Serum HGF and TGF-beta1 levels after right portal vein embolization

Negative impact of chemotherapy on kinetic growth rate of the future liver remnant if applied following PVE or ALPPS

PURPOSE

Modern liver surgery has improved the percentage of potentially resectable malignant tumors. However, if the future liver remnant is small, patients remain at risk of developing postoperative liver failure. Thus, the future liver remnant must be increased, while at the same time, the primary tumor may have to be controlled by chemotherapy. To address this conflict, we retrospectively analyzed the changes in hypertrophy before and after Associating Liver Partition with Portal vein ligation for Staged hepatectomy (ALPPS) or Portal Vein Embolization (PVE), with or without parallel systemic chemotherapy.

MATERIALS AND METHODS

We retrospectively analysed 172 patients (54 female and 118 male), treated with ALPPS in 90 patients (median age 61 years [Q1, Q3: 52,71]) and with PVE in 82 patients (median age 66 years [Q1, Q3: 56,73]). The median control interval was 4.9 [Q1, Q3: 4.0, 6.0] weeks after the PVE, and 2.6 [Q1, Q3: 1.6, 5.8] weeks after ALPPS step 1.

RESULTS

The overall kinetic growth rate (median) for the entire group was 0.02 (2%) per week. When systemic chemotherapy was administered prior to intervention, the kinetic growth rate of these treated patients (vs. untreated) exhibited a median of 0.020 [Q1, Q3: 0.011, 0.067] compared to 0.024 [Q1, Q3: 0.013, 0.041] (p = 0.949). When chemotherapy was administered after the PVE/ ALPPS treatment, the kinetic growth rate declined from a median of 0.025 [Q1, Q3: 0.013, 0.053] to 0.011 [Q1, Q3: 0.007, 0.021] (p = 0.005). Subgroup analysis showed statistically significant effects only in the PVE group (median ALPPS -45% (p = 0.157), PVE -47% (p = 0.005)).

CONCLUSION

This retrospective analysis indicated that systemic chemotherapy given after PVE/ the first step of the ALPPS procedure, i.e., the growth phase, has a negative effect on the kinetic growth rate.

Oncological benefits of portal vein embolization for patients with hepatocellular carcinoma

Portal vein embolization (PVE) for hepatocellular carcinoma (HCC) was first introduced in 1986 and has been continuously developed throughout the years. Basically, PVE has been applied to expand the indication of liver resection for HCC patients of insufficient future liver remnant. Importantly, PVE can result in tumor progression in both embolized and non-embolized livers; however, long-term survival after liver resection following PVE is at least not inferior compared with liver resection alone despite the smaller future liver remnant volume. Five-year disease-free survival and 5-year overall survival were 17% to 49% and 12% to 53% in non-PVE patients, and 21% to 78% and 44% to 72% in PVE patients, respectively. At present, it has proven that PVE has multiple oncological advantages for both surgical and nonsurgical treatments. PVE can also enhance the anticancer effects of transarterial chemoembolization and can avoid intraportal tumor cell dissemination. Additional interventional transarterial chemoembolization and hepatic vein embolization as well as surgical two-stage hepatectomy and associated liver partition and portal vein ligation for staged hepatectomy can enhance the oncological benefit of PVE monotherapy. Taken together, PVE is an important treatment which we recommend for listing in the guidelines for HCC treatment strategies.

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

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

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

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

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

Liver Resection After Selective Internal Radiation Therapy with Yttrium-90: Safety and Outcomes

Introduction

Selective internal radiotherapy (SIRT) with yttrium-90 (Y-90) is an intra-arterial therapy for hepatic malignancy in patients who are unsuitable for surgical resection. This treatment is considered palliative, although some patients can demonstrate a response that is adequate to facilitate surgical resection with curative intent.

Methods

All patients who underwent liver resection post SIRT were reviewed. Data gathered included patient demographics, tumor type, surgical details, and post-operative outcomes.

