Impact of neoadjuvant cetuximab on liver function and tumor reduction in a murine model of selective portal vein ligation

Two strategies are clinically available to induce selective hypertrophy of the liver: portal vein embolization (PVE) and portal vein ligation (PVL). The aim of this study was to compare the impact of PVE and PVL on liver regeneration. Rats were subjected to 70% PVL, 70% PVE, 70% partial hepatectomy (PH) (positive control), or sham operation (negative control). PVL and PVE of liver segments were validated by portography and histology, demonstrating obstruction of the involved portal branches. Liver weight and markers of regeneration were assessed at 24, 48, and 72 hours, and 7 days after surgery (n = 5). Sinusoidal perfusion was examined by intravital microscopy. The weight of the regenerating liver segments increased continuously in all groups, with the highest weight gain after PH, which also disclosed the strongest proliferative activity. In Ki-67 and PCNA stainings, hepatocyte proliferation after PVL was more pronounced than after PVE (P = 0.01). Volumetric blood flow and functional sinusoidal density were lower after PVE than after PVL (P = 0.006, P = 0.02, respectively). The accumulation of Kupffer cells 24 hours after the intervention was highest after PH. Transcript levels of cytokines (interleukin-1beta, tumor necrosis factor-alpha, interleukin-6) peaked at 24 hours and were highest after PH. The embolized part of the liver after PVE showed prominent foreign body reaction in the portal triad with accumulation of macrophages. PVL is superior to PVE in inducing a regenerative response of the remnant liver. The impairment of liver regeneration after PVE may be a consequence of macrophage trapping in the occluded segment due to a foreign body reaction. Lower blood flow and lower accumulation of macrophages, particularly Kupffer cells, in the regenerating part of the liver likewise causes impaired liver regeneration after PVE.

Simple SummaryFewer than 30% of patients with liver metastases are eligible for major liver resection, because liver remaining after such a surgery would be insufficient to cover the patient’s needs; this is called a low percentage of future liver remnant (FLR). Folinic acid (FA) has been shown to play a crucial role in cellular synthesis, regeneration, and nucleotide and amino acid biosynthesis. The aim of this piece of research was to evaluate the effect of FA as a potential hypertrophic hepatic enhancer agent after selective portal vein ligation (PVL) to ensure adequate FLR. We have confirmed in our rodent model that FA accelerates liver regeneration after PVL and enhances recovery of liver function. These findings may allow more patients to be eligible for liver resection without jeopardizing postoperative liver function.Liver resection remains the gold standard for hepatic metastases. The future liver remnant (FLR) and its functional status are two key points to consider before performing major liver resections, since patients with less than 25% FLR or a Child–Pugh B or C grade are not eligible for this procedure. Folinic acid (FA) is an essential agent in cell replication processes. Herein, we analyze the effect of FA as an enhancer of liver regeneration after selective portal vein ligation (PVL). Sixty-four male WAG/RijHsd rats were randomly distributed into eight groups: a control group and seven subjected to 50% PVL, by ligation of left portal branch. The treated animals received FA (2.5 m/kg), while the rest were given saline. After 36 h, 3 days or 7 days, liver tissue and blood samples were obtained. FA slightly but significantly increased FLR percentage (FLR%) on the 7th day (91.88 ± 0.61%) compared to control or saline-treated groups (86.72 ± 2.5 vs. 87 ± 3.33%; p < 0.01). The hepatocyte nuclear area was also increased both at 36 h and 7days with FA (61.55 ± 16.09 µm2, and 49.91 ± 15.38 µm2; p < 0.001). Finally, FA also improved liver function. In conclusion, FA has boosted liver regeneration assessed by FLR%, nuclear area size and restoration of liver function after PVL.

