Extension of surgical indications for hepatocellular carcinoma by portal vein embolization

Portal vein embolization with N-butyl-cyanoacrylate improves liver hypertrophy compared to microparticles - A Swedish multicenter cohort study

Background

An adequate future liver remnant (FLR) is fundamental for major liver resections. To achieve sufficient FLR, portal vein embolization (PVE) may be used. The most effective material for PVE has yet to be determined. The aim of this study was to investigate the differences in FLR growth between n-butyl-cyanoacrylate glue (NBCA) and microparticles.

Material/methodsa

retrospective study was performed at three Swedish hepatobiliary centers and included patients who underwent PVE 2013-2021. Electronic medical records were reviewed, and procedure-related data were collected. Data were analyzed with respect to embolizing material.

Results

A total of 265 patients were included: 160 in the NBCA group and 105 in the microparticle group. The NBCA group had a higher degree of hypertrophy (12.1 vs. 9.4 % points, p = 0.003) and a higher resection rate (68 vs. 59 %, p = 0.01) than the microparticle group. Procedure-related data all indicated the superiority of NBCA. No difference in inducing hypertrophy was observed when comparing patients who received chemotherapy before PVE with those who received chemotherapy before and after PVE within the NBCA group.

Discussion/conclusion

This retrospective multicenter study supports the superiority of NBCA compared to microparticles in the setting of PVE. Chemotherapy after PVE does not seem to negatively affect hypertrophy.

Percutaneous radiological interventions of the portal vein: a comprehensive review

The portal vein is the largest vessel supplying the liver. A number of radiological interventions are performed through the portal vein, namely for primary pathologies of the portal vein, for inducing liver hypertrophy or to treat the sequelae of portal hypertension among others. The routes used include direct transhepatic, transjugular, and, uncommonly, trans-splenic and through subcutaneous varices. Portal vein embolization and transjugular intrahepatic portosystemic shunt are among the most common portal vein interventions that are performed to induce hypertrophy of the future liver remnant and to treat complications of portal hypertension, respectively. Other interventions include transhepatic obliteration of varices and shunts, portal vein thrombolysis, portal vein recanalization, pancreatic islet cell transplantation, and embolization of portal vein injuries. We present a detailed illustrative review of the various radiological portal vein interventions.

Locoregional Approaches in Cholangiocarcinoma Treatment

Cholangiocarcinoma (CCA) is a rare hepatic malignant tumor with poor prognosis due to late detection and anatomic factors limiting the applicability of surgical resection. Without surgical resection, palliation is the most common approach. In non-surgical cases contained within the liver, locoregional therapies provide the best chance for increased survival and disease control. The most common methods, transarterial chemoembolization and transarterial radioembolization, target tumors by embolizing their blood supply and limiting the tumor's ability to metabolize. Other treatments induce direct damage via thermal ablation to tumor tissue to mediate their anti-tumor efficacy. Recent studies have begun to explore roles for these therapies outside their previous role of palliation. This review will outline the mechanisms of each of these treatments, along with their effects on overall survival, while comparing these to non-locoregional therapies.

Safety and outcomes of pre-operative portal vein embolization using N-butyl cyanoacrylate (Glue) in hepatobiliary malignancies: A single center retrospective analysis

Aims and Objectives:

To evaluate the outcome of preoperative portal vein embolization (PVE) using N-butyl cyanoacrylate (NBCA) for change in future liver remnant (FLR) volume, biochemical changes, and procedure-related complications. The factors affecting FLR hypertrophy and the rate of resection was also evaluated for this cohort.

Materials and Methods:

From 2012 to 2017, PVE utilizing NBCA mixed with lipiodol (1:4) was performed using percutaneous approach in 28 patients with hepatobiliary malignancies with low FLR. All patients underwent volumetric computed tomography (CT) assessment before and at 3–5 weeks after PVE and total liver volume (TLV), FLR volume, and FLR/TLV ratio, changes in portal vein diameter and factors affecting FLR were evaluated. Complications and the resectability rate were recorded and analyzed.

Result:

PVE was successful in all 28 patients. The mean FLR increased by 52% ± 32% after PVE (P < 0.0001). The FLR/TLV ratio was increased by 14.2% ± 2.8% (P < 0.001). Two major complications were encountered without any impact on surgery. There was no significant change seen in liver function test and complete blood counts after PVE. Eighteen patients (64.28%) underwent hepatic resection without any liver failure, and only three patients developed major complication after surgery. Remaining ten patients did not undergo surgery because of extrahepatic metastasis detected either on follow-up imaging or staging laparotomy. Patients with diabetes showed a lower rate of hypertrophy (P < 0.05).

Conclusion:

Preoperative PVE with NBCA is safe and effective for increasing FLR volume in patients of all age group and even in patients with an underlying liver parenchymal disease with hepatobiliary malignancy. Lesser hypertrophy was noted in patients with diabetes. A reasonable resectability was achieved despite having a high rejection in gall bladder cancer subgroup due to rapid disease progression.

An observational study to determine volume changes in the functional liver remnant following portal vein embolization

Background and Aim

Portal vein embolization (PVE) prior to hepatic resection reduces the risk of hepatic insufficiency in the postoperative period by redistributing blood from the embolized unhealthy liver to the healthy liver, termed the functional liver remnant (FLR). A retrospective analysis of liver volumes after embolization in a single institution was performed to identify change in volume of the FLR and determine factors affecting this change.

Methods

Between 2013 and 2015, 21 patients undergoing PVE followed by hepatic resection for varied indications (colorectal metastases, hepatocellular carcinoma, cholangiocarcinoma, etc.) were included in this study. n-butyl cyanoacrylate glue diluted with Lipiodol (35-45% strength) along with 75-100 μm of polyvinyl alcohol particles were used for embolization. Liver volumetric determination was performed before and after PVE and volume changes in the FLR were analyzed. Biochemical factors and factors affecting FLR hypertrophy were also analyzed.

