = 41) entailed shorter procedure time and reduced fluoroscopy time (p < 0.001), lower radiation exposure (p < 0.01), and lower material costs (p < 0.0001) than microparticles (n = 11).

CONCLUSION

PVE with NBCA seems to be the best choice when combining growth of the FLR, procedure time, radiation exposure, and costs.

KEY POINTS

• The meta-analysis shows that n-butyl cyanoacrylate (NBCA) is superior to microparticles regarding hypertrophy of the future liver remnant, 49.1% ± 29.7 vs 42.2% ± 40.0 (p = 0.037). • There is no significant difference in major complication rates for portal vein embolization using NBCA, 4% (24/681), compared with microparticles, 5% (25/494) (p > 0.05). • Local data shows a shorter procedure time, 215 vs 348 mins from arrival to departure at the interventional radiology unit, and fluoroscopy time, 43 vs 96 mins (p < 0.001), lower radiation dosage, 573 vs 1287 Gycm² (p < 0.01), and costs, €816 vs €4233 (p < 0.0001) for NBCA compared to microparticles.

Preoperative Portal Vein Embolization for Liver Resection: An updated meta-analysis

Background: Portal vein embolization (PVE) is performed before major liver resection to increase liver volume remnant, controversy remains on the adverse effect of PVE on liver tumor patients. The current study highlighted the effect of PVE on the degree of hypertrophy of future liver remnant (FLR) and summarized PVE-related complications, aiming to provide a guideline for surgeons.

Methods: A search of current published studies on PVE was performed. Meta-analysis was conducted to assess the effect of PVE on hypertrophy of FLR and summarized PVE-related complications.

Results: 26 studies including 2335 patients were enrolled in the meta-analysis. All enrolled studies reported data regarding FLR hypertrophy rate, pooled effect size (ES) for FLR hypertrophy rate using a fixed-effect model was 0.105 (95%CI: 0.094-0.117, p=0.000), indicating PVE is favored in inducing FLR hypertrophy. Metatrim method indicated no obvious evidence of publication bias in the present meta-analysis. 247 (10.6%) patients exhibited PVE-related complications, receiving expectant treatment without affecting planned liver resection. Total 1782 patients (76%) underwent a subsequent liver resection after PVE, which is an encouraging result comparing with traditional resection rate in liver tumor patients.

Conclusions: PVE is a safe and effective procedure with a low occurrence of related complications for inducing sufficient hypertrophy of FLR in liver tumor patients, which could elevate the resection rate of liver tumor patients. Careful patient cohort selection is crucial to avoid overuse of PVE in technically resectable patients. Further multiple central clinical trials are conducive to select optimal patient cohorts and provide a guideline for surgeons.

Portal and hepatic vein embolization prior to major hepatectomy

PURPOSE

 To analyze safety and effectiveness of simultaneous portal and hepatic vein embolization (PHVE) or sequential hepatic vein embolization (HVE) compared to portal vein embolization (PVE) for future remnant liver (FRL) hypertrophy prior to major hepatic surgery.

METHODS

 Patients undergoing PVE, PHVE or HVE at our tertiary care center between 2018 and 2020 were retrospectively included. FRLV, standardized FRLV (sFRLV) and sFRLV growth rate per day were assessed via volumetry, as well as laboratory parameters.

RESULTS

 36 patients (f = 15, m = 21; median 64.5 y) were included, 16 patients received PHVE and 20 patients PVE, of which 4 received sequential HVE. Significant increase of FRLV was achieved with both PVE and PHVE compared to baseline (p < 0.0001). sFRLV growth rate did not significantly differ following PHVE (2.2 ± 1.2 %/d) or PVE (2.2 ± 1.7 %/d, p = 0.94). Left portal vein thrombosis (LPVT) was observed after PHVE in 6 patients and in 1 patient after PVE. Sequential HVE showed a considerably high growth rate of 1.42 ± 0.45 %/d after PVE.

CONCLUSION

 PHVE effectively induces FRL hypertrophy but yields comparable sFRLV to PVE. Sequential HVE further induces hypertrophy after insufficient growth due to PVE. Considering a potentially higher rate of LPVT after PHVE, PVE might be preferred in patients with moderate baseline sFRLV, with optional sequential HVE in non-sufficient responders.