Associated liver partition and portal vein ligation for staged hepatectomy (ALPPS) is a two-stage hepatectomy technique which can be associated with a hypertrophic stimulus on the future liver remnant (FLR) stronger than other techniques–such as portal vein ligation (PVL). However, the reason of such hypertrophy is still unclear, but it is suggested that liver transection combined with portal vein ligation (ALPPS) during the first stage of this technique may play a key role. The aim of this study is to compare the hypertrophic stimulus on the FLR and the clinical changes associated with both ALPPS and PVL in a rat surgical model. For this purpose, three groups of SD rats were used, namely ALPPS (n = 30), PVL (n = 30) and sham-treated (n = 30). The second stage of ALPPS (hepatectomy of the atrophic lobes), was performed at day 8. Blood and FLR samples were collected at 1, 24, 48 hours, 8 days and 12 weeks after the surgeries. ALPPS provoked a greater degree of hypertrophy of the FLR than the PVL at 48 hours and 8 days (p<0.05). The molecular pattern was also different, with the highest expression of IL-1β at 24h, IL-6 at 8 days, and HGF and TNF-α at 48 hours and 8 days (p<0.05). ALPPS also brought about a mild proliferative stimulus at 12 weeks, with a higher expression of HGF and TGF-β (p<0.05) than PVL. Clinically, ALPPS caused a significant liver damage during the first 48 hours, with a recovery of liver function at day 8. In conclusion, ALPPS seems to induce higher functional hypertrophy on the FLR than PVL at day 8. Such regenerative response seems to be leaded by a complex interaction between pro-mitogenic (IL-6, HGF, TNF-α) and antiproliferative (IL1-β and TGF-β) cytokines.

Introduction Colorectal cancer liver metastases (CRCLM) continue to be a therapeutic challenge, since their resectability is usually limited by the functionality of the liver remnant. In this context, it is necessary to study the regenerative response of the liver in a selective portal vein ligation (PVL) model, after the administration of 5-fluorouracil and oxaliplatin, and to assess the effect of compensatory hypertrophy on tumor progression. Methods Twenty-eight WAG/RijHsd rats carrying CRCLM were divided into four groups: control, PVL, 5FU (50mg/kg) and 5FU+Oxaliplatin (50mg/kg+10mg/kg). After 18 days of tumor development, a dose of the corresponding treatment was administered, performing a PVL of 50% 72h later. Seven days later, tumor size was quantified and a biochemical profile was performed. Results The 5FU+Oxaliplatin and 5FU alone treatment decreased tumor growth by 6 and 3 times compared to the PVL and control groups, respectively (p&amp;lt;0.001). At a biochemical level, the combination of drugs resulted in a decrease in albumin levels (3.3 ± 0.39 mg/dl; p&amp;lt;0.02) and a significant weight loss of 10%; however, glucose (152±6.6 mg/dl), AST (161±27.1 IU/L), and ALT (46.7±9.4 IU/L) were not significantly altered. Seven days after PVL, the liver remnant did not change in either group (5FU+Oxaliplatin: 8±1; 5FU: 9.7±1.2; control 9.4±1.9 g; p&amp;gt;0.05). Conclusion In our model, the combined therapy of 5-Fluorouracil and oxaliplatin, prior to PVL, does not affect the necessary hepatic regeneration; while the volume of tumor implants decreases, no significant alteration of the biochemical parameters is detected.

Background and aimsPatients with bilobular colorectal liver metastases (CRLM) experience poor prognosis, especially when curative resection cannot be achieved. However, resectability in these patients is often limited by low future remnant liver volume (FRLV). The latter can be enhanced by a two-stage liver resection, using portal vein ligation to induce liver hypertrophy. The aim of this prospective pilot study was to evaluate safety, secondary resectability, and time to recurrence of two-stage hepatectomy with portal vein ligation (PVL) and complete surgical clearance of the FRLV in patients with bilobular CRLM.Materials and methodsOut of 24 patients (63 ± 8.26 years) with extended bilobular CRLM (metachronous n = 10, synchronous n = 14), 18 received preoperative 5-FU-based chemotherapy combined with oxaliplatin or irinotecan. Staging included thoracoabdominal computed tomography and 18F-fluorodeoxyglucose-positron emission tomography scans. First-stage procedure consisted of PVL, resection of all CRLM in the FRLV, and radiofrequency ablation (RFA) of CRLM situated near the future resection plane.ResultsDuring first-stage procedure, 7× RFA, 4× non-anatomical resections, and 4× bisegmentectomies were performed additionally to PVL. FRLV/body-weight ratio increased from 0.4% to 0.6% within 55 days (median) after PVL. Second-stage hepatectomy was performed in 19 patients without tumor progression. R0 resection was possible in 14 patients. During a median follow-up of 17 months, intrahepatic recurrence occurred in two, and extrahepatic recurrence in nine out of 14 patients.ConclusionTwo-stage hepatectomy with PVL and complete surgical clearance of FRLV is safe even after intensified systemic chemotherapy resulting in a curative resection rate of 58.3% (73.7% of re-explored cases).