Results

Twelve patients underwent SIRT followed by liver resection (7 males and 5 females). Pathologies were hepatocellular carcinoma (n = 5), metastatic colorectal cancer (n = 5), and neuroendocrine tumor (n = 2). Lesional response (size, volume, and RECIST (response evaluation criteria in solid tumors)) was calculated and where appropriate functional liver remnant (FLR) is presented. Mean FLR increase was 264cm³ (range − 123 to 909), and all cases demonstrated a partial response according to RECIST with a mean largest lesion volume reduction of 475cm³ (range 14–1632). No post-SIRT complications were noted. Hepatectomy occurred at a mean of 322 days from SIRT treatment. Ninety-day morbidity was 67% (n = 6), complications post-surgery were analyzed according to the Clavien-Dindo classification scale; a total of 15 events occurred in 6 patients. Ninety-day mortality of 11% (n = 1).

Conclusion

In selected cases, liver resection is possible post SIRT. As this can represent a potentially curative option, it is important to reconsider resection in the follow-up of patients undergoing SIRT. Post-operative complications are noted following major and extended liver resection. Therefore, further studies are needed to improve patient selection.

Portal Vein Embolization: Correlation of Future Liver Remnant Hypertrophy to Type of Embolic Agent Used

Purpose

The purpose of this study was to compare the effectiveness of portal vein embolization (PVE) with different embolic agents used at our centre. Specifically, the effectiveness of N-butyl cyanoacrylate (NBCA) glue is compared with that of polyvinyl alcohol (PVA) particles.

Methods

We performed a retrospective chart review of all patients (N = 77) who underwent PVE at our institution over a 5-year period. Pre- and postprocedural computed tomography or magnetic resonance imaging, when available, were used to measure the volume of total liver volume and future liver remnant (FLR). The absolute values obtained were used to calculate percentage of FLR. The growth in FLR was determined 4–6 weeks after PVE. Technical details of the procedure including the type and amount of embolic agent used were obtained from the chart reviews, electronic patient records, and radiology reports. Statistical analysis was performed using Kruskal-Wallis test, Wilcoxon rank sum test, and the Spearman correlation coefficient with post hoc analysis. Results are expressed as mean ± SD ( P < .05 considered statistically significant).

Results

NBCA (n = 29) produced a mean change in FLR of 14.8% compared with 9.3% for PVA particles (n = 24; P = .007). Mean change in FLR was 10.1% in the group where a combination of NBCA and PVA particles was used (n = 24). The effect of glue volume and glue-to-lipiodol ratio on the outcome was not found to be statistically significant ( P = .5 and .7, respectively).

Conclusions

We conclude that NBCA glue is a better embolic agent than PVA particles in inducing liver hypertrophy.

Thrombospondin-1 expression may be implicated in liver atrophic mechanism due to obstructed portal venous flow

AIM

Liver is an amazing organ that can undergo regenerative and atrophic changes inversely, depending on blood flow conditions. Although the regenerative mechanism has been extensively studied, the atrophic mechanism remains to be elucidated.

METHODS AND RESULTS

To assess the molecular mechanism of liver atrophy due to reduced portal blood flow, we analyzed the gene expressions between atrophic and hypertrophic livers induced by portal vein embolization in three human liver tissues using microarray analyses. Thrombospondin (TSP)-1 is an extracellular protein and a negative regulator of liver regeneration through its activation of the transforming growth factor-β/Smad signaling pathway. TSP-1 was extracted as the most upregulated gene in atrophic liver compared to hypertrophic liver due to portal flow obstruction in human. Liver atrophic and hypertrophic changes were confirmed by HE and proliferating cell nuclear antigen staining and terminal deoxynucleotidyl transferase-mediated digoxigenin-dUTP nick-end labeling. In an in vivo model with portal ligation, TSP-1 and phosphorylated Smad2 expression were continuously induced at 6 h and thereafter in the portal ligated liver, whereas the induction was transient at 6 h in the portal non-ligated liver. Indeed, while cell proliferation represented by proliferating cell nuclear antigen expression at 48 h was induced in the portal ligated liver, the sinusoidal dilatation and hepatocyte cell death with terminal deoxynucleotidyl transferase-mediated digoxigenin-dUTP nick-end labeling was detectable at 48 h in the portal ligated liver.

