Effect of portal vein embolisation on the growth rate of colorectal liver metastases

Simultaneous Liver Venous Deprivation Following Hepatic Arterial Chemoembolization Before Major Hepatectomy for Hepatocellular Carcinoma: A New Methods to Achieve Hypertrophy Liver Remnant

Purpose

Liver venous deprivation (LVD; simultaneous portal vein embolization and hepatic vein embolization) has been the latest surgical strategy for rapid future liver remnant (FLR) hypertrophy. The aim of this study was to assess the feasibility, safety, and efficacy of simultaneous LVD following hepatic arterial chemoembolization (TACE-LVD) before major hepatectomy for hepatocellular carcinoma (HCC).

Patients and Methods

A retrospective analysis of the outcomes of 23 HCC patients who underwent TACE-LVD at our center between October 2019 and October 2023 was conducted. An assessment of postoperative complications, FLR volume, liver function, and tumor response was performed.

Results

All patients successfully underwent TACE-LVD. No other serious complications occurred except in 1 patient who underwent puncture drainage due to excessive pleural effusion. Following TACE-LVD, transaminase levels peak two days before rapidly decreasing and return to preoperative levels within one week. The ratio of FLR to standardized liver volume increased from 35.9% (interquartile range [IQR], 8.6) to 46.4% (IQR, 8.2), with a mean degree of hypertrophy and kinetic growth rate of 13.2% (IQR, 5.4) and 4.4% (IQR, 1.8) per week, respectively. At the first assessment after TACE-LVD, most patients exhibited sufficient FLR for hepatectomy, except for 4 patients with cirrhosis. The modified response evaluation criteria for solid tumor assessment revealed a disease control rate of 95.7%, with only 1 patient (Barcelona Clinic Liver Cancer stage C) developing intrahepatic disease progression.

Conclusion

TACE-LVD seems to be a feasible, safe, and effective strategy for rapid FLR hypertrophy. Moreover, TACE-LVD may be a therapeutic choice if insufficient FLR hypertrophy precludes resection. This strategy warrants further exploration.

Preoperative imaging of colorectal liver metastases: what the radiologist and the multidisciplinary team need to know

The management of patients with colorectal liver metastases (CRLM) has transformed over the past 2 decades. Advances in surgical techniques, systemic therapies, and local treatments have resulted in a paradigm shift. Disease that would once have been considered terminal is now frequently treated aggressively with both a disease-free and overall survival benefit. In line with the expanding range of treatment options, there has been an increase in the volume and complexity of imaging required in the management of these patients to ensure optimal patient selection and outcome. The radiologist plays a pivotal role in interpreting these studies, conveying the relevant information and informing the discussion at multidisciplinary team meetings. The purpose of this review is to provide an update for radiologists on the current surgical management of patients with CRLM highlighting specific imaging information that is required by the multidisciplinary team when assessing resectability and/or the need for additional liver-directed therapies.

Catheter-Directed Ionic Liquid Embolic Agent for Rapid Portal Vein Embolization, Segmentectomy, and Bile Duct Ablation

Embolic materials currently in use for portal vein embolization (PVE) do not treat the tumor, which poses a risk for tumor progression during the interval between PVE and surgical resection. Here, is developed an ionic-liquid-based embolic material (LEAD) for portal vein embolization, liver ablation, and drug delivery. LEAD is optimized and characterized for diffusivity, X-ray visibility, and cytotoxicity. In the porcine renal embolization model, LEAD delivered from the main renal artery reached vasculature down to 10 microns with uniform tissue ablation and delivery of small and large therapeutics. In non-survival and survival porcine experiments, successful PVE is achieved in minutes, leading to the expected chemical segmentectomy, and delivery of a large protein drug (i.e., Nivolumab) with LEAD. In cholangiocarcinoma mouse tumor models and in ex vivo human tumors, LEAD consistently achieved an effective ablation and wide drug distribution. Furthermore, various strains of drug-resistant patient-derived bacteria showed significant susceptibility to LEAD, suggesting that LEAD may also prevent infectious complications resulting from tissue ablation. With its capabilities to embolize, ablate, and deliver therapeutics, ease of use, and a high safety profile demonstrated in animal studies, LEAD offers a potential alternative to tumor ablation with or without PVE for FLR growth.

IL-22 promotes liver regeneration after portal vein ligation

Background

Insufficient remnant liver volume (RLV) after the resection of hepatic malignancy could lead to liver failure and mortality. Portal vein ligation (PVL) prior to hepatectomy is subsequently introduced to increase the remnant liver volume and improve the outcome of hepatic malignancy. IL-22 has previously been reported to promote liver regeneration, while facilitating tumor development in the liver via Steap4 upregulation. Here we performed PVL in mouse models to study the role of IL-22 in liver regeneration post-PVL.

Methods

Liver weight and volume was measured via magnetic resonance imaging (MRI). Immunohistochemistry for Ki67 and hepatocyte growth factor (HGF) was performed. IL-22 was analyzed by flow cytometry and quantitative polymerase chain reaction (qPCR) was used for acquisition of Il-33, Steap4, Fga, Fgb and Cebpd. To analyze signaling pathways, mice with deletion of STAT3 and a neutralizing antibody for IL-22 were used.

Results

The remnant liver weight and volume increased over time after PVL. Additionally, we found that liver regenerative molecules, including Ki67 and HGF, were significantly increased in remnant liver at day 3 post-PVL, as well as IL-22. Administration of IL-22 neutralizing antibody could reduce Ki67 expression after PVL. The upregulation of IL-22 after PVL was mainly derived from innate cells. IL-22 blockade resulted in lower levels of IL-33 and Steap4 in the remnant liver, which was also the case in mice with deletion of STAT3, the main downstream signaling molecule of IL-22, in hepatocytes.

Conclusion

IL-22 promotes liver regeneration after PVL. Thus, a combination of IL-22 supplementation and Steap4 blockade could potentially be applied as a novel therapeutic approach to boost liver regeneration without facilitating tumor progression after PVL.

Contemporary Surgical Management of Colorectal Liver Metastases

Colorectal cancer is the third most common cancer in the United States and the second most common cause of cancer-related death. Approximately 20-30% of patients will develop hepatic metastasis in the form of synchronous or metachronous disease. The treatment of colorectal liver metastasis (CRLM) has evolved into a multidisciplinary approach, with chemotherapy and a variety of locoregional treatments, such as ablation and portal vein embolization, playing a crucial role. However, resection remains a core tenet of management, serving as the gold standard for a curative-intent therapy. As such, the input of a dedicated hepatobiliary surgeon is paramount for appropriate patient selection and choice of surgical approach, as significant advances in the field have made management decisions extremely nuanced and complex. We herein aim to review the contemporary surgical management of colorectal liver metastasis with respect to both perioperative and operative considerations.

90Y-/166Ho- 'Radiation lobectomy' for liver tumors induces abnormal morphology and impaired drainage of peritumor lymphatics

Background & Aims

High-dose unilobar radioembolization, or 'radiation lobectomy' (RL), is an induction therapy that achieves contralateral future liver remnant hypertrophy while simultaneously irradiating the tumor. As such, it may prevent further growth, but it is unknown whether RL affects intrahepatic lymphatics, a major route via which liver tumors disseminate.