Results

Majority of the patients (n = 18) underwent right-lobe embolization. All were performed using the ipsilateral approach. No major complications occurred with only one patient developing post-procedural ascites requiring percutaneous draining. A significant increase in the mean volume of the FLR by 63.7% ± 91.6%, P = 0.001 was noted after PVE. The FLR/total liver volume (TLV) increased significantly by 17% ± 18%. No significant demographic factors affected FLR hypertrophy and no significant biochemical changes were noted. Thirteen patients were successfully operated on after embolization.

Conclusions

PVE is effective in inducing significant hypertrophy of the future FLR, prior to hepatic resection in our institution.

Portal Vein Embolization with PVA and Coils before Major Hepatectomy: Single-Center Retrospective Analysis in Sixty-Four Patients

Objectives

Portal vein embolization (PVE) stimulates hypertrophy of the future liver remnant (FLR) and improves the safety of extended hepatectomy. This study evaluated the efficacy of PVE, performed with PVA and coils, in relation to its effect on FLR volume and ratio. Secondary endpoints were the assessment of PVE complications, accomplishment of liver surgery, and patient outcome after hepatectomy.

Materials and Methods

All patients who underwent PVE before planned major hepatectomy between 2013 and 2017 were retrospectively analyzed, comprising a total of 64 patients. Baseline patient clinical characteristics, imaging records, liver volumetric changes, complications, and outcomes were analyzed.

Results

There were 45 men and 19 women with a mean age of 64 years. Colorectal liver metastasis was the most frequent liver tumor. The majority of patients (n = 53) had a right PVE. FLR increased from a mean value of 484 ml ± 242 to 654 ml ± 287 (p < 0.001) after PVE. Two major complications were experienced after PVE: 1 case of left hepatic artery branch laceration and 1 case of hemoperitoneum and hemothorax. A total of 44 (69%) patients underwent liver surgery. Twenty-one patients were not taken to surgery due to disease progression (n = 18), liver insufficiency (n = 1), and insufficient FLR volume (n = 1), and one patient declined surgery (n = 1).

Conclusions

PVE with PVA and coils was accomplished safely and promoted a high FLR hypertrophy yield, enabling most of our patients to be submitted to the potentially curative treatment of liver tumor resection.

CD133 + cell infusion in patients with colorectal liver metastases going to be submitted to a major liver resection (CELLCOL): A randomized open label clinical trial

BACKGROUND

Treatment of liver metastases of colorectal carcinoma is surgical resection. However, only 10-15% of the patients in this context will be candidate for curative resection arising other 10-13% after response to neoadyuvant chemotherapy. In order to perform the liver metastases surgery, it is necessary to have a sufficient remnant liver volume (RLV) which allows maintaining an optimal liver function after resection. Studies on liver regeneration have determined that CD133 + stem cells are involved in liver hypertrophy developed after an hepatectomy with encouraging results. As presented in previous studies, CD133 + stem cells can be selected from peripheral blood after stimulation with G-CSF, being able to obtain a large number of them. We propose to treat patients who do not meet criteria for liver metastases surgery because of insufficient RLV (<40%) with CD133 + cells together with portal embolization, in order to achieve enough liver volume which avoids liver failure.

METHODS

/Design: The aim of this study is to evaluate the effectiveness of preoperative PVE plus the administration of CD133 + mobilized from peripheral blood with G-CSF compared to PVE only. SECONDARY AIMS ARE: to compare the grade of hypertrophy, speed and changes in liver function, anatomopathological study of hypertrophied liver, to determine the safety of the treatment and analysis of postoperative morbidity and surveillance.

STUDY DESIGN

Prospective randomized longitudinal phase IIb clinical trial, open, to evaluate the efficacy of portal embolization (PVE) together with the administration of CD133 + cells obtained from peripheral blood versus PVE alone, in patients with hepatic metastasis of colorectal carcinoma (CCRHM).

DISCUSSION

The number of CD133 + obtained from peripheral blood after G -CSF stimulation will be far greater than the number obtained with direct puncture of bone marrow. This will allow a greater intrahepatic infusion, which could have a direct impact on achieving a larger and quicker hypertrophy. Consequently, it will permit the treatment of a larger number of patients with an increase on their survival.

TRIAL REGISTRATION

ClinicalTrials.gov, ID NCT03803241.

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.

Preoperative strategies to improve resectability for hepatocellular carcinoma: a systematic review and meta-analysis

BACKGROUND

Preoperative strategies to increase the future liver remnant are useful methods to improve resectability rates for patients with hepatocellular carcinoma (HCC). The aim of this study was to perform a systematic review and meta-analysis of the main strategies used for this purpose.

METHODS

A systematic review was performed in PubMed, EMBASE, Cochrane and Scielo/LILACS. The procedures included for analysis were portal vein embolization or ligation (PVE/PVL), sequential transarterial embolization and PVE (TACE + PVE), radioembolization (RE) and associated liver partition and portal vein ligation for staged hepatectomy (ALPPS). Perioperative morbidity and mortality, post-hepatectomy liver failure (PHLF), and survival rates were evaluated.

RESULTS

A total of 46 studies were included in the systematic review (1284 patients). Resection rate was higher in TACE + PVE (90%; N = 315) when compared to PVE/PVL (75%; N = 254; P = <0.001) and similar to ALPPS (84%; N = 43; P = 0.374) and RE (100%; N = 28; P = 0.14). ALPPS was associated with higher PHLF and perioperative mortality rates when compared to PVE/PVL and TACE + PVE. ALPPS and RE showed higher risk of major complications than PVE/PVL and TACE + PVE.

CONCLUSION

Preoperative strategies to increase liver volume are effective in achieving resectability of HCC. TACE + PVE is as safe as PVL/PVE providing higher OS. ALPPS is associated with a higher risk of PHLF, major complications, and mortality. RE despite the small experience seems to present similar resection rate and OS as TACE + PVE with higher rate of major complications.

Conversion therapy and suitable timing for subsequent salvage surgery for initially unresectable hepatocellular carcinoma: What is new?

