Neoadjuvant chemotherapy does not impair liver regeneration following hepatectomy or portal vein embolization for colorectal cancer liver metastases

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

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

Extended Right Hepatectomy following Clearance of the Left Liver Lobe and Portal Vein Embolization for Curatively Intended Treatment of Extensive Bilobar Colorectal Liver Metastases: A Single-Center Case Series

BACKGROUND

Two-staged hepatectomy (TSH) including portal vein embolization (PVE) may offer surgical treatment for extensive bilobar colorectal liver metastases (CRLM). This study aimed to investigate the feasibility and outcomes of extended right hepatectomy (ERH) within TSH including PVE for patients with extended CRLM.

METHODS

We retrospectively collected data of patients who underwent TSH for extended CRLM between 2015 and 2021 at our institution. Clearance of the left liver lobe (clear-up, CU) associated with PVE was followed by ERH.

RESULTS

Minimally invasive (n = 12, 46%, MIH) or open hepatectomy (n = 14, 54%, OH) was performed. Postoperative major morbidity and 90-day mortality were 54% and 0%. Three-year overall survival was 95%. Baseline characteristics, postoperative and long-term outcomes were comparable between MIH and OH. However, hospital stay was significantly shorter after MIH (8 vs. 15 days, p = 0.008). Additionally, the need for intraoperative transfusions tended to be lower in the MIH group (17% vs. 50%, p = 0.110).

CONCLUSIONS

ERH following CU and PVE for extended CRLM is feasible and safe in laparoscopic and open approaches. MIH for ERH may result in shorter postoperative hospital stays. Further high-volume, multicenter studies are required to evaluate the potential superiority of MIH.

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.

Impact of neoadjuvant chemotherapy on post-hepatectomy regeneration for patients with colorectal cancer liver metastasis - Systematic review and meta-analysis

BACKGROUND

Today, there is still debate on the impact of neoadjuvant chemotherapy (NeoChem) on liver regeneration (LivReg). The objectives of this study were to assess the impact of NeoChem and its characteristics (addition of bevacizumab, number of cycles and time from end of NeoChem) on post-hepatectomy LivReg.

MATERIAL & METHODS

Studies reporting LivReg in patients submitted to liver resection were included. Pubmed, Scopus, Web of Science, Embase, and Cochrane databases were searched. Only studies comparing NeoChem vs no chemotherapy or comparing chemotherapy characteristics from 1990 to present were included. Two researchers individually screened the identified records registered in a predesigned database. Primary outcome was future liver remnant regeneration rate (FLR3). Bias of the studies was evaluated with the ROBINS-I tool, and quality of evidence with the GRADE system. Data was presented as mean difference or standard mean difference.

RESULTS

Eight studies with a total of 681 patients were selected. Seven were retrospective and one prospective comparative cohort studies. In patients submitted to major hepatectomy, NeoChem did not have an impact on LivReg (MD 3.12, 95% CI -2,12-8.36, p 0,24). Adding bevacizumab to standard NeoChem was associated with better FLR3 (SMD 0.45, 95% CI 0.19-0.71, p 0.0006).

DISCUSSION

The main drawback of this review is the retrospective nature of the available studies. NeoChem does not have a negative impact on postoperative LivReg in patients submitted to liver resection. Regimens with bevacizumab seem to be associated with better postoperative LivReg rates when compared to standard NeoChem.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

The evolution of surgery for colorectal liver metastases: A persistent challenge to improve survival

Only a few decades ago, the opinion that colorectal liver metastases were a palliative diagnosis changed. In fact, previously, the prevailing view was strongly resistant against resecting colorectal liver metastases. Constant technical improvement of liver surgery and, much later, effective chemotherapy allowed for a successful wider application of surgery. The clinical use of portal vein embolization was the starting signal of regenerative liver surgery, where insufficient liver volume can be expanded to an extent where safe resection is possible. Today, a number of these techniques including portal vein ligation, associating liver partition and portal vein ligation for staged hepatectomy, and bi-embolization (portal and hepatic vein) can be successfully used to address an insufficient future liver remnant in staged resections. It turned out that the road to success is embedding surgery in a well-orchestrated oncological concept of controlling systemic disease. This concept was the prerequisite that meant liver transplantation could enter the treatment strategy for colorectal liver metastases, ending up with a 5-year overall survival of 80% in highly selected cases. In particular, techniques combining principles of 2-stage hepatectomy and liver transplantation, such as "resection and partial liver segment 2-3 transplantation with delayed total hepatectomy" (RAPID) are on the rise. These techniques enable the use of partial liver grafts with primarily insufficient liver volume. All this progress also prompted a number of innovative local therapies to address recurrences ultimately transferring colorectal liver metastases from instantly deadly into a chronic disease in some cases.