Methods

This was a case-control study conducted at University Medical Center Utrecht. The study compared lymph vessels in livers that had undergone RL (cases) with those in livers that had not undergone RL (controls). Histological samples were acquired from patients diagnosed with hepatocellular carcinoma (HCC) or colorectal liver metastases (CRLM) between 2017 and 2022. Lymph vessel morphology was analyzed by two researchers using podoplanin, a protein that is expressed in lymphatic endothelium. In vivo liver lymph drainage of radioembolized livers was assessed using intraoperative liver lymphangiography (ILL): during liver surgery, patent blue dye was injected into the liver parenchyma, followed by inspection for staining of perihepatic lymph structures. ILL results were compared to a previously published cohort.

Results

Immunohistochemical analysis on post-RL tumor tissues from ten patients with CRLM and nine patients with HCC revealed aberrant morphology of irradiated liver lymphatics when compared to controls (n = 3 per group). Irradiated lymphatics were tortuous (p <0.05), thickened (p <0.05) and discontinuous (p <0.05). Moreover, post-RL lymphatics had larger lumens (1.5-1.7x, p <0.0001), indicating lymph stasis. ILL revealed diminished lymphatic drainage to perihepatic lymph nodes and vessels in irradiated livers when compared to non-radioembolized controls (p = 1.0x10-4).

Conclusions

Radioembolization impairs peritumoral lymph vessel function. Further research is needed to evaluate if radioembolization impairs tumor dissemination via this route.

Impact and implications

Unilobar radioembolization can serve as an alternative to portal venous embolization for patients who are considered unresectable due to an insufficient future liver remnant. This research suggests that radioembolization impairs the function of peritumoral liver lymph vessels, potentially hindering dissemination via this route. These findings provide support for considering unilobar radioembolization over standard portal venous embolization.

Impact of rapid hypertrophy of tourniquet associating liver partition and portal vein ligation in the tumor progression pathways compared to two stage hepatectomy in patients with colorectal liver metastases

BACKGROUND

It is not known if the inflammatory phenomena related to highly accelerated regeneration activate any signaling pathways that are associated with a major stimulus to colorectal liver metastases (CRLM) disease in tourniquet associating liver partition and portal vein ligation for staged hepatectomy (T-ALPPS) compared to two stage hepatectomy (TSH).

METHODS

Between January 2012 and April 2018, we prospectively performed biopsies from future liver remnant and deportalized lobe in CRLM patients undergoing T-ALPPS in both stages. Immunohistopathological analysis was performed on the above tissue samples and compared to biopsy samples from patients who underwent TSH for CRLM at our center between September 2000 and August 2011.

RESULTS

A total of 42 patients (20 TSH and 22 T-ALPPS) were included. There were no differences in the rates of recurrence, overall survival or any of the factors analyzed relating to tumor progression between stages 1 and 2. Regarding the anti-tumor effect, there was a significant reduction in the number of T-CD8 infiltrates in the second stage of TSH (12.5 vs. 5.5, p = 0.02).

CONCLUSION

The results suggest that liver regeneration with T-ALPPS does not induce higher tumor progression or significant immunological changes in the tumor environment when compared to classical TSH.

Dose finding study for unilobar radioembolization using holmium-166 microspheres to improve resectability in patients with HCC: the RALLY protocol

BACKGROUND

High dose unilobar radioembolization (also termed 'radiation lobectomy')-the transarterial unilobar infusion of radioactive microspheres as a means of controlling tumour growth while concomitantly inducing future liver remnant hypertrophy-has recently gained interest as induction strategy for surgical resection. Prospective studies on the safety and efficacy of the unilobar radioembolization-surgery treatment algorithm are lacking. The RALLY study aims to assess the safety and toxicity profile of holmium-166 unilobar radioembolization in patients with hepatocellular carcinoma ineligible for surgery due to insufficiency of the future liver remnant.

METHODS

The RALLY study is a multicenter, interventional, non-randomized, open-label, non-comparative safety study. Patients with hepatocellular carcinoma who are considered ineligible for surgery due to insufficiency of the future liver remnant (< 2.7%/min/m2 on hepatobiliary iminodiacetic acid scan will be included. A classical 3 + 3 dose escalation model will be used, enrolling three to six patients in each cohort. The primary objective is to determine the maximum tolerated treated non-tumourous liver-absorbed dose (cohorts of 50, 60, 70 and 80 Gy). Secondary objectives are to evaluate dose-response relationships, to establish the safety and feasibility of surgical resection following unilobar radioembolization, to assess quality of life, and to generate a biobank.

DISCUSSION

This will be the first clinical study to assess the unilobar radioembolization-surgery treatment algorithm and may serve as a stepping stone towards its implementation in routine clinical practice.

TRIAL REGISTRATION

Netherlands Trial Register NL8902 , registered on 2020-09-15.

A bibliometric and visualized analysis of preoperative future liver remnant augmentation techniques from 1997 to 2022

Background

The size and function of the future liver remnant (FLR) is an essential consideration for both eligibility for treatment and postoperative prognosis when planning surgical hepatectomy. Over time, a variety of preoperative FLR augmentation techniques have been investigated, from the earliest portal vein embolization (PVE) to the more recent Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) and liver venous deprivation (LVD) procedures. Despite numerous publications on this topic, no bibliometric analysis has yet been conducted.

Methods

Web of Science Core Collection (WoSCC) database was searched to identify studies related to preoperative FLR augmentation techniques published from 1997 to 2022. The analysis was performed using the CiteSpace [version 6.1.R6 (64-bit)] and VOSviewer [version 1.6.19].

Results

A total of 973 academic studies were published by 4431 authors from 920 institutions in 51 countries/regions. The University of Zurich was the most published institution while Japan was the most productive country. Eduardo de Santibanes had the most published articles, and Masato Nagino was the most frequently co-cited author. The most frequently published journal was HPB, and the most cited journal was Ann Surg, with 8088 citations. The main aspects of preoperative FLR augmentation technique is to enhance surgical technology, expand clinical indications, prevent and treat postoperative complications, ensure long-term survival, and evaluate the growth rate of FLR. Recently, hot keywords in this field include ALPPS, LVD, and Hepatobiliary Scintigraphy.

Conclusion

This bibliometric analysis provides a comprehensive overview of preoperative FLR augmentation techniques, offering valuable insights and ideas for scholars in this field.

Interventional radiological therapies in colorectal hepatic metastases

Colorectal malignancy is the third most common cancer and one of the prevalent causes of death globally. Around 20-25% of patients present with metastases at the time of diagnosis, and 50-60% of patients develop metastases in due course of the disease. Liver, followed by lung and lymph nodes, are the most common sites of colorectal cancer metastases. In such patients, the 5-year survival rate is approximately 19.2%. Although surgical resection is the primary mode of managing colorectal cancer metastases, only 10-25% of patients are competent for curative therapy. Hepatic insufficiency may be the aftermath of extensive surgical hepatectomy. Hence formal assessment of future liver remnant volume (FLR) is imperative prior to surgery to prevent hepatic failure. The evolution of minimally invasive interventional radiological techniques has enhanced the treatment algorithm of patients with colorectal cancer metastases. Studies have demonstrated that these techniques may address the limitations of curative resection, such as insufficient FLR, bi-lobar disease, and patients at higher risk for surgery. This review focuses on curative and palliative role through procedures including portal vein embolization, radioembolization, and ablation. Alongside, we deliberate various studies on conventional chemoembolization and chemoembolization with irinotecan-loaded drug-eluting beads. The radioembolization with Yttrium-90 microspheres has evolved as salvage therapy in surgically unresectable and chemo-resistant metastases.