AIM

To review the conversion therapy for initially unresectable hepatocellular carcinoma (HCC) patients and the suitable timing for subsequent salvage surgery.

METHODS

A PubMed search was undertaken from 1987 to 2017 to identify articles using the keywords including “unresectable” “hepatocellular carcinoma”, ”hepatectomy”, ”conversion therapy”, “resection”, “salvage surgery” and “downstaging”. Additional studies were investigated through a manual search of the references from the articles. The exclusion criteria were duplicates, case reports, case series, videos, contents unrelated to the topic, comments, and editorial essays. The main and widely used conversion therapies and the suitable timing for subsequent salvage surgery were discussed in detail. Two members of our group independently performed the literature search and data extraction.

RESULTS

Liver volume measurements [future liver remnant (FLR)/total liver volume or residual liver volume/bodyweight ratio] and function tests (scoring systems and liver stiffness) were often performed in order to justify whether patients were suitable candidates for surgery. Successful conversion therapy was usually defined as downstaging the tumor, increasing FLR and providing subsequent salvage surgery, without increasing complications, morbidity or mortality. The requirements for performing salvage surgery after transcatheter arterial chemoembolization were the achievement of a partial remission in radiology, the disappearance of the portal vein thrombosis, and the lack of extrahepatic metastasis. Patients with a standardized FLR (sFLR) > 20% were good candidates for surgery after portal vein embolization, while other predictive parameters like growth rate, kinetic growth rate were treated as an effective supplementary. There was probably not enough evidence to provide a standard operation time after associating liver partition and portal vein ligation for staged hepatectomy or yttrium-90 microsphere radioembolization. The indications of any combinations of conversion therapies and the subsequent salvage surgery time still need to be carefully and comprehensively evaluated.

CONCLUSION

Conversion therapy is recommended for the treatment of initially unresectable HCC, and the suitable subsequent salvage surgery time should be reappraised and is closely related to its previous therapeutic effect.

Portal Vein Embolization: History and Current Indications

Portal vein embolization (PVE) was first adapted for patients undergoing major hepatectomy for hepatocellular carcinoma (HCC). In these patients, PVE caused hypertrophy of the unaffected liver and increased the volumetric ratio of future liver remnant (FLR) to total liver volume. ^99mTechnetium-galactosyl human serum albumin (^99mTc-GSA) scintigraphy revealed that PVE also induced a shift in hepatic function from the embolized part to the nonembolized part of the liver. Various hepatobiliary malignancies can be treated using PVE, and PVE is increasingly being used to expand the indication for major hepatectomy in patients with initially insufficient FLR volume or function. The indication for PVE is determined by the underlying liver function and standardized FLR volume. In patients with chronic hepatitis, the histologic inflammatory activity was negatively correlated with the increase in FLR volume, and PVE is not suitable for patients with high serum 7s collagen concentrations (>8 ng/ml). This finding may predict the efficacy of PVE. PVE before major hepatectomy can act as a tolerance test to avoid postoperative hepatic failure. PVE also improved long-term survival after liver resection in patients with HCC. Presently, PVE is a safe and useful treatment for patients undergoing major hepatectomy.

A novel utility of 99mTc-GSA SPECT/CT fusion imaging: detection of inadequate portal vein embolization

PURPOSE

Our aim was to determine the utility of Tc-99m-diethylenetriaminepentaacetic acid-galactosyl human serum albumin single-photon-emission computed tomography (^99mTc-GSA SPECT/CT) fusion imaging for detecting incomplete portal vein embolization (PVE).

MATERIALS AND METHODS

Fifty-five candidates underwent PVE. Among them, five underwent second PVE. Detectability of first inadequate PVE using CT and ^99mTc-GSA SPECT/CT fusion imaging was analyzed.

RESULTS

Cases of inadequate PVE were detected in three patients using CT and in five using ^99mTc-GSA SPECT/CT fusion imaging. Fusion imaging detected two cases of insufficient PVE in which portal branches were apparently well embolized on CT. Median value for volumetric rate in the embolized liver was 63.3% after the first PVE and 54.7% after the second (P < 0.01). Median functional rate value in embolized liver was 60.1% after the first PVE and 49.4% after the second (P < 0.01). Median value for change of volumetric and functional rates in embolized liver after the second PVE was 7.1 and 10.3%, respectively, and change of functional rate was greater than that of volumetric rate (P < 0.01).

CONCLUSIONS

^99mTc-GSA SPECT/CT fusion imaging was useful for detecting inadequate PVE, and second PVE was effective for increasing volumetric and functional rates.

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.

Preoperative portal vein embolization for hepatocellular carcinoma: Consensus and controversy

Thirty years have passed since the first report of portal vein embolization (PVE), and this procedure is widely adopted as a preoperative treatment procedure for patients with a small future liver remnant (FLR). PVE has been shown to be useful in patients with hepatocellular carcinoma (HCC) and chronic liver disease. However, special caution is needed when PVE is applied prior to subsequent major hepatic resection in cases with cirrhotic livers, and volumetric analysis of the liver segments in addition to evaluation of the liver functional reserve before PVE is mandatory in such cases. Advances in the embolic material and selection of the treatment approach, and combined use of PVE and transcatheter arterial embolization/chemoembolization have yielded improved outcomes after PVE and major hepatic resections. A novel procedure termed the associating liver partition and portal vein ligation for staged hepatectomy has been gaining attention because of the rapid hypertrophy of the FLR observed in patients undergoing this procedure, however, application of this technique in HCC patients requires special caution, as it has been shown to be associated with a high morbidity and mortality even in cases with essentially healthy livers.