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

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

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

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

The effect of preoperative chemotherapy on liver regeneration after portal vein embolization/ligation or liver resection in patients with colorectal liver metastasis: a systematic review protocol

INTRODUCTION

Liver resection (LR) in patients with liver metastasis from colorectal cancer remains the only curative treatment. Perioperative chemotherapy improves prognosis of these patients. However, there are concerns regarding the effect of preoperative chemotherapy on liver regeneration, which is a key event in avoiding liver failure after LR. The primary objective of this systematic review is to assess the effect of neoadjuvant chemotherapy on liver regeneration after (LR) or portal vein embolization (PVE) in patients with liver metastasis from colorectal cancer. The secondary objectives are to evaluate the impact of the type of chemotherapy, number of cycles, and time between end of treatment and procedure (LR or PVE) and to investigate whether there is an association between degree of hypertrophy and postoperative liver failure.

METHODS

This meta-analysis will include studies reporting liver regeneration rates in patients submitted to LR or PVE. Pubmed, Scopus, Web of Science, Embase, and Cochrane databases will be searched. Only studies comparing neoadjuvant vs no chemotherapy, or comparing chemotherapy characteristics (bevacizumab administration, number of cycles, and time from finishing chemotherapy until intervention), will be included. We will select studies from 1990 to present. Two researchers will individually screen the identified records, according to a list of inclusion and exclusion criteria. Primary outcome will be future liver remnant regeneration rate. Bias of the studies will be evaluated with the ROBINS-I tool, and quality of evidence for all outcomes will be determined with the GRADE system. The data will be registered in a predesigned database. If selected studies are sufficiently homogeneous, we will perform a meta-analysis of reported results. In the event of a substantial heterogeneity, a qualitative systematic review will be performed.

DISCUSSION

The results of this systematic review may help to better identify the patients affected by liver metastasis that could present low regeneration rates after neoadjuvant chemotherapy. These patients are at risk to develop liver failure after extended hepatectomies and therefore are not good candidates for such aggressive procedures.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number: CRD42020178481 (July 5, 2020).

Interventional Oncology Approach to Hepatic Metastases

Metastatic liver disease is one of the major causes of cancer-related morbidity and mortality. Locoregional therapies offered by interventional oncologists alleviate cancer-related morbidity and in some cases improve survival. Locoregional therapies are often palliative in nature but occasionally can be used with curative intent. This review will discuss important factors to consider prior to palliative and curative intent treatment of metastatic liver disease with locoregional therapy. These factors include those specific to the tumor, liver function, liver reserve, differences between treatment modalities, and patient-specific considerations.

Splenic enlargement induced by preoperative chemotherapy is a useful indicator for predicting liver regeneration after resection for colorectal liver metastases

Background

Conversion chemotherapy may downsize unresectable colorectal liver metastases (CRLMs), but may cause liver injury and splenic enlargement. The effect of preoperative chemotherapy on liver regeneration after liver resection remains undetermined. The aim of this study was to examine whether splenic enlargement induced by preoperative chemotherapy is an indicator to identify high-risk patients for impaired liver regeneration and liver dysfunction after resection.

Methods

We retrospectively reviewed 118 Japanese patients with CRLMs. Fifty-one patients had conversion chemotherapy. The other 67 patients underwent up-front liver resection. We clarified effects of conversion chemotherapy on splenic volume, liver function, and postoperative liver regeneration. Perioperative outcome was also analyzed.