Portal Vein Variations, Clinical Correlation, and Embryological Explanation: A Review Article

Portal vein (PV) is a large vein that collects blood from the abdominal part of gall bladder, pancreas, alimentary tract, and spleen and transports to the liver. One of the parts of the extraembryonic venous system, the vitelline veins, is where PV starts. In about five weeks of gestation, a venous plexus is formed, and variations in this plexus lead to portal variance. The junction of superior mesenteric and splenic veins is typically where the vein begins to network. There are five types of branching patterns of the right PV: conventional branching, trifurcation branching, early branching, separate segment 7 branching, and separate segment 6 branching. To perform pancreatic, duodenal, and liver surgeries, knowledge of variations in PV formation is important. For surgical and interventional operations to be accurate, it is crucial to understand the architecture of the PV and its anomalies. As distinct regions of the brain connect with one another, portal architecture is frequently observed in imaging investigations. Portal hypertension is characterized as an increase in blood pressure in the portal venous system (PVS) in the context of severe liver disease, such as cirrhosis. Non-invasive methods for examining the anatomy and anomalies of the PV include ultrasound, computed tomography (CT), and magnetic resonance (MR). There are many abnormalities of PVS that have been discussed in the articles such as Congenital PV Absence; PV Branches Congenitally Grow in Structure; Hypoplasia, Atresia, and Stenosis of the PV; and Portosystemic Shunts.

Prediction of left lobe hypertrophy after right lobe radioembolization of the liver using a clinical data model with external validation

In cirrhotic patients with hepatocellular carcinoma (HCC), right-sided radioembolization (RE) with Yttrium-90-loaded microspheres is an established palliative therapy and can be considered a "curative intention" treatment when aiming for sequential tumor resection. To become surgical candidate, hypertrophy of the left liver lobe to > 40% (future liver remnant, FLR) is mandatory, which can develop after RE. The amount of radiation-induced shrinkage of the right lobe and compensatory hypertrophy of the left lobe is difficult for clinicians to predict. This study aimed to utilize machine learning to predict left lobe liver hypertrophy in patients with HCC and cirrhosis scheduled for right lobe RE, with external validation. The results revealed that machine learning can accurately predict relative and absolute volume changes of the left liver lobe after right lobe RE. This prediction algorithm could help to estimate the chances of conversion from palliative RE to curative major hepatectomy following significant FLR 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.

Transarterial Radioembolization to Impact Liver Volumetry: When and How

Inadequate volume of the future liver remnant (FLR) renders many patients with liver malignancies not amenable to surgical resection. Depending on the health of the liver and the patient in general, an FLR of 25-40% is required to avoid acute post-hepatectomy liver failure. Transarterial radioembolization (TARE) of a diseased liver lobe leads to atrophy of the embolized lobe and compensatory hypertrophy of the contralateral lobe. Although the absolute degree of FLR hypertrophy seems to be comparable to portal vein embolization, the kinetic of hypertrophy is much slower after radioembolization. However, TARE has the unique advantages of simultaneously offering local tumor control, possibly downstaging disease, and providing biological test of time. Progressions in technique and personalized dosimetry allow for more predictable ablative treatment of liver malignancies and preparation for major liver surgery. This article provides an overview of the existing literature, discusses the evidence, and considers possible criteria for patient selection.

Current strategies to induce liver remnant hypertrophy before major liver resection

Hepatic resection is the gold standard for patients affected by primary or metastatic liver tumors but is hampered by the risk of post-hepatectomy liver failure. Despite recent improvements, liver surgery still requires excellent clinical judgement in selecting patients for surgery and, above all, efficient pre-operative strategies to provide adequate future liver remnant. The aim of this article is to review the literature on the rational, the preliminary assessment, the advantages as well as the limits of each existing technique for preparing the liver for major hepatectomy.

Radiation Lobectomy: An Overview of Concept and Applications, Technical Considerations, Outcomes

Surgical resection has long been considered curative for patients with early-stage hepatocellular carcinoma (HCC). However, inadequate future liver remnant (FLR) renders many patients not amenable to surgery. Recently, lobar administration of yttrium-90 (Y90) radioembolization has been utilized to induce FLR hypertrophy while providing disease control, eventually facilitating resection in patients with hepatic malignancy. This has been termed "radiation lobectomy (RL)." The concept is evolving, with modified approaches combining RL and high-dose curative-intent radioembolization (radiation segmentectomy) to achieve tumor ablation. This article provides an overview of the concept and applications of RL, including technical considerations and outcomes in patients with hepatic malignancies.

Review of Use of Y90 as a Bridge to Liver Resection and Transplantation in Hepatocellular Carcinoma

BACKGROUND

The incidence of hepatocellular carcinoma (HCC) has been rising, and 80% of HCCs are unresectable at the time of presentation. In recent years, Yttrium-90 (Y90) radioembolization has arisen as a potential tool to treat the primary HCC tumor while also inducing contralateral liver hypertrophy to increase future liver remnant volumes. The goal of this multidisciplinary review is to summarize the contemporary evidence on the safety, efficacy, and utility of Y90 as a bridge to liver resection and transplant in patients with HCC.

METHODS

A narrative review was conducted of the recent literature regarding the utilization of Y90 as a therapy prior to liver resection or transplant in patients with HCC. A specific emphasis was placed on articles published in the last 10 years.

RESULTS

Y90 radioembolization has demonstrated a high safety profile and increasing utility in bridging and downstaging patients with HCC who subsequently undergo liver resection or transplant. The continuous advancements in treatment strategies and radiation dosimetry have paved the way for the incorporation of Y90 in all stages of HCC with different intents, including downstaging and bridging.

CONCLUSIONS

Y90 radioembolization can be safely used in the HCC population to bridge patients to resection or transplantation, induce future liver remnant growth, and select for less aggressive tumor biology prior to surgery.

Portal vein embolization with n-butyl-cyanoacrylate before hepatectomy: a single-center retrospective analysis of 46 consecutive patients

BACKGROUND

Preoperative portal vein embolization (PVE) is performed to induce hypertrophy of the future liver remnant enabling major liver resection in patients with various types of liver tumors.

PURPOSE

To evaluate safety and effectiveness of PVE with n-butyl-cyanoacrylate (NBCA).

MATERIAL AND METHODS

All consecutive patients referred to our hospital for PVE between July 2006 and July 2017 were retrospectively reviewed. Volumetry was performed on computed tomography images before and after PVE, segmenting the total liver volume and the future liver remnant (FLR), i.e. liver segments I-III.

RESULTS

PVE was performed in 46 patients (18 women, 28 men; mean age = 61 years) using local anesthesia. The ipsilateral technique was used in 45 patients. Adverse events were rare. The mean FLR volume increase was 56%, the degree of hypertrophy was 9.7%, and the kinetic growth rate was 2.1%/week. The median ± SD period between PVE and liver surgery was 7 ± 3 weeks. Forty-two patients (91%) had surgery; liver resection was performed in 37 (80%) patients. Three patients (7%) developed transient liver failure after surgery. There was no 90-day post-PVE or postoperative mortality.

CONCLUSION

PVE using NBCA through the ipsilateral approach in local anesthesia is safe and effective in inducing hypertrophy of the future liver remnant enabling surgery, and thereby increasing survival in patients with liver tumors.

