Application of preoperative portal vein embolization before major hepatic resection in patients with normal or abnormal liver parenchyma

Role of Preoperative Hepatobiliary Scintigraphy in Children Requiring Liver Resection

PURPOSE

The risk of posthepatectomy liver failure (PHLF) remains an important concern following major liver resection. Assessment of future remnant liver function (FRLF) by hepatobiliary scintigraphy has shown its significance to prevent PHLF after major liver resection in adults with a threshold value of FRLF greater than 2.7%/min per m2. However, such data for pediatric patients were not published.

METHODS

A total of 77 pediatric patients with liver tumors who underwent 1-stage liver resection were included in this study. Assessment of FRLF, future remnant liver volume (FRLV), and the ratio of remnant liver volume to body weight (RLV-BWR) was performed before the surgery.

RESULTS

All patients had RLV-BWR values of more than 0.5%/kg. Future remnant liver volume values ranged from 19% to 89%, and FRLF values ranged from 1.8% to 31.8%/min per m2. Only 7 of 77 patients had FRLV values less than 25%, but their FRLF values exceeded 2.7%/min per m2. Two patients developed grade A and grade B PHLF.

CONCLUSION

Future remnant liver volume and the RLV-BWR can be used in most pediatric patients for the assessment of liver before hepatectomy. According to our data, implementation of FRLF assessment using hepatobiliary scintigraphy can be most beneficial for children with FRLV of less than 25%. The cutoff value of FRLV greater than 25% can be slightly decreased with minimal risk of developing PHLF. However, to establish a new cutoff value for FRLV in children, further prospective studies including larger numbers of patients with FRLV of less than 25% are needed.

Protocol for the CoNoR Study: A prospective multi-step study of the potential added benefit of two novel assessment tools in colorectal liver metastases technical resectability decision-making

INTRODUCTION

Liver resection is the only curative treatment for colorectal liver metastases (CLM). Resectability decision-making is therefore a key determinant of outcomes. Wide variation has been demonstrated in resectability decision-making, despite the existence of criteria. This paper summarises a study protocol to evaluate the potential added value of two novel assessment tools in assessing CLM technical resectability: the Hepatica preoperative MR scan (MR-based volumetry, Couinaud segmentation, liver tissue characteristics and operative planning tool) and the LiMAx test (hepatic functional capacity).

METHODS AND ANALYSIS

This study uses a systematic multistep approach, whereby three preparatory workstreams aid the design of the final international case-based scenario survey:Workstream 1: systematic literature review of published resectability criteria.Workstream 2: international hepatopancreatobiliary (HPB) interviews.Workstream 3: international HPB questionnaire.Workstream 4: international HPB case-based scenario survey.The primary outcome measures are change in resectability decision-making and change in planned operative strategy, resulting from the novel test results. Secondary outcome measures are variability in CLM resectability decision-making and opinions on the role for novel tools.

ETHICS AND DISSEMINATION

The study protocol has been approved by a National Health Service Research Ethics Committee and registered with the Health Research Authority. Dissemination will be via international and national conferences. Manuscripts will be published.

REGISTRATION DETAILS

The CoNoR Study is registered with ClinicalTrials.gov (registration number NCT04270851). The systematic review is registered on the PROSPERO database (registration number CRD42019136748).

Increased future liver function after modified associating liver partition and portal vein ligation/embolization for staged hepatectomy

Background

The increasing ratio of functional future liver remnant (functional %FLR) after modified associating liver partition and portal vein ligation/embolization for staged hepatectomy (modified-ALPPS) compared with portal vein embolization (PVE) has not been comprehensively evaluated.

Purpose

To compare the increasing ratio of functional %FLR between modified-ALPPS and PVE via technetium-99 m-galactosyl human serum albumin single-photon emission computed tomography (^99mTc-GSA SPECT/CT) fusion imaging.

Material and Methods

Seven and six patients underwent modified-ALPPS (modified-ALPPS group) and PVE (PVE group) from 2015 to 2019. The functional %FLR on 99 mTc-GSA SPECT/CT fusion imaging was assessed before and 1 week (modified-ALPPS group) and 3 weeks (PVE group) after each procedure. The increasing ratio of functional %FLR (functional %FLR ratio) was calculated and compared between the two groups. Moreover, the hypertrophy ratio of future liver remnant volume (FLRV ratio) and atrophy ratio of embolized liver volume (.ELV ratio) were evaluated.

Results

The mean functional %FLR ratios of the modified-ALPPS group (1.47 ± 0.15) and the PVE group (1.49 ± 0.20) were comparable (p > .05). The median FLRV ratio of modified-ALPPS group (1.48) was higher than that of the PVE group (1.16), the median ELV ratio of the PVE group (0.81) was lower than that of the modified-ALPPS group (0.94), and the results significantly differed between the two groups (p < .05).

Conclusion

The increasing ratio of functional %FLR was comparable between modified-ALPPS and PVE. Compared with PVE, ALPPS was associated with a higher hypertrophy rate of the remnant liver but a lower atrophy rate of the embolized liver.

Safety and efficacy of right portal vein embolization in patients with prior left lateral liver resection

BACKGROUND

In patients with bilobar metastatic liver disease, surgical clearance of both liver lobes may be achieved through multiple-stage liver resections. For patients with extensive disease, a major two-staged hepatectomy consisting of resection of liver segments II and III before right-sided portal vein embolization (PVE) and resection of segments V-VIII may be performed, leaving only segments IV ± I as the liver remnant.

PURPOSE

To describe the outcome following right-sided PVE after prior complete resection of liver segments II and III.

MATERIAL AND METHODS

In this retrospective study, 15 patients (mean age = 60.4 ± 9.3 years) with liver metastases from colorectal cancer (n = 14) and uveal melanoma (n = 1) who were scheduled to undergo a major two-stage hepatectomy, were included. Total liver volume (TLV) and volume of the future liver remnant (FLR) were measured on pre- and postinterventional computed tomography (CT) scans, and standardized FLR volumes (ratio FLR/TLV) were calculated. Patient data were retrospectively analyzed regarding peri- and postinterventional complications, with special emphasis on liver function tests.

RESULTS

The mean standardized post-PVE FLR volume was 26.9% ± 6.4% and no patient developed hepatic insufficiency after the PVE. Based on FLR hypertrophy and liver function tests, all but one patient were considered eligible for the subsequent right-sided hepatectomy. However, due to local tumor progression, only 9/15 patients eventually proceeded to the second stage of surgery.  .

CONCLUSION

Right-sided PVE was safe and efficacious in this cohort of patients who had previously undergone a complete resection of liver segments II and III as part of a major staged hepatectomy pathway leaving only segments IV(±I) as the FLR. .

Living Donor Liver Transplantation as a Backup Procedure: Treatment Strategy for Hepatocellular Adenomas Requiring Complex Resections

Background & Aims. The most dangerous complications of hepatocellular adenomas are hemorrhage and malignant transformation, both of which require surgical treatment. The surgical treatment strategy for patients with benign large or central tumors is challenging because complex liver resections are required. The strategy of using a live donor as a backup procedure is described in this series. Methods. We present a series of three patients with large hepatocellular adenoma lesions showing a central location, for which the living donor liver transplantation strategy was used as a backup procedure. Results. Hepatocellular adenoma was confirmed by biopsy in all patients. Surgical resection was indicated because of the patients’ symptoms and lesion size and growth. All patients had a lesion that was central or in close contact with major vessels. The final decision to proceed with the resection was made intraoperatively. A live donor was prepared for all three patients. Two patients underwent portal vein embolization associated with extended hepatectomy, and a total hepatectomy plus liver transplantation with a living donor was performed in one patient. All patients had good postoperative outcomes. Conclusions. In the treatment of hepatocellular adenomas for which complex resections are necessary and resectability can only be confirmed intraoperatively, surgical safety can be improved through the use of a living donor backup. Center expertise with living donor liver transplantation is paramount for the success of this approach.