Results

A ratio of the splenic volume before and after chemotherapy (SP index) in the oxaliplatin-based chemotherapy group was significantly greater than other chemotherapy groups after 9 or more chemotherapy cycles. Patients whose SP index was 1.2 or more had significantly higher indocyanine green retention rate at 15 min (ICG-R15) than patients without chemotherapy. Analyses of covariance showed liver regeneration rate after resection was decreased in patients whose SP index was 1.2 or more. The incidence of postoperative liver dysfunction in patients whose SP index was 1.2 or more was significantly greater than patients without chemotherapy. Multivariate analysis showed SP index was a significant predictive factor of impaired liver regeneration.

Conclusions

Splenic enlargement induced by preoperative chemotherapy was a useful indicator for impaired liver regeneration after resection and a decision-making tool of treatment strategy for unresectable CRLMs.

Population-based study on practice variation regarding preoperative systemic chemotherapy in patients with colorectal liver metastases and impact on short-term outcomes

INTRODUCTION

Definitions regarding resectability and hence indications for preoperative chemotherapy vary. Use of preoperative chemotherapy may influence postoperative outcomes. This study aimed to assess the variation in use of preoperative chemotherapy for CRLM and related postoperative outcomes in the Netherlands.

MATERIALS AND METHODS

All patients who underwent liver resection for CRLM in the Netherlands between 2014 and 2018 were included from a national database. Case-mix factors contributing to the use of preoperative chemotherapy, hospital variation and postoperative outcomes were assessed using multivariable logistic regression. Postoperative outcomes were postoperative complicated course (PCC), 30-day morbidity and 30-day mortality.

RESULTS

In total, 4469 patients were included of whom 1314 patients received preoperative chemotherapy and 3155 patients did not. Patients receiving chemotherapy were significantly younger (mean age (+SD) 66.3 (10.4) versus 63.2 (10.2) p < 0.001) and had less comorbidity (Charlson scores 2+ (24% versus 29%, p = 0.010). Unadjusted hospital variation concerning administration of preoperative chemotherapy ranged between 2% and 55%. After adjusting for case-mix factors, three hospitals administered significantly more preoperative chemotherapy than expected and six administered significantly less preoperative chemotherapy than expected. PCC was 12.1%, 30-day morbidity was 8.8% and 30-day mortality was 1.5%. No association between preoperative chemotherapy and PCC (OR 1.24, 0.98-1.55, p = 0.065), 30-day morbidity (OR 1.05, 0.81-1.39, p = 0.703) or with 30-day mortality (OR 1.22, 0.75-2.09, p = 0.467) was found.

CONCLUSION

Significant hospital variation in the use of preoperative chemotherapy for CRLM was present in the Netherlands. No association between postoperative outcomes and use of preoperative chemotherapy was found.

Therapeutic targets for liver regeneration after acute severe injury: a preclinical overview

Introduction: Liver transplantation is the only viable treatment with a proven survival benefit for acute liver failure (ALF). Donor organ shortage is, however, a major hurdle; hence, alternative approaches that enable liver regeneration and target acute severe hepatocellular damage are necessary.Areas covered: This article sheds light on therapeutic targets for liver regeneration and considers their therapeutic potential. ALF following extensive hepatocyte damage and small-for-size syndrome (SFSS) are illuminated for the reader while the molecular mechanisms of liver regeneration are assessed in accordance with relevant therapeutic strategies. Furthermore, liver background parameters and predictive biomarkers that might associate with liver regeneration are reviewed.Expert opinion: There are established and novel experimental strategies for liver regeneration to prevent ALF resulting from SFSS. Granulocyte-colony stimulating factor (G-CSF) is a promising agent targeting liver regeneration after acute severe injury. Autophagy and hepatocyte senescence represent attractive new targets for liver regeneration in acute severe hepatic injury. Liver support strategies, including tissue engineering, constitute novel regenerative means; the success of this is dependent on stem cell research advances. However, there is no firm clinical evidence that these supportive strategies may alleviate hepatocellular damage until liver transplantation becomes available or successful self-liver regeneration occurs.

Future Liver Remnant Hypertrophy after Portal Vein Embolization Is Inversely Correlated with Intrahepatic Tumor Burden

PURPOSE

To determine if there is a correlation between intrahepatic tumor volume and future liver remnant (FLR) hypertrophy after portal vein embolization (PVE).