MRI-Based Quantitation of Hepatic Steatosis Does Not Predict Hypertrophy Rate after Portal Vein Embolization in Patients with Colorectal Liver Metastasis and Normal to Moderately Elevated Fat Fraction

The aim of this study was to correlate the pre-procedural magnetic-resonance-imaging-based hepatic fat fraction (hFF) with the degree of hypertrophy after portal vein embolization (PVE) in patients with colorectal cancer liver metastases (CRCLM). Between 2011 November and 2020 February, 68 patients with CRCLM underwent magnetic resonance imaging (MRI; 1.5 Tesla) of the liver before PVE. Using T1w chemical shift imaging (DUAL FFE), the patients were categorized as having a normal (<5%) or an elevated (>5%) hFF. The correlation of hFF, age, gender, initial tumor mass, history of chemotherapy, degree of liver hypertrophy, and kinetic growth rate after PVE was investigated using multiple regression analysis and Spearman’s test. A normal hFF was found in 43/68 patients (63%), whereas 25/68 (37%) patients had an elevated hFF. The mean hypertrophy and kinetic growth rates in patients with normal vs. elevated hFF were 24 ± 31% vs. 28 ± 36% and 9 ± 9 % vs. 8 ± 10% (p > 0.05), respectively. Spearman’s test showed no correlation between hFF and the degree of hypertrophy (R = −0.04). Multivariable analysis showed no correlation between hFF, history of chemotherapy, age, baseline tumor burden, or laterality of primary colorectal cancer, and only a poor inverse correlation between age and kinetic growth rate after PVE. An elevated hFF in a pre-procedural MRI does not correlate with the hypertrophy rate after PVE and should therefore not be used as a contraindication to the procedure in patients with CRCLM.

The use of neoadjuvant lobar radioembolization prior to major hepatic resection for malignancy results in a low rate of post hepatectomy liver failure

Background

Neoadjuvant yttrium-90 transarterial radioembolization (TARE) is increasingly being used as a strategy to facilitate resection of otherwise unresectable tumors due to its ability to generate both tumor response and remnant liver hypertrophy. Perioperative outcomes after the use of neoadjuvant lobar TARE remain underinvestigated.

Methods

A single center retrospective review of patients who underwent lobar TARE prior to major hepatectomy for primary or metastatic liver cancer between 2007 and 2018 was conducted. Baseline demographics, radioembolization parameters, pre- and post-radioembolization volumetrics, intra-operative surgical data, adverse events, and post-operative outcomes were analyzed.

Results

Twenty-six patients underwent major hepatectomy after neoadjuvant lobar TARE. The mean age was 58.3 years (17-88 years). 62% of patients (n=16) had primary liver malignancies while the remainder had metastatic disease. Liver resection included right hepatectomy or trisegmentectomy, left or extended left hepatectomy, and sectorectomy/segmentectomy in 77% (n=20), 8% (n=2), and 15% (n=4) of patients, respectively. The mean length of stay was 8.3 days (range, 3-33 days) and there were no grade IV morbidities or 90-day mortalities. The incidence of post hepatectomy liver failure (PHLF) was 3.8% (n=1). The median time to progression after resection was 4.5 months (range, 3.3-10 months). Twenty-three percent (n=6) of patients had no recurrence. The median survival was 28.9 months (range, 16.9-46.8 months) from major hepatectomy and 37.6 months (range, 25.2-53.1 months) from TARE.

Conclusions

Major hepatectomy after neoadjuvant lobar radioembolization is safe with a low incidence of PHLF.

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.

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.

Faster Return to Intended Oncologic Treatment (RIOT) After Trisectionectomy Does Not Translate to Better Outcomes

BACKGROUND

Resection with trisectionectomy may necessitate liver molding for adequate future liver remnant (FLR), and subsequent complications can impact return to intended oncologic therapy (RIOT). This study evaluated whether a difference in RIOT exists with the use of molding and between liver molding techniques (associating liver partition and portal vein ligation for staged hepatectomy [ALPPS] and portal vein embolization [PVE]) with trisectionectomy.

METHODS

A retrospective review evaluated trisectionectomies for malignancy. Outcomes were compared with and without molding, and RIOT was determined.

RESULTS

Fifty-one patients underwent trisectionectomy: 11 ALPPS, 14 PVE, 26 without molding. 73% of ALPPS, 64% of PVE, and 58% without molding achieved RIOT (P = .971). There were no differences found in baseline characteristics, R0 rate, length of stay, readmission, complications, or mortality. Time to RIOT was significantly different (ALPPS: 3.3 months; PVE: 5.2 months; none: 2.4 months, P = .0203). There were no differences in recurrence or survival.

CONCLUSIONS

Liver molding should not cause apprehension as there are no differences in achieving RIOT. Although technique alters time to RIOT, this does not translate into improved outcomes, implicating disease biology, and regeneration stimulus.

Expression of MMP-2 in residual VX2 liver tumor after transcatheter arterial embolization combined with portal venous embolization in an animal model

Objective

This study aimed to analyze the effects of transcatheter arterial embolization (TAE) combined with portal venous embolization (PVE) on the expression of MMP-2 in residual VX2 liver tumor tissues, liver function and non-embolic lobe regeneration.

Methods

A total of 72 rabbits were randomly divided into Sham, TAE, PVE and TAE ​+ ​PVE groups (n ​= ​18/group). The tissue samples from each group were taken at 6 ​h, 3 days and 7 days after interventional operation, respectively. MMP-2 expression was detected by immunohistochemistry, Real-time PCR, and Western-blotting. The main indicators (such as AST, ATL, and TBIL) of liver function and the volume of non-embolized hepatic lobes were measured in each group after operation. One-way ANOVA and Kruskal-wallis method were used for statistical analysis.

Results

The expression of MMP-2 mRNA and protein remained the highest in the Sham group, and the expression of MMP-2 mRNA and protein in TAE, PVE and TAE ​+ ​PVE groups were successively increased, and the expression of MMP-2 in TAE ​+ ​PVE group was always significantly higher than TAE group. The AST and ALT levels in each group on day 7 after operation showed a significant declination, and all groups have recovered to the preoperative baseline level and TBIL has a slight fluctuation in each group after operation with no statistical difference. On day 7 after operation, the increasing volume of non-embolized liver lobes in TAE ​+ ​PVE group showed a more significant effect than those in PVE group, but there was no statistical significance (37.62 ​± ​1.54 ​ml VS 36.18 ​± ​1.15 ​ml, P ​= ​0.881), and its volume was significantly higher than those in the sham group (27.03 ​± ​1.11 ​ml).

Conclusion

TAE ​+ ​PVE is considered to be an efficient and safe approach for treating rabbit VX2 liver transplantation tumor, but the expression of MMP-2 increased fastest after TAE ​+ ​PVE, which might promote tumor cell invasion and metastasis.

Primary Tumor Location Is a Prognostic Factor for Intrahepatic Progression-Free Survival in Patients with Colorectal Liver Metastases Undergoing Portal Vein Embolization as Preparation for Major Hepatic Surgery

The aim of this study was to identify prognostic factors affecting intrahepatic progression-free survival (ihPFS) and overall survival (OS) in patients with colorectal cancer liver metastases (CRCLM) undergoing portal vein embolization (PVE) and subsequent (extended) right hemihepatectomy. A total of 59 patients (mean age: 60.8 ± 9.3 years) with CRCLM who underwent PVE in preparation for right hemihepatectomy were included. IhPFS and OS after PVE were calculated using the Kaplan–Meier method. Cox regression analyses were conducted to investigate the association between the following factors and survival: patient age, laterality of the colorectal cancer (right- versus left-sided), tumor location (colon versus rectal cancer), time of occurrence of hepatic metastases (synchronous versus metachronous), baseline number and size of hepatic metastases, presence or absence of metastases in the future liver remnant (FLR) before PVE, preoperative carcinoembryogenic antigen (CEA) levels, time between PVE and surgery, history of neoadjuvant or adjuvant chemotherapy, and the presence or absence of extrahepatic disease before PVE. Median follow up was 18 months. The median ihPFS was 8.2 months (95% confidence interval: 6.2–10.2 months), and median OS was 34.1 months (95% confidence interval: 27.3–40.9 months). Laterality of the primary colorectal cancer was the only statistically significant predictor of ihPFS after PVE (hazard ratio (HR) = 2.242; 95% confidence interval: 1.125, 4.465; p = 0.022), with patients with right-sided colorectal cancer having significantly shorter median ihPFS than patients with left-sided cancer (4.0 ± 1.9 months versus 10.2 ± 1.5 months; log rank test: p = 0.018). Other factors, in particular also the presence or absence of additional metastases in the FLR, were not associated with intrahepatic progression-free survival. The presence of extrahepatic disease was associated with worse OS (HR = 3.050, 95% confidence interval: 1.247, 7.459; p = 0.015).