CONCLUSIONS

Obstructed portal flow induces persistent TSP-1 expression and transforming growth factor-β/Smad signal activation in atrophic liver. Thrombospondin-1 may be implicated in the liver atrophic change due to obstructed portal flow as a pro-atrophic factor.

Limits of and Complications after Embolization of the Hepatic Artery and Portal Vein to Induce Segmental Hypertrophy of the Liver: A Large Mini-Pig Study

Background: The aim of this study was to compare arterial embolization (AE) with portal vein embolization (PVE) for the induction of segmental hypertrophy regarding procedural efficacy, safety and outcome. Methods: A total of 29 mini pigs were subjected to PVE, AE or assigned to the sham (SO) group. Correspondingly, 75% of the hepatic artery or portal vein branches were embolized. Growth and atrophy of the liver lobes, calculating the liver-to-body weight index (LBWI), laboratory data, arteriography, portography, Doppler ultrasound (US) and histopathology were analyzed. Results: After PVE, 2 animals had to be excluded due to technical problems. After AE, 4 animals had to be excluded because of technical problems and early sacrifice. Postprocedural US demonstrated effective AE and PVE of the respective lobes. Four weeks after PVE, portography showed a slow refilling of the embolized lobe by collateral portal venous vessels. Four weeks after AE, arteriography revealed a slight revascularization of the embolized lobes by arterial neovascularization. Segmental AE led to extensive necrotic and inflammatory alterations in the liver and bile duct parenchyma. Significant hypertrophy of the non-embolized lobe was only noted in the PVE group (LBWI: 0.91 ± 0.28%; p = 0.001). There was no increase in the non-embolized lobe in the AE (LBWI: 0.45 ± 0.087%) and SO group (LBWI: 0.45 ± 0.13%). Conclusion: PVE is safe and effective to induce segmental hypertrophy. Portal reperfusion by collateral vessels may limit hypertrophy. AE did not increase the segmental hepatic volume but carries the risk of extensive necrotic inflammatory damage.

Portal Vein Embolization Followed by Right-Side Hemihepatectomy for Hepatocellular Carcinoma Patients: A Japanese Multi-Institutional Study

BACKGROUND

Portal vein embolization (PVE) is useful to expand the indications of major hepatectomy; however, its oncologic effects are not fully understood. This study aimed to confirm the efficacy of preoperative PVE for hepatocellular carcinoma patients.

STUDY DESIGN

Between 2000 and 2012, five hundred and ten patients with hepatocellular carcinoma undergoing right-side hemihepatectomy were enrolled (PVE group, n = 162 and non-PVE group, n = 348). To equalize background factors, one-to-one propensity case-matched analysis and multivariate analysis were performed. Short- and long-term outcomes were evaluated.

RESULTS

Propensity score-matched patients, 148 in each group, were selected. The percentage of resected liver volume on admission was significantly greater in the PVE group (60.5% vs 48.3%; p < 0.001), but decreased considerably after PVE, from 60.5% to 50.3% (p < 0.001). The 5-year cumulative recurrence-free survival (36.4% vs 35.3%) and overall survival (58.6% vs 52.8%) rates were comparable. Extrahepatic recurrences were less common in the PVE group (18.1% vs 38.8%; p = 0.004). Independent prognostic factors for recurrence-free survival were morbidity (hazard ratio [HR] = 1.56), multiple tumors (HR = 1.97), red cell concentrate administration (HR = 1.57), older age (HR = 2.09), and massive portal invasion (HR = 2.33); and those for overall survival were morbidity (HR = 2.37), multiple tumors (HR = 1.71), and massive hepatic venous invasion (HR = 3.49).