MATERIALS AND METHODS

Forty-four consecutive patients with hepatocellular carcinoma or metastatic colorectal cancer who underwent PVE from 2009 to 2017 and who had complete imaging follow-up were retrospectively reviewed. To maximize the accuracy of tumor volume measurements, 11 patients were excluded for having more than 5 intrahepatic tumors. Volumetric analyses of the patient livers before and after PVE, as well as pre-embolization intrahepatic tumor burden, were performed.

RESULTS

A significant inverse correlation was observed between tumor volume and FLR hypertrophy after PVE (Spearman ρ = -0.53, P = .002). Initial FLR volume was also inversely correlated with subsequent hypertrophy (P = .01). Fourteen patients received neoadjuvant chemotherapy 1 month prior to intervention. The number of chemotherapy cycles did not affect hypertrophy (P = .57). Patients with cirrhosis experienced less FLR hypertrophy than patients without cirrhosis (P = .02).

CONCLUSIONS

Patients with large intrahepatic tumor burden may experience limited FLR hypertrophy.

Repeat procedures for recurrent colorectal liver metastases: analysis of long-term liver regeneration and outcome

Background and aim: Repeat hepatectomy is increasingly performed for the management of recurrent colorectal liver metastases (CRLM). The aim of this study was to evaluate long-term functional liver volume (FLV) after a second hepatic procedure and to measure survival outcome. Methods: In this retrospective cohort study, patients treated for recurrent CRLM in the years 2005-2015 at two liver centers were included. Total FLV was calculated before the first procedure and before and after the second procedure. Overall survival was calculated. Results: Eighty-two patients were identified. The median follow-up was 53 (40-71) months from the first procedure. The median interval between first and second procedure was 13 (8-22) months. The initial FLV was 1584 (1313-1927) mL. The FLV was 1438 (1204-1896) mL after the first procedure and 1470 (1172-1699) mL after the second procedure (P<0.001). After the second procedure, a total of ten patients (12%) had a residual liver volume of less than 75% of the initial liver volume. The 5-year overall survival was 37 (26-54)% after the second procedure. Conclusion: Small changes in FLV were found after two hepatic procedures but with considerable inter-individual variation. Patients selected for a repeated hepatic procedure for recurrent CRLM had an acceptable survival.

Segment 2/3 Hypertrophy is Greater When Right Portal Vein Embolisation is Extended to Segment 4 in Patients with Colorectal Liver Metastases: A Retrospective Cohort Study

Background

In patients with colorectal cancer liver metastases (CRLM), right portal vein embolisation (RPVE) is used to increase the volume of the future remnant liver (FRL) before major hepatic resection. It is not established whether embolisation of segment 4 in addition RPVE (RPVE + 4) induces greater hypertrophy of the FRL. Limitations of prior studies include heterogenous populations and use of hypertrophy metrics sensitive to baseline variables.

Methods

From 2010 to 2015, consecutive patients undergoing RPVE or RPVE + 4 for CRLM, who had not undergone prior major hepatic resection and in whom imaging was available, were included in a retrospective study. Data were extracted from hospital electronic records. Volumetric assessments of segments 2–3 were made on cross-sectional imaging before and after embolisation and corrected for standardised liver volume.

Results

Ninety-nine patients underwent PVE, and 60 met the inclusion criteria. Thirty-eight patients underwent RPVE, and 22 underwent RPVE + 4. Forty-five patients had undergone median 6 cycles of prior chemotherapy. Eighteen patients had FRL metastases at PVE, and 16 had undergone subsegmental metastasectomy in the FRL. Assessments of the degree of hypertrophy (DH) of segments 2/3 were made at median 35 (interquartile range 30–49) days after PVE. RPVE + 4 resulted in a significantly greater increase in DH than RPVE (7.7 ± 1.8% vs 11.3 ± 2.6%, p = 0.011). No confounding association between baseline variables and the decision to undertake RPVE or RPVE + 4 was identified. Median survival was 2.4 years and was not influenced by segment 4 embolisation.

Conclusion

RPVE + 4 results in greater DH of segments 2/3 than RPVE in people with CLRM.

Functional and volumetric assessment of liver segments after portal vein embolization: Differences in hypertrophy response

BACKGROUND

Patients considered for liver resection with insufficient volume or function of the future remnant liver are candidates for portal vein embolization to allow safe resection. The aim of this study is to analyze the volumetric and functional responses after portal vein embolization and to evaluate predictors of the hypertrophy response.