Preoperative portal vein embolization in liver cancer: indications, techniques and outcomes

Postoperative liver failure is a severe complication of major hepatectomies, in particular in patients with a chronic underlying liver disease. Portal vein embolization (PVE) is an approach that is gaining increasing acceptance in the preoperative treatment of selected patients prior to major hepatic resection. Induction of selective hypertrophy of the non-diseased portion of the liver with PVE in patients with either primary or secondary hepatobiliary, malignancy with small estimated future liver remnants (FLR) may result in fewer complications and shorter hospital stays following resection. Additionally, PVE performed in patients initially considered unsuitable for resection due to lack of sufficient remaining normal parenchyma may add to the pool of candidates for surgical treatment. A thorough knowledge of hepatic segmentation and portal venous anatomy is essential before performing PVE. In addition, the indications and contraindications for PVE, the methods for assessing hepatic lobar hypertrophy, the means of determining optimal timing of resection, and the possible complications of PVE need to be fully understood before undertaking the procedure. Technique may vary among operators, but cyanoacrylate glue seems to be the best embolic agent with the highest expected rate of liver regeneration for PVE. The procedure is usually indicated when the remnant liver accounts for less than 25-40% of the total liver volume. Compensatory hypertrophy of the non-embolized segments is maximal during the first 2 weeks and persists, although to a lesser extent during approximately 6 weeks. Liver resection is performed 2 to 6 weeks after embolization. The goal of this article is to discuss the rationale, indications, techniques and outcomes of PVE before major hepatectomy.

Volume change and liver parenchymal signal intensity in Gd-EOB-DTPA-enhanced magnetic resonance imaging after portal vein embolization prior to hepatectomy

Purpose. To investigate the liver volume change and the potential of early evaluation by contrast-enhanced magnetic resonance imaging (MRI) using gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) after portal vein embolization (PVE). Materials and Methods. Retrospective evaluations of computed tomography (CT) volumetry of total liver and nonembolized areas were performed before and 3 weeks after PVE in 37 cases. The percentage of future liver remnant (%FLR) and the change ratio of %FLR (%FLR ratio) were calculated. Prospective evaluation of signal intensities (SIs) was performed to estimate the role of Gd-EOB-DTPA-enhanced MRI as a predictor of hypertrophy in 16 cases. The SI contrast between embolized and nonembolized areas was calculated 1 week after PVE. The change in SI contrast before and after PVE (SI ratio) was also calculated in 11 cases. Results. %FLR ratio significantly increased, and SI ratio significantly decreased (both P < 0.01). There were significant negative correlations between %FLR and SI contrast and between %FLR and SI ratio (both P < 0.01). Conclusion. Hypertrophy in the nonembolized area after PVE was indicated by CT volumetry, and measurement of SI contrast and SI ratio in Gd-EOB-DTPA-enhanced MRI early after PVE may be useful to predict the potential for hepatic hypertrophy.

Remnant growth rate after portal vein embolization is a good early predictor of post-hepatectomy liver failure

BACKGROUND

After portal vein embolization (PVE), the future liver remnant (FLR) hypertrophies for several weeks. An early marker that predicts a low risk of post-hepatectomy liver failure can reduce the delay to surgery.

STUDY DESIGN

Liver volumes of 153 patients who underwent a major hepatectomy (>3 segments) after PVE for primary or secondary liver malignancy between September 1999 and November 2012 were retrospectively evaluated with computerized volumetry. Pre- and post-PVE FLR volume and functional liver volume were measured. Degree of hypertrophy (DH = post-FLR/post-functional liver volume - pre-FLR/pre-functional liver volume) and growth rate (GR = DH/weeks since PVE) were calculated. Postoperative complications and liver failure were correlated with DH, measured GR, and estimated GR derived from a formula based on body surface area.

RESULTS

Eligible patients underwent 93 right hepatectomies, 51 extended right hepatectomies, 4 left hepatectomies, and 5 extended left hepatectomies. Major complications occurred in 44 patients (28.7%) and liver failure in 6 patients (3.9%). Nonparametric regression showed that post-embolization FLR percent correlated poorly with liver failure. Receiver operating characteristic curves showed that DH and GR were good predictors of liver failure (area under the curve [AUC] = 0.80; p = 0.011 and AUC = 0.79; p = 0.015) and modest predictors of major complications (AUC = 0.66; p = 0.002 and AUC = 0.61; p = 0.032). No patient with GR >2.66% per week had liver failure develop. The predictive value of measured GR was superior to estimated GR for liver failure (AUC = 0.79 vs 0.58; p = 0.046).

CONCLUSIONS

Both DH and GR after PVE are strong predictors of post-hepatectomy liver failure. Growth rate might be a better guide for the optimum timing of liver resection than static volumetric measurements. Measured volumetrics correlated with outcomes better than estimated volumetrics.

A review of animal models for portal vein embolization

BACKGROUND

Portal vein embolization (PVE) is a preoperative intervention to increase the future remnant liver (FRL) through regeneration of the non-embolized liver lobes. This review assesses all the relevant animal models of PVE available, to guide researchers who intend to study PVE.

MATERIALS AND METHODS

We performed a systematic literature search in Medline and Pubmed, from 1993-June 2013, using search headings "PVE" and "portal vein ligation". Articles were included when meeting the selection criteria: experimental animal study on PVE or portal vein ligation and experiments described in 5 animals or more.

RESULTS

Sixty-one articles were selected, describing six different animal models. Most articles reported experiments with rats, rabbits, and pigs. In rats, the increase in wet-weight ratio of the non-occluded liver or total liver weight is greatest in the first 7 d with values ranging from 75%-80.5% on day 7. The volume increase of FRL in the rabbit model is greatest in the first 7 d with values ranging from 33.6%-80% on day 7. In pigs, the largest gain in volume of the FRL was seen in the first 2 wk.

CONCLUSIONS

The choice of the model depends on the specific aim of the study. Evaluating the increase in liver volume and liver function after PVE, larger animals as the pig, rabbit, or the dog is useful because of the possibility to apply computed tomography volumetry. To evaluate mechanisms of regeneration after PVE, the rat model is useful, because of the variety of antibodies commercially available.

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.

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.

Volumetric changes after (90)y radioembolization for hepatocellular carcinoma in cirrhosis: an option to portal vein embolization in a preoperative setting?