CONCLUSIONS

Even though hepatocellular carcinoma patients who underwent preoperative PVE and right-side hemihepatectomy had a significantly larger resected liver volume on admission, they have a comparable long-term prognosis as patients with up front hepatectomy. In addition, PVE might decrease extrahepatic recurrences.

De Novo Donor-Specific HLA Antibody Formation in Two Patients With Crigler-Najjar Syndrome Type I Following Human Hepatocyte Transplantation With Partial Hepatectomy Preconditioning

Clinical hepatocyte transplantation is hampered by low engraftment rates and gradual loss of function resulting in incomplete correction of the underlying disease. Preconditioning with partial hepatectomy improves engraftment in animal studies. Our aim was to study safety and efficacy of partial hepatectomy preconditioning in clinical hepatocyte transplantation. Two patients with Crigler-Najjar syndrome type I underwent liver resection followed by hepatocyte transplantation. A transient increase of hepatocyte growth factor was seen, suggesting that this procedure provides a regenerative stimulus. Serum bilirubin was decreased by 50%, and presence of bilirubin glucuronides in bile confirmed graft function in both cases; however, graft function was lost due to discontinuation of immunosuppressive therapy in one patient. In the other patient, serum bilirubin gradually increased to pretransplant concentrations after ≈600 days. In both cases, loss of graft function was temporally associated with emergence of human leukocyte antigen donor-specific antibodies (DSAs). In conclusion, partial hepatectomy in combination with hepatocyte transplantation was safe and induced a robust release of hepatocyte growth factor, but its efficacy on hepatocyte engraftment needs to be evaluated with additional studies. To our knowledge, this study provides the first description of de novo DSAs after hepatocyte transplantation associated with graft loss.

Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS): a new strategy to increase resectability in liver surgery

BACKGROUND

Partial hepatectomy with clear surgical margins is the main curative treatment for hepatic malignancies. The safety of liver resection, to a great extent, depends on the volume of future liver remnant. This manuscript reviews some important strategies that have been developed to increase resectability for patients with borderline volume of future liver remnant, particularly associating liver partition and portal vein ligation for staged hepatectomy (ALPPS).

METHODS

To identify potentially relevant articles, we searched Medline and PubMed from January 2010 to December 2013 using the keywords "Associating liver partition and portal vein ligation for staged hepatectomy", "ALPPS", "portal vein embolization", "future liver remnant", "liver hypertrophy", and "liver failure". A number of references from the key articles were also cited. There were no exclusion criteria for published information to the topics.

RESULTS

Portal vein ligation (PVL) or embolization (PVE) are traditional approaches to induce liver hypertrophy of the future liver remnant (FLR) prior to hepatectomy in primarily non-resectable liver tumors. However, about 14 percent of patients fail to this approach. Adequate hypertrophy of the FLR using PVL or PVE generally takes more than four weeks. ALPPS can induce rapid growth of the FLR, which is more effective than by portal vein embolization or occlusion alone. Reportedly, the hypertrophy extent of FLR was 40%-80% within 6-9 days in contrast to approximately 8%-27% within 2-60 days by PVL/PVE. However, ALPPS was reported to have high operative morbidity (16%-64% of patients), mortality (12%-23% of patients) and bile leakage rates. Bile leakage and sepsis remain a major cause of morbidity, and the main cause of mortality includes hepatic insufficiency.

CONCLUSION

ALPPS has emerged as a new strategy to increase resectability of hepatic malignancies. Due to high morbidity and mortality rates of ALPPS procedure, the surgical candidates should be selected carefully. Moreover, there are very limited available evidence for its technical feasibility, safety and oncological outcome which are needed for further evaluation in larger scale of studies.

