Increased safety by two-stage hepatectomy with preoperative portal vein embolization in rats

Ipsilateral access portal venous embolization (PVE) for preoperative hypertrophy exhibits low complication rates in Clavien-Dindo and CIRSE scales

Background

Portal venous embolization (PVE) is a minimal invasive preoperative strategy that aims to increase future liver remnant (FLR) in order to facilitate extended hemihepatectomy. We analyzed our data retrospectively regarding complications and degree of hypertrophy (DH).

Methods: 88 patients received PVE either by particles / coils (n = 77) or by glue / oil (n = 11), supported by 7 right hepatic vein embolizations (HVE) by coils or occluders. All complications were categorized by the Clavien- Dindo (CD) and the CIRSE classification.

Results

In 88 patients (median age 68 years) there was one intervention with a biliary leak and subsequent drainage (complication grade 3 CD, CIRSE 3), two with prolonged hospital stay (grade 2 CD, grade 3 CIRSE) and 13 complications grade 1 CD, but no complications of grade 4 or higher neither in Clavien- Dindo nor in CIRSE classification. The median relative increase in FLR was 47% (SD 35%). The mean pre-intervention standardized FLR rose from 23% (SD 10%) to a post-intervention standardized FLR of 32% (SD 12%). The degree of hypertrophy (DH) was 9,3% (SD 5,2%) and the kinetic growth rate (KGR) per week was 2,06 (SD 1,84).

Conclusion

PVE and, if necessary, additional sequential HVE were safe procedures with a low rate of complications and facilitated sufficient preoperative hypertrophy of the future liver remnant.

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.

Changes in liver stiffness on real-time tissue elastography before and after occlusion of spontaneous portosystemic shunts

PURPOSE

This study was conducted to evaluate changes in liver stiffness, volume, and function before and after occlusion of spontaneous portosystemic shunt.

MATERIALS & METHODS

Twenty-four patients (13 men and 11 women) with a mean age of 68.2 years±10.1 (SD) (age range, 49-82 years) underwent percutaneous occlusion of spontaneous portosystemic shunt because of gastric varices (n=17) or hepatic encephalopathy (n=7) from March 2011 to June 2013. The liver fibrosis index indicating liver stiffness was calculated by using ultrasound elastography before and after shunt occlusion. Liver volume and liver profile were also evaluated.

RESULTS

Spontaneous portosystemic shunt occlusion was uneventfully performed in all patients. The mean liver fibrosis index was significantly decreased from 2.7±1.0 before shunt occlusion to 2.0±0.9 (P<0.001) at 1 month, 2.2±1.0 at 3 months (P=0.004), and 1.6±0.7 at 6 months (P=0.001) afterwards. A significant increase in the liver volume was observed from 1035.3±340.1mL before shunt occlusion to 1116.8±298.4mL (P=0.006) at 1 month and 1174.2±354.1mL (P<0.001) at 3 months afterwards. Significant improvement in the Child-Pugh score was also found at 1 month (6.2±1.4, P<0.001), 3 months (6.5±1.1, P=0.022), and 6 months (6.0±0.9, P=0.004) after shunt occlusion as compared with that (7.2±1.9) before.

CONCLUSION

The liver stiffness decreases along with an increase in liver volume and improvement in liver function after spontaneous portosystemic shunt occlusion.

Mechanistic insights of rapid liver regeneration after associating liver partition and portal vein ligation for stage hepatectomy

AIM

To highlight the potential mechanisms of regeneration in the Associating Liver Partition and Portal vein ligation for Stage hepatectomy models (clinical and experimental) that could unlock the myth behind the extraordinary capability of the liver for regeneration, which would help in designing new therapeutic options for the regenerative drive in difficult setup, such as chronic liver diseases. Associating Liver Partition and Portal vein ligation for Stage hepatectomy has been recently advocated to induce rapid future liver remnant hypertrophy that significantly shortens the time for the second stage hepatectomy. The introduction of Associating Liver Partition and Portal vein ligation for Stage hepatectomy in the surgical armamentarium of therapeutic tools for liver surgeons represented a real breakthrough in the history of liver surgery.