BACKGROUND

Contralateral hypertrophy after (90)Y radioembolization has been described in case reports, but the incidence and quantitative extent of liver volume modifications after this therapy are unknown.

METHODS

This retrospective study examined patients with hepatocellular carcinoma and underlying cirrhosis treated by (90)Y radioembolization. The main inclusion criteria were unilateral treatment, no prior liver surgery, and computed tomographic scans allowing for volumetric assessments. Treated, tumor, and contralateral liver volumes were measured. Whole liver volume and the ratio of contralateral to total functional liver volume after a virtual hepatectomy were calculated.

RESULTS

Data of 34 patients were analyzed. Response rates were 26 % according to Response Evaluation Criteria in Solid Tumors (RECIST) and 63 % according to modified RECIST. Median overall survival was 13.5 months. Median treated volume decreased from 938 mL (interquartile range [IQR] = 719) to 702 mL (IQR = 656) (p < 0.001), while median contralateral volume increased from 724 mL (IQR = 541) to 920 mL (IQR = 530) (p < 0.001). The whole liver volume remained stable, with a median volume of 1,702 mL (IQR = 568) versus 1,577 mL (IQR 670), respectively (p = 0.55). The mean maximal increase in contralateral volume was 42 % (95 % confidence interval 16-67). Overall, 13 patients (38.2 %) exhibited increases greater than 30 %, while 13 patients (38.2 %) showed no increase or showed increases less than 10 %. The median ratio of contralateral to total functional liver volume increased from 48.5 to 64.9 % (p < 0.001), with the proportion of patients with a ratio of ≥50 % increasing from 47.1 to 67.6 % (p = 0.013).

CONCLUSIONS

(90)Y radioembolization induced frequent and similar increases in functional liver remnant volume compared with portal vein embolization. This technique should be tested in a prospective study phase 2 study before liver resection.

Ischemia/reperfusion in clamped lobes facilitates liver regeneration of non-clamped lobes after selective portal vein ligation

BACKGROUND

Hypertrophy of non-clamped liver lobes and the atrophy of clamped lobes have been shown to be interactive. Here, a rat model of selective lobe occlusion was established to study the effect of contralateral ischemia/reperfusion (I/R) on regeneration of non-clamped lobes.

METHODS

Left lateral and middle liver lobes were pretreated with I/R. In the experimental (IR + PVL) group, portal veins of the left and middle lobes were ligated. A group given similar portal vein ligation but no I/R (PVL) was the positive control.

RESULTS

Compared with the PVL group, the IR + PVL had higher, but not remarkable, levels of serum transaminases; weights of non-clamped lobes in the IR + PVL group comparatively increased much more notably. At 24-h post-surgery, the IR + PVL group's PCNA mRNA was up-regulated compared with the PVL group. At 72-h post-surgery, PCNA protein was up-regulated significantly, while TGF-β1 was down-regulated in the IR + PVL group notably, compared with the PVL group.

CONCLUSION

The I/R pretreatment given to the clamped lobes facilitates liver regeneration of non-clamped lobes after selective portal vein ligation, which may result from down-regulated TGF-β1 expression in non-clamped lobes.

Portal vein embolization before liver resection: a systematic review

Purpose

This is a review of literature on the indications, technique, and outcome of portal vein embolization (PVE).

Methods

A systematic literature search on outcome of PVE from 1990 to 2011 was performed in Medline, Cochrane, and Embase databases.

Results

Forty-four articles were selected, including 1,791 patients with a mean age of 61 ± 4.1 years. Overall technical success rate was 99.3 %. The mean hypertrophy rate of the FRL after PVE was 37.9 ± 0.1 %. In 70 patients (3.9 %), surgery was not performed because of failure of PVE (clinical success rate 96.1 %). In 51 patients (2.8 %), the hypertrophy response was insufficient to perform liver resection. In the other 17 cases, 12 did not technically succeed (0.7 %) and 7 caused a complication leading to unresectability (0.4 %). In 6.1 %, resection was cancelled because of local tumor progression after PVE. Major complications were seen in 2.5 %, and the mortality rate was 0.1 %. A head-to-head comparison shows a negative effect of liver cirrhosis on hypertrophy response. The use of n-butyl cyanoacrylate seems to have a greater effect on hypertrophy, but the difference with other embolization materials did not reach statistical significance. No difference in regeneration is seen in patients with cholestasis or chemotherapy.

Conclusions

Preoperative PVE has a high technical and clinical success rate. Liver cirrhosis has a negative effect on regeneration, but cholestasis and chemotherapy do not seem to have an influence on the hypertrophy response. The use of n-butyl cyanoacrylate may result in a greater hypertrophy response compared with other embolization materials used.

Role of portal vein embolization in hepatocellular carcinoma management and its effect on recurrence: a case-control study

BACKGROUND

Liver regeneration that occurs after portal vein embolization (PVE) may have adverse effects on the microscopic tumor foci in the residual liver mass in patients with hepatocellular carcinoma (HCC).

METHODS

Fifty-four HCC patients with inadequate functional residual liver volume were offered PVE during a seven-year period. Among them, 34 (63%) patients underwent curative resection. They were compared with a matched control group (n = 102) who underwent surgery without PVE. Postoperative complications, pattern of recurrence, and survival were compared between groups.

RESULTS

In the PVE group, a pre-embolization functional residual liver volume of 23% (12-33.5%) improved to 34% (20-54%) (p = 0.005) at the time of surgery. When the two groups were compared, minor (PVE, 24%; control, 29%; p = 0.651) and major (PVE, 18%; control, 15%; p = 0.784) complications were similar. After a follow-up period of 35 months (standard deviation 25 months), extrahepatic recurrences were detected in 10 PVE patients (29%) and 41 control patients (40%) (p = 0.310). Intrahepatic recurrences were seen in 10 (29%) and 47 (46%) cases (p = 0.109) in the PVE and control groups, respectively. In the PVE group, 41% (n = 14) of the recurrences were detected before one year, compared with 42% (n = 43) in the control group (p = 1). Disease-free survival rates at 1, 3, and 5 years were 57, 29, and 26% in the control group and 60, 42, and 42% in the PVE group (log-rank, p = 0.335). On multivariate analysis, PVE was not a factor affecting survival (p = 0.821).

