Liver regeneration after major hepatectomy for biliary cancer

Early Surgical Outcome of Hepatoblastoma in Children Receiving Chemotherapy After Hepatic Resection

OBJECTIVE

 The aim of this study was to evaluate surgical outcomes in children with hepatoblastoma who underwent hepatic resection after receiving neoadjuvant chemotherapy.

METHODOLOGY

A prospective observational longitudinal study was conducted from February 2019 to July 2020 in the Department of Pediatric Surgery at Bangabandhu Sheikh Mujib Medical University, Bangladesh. A total of 13 children diagnosed with hepatoblastoma and classified as PRETEXT (Pre-Treatment Extent of Disease) stages I to III were included. Detailed medical histories were recorded, and diagnoses were confirmed through histopathological analysis. Preoperative evaluations included liver function tests (LFTs), serum alpha-fetoprotein (AFP) levels, and imaging for tumor staging and liver volume. Postoperative assessments were conducted at one, three, and six months to monitor changes in serum AFP levels, LFTs, liver volume, and hepatic echotexture. The type of hepatic resection performed and any complications encountered were also documented.

RESULTS

Among the 13 patients, the majority were male, with a male-to-female ratio of 12:1. The average age at diagnosis was 4.44 years, with most patients under three years old. Pathological analysis revealed epithelial tumors in 38.45% of cases, fetal-type tumors in 46.15%, and mixed tumors in 15.4%. PRETEXT stage III was the most common (53.85%), and 61.54% of patients underwent major hepatic resections. Postoperative serum AFP levels showed a significant decline, reflecting successful tumor resection and improvements in LFTs. Improvements in LFTs, including key enzymes like ALT and AST, were observed. A marked increase in hepatic regeneration was observed within six months, with no local recurrences recorded.

CONCLUSIONS

This study highlights the effectiveness of combining hepatic resection with neoadjuvant chemotherapy in treating pediatric hepatoblastoma. A significant decline in serum AFP levels after surgery reflects the success of tumor removal, while improvements in LFTs underscore the recovery of hepatic health. Furthermore, the observed increase in hepatic regeneration within six months demonstrates the liver's remarkable ability to recover and sustain long-term function. These findings emphasize the importance of early diagnosis, precise surgical techniques, and individualized treatment planning in improving outcomes for pediatric hepatoblastoma.

The role of surgical approach in recovery from extrahepatic cholangiocarcinoma: hemihepatectomy vs. pancreatoduodenectomy

BACKGROUND

This study compared short- and mid-term outcomes of hemihepatectomy (HH) and pancreatoduodenectomy (PD) in patients with extrahepatic cholangiocarcinoma, focusing on surgical outcomes, body composition, and nutritional status.

METHOD

A retrospective review was conducted to assess short-term outcomes, including operative time, blood loss, complications, and mortality. Body composition and nutritional parameters were analyzed preoperatively and 1 year postoperatively. Multivariate analysis identified factors influencing outcomes.

RESULT

Among 216 patients (HH: n = 94, PD: n = 122), HH was associated with younger age (median 72 vs. 74 years, p = 0.041), longer operative times (p = 0.008), and greater blood loss (p < 0.001) compared to PD. Despite this, HH had fewer severe complications (42.6% vs. 75.4%, p < 0.001), lower rates of pancreatic fistula (5.3% vs. 60.7%, p < 0.001), and shorter postoperative hospital stays (p = 0.002). Mortality occurred in 3 HH patients (3.2%), all of whom underwent right hemihepatectomy, compared to none in PD (p = 0.081). One year postoperatively, HH patients had better preservation of skeletal muscle area (p = 0.139), body fat area (p = 0.319), and hemoglobin levels (p = 0.060) compared to significant declines observed in PD patients (all p < 0.001). Multivariate analysis indicated that HH was independently associated with better preservation of skeletal muscle area (β = 2.58, p < 0.001), body fat area (β = 20.86, p < 0.001), and hemoglobin levels (β = 0.81, p = 0.009) at one year postoperatively.

CONCLUSION

HH was associated with better preservation of physical and nutritional status compared to PD. However, the higher perioperative mortality observed in HH, particularly right hemihepatectomy, necessitates careful consideration of the risks and benefits when selecting the surgical approach for patients with extrahepatic cholangiocarcinoma.

Evaluation of liver regeneration after hemi-hepatectomy by combining computed tomography and post-operative liver function

Background

Accurate evaluation of postoperative liver regeneration is essential to prevent postoperative liver failure.

Aims

To analyze the predictors that affect liver regeneration after hemi-hepatectomy.

Method

Patients who underwent hemi-hepatectomy in Hangzhou First People's Hospital and Hangzhou Shulan Hospital from January 2016 to December 2021 were enrolled in this study. The regeneration index (RI) was calculated by the following equation: RI = [(postoperative total liver volume {TLVpost} - future liver remnant volume {FLRV}/FLRV] × 100 %. Hepatic dysfunction was defined according to the "TBilpeak>7" standard, which was interpreted as (peak) total bilirubin (TBil) >7.0 mg/dL. Good liver regeneration was defined solely when the RI surpassed the median with hepatic dysfunction. Logistic regression analyses were performed to estimate prognostic factors affecting liver regeneration.

Result

A total of 153 patients were enrolled, with 33 in the benign group and 120 patients in the malignant group. In the entire study population, FLRV% [OR 4.087 (1.405-11.889), P = 0.010], international normalized ratio (INR) [OR 2.763 (95%CI, 1.008-7.577), P = 0.048] and TBil [OR 2.592 (95%CI, 1.177-5.710), P = 0.018] were independent prognostic factors associated with liver regeneration. In the benign group, only the computed tomography (CT) parameter FLRV% [OR, 11.700 (95%CI, 1.265-108.200), P = 0.030] predicted regeneration. In the malignant group, parenchymal hepatic resection rate (PHRR%) [OR 0.141 (95%CI, 0.040-0.499), P = 0.002] and TBil [OR 3.384 (95%CI, 1.377-8.319), P = 0.008] were independent prognostic factors.