The alcohol injection into portal vein prior to ligation increases hepatic regeneration rate

Selective portal vein ligation and embolization induce different tumoral responses in the rat liver

BackgroundThe underlying mechanism of liver regeneration after Associating Liver Partition and Portal vein ligation (PVL) for Staged hepatectomy (ALPPS) is still unclear. The aim of this study was to evaluate the relationship between future liver remnant (FLR) volume, liver regeneration characteristics and restoration of function in an experimental model of ALPPS.MethodsAn ALPPS model in rats was developed with selective PVL, parenchymal transection and partial hepatectomy (step 1), followed by resection of the liver (step 2). Three different ALPPS groups with FLR sizes of 30, 20 and 10 per cent of total liver volume were compared with sham‐operated controls and animals undergoing resection of left lateral lobe and 90 per cent PVL with respect to morbidity, mortality, liver regeneration and function.ResultsThree of 15 animals that had ALPPS with 10 per cent FLR (ALPPS10) died after step 1. Ascites developed in two of five rats that had ALPPS with 20 per cent FLR and in three of four animals in the ALPPS10 group after step 2. Although the relative increments in FLR size and growth rates were highest in the ALPPS groups, small FLR size was associated with a sustained increase in levels of serum aminotransferases and bilirubin, a lower albumin concentration, severe sinusoidal injury, increased expression of proliferation markers and increased activation of hepatic progenitor cells after step 2.ConclusionThere is discordance between FLR volume increase and functional restoration after the ALPPS procedure.

Portal vein ligation (PVL) has been used clinically to decrease the amount of liver before surgical resection, consequently, minimizing postoperative dysfunction in the remaining hypertrophied liver lobes. To date, few reports in the literature have demonstrated the regenerative capacity of unaffected lobes following PVL plus hepatic artery ligation (HAL). This study was conducted in rats to determine a safe and efficacious method of PVL plus HAL, focusing on liver function, the MIB-5 labeling index, and the ratio of the weight of the nonligated lobes to the body weight. Group I rats were subjected to PVL of the left lateral and median branches alone (corresponding to approximately 70% total liver volume). In group II, we performed PVL and HAL of the same branches simultaneously, while in group III, HAL was performed 48 h after PVL. A laparotomy without ligature was performed in the control group. Rats from each group were killed at 24, 48, 72, 96, and 168 h after surgery. Standard serum liver functions were tested. Proliferative activity in the nonligated liver was expressed using the Ki-67 antigen (MIB-5) labeling index. Body and nonligated lobe weights were measured. At 96 h post-surgery, the ratio of the weight of the nonligated lobe to body weight was significantly higher in group III than in group I and group II, and induction of the MIB-5 labeling index showed maximum levels in group III. However, quantitative determination of serum glutamic-oxaloacetate transaminase (GOT) showed peak levels in group II at 24 h after surgery. From these results, we conclude that the PVL plus HAL heterochronous procedure is safer and more efficacious than PVL only, or simultaneous PVL plus HAL. A better knowledge of the events following such heterochronous ligation should improve the clinical outcome of hepatic resection for liver diseases.

Surgical resection of colorectal liver metastases is agold standard treatment. The indication criteria still continue expanding. The future liver remnant volume (FLRV) remains the only limiting factor of the resection. Many methods have been discussed to increase the FLRV. Injection of absolute alcohol into the portal vein seems to be one of the most effective. In 2018 we perioperatively injected 25 ml of absolute alcohol into the ligated right portal branch in 3 patients with colorectal liver metastases at our department. All patients were indicated for second-stage right hemihepatectomy. The mean FLRV increase was 206.6 cm3 46 weeks after absolute alcohol injection. Atransient elevation of transaminases was observed with spontaneous regression within 10 days from alcohol injection. There was no complication clearly associated with alcohol application. No liver failure was observed. No patient died. All three patients underwent second-stage right hemihepatectomy. Portal vein ligation with alcohol injection can be an uncomplicated and highly effective method to achieve FLRV hypertrophy.