CONCLUSIONS

Portal vein embolization increases the resectability of initially unresectable HCC due to inadequate functional residual liver volume, and it has no deleterious oncological effect after major resection of HCC.

31P MR spectroscopic imaging detects regenerative changes in human liver stimulated by portal vein embolization

PURPOSE

First, to evaluate hepatocyte phospholipid metabolism and energetics during liver regeneration stimulated by portal vein embolization (PVE) using proton-decoupled (31)P MR spectroscopic imaging ((31)P-MRSI). Second, to compare the biophysiologic differences between hepatic regeneration stimulated by PVE and by partial hepatectomy (PH).

MATERIALS AND METHODS

Subjects included six patients with hepatic metastases from colorectal cancer who were scheduled to undergo right PVE before definitive resection of right-sided tumor. (31)P-MRSI was performed on the left liver lobe before PVE and 48 h following PVE. Normalized quantities of phosphorus-containing hepatic metabolites were analyzed from both visits. In addition, MRSI data at 48 h following partial hepatectomy were compared with the data from the PVE patients.

RESULTS

At 48 h after PVE, the ratio of phosphomonoesters to phosphodiesters in the nonembolized lobe was significantly elevated. No significant changes were found in nucleoside triphosphates (NTP) and Pi values. The phosphomonoester (PME) to phosphodiester (PDE) ratio in regenerating liver 48 h after partial hepatectomy was significantly greater than PME/PDE 48 h after PVE.

CONCLUSION

(31)P-MRSI is a valid technique to noninvasively evaluate cell membrane metabolism following PVE. The different degree of biochemical change between partial hepatectomy and PVE indicates that hepatic growth following these two procedures does not follow the same course.

Sequential transcatheter arterial chemoembolization and portal vein embolization for hepatocellular carcinoma: the university of Tokyo experience

When undertaking portal vein embolization (PVE) in patients with hepatocellular carcinoma (HCC), the following possibilities should be considered: (1) failure to induce hypertrophy of the nonembolized segments due to the underlying liver disease, (2) acceleration of tumor growth by occlusion of the portal venous flow because HCC is a hypervascular tumor fed exclusively by hepatic arterial flow, and (3) poor efficacy of PVE due to the presence of arterioportal shunts frequently observed in cases of liver cirrhosis and HCC. With these in mind, we performed sequential transcatheter arterial chemoembolization (TACE) and PVE in 45 patients with HCC undergoing major liver resection. This double preparation was well tolerated, enhanced the hypertrophy process in the nonembolized segments, and suppressed the tumor growth during the preparation period. Furthermore, PVE also functioned as a preoperative test to select patients for major liver resection. Sequential TACE and PVE is an effective preoperative intervention in patients with HCC scheduled for major liver resection.

Percutaneous transhepatic portal vein embolization: rationale, technique, and outcomes

Portal vein embolization (PVE) is used to induce preoperative liver hypertrophy in patients with anticipated marginal future liver remnant (FLR) volumes who are otherwise potential candidates for resection. PVE can be performed utilizing the transhepatic contralateral and ipsilateral approaches. The transhepatic contralateral approach is the most commonly used technique worldwide, largely owing to its technical ease. However, the contralateral approach risks injuring the FLR, thereby compromising the planned surgical resection. The transhepatic ipsilateral approach offers a potentially safer alternative because the complications associated with this approach affect only the hepatic lobe that will be resected and are usually not serious enough to preclude surgery. This article discusses PVE using the transhepatic ipsilateral and contralateral approaches, including patient selection criteria, anatomical and technical considerations, and patient complications and outcomes.

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.

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.

Sequential transcatheter arterial chemoembolization and portal vein embolization versus portal vein embolization only before major hepatectomy for patients with hepatocellular carcinoma

PURPOSE

To evaluate the safety and efficacy of sequential transcatheter arterial chemoembolization (TACE) and portal vein embolization (PVE) prior to surgery in hepatocellular carcinoma (HCC) patients and to compare the clinical outcome of the combined procedure with that of a matched group of patients undergoing PVE alone.

PATIENTS AND METHODS

From 1997 to 2008, 135 patients with HCC underwent sequential TACE and PVE (n = 71) or PVE alone (n = 64) before right hepatectomy. PVE was performed mean 1.2 months after TACE. In both groups, computed tomography (CT) and liver volumetry were performed before and 2 weeks after PVE to assess degree of left lobe hypertrophy.

RESULTS

Baseline patient and tumor characteristics were similar in the two groups. After PVE, the chronological changes of liver enzymes were similar in the two groups. The mean increase in percentage future liver remnant (FLR) volume was higher in the TACE + PVE group (7.3%) than in the PVE-only group (5.8%) (P = 0.035). After surgery, incidence of hepatic failure was higher in the PVE-only group (12%) than in the TACE + PVE (4%) group (P = 0.185). Overall (P = 0.028) and recurrence-free (P = 0.001) survival rates were significantly higher in the TACE + PVE group than in the PVE-only group.

CONCLUSION

Sequential TACE and PVE before surgery is a safe and effective method to increase the rate of hypertrophy of the FLR and leads to longer overall and recurrence-free survival in patients with HCC.

Portal vein embolization: rationale, outcomes, controversies and future directions

Portal vein embolization (PVE) is now considered the standard of care to improve safety for patients undergoing extensive hepatectomy with an anticipated small future liver remnant (FLR). PVE is used to induce contralateral liver hypertrophy in preparation for major liver resection. Optimal patient selection is essential to maximize the clinical benefits of PVE. Computed tomography volumetry is used to calculate a standardized FLR and determine the need for preoperative PVE. Percutaneous PVE can be performed via the transhepatic ipsilateral or contralateral approaches, depending on operator preference. Several different embolic agents are available to the interventional radiologist, all with similar effectiveness in inducing hypertrophy. When an extended hepatectomy is planned, right PVE should include segment 4, in order to maximize FLR hypertrophy. Multiple studies have demonstrated the beneficial outcomes of PVE in both patients with healthy livers and with underlying liver diseases. Novel improvements to PVE should expand its scope to patients who were previously not candidates for the procedure.