Correlation Between Sarcopenia and Growth Rate of the Future Liver Remnant After Portal Vein Embolization in Patients with Colorectal Liver Metastases

PURPOSE

To investigate whether sarcopenia and myosteatosis correlate with the degree of hypertrophy (DH) and kinetic growth rate (KiGR) of the future liver remnant (FLR) in patients with colorectal liver metastases undergoing portal vein embolization (PVE) in preparation for right hepatectomy.

MATERIALS AND METHODS

Forty-two patients were included. Total liver volume and FLR volume were measured before and 2-4 weeks after PVE. KiGR of the FLR was calculated. Sarcopenia was assessed using the total psoas muscle volume (PMV), the psoas muscle cross-sectional area (PMCS) and the total skeletal muscle index (L3SMI) at the level of 3rd lumbar vertebra. Degree of myosteatosis was assessed by mean muscle attenuation at L3 (L3MA). Correlations between muscle indices and DH and KiGR were assessed using simple linear regression analyses.

RESULTS

Mean DH was 8.9 ± 5.7%, and mean KiGR was 3.6 ± 2.3. Mean PMV was 55.56 ± 14.19 cm3/m3, mean PMCS was 8.76 ± 2.3 cm2/m2, mean L3SMI was 45.6 ± 9.89 cm2/m2, and mean L3MA was 27.9 ± 18.6 HU. There was a strong positive correlation between PMV and DH (R = 0.503, p = 0.001) and PMV and KiGR (R = 0.545, p < 0.001). Furthermore, there was a moderate correlation between PMCS and KiGR (R = 0.389, p = 0.014). L3SMI and L3MA were neither associated with DH (p = 0.390 and p = 0.768, respectively) nor with KiGR (p = 0.188 and p = 0.929, respectively).

CONCLUSION

We identified a positive correlation between PMV and PMCS, as markers for sarcopenia, and the KiGR of the FLR after PVE. PMV and PMCS might therefore aid to identify patients who are poor candidates for FLR augmentation using PVE alone.

Preparing for liver surgery with "Alphabet Soup": PVE, ALPPS, TAE-PVE, LVD and RL

Future liver remnant (FLR) size and function is a critical limiting factor for treatment eligibility and postoperative prognosis when considering surgical hepatectomy. Pre-operative portal vein embolization (PVE) has been proven effective in modulating FLR and now widely accepted as a standard of care. However, PVE is not always effective due to potentially inadequate augmentation of the FLR as well as tumor progression while awaiting liver growth. These concerns have prompted exploration of alternative techniques: associating liver partition and portal vein ligation for staged hepatectomy (ALPPS), transarterial embolization-portal vein embolization (TAE-PVE), liver venous deprivation (LVD), and radiation lobectomy (RL). The article aims to review the principles and applications of PVE and these newer hepatic regenerative techniques.

Current status of associating liver partition with portal vein ligation for staged hepatectomy: Comparison with two-stage hepatectomy and strategies for better outcomes

Since its introduction in 2012, associating liver partition with portal vein ligation for staged hepatectomy (ALPPS) has significantly expanded the pool of candidates for liver resection. It offers patients with insufficient liver function a chance of a cure. ALPPS is most controversial when its high morbidity and mortality is concerned. Operative mortality is usually a result of post-hepatectomy liver failure and can be minimized with careful patient selection. Elderly patients have limited reserve for tolerating the demanding operation. Patients with colorectal liver metastasis have normal liver and are ideal candidates. ALPPS for cholangiocarcinoma is technically challenging and associated with fair outcomes. Patients with hepatocellular carcinoma have chronic liver disease and limited parenchymal hypertrophy. However, in selected patients with limited hepatic fibrosis satisfactory outcomes have been produced. During the inter-stage period, serum bilirubin and creatinine level and presence of surgical complication predict mortality after stage II. Kinetic growth rate and hepatobiliary scintigraphy also guide the decision whether to postpone or omit stage II surgery. The outcomes of ALPPS have been improved by a combination of technical modifications. In patients with challenging anatomy, partial ALPPS potentially reduces morbidity, but remnant hypertrophy may compare unfavorably to a complete split. When compared to conventional two-stage hepatectomy with portal vein embolization or portal vein ligation, ALPPS offers a higher resection rate for colorectal liver metastasis without increased morbidity or mortality. While ALPPS has obvious theoretical oncological advantages over two-stage hepatectomy, the long-term outcomes are yet to be determined.

Is hepatectomy safe following Yttrium-90 therapy? A multi-institutional international experience

BACKGROUND

Single institution reports demonstrate variable safety profiles when liver-directed therapy with Yttrium-90 (Y-90) is followed by hepatectomy. We hypothesized that in well-selected patients, hepatectomy after Y90 is feasible and safe.

METHODS

Nine institutions contributed data for patients undergoing Y90 followed by hepatectomy (2008-2017). Clinicopathologic and perioperative data were analyzed, with 90-day morbidity and mortality as primary endpoints.

RESULTS

Forty-seven patients were included. Median age was 59 (20-75) and 62% were male. Malignancies treated included hepatocellular cancer (n = 14; 30%), colorectal cancer (n = 11; 23%), cholangiocarcinoma (n = 8; 17%), neuroendocrine (n = 8; 17%) and other tumors (n = 6). The distribution of Y-90 treatment was: right (n = 30; 64%), bilobar (n = 14; 30%), and left (n = 3; 6%). Median future liver remnant (FLR) following Y90 was 44% (30-78). Resections were primarily right (n = 16; 34%) and extended right (n = 14; 30%) hepatectomies. The median time to resection from Y90 was 196 days (13-947). The 90-day complication rate was 43% and mortality was 2%. Risk factors for Clavien-Dindo Grade>3 complications included: number of Y-90-treated lobes (OR 4.5; 95% CI1.14-17.7; p = 0.03), extent of surgery (p = 0.04) and operative time (p = 0.009).

CONCLUSIONS

These data demonstrate that hepatectomy following Y-90 is safe in well-selected populations. This multi-disciplinary treatment paradigm should be more widely studied, and potentially adopted, for patients with inadequate FLR.