METHODS

All patients who underwent portal vein embolization before liver resection 2006-2017 were included. Patients who did not undergo computed tomography-volumetry and functional assessment with technetium-99m mebrofenin hepatobiliary scintigraphy before and after portal vein embolization were excluded. The functional and volumetric response rates were calculated. Multiple regression analysis was conducted to examine the relationship between the hypertrophy response and potential predictors.

RESULTS

A total of 90 patients underwent portal vein embolization of the right liver. After 3 weeks, there was a significant increase in both volumetric and functional share of the future remnant liver (both P < .01). The increase in functional share exceeded the increase in volumetric share (P < .01). The median functional contribution of segment 4 after portal vein embolization was 41.5% (31.7%-48.7%) of the nonembolized lobe. Preoperative chemotherapy was not a significant predictor of the increase in function or volume. Compared with benign lesions, malignant diseases were significant negative predictors of the functional response.

CONCLUSION

A total of 3 weeks after portal vein embolization, the functional response exceeded that of the volumetric response, meaning that the waiting time to resection potentially can be decreased. Segment 4 had a significant share of both volume and function, enabling surgical strategies only leaving segment 4 as a monosegment. Neoadjuvant chemotherapy had no negative influence on the hypertrophy response.

Current status of surgical treatment of colorectal liver metastases

Liver metastasis (LM) is one of the major causes of death in patients with colorectal cancer (CRC). Approximately 60% of CRC patients develop LM during the course of their illness. About 85% of these patients have unresectable disease at the time of presentation. Surgical resection is currently the only curative treatment for patients with colorectal LM (CRLM). In recent years, with the help of modern multimodality therapy including systemic chemotherapy, radiation therapy, and surgery, the outcomes of CRLM treatment have significantly improved. This article summarizes the current status of surgical treatment of CRLM including evaluation of resectability, treatment for resectable LM, conversion therapy and liver transplantation for unresectable cases, liver resection for recurrent CRLM and elderly patients, and surgery for concomitant hepatic and extra-hepatic metastatic disease (EHMD). We believe that with the help of modern multimodality therapy, an aggressive oncosurgical approach should be implemented as it has the possibility of achieving a cure, even when EHMD is present in patients with CRLM.

Assessment and optimization of liver volume before major hepatic resection: Current guidelines and a narrative review

Post hepatectomy liver failure (PHLF) remains a significant cause of morbidity and mortality after major liver resection. Although the etiology of PHLF is multifactorial, an inadequate functional liver remnant (FLR) is felt to be the most important modifiable predictor of PHLF. Pre-operative evaluation of FLR function and volume is of paramount importance before proceeding with any major liver resection. Patients with inadequate or borderline FLR volume must be considered for volume optimization strategies such as portal vein embolization (PVE), two stage hepatectomy with portal vein ligation (PVL), Yttrium-90 radioembolization, and associating liver partition and portal vein ligation for staged hepatectomy (ALPPS). This paper provides an overview of assessing FLR volume and function, and discusses indications and outcomes of commonly used volume optimization strategies.

Portal Vein Embolization Reduces Postoperative Hepatic Insufficiency Associated with Postchemotherapy Hepatic Atrophy

BACKGROUND

The risk of postoperative hepatic insufficiency (PHI) is increased among patients with significant postchemotherapy hepatic atrophy. The primary aim of this study was to evaluate whether the liver regeneration stimulated by portal vein embolization (PVE) can protect against PHI.

METHODS

Clinicopathological features of 177 patients treated with preoperative chemotherapy followed by PVE and hepatectomy were reviewed. Degree of atrophy was defined as the ratio of percentage difference in total liver volume (estimated by manual volumetry) to standardized liver volume. Kinetic growth rate (KGR, degree of hypertrophy [absolute % change in future liver remnant volume] divided by the number of weeks after PVE) and PHI events were compared between patients with degree of atrophy <10 vs ≥10%. Risk factors for the PHI were assessed using logistic regression.