Increase in the serum bile acid level predicts the effective hypertrophy of the nonembolized hepatic lobe after right portal vein embolization

BACKGROUND

The purpose of the present study was to investigate the clinical association between serum bile acid level changes and liver hypertrophy in portal vein embolization (PVE).

METHODS

In 31 patients, the serum total bile acid level was prospectively measured before and 1, 3, 5, 7, and 14 days after right PVE. Computed tomographic volumetry was performed before and 25.0 +/- 3.6 days after PVE.

RESULTS

Portal vein embolization induced the liver hypertrophy with a median increase in the left lobe volume (ILV) of 165 cm(3) and a median percentage ILV (%ILV) of 29%. Compared with the pretreatment level, the serum bile acid levels significantly increased on day 3 and day 14 after PVE (p = 0.017 and p = 0.003, respectively). In patients with greater hypertrophy after PVE (ILV > 165 cm(3) and %ILV > 30%), the increases in the bile acid level on day 3 were larger than that in those with lesser hypertrophy (p = 0.008 and p = 0.002, respectively). The increase on day 3 positively correlated with the ILV and %ILV (p = 0.003 and p = 0.004, respectively). The serum bile acid levels on day 3, 5, and 7 after PVE increased in patients with %ILV > 30% but not in those with %ILV < or = 30%.

CONCLUSIONS

Portal vein embolization increases the serum bile acid level in patients with effective liver hypertrophy in the nonembolized lobe. The increase on day 3 is a useful predictor of effective hypertrophy of the nonembolized lobe. Thus, bile acid signaling may be important for liver regeneration post-PVE.

Hilar cholangiocarcinoma: current management

OBJECTIVE

To review the literature with regard to outcome of surgical management for hilar cholangiocarcinoma (Klatskin tumor).

BACKGROUND

Hilar cholangiocarcinoma is a rare tumor with a poor prognosis. Surgical resection provides the only possibility for cure. Advances in hepatobiliary imaging and surgical strategies to treat this disease have resulted in improved postoperative outcomes.

METHODS

We performed a review of the English literature on hilar cholangiocarcinoma from 1990 to 2007. This review included preoperative evaluation, surgical techniques, issues and controversies in management, prognostic variables, and considerations for future directions.

RESULTS

Complete resection remains the most effective and only potentially curative therapy for hilar cholangiocarcinoma. Negative resection margins are associated with improved outcomes, and major hepatic resections have enhanced the likelihood of R0 resection. Portal vein embolization may be indicated in selected patients before extensive hepatic resection. Staging laparoscopy should be considered to detect occult metastatic disease. Orthotopic liver transplantation might be applicable for a highly selected subgroup.

CONCLUSIONS

Surgical resection including major hepatic resection remains the mainstay of treatment of hilar cholangiocarcinoma. Additional evidence is needed to fully define the role of orthotopic liver transplantation. Improvements in adjuvant therapy are essential for improving long-term outcome.

Preoperative right portal vein embolisation: indications and results

PURPOSE

The purpose of this retrospective study was to evaluate the efficacy of right portal vein embolisation (PVE) in inducing contralateral liver hypertrophy before extended hepatectomy.

MATERIALS AND METHODS

Twenty-six consecutive patients, 14 with liver metastases (ten from colorectal cancer; four from carcinoid tumours) and 12 with biliary cancers (ten Klatskin tumours; one gallbladder tumour; one intrahepatic cholangiocarcinoma) with insufficient predicted future remnant liver (FRL) underwent right PVE to induce hypertrophy of the contralateral hemiliver prior to surgical resection. Total liver volume, tumour volume and FRL volume were calculated on a 3D workstation. The ratio of the FRL to the total functional liver volume was <30% in all patients.

RESULTS

The FRL volume increased by 5%-25% (15% on average) after right PVE in patients with liver metastases and by 9%-19% (14% on average) in patients with biliary cancers. In all patients, the ratio of FRL to functional liver volume was >or=30% after right PVE. No postoperative deaths due to severe liver failure occurred in the 20 patients who underwent extended hepatectomy.

CONCLUSIONS

Right PVE extends the indications for hepatectomy in patients with liver metastases and those with biliary cancers who have an insufficient potential hepatic functional reserve.

Feasibility of laparoscopic portal vein ligation prior to major hepatectomy

BACKGROUND

Patients noted to have an inadequate future liver remnant on pre operative volumetric assessment are considered to be candidates for portal vein embolization (PVE). A subset of patients undergo laparoscopic intervention prior to PVE for staging purposes or to address the primary in Stage IV colon cancer. These patients usually undergo PVE as a subsequent additional procedure by the transhepatic route. The aim of this study was to assess the feasibility of portal vein ligation by the laparoscopic approach in suitable patients.

MATERIALS AND METHODS

A retrospective review of a prospectively maintained database was performed to identify patients that underwent laparoscopic portal vein ligation (LPVL). The demographic, clinical, radiographic, operative and volumetric details were collected to determine the feasibility of portal vein ligation.

RESULTS

A total of nine patients underwent LPVL as part of a two stage procedure in preparation for subsequent major hepatectomy. With a median age of 67 yrs, the diagnoses included: colorectal metastasis (five patients), cholangiocarcinoma (three patients) and hepatocellular carcinoma (one patient). The ligation involved the right portal vein in all and was performed with silk ligature (seven patients) and clips (two patients). Volumetric data was available in six patients which showed a mean increase from 209.1 cc+/-97.76 to 495.83 cc+/-310.91 (increase by 181.5%) In two patients, inadequate hypertrophy mandated later embolization by percutaneous technique. Five patients underwent subsequent major hepatic resection as planned. The remaining four patients were noted to have progression of disease that precluded the planned procedure. There were no complications associated with LPVL.