[Analysis of future liver remnant parameters in children after extended liver resection]

OBJECTIVE

To analyze the initial data on future liver remnant volume and its function evaluated by ^99mTc-Bromesida hepatobiliary scintigraphy in children with liver tumors.

MATERIAL AND METHODS

Extended liver resections were performed in 58 patients aged 2 months - 208 months (median 26 months) for various neoplasms. Before hepatectomy, all children underwent contrast-enhanced CT with volumetry and hepatobiliary scintigraphy with ^99mTc-Bromezida and subsequent quantitative assessment of its accumulation in the future liver remnant. All consecutive patients eligible for extended liver resection were retrospectively analyzed.

RESULTS

The analysis included patients who underwent extended liver resection between June 2017 and March 2021. Among 91 liver resections, 58 (64%) procedures were extended hepatectomies including 2 ALPPS procedures. Median volume of future liver remnant was 44.5% (16.5-91.4), median future liver remnant function - 10.14%/min/m² (1.8-30). Four patients with adequate liver function had insufficient volume of future liver remnant. Insufficient future liver remnant volume and its appropriate function were observed in 2 patients. Not life-threatening post-resection liver failure developed in 2 patients.

CONCLUSION

Evaluation of future liver remnant function is the most sensitive method to predict post-hepatectomy liver failure in children. The cut off value of future liver remnant volume in children is below 25% and probably below 16.5%. Further data collection and research are warranted to determine significant values. These data will contribute to define the new indications for two-staged hepatectomies in children.

Current status of laparoscopic hepatectomy for the treatment of hepatocellular carcinoma: A systematic literature review

BACKGROUND

Laparoscopic hepatectomy (LH) was first introduced in the 1990s and has now become widely accepted for the treatment of hepatocellular carcinoma (HCC). Laparoscopic liver resection (LLR) is considered a safe and effective approach for liver disease. However, the role of laparoscopic hepatectomy in HCC with cirrhosis remains controversial and needs to be further assessed, and the present literature review aimed to review the surgical and oncological outcomes of Laparoscopic hepatectomy (LH). According to Hong and colleagues laparoscopic resection for liver cirrhosis is a very safe and feasible procedure for both ideal cases and select patients with high risk factors [29]. The presence of only 1 of these factors does not represent an absolute contraindication for LH.

METHODS AND RESULTS

We selected 23 studies involving about 1363 HCC patients treated with LH. 364 (27%) patients experienced major resections. The mean operative time was 244.9 minutes, the mean blood loss was 308.1 mL and blood transfusions were required in only 4.9% of patients. There were only 2 (0.21%) postoperative deaths and overall morbidity was 9.9%. Tumor recurrence ranged from 6 to 25 months. The 1-year, 3-year, and 5-year disease free Survival (DFS) rates ranged from 71.9% to 99%, 50.3% to 91.2%, and 19% to 82% respectively. Overall survival rates ranged from 88% to 100%, 73.4% to 94.5%, and 52.6% to 94.5% respectively.

CONCLUSIONS

In our summery LH is lower risk and safer than conventional open liver surgery and is just as efficacious. Also, the LH approach decreased blood-loss, operation time, postoperative morbidity and had a lower conversion rate compared to other procedures whether open or robotic. Finally, LH may serve as a promising alternative to open procedures.

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).

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

KEY POINTS

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

Prospective study of change in liver function and fat in patients with colorectal liver metastases undergoing preoperative chemotherapy: protocol for the CLiFF Study

INTRODUCTION

Preoperative chemotherapy in patients undergoing resection for colorectal liver metastases (CLM) improves oncological outcomes. However, chemotherapy-associated liver injury (occurring in two patterns: vascular and fat deposition) is a real clinical concern prior to hepatic resection. After major liver resection, regeneration of the residual liver is a prerequisite for recovery and avoidance of liver failure, but this regenerative capacity may be hindered by chemotherapy. Thus, there is a need to predict for this serious complication. Over the past two decades, several tests and derived indices have been developed, which have failed to achieve clinical utility, mainly as they were indirect measurements of liver function. Here, we will use a novel test of liver function (the liver maximum capacity (LiMAx) test), and measure liver fat using MRI.

METHODS AND ANALYSIS

This prospective study will assess changes in liver function longitudinally, measured by the LiMAx test, and liver fat, measured by advanced MRI using both MR spectroscopy and the modified Dixon method, in up to 35 patients undergoing preoperative chemotherapy for CLM. The primary outcomes will be the changes in liver function and fat compared with baseline prechemotherapy measurements. Secondary outcome measures include: routinely measured liver function blood tests, anthropometric measurements, postoperative histology and digital quantification of fat, postoperative complications and mortality and quality of life.

ETHICS AND DISSEMINATION

The study was approved by a National Health Service Research Ethics Committee and registered with the Health Research Authority. Dissemination will be via international and national conferences and the National Institute for Health Research network. Manuscripts will be published.

TRIAL REGISTRATION NUMBER

This study is registered online at www.clinicaltrials.gov (registration number NCT03562234).

Combined biembolization induces higher hypertrophy than portal vein embolization before major liver resection

BACKGROUND

Combined preoperative portal and hepatic vein embolization (biembolization, BE) has been recently described and may further enhance preoperative FLR growth. The objective of this study was to compare the efficacy of combined preoperative biembolization and portal vein embolization (PVE).

METHODS

This study was performed between 2010 and 2017. From 2010 to 2014, patients only underwent preoperative PVE. After 2014, BE was proposed as an alternative to PVE. Liver volumetry was assessed by a CT-scan before BE or PVE and then three weeks later.

RESULTS

During the study period, 72 patients underwent radiological procedures that included 41 PVE (PVE group) and 31 BE (BE group). The time elapsing between the procedure and surgery was similar (p = 0.760). The mean percentage of FLR ratio hypertrophy in the PVE group was 31.9% (±34), but reached 51.2% (±42) in the BE group (p = 0.018) and this difference remained significant under multivariate analysis that included age, gender, body mass index, diabetes mellitus, cirrhosis and NASH. The kinetic growth rates were 19% (±17%) and 8% (±13%) in the BE and PVE groups, respectively (p = 0.026).

CONCLUSION

This study shows that BE induces higher hypertrophy than portal vein embolization before major liver resection with no more morbidity.

Assessment of remnant liver function and volume after selective ligation of portal vein and hepatic artery in a rat model

Purpose:

To evaluate liver regeneration after selective ligation of portal vein and hepatic artery by 3D Computed Tomography in an experimental model.

Methods:

Sixteen Wistar rats were randomized into four equal groups: Group I- control (sham), Group II- isolated selective ligation of the hepatic artery, Group III- isolated selective ligation of the portal vein and Group IV- combined ligation of portal vein and hepatic artery. Before procedure and five days after a 3D CT Scan was performed to analyze the hypertrophy, weight and function of the remnant liver.