Pathological changes, TGF-β1 expression, and the effects of hepatocyte growth factor in 5/6 nephrectomized rats

Several studies have shown that hepatocyte growth factor (HGF) ameliorates chronic renal failure, but its mechanism of action is unclear. This study was designed to test the delivery of HGF in the PCI-neo vector, using the 5/6 nephrectomized rat as a model for chronic renal failure, and to confirm that this protective function is associated with decreased protein expression of transforming growth factor-beta1 (TGF-β1). Rats were randomly divided into the following groups: Control (untreated), PCI-neo (vector control), 5/6 nephrectomy, and PCI-neo-HGF. Rats were sacrificed at both the fifth and ninth week after 5/6 nephrectomy. Kidney specimens were used for pathological examination (hematoxylin-eosin staining), and detection of TGF-β1 protein (Western blot and immunohistochemistry) expression. Blood urea nitrogen, serum creatinine, and 24-h urinary protein excretion (UPE) were increased, renal interstitium was seriously injured, and TGF-β1 protein expression was elevated in 5/6 nephrectomized rats compared to control rats at either time point. Red blood cell and hemoglobin levels decreased in the ninth week after 5/6 nephrectomy. PCI-neo-HGF expression ameliorated the aforementioned changes and decreased TGF-β1 expression, not only in the fifth week, but also in the ninth week after surgery. The process of renal injury in the 5/6 nephrectomized rat was consistent with that of chronic renal failure. The increase in TGF-β1 expression was maintained after 5/6 nephrectomy. HGF relieved chronic renal failure, this protection was associated with down-regulation of TGF-β1 protein expression, and the protective effects were long-term and stable after 5/6 nephrectomy.

Autologous bone marrow-derived mesenchymal stem cell transplantation promotes liver regeneration after portal vein embolization in cirrhotic rats

BACKGROUND

Preexisting cirrhosis usually leads to an inadequate and delayed regeneration of the future liver remnant (FLR) after portal vein embolization (PVE). Bone marrow-derived mesenchymal stem cells (BMSC) are promising candidates for therapeutic applications in liver diseases. In this study, the efficacy of autologous BMSCs transplantation to promote FLR regeneration was investigated in a rat cirrhotic model.

METHODS

Autologous BMSCs were expanded and labeled with PKH26, and then were injected immediately into nonembolized lobes after PVE through portal vein in cirrhotic rat. At 7, 14, and 28 d after this, liver weight and Ki-67 labeling index were measured, and blood analysis was performed. Cirrhotic degree of FLR was assessed by hydroxyproline content assay and histopathology. Gene expressions of vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF), interleukin-10 (IL-10), and matrix metalloproteinase-9 (MMP-9) were detected with real-time reverse transcriptase-polymerase chain reaction. Distribution and hepatocyte differentiation of BMSCs in FLR were determined by confocal microscopy.

RESULTS

Autologous BMSCs significantly increased the FLR weight ratio to the total liver and the Ki-67 labeling index, and serum albumin levels were significantly higher and total bilirubin levels were significantly lower in the BMSCs group compared with the controls without BMSCs transplantation 14 and 28 d post-PVE. BMSCs significantly decreased the hydroxyproline content and collagen accumulation, up-regulated the expressions of HGF, IL-10, VEGF, and MMP-9 28 d post-PVE, and expressed hepatocyte-specific markers, such as α-fetoprotein, cytokeratin 18, and albumin in a time-dependent manner in FLR.

CONCLUSIONS

Autologous BMSCs can differentiate into hepatocyte and promote FLR regeneration after PVE in cirrhotic liver, which may be through improving local microenvironment by decreasing cirrhosis, up-regulating the gene expressions of VEGF, HGF, IL-10, and MMP-9.

Prognostic importance of some clinical and therapeutic factors for the effect of portal vein embolization in patients with primarily inoperable colorectal liver metastases

INTRODUCTION

Portal vein embolization (PVE) may increase the resectability of liver metastases. However, the problem of PVE is insufficient growth of the liver or tumor progression in some patients. The aim of this study was to evaluate the significance of commonly available clinical factors for the result of PVE.

MATERIAL AND METHODS

Portal vein embolization was performed in 38 patients with colorectal liver metastases. Effects of age, gender, time between PVE and liver resection, oncological therapy after PVE, indocyanine green retention rate test, synchronous, metachronous and extrahepatic metastases, liver volume before and after PVE, increase of liver volume after PVE and the quality of liver parenchyma before PVE on the result of PVE were evaluated.