Oncological Outcomes after Liver Venous Deprivation for Colorectal Liver Metastases: A Single Center Experience

Colorectal liver metastases (CRLM) are the major cause of death in patients with colorectal cancer (CRC). The cornerstone treatment of CRLM is surgical resection. Post-operative morbidity and mortality are mainly linked to an inadequate future liver remnant (FLR). Nowadays preoperative portal vein embolization (PVE) is the most widely performed technique to increase the size of the future liver remnant (FLR) before major hepatectomies. One method recently proposed to increase the FLR is liver venous deprivation (LVD), but its oncological impact is still unknown. The aim of this study is to report first short- and long-term oncological outcomes after LVD in patients undergoing right (or extended right) hepatectomy for CRLM. Seventeen consecutive patients undergoing LVD between July 2015 and May 2020 before an (extended) right hepatectomy were retrospectively analyzed from an institutional database. Post-operative and follow-up data were analyzed and reported. Primary outcomes were 1-year and 3-year overall survival (OS) and hepatic recurrence (HR). Postoperative complications occurred in 8 patients (47%). No deaths occurred after surgery. HR occurred in 9 patients (52.9%). 1-year and 3-year OS were 87% (95% confidence interval [CI]: ±16%) and 60.3%, respectively (95% CI: ±23%). Median Disease-Free Survival (DFS) was 6 months (CI 95%: 4.7-7.2). With all the limitations of a retrospective study with a small sample size, LVD showed similar oncological outcomes compared to literature reports for Portal Vein Embolization (PVE).

Major hepatectomy decreased tumor growth in an experimental model of bilobar liver metastasis

BACKGROUND/PURPOSE

Two-stage hepatectomy (TSH), is associated with a risk of drop-out due to tumoral progression following portal vein occlusion (PVO). We explored the impact of majorhepatectomy on tumor growth by objective radiological measures comparing to PVO and minor hepatectomy, using a model of bilobar colorectal liver metastasis (CLM).

METHODS

CLM were induced in 48 BDIX rats by injection of DHDK12-cells. 7 days after cells injection, animals were distributed into 4 groups of equal number (n = 12): portal vein ligation (PVL), sham laparotomy (sham), minor (30%Phx) and major (70%Phx) hepatectomy. MR imaging was used for in vivo analysis of tumor implantation, growth and volumes.

RESULTS

At POD10, tumour volumes were homogeneously distributed among the 4 groups. Lower TV were significantly observed after 70%Phx comparing to PVL at POD17 (0.63 ± 0.14cm3 vs 0.9 ± 0.16cm3, p = 0.008) and to the 3 others groups at POD24: 1.78 ± 0.38cm3 vs 3.2 ± 0.62cm3 (PVL, p = 0.019), 2.41 ± 0.74cm3 (Sham, p = 0.024) and 2.32 ± 0.59cm3 (30%PHx, p = 0.019).

CONCLUSION

We confirmed in a reproducible model that contrary to PVO, a major hepatectomy decreases the growth of CLM in the remnant liver. This result leads to questioning the usual TSH and justifies exploring alternative strategies. The "major hepatectomy first-approach" should be an option to be evaluated.

Radiological Simultaneous Portohepatic Vein Embolization (RASPE) Before Major Hepatectomy: A Better Way to Optimize Liver Hypertrophy Compared to Portal Vein Embolization

OBJECTIVE

The aim of this retrospective study was to compare portal vein embolization (PVE) and radiologica simultaneous portohepatic vein embolization (RASPE) for future liver remnant (FLR) growth in terms of feasibility, safety, and efficacy.

SUMMARY OF BACKGROUND DATA

After portal vein embolization (PVE), 15% of patients remain ineligible for hepatic resection due to insufficient hypertrophy of the FLR. RASPE has been proposed to induce FLR growth.

MATERIALS AND METHODS

Between 2016 and 2018, 73 patients were included in the study. RASPE was proposed for patients with a ratio of FLR to total liver volume (FLR/TLV) of <25% (RASPE group). This group was compared to patients who underwent PVE for a FLR/TLV <30% (PVE group). Patients in the 2 groups were matched for age, sex, type of tumor, and number of chemotherapy treatments. FLR was assessed by computed tomography before and 4 weeks after the procedure.