Conclusion

FLRV%, PHRR%, TBil and INR were predictive factors associated with liver regeneration.

Surgical management of hilar cholangiocarcinoma: Controversies and recommendations

Hilar cholangiocarcinomas are highly aggressive malignancies. They are usually at an advanced stage at initial presentation. Surgical resection with negative margins is the standard of management. It provides the only chance of cure. Liver transplantation has increased the number of 'curative' procedures for cases previously considered to be unresectable. Meticulous and thorough preoperative planning is required to prevent fatal post-operative complications. Extended resection procedures, including hepatic trisectionectomy for Bismuth type IV tumors, hepatopancreaticoduodenectomy for tumors with extensive longitudinal spread, and combined vascular resection with reconstruction for tumors involving hepatic vascular structures, are challenging procedures with surgical indications expanded. Liver transplantation after the standardization of a neoadjuvant protocol described by the Mayo Clinic has increased the number of patients who can undergo operation.

Multi-parametric magnetic resonance imaging of liver regeneration in a standardized partial hepatectomy rat model

Background

We aimed to evaluate the correlation between the pathological changes and multi-parameter MRI characteristics of liver regeneration (LR) in a standard partial hepatectomy (PH) rat model.

Methods

Seventy Sprague–Dawley rats were randomly divided into two groups: MR scan group (n = 14) and pathologic analysis (PA) group (n = 56). All 14 rats in the MR group underwent liver T1 mapping, T2 mapping, and diffusion kurtosis imaging before and the 1st, 2nd, 3rd, 5th, 7th, 14th, and 21st day after 70% hepatectomy. Seven rats in the PA group were euthanized at each time point to determine Ki-67 indices, hepatocyte size (HTS), steatosis grade, and inflammation score.

Results

Liver T1 and T2 values increased to maximum on day 2 (P < 0.001 vs. baseline), D and K values decreased to minimum on day 3 and 2, respectively (P < 0.001 vs. baseline), then all parameters returned to baseline gradually. Hepatocyte Ki-67, hepatocyte size, steatosis grade, and inflammation score initially increased after surgery (P < 0.05 vs. baseline), followed by a gradual decline over time. Both T2 and K values correlated well with Ki-67 indices (r = 0.765 and − 0.807, respectively; both P < 0.001), inflammation (r = 0.809 and − 0.724, respectively; both P < 0.001), steatosis grade (r = 0.814 and − 0.725, respectively; both P < 0.001), and HTS (r = 0.830 and − 0.615, respectively; both P < 0.001).

Conclusions

PH induced liver changes that can be observed on MRI. The MRI parameters correlate with the LR activity and allow monitoring of LR process.

Portocaval shunt can optimize transhepatic flow following extended hepatectomy: a short-term study in a porcine model

The aim of this study was to evaluate whether the portocaval shunt (PCS) corrects these unwanted changes in transhepatic flow after extended hepatectomy (EH). Forty female Landrace pigs were divided into two main groups: (A) EH (75%) and (B) no EH. Group A was divided into 3 subgroups: (A1) EH without PCS; (A2) EH with side-to-side PCS; and (A3) EH with end-to-side PCS. Group B was divided into 2 subgroups: (B1) side-to-side PCS and (B2) end-to-side PCS. HAF, PVF, and PVP were measured in each animal before and after the surgical procedure. EH increased the PVF/100 g (173%, p < 0.001) and PVP (68%, p < 0.001) but reduced the HAF/100 g (22%, p = 0.819). Following EH, side-to-side PCS reduced the increased PVF (78%, p < 0.001) and PVP (38%, p = 0.001). Without EH, side-to-side PCS reduced the PVF/100 g (68%, p < 0.001) and PVP (12%, p = 0.237). PVP was reduced by end-to-side PCS following EH by 48% (p < 0.001) and without EH by 21% (p = 0.075). PCS can decrease and correct the elevated PVP and PVF/100 g after EH to close to the normal values prior to resection. The decreased HAF/100 g in the remnant liver following EH is increased and corrected through PCS.

Vascular Resection in Perihilar Cholangiocarcinoma

Among the cholangiocarcinomas, the most common type is perihilar (phCC), accounting for approximately 60% of cases, after which are the distal and then intrahepatic forms. There is no staging system that allows for a comparison of all series and extraction of conclusions that increase the long-term survival rate of this dismal disease. The extension of the resection, which theoretically depends on the type of phCC, is not a closed subject. As surgery is the only known way to achieve a cure, many aggressive approaches have been adopted. Despite extended liver resections and even vascular resections, margins are positive in around one third of patients. In the past two decades, with advances in diagnostic and surgical techniques, surgical outcomes and survival rates have gradually improved, although variability is the rule, with morbidity and mortality rates ranging from 14% to 76% and from 0% to 19%, respectively. Extended hepatectomies and portal vein resection, or even right hepatic artery reconstruction for the left side tumors are frequently needed. Salvage procedures when arterial reconstruction is not feasible, as well as hepatopancreatoduodenectomy, are still under evaluation too. In this article, we discuss the aggressive surgical approach to phCC focused on vascular resection. Disparate results on the surgical treatment of phCC made it impossible to reach clear-cut conclusions.

Muscularity Defined by the Combination of Muscle Quantity and Quality is Closely Related to Both Liver Hypertrophy and Postoperative Outcomes Following Portal Vein Embolization in Cancer Patients

BACKGROUND

Portal vein embolization (PVE) is a common procedure for preventing hepatic insufficiency after major hepatectomy. While evaluating the body composition of surgical patients is common, the impact of muscularity defined by both muscle quantity and quality on liver hypertrophy after PVE and associated outcomes after major hepatectomy in patients with hepatobiliary cancer remain unclear.