METHODS

A comprehensive literature review of Associating Liver Partition and Portal vein ligation for Stage hepatectomy and its utility in liver regeneration is performed.

RESULTS

Liver regeneration after Associating Liver Partition and Portal vein ligation for Stage hepatectomy is a combination of portal flow changes and parenchymal transection that generate a systematic response inducing hepatocyte proliferation and remodeling.

CONCLUSION

Associating Liver Partition and Portal vein ligation for Stage hepatectomy represents a real breakthrough in the history of liver surgery because it offers rapid liver regeneration potential that facilitate resection of liver tumors that were previously though unresectable. The jury is still out though in terms of safety, efficacy and oncological outcomes. As far as Associating Liver Partition and Portal vein ligation for Stage hepatectomy -induced liver regeneration is concerned, further research on the field should focus on the role of non-parenchymal cells in liver regeneration as well as on the effect of Associating Liver Partition and Portal vein ligation for Stage hepatectomy in liver regeneration in the setup of parenchymal liver disease.

A novel rat model of liver regeneration: possible role of cytokine induced neutrophil chemoattractant-1 in augmented liver regeneration

Background

Liver resection is the mainstay of treatment for most of the liver tumors. Liver has a unique capability to restore the lost volume following resection, however, most of the primary tumors grow in a liver with preexisting parenchymal diseases and secondary tumors often present in multiple liver lobes precluding a safe curative resection. Two-stage hepatectomy and portal vein ligation (PVL) are used to achieve a safer future remnant liver volume (FRLV), however, these procedures take several weeks to achieve adequate FRLV. A recently introduced faster alternative two-stage hepatectomy, also know as associated liver partitioning and portal vein ligation for staged hepatectomy (ALPPS), produces a desirable FRLV in days.

Methods

To have an insight into the mechanism of ALPPS associated liver regeneration, we reproduced a rat model of ALPPS and compared the results with the PVL group.

Results

Our results convincingly showed an advantage of the ALPPS procedure over PVL group in terms of early regeneration, however, in 1-week time the amount of regeneration was comparable. An early regeneration in the ALPPS group coincided with an early entry of hepatocytes into the cell proliferation phase, a significant increase in portal pressure and increase in hepatic enzymes in the ALPPS group compared with the PVL group. According to the protein array evaluation of 29 cytokines/chemokines, cytokine induced neutrophil chemoattractant-1 had the highest expression whereas IL-6 had the highest fold (>6 vs PVL group) expression at the early phase of regeneration in the ALPPS group.

Conclusions

This unique rat model of ALPPS would help to improve our understanding about the liver generation process and also will help in further refinement of the ALPPS procedure for the clinical benefit.

Electronic supplementary material

The online version of this article (doi:10.1186/s13022-015-0020-3) contains supplementary material, which is available to authorized users.

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.

Two-stage hepatectomy: who will not jump over the second hurdle?

BACKGROUND

Two-stage hepatectomy uses compensatory liver regeneration after a first noncurative hepatectomy to enable a second curative resection in patients with bilobar colorectal liver metastasis (CLM).

OBJECTIVE

To determine the predictive factors of failure of two-stage hepatectomy.

METHOD

Between 2000 and 2010, 48 patients with irresectable CLM were eligible for two-stage hepatectomy. The planned strategy was a) cleaning of the left hepatic lobe (first hepatectomy), b) right portal vein embolisation and c) right hepatectomy (second hepatectomy). Six patients had occult CLM (n = 5) or extra-hepatic disease (n = 1), which was discovered during the first hepatectomy. Thus, 42 patients completed the first hepatectomy and underwent portal vein embolisation in order to receive the second hepatectomy. Eight patients did not undergo a second hepatectomy due to disease progression.

RESULTS

Upon univariate analysis, two factors were identified that precluded patients from having the second hepatectomy: the combined resection of a primary tumour during the first hepatectomy (p = 0.01) and administration of chemotherapy between the two hepatectomies (p = 0.03). An independent association with impairment to perform the two-stage strategy was demonstrated by multivariate analysis for only the combined resection of the primary colorectal cancer during the first hepatectomy (p = 0.04).