How to increase the resectability of initially unresectable colorectal liver metastases: A surgical perspective

Although surgical resection is the only treatment of choice that can offer prolonged survival and a chance of cure in patients with colorectal liver metastases (CRLM), nearly 80% of patients are deemed to be unresectable at the time of diagnosis. Considerable efforts have been made to overcome this initial unresectability, including expanding the indication of surgery, the advent of conversion chemotherapy, and development and modification of specific surgical techniques, regulated under multidisciplinary approaches. In terms of specific surgical techniques, portal vein ligation/embolization can increase the volume of future liver remnant and thereby reduce the risk of hepatic insufficiency and death after major hepatectomy. For multiple bilobar CRLM that were traditionally considered unresectable even with preoperative chemotherapy and portal vein embolization, two-stage hepatectomy was introduced and has been adopted worldwide with acceptable short- and long-term outcomes. Recently, ALPPS (associating liver partition and portal vein ligation for staged hepatectomy) was reported as a novel variant of two-stage hepatectomy. Although issues regarding safety remain unresolved, rapid future liver remnant hypertrophy and subsequent shorter intervals between the two stages lead to a higher feasibility rate, reaching 98%. In addition, adding radiofrequency ablation and vascular resection and reconstruction techniques can allow expansion of the pool of patients with CRLM who are candidates for liver resection and thus a cure. In this review, we discuss specific techniques that may expand the criteria for resectability in patients with initially unresectable CRLM.

Long-Term Outcome After Conventional Two-Stage Hepatectomy Versus Tourniquet-ALPPS in Colorectal Liver Metastases: A Propensity Score Matching Analysis

BACKGROUND

To compare the overall survival (OS) and disease-free survival (DFS) of Tourniquet-ALPPS (T-ALPPS) and conventional two-stage hepatectomy (TSH) in patients with colorectal liver metastases (CRLM).

METHODS

A retrospective study from a prospectively collected database was performed between October 2000 and July 2016. TSH was performed before September 2011, after which time T-ALPPS became the technique of choice. A propensity score matching (PSM) was performed based on a 1:1 ratio with consideration of the following variables: number and size of metastases, bilobar disease presence, and chemotherapy received.

RESULTS

Thirty-four patients received T-ALPPS; 41 patients received TSH. After PSM, 21 patients remained in each group, with 100% resectability in the T-ALPPS group and 90.5% resectability in the TSH group. The median OS for TSH was 41 months; for T-ALPPS, the median OS was 36 months (P = 0.925). The median DFS was 16 months in the TSH group; the median DFS was 9 months in the T-ALPPS group (P = 0.930). The 1-, 3-, and 5-year OS for TSH was 81%, 66.7%, and 23.8% vs. 76.2%, 57.1%, and 22.9% for T-ALPPS, respectively. The 1-, 3-, and 5-year DFS for TSH was 66.7%, 9.5%, and 5% vs. 44.6%, 11.1%, and 11.1% for T-ALPPS, respectively. The volume increase with T-ALPPS was superior to that with TSH (68% vs. 39%; P = 0.018). There were no differences in morbidity and mortality after stages 1 and 2.

CONCLUSIONS

T-ALPPS produces a similar outcome to TSH, indicating that it could be a safe and effective alternative for curative hepatectomy for all patients.

Searching for the link; mechanisms underlying liver regeneration and recurrence of colorectal liver metastasis post partial hepatectomy

Despite excellent treatment of primary colorectal cancer, the majority of deaths occur as a result of metastasis to the liver. Recent population studies have estimated that one quarter of patients with colorectal cancer will incur synchronous or metachronous colorectal liver metastasis. However, only one quarter of these patients will be eligible for potentially curative resection. Tumor recurrence occurs in reportedly 60% of patients undergoing hepatic resection, and the majority of intrahepatic recurrence occurs within the first 6 months of surgery. The livers innate ability to restore its homeostatic size, and volume facilitates major hepatic resection that currently offers the only chance of cure to patients with extensive hepatic metastases. Experimental and clinical evidence supports the notion that following partial hepatectomy, liver regeneration (LR) paradoxically drives tumor progression and increases the risk of recurrence. It is becoming increasingly clear that the processes that drive liver organogenesis, regeneration, and tumor progression are inextricably linked. This presents a major hurdle in the management of colorectal liver metastasis and other hepatic malignancies because therapies that reduce the risk of recurrence without hampering LR are sought. The processes and pathways underlying these phenomena are multiple, complex, and cross-communicate. In this review, we will summarize the common mechanisms contributing to both LR and tumor recurrence.

Tourniquet-ALPPS is a promising treatment for very large hepatocellular carcinoma and intrahepatic cholangiocarcinoma

When very large hepatocellular carcinomas (HCCs) and intrahepatic cholangiocarcinoma (IHCCs) with insufficient future liver remnants are treated using associating liver partition and portal vein ligation for staged hepatectomy (ALPPS), the outcome is often poor. We therefore tested the efficacy of a modified version of that technique, tourniquet-ALPPS. A review of the literature examining outcomes of HCC and IHCC patients treated with ALPPS revealed the incidences of morbidity ≥ III and postoperative mortality to be respectively 20.7% and 16.1% among HCC patients and 50% and 45.4% among IHCC patients. In the present case series, in which HCC and IHCC patients were treated with tourniquet-ALPPS, median tumor size was 100 mm (range: 70-200 mm). After surgical stage I, there was no morbidity, no mortality and the median future liver remnant had increased at day 7 by 76%. In surgical stage II, 100% of tumors were resectable (8 right trisectionectomies, 5 with inferior vena cava resection). Two patients experienced serious morbidity ≥ IIIB and 1 patient died (11%). One- and 3-year overall survival was 75% and 60%, respectively. Thus tourniquet-ALPPS appears to be an effective alternative to classical ALPPS for the treatment of patients with HCC or IHCC.

Prospective study to determine early hypertrophy of the contra-lateral liver lobe after unilobar, Yttrium-90, selective internal radiation therapy in patients with hepatocellular carcinoma

BACKGROUND

Liver resection is a major curative option in patients presenting with hepatocellular carcinoma. An inadequate functional liver remnant is a major limiting factor precluding liver resection. In recent years, hypertrophy of the functional liver remnant after selective internal radiation therapy hypertrophy has been observed, but the degree of hypertrophy in the early postselective internal radiation therapy period has not been well studied.

METHODS

We conducted a prospective study on patients undergoing unilobar, Yttrium-90 selective internal radiation therapy for hepatocellular carcinoma to evaluate early hypertrophy at 4-6 weeks and 8-12 weeks after selective internal radiation therapy.

RESULTS

In the study, 24 eligible patients were recruited and had serial volumetric measurements performed. The median age was 66 years (38-75 years). All patients were either Child-Pugh Class A or B, and 6/24 patients had documented, clinically relevant portal hypertension; 15 of the 24 patients were hepatitis B positive. At 4-6 weeks, modest hypertrophy was seen (median 3%; range -12 to 42%) and this increased at 8-12 weeks (median 9%; range -12 to 179%). No preprocedural factors predictive of hypertrophy were identified.

CONCLUSION

Hypertrophy of the functional liver remnant after selective internal radiation therapy with Yttrium-90 occurred in a subset of patients but was modest and unpredictable in the early stages. Selective internal radiation therapy cannot be recommended as a standard treatment modality to induce early hypertrophy for patients with hepatocellular carcinoma. (Surgery 2017;160:XXX-XXX.).

Surgery-induced tumor growth in (metastatic) colorectal cancer

Metastatic colorectal cancer (mCRC) is a devastating disease causing 700.000 deaths annually worldwide. Metastases most frequently develop in the liver. Partial hepatectomy has dramatically improved clinical outcome and is the only curative treatment option for eligible patients with mCRC. Pre-clinical studies have shown that surgical procedures can have tumor-promoting local 'side-effects' such as hypoxia and inflammation, thereby altering the behaviour of residual tumor cells. In addition, systemically released factors following (colon or liver) surgery can act as a wakeup-call for dormant tumor cells in distant organs and/or help establish a pre-metastatic niche. Tumor handling during resection may also increase the number of circulating tumor cells. Despite the overwhelming amount of pre-clinical data demonstrating the pro-tumorigenic side effects of surgery, clinical evidence is scarce. Indications for hepatic surgery are rapidly increasing due to a rise in the incidence of mCRC and a trend towards more aggressive surgical treatment. Therefore, it is increasingly important to understand the principles of surgery-induced tumor growth, in order to devise perioperative or adjuvant strategies to further enhance long-term tumor control. In the current study we review the evidence for surgery-stimulated tumor growth and suggest strategies to assess the clinical relevance of such findings.