METHODS

This retrospective review included 126 patients who had undergone hepatobiliary cancer resection after PVE. Muscularity was measured on preoperative computed tomography images by combining the skeletal mass index and intramuscular adipose content. Various factors including the degree of hypertrophy (DH) of the future liver remnant and post-hepatectomy outcomes were compared according to muscularity.

RESULTS

DH did not differ by malignancy type. Patients with high muscularity had better DH after PVE (P = 0.028), and low muscularity was an independent predictor for poor liver hypertrophy after PVE [odds ratio (OR), 3.418; 95% confidence interval (CI), 1.129-10.352; P = 0.030]. In subgroup analyses in which patients were stratified into groups based on primary hepatobiliary tumors and metastases, low muscularity was associated with higher incidence of post-hepatectomy liver failure (PHLF) ≥ grade B (P = 0.018) and was identified as an independent predictor for high-grade PHLF (OR 3.931; 95% CI 1.113-13.885; P = 0.034) among the primary tumor group. In contrast, muscularity did not affect surgical outcomes in patients with metastases.

CONCLUSIONS

Low muscularity leads to poor liver hypertrophy after PVE and is also a predictor of PHLF, particularly in primary hepatobiliary cancer.

Improved liver function in patients with cirrhosis due to chronic hepatitis C virus who achieve sustained virologic response is not accompanied by increased liver volume

BACKGROUND

Serum albumin level improves in patients with chronic hepatitis C virus (HCV) infection who achieve sustained virologic response (SVR) with antiviral therapy. However, it remains controversial whether liver volume increases along with SVR.

METHODS

Patients with chronic HCV infection with a history of hepatocellular carcinoma (HCC) who achieved SVR with anti-HCV treatment from March 2003 to November 2017 were enrolled. Patients were followed up with periodic computed tomography (CT) scans to detect HCC recurrence. Patients who underwent treatment for HCC recurrence within 1 year after initiation of anti-HCV treatment were excluded. Laboratory data, including alanine aminotransferase (ALT) level, serum albumin level, and platelet count, were collected at baseline and timepoints after treatment initiation. Liver volume was evaluated at baseline and 24 and 48 weeks after treatment initiation using a CT volume analyzer. A linear mixed-effects model was applied to analyze the chronologic change in liver volume. The correlations between changes in ALT level, albumin level, and liver volume were also evaluated.

RESULTS

Of 108 enrolled patients, 78 had cirrhosis. Serum albumin level continued to increase through 48 weeks after treatment initiation. A significant increase in liver volume was observed only in patients without cirrhosis (P = 0.005). There was a significant correlation between ALT level decrease and albumin level increase (P = 0.018).

CONCLUSIONS

Improved liver albumin production with SVR was contributed by improved liver cell function rather than increased liver volume in patients with cirrhosis.

Feasibility of Reinstitution of CAPD after Partial Hepatectomy in Patients with Malignant Hepatic Tumors

Objective

To determine the feasibility of reinstitution of continuous ambulatory peritoneal dialysis (CAPD) in patients with malignant hepatic tumors after partial hepatectomy.

Design

Retrospective analysis of 2 CAPD patients.

Setting

Dialysis unit of a university teaching hospital.

Patients

Two CAPD patients with malignant hepatic tumors who had undergone partial hepatectomy.

Main Outcome Measures

Serum biochemistry, Kt/V, peritoneal equilibration test (PET) results before and after hepatectomy.

Results

One patient was able to resume CAPD 4 weeks after partial hepatectomy. The other patient was successfully resumed on CAPD after resting the peritoneum for 3 months following partial hepatectomy. The serum biochemistry, Kt/V, and PET results of the 2 patients did not change significantly before and after partial hepatectomy.

Conclusions

Reinstitution of CAPD after partial hepatectomy in patients with malignant hepatic tumors is feasible.

Evaluation of the role of transhepatic flow in postoperative outcomes following major hepatectomy (THEFLOW): study protocol for a single-centre, non-interventional cohort study

INTRODUCTION

Liver resection is the only curative treatment for primary and secondary hepatic tumours. Improvements in perioperative preparation of patients and new surgical developments have made complex liver resections possible. However, small for size and flow syndrome (SFSF) is still a challenging issue, rendering patients inoperable and causing postoperative morbidity and mortality. Although the role of transhepatic flow in the postoperative outcome has been shown in small partial liver transplantation and experimental studies of SFSF, this has never been studied in the clinical setting following liver resection. The aim of this study is to systematically evaluate transhepatic flow changes following major liver resection and its correlation with postoperative outcomes.

METHODS AND ANALYSIS

The TransHEpatic FLOW (THEFLOW) study is a single-centre, non-interventional cohort study, and aims to enrol 50 patients undergoing major hepatectomy (defined as hemihepatectomy or extended hepatectomy based on the Brisbane classification) with or without prior chemotherapy. The portal venous flow, hepatic artery flow and portal venous pressure are measured before and after each resection. All patients are followed-up for 3 months after the operation. During each evaluation, standard clinical data, posthepatectomy liver failure and overall morbidity and mortality will be recorded. THEFLOW study was initiated on 25 March 2018 and is expected to progress for 2 years.

ETHICS AND DISSEMINATION

This protocol study received approval from the Ethics Committee of the University of Heidelberg (registration number: S576/2017). The results of this study will be published in a peer-reviewed journal, and will also be presented at medical meetings.

TRIAL REGISTRATION NUMBER

NCT03762876.