RESULTS

The technical success rate in both groups was 100%. Morbidity post-embolization, and the time between embolization and surgery were similar between the groups. In the PVE group, the FLR/TLV ratio before embolization was 31.03% (range: 18.33%-38.95%) versus 22.91% (range: 16.55-32.15) in the RASPE group (P < 0.0001). Four weeks after the procedure, the liver volume increased by 28.98% (range: 9.31%-61.23%) in the PVE group and by 61.18% (range: 23.18%-201.56%) in the RASPE group (P < 0.0001). Seven patients in the PVE group, but none in the RASPE group, had postoperative liver failure (P = 0.012).

CONCLUSIONS

RASPE can be considered as "radiological associating liver partition and portal vein ligation for staged hepatectomy." RASPE induced safe and profound growth of the FLR and was more efficient than PVE. RASPE also allowed for extended hepatectomy with less risk of post-operative liver failure.

New frontiers in liver resection for hepatocellular carcinoma

Liver resection is one of the main curative options for early hepatocellular carcinoma (HCC) in patients with cirrhosis and is the treatment of choice in non-cirrhotic patients. However, careful patient selection is required to balance the risk of postoperative liver failure and the potential benefit on long-term outcomes. In the last decades, improved surgical techniques and perioperative management, as well as better patient selection, have enabled the indications for liver resection to be expanded. In this review, we aim to describe the main indications for liver resection in the management of HCC, its role compared to percutaneous ablation and liver transplantation in the therapeutic algorithm, as well as the recent advances in liver surgery that could be used to improve the prognosis of patients with HCC.

Liver regeneration and liver metastasis

Surgical resection for primary and secondary hepatic neoplasms provides the best chance of cure. Advanced surgical techniques such as portal vein embolisation, two-staged hepatectomy and associated liver partition and portal vein ligation for staged-hepatectomy (ALPPS) have facilitated hepatic resection in patients with previously unresectable, bi-lobar disease. These techniques are frequently employed to ensure favourable clinical outcomes and avoid potentially fatal post-operative complications such as small for size syndrome and post-hepatectomy liver failure. However, they rely on the innate ability of the liver to regenerate. As our knowledge of liver organogenesis, liver regeneration and hepatocarcinogenesis has expanded in recent decades it has come to light that liver regeneration may also drive tumour recurrence. Clinical studies in patients undergoing portal vein embolisation indicate that tumours may progress following the procedure in concordance with liver regeneration and hypertrophy, however overall survival in these patients has not been shown to be worse. In this article, we delve into the mechanisms underlying liver regeneration to better understand the complex ways in which this may affect tumour behaviour and ultimately inform clinical decisions.

Combined hepatic and portal vein embolization as preparation for major hepatectomy: a systematic review

BACKGROUND

Some patients remain deemed unsuitable for resection after portal vein embolization (PVE) because of insufficient hypertrophy of the future remnant liver (FRL). Hepatic and portal vein embolization (HPVE) has been shown to induce hypertrophy of the FRL. The aim of this study was to provide a systematic review of the available literature on HPVE as preparation for major hepatectomy.

METHODS

The literature search was performed on online databases. Studies including patients who underwent preoperative HPVE were retrieved for evaluation.

RESULTS

Six articles including 68 patients were published between 2003 and 2017. HPVE was performed successfully in all patients with no mortality and morbidity-related procedures. The degree of hypertrophy of the FRL after HPVE ranged from 33% to 63.3%. Surgical resection after preoperative HPVE could be performed in 85.3% of patients, but 14.7% remained unsuitable for resection because of insufficient hypertrophy of the FRL or tumor progression. Posthepatectomy morbidity and mortality rates were 10.3% and 5.1%, respectively. The postoperative liver failure rate was nil.

CONCLUSION

HPVE as a preparation for major hepatectomy appears to be feasible and safe and could increase the resectability of patients initially deemed unsuitable for resection because of absent or insufficient hypertrophy of the FRL after PVE alone.