CONCLUSION

Due to the small number of patients and the absence of equivalent conclusions in other studies, we cannot recommend performance of an isolated colorectal resection prior to chemotherapy. However, resection of an asymptomatic primary tumour before chemotherapy should not be considered as an outdated procedure.

Improving outcome in patients undergoing liver surgery

Liver surgery is associated with many factors, which may affect outcome. Preoperative assessment of patient's general condition, resectability, and liver reserve are paramount for success. The Child-Pugh score and other scoring systems only partially enables to assess the risk associated with liver surgery. The presence of portal hypertension per se is a major risk factor for hepatectomy. Intraoperatively, any attempts should be made to minimize blood loss. Low central venous pressure and inflow occlusion best prevent bleeding. Ischemic preconditioning and intermittent clamping are routinely applied in many centers to protect against long periods of ischemia, although the mechanisms of protection remain unclear. In this review we describe recent advances in activated pathways associated with protection against ischemia. Postoperatively, the best factor impacting on outcome probably resides in experienced medical care particularly in the intensive care setting. Currently, no drug or gene therapy approaches has reached the clinic. The future relies on new insight into mechanisms of ischemia-reperfusion injury.

Recovery of hepatic function determined by cytochrome P450-dependent drug metabolism lags after compensatory hepatic volume changes after portal vein ligation in rats

BACKGROUND

Clinically, portal vein embolization has been proven to be useful as a preoperative treatment for major hepatic surgeries with impaired liver function. However, its effects on the metabolism and elimination of various drugs after portal vein embolization or ligation remain to be elucidated.

MATERIALS AND METHODS

A portal vein branch that perfuses the central and left lobes of the liver of male Wistar rat was ligated, and changes in the weights of ligated and nonligated lobules as well as hepatic levels and activities of cytochrome P450 (CYP) isoforms, such as CYP3A2 and CYP2C11, were determined. To evaluate in vivo the effect of PVL on hepatic drug metabolism, the narcotic activity (sleep time) of midazolam, a specific substrate for CYP3A2, was measured.

RESULTS

Although plasma levels of alanine aminotransferase and hepatic weight returned to basal levels at day 7 after the portal vein ligation, hepatic activities of CYP3A2 and CYP2C11 still remained low (53% and 54% of control levels, respectively), and returned to their initial levels after about day 14. The metabolism of midazolam was prolonged by approximately three times at day 7 after ligation and returned to basal levels at day 14.

CONCLUSIONS

Because hepatic CYP-dependent drug metabolism by CYP isoforms recovered more slowly than the apparent recovery of hepatic volume and plasma alanine aminotransferase levels, the therapeutics of drugs metabolized by the CYP isoforms should be used carefully in patients who receive major hepatectomy with portal vein branch embolization.

Portal vein embolization induces compensatory hypertrophy of remnant liver

AIM: To evaluate the effectiveness and safety of different portal vein branch embolization agents in inducing compensatory hypertrophy of the remnant liver and to offer a theoretic basis for clinical portal vein branch embolization.

METHODS: Forty-one adult dogs were included in the experiment and divided into four groups. Five dogs served as a control group, 12 as a gelfoam group, 12 as a coil-gelfoam group and 12 as an absolute ethanol group. Left portal vein embolization was performed in each group. The results from the embolization in each group using different embolic agents were compared. The safety of portal vein embolization (PVE) was evaluated by liver function test, computed tomography (CT) and digital subtraction angiography (DSA) of liver and portal veins. Statistical test of variance was performed to analyze the results.

RESULTS: Gelfoam used for PVE was inefficient in recanalization of portal vein branch 4 wk after the procedure. The liver volume in groups of coil-gelfoam and absolute ethanol increased 25.1% and 33.18%, respectively. There was no evidence of recanalization of embolized portal vein, hepatic dysfunction, and portal hypertension in coil-gelfoam group and absolute ethanol group.