Evaluation of liver regeneration and post-hepatectomy liver failure after hemihepatectomy in patients with hepatocellular carcinoma

Aim: To explore clinical factors associated with extent of liver regeneration after hemihepatectomy to treat hepatocellular carcinoma (HCC).Methods: Future liver remnant volume (as a percentage of functional liver volume, %FLRV) and remnant liver volume were measured preoperatively and at 1, 5, 9, and 13 weeks postoperatively.Results: After hepatectomy, 1 of 125 patients (0.8%) died within 3 months, 13 (10.4%) experienced liver failure, and 99 (79.2%) experienced complications. %FLRV was able to predict liver failure with an area under the receiver operating characteristic curve of 0.900, and a cut-off value of 42.7% showed sensitivity of 85.7% and specificity of 88.6%. Postoperative median growth ratio was 21.3% at 1 week, 30.9% at 5 weeks, 34.6% at 9 weeks, and 37.1% at 13 weeks. Multivariate analysis identified three predictors associated with liver regeneration: FLRV < 601 cm3, %FLRV, and liver cirrhosis. At postoperative weeks (POWs) 1 and 5, liver function indicators were significantly better among patients showing high extent of regeneration than among those showing low extent, but these differences disappeared by POW 9.Conclusions: FLRV, %FLRV, and liver cirrhosis strongly influence extent of liver regeneration after hepatectomy. %FLRV values below 42.7% are associated with greater risk of post-hepatectomy liver failure.

Ischemic complications after percutaneous radiofrequency ablation of liver tumors: Liver volume loss and recovery

AIM

The liver regrows after acute liver injury and liver resection. However, it is not clear whether the liver regenerates in advanced cirrhosis. This study aimed to evaluate the clinical course of, and liver volume change after, ischemic liver complications caused by radiofrequency ablation (RFA) of hepatocellular carcinoma (HCC).

METHODS

We enrolled 35 patients with ischemic complications after RFA. Ischemic complications were defined as rapid elevation of aspartate aminotransferase (AST) to over 500 U/L, with typical radiological findings. Patient characteristics and the ischemic liver volume were investigated. Long-term liver volume changes at 3-8 months after ischemic complications were also assessed in 32 patients. We also assessed the overall survival rate after ischemic complications.

RESULTS

The median value of peak AST was 798 U/L (range, 531-4096 U/L). The median ischemic liver volume relative to the functional liver volume before RFA was 13% (range, 3.1-46.5%). There was a strong correlation between the peak AST value and the ischemic liver volume (r = 0.84, P < 0.001). The liver volume recovered to some extent in 18 of 32 (56%) patients after ischemic complications. The survival rate after ischemic complications was 45.7% at 5 years and correlated with the functional liver volume after ischemic complications (P = 0.02).

CONCLUSIONS

Ischemic complications after RFA can lead to massive liver parenchymal loss. Although the liver volume recovered to some extent in the majority of our patients, ischemic liver complications after RFA should be avoided to improve the overall survival rate.

Multiple factors affect the regeneration of liver

OBJECTIVE

To study factors affecting the liver regeneration after hepatectomy.

METHODS

With 3D reconstitution technology, liver regeneration ability of 117 patients was analysed, and relative factors were studied.

RESULTS

There was no statistically difference between the volume of simulated liver resection and the actual liver resection. All livers had different degrees of regeneration after surgery. Age, gender and blood indicators had no impact on liver regeneration, while surgery time, intraoperative blood loss, blood flow blocking time and different ways of liver resection had a significant impact on liver regeneration; In addition, the patients' own pathological status, including, hepatitis and liver fibrosis all had a significant impact on liver regeneration.

CONCLUSION

3D reconstitution model is a good model to calculate liver volume. Age, gender, blood indicators and biochemistry indicators have no impact on liver regeneration, but surgery indicators and patients' own pathological status have influence on liver regeneration.

Compensatory hypertrophy of the liver after external beam radiotherapy for primary liver cancer

PURPOSE

We investigated whether external beam radiotherapy (EBRT) could induce compensatory liver hypertrophy in liver cancers and assessed related clinical factors.

METHODS

A total of 82 consecutive patients receiving EBRT for hepatocellular carcinoma (n = 77) or cholangiocarcinoma (n = 5) from April 2012 to June 2014 were recruited and divided into two subgroups according to tumor location in the right or left lobe. The left lateral and right lobes were considered as unirradiated volumes accordingly. Total liver volume (TLV), nontumor liver volume (NLV), left and right lobe whole volume (LLWV and RLWV, respectively), volume of liver irradiated < 30 Gy (V_< 30 Gy), Child-Pugh (CPS) score, future liver remnant (FLR) ratio, and percentage of FLR hypertrophy from baseline (%FLR) were assessed.

RESULTS

In the right lobe group, %FLR hypertrophy and LLWV increased significantly at all follow-ups (p < 0.001). %FLR hypertrophy steadily increased until the fourth follow-up. Multivariate analysis showed that the factor associated with maximum %FLR hypertrophy was tumor extent (upper or lower lobe vs. both lobes; p = 0.022). Post-RT treatments including transarterial chemoembolization or hepatic arterial infusion chemotherapy were associated with a CPS increase ≥ 2 (p = 0.002). Analysis of the RT only subgroup also showed a significant increase of %FLR until the fourth follow-up (p < 0.001). In the left lobe group, %FLR hypertrophy and RLWV showed no significant changes during follow-up.

CONCLUSION

Significant compensatory hypertrophy of the liver was observed, with a steady increase of %FLR hypertrophy until the fourth follow-up (median: 396 days). Locally advanced tumors extending across the upper and lower right lobe were a significant factor for compensating hypertrophy after EBRT.