Next generation sequencing of progressive colorectal liver metastases after portal vein embolization

Portal vein embolization (PVE) can be required to stimulate liver regeneration before hepatectomy for colorectal liver metastasis (CRCLM), however PVE may also trigger CRCLM progression in patients initially exhibiting chemotherapy response. Using RNA-seq, we aimed to determine the molecular networks involved in metastatic progression in this context. A prospective study including all CRCLM patients undergoing PVE prior to hepatectomy was conducted. Paired biopsies of metastatic lesions were obtained prior to and after PVE and total RNA was isolated and used to prepare Illumina rRNA-depleted TruSeq stranded cDNA libraries for HiSeq 100 bp paired-end sequencing. Patients were classified with progression of disease (PD_PVE) or stable disease (SD_PVE) post-PVE using 3D-CT tumor volumetric analysis.

RESULTS

Twenty patients were included, 13 (65.0%) in the PD_PVE group (median 58.0% (18.6-234.3) increase in tumor volume) and 7 (35.0%) in the SD_PVE group exhibiting continuous chemotherapy response (median -14.3% (-40.8 to -2.8) decrease in tumor volume) (p < 0.0001). Our results showed that progressive CRCLM after PVE undergo gene expression changes that indicate activation of core cancer pathways (IL-17 (p = 5.94 × 10^-03), PI3K (p = 8.71 × 10^-03), IL6 and IGF-1 signaling pathways), consistent with changes driven by cytokines and growth factors. Differential expression analysis in a paired model of progression (EdgeR, DeSeq) identified significantly dysregulated genes in the PD_PVE group (FOS, FOSB, RAB20, IRS2).

CONCLUSION

Differentially expressed genes and pathways with known links to cancer and metastasis were identified post-PVE in patients with disease progression. Highlighting these molecular changes is a crucial first step towards development of targeted therapeutic strategies that may mitigate the effects of PVE on tumor growth.

Prognostic impact of type of preoperative biliary drainage in patients with distal cholangiocarcinoma

BACKGROUND

Surgical results of patients with resected distal cholangiocarcinoma (DCC) were evaluated to elucidate prognostic impact of the type of preoperative biliary drainage (PBD).

METHODS

Eighty-eight patients with resected DCC were stratified into two groups according to the type of PBD: the percutaneous transhepatic biliary drainage (PTBD) group (n = 25) and the endoscopic biliary drainage (EBD) group (n = 63).

RESULTS

Overall 5-year survival rate of the patients in the PTBD group was poorer than in the EBD group (24% vs. 52%, P = 0.020). On univariate analysis, PTBD, pancreatic invasion, perineural invasion, and lymph node involvement were significant prognostic factors for poor overall survival. On multivariate analysis, PTBD was the only significantly independent prognostic factor for poor overall survival. The incidence of liver metastasis was significantly higher in the PTBD group than in the EBD group (32.0% vs. 13.3%, P = 0.034).

CONCLUSIONS

PTBD should be avoided as much as possible in patients with DCC since the patients who underwent PTBD had poorer overall survival and higher incidence of liver metastasis than those who underwent EBD.

Factors associated with contralateral liver hypertrophy after unilateral radioembolization for hepatocellular carcinoma

INTRODUCTION

Radioembolization for the treatment of hepatocellular carcinoma (HCC) induces liver volume changes referred to as "atrophy-hypertrophy complex". The aim of this study was to investigate lobar liver volume changes after unilateral radioembolization and to search for factors associated with hypertrophy of the untreated lobe.

MATERIALS AND METHODS

Seventy-five patients were retrospectively evaluated. Inclusion criteria were: (1) right-lobar radioembolization for unresectable unilateral HCC, (2) available liver computed tomography scans before, 1, 3, and at least 6 months after radioembolization. Baseline patient characteristics included clinical features, laboratory results, spleen volume, and liver computed tomography. Absolute and relative (referred to the whole liver volume) liver lobe volumes (LLV) as well as relative LLV (rLLV) change per month were evaluated and compared.

RESULTS

Absolute and relative contralateral LLV continuously increased after radioembolization (p<0.001). Mean relative contralateral LLV increased from 36±11.6% before radioembolization to 50±15.3% 6 months after radioembolization. Median contralateral rLLV increase/month (within first 6 months) was 2.5%. Contralateral rLLV increase/month was significantly lower in patients with ascites (p = 0.017) or platelet count <100/nl (p = 0.009). An inverse correlation of contralateral rLVV increase/month with spleen volume (p = 0.017), patient age (p = 0.024), Child Pugh score (p = 0.001), and tumor burden (p = 0.001) was found.

CONCLUSIONS

Significant contralateral hypertrophy and ipsilateral atrophy were common after unilateral radioembolization. Small spleen volume, low patient age, low Child Pugh score, absence of ascites, platelet count ≥100/nl, and low tumor burden were associated with increased contralateral hypertrophy, indicating that younger patients with compensated cirrhosis might benefit most from radioembolization in a "bridge-to-resection" setting.

Systematic review of perioperative and survival outcomes of liver resections with and without preoperative portal vein embolization for colorectal metastases

BACKGROUND

The aim of this systematic review was to evaluate perioperative and long term outcomes in patients who underwent PVE prior to liver resection for colorectal liver metastases.

METHODS

A systematic search of PubMed, MEDLINE, Embase and the Cochrane library was performed in accordance with PRISMA guidelines. Studies including patients who underwent liver resection with and without PVE (N-PVE) were included.

RESULTS

Thirteen studies including 1345 were included of which 539 patients had PVE and 806 had N-PVE. Eight studies reported that from a total of 450 patients who underwent PVE, 136 (30%) did not proceed to liver resection. In 114 (84%) patients this was due to disease progression. The postoperative morbidity was 42% (n = 151) after PVE and 10% (n = 35) developed postoperative liver failure after liver resection. Median overall survival, reported in all studies, was 38.9 months and 45.6 months respectively, following resection with PVE and N-PVE. The median disease free survival, reported in eight studies, was 15.7 (PVE) and 21.4 (N-PVE) months respectively.

CONCLUSION

Following PVE 70% of patients proceed to liver resection, with a 10% risk of postoperative liver failure. Tumour progression after PVE was the predominant reason for not proceeding to liver resection.