CONCOUSION: Portal vein branch embolization using absolute ethanol and coil-gelfoam could induce atrophy of the embolized lobes and compensatory hypertrophy of the remnant liver. Gelfoam is an inefficient agent.

Gene expression profile analysis of regenerating liver after portal vein ligation in rats by a cDNA microarray system

AIMS

We assessed changes in gene expression of hypertrophied liver after portal vein ligation (PL) in a test group of rats compared to a control group, which had the same size liver but no PL.

METHODS

The portal veins of the left and median lobes in the test group were ligated in an initial operation. Four days after the PL, the liver volume of the posterior caudate lobe (5%) increased two-fold and comprised 10% of the liver. A 90% hepatectomy was then performed, leaving only the hypertrophied posterior caudate lobe, and leaving the normal anterior and posterior caudate lobes (10%) in the control (sham) group. A comparison of the expression profiles between two groups was performed using cDNA microarrays and the hepatic ATP level was measured.

RESULTS

The survival rate for the PL group was significantly higher than for the sham group at 4 days after the hepatectomy (56.3% and 26.7%, P < 0.05). Gene expression of cyclin D1, proliferating cell nuclear antigen, cyclin A and B was upregulated, and the cyclin-dependent kinase inhibitor was downregulated. Increases were observed in: (i) pyruvate dehydrogenase, the tricarboxylic acid cycle cycle regulator, (ii) acyl-CoA dehydrogenase, the oxidation regulator, and (iii) cytochrome oxidases, the oxidative phosphorylation regulator. Hepatic ATP concentration after hepatectomy was better maintained in the PL group than in the sham group (0.48 +/- 0.01 micromol/ml vs. 0.33 +/- 0.01 micromol/ml, P < 0.05).

CONCLUSION

The regenerating liver increased tolerance for extended hepatectomy compared to normal liver. It is believed that this is because the induced rapid regeneration of the remaining liver after hepatectomy increases ATP metabolism.

Sustained function in atrophying liver tissue after portal branch ligation in the rat

BACKGROUND

Preoperative segmental portal vein occlusion has become a common method to prevent liver failure after extended hepatic resection. To date, it is not elucidated whether atrophy by portal deprivation with concomitant contralateral regeneration leads to impaired liver function. We addressed this question by examining the expression of liver function proteins related to glucose homeostasis and acute-phase response in a corresponding animal model.

MATERIALS AND METHODS

Male Wistar rats were subjected to either portal branch ligation (PBL), partial hepatectomy (PH), or sham operation (SO). The mRNA expression and chronological distribution of glucose-6-phosphatase (G6P), glucagon receptor (GR), glceraldehyd-3-phosphate-dehydrogenase (GAPDH), albumin, fibronectin, and C1-esterase-inhibitor (C1-Inh) genes were examined by Northern-blot hybridizations. Determinations of serum-glucose and glycogen staining by periodic acid and Schiff were performed to analyze changes in glucose mobilization and storage.

RESULTS

In regenerating liver tissue after PH and PBL, we detected a selective reduction of transcripts encoding G6P during the prereplicative period 6 and 12 h after surgery and a contemporary drop in serum glucose levels. This impairment proved to be more distinct after PH than after PBL. Compared with the residual liver after PH, the level of glycogen disappearance was lower after PBL in the regenerating lobe. In the portal-deprived liver tissue, the expression of genes coding for G6P, GR, GAPDH, albumin, fibronectin, and C1-Inh was not altered compared with the SO group.

CONCLUSIONS

Overall, portal-deprived liver tissue undergoing atrophy retains its liver-specific differentiation and function and helps to maintain homeostasis during the fast regeneration of the non-occluded liver lobe.

Evaluation of the effect of portal vein embolization on liver function by (99m)tc-galactosyl human serum albumin scintigraphy

BACKGROUND

Preoperative percutaneous transhepatic portal vein embolization (PTPE) increases the safety of liver resection and improves the outcome after surgery for hepatocellular carcinoma. Scintigraphy with (99m)Tc-galactosyl human serum albumin (GSA) causes specific binding to viable hepatocytes and serves as an index of liver function.