Predicting post-hepatectomy liver failure by combined volumetric, functional MR image and laboratory analysis

BACKGROUND & AIMS

To assess the efficacy of functional MR image with volumetric, liver function test and indocyanine green clearance (ICG) in identifying the patients who are at risk of post-hepatectomy liver failure (PHLF).

METHODS

We retrospectively included 115 patients undergoing gadoxetic acid-enhanced MR imaging before hepatectomy at one medical centre from January 2013 to December 2015. Contrast enhancement ratio (CER) between transitional and hepatobiliary phases (3 and 30 minutes post-contrast) was calculated. Total liver volume (TLV) and spleen volume (Sp) were measured. Post-operatively, the histological Ishak fibrosis score was collected. Potential risk factors for liver failure were analysed, and the performance was examined by receiver operating characteristic curve.

RESULTS

Post-hepatectomy liver failure (PHLF) occurred in 16 patients (13.9%). TLV/SLV, ADC value, CER_HBP/TP and total liver contrast enhancement ratio (tCER) were associated with PHLF (P < .05). Between PHLF and non-PHLF groups, remnant liver volume (RLV), RLV/SLV, Sp/RLV, remnant liver contrast enhancement ratio (rCER) and Ishak fibrosis score showed statistical difference. rCER showed superiority in diagnostic performance (AUC = 0.78) with the optimal cut-off value of 1.23.

CONCLUSIONS

Gadoxetic acid-enhanced MR imaging with volumetric is a reliable method for evaluating functional liver volume and determining the risk of PHLF.

Portal vein embolization with n-butyl-cyanoacrylate through an ipsilateral approach before major hepatectomy: single center analysis of 50 consecutive patients

Purpose

To evaluate the efficacy of portal vein embolization (PVE) with n-Butyl-cyanoacrylate (NBCA) through an ipsilateral approach before major hepatectomy. Secondary end-points were PVE safety, liver resection and patient outcome.

Methods

Over a 5-year period 50 non-cirrhotic consecutive patients were included with primary or secondary liver cancer treatable by hepatectomy with a liver remnant (FLR) volume less than 25% or less than 40% in diseased livers.

Results

There were 37 men and 13 women with a mean age of 57 years. Colorectal liver metastases were the most frequent tumor and patients were previously exposed to chemotherapy. FLR increased from 422 ml to 629 ml (P < 0.001) after PVE, corresponding to anincrease of 52%. The FLR ratio increased from 29.6% to 42.3% (P < 0.001). Kinetic growth rate was 2.98%/week. A negative association was observed between increase in the FLR and FLR ratio and FLR volume before PVE (P = 0.002). In 31 patients hepatectomy was accomplished and only one patient presented with liver insufficiency within 30 days after surgery.

Conclusions

PVE with NBCA through an ipsilateral puncture is effective before major hepatectomy. Meticulous attention is needed especially near the end of the embolization procedure to avoid complications.

Trial registration

Clinical Study ISRCTN registration number: ISRCTN39855523. Registered March 13th 2017.

Prediction of postoperative liver regeneration from clinical information using a data-led mathematical model

Although the capacity of the liver to recover its size after resection has enabled extensive liver resection, post-hepatectomy liver failure remains one of the most lethal complications of liver resection. Therefore, it is clinically important to discover reliable predictive factors after resection. In this study, we established a novel mathematical framework which described post-hepatectomy liver regeneration in each patient by incorporating quantitative clinical data. Using the model fitting to the liver volumes in series of computed tomography of 123 patients, we estimated liver regeneration rates. From the estimation, we found patients were divided into two groups: i) patients restored the liver to its original size (Group 1, n = 99); and ii) patients experienced a significant reduction in size (Group 2, n = 24). From discriminant analysis in 103 patients with full clinical variables, the prognosis of patients in terms of liver recovery was successfully predicted in 85-90% of patients. We further validated the accuracy of our model prediction using a validation cohort (prediction = 84-87%, n = 39). Our interdisciplinary approach provides qualitative and quantitative insights into the dynamics of liver regeneration. A key strength is to provide better prediction in patients who had been judged as acceptable for resection by current pragmatic criteria.

Impact of Perioperative Phosphorus and Glucose Levels on Liver Regeneration and Long-term Outcomes after Major Liver Resection

INTRODUCTION

The impact of phosphorus as well as glycemic alterations on liver regeneration has not been directly examined. We sought to determine the impact of phosphorus and glucose on liver regeneration after major hepatectomy.

METHODS

Early and late liver regeneration index was defined as the relative increase of liver volume (RLV) within 2[(RLV2m-RLVp)/RLVp] and 7 months[(RLV7m-RLVp)/RLVp] following surgery. The association of perioperative metabolic factors, liver regeneration, and outcomes was assessed.

RESULTS

On postoperative day 2, 50 (52.6 %) patients had a low phosphorus level (≤2.4 mg/dl), while 45 (47.4 %) had a normal/high phosphorus level (>2.4 mg/dl). Despite comparable clinicopathologic characteristics (all P > 0.05) and RLV/TLV at surgery (P = 0.84), regeneration index within 2 months was lower in the normal/high phosphorus group (P = 0.01) with these patients having increased risk for postoperative liver failure (P = 0.01). The inhibition of liver regeneration persisted at 7 months (P = 0.007) and was associated with a worse survival (P = 0.02). Preoperative hypoglycemia was associated only with a lower early regeneration index (P = 0.02).

CONCLUSIONS

Normal/high phosphorus was associated with inhibition of early and late liver regeneration, as well as with an increased risk of liver failure and worse long-term outcomes. Immediate preoperative hypoglycemia was associated with a lower early volumetric gain. Metabolic factors may represent early indicators of liver failure that could identify patients at increased risk for worse outcomes.