Results:

The largest regeneration rate and increase of weight in the hypertrophied lobe was detected in group IV, the first with an average of 3.99 (p=0.006) and the last varying from 6.10g to 9.64g (p=0.01). However, total liver weight and the R1 ratio (Hypertrophied Lobe Weight/Total Liver Weight) was higher in group III (P<0.001) when compared with groups I, II and IV and showed no difference between them. The immunohistochemical examination with PCNA also found higher percentages with statistical significance differences in rats of groups III and IV. It was possible to confirm a strong correlation between hypertrophied lobe weight and its imaging volumetric study. Liver function tests only showed a significant difference in serum gamma-glutamyltransferase and phosphorous.

Conclusion:

There is a largest liver regeneration after combined ligation of portal vein and hepatic artery and this evidence may improve the knowledge of surgical treatment of liver injuries, with a translational impact in anima nobile.

Portal Vein Embolization: Radiological Findings Predicting Future Liver Remnant Hypertrophy

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

Dilatation of left portal vein after right portal vein embolization: a simple estimation for growth of future liver remnant

BACKGROUND

To evaluate correlation between growth rate of left portal vein (LPV) and future liver remnant (FLR) after right portal vein embolization (PVE), and to design models predicting FLR growth rate and volume using LPV area measurements on computed tomography (CT).

METHODS

A total of 134 patients (59.6 ± 10.2 years; 103 men) who underwent right PVE with contrast-enhanced CT before and 3-5 weeks after PVE were retrospectively identified. Kinetic hypertrophy ratio (KHR) and kinetic degree of hypertrophy (KDH) served as growth rate parameters. Correlations between LPV growth rate and FLR growth rate and volume change were evaluated by linear regression analysis. The agreements between actual volumetrically determined growth rates and volume of FLR and those estimated from regression equation using LPV measurements were assessed by Bland-Altman plots.

RESULTS

Growth rates of LPV and FLR correlated significantly (P < 0.001). The mean difference between actual and estimated value was 0.1% for KHR-FLR (actual, 9.5 ± 6.0%; estimated, 9.4 ± 3.8%), 0.0% for KDH-FLR (actual, 3.3 ± 1.4%; estimated, 3.3 ± 0.7%), -3.8 cm³ for FLR volume (actual, 642.5 ± 167.8 cm³ ; estimated, 646.4 ± 156.5 cm³ ), and -0.1% for proportion of FLR volume (actual, 48.7 ± 7.8%; estimated, 48.9 ± 7.8%).

CONCLUSIONS

After right PVE, FLR growth rate and volume can be simply estimated from the change in LPV area.

Perioperative and long-term outcomes of laparoscopic versus open liver resection for hepatocellular carcinoma with well-preserved liver function and cirrhotic background: a propensity score matching study

BACKGROUND

Although laparoscopic liver resection (LLR) has advanced into a safe and effective alternative to conventional open liver resection (OLR), it has not been widely accepted by surgeons. This article aimed to investigate the perioperative and long-term benefits of LLR versus OLR for hepatocellular carcinoma (HCC) in selected patients with well-preserved liver function and cirrhotic background.

METHODS

A retrospective study was conducted on 1085 patients with HCC who underwent liver resection at Sun Yat-Sen Memorial Hospital of Sun Yat-Sen University from July 2010 to July 2015, and 346 patients with well-preserved liver function and cirrhotic background were selected. A 1:1 propensity score matching (PSM), which is the best option to overcome selection bias, was conducted to compare the surgical outcomes and long-term prognosis between LLR and OLR. After PSM, a logistic regression analysis was used to identify the predictive risk factors of posthepatectomy liver failure (PHLF).

RESULTS

By using PSM, the two groups were well balanced with 86 patients in each group. In the LLR group, only the median operation time was significantly longer than the OLR group, but the hospital stay, overall morbidity, and the incidence of PHLF were significantly decreased compared to OLR. There were no significant differences in the overall survival and disease-free survival rates between the two groups. On multivariate analysis, OLR was identified to be the only independent risk factor for PHLF.

CONCLUSIONS

In selected HCC patients with well-preserved liver function and cirrhotic background, LLR could be a better option compared to OLR.

Meta-analysis of associating liver partition with portal vein ligation and portal vein occlusion for two-stage hepatectomy

BACKGROUND

Discussion is ongoing regarding whether associating liver partition with portal vein ligation for staged hepatectomy (ALPPS) or portal vein occlusion is better in staged hepatectomy. The aim of this study was to compare available strategies using a two-stage approach in extended hepatectomy.

METHODS

A literature search was performed in MEDLINE, Scopus, the Cochrane Library and Embase, and additional articles were identified by hand searching. Data from the international ALPPS registry were extracted. Clinical studies reporting volumetric changes, mortality, morbidity, feasibility of the second stage and tumour-free resection margins (R0) in two-stage hepatectomy were included.

RESULTS

Ninety studies involving 4352 patients, including 320 from the ALPPS registry, met the inclusion criteria. Among these, nine studies (357 patients) reported on comparisons with other strategies. In the comparison of ALPPS versus portal vein embolization (PVE), ALPPS was associated with a greater increase in the future liver remnant (76 versus 37 per cent; P < 0·001) and more frequent completion of stage 2 (100 versus 77 per cent; P < 0·001). Compared with PVE, ALPPS had a trend towards higher morbidity (73 versus 59 per cent; P = 0·16) and mortality (14 versus 7 per cent; P = 0·19) after stage 2. In the non-comparative studies, complication rates were 39 per cent in the PVE group, 47 per cent in the portal vein ligation (PVL) group and 70 per cent in the ALPPS group. After stage 2, mortality rates were 5, 7 and 12 per cent respectively.

CONCLUSION

ALPPS is associated with greater future liver remnant hypertrophy and a higher rate of completion of stage 2, but this may be at the price of greater morbidity and mortality.

Analysis of Portal Vein Embolization Using Absolute Ethanol Before Major Hepatectomy

Portal vein embolization (PVE) is widely considered to improve the safety and extend the indication of major hepatectomy. There are various embolization materials and techniques in each facility. The safety and efficacy of absolute ethanol (EOH) in PVE were analyzed. Fifty-one patients who underwent PVE prior to major hepatectomy were enrolled in this study. Two types of embolization techniques were performed: transileocolic portal vein embolization (TIPE) and percutaneous transhepatic portal vein embolization (PTPE). The embolization material consisted of 20 mL of EOH and 2 mL of iodized oil. Multislice computed tomography (CT) scans were performed before and after PVE. The mean time interval between PVE and the follow-up CT scan was 16.3 ± 5.0 days. The mean future liver remnant ratio to total liver (FLR%) significantly increased from 32.1% ± 7.6% to 43.5% ± 9.5% after PVE (P &lt; 0.001). The mean hypertrophy ratio was 41.1% ± 34.5%. There were 3 major complications, subcutaneous hematoma in the TIPE group, hemobilia, and bile leakage in the PTPE group. Although the levels of aspartate transaminase and alanine transaminase increased dramatically after PVE, they subsequently returned to pre-PVE levels. There were no patients whose liver dysfunction was prolonged until hepatectomy. In conclusion, PVE using EOH is a safe and effective method to induce hypertrophy in the future remnant liver before major hepatectomy.