RESULTS

Liver resection was performed in 23 (62.2%) patients within 1.3 ±0.4 months after PVE. Tumor progression occurred in 9 (23.7%) patients and 6 (15.8%) patients had insufficient liver hypertrophy. Significant clinical factors of PVE failure were number of liver metastases (cut-off - 4; odds ratio - 4.7; p < 0.03), liver volume after PVE (cut-off 1000 cm(3); odds ratio - 5.1; p < 0.02), growth of liver volume after PVE (cut-off 150 cm(3); odds ratio - 18.7; p < 0.002), oncological therapy administered concomitantly with PVE (p < 0.003).

CONCLUSIONS

Negative clinical factors of resectability of colorectal cancer liver metastases after PVE included more than four liver metastases, liver volume after PVE < 1000 cm(3), growth of the contralateral lobe by less than 150 cm(3) and concurrent oncological therapy.

External biliary drainage and liver regeneration after major hepatectomy

BACKGROUND

Bile acid signalling and farnesoid X receptor activation are assumed to be essential for liver regeneration. This study was designed to investigate the association between serum bile acid levels and extent of liver regeneration after major hepatectomy.

METHODS

Patients who underwent left- or right-sided hemihepatectomy between 2006 and 2009 at the authors' institution were eligible for inclusion. Patients were divided into two groups: those undergoing hemihepatectomy with external bile drainage by cystic duct tube (group 1) and those having hemihepatectomy without drainage (group 2). Serum bile acid levels were measured before and after hepatectomy. Computed tomography was used to calculate liver volume before hepatectomy and remnant liver volume on day 7 after surgery.

RESULTS

A total of 46 patients were enrolled. Mean(s.d.) serum bile acid levels on day 3 after hemihepatectomy were significantly higher in group 2 than in group 1 (11·6(13·5) versus 2·7(2·1) µmol/l; P = 0·003). Regenerated liver volumes on day 7 after hepatectomy were significantly greater in group 2 138·1(135·9) ml versus 40·0(158·8) ml in group 1; P = 0·038). Liver regeneration volumes and rates on day 7 after hemihepatectomy were positively associated with serum bile acid levels on day 3 after hemihepatectomy (P = 0·006 and P < 0·001 respectively). The incidence of bile leakage was similar in the two groups.

CONCLUSION

Initial liver regeneration after major hepatectomy was less after biliary drainage and was associated with serum bile acid levels. External biliary drainage should be used judiciously after liver resection.

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.

Liver hypertrophy and accelerated growth of implanted tumors in nonembolized liver of rabbit after left portal vein embolization

BACKGROUND

Portal vein embolization (PVE) has become a standard preoperative procedure to promote hypertrophy of the future remnant liver to reduce postoperative liver failure. Whether PVE accelerates tumor growth is still controversial. We developed a left PVE procedure and investigated its effect on liver hypertrophy and tumor growth in a rabbit liver tumor model.

MATERIALS AND METHODS

VX2 tumors were implanted in both the external left and right middle lobe (the bilateral group) or in the external left lobe only (the unilateral group) of rabbit liver. Both groups were further divided into a PVE or a sham/control group. Tumor volume and tumor growth rate as volume relative increase were determined by ultrasound. Liver volume-to-body weight index, an index for liver volume, was compared. Serum HGF was measured by ELISA.

RESULTS

In the bilateral PVE group, tumor volume and relative increase value in the nonembolized lobe were significantly (71% and 65%, respectively) greater than those in the control group at 5 d post-PVE. In the unilateral PVE group, liver volume-to-body weight index of the nonembolized lobes was significantly increased by 17%. Increase of serum HGF level after PVE was correlated well with both tumor growth and liver hypertrophy.

CONCLUSIONS

Left PVE promoted both the growth of implanted tumors and liver hypertrophy in the nonembolized liver, in which serum HGF might play an important role.