CONCLUSIONS

LPVL is feasible and can be safely performed. In a select group of patients, it may be considered as an alternative to subsequent embolization and thereby potentially absolve the need for an additional procedure with its attendant complications.

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.

Preoperative contralateral portal vein embolization before major hepatic resection is a safe and efficient procedure: a large single institution experience

BACKGROUND

The aim of this study was to report the results of preoperative contralateral portal vein embolization (PVE) performed in a single institution.

METHODS

Between January 1997 and March 2006, 146 patients requiring a right or extended right hepatectomy for primary or secondary liver tumors underwent contralateral PVE when the future remnant liver volume (FRL) was less than 30% of total liver. Liver volumes and hepatic function were evaluated before and after PVE.

RESULTS

Contralateral PVE was performed successfully in 145 patients. In one patient, the catheterization of the left portal branch failed. Complications occurred in 14 patients (10%) including a transitory fever (n = 9), a parenchymal hematoma (n = 1), a mild hemoperitoneum (n = 1), a mesenterico-portal venous thrombosis (n = 1), a pulmonary embolism (n = 1) and a systemic sepsis (n = 1). The prothrombin ratio and the platelet count were significantly lower 3 days after PVE. Insufficient hypertrophy of the FRL was observed in 8 patients, malignant disease progression in 15, and both insufficient hypertrophy and disease progression in 4. The hypertrophy rate of the FRL 4 to 8 weeks after PVE was 47.7 +/- 31.9%. Pathological type of the liver tumor, cirrhosis, diabetes mellitus, and chemotherapy did not affect the volume of the left liver hypertrophy. However, the time required to achieve an adequate liver hypertrophy was significantly shorter in patients with normal liver. One-hundred and fourteen patients (78.6%) subsequently underwent hepatic resection.

CONCLUSIONS

The results suggest that contralateral PVE is a safe and efficient procedure inducing adequate hypertrophy of the FRL before major liver resection.

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.

Preoperative Portal Vein Embolization and Surgical Resection in Patients with Hepatocellular Carcinoma and Small Future Liver Remnant Volume: Comparison with Transarterial Chemoembolization

BACKGROUND

Preoperative portal vein embolization (PVE) increases the future liver remnant (FLR) volume, thus enabling surgical resection in patients with small FLR volume. It is unclear, however, if this approach can enhance survival in patients with hepatocellular carcinoma (HCC). We therefore compared the outcomes of preoperative PVE and surgical resection with transarterial chemoembolization (TACE).

METHODS

Changes in FLR volumes were analyzed in 32 HCC patients who underwent preoperative PVE and surgical resection. Long-term outcomes were compared with 64 TACE-treated patients matched for gender, Child-Turcotte-Pugh class, tumor size and number, serum alpha-fetoprotein levels, and UICC stage.

RESULTS

In the PVE group, the baseline ratio of FLR/total estimated liver volumes (TELV) was 27.6 +/- 7.2%. Following PVE, FLR volume increased 34% (336.5 vs 449.4 mL, P < .001) and the ratio of FLR/TELV increased from 27.6 +/- 7.2 to 36.9 +/- 8.1% (P < .001). There was no mortality associated with PVE or surgical resection. The 5-year survival rate was significantly higher in the PVE group than in the TACE group (71.9% vs 45.6%, P = .03). Multivariate analysis showed that treatment modality was an independent predictive factor for survival (odds ratio 2.05, 95% confidence interval 1.01-4.16, P = .046).

CONCLUSIONS

Preoperative PVE enables surgical resection in HCC patients with small FLR volume and improves patient survival compared with TACE.

Liver regeneration: mechanisms, mysteries and more

BACKGROUND

Liver regeneration remains a fascinating topic, still partly clouded to many as to the exact cellular and molecular mechanisms that bring about this phenomenon. It is an area, therefore, of active research today. This review looks at the recent published reports that have led to a greater understanding of this process.

METHODS

A database search was carried out on Medline search using the terms liver regeneration with no linguistic limitations from 1966 to 2006.

RESULTS

There are two randomized controlled trials on the topic and most data and information have come from experimental studies in animals.

CONCLUSION

Liver regeneration is a complex, tightly controlled process involving many inflammatory cells growth factors and hormones. More information about it is awaited in studies on humans.

Sequential arterial and portal vein embolizations before right hepatectomy in patients with cirrhosis and hepatocellular carcinoma

BACKGROUND

Selective transarterial chemoembolization (TACE) and portal vein embolization (PVE) could improve the rate of hypertrophy of the future liver remnant (FLR) in patients with chronic liver disease. This study evaluated the feasibility and efficacy of this combined procedure.

METHODS

Between November 1998 and October 2004, 36 patients with cirrhosis and hepatocellular carcinoma underwent right hepatectomy after PVE. Additional TACE preceded PVE by 3-4 weeks in 18 patients (TACE+PVE group) and the remaining 18 patients had PVE alone (PVE group).

RESULTS

PVE was well tolerated in all patients. The mean increase in percentage FLR volume was significantly higher in the TACE+PVE group than in the PVE group (mean(s.d.) 12(5) versus 8(4) percent; P=0.022). The rate of hypertrophy was more than 10 percent in 12 patients in the TACE+PVE group and in five who had PVE alone (P=0.044). Duration of surgery, blood loss, incidence of liver failure and mortality (two patients in each group) were similar in the two groups. None of the 17 patients with an increase in FLR volume of more than 10 percent died, whereas there were four deaths among 19 patients with a smaller increase. The incidence of complete tumour necrosis was significantly higher in the TACE+PVE group (15 of 18 versus one of 18; P<0.001), with a higher 5-year disease-free survival rate (37 versus 19 percent; P=0.041).

CONCLUSION

Sequential TACE and PVE before operation increases the rate of hypertrophy of the FLR and leads to a high rate of complete tumour necrosis associated with longer recurrence-free survival.