Portal vein embolization using absolute ethanol: evaluation of its safety and efficacy

BACKGROUND

Previously, we reported on the clinical efficacy and safety of portal vein embolization (PVE) with fibrin glue. Our embolic materials for PVE changed from fibrin glue to absolute ethanol (EOH) after 2001 due to prohibition of using fibrin glue for PVE. With introducing our technique of PVE with EOH, we evaluated its safety and efficacy with attention to the amount of EOH.

METHODS

The medical records of 154 patients who underwent PVE using EOH were retrospectively reviewed.

RESULTS

Changes with time in both the serum levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) after PVE returned to the initial condition within 7 days after PVE. In the 96 patients who underwent CT volumerty 14 to 21 days after PVE, the volume of the embolized lobe decreased from 701 ± 165 cm(3) to 549 ± 148 cm(3) (P < 0.0001). Meanwhile, the volume of the non-embolized lobe increased from 388 ± 105 cm(3) to 481 ± 113 cm(3) (P < 0.0001). On simple linear regression, the amount of EOH was positively correlated with both the maximum of AST and that of ALT after PVE; however, it never correlated with changes in liver volume after PVE.

CONCLUSIONS

Portal vein embolization with EOH has a substantial effect on both hypertrophy of the non-embolized lobe and atrophy of the embolized lobe. Quick recoveries of changes with time in AST and ALT after PVE proved that PVE with EOH is a safe procedure. The amount of EOH affected the extent of liver damage but had no clinical effects on changes in liver volume after PVE.

Systematic review of pathophysiological changes following hepatic resection

OBJECTIVES

Major hepatic resection is now performed frequently and with relative safety, but is accompanied by significant pathophysiological changes. The aim of this review is to describe these changes along with interventions that may help reduce the risk for adverse outcomes after major hepatic resection.

METHODS

The MEDLINE, EMBASE and CENTRAL databases were searched for relevant literature published from January 2000 to December 2011. Broad subject headings were 'hepatectomy/', 'liver function/', 'liver failure/' and 'physiology/'.

RESULTS

Predictable changes in blood biochemistry and coagulation occur following major hepatic resection and alterations from the expected path indicate a complicated course. Susceptibility to sepsis, functional renal impairment, and altered energy metabolism are important sequelae of post-resection liver failure.

CONCLUSIONS

The pathophysiology of post-resection liver failure is difficult to reverse and thus strategies aimed at prevention are key to reducing morbidity and mortality after liver surgery.

Portal vein embolization and ligation for extended hepatectomy

Portal vein occlusion through embolization or ligation (PVE, PVL) offers the possibility of increasing the future liver remnant (FLR) and thus reducing the risk of hepatic failure after extended hepatectomy We reviewed the indications, scope and applicability of PVE/PVL in treatment of primary and secondary liver tumours. A thorough PubMED, Embase, Ovid and Cochrane database search was carried out for all original articles with 30 patients or more undergoing either PVE and any patient series with PVL, irrespective of number with outcome measure in at least one of the following parameters: FLR volume change, complications, length of stay, time to surgery, proportion resectable and survival data. PVE can be performed with a technical success in 98.9 % (95 % confidence interval 97-100) patients, with a mean morbidity of 3.13 % (95 % CI 1.21-5.04) and a median in-hospital stay of 2.1 (range 1-4) days (very few papers had data on length of stay following PVE). The mean increase in volume of the FLR following PVE was 39.75 % (95 % CI 30.8-48.6) facilitating extended liver resection after a mean of 37.13 days (95 % CI 28.51-45.74) with a resectability rate of 76.88 % (95 % CI 70.91-82.84). Morbidity and mortality following such extended liver resections after PVE is 26.58 % (95 % CI 19.20-33.95) and 2.59 % (95 % CI 1.34-3.83) respectively with an in-patient stay of 13.57 days (95 % CI 9.8-17.37). However following post-PVE liver hypertrophy 6.29 % (95 % CI 2.24-10.34) patients still have post-resection liver failure and up to 14.2 % (95 % CI -8.7 to 37) may have positive resection margins. Up to 4.80 % (95 % CI 2.07-7.52) have failure of hypertrophy after PVE and 17.46 % (95 % CI 11.89-23.02) may have disease progression during the interim awaiting hypertrophy and subsequent resection. PVL has a greater morbidity and duration of stay of 5.72 % (95 % CI 0-15.28) and 10.16 days (95 % CI 6.63-13.69) respectively; as compared to PVE. Duration to surgery following PVL was greater at 53.6 days (95 % CI 32.14-75.05). PVL induced FLR hypertrophy by a mean of 64.65 % (95 % CI 0-136.12) giving a resectability rate of 63.68 % (95 % CI 56.82-70.54). PVL failed to produce enough liver hypertrophy in 7.4 % of patients (95 % CI 0-16.12). Progression of disease following PVL was 29.29 (95%CI 15.69-42.88). PVE facilitates an extended hepatectomy in patients with limited or inadequate FLR, with good short and long-term outcomes. Patients need to be adequately counselled and consented for PVE and EH in light of these data. PVL would promote hypertrophy as well, but clearly PVE has advantages as compared to PVL on account of its inherent "minimally invasive" nature, fewer complications, length of stay and its feasibility to have shorter times to surgery.

A predictive factor of insufficient liver regeneration after preoperative portal vein embolization

BACKGROUND

Preoperative portal vein embolization (PVE) is performed to enhance the future remnant liver function (FRLF) and volume (FRLV). However, the volume of the nonembolized liver does not increase enough in some patients, which results in an insufficient FRLF. The aim of this study was to evaluate the predictors of insufficient FRLF after PVE for extended hepatectomy.

METHODS

This retrospective study included 172 patients (107 patients with cholangiocarcinoma, 40 patients with metastatic liver cancer and 25 patients with hepatocellular carcinoma) who underwent PVE before extended hepatectomy. The total liver function was evaluated by measuring the indocyanine green plasma clearance rate (KICG). Computed tomography volumetry was conducted to evaluate the total liver volume and FRLV. The KICG of the future remnant liver (remK) was calculated using the following formula: KICG × FRLV/total liver volume. The safety margin for hepatectomy was set at remK after PVE (post-PVE remK) ≥ 0.05.

RESULTS

One hundred and twenty-three patients with a post-PVE remK level of >0.05 underwent hepatectomy without postoperative liver failure [sufficient liver regeneration (SLR) group], and 9 patients with a post-PVE remK level of <0.05 did not due to insufficient FRLF [insufficient liver regeneration (ILR) group]. In the SLR group, the KICG values did not change after PVE (median, 0.144-0.146, p = 0.523); however, the %FRLV and remK increased significantly (35.0-44.3%, p < 0.001 and 0.0488-0.0610, p < 0001, respectively). In contrast, in the ILR group, the KICG values decreased significantly (0.128-0.108, p = 0.021) and the %FRLV increased marginally (27.4-32.6%, p = 0.051). As a result, the remK did not increase significantly (0.0351-0.0365, p = 0.213). A receiver operating characteristic curve demonstrated an remK value of 0.04 obtained before PVE (pre-PVE remK) to be the optimal cutoff point for defective liver regeneration. The univariate and multivariate analyses revealed that a pre-PVE remK value of <0.04 was a factor for ILR. It was also correlated with postoperative liver failure in the analysis of the patients who underwent hepatectomy.