Neoadjuvant transarterial radiation lobectomy for colorectal hepatic metastases: a small cohort analysis on safety, efficacy, and radiopathologic correlation

Colorectal cancer patients have a high incidence of liver metastasis (ml-CRC). Surgical resection is the gold standard for treatment of hepatic metastasis but only a small percent of patients are traditional candidates based on disease extent and adequate size of the future liver remnant (FLR). Interventions such as portal vein embolization (PVE) and associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) are performed to increase FLR for operative conversion. Limitations to PVE include intrahepatic disease progression, portal vascular invasion, and utilization with concurrent chemotherapy. ALPPS is associated with a high morbidly and mortality. Radiation lobectomy (RL) with yttrium-90 (Y-90) delivers transarterial ablative brachytherapy to the future hepatectomy site which generates FLR hypertrophy similar or greater than PVE. Early results indicate that RL is safe, effective, and may offer unique benefits by providing cytoreduction of hepatic metastases which extends FLR hypertrophy time and allows FLR surveillance to gauge disease biology. A retrospective analysis of four patients with ml-CRC treated with RL prior to hepatectomy was performed to evaluate initial safety, efficacy, FLR hypertrophy, and radiopathologic correlation. Adverse events after RL and hepatectomy were evaluated. Imaging findings were analyzed for efficacy defined as FLR hypertrophy and disease control. Radiopathologic correlation was performed after histologic analysis. RL was well tolerated without major adverse events or hepatic decompensation. FLR hypertrophy ranged from 24.9% to 119% at mean follow-up of three months. The majority of complications were related to surgical instrumentation of the FLR due to upstaging at time of surgery. Hepatectomy specimen histology demonstrated complete pathologic response in 50% of patients, 50% radiopathologic concordance rate, and no significant hepatic fibrosis. Initial experience with neoadjuvant RL for ml-CRC is safe and provides both durable disease control and FLR hypertrophy with concurrent chemotherapy. A 50% complete pathologic response rate raises the possibility of definitive chemoradiation in poor surgical candidates. Prospective investigation is required.

Current status and future perspectives on treatment of liver metastasis in colorectal cancer (Review)

Liver metastasis is the most common site of colorectal cancer (CRC) metastasis. Approximately half of all colorectal cancer patients will develop liver metastases. Although radical surgery is the standard treatment modality, only 10-20% of patients are deemed eligible for resection. Despite advances in survival with chemotherapy, surgical resection is still considered the only curative option for patients with liver metastases. Much effort has been expended to address patients with metastatic liver disease. The majority of evidence stated a significant survival benefit with surgical resection to reach an overall 5-year survival rate of 35-55% after hepatic resection. However, still majority of patients will experience disease recurrence even after a successful resection. In this review, we describe current status and controversies related to treatment options for CRC liver metastases and its potential for enhancing oncologic outcomes and improving quality of life.

Ablative Liver Partition and Portal Vein Embolization: Proof-of-Concept Testing in a Rabbit Model

PURPOSE

To test the hypothesis that a modified approach to portal vein embolization (PVE)-termed ablative liver partition (ALP) and PVE (ALP-PVE)-is feasible and results in greater future liver remnant (FLR) growth compared with PVE alone in a rabbit model.

MATERIALS AND METHODS

Eighteen rabbits (median weight, 2.7 kg) underwent PVE (n = 9) or ALP-PVE (n = 9). PVE to cranial liver lobes was performed with 100-300-μm microspheres and metallic coils; the caudal lobe was spared as the FLR. In the ALP-PVE cohort, a liver partition between cranial and caudal lobes was created by using microwave ablation (40 W, 1 min). Animals were euthanized and livers were harvested on postprocedure day 7. Caudal and cranial liver lobes were weighed after 4 weeks of oven drying. Ki-67 immunohistochemistry was used to quantify liver mitotic index. ALP-PVE feasibility was determined based on procedure technical success. Standardized FLR (sFLR; ie, FLR divided by whole liver weight) and mitotic index were compared between PVE and ALP-PVE groups by two-tailed independent-samples Mann-Whitney U test.

RESULTS

One PVE-group rabbit died during anesthesia induction and was excluded from technical success calculation. Eight of 8 (100%) and 8 of 9 rabbits (89%) underwent technically successful PVE and ALP-PVE, respectively. There was no difference in sex or weight distribution between groups. sFLR (0.32 vs 0.29; P = .022) and mitotic index (17.5% vs 6.2%; P = .051) were higher in ALP-PVE vs PVE caudal lobes when the first "learning-curve" case from each group was excluded.

CONCLUSIONS

ALP-PVE is feasible and may stimulate greater FLR growth compared with PVE in a rabbit model.

ALPPS (associating liver partition and portal vein ligation for staged hepatectomy) does not affect proliferation, apoptosis, or angiogenesis as compared to standard liver resection for colorectal liver metastases

Background

ALPPS (associating liver partition and portal vein ligation for staged hepatectomy) is a novel two-stage strategy to induce rapid hypertrophy of the future liver remnant (FLR) when patients are in danger of postoperative liver failure due to insufficient FLR. However, the effects of ALPPS on colorectal liver metastases (CRLM) are not clear so far. The aim of our study was to determine whether ALPPS induces proliferation, apoptosis, or vascularization compared to standard (one-stage) liver resection.

Methods

Six patients who underwent ALPPS were matched with 12 patients undergoing standard liver resection regarding characteristics of the metastases (size, number), time of appearance (syn-/metachronous), preoperative chemotherapy, primary tumor (localization, TNM stage, grading), and patient variables (gender, age). The largest resected metastasis was used for the analyses. Tissue was stained for tumor cell proliferation (Ki67), apoptosis (TUNEL, caspase-3), vascularization (CD31), and pericytes (αSMA).

Results

Vascularization (CD31; p = 0.149), proliferation (Mib-1; p = 0.244), and αSMA expression (p = 0.205) did not significantly differ between the two groups, although a trend towards less proliferation and αSMA expression was observed in patients undergoing ALPPS. Concerning apoptosis, caspase-3 staining showed significantly fewer apoptotic cells upon ALPPS (p < 0.0001), but this was not confirmed by TUNEL staining (p = 0.7344).

Conclusions

ALPPS does not induce proliferation, apoptosis, or vascularization of CRLM when compared to standard liver resection.

Surgical Implications of Portal Vein Variations and Liver Segmentations: A Recent Update

The Couinaud's liver segmentation is based on the identification of portal vein bifurcation and origin of hepatic veins. It is widely used clinically, because it is better suited for surgery and is more accurate in localizing and monitoring various intra parenchymal lesions. According to standard anatomy, the portal vein bifurcates into right and left branches; the left vein drains segment II, III and IV and the right vein divides into two secondary branches - the anterior portal vein drains segments V and VIII, and the posterior drains segments VI and VII. The portal vein variants such as portal trifurcation, with division of the main portal vein into the left, right anterior, and posterior branches, and the early origin of the right posterior branch directly from the main portal vein were found to be more frequent and was seen in about 20 - 35% of the population. Accurate knowledge of the portal variants and consequent variations in vascular segments are essential for intervention radiologists and transplant surgeons in the proper diagnosis during radiological investigations and in therapeutic applications such as preparation for biopsy, Portal Vein Embolization (PVE), Transjugular Intrahepatic Porto-Systemic Shunt (TIPS), tumour resection and partial hepatectomy for split or living donor transplantations. The advances in the knowledge will reduce intra and postoperative complications and avoid major catastrophic events. The purpose of the present review is to update the normal and variant portal venous anatomy and their implications in the liver segmentations, complex liver surgeries and various radiological intervention procedures.

Treating hepatocellular carcinoma with 90Y-bearing microspheres: a review

Hepatocellular carcinoma (HCC) is a disease usually diagnosed in its advanced-stage, and is frequently not amenable to curative surgical treatment. Also, HCC is resistant to chemotherapy and less vulnerable to radiation therapy compared to normal hepatic parenchyma. Both of these facts render the efficacy of adjuvant and palliative treatments problematic. Selective internal radiation therapy (SIRT) with ⁹⁰Y-bearing microspheres is characterized by preferentially delivering substantially high doses of radiation to a liver tumor dose simultaneously limiting the damage to its non-tumorous cells, providing an opportunity for effective local tumor control and even tumor regression therapy. The current article reviews the specific characters, dosimetry, possible applications, and special considerations toward the pre-existing radiation therapy of ⁹⁰Y microsphere SIRT in treating HCC.