MATERIALS AND METHODS

(99m)Tc-GSA scintigraphy was performed before and 2 weeks after PTPE of the right portal vein in 16 patients. The total receptor index, reflecting overall liver function, right receptor index (right lobe), and left receptor index (left lobe) were calculated.

RESULTS

After PTPE, the proportion of the volume of the nonembolized lobe (left lobe) increased (P = 0.0002). The total receptor index slightly decreased after PTPE (P = 0.090), the right receptor index decreased (P < 0.0001), and the left receptor index increased (P < 0.0001). The average increase rate in the left receptor index was 30% of the pre-PTPE value. In 2 patients with portal hypertension (> or =30 cm H(2)O) after PTPE, the left receptor index did not change. In 4 patients whose left receptor index after PTPE (including the 2 patients with portal hypertension) was <0.35, right lobectomy was not performed.

CONCLUSIONS

(99m)Tc-GSA scintigraphy demonstrated that PTPE induces a shift in hepatic function from the embolized part to the nonembolized part of the liver. PTPE of the right portal vein increases the hepatic functional reserve of the left lobe as well as its volume. The changes in (99m)Tc-GSA uptake following PTPE may predict the response to liver resection.

Improved functional reserve of hypertrophied contra lateral liver after portal vein ligation in rats

BACKGROUND/AIMS

We assessed the functional capacity of hypertrophied liver after portal vein ligation (PL) in a test group of rats compared to a control group (without PL) having the same size liver.

METHODS

The portal veins of the left and median lobes in the test group were ligated in an initial operation. Four days after the PL, the liver volume of the posterior caudate lobe (5%) increased two-fold, accounting for 10% of the liver. Then a 90% hepatectomy was performed, leaving only the hypertrophied posterior caudate lobe. Rats in a sham group underwent a 90% hepatectomy 4 days after having laparotomy, leaving the normal anterior and posterior caudate lobes (10%).

RESULTS

The survival rate for the PL group was significantly higher than for the sham group at 4 days after hepatectomy (56.3 and 26.7%, P<0.05). The regeneration ratio and the proliferating cell nuclear antigen (PCNA) labeling index in the PL group was markedly higher than in the sham group 24h after hepatectomy.

CONCLUSIONS

Hypertrophied liver at 4 days after PL still showed liver regeneration. Regenerating liver provided greater tolerance for extended hepatectomy than normal liver. This is because of the induced rapid regeneration of the remaining liver after hepatectomy.

Selective versus total drainage for biliary obstruction in the hepatic hilus: an experimental study

BACKGROUND

Controversy exists as to whether selective biliary drainage (SBD) or total biliary drainage (TBD) is preferable as a preoperative procedure before extended hemihepatectomy for hilar cholangiocarcinoma, especially with regard to the functional reserve of the future remnant liver.

METHODS

SBD or TBD was performed after 1 week of total biliary obstruction in rats. In SBD, the biliary trees of the left lobes (approximately 70% of the liver) were kept obstructed, whereas the right lobes were drained selectively. Mitochondrial function and microsomal cytochrome content were examined before and 1, 2, and 4 weeks after drainage.

RESULTS

The right lobes weighed significantly more after SBD than after TBD. There were no significant differences in mitochondrial function between the two groups. The microsomal cytochrome content per milligram of microsomal protein significantly decreased 1 week after biliary obstruction and then recovered to a similar extent after SBD and TBD in the right lobes. However, the total microsomal cytochrome content (nanomoles per 100 g body weight) and the overall rate of mitochondrial adenosine triphosphate synthesis (mmoles per minute per 100 g of body weight) in the right lobes 4 weeks after SBD were significantly greater than those after TBD.

CONCLUSIONS

SBD is superior to TBD with regard to the functional reserve of the future remnant liver.