CONCLUSIONS

The patients in the ILR group did not achieve SLR after PVE due to a significant decrease in the KICG and an insufficient increase in %FRLV. A pre-PVE remK value of <0.04 is a useful predictor of insufficient regeneration of the nonembolized liver, even after PVE.

Increase in left liver lobe function after preoperative right portal vein embolisation assessed with gadolinium-EOB-DTPA MRI

OBJECTIVES

To prospectively evaluate the early development of regional liver function after right portal vein embolisation (PVE) with Gd-EOB-DTPA-enhanced MRI in patients scheduled for extended right hemihepatectomy.

METHODS

Ten patients who received a PVE before an extended hemihepatectomy were examined before and 14 days after PVE using Gd-EOB-DTPA-enhanced MRI of the liver. In these sequences representative region of interest measurements were performed in the embolised right (RLL) and the non-embolised left liver lobe (LLL). The volume as well as hepatic uptake index (HUI) was calculated independently for each lobe.

RESULTS

Relative enhancement 14 days after PVE decreased in the RLL and increased significantly in the LLL (P < 0.05). Average hepatic uptake index (HUI) for RLL was significantly lower 14 days after PVE than before PVE (P < 0.05) and significantly higher for LLL (P < 0.05).

CONCLUSIONS

A significant shift of contrast uptake from the right to the left liver lobe can be depicted as early as 14 days after right PVE by using Gd-EOB-DTPA-enhanced MRI, which could reflect the redirected portal venous blood flow and the rapid utilisation of a hepatic functional reserve.

KEY POINTS

• Preoperative portal vein embolisation (PVE) is widely performed before right-sided hepatic resection. • PVE increases intravenous contrast medium uptake in the left lobe of liver. • The hepatic uptake index for the left liver lobe increases rapidly after PVE. • Left liver lobe function increase may be visualised by Gd-EOB-DTPA-enhanced MRI.

Kinetic growth rate after portal vein embolization predicts posthepatectomy outcomes: toward zero liver-related mortality in patients with colorectal liver metastases and small future liver remnant

BACKGROUND

Standardized future liver remnant (sFLR) volume and degree of hypertrophy after portal vein embolization (PVE) have been recognized as important predictors of surgical outcomes after major liver resection. However, the regeneration rate of the FLR after PVE varies among individuals and its clinical significance is unknown.

STUDY DESIGN

Kinetic growth rate (KGR) is defined as the degree of hypertrophy at initial volume assessment divided by number of weeks elapsed after PVE. In 107 consecutive patients who underwent liver resection for colorectal liver metastases with an sFLR volume >20%, the ability of the KGR to predict overall and liver-specific postoperative morbidity and mortality was compared with sFLR volume and degree of hypertrophy.

RESULTS

Using receiver operating characteristic analysis, the best cutoff values for sFLR volume, degree of hypertrophy, and KGR for predicting postoperative hepatic insufficiency were estimated as 29.6%, 7.5%, and 2.0% per week, respectively. Among these, KGR was the most accurate predictor (area under the curve 0.830 [95% CI, 0.736-0.923]; asymptotic significance, 0.002). A KGR of <2% per week vs ≥2% per week correlates with rates of hepatic insufficiency (21.6% vs 0%; p = 0.0001) and liver-related 90-day mortality (8.1% vs 0%; p = 0.04). The predictive value of KGR was not influenced by sFLR volume or the timing of initial volume assessment when evaluated within 8 weeks after PVE.

CONCLUSIONS

Kinetic growth rate is a better predictor of postoperative morbidity and mortality after liver resection for small FLR than conventional measured volume parameters (ie, sFLR volume and degree of hypertrophy).

Multimodal management of colorectal liver metastases and the effect on regeneration and outcome after liver resection

Management of colorectal liver metastases (CRLM) has dramatically changed during the last decade and has now become more multimodal and aggressive, including the use of downstaging chemotherapy, portal vein embolization to increase the function of the liver remnant or both in combination. Radiofrequency ablation is also an option in CRLM, potentially combined with surgical resection. Results are quite convincing concerning the safety of liver resection also when performed following neoadjuvant chemotherapy. Sparing liver parenchyma in patients with bilobar liver metastatic disease subjected to liver resection may be possible without endangering surgical radicality. Sparing liver parenchyma when using neoadjuvant chemotherapy, a chemotherapy-free period of 6 weeks or more seems to positively affect liver regeneration. There is still the possibility to reresect recurrent liver lesions, though there seems to be a tendency toward fewer reresections following the use of adjuvant chemotherapy.

Liver regeneration and the atrophy-hypertrophy complex

The atrophy-hypertrophy complex (AHC) refers to the controlled restoration of liver parenchyma following hepatocyte loss. Different types of injury (e.g., toxins, ischemia/reperfusion, biliary obstruction, and resection) elicit the same hypertrophic response in the remnant liver. The AHC involves complex anatomical, histological, cellular, and molecular processes. The signals responsible for these processes are both intrinsic and extrinsic to the liver and involve both physical and molecular events. In patients in whom resection of large liver malignancies would result in an inadequate functional liver remnant, preoperative portal vein embolization may increase the remnant liver sufficiently to permit aggressive resections. Through continued basic science research, the cellular mechanisms of the AHC may be maximized to permit curative resections in patients with potentially prohibitive liver function.

Sequential arterial and portal vein embolization in patients with cirrhosis and hepatocellular carcinoma: the hospital beaujon experience

When feasible, hepatic resection is the treatment of choice for large hepatocellular carcinoma (HCC). Because HCC is often developed on chronic liver disease, which is known to have limited regeneration capacity, major hepatic resections are often contraindicated. Portal vein embolization (PVE) has been introduced to extend the indications for major hepatic resection and to increase the safety of the surgical procedure. However, hypertrophy after PVE is often less than in normal liver. It has been suggested that preoperative sequential arterial embolization and PVE have a strong anticancer effect and could increase the rate of hypertrophy more than PVE alone. In our experience, sequential arterial embolization and PVE effectively increase the future liver remnant and induce a high rate of complete tumor necrosis. This combined procedure should broaden the indication for major resection in chronic liver disease.

Strategies for resection using portal vein embolization: hepatocellular carcinoma and hilar cholangiocarcinoma

Preoperative portal vein embolization (PVE) is increasingly used to optimize the volume and function of the future liver remnant (FLR) and to reduce the risk for complications of major hepatectomy for hepatocellular carcinoma (HCC) or hilar cholangiocarcinoma (CCA). In patients with HCC who are candidates for extended hepatectomy and in patients with HCC and well-compensated cirrhosis who are being considered for major hepatectomy, FLR volumetry is routinely performed, and PVE is employed in selected cases to optimize the volume and function of the FLR prior to surgery. Similarly, in patients with hilar CCA who are candidates for extended hepatectomy, careful preoperative preparation using biliary drainage, FLR volumetry, and PVE optimizes the volume and function of the FLR prior to surgery. Appropriate use of PVE has led to improved postoperative outcomes after major hepatectomy for these diseases and oncological outcomes similar to those in patients who undergo resection without PVE. Specific indications for PVE are being clarified. FLR volumetry is necessary for proper selection of patients for PVE. Analysis of the degree of hypertrophy of the FLR after PVE (a dynamic test of liver regeneration) complements analysis of the pre-PVE FLR volume (a static test). Together, FLR degree of hypertrophy and FLR volume are the best predictors of outcome after major hepatectomy in an individual patient, regardless of the degree of underlying liver disease. This article synthesizes the literature on the approach to patients with HCC and CCA who are candidates for major hepatectomy. The rationale and indications for FLR volumetry and PVE and outcomes following PVE and major hepatectomy for HCC and CCA are discussed.