RESULTS

Seventy patients (40%) experienced significant hepatic atrophy ≥10% following preoperative chemotherapy. PHI rates were not significantly increased in patients who experienced significant hepatic atrophy (5.6 vs 8.6%, P = 0.443). KGR <2%/week (odds ratio, 8.10, P = 0.037) was the sole independent preoperative predictor of PHI. KGR ≥2% was associated with decreased PHI in both patients with <10% atrophy (0 vs 9.5%, P = 0.035) and ≥10% atrophy (2.6 vs 16.0%, P = 0.044).

CONCLUSIONS

Even in high-risk patients with ≥10% degree of atrophy from preoperative chemotherapy, KGR ≥2% mitigates the deleterious effects of hepatic atrophy and significantly reduces PHI to almost zero. In these high-risk patients, PVE with KGR calculation remains the most important preoperative technique to reduce liver failure after major hepatectomy.

Hepatic atrophy following preoperative chemotherapy predicts hepatic insufficiency after resection of colorectal liver metastases

BACKGROUND & AIMS

For patients with colorectal liver metastases (CLM) undergoing major hepatectomy, extensive preoperative chemotherapy has been associated with increased morbidity and mortality. The impact of extensive chemotherapy on total liver volume (TLV) change is unclear. The aims of the current study were twofold: (1) to determine the change of TLV following preoperative chemotherapy in patients undergoing resection for CLM and (2) to investigate the correlations among TLV change, postoperative hepatic insufficiency (PHI), and death from liver failure.

METHODS

Clinicopathological features of patients with CLM who underwent preoperative chemotherapy and curative resection were reviewed (2008-2015). TLV change (degree of atrophy) was defined as the percentage difference of TLV (estimated by manual volumetry)/standardized liver volume (SLV) ratio: ([Pre-chemotherapy TLV]-[Post-chemotherapy TLV])×100÷SLV (%). Receiver operating characteristic (ROC) analysis was performed to decide the accurate cut-off value of degree of atrophy to predict PHI. The Cox proportional hazard model was performed to identify the predictors of severe degree of atrophy and PHI.

RESULTS

The study cohort consisted of 459 patients, of which 154 patients (34%) underwent extensive preoperative chemotherapy (≥7 cycles). ROC analysis identified the degree of atrophy ≥10% as an accurate cut-off to predict PHI, which was significantly correlated with ≥7 cycles of preoperative chemotherapy. Four factors independently predicted PHI: standardized future liver remnant ≤30% (odds ratio [OR] 4.03, p=0.019), high aspartate aminotransferase-to-platelet ratio index (OR 5.27, p=0.028), degree of atrophy ≥10% (OR 43.5, p<0.001), and major hepatic resection (OR 5.78, p=0.005). Degree of atrophy ≥10% was associated with increased mortality from liver failure (0% [0/374] vs. 15% [13/85], p<0.001).

CONCLUSION

Extensive preoperative chemotherapy induced significant atrophic change of TLV. Degree of atrophy ≥10% is an independent predictor of PHI and death in patients with CLM undergoing preoperative chemotherapy and resection.

LAY SUMMARY

Extensive preoperative chemotherapy for patients with colorectal liver metastases (CLM) could induce hepatic atrophy. A higher degree of atrophy is an independent predictor of postoperative hepatic insufficiency and death in patients with CLM undergoing preoperative chemotherapy and resection.

Effect of non-alcoholic liver disease on recurrence rate and liver regeneration after liver resection for colorectal liver metastases

BACKGROUND

Resection of metastases is the only potential cure for patients with liver metastasis from colorectal cancer (crc-lm). But despite an improved overall 5-year survival, the recurrence rate is still as high as 60%. Non-alcoholic fatty liver disease (nafld) can decrease the liver's capacity to regenerate after resection and might also affect cancer recurrence, potentially by elevating transforming growth factor β, levels of specific metalloproteinases, and oxidative stress. The objective of the present work was to determine the effect of the histologic features of nafld on cancer recurrence and liver regeneration.

METHODS

This retrospective analysis considered 60 patients who underwent an R0 hepatectomy for crc-lm. Volumetric analysis of the liver was calculated using axial view, portovenous phase, 2.5 mm thickness, multiphasic computed tomography images taken before and after surgery. The histologic features of nafld (steatosis, inflammation, and ballooning) were scored using the nafld activity score, and the degree of fibrosis was determined.