Selective portal vein ligation (PVL) allows the two-stage surgical resection of primarily unresectable liver tumours by generating the atrophy and hypertrophy of portally ligated (LL) and non-ligated lobes (NLL), respectively. To evaluate critically important underlying functional alterations, present study characterised in vitro and vivo liver function in male Wistar rats (n = 106; 210–250 g) before, and 24/48/72/168/336 h after PVL. Lobe weights and volumes by magnetic resonance imaging confirmed the atrophy-hypertrophy complex. Proper expression and localization of key liver transporters (Ntcp, Bsep) and tight junction protein ZO-1 in isolated hepatocytes demonstrated constantly present viable and well-polarised cells in both lobes. In vitro taurocholate and bilirubin transport, as well as in vivo immunohistochemical Ntcp and Mrp2 expressions were bilaterally temporarily diminished, whereas LL and NLL structural acinar changes were divergent. In vivo bile and bilirubin-glucuronide excretion mirrored macroscopic changes, whereas serum bilirubin levels remained unaffected. In vivo functional imaging (indocyanine-green clearance test; 99mTc-mebrofenin hepatobiliary scintigraphy; confocal laser endomicroscopy) indicated transitionally reduced global liver uptake and -excretion. While LL functional involution was permanent, NLL uptake and excretory functions recovered excessively. Following PVL, functioning cells remain even in LL. Despite extensive bilateral morpho-functional changes, NLL functional increment restores temporary declined transport functions, emphasising liver functional assessment.

Background: Surgical removal of complicated liver tumors may be realized in two stages via selective portal vein ligation, inducing the atrophy of portally ligated lobes and the compensatory hypertrophy of nonligated liver lobes. Unlike morphological changes, functional aspects such as hepatic cytochrome P450 (CYP)-mediated drug metabolism remain vaguely understood, despite its critical role in both drug biotransformation and hepatic functional analysis. Our goal was the multilevel characterization of hepatic CYP-mediated drug metabolism after portal vein ligation in the rat. Methods: Male Wistar rats (n = 24, 210–230 g) were analyzed either untreated (controls; n = 4) or 24/48/72/168/336 h (n = 4 each) following portal vein ligation affecting approximately 80% of the liver parenchyma. Besides the weights of ligated and nonligated lobes, pentobarbital (30 mg/kg)-induced sleeping time, CYP1A(2), CYP 2B(1/2), CYP2C(6/11/13), CYP3A(1) enzyme activities, and corresponding isoform mRNA expressions, as well as CYP3A1 protein expression were determined by in vivo sleeping test, CYP isoform-selective assays, polymerase chain reaction, and immunohistochemistry, respectively. Results: Portal vein ligation triggered atrophy in ligated lobes and hypertrophy nonligated lobes. Sleeping time was transiently elevated (p = 0.0451). After an initial rise, CYP1A, CYP2B, and CYP3A enzyme activities dropped until 72 h, followed by a potent increase only in the nonligated lobes, paralleled by an early (24–48 h) transcriptional activation only in nonligated lobes. CYP2C enzyme activities and mRNA levels were bilaterally rapidly decreased, showing a late reconvergence only in nonligated lobes. CYP3A1 immunohistochemistry indicated substantial differences in positivity in the early period. Conclusions: Beyond the atrophy-hypertrophy complex, portal vein ligation generated a transient suppression of global and regional drug metabolism, re-established by an adaptive, CYP isoform-dependent transcriptional response of the nonligated lobes.