Patient selection for surgical management of primary and metastatic liver cancers: current perspectives

The surgical management of liver malignancies remains a mainstay in the treatment of such patients, and has benefited from dramatic advancements over the last two decades. Improvements in surgical technique, better understanding of hepatic anatomy, and improvement in anesthesiological supportive care has resulted in a decline in perioperative morbidity and operative mortality. Proper patient selection for surgical and nonsurgical treatment currently employs a multidisciplinary approach in our institution. This review will focus on the surgical treatment options for both primary and secondary liver cancers.

Increase in future remnant liver function after preoperative portal vein embolization

BACKGROUND

Preoperative portal vein embolization (PVE) is performed in patients with insufficient future remnant liver (FRL) to allow safe resection. Although many studies have demonstrated an increase in FRL volume after PVE, little is known about the increase in FRL function. This study evaluated the increase in FRL function after PVE using (⁹⁹m) Tc-labelled mebrofenin hepatobiliary scintigraphy (HBS) with single photon emission computed tomography (SPECT) and compared this with the increase in FRL volume.

METHODS

In 24 patients, computed tomography volumetry and (⁹⁹m) Tc-labelled mebrofenin HBS with SPECT were performed before and 3-4 weeks after PVE to measure FRL volume, standardized FRL and FRL function. A hypothetical model was used to assess safe resectability after PVE. The limit for safe resection for FRL function was set at an uptake of 2·69 per cent per min per m². For FRL volume and standardized FRL, 25 or 40 per cent of total liver volume was used, depending on the presence of underlying liver disease.

RESULTS

After PVE, FRL function increased significantly more than FRL volume. The correlation between the increase in FRL volume and FRL function was poor. Using the hypothetical model, seven patients did not achieve a sufficient increase in FRL function to allow safe resection 3-4 weeks after PVE, compared with 12 and nine patients based on FRL volume and standardized FRL respectively.

CONCLUSION

The increase in FRL function after PVE is more pronounced than the increase in FRL volume, suggesting that the necessary waiting time until resection may be shorter than indicated by volumetric parameters.

Milestones in the evolution of hepatic surgery

This paper describes the rapid evolution of modern liver surgery, starting in the middle of the twentieth century. Claude Couinaud studied and described the segmental anatomy of the liver, Thomas Starzl performed the first liver transplantations, and Henri Bismuth introduced the concept of anatomical resections. Hepatic surgery has developed significantly since those early days. To date, innovative techniques are applied, using cutting-edge technologies: Intraoperative ultrasound, techniques of vascular exclusion of the liver, new devices for performing homeostasis and dissection, laparoscopy for resections, and new drugs that allow the resection of previously unresectable tumors. The next stage in liver surgery will probably be the implementation of a multidisciplinary holistic approach to the liver-diseased patient that will ensure the best and most efficient treatments in the future.

Impaired liver regeneration of steatotic rats after portal vein ligation: a particular emphasis on (99m)Tc-DISIDA scintigraphy and adiponectin signaling

BACKGROUND & AIMS

Portal vein ligation (PVL) is increasingly employed prior to major hepatectomy in order to enhance the volume of the future liver remnant (FLR) and to avoid post-hepatectomy liver failure. The efficacy of PVL on subjects with non-alcohol fatty liver disease (NAFLD) is largely unknown.

METHODS

Sprague-Dawley rats fed with normal diet (control) and methionine-choline deficient diet (MCD) were used. The animals underwent PVL and were sacrificed at indicated time points.

RESULTS

Livers from MCD rats exhibited a decreased BrdU and Ki-67 labelling index, and an increased apoptotic index after PVL compared to normal rats; as a net effect, MCD rats exhibited a decrease in their restituted liver mass and redistributed volume ratio, compared to normal rats. Normal rats displayed similar serum levels of ICG15-R before and after PVL; whereas MCD rats displayed reduced ICG15-R after PVL. Using (99m)Tc-DISIDA scintigraphy examination, livers from MCD rats exhibited decreased HEF and prolonged TE(1/2) of FLR after PVL, indicating deteriorating hepatocyte function despite the shift in volume. The basal level of plasma TNFalpha, IL-1alpha, IL-1beta, and IL-10 of MCD rats was significantly increased before PVL compared to normal rats; however their plasma level did not increase in response to PVL as in normal rats. Hepatic adiponectin mRNA surged in MCD rats after PVL, whereas its receptors, AdipoR1 and AdipoR2, were paradoxically down-regulated. PPARalpha, a down-stream molecule of AdipoR2 axis, was also decreased in MCD rats.

CONCLUSIONS

Reduced regenerated liver mass and deteriorated hepatocyte function of the FLR from steatotic rats after PVL may be associated with deranged Kupffer cell-mediated cytokine expression and disrupted adiponectin signalling.

Prediction of posthepatectomy hepatic functional reserve by serum hyaluronate

BACKGROUND

Serum hyaluronate can be used as an index of hepatic sinusoidal endothelial cell function and hepatic fibrosis. This study was designed to clarify the clinical significance of the serum hyaluronate level as a parameter of functional reserve.

METHODS

The study included 283 patients undergoing hepatectomy. Liver function parameters were examined before surgery and compared with outcomes. Patients were retrospectively grouped according to the presence or absence of postoperative hepatic dysfunction.

RESULTS

Preoperative serum hyaluronate levels were significantly raised in parallel with the degree of severity of the underlying chronic liver disease. Regression analysis revealed serum hyaluronate level to be an independent predictor of portal hypertension. In 131 patients undergoing major hepatectomy, preoperative hyaluronate levels were significantly higher in patients with poor outcome. Multivariable logistic regression analysis demonstrated serum hyaluronate and total bilirubin levels to be independent variables associated with postoperative hepatic dysfunction. Patients with high indocyanine green retention rate at 15 min (over 15 per cent) showed significantly higher morbidity and mortality rates when their serum hyaluronate levels were over 180 ng/ml.

CONCLUSION

Serum hyaluronate is a simple clinical marker for portal venous pressure and a reliable auxiliary parameter of hepatic functional reserve in combination with other liver function tests.

Improved hepatocyte function of future liver remnant of cirrhotic rats after portal vein ligation: a bonus other than volume shifting

BACKGROUND

Preoperative portal vein embolization is increasingly employed for those with hepatocellular carcinoma and cirrhosis to gain a volume-shifting effect. However, the alterations of histologic architecture and hepatocyte function of future liver remnant (FLR) remain unexplored.

METHODS

Portal vein ligation (PVL) was performed in cirrhotic and noncirrhotic rats. Regeneration indices that include the DNA synthesis index, restituted liver mass, and the redistributed volume ratio were measured. The indocyanine green 15' retention test (ICG-R15), histologic changes, total Knodell score, and activated hepatic stellate cells (HSCs) were measured before and after PVL. Tc-99m sulfur-colloid liver single photon emission computed tomography (SPECT) and diisopropyl iminoacetic acid (DISIDA) SPECT were conducted.