Small for Size and Flow (SFSF) syndrome: An alternative description for posthepatectomy liver failure

Small for Size Syndrome (SFSS) syndrome is a recognizable clinical syndrome occurring in the presence of a reduced mass of liver, which is insufficient to maintain normal liver function. A definition has yet to be fully clarified, but it is a common clinical syndrome following partial liver transplantation and extended hepatectomy, which is characterized by postoperative liver dysfunction with prolonged cholestasis and coagulopathy, portal hypertension, and ascites. So far, this syndrome has been discussed with focus on the remnant size of the liver after partial liver transplantation or extended hepatectomy. However, the current viewpoints believe that the excessive flow of portal vein for the volume of the liver parenchyma leads to over-pressure, sinusoidal endothelial damages and haemorrhage. The new hypothesis declares that in both extended hepatectomy and partial liver transplantation, progression of Small for Size Syndrome is not determined only by the "size" of the liver graft or remnant, but by the hemodynamic parameters of the hepatic circulation, especially portal vein flow. Therefore, we suggest the term "Small for Size and Flow (SFSF)" for this syndrome. We believe that it is important for liver surgeons to know the pathogenesis and manifestation of this syndrome to react early enough preventing non-reversible tissue damages.

Analysis of the relationship between liver regeneration rate and blood levels

OBJECTIVES

The aim of this study was to investigate the difference of liver function changes according to the liver regeneration rate after liver transplantation through blood tests.

METHODS

Fifty donors, who underwent computed tomography (CT) 3D volumetry, were analyzed before and after liver transplantation. CT 3D volumetry was used as a study method to measure the mean liver regeneration volume and regeneration rate. Then, blood levels were measured including alanine transaminase (ALT), aminotransferase (AST), gamma-glutamyl transpeptidase (GGT) and total bilirubin.

RESULTS

The liver regeneration rate rapidly increased from 39.13±4.91% befoone1 month and 90.31±13.09% 16 months after surgery furthermore. Blood levels rapidly increased 7 days after surgery and then decreased 16 months after surgery compared to the state before surgery.

CONCLUSION

This study results could be used as a basis for the prognosis of future liver transplantations.

Volume regeneration of segments 2 and 3 after right portal vein embolization in patients undergoing two-stage hepatectomy

BACKGROUND

The impact of first-stage resection on volume regeneration of segments 2 and 3 (2 + 3) after right portal vein embolization (RPVE) in patients undergoing two-stage right hepatectomy has not been investigated.

METHOD

Volume data for segments 2 + 3 were compared between 44 patients undergoing two-stage hepatectomy and 116 undergoing single-stage hepatectomy after RPVE.

RESULTS

The degree of hypertrophy (difference between standardized volume of segments 2 + 3 before and after RPVE) and kinetic growth rate (degree of hypertrophy at initial volume assessment divided by the number of weeks elapsed after RPVE) were significantly lower in patients undergoing two-stage hepatectomy (median 8.6 vs 10.5% [p = 0.01] and 1.7 vs 2.4% [p < 0.01], respectively). Resection volume during first-stage resection was negatively correlated with standardized volume increase from the volume before first-stage resection (R (2) 0.546, p < 0.01). In patients undergoing two-stage hepatectomy after RPVE with segment 4 embolization, the degree of hypertrophy and kinetic growth rate were similar to those in patients undergoing single-stage hepatectomy (p = 0.17 and p = 0.08, respectively).

CONCLUSION

In patients undergoing two-stage hepatectomy, first-stage resection impairs the dynamics of volume regeneration of segments 2 + 3 after RPVE. When two-stage extended right hepatectomy is planned, additional embolization of segment 4 provides volume hypertrophy similar to that in patients undergoing single-stage hepatectomy.

Liver planning software accurately predicts postoperative liver volume and measures early regeneration

BACKGROUND

Postoperative or remnant liver volume (RLV) after hepatic resection is a critical predictor of perioperative outcomes. This study investigates whether the accuracy of liver surgical planning software for predicting postoperative RLV and assessing early regeneration.

STUDY DESIGN

Patients eligible for hepatic resection were approached for participation in the study from June 2008 to 2010. All patients underwent cross-sectional imaging (CT or MRI) before and early after resection. Planned remnant liver volume (pRLV) (based on the planned resection on the preoperative scan) and postoperative actual remnant liver volume (aRLV) (determined from early postoperative scan) were measured using Scout Liver software (Pathfinder Therapeutics Inc.). Differences between pRLV and aRLV were analyzed, controlling for timing of postoperative imaging. Measured total liver volume (TLV) was compared with standard equations for calculating volume.

RESULTS

Sixty-six patients were enrolled in the study from June 2008 to June 2010 at 3 treatment centers. Correlation was found between pRLV and aRLV (r = 0.941; p < 0.001), which improved when timing of postoperative imaging was considered (r = 0.953; p < 0.001). Relative volume deviation from pRLV to aRLV stratified cases according to timing of postoperative imaging showed evidence of measurable regeneration beginning 5 days after surgery, with stabilization at 8 days (p < 0.01). For patients at the upper and lower extremes of liver volumes, TLV was poorly estimated using standard equations (up to 50% in some cases).

CONCLUSIONS

Preoperative virtual planning of future liver remnant accurately predicts postoperative volume after hepatic resection. Early postoperative liver regeneration is measureable on imaging beginning at 5 days after surgery. Measuring TLV directly from CT scans rather than calculating based on equations accounts for extremes in TLV.

Systematic review of pathophysiological changes following hepatic resection

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Mechanisms of splenic hypertrophy following hepatic resection

BACKGROUND

Following hepatic resection, liver regeneration has been associated with concurrent splenic hypertrophy. The mechanisms of this phenomenon are unknown, may be multiple and include: splanchnic sequestration caused by a reduction in the hepatic mass; hepatic growth factors that may indirectly act on the spleen, and the redistribution of the total reticuloendothelial system.