Selective portal vein occlusion prior to aggressive hepatic resection is now an alternative way to decrease postoperative morbidity and mortality rates. However, the detailed changes in the hepatic energy status and DNA synthesis rate in both portal vein ligated (PVL) and nonligated (PVNL) lobes of the liver are not clear. In rats, the portal branch that supplies 70% of the liver volume was ligated, and changes in arterial ketone body ratio (AKBR), liver weight, histology, DNA synthesis rate and adenine nucleotides of the PVL and PVNL liver lobes were determined before and 1, 2, 4 and 7 days after portal vein ligation, and compared with those in sham-operated rats. The weight of the PVL lobes decreased, while that of the PVNL lobes increased depending on time. The DNA synthesis rates of the PVNL lobes were significantly higher than those in sham-operated control liver during the first 4 days with the maximal value on the 2nd day, while those of PVL lobes were essentially similar to the control values. Energy charge (EC) in both PVL and PVNL lobes significantly decreased on day 1 and recovered gradually, but with less extent in the regenerating PVNL lobes. The concentrations of total adenine nucleotides (TAN) in both the PVL and PVNL lobes were essentially similar during the first 2 days, but became significantly lower in PVL lobes after day 4. A decrease in EC preceded an increase in DNA synthesis only in the PVNL lobes, in contrast to the PVL lobes. Mitosis of hepatocytes on day 2 and subsequently enlarged lobules with an increased number of hepatocytes were histologic features in the PVNL liver. The AKBR was not correlated with hepatic energy charge of the liver. In conclusion, PVNL liver regenerates preceded by a decrease in EC and a subsequent increase in DNA synthesis keeping TAN constant, while PVL liver becomes atrophic, with a similar change in EC of the PVNL liver but ultimately decreased TAN without any change in DNA synthesis. AKBR is not a parameter reflecting the hepatic EC after portal branch ligation.

Les métastases hépatiques bilobaires des cancers colorectaux posent un problème de prise en charge, la chirurgie curative nécessite souvent plusieurs temps. Le but de notre étude était d´évaluer l´approche laparoscopique avec ligature portale dans le premier temps des hépatectomies en deux temps pour les métastases hépatiques synchrones des cancers colorectaux (MHSCCR). Il s´agissait d´une étude rétrospective monocentrique d´août 2016 à janvier 2020 qui avait inclus les patients présentant des MHSCCR nécessitant une chirurgie curative en deux temps à cause d´une insuffisance du volume du futur foie restant (FFR). L´objectif principal était d´évaluer la morbi-mortalité postopératoire du premier temps laparoscopique à 30 jours. Les objectifs secondaires étaient d´évaluer le taux de conversion, l´hypertrophie du FFR après ligature portale laparoscopique, la morbi-mortalité postopératoire du 2e temps hépatique et enfin d´évaluer le taux d´achèvement de la stratégie thérapeutique. Nous avons inclus six patients (4 hommes et 2 femmes), l´âge moyen était de 64 (44-72) ans, le premier temps opératoire avait consisté en une résection colique laparoscopique associée à une ligature portale droite chez 5 patients et gauche chez un patient. La morbi-mortalité postopératoire était nulle. Le taux de conversion était nul. Après ligature portale, 5 sur les 6 patients avaient hypertrophié le FFR de façon significative, le gain moyen de volume du FFR était de 59,48% (31,02%-68,71%). Deux patients parmi les six avaient présenté une morbidité sévère après le deuxième temps hépatique (Clavien IIIb). La stratégie thérapeutique a été achevée chez tous les malades.

Colorectal carcinoma (CRC) is the third leading cause of cancer-related death in the United States. The liver is the most frequent site of metastasis and a key determinant of survival in patients with isolated colorectal liver metastasis (CRLM). Surgical resection remains the only hope for prolonged survival in patients with CRLM. However, most patients are deemed to be unresectable at presentation due to a small future liver remnant (FLR) and fear of post-hepatectomy liver failure. Procedures such as portal vein ligation or embolization (PVL/PVE) followed by hepatectomy have been established as standard methods to increase FLR volume, but have limitations dependent upon extent of disease and patient's ability to grow the liver remnant. Recently, associating liver partition and portal vein ligation in staged hepatectomy (ALPPS) has been introduced as a technique to induce liver hypertrophy over a shorter time period. Being a complex two-stage surgical procedure, initial reports of higher ALPPS-associated complications and mortality limited its worldwide adoption by hepatobiliary surgeons. However, recent studies have showed ALPPS superiority over conventional procedures in terms of feasibility and inducing liver hypertrophy, with comparable morbidity and mortality. We herein review the role of ALPPS in management of patients with CRLM.