RESULTS

The redistributed volume ratio of cirrhotic rats was less than noncirrhotic rats (63% vs 80%, P < .01). The ICG-R15 of cirrhotic rats at day 7 after PVL was improved compared with baseline (6.0 +/- 4.1% vs 15.8 +/- 4.6%, P < .01). The total Knodell score and activated HSCs of FLR in cirrhotic rats both were decreased compared with those of baseline. The redistributed volume ratio of noncirrhotic and cirrhotic rats based on 99mTc sulfur-colloid SPECT were 79% and 64%, respectively. The clearance T(1/2) of FLR in cirrhotic rats based on DISIDA SPECT was decreased compared with baseline (5.2 +/- 1.9 min vs 8.6 +/- 3.1 min).

CONCLUSION

The regenerated functional liver mass of cirrhotic rats after PVL is less than noncirrhotic rats, whereas the hepatocyte function of FLR in cirrhotic rats is improved relevant to tissue remodeling.

Strategies for resection using portal vein embolization: metastatic liver cancer

The oncological landscape is constantly changing with the development of new curatively intended therapeutic strategies. More and more, liver metastases are amenable to resection following the progress achieved as a result of new oncological concepts (i.e., treat detectable disease with surgery and ablative therapies and treat the remaining nondetectable disease with efficient chemotherapy) as well as improved chemotherapeutic and ablation techniques. One of the major limitations to extending the indications for liver resection is the volume of the future remnant liver (FRL). To overcome these limitations, portal vein embolization (PVE) has played a key role in obtaining preoperative hypertrophy of the FRL and thus has reduced postoperative morbidity and mortality. Interestingly, thermal ablation of multiple bilateral liver metastases makes it difficult to predict the volume of parenchyma scheduled for ablation. Furthermore, prolonged chemotherapy impairs liver parenchyma function, which has a negative impact on liver hypertrophy. In the future, both volumetric and functional assessment of the FRL will be used to determine whether PVE is necessary before hepatectomy in individual patients and new strategies (e.g., PVE used alone or combined with other treatments; timing of PVE may vary) will be based on these principles. This article presents various current strategies for the use of PVE in patients with metastatic liver cancer.

Combined portal vein embolization and neoadjuvant chemotherapy as a treatment strategy for resectable hepatic colorectal metastases

OBJECTIVES

The objectives of this study are 1) to determine whether the future liver remnant will grow after portal vein embolization (PVE) in patients with colon cancer on concurrent chemotherapy and 2) to determine whether recovery after extended hepatectomy is improved after PVE.

PURPOSE

Neoadjuvant chemotherapy followed by hepatic resection is an increasingly used therapeutic strategy for curative treatment for colorectal metastases. However, such chemotherapy may result in steatosis, liver damage, and compromised liver regeneration and recovery. This study aims to determine whether PVE can be used during neoadjuvant therapy to enhance growth of future residual liver and to improve postoperative recovery.

METHODS

From September 1999 to September 2004, 100 patients with colorectal metastases to the liver were subjected to PVE as preparation for extended hepatic resection, 43 of whom were embolized during neoadjuvant chemotherapy. Liver growth was examined by computed tomography volumetric analysis. Clinical outcomes of the 71 patients subsequently resected were compared with 100 consecutive patients subjected to extended resection without PVE (controls).

RESULTS

After a median wait of 30 +/- 2 days after PVE, patients on neoadjuvant chemotherapy experienced a median contralateral (nonembolized) liver growth of 22% +/- 3% compared with 26% +/- 3% for those without chemotherapy (P = NS). The number of patients with <5% growth was also similar: 4 of 43 versus 6 of 57 (P = NS). Comparison of patients resected after PVE to a simultaneous cohort of 100 consecutive patients subjected to extended resection without prior PVE demonstrated a lower fresh frozen plasma requirement (P = 0.01), a lower peak bilirubin (P = 0.002), and a shorter length of stay (P = 0.03). Mortality was similar (0% vs. 2%).

CONCLUSIONS

Liver growth occurs after PVE even when cytotoxic chemotherapy is administered. No major complications occurred with PVE. Patients requiring major hepatic resection should be considered for PVE during neoadjuvant chemotherapy to improve subsequent recovery after resection.

Preoperative portal vein embolization for major liver resection: a meta-analysis

INTRODUCTION

Preoperative portal vein embolization (PVE) is used clinically to prevent postoperative liver insufficiency. The current study examined the impact of portal vein embolization on liver resection.

METHOD

A comprehensive Medline search to identify all registered literature in the English language on portal vein embolization. Meta-analysis was performed to assess the result of PVE and its impact on major liver resection.

RESULT

A total of 75 publications met the search criteria but only 37 provided data sufficiently enough for analysis involving 1088 patients. The overall morbidity rate for PVE was 2.2% without mortality. Four weeks following PVE, 85% patients underwent the planned hepatectomy (n = 930). Twenty-three patients had transient liver failure following resection after PVE (2.5%) but 7 patients developed acute liver failure and died (0.8%). The reason for nonresection following PVE (n = 158, 15%) included inadequate hypertrophy of remnant liver (n = 18), severe progression of liver metastasis (n = 43), extrahepatic spread (n = 35), refusal to surgery (n = 1), poor general condition (n = 1), altered treatment to transcatheter artery embolization or chemotherapy (n = 24), complete remission after treatment with 3 cycles of fluoracil and interferon alpha in a patient with hepatocellular carcinoma (n = 1), incomplete pre- or postembolization scanning (n = 8). Of those who underwent laparotomy without resection, (n = 27) reasons included intraoperative finding of peritoneal dissemination (n = 15), portal node metastasis (n = 2), severe invasion of the tumor to the hepatic artery and portal vein (n = 1), and gross tumoral extension precluding curative resection (n = 9). Two techniques were used for portal vein embolization: percutaneous transhepatic portal embolization, (PTPE) and transileocolic portal embolization, (TIPE). The increase in remnant liver volume was much greater in PTPE than TIPE group (11.9% vs. 9.7%; P = 0.00001). However, the proportion of patients who underwent resection following PVE was 97% in TIPE and 88% PTPE, respectively (P = <0.00001). Although there was no significant difference in patients who had major complications post-PVE, the rate for minor complications was significantly higher among patients who had PTPE (53.6% vs. 0%, P = <0.0001).

CONCLUSION

PVE is a safe and effective procedure in inducing liver hypertrophy to prevent postresection liver failure due to insufficient liver remnant.

Postoperative liver dysfunction and future remnant liver: where is the limit? Results of a prospective study

BACKGROUND

The future remnant liver (FRL) limit for safe major hepatectomy with low risk of postoperative liver failure has not yet been well defined.

METHODS

Between April 2000 and September 2004, every patient scheduled for major hepatectomy in our institution underwent CT-volumetry of FRL. Patients with FRL <25% underwent portal vein embolization (PVE). Exclusion criteria were PVE, associated vascular resection and liver cirrhosis. The FRL was correlated with short-term results in patients with normal liver (group A) and those with impaired liver function secondary to neoadjuvant chemotherapy or cholestasis (bilirubin >2 mg/100 ml) (group B). Liver dysfunction was defined as both PT <50% and serum bilirubin level >5 mg/100 ml for three or more consecutive days.