METHODS

Seventy-five patients (40 males; median age: 60 years) who underwent minor (16%) or major (84%) hepatectomy between September 2004 and October 2009 were included. Prospective measurements of liver and spleen volumes were obtained preoperatively and postoperatively 1 month after hepatectomy using computed tomography (CT). The future remnant liver volume (RLV) was calculated on preoperative CT and the extent of resection was expressed as the RLV divided by total liver volume (TLV). Liver and spleen hypertrophy were expressed according to the absolute gain or relative increase in the initial volumes (%).The presence of fibrosis >F1, associated extrahepatic resection (except minor resections), and previous hepatectomy (major or minor) within 3 months represented exclusion criteria.

RESULTS

Mean ± standard deviation (SD) liver volume at 1 month was higher than RLV (1187 ± 286 cm(3) versus 764 ± 421 cm(3) ; P < 0.001). Mean ± SD splenic volume increased from 252 ± 100 cm(3) preoperatively to 300 ± 111 cm(3) at 1 month (P < 0.001). Liver and splenic hypertrophy were significant after major hepatectomies (+100% and +26%, respectively; P < 0.001), but not after minor hepatectomies. Liver hypertrophy was inversely correlated to RLV/TLV (r = -0.687, P < 0.001). Splenic hypertrophy was not correlated to RLV/TLV. Liver and splenic hypertrophy were linearly correlated (r = 0.495, P < 0.001). Neoadjuvant chemotherapy (n = 37), preoperative portal vein embolization (n = 10) and postoperative complications (overall: n = 25; major: n = 10; infectious: n = 6) had no impact on hepatic or splenic hypertrophy.

CONCLUSIONS

Splenic hypertrophy occurred after major hepatectomy, but was not correlated to the extent of resection, by contrast with liver hypertrophy. Nevertheless, there was a linear correlation between splenic and liver hypertrophy. This correlation suggests the hypothesis of a splenic action of hepatic growth factors or a redistribution of the total reticuloendothelial system rather than an effect of reduction of the portal bed or hepatic outflow.

Limiting factors for liver regeneration after a major hepatic resection for colorectal cancer metastases

BACKGROUND

Chemotherapy before resection of colorectal metastases in the liver is extensively used and has been shown to induce histopathological changes in the liver parenchyma, although little is known about the effect of chemotherapy on liver regeneration. The aim of this study was to determine if pre-operative chemotherapy influences the regenerated liver volume after a major liver resection.

PATIENTS AND METHODS

This retrospective cohort study included 74 patients subjected to a major liver resection for colorectal metastases. Patients were divided into two groups depending on whether they had been treated with chemotherapy less than 3 months before surgery or not. Liver volumes were measured before and 1 year after resection.

RESULTS

Pre-operative chemotherapy reduced volumetric liver regeneration (83 ± 2% versus 91 ± 2%; P = 0.007) as compared with patients without chemotherapy. There was a linear correlation between regenerated volume and time interval between the end of chemotherapy to resection (P = 0.031).

CONCLUSIONS

Pre-operative chemotherapy in patients with colorectal liver metastases negatively affects volume regeneration after a partial hepatectomy. The time interval between chemotherapy and surgery determines the impact of these affects.

Percentage of future liver remnant volume before portal vein embolization influences the degree of liver regeneration after hepatectomy

BACKGROUND

Clinical determinants of liver regeneration induced by portal vein embolization (PVE) and hepatectomy remain unclear. The aims of this study were to investigate how liver regeneration occurs after PVE followed by hepatectomy and to determine which factors strongly promote liver regeneration.

METHODS

Thirty-six patients who underwent both preoperative PVE and major hepatectomy were enrolled in this study. Percentage of future liver remnant volume before PVE (%FLR-pre) was compared with the remnant liver volume after PVE (%FLR-post-PVE) and on postoperative day 7 after hepatic resection (%FLR-post-HR). Clinical indicators contributing to liver regeneration induced by both PVE and hepatectomy were examined by logistic regression analysis.

RESULTS

PVE and hepatectomy caused a two-step regeneration. FLR-pre, FLR-post-PVE, and FLR-post-HR were 448, 579, and 761 cm(3), respectively. The %FLR-pre was significantly associated with liver regeneration induced by both PVE and hepatectomy (r = 0.63, p < 0.0001). Multiple regression analysis showed that only %FLR-pre was independently correlated with posthepatectomy liver regeneration (p = 0.027, odds ratio = 13.8).

CONCLUSION

After PVE and the subsequent hepatectomy, liver regeneration was accomplished in a two-step manner. Liver regeneration was strongly influenced by the %FLR-pre.

Systematic review and meta-analysis of the role of vascular resection in the treatment of hilar cholangiocarcinoma

BACKGROUND

The management of hilar cholangiocarcinoma has evolved over time and extended liver resection, including the caudate lobe, and major vascular resection and extended lymphadenectomy have become established practice. The benefit of vascular resection has not been investigated.

METHODS

A systematic search of the MEDLINE and EMBASE databases was used to identify studies. A systematic review and a meta-analysis of the available studies were conducted according to PRISMA guidelines. Odds ratios were calculated using the Mantel-Haenszel method. Primary outcome variables assessed included morbidity, mortality, vascular complications and the effect of vascular resection on longterm survival.

RESULTS

Of 411 search results, only 24 studies reported the results of vascular resection in hilar cholangiocarcinoma. Meta-analysis showed increased morbidity and mortality with hepatic artery resection. Portal vein resection was achievable with no impact on postoperative mortality. Vascular resection did not improve negative margin rates and had no impact on longterm survival.

CONCLUSIONS

Portal vein resection does not preclude curative resection; however, it is not routinely recommended unless there is suspicion of tumour invasion. There was no proven survival advantage with portal vein resection. Arterial resection results in higher morbidity and mortality with no proven benefit.