Erythrocytosis caused by an erythropoietin-producing hepatocellular carcinoma

A case of erythrocytosis caused by a hepatocellular carcinoma (HCC) that produced erythropoietin (Epo) is described. A 64-year-old man, with a huge HCC tumor in the right lobe of the liver, showed a high concentration of hemoglobin and increased levels of serum Epo, alpha-fetoprotein (AFP), and protein induced by vitamin K absence II (PIVKA-II). Right lobectomy of the liver was performed. Histological findings of the specimen showed a moderately differentiated HCC. The existence of Epo was confirmed immunohistochemically only in the tumor tissue and not in the normal liver tissue. Erythrocytosis disappeared and the serum levels of Epo, AFP, and PIVKA-II returned to the normal range after the operation. Within 2 months after the operation, recurrent tumors appeared in the remnant liver, and the patient died 13 months after the operation.

Preventive effect of preoperative portal vein ligation on endotoxin-induced hepatic failure in hepatectomized rats is associated with reduced tumour necrosis factor alpha production

BACKGROUND

Preoperative portal vein embolization successfully reduces the incidence of postoperative hepatic failure in which endotoxin is postulated to be involved. To identify the mechanism of this preventive effect, the relationship of endotoxin-induced liver injury with tumour necrosis factor (TNF) alpha and nitric oxide production in the peripheral blood, liver and spleen of rats subjected to preoperative portal vein branch ligation (PVL) was compared with that in rats undergoing sham operation.

METHODS

Rats with PVL and those that underwent sham operation were subjected to resection of ligated liver lobes (PVL-Hx rats) and two-thirds hepatectomy (noPVL-Hx rats) respectively at day 5, followed by intravenous administration of endotoxin 200 microgram/kg body-weight at day 7. At various time intervals after endotoxin injection, the peripheral blood, liver and spleen tissues were harvested and analysed for TNF-alpha and nitric oxide production.

RESULTS

The survival rates of noPVL-Hx and PVL-Hx rats at 48 h after endotoxin administration were 40 and 100 per cent respectively. The former rats showed more extensive liver injury as represented by higher serum aminotransferase and hyaluronate levels than the latter. Plasma concentrations of TNF-alpha at 1.5 h after endotoxin treatment were significantly higher in noPVL-Hx rats (mean(s.e.m.) 22 125(2175) pg/ml; n = 6) than PVL-Hx rats (8344(4076) pg/ml; n = 6) (P < 0.01). Consistent with this, expression of TNF-alpha messenger RNA in the liver and spleen was suppressed in PVL-Hx rats. In two-thirds hepatectomized rats, plasma TNF-alpha concentrations after endotoxin administration at 1, 2 and 3 days (14 350(2186), 26 375(2478) and 23 000(3745) pg/ml respectively; n = 6 each) were significantly higher than that before operation (9067(1559) pg/ml; n = 6) (P < 0.05), whereas those at 5 and 7 days (10 102(3616) and 8580(1427) pg/ml respectively; n = 6 each) showed no significant increase. Furthermore, nitric oxide production in peripheral blood and liver was suppressed by preoperative PVL.

CONCLUSION

Prevention of endotoxin-induced liver failure by preoperative PVL is associated with reduced production of TNF-alpha in the later phase of liver regeneration.

Preoperative portal vein embolization improves prognosis after right hepatectomy for hepatocellular carcinoma in patients with impaired hepatic function

BACKGROUND

Percutaneous transhepatic portal vein embolization (PTPE) increases the safety of subsequent major hepatectomy. The aim of this study was to determine the effect of PTPE on long-term prognosis after hepatectomy in patients with hepatocellular carcinoma (HCC).

METHODS

Seventy-one patients with HCC underwent right hepatectomy between 1984 and 1998. Preoperative PTPE was performed in 33 patients (group 1) and was not used in 38 patients (group 2). Outcome after operation was compared between the groups. The patients were further divided according to the median tumour diameter (cut-off 6 cm) and indocyanine green retention rate at 15 min (ICGR15) (cut-off 13 per cent).