RESULTS

A total of 119 patients were analyzed, 72 in group A and 47 in group B. The FRL value was the only significant risk factor for postoperative liver dysfunction in the univariate and multivariate analysis (p = 0.009). The FRL did not correlate with postoperative mortality and morbidity. Bilirubin and prothrombin time (PT) on days 3 and 7 were significantly correlated to FRL in both groups. In group A, patients with postoperative liver dysfunction had a FRL<30% (3 versus 0; p = 0.005). According to receiving operator characteristic (ROC) curve analysis, a FRL value of 26.5% predicted postoperative liver dysfunction with 66.7% sensitivity, 97.1% specificity, 50% positive predictive value (PPV), and 98.5% negative predictive value (NPV). In group B, patients with postoperative liver dysfunction had a FRL <35% (4 versus 0; p = 0.027). According to ROC curve analysis, a FRL value of 31.05% predicted postoperative liver dysfunction with 75% sensitivity, 79.1% specificity, 25% PPV, and 97.1% NPV.

CONCLUSIONS

Hepatectomy can be considered safe when FRL is >26.5% in patients with healthy liver and >31% in patients with impaired liver function.

Institutional guidelines and ongoing studies in management of liver tumours: the experience of the European Institute of Oncology

BACKGROUND

An institutional task force on upper gastrointestinal tumours is active at the European Institute of Oncology (EIO). Members decided to collate the institutional guidelines on management of liver tumours (primary and metastatic) into a document. This article is aimed at presenting the current treatment guidelines as well as ongoing research protocols and trials in this field at the EIO.

METHODS

A steering committee convened to assign tasks to individual members. Contributions from experts in each treatment area were collated in a single document, in order to produce a draft for subsequent review from the aforementioned committee. Six drafts have been discussed and the final version approved.

RESULTS

Surgical, medical oncology, interventional radiology, nuclear medicine and radiation therapy approaches, their roles in management of liver tumours and ongoing research trials are presented and discussed in this article.

CONCLUSIONS

At the EIO a multi-disciplinary integrated approach to liver tumours is standard and several ongoing research projects are currently active in this field.

Portal vein embolization before major hepatectomy and its effects on regeneration, resectability and outcome

BACKGROUND

This study evaluated the safety of portal vein embolization (PVE), its impact on future liver remnant (FLR) volume and regeneration, and subsequent effects on outcome after liver resection.

METHODS

Records of 112 patients were reviewed. Standardized FLR (sFLR) and degree of hypertrophy (DH; difference between the sFLR before and after PVE), complications and outcomes were analysed to determine cut-offs that predict postoperative hepatic dysfunction.

RESULTS

Ten (8.9 per cent) of 112 patients had PVE-related complications. Postoperative complications occurred in 34 (44 per cent) of 78 patients who underwent hepatic resection and the 90-day mortality rate was 3 per cent. A sFLR of 20 per cent or less after PVE or DH of not more than 5 per cent (versus sFLR greater than 20 per cent and DH above 5 per cent) had a sensitivity of 80 per cent and a specificity of 94 per cent in predicting hepatic dysfunction. Overall, major and liver-related complications, hepatic dysfunction or insufficiency, hospital stay and 90-day mortality rate were significantly greater in patients with a sFLR of 20 per cent or less or DH of not more than 5 per cent compared with patients with higher values.

CONCLUSION

DH contributes prognostic information additional to that gained by volumetric evaluation in patients undergoing PVE.

Trans-ileocecal portal vein embolization as a preoperative treatment for right trisegmentectomy with caudate lobectomy

BACKGROUND AND OBJECTIVES

The indication of preoperative portal vein embolization (PVE) has been expanded to hepatocellular carcinoma, cholangiocellular carcinoma (CCC), hepatic metastasis, and gallbladder (GB) cancer as well as hilar cholangiocarcinoma (hCC). However, biliary cancers sometimes cause peritoneal dissemination.

PATIENTS AND METHODS

We performed our preoperative trans-ileocecal-vein PVE (TIPE) method on 14 (3 GB cancer, 1 CCC, and 10 hCC), whose estimated residual liver volume was <30%.

RESULTS

Out of 14 patients, peritoneal dissemination was encountered in two patients with GB cancer and one with hCC (21.4%) during our procedure. The estimated residual liver volume was 37.4 +/- 2.7% at 14 days after PVE in patients without predisposing cholangitis, while those in patients with cholangitis was 29.3 +/- 1.3% (P = 0.0002). No major complication due to the procedure was encountered in this series.

CONCLUSIONS

PTPE could be the first choice for patients with hCC, hepatocellular carcinoma, and hepatic metastases. Although the TIPE proposed here has some potential disadvantages, we would recommend it especially for patients with GB cancer because of its high potential to cause cancerous peritonitis. When a patient had predisposing cholangitis, radical operation should be scheduled on >21 days after PVE rather than on 14 days.

Practical questions in liver metastases of colorectal cancer: general principles of treatment

Liver metastases of colorectal cancer are currently treated by multidisciplinary teams using strategies that combine chemotherapy, surgery and ablative techniques. Many patients classically considered non-resectable can now be rescued by neoadjuvant chemotherapy followed by liver resection, with similar results to those obtained in initial resections. While many of those patients will recur, repeat resection is a feasible and safe approach if the recurrence is confined to the liver. Several factors that until recently were considered contraindications are now recognized only as adverse prognostic factors and no longer as contraindications for surgery. The current evaluation process to select patients for surgery is no longer focused on what is to be removed but rather on what will remain. The single most important objective is to achieve a complete (R0) resection within the limits of safety in terms of quantity and quality of the remaining liver. An increasing number of patients with synchronous liver metastases are treated by simultaneous resection of the primary and the liver metastatic tumours. Multilobar disease can also be approached by staged procedures that combine neoadjuvant chemotherapy, limited resections in one lobe, embolization or ligation of the contralateral portal vein and a major resection in a second procedure. Extrahepatic disease is no longer a contraindication for surgery provided that an R0 resection can be achieved. A reverse surgical staged approach (liver metastases first, primary second) is another strategy that has appeared recently. Provided that a careful selection is made, elderly patients can also benefit from surgical treatment of liver metastases.

Hepatocyte morphology and kinetics after portal vein embolization

BACKGROUND

Macroscopic volume changes after portal vein embolization (PVE) can be assessed accurately by computed tomography, but histological changes remain poorly understood. The aim of this study was to clarify hepatocyte morphology and kinetics after PVE.

METHODS

The resected livers from 25 patients who underwent extended hepatectomy after PVE and five normal livers were examined using hepatocyte paraffin 1 staining for histomorphometric analysis of hepatocytes. Cell kinetics were determined by Ki-67 staining and terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick-end labelling assay. Kupffer cells were examined by CD68 immunostaining.

RESULTS

The number of hepatocytes was similar in the embolized lobe, non-embolized lobe and normal liver, but hepatocyte volume was greater in the non-embolized lobe than in the embolized lobe (P = 0.017). The Ki-67 labelling index was higher in the non-embolized lobe (P < 0.001) whereas the apoptotic index was higher in the embolized lobe (P < 0.001). There were more Kupffer cells per unit area in the embolized lobe (P < 0.001).

CONCLUSION

Hepatocyte hypertrophy and replication leads to volume enlargement of the non-embolized hepatic lobe, whereas hepatocyte atrophy and apoptosis causes a decrease in volume of the embolized lobe.