RESULTS

The hepatic recurrence rate was 38.33%. Median overall survival duration was 56 months. Median disease-free survival duration was 14 months, and median hepatic disease-free survival duration was 56 months. Multivariate analysis revealed significant correlations of hepatic disease-free survival with hepatocyte ballooning (p = 0.0009), lesion diameter (p = 0.014), and synchronous disease (p = 0.006). Univariate and multivariate analyses did not reveal any correlation with degree of steatosis or recurrence rate.

CONCLUSIONS

This study reveals an important potential negative effect of hepatocyte ballooning on hepatic disease-free survival.

Hepatotoxicity following systemic therapy for colorectal liver metastases and the impact of chemotherapy-associated liver injury on outcomes after curative liver resection

Patients with colorectal liver metastases (CLM) have remarkably benefited from the advances in medical multimodal treatment and surgical techniques over the last two decades leading to significant improvements in long-term survival. More patients are currently undergoing liver resection following neoadjuvant chemotherapy, which has been increasingly established within the framework of curative-indented treatment strategies. However, the use of several cytotoxic agents has been linked to specific liver injuries that not only impair the ability of liver tissue to regenerate but also decrease long-term survival. One of the most common agents included in modern chemotherapy regimens is oxaliplatin, which is considered to induce a parenchymal damage of the liver primarily involving the sinusoids defined as sinusoidal obstruction syndrome (SOS). Administration of bevacizumab, an inhibitor of vascular endothelial growth factor (VEGF), has been reported to improve response of CLM to chemotherapy in clinical studies, concomitantly protecting the liver from the development of SOS. In this review, we aim to summarize current data on multimodal treatment concepts for CLM, give an in-depth overview of liver damage caused by cytostatic agents focusing on oxaliplatin-induced SOS, and evaluate the role of bevacizumab to improve clinical outcomes of patients with CLM and to protect the liver from the development of SOS.

[Portal vein embolization: Present and future]

Portal vein embolization consists of occluding a part of the portal venous system in order to achieve the hypertrophy of the non-embolized liver segments. This technique is used during the preoperative period of major liver resection when the future remnant liver (FRL) volume is insufficient, exposing to postoperative liver failure, main cause of death after major hepatectomy. Portal vein embolization indication depends on the FRL, commonly assessed by its volume. Nowadays, FRL function evaluation seems more relevant and can be measured by 99mTc labelled mebrofenin scintigraphy. Portal vein embolization procedure is mostly performed with percutaneous trans-hepatic access by using ultrasonography guidance and consists of embolic agent injection, such as cyanoacrylate, in the targeted portal vein branches with fluoroscopic guidance. It is a safe and well-tolerated technique, with extremely low morbi-mortality. Portal vein embolization leads to sufficient FRL hypertrophy in about 80% of patients, allowing them to undergo surgery from which they were initially rejected. The two main reasons of non-resection are tumor progression (≈15% of cases) and FRL insufficient hypertrophy (≈5% of cases). When portal vein embolization is not enough to obtain adequate FRL regeneration, hepatic vein embolization may potentiate its effect (liver venous deprivation technique).

Portal vein embolization for induction of selective hepatic hypertrophy prior to major hepatectomy: rationale, techniques, outcomes and future directions

The ability to modulate the future liver remnant (FLR) is a key component of modern oncologic hepatobiliary surgery practice and has extended surgical candidacy for patients who may have been previously thought unable to survive liver resection. Multiple techniques have been developed to augment the FLR including portal vein embolization (PVE), associating liver partition and portal vein ligation (ALPPS), and the recently reported transhepatic liver venous deprivation (LVD). PVE is a well-established means to improve the safety of liver resection by redirecting blood flow to the FLR in an effort to selectively hypertrophy and ultimately improve functional reserve of the FLR. This article discusses the current practice of PVE with focus on summarizing the large number of published reports from which outcomes based practices have been developed. Both technical aspects of PVE including volumetry, approaches, and embolization agents; and clinical aspects of PVE including data supporting indications, and its role in conjunction with chemotherapy and transarterial embolization will be highlighted. PVE remains an important aspect of oncologic care; in large part due to the substantial foundation of information available demonstrating its clear clinical benefit for hepatic resection candidates with small anticipated FLRs.