RESULTS

The cumulative survival rate was significantly higher in group 1 than in group 2 in patients with an ICGR15 of at least 13 per cent. Tumour-free survival rates were similar in both groups. Of patients with tumour recurrence after right hepatectomy, those in group 1 were more frequently subjected to further treatment.

CONCLUSION

Preoperative PTPE improves the prognosis after right hepatectomy for HCC in patients with impaired hepatic function, although it does not prevent tumour recurrence.

Course before and after percutaneous transhepatic portal vein embolization of a patient with cholangiocarcinoma monitored by scintigraphy with Tc-99m galactosyl human serum albumin

Percutaneous transhepatic portal vein embolization (PTPE) causes atrophy of the embolized lobe and compensatory hypertrophy of the nonembolized lobe, and improves the safety of hepatectomy. We report a patient with cholangiocarcinoma who underwent embolization of both anterior and posterior branches of the right portal vein before hepatectomy. Scintigraphy with Tc-99m galactosyl human serum albumin was performed before and 4 weeks after PTPE. After PTPE, the right lobe of the liver was atrophied and the left lobe of the liver was enlarged, compared with before PTPE. The receptor index of the entire liver was almost unchanged before and after PTPE, but the right lobe receptor index after PTPE was 23% less than the pre-PTPE value, whereas the left lobe receptor index had increased 37%. Scintigraphy with Tc-99m galactosyl human serum albumin is useful for evaluating segmental functional reserve before and after PTPE.

Differential regenerative response and expression of growth factors following hepatectomy of variable extent in rats

AIMS/BACKGROUND

Liver regeneration is a physiological mechanism which leads to restoration of the hepatic parenchyma following hepatectomy or toxic injury. This process is mediated by a wide variety of cytokines and growth factors. The aim of the present study was to evaluate the influence of hepatectomy extent on the levels of intrahepatic mRNAs for cell-cycle markers and growth factors in rats submitted to a 30%, two-third or 80% hepatectomy.

METHODS

Cyclins, thymidine kinase and growth factors mRNA levels were quantitatively assessed by RT-PCR at different time points post-hepatectomy (2h, 6h, 12h, days 1, 2, 6).

RESULTS

As compared with a two-third hepatectomy, cyclins and thymidine kinase mRNA levels were increased but with a delayed peak at day 2 in the 80% hepatectomy group and showed a progressive increase until day 6 in the 30% hepatectomy group; mRNA levels for HGF or TGFalpha were increased with a delayed peak at 12 h or day 2 in the 80% hepatectomy group, respectively and this delay was more pronounced in the 30% hepatectomy group with a peak at day 1 or day 6.

CONCLUSION

A regenerative response occurs whatever the extent of hepatectomy but the course of regeneration and expression of growth factors differs according to the volume of resected liver. A better knowledge of these events could improve the clinical results of hepatic resection for primary or metastatic liver disease.

Effect of preoperative portal vein embolization on major hepatectomy for advanced-stage hepatocellular carcinomas in injured livers: a preliminary report

With the aim of minimizing postoperative liver dysfunction and promoting increased resectability, we employed portal vein embolization (PVE). In this study, the effect of PVE on major hepatic resection for advanced-stage hepatocellular carcinoma (HCC) in injured livers was evaluated. PVE was performed prior to hepatectomy in 13 patients with stage III and IV HCCs. Following PVE, right trisegmentectomy was performed in 3 patients, extended right lobectomy in 3 and right lobectomy in 7. To evaluate the effect of PVE, the changes in liver functional capacity and estimated remnant liver volume (ERLV), determined by computed tomography, were examined before and after PVE. The operative morbility, mortality, and survival rates after hepatectomy were also assessed. By 2 weeks after PVE, ERLV had increased in all patients, by an average of 28%, and the mean resection rates had decreased from 70.0% to 62.2%. Postoperatively, the 30-day mortality rate was 15.3%, and the 1- and 2-year survival rates were 69% and 46%, respectively. The results of this study indicate that resectability can be increased, and major hepatectomy can be made safer by employing PVE preoperatively, in view of the fact that major hepatectomy was not considered feasible without PVE in these patients.