Difference of regeneration potential between healthy and diseased liver

BACKGROUND

We sought to evaluate total and segmental liver regeneration by comparing preoperative computed tomographic (CT) volumetry and CT volumetry on postoperative day (POD) 7 after a right hepatectomy, in patients with various status and surgical indications.

METHOD

We included 36 patients who underwent right lobectomy for living donor liver transplantation (healthy group), and 29 for hepatocellular carcinoma treatment (disease group). All of the disease group patients were Child-Turcotte-Pugh (CTP) class A. The regeneration of lateral, medial segment and total remnant liver volumes were assessed on POD 7 using a CT-based program. Total volumes and segmental volumes were measured for total liver, future liver remnant (FLR), and liver remnant. We calculated total and segmental early regeneration indexes, defined as [(VLR-VFLR)/VFLR]×100, where VLR is volume of the liver remnant and VFLR is volume of the FLR.

RESULT

The VLR at POD 7 showed a 72.9% increase in volume among the healthy versus 55% in the disease group, (P=.012) In the disease group, segmental volume and regeneration indexes were also significantly lower than among the healthy group: 59.0% versus 46.9% in the medial and 86.8% versus 57.7% in the lateral segment (P=.023 and P<.001) respectively.

CONCLUSION

The volume regeneration potential in diseased livers is significantly lower than that of a normal, healthy liver. So, we must consider a patient's liver status and volume profile before an extensive liver.

Function and volume recovery after partial hepatectomy: influence of preoperative liver function, residual liver volume, and obesity

BACKGROUND

The regenerative capacity of the liver is an essential pre-condition for the successful application of partial hepatectomy. However, the actual kinetics of functional recovery remains unspecified and no adequate tool for its clinical monitoring has yet been available.

METHODS

Eighty-five patients receiving major hepatectomy were investigated from the preoperative evaluation until 12 weeks after surgery. Liver function was determined by the LiMAx test for the enzymatic capacity of cytochrome P450 1A2. Liver volume was determined by volumetric analysis of repeated computer tomography scans. Functional and volume recovery were compared during follow-up.

RESULTS

Major hepatectomy decreased liver function capacity to 35.7 ± 13.8% of preoperative function. It was shown that functional recovery already reaches 77.2 ± 33.5% of preoperative values within 10 days. The actual kinetics were dependent from the type and extent of hepatectomy. Complete functional restoration was achieved within 12 weeks, while liver volume still remained at 73.2 ± 14.8% of preoperative. A constant but interindividually variable correlation between function and volume was observed at all points in time.

CONCLUSION

Partial hepatectomy leads to fast and complete functional recovery, while volume recovery is delayed and remains often incomplete. The functional recovery is mainly influenced by the preoperative liver function, the residual liver volume, and by obesity.

Three dimensional cultures of rat liver cells using a natural self-assembling nanoscaffold in a clinically relevant bioreactor for bioartificial liver construction

Till date, no bioartificial liver (BAL) procedure has obtained FDA approval or widespread clinical acceptance, mainly because of multifactorial limitations such as the use of microscale or undefined biomaterials, indirect and lower oxygenation levels in liver cells, short-term undesirable functions, and a lack of 3D interaction of growth factor/cytokine signaling in liver cells. To overcome preclinical limitations, primary rat liver cells were cultured on a naturally self-assembling peptide nanoscaffold (SAPN) in a clinically relevant bioreactor for up to 35 days, under 3D interaction with suitable growth factors and cytokine signaling agents, alone or combination (e.g., Group I: EPO, Group II: Activin A, Group III: IL-6, Group IV: BMP-4, Group V: BMP4 + EPO, Group VI: EPO + IL-6, Group VII: BMP4 + IL-6, Group VIII: Activin A + EPO, Group IX: IL-6 + Activin A, Group X: Activin A + BMP4, Group XI: EPO + Activin A + BMP-4 + IL-6 + HGF, and Group XII: Control). Major liver specific functions such as albumin secretion, urea metabolism, ammonia detoxification, phase contrast microscopy, immunofluorescence of liver specific markers (Albumin and CYP3A1), mitochondrial status, glutamic oxaloacetic transaminase (GOT) activity, glutamic pyruvic transaminase (GPT) activity, and cell membrane stability by the lactate dehydrogenase (LDH) test were also examined and compared with the control over time. In addition, we examined the drug biotransformation potential of a diazepam drug in a two-compartment model (cell matrix phase and supernatant), which is clinically important. This present study demonstrates an optimized 3D signaling/scaffolding in a preclinical BAL model, as well as preclinical drug screening for better drug development.

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.

New staging system and a registry for perihilar cholangiocarcinoma

Perihilar cholangiocarcinoma is one of the most challenging diseases with poor overall survival. The major problem for anyone trying to convincingly compare studies among centers or over time is the lack of a reliable staging system. The most commonly used system is the Bismuth-Corlette classification of bile duct involvement, which, however, does not include crucial information such as vascular encasement and distant metastases. Other systems are rarely used because they do not provide several key pieces of information guiding therapy. Therefore, we have designed a new system reporting the size of the tumor, the extent of the disease in the biliary system, the involvement of the hepatic artery and portal vein, the involvement of lymph nodes, distant metastases, and the volume of the putative remnant liver after resection. The aim of this system is the standardization of the reporting of perihilar cholangiocarcinoma so that relevant information regarding resectability, indications for liver transplantation, and prognosis can be provided. With this tool, we have created a new registry enabling every center to prospectively enter data on their patients with hilar cholangiocarcinoma (www.cholangioca.org). The availability of such standardized and multicenter data will enable us to identify the critical criteria guiding therapy.

Predictive factors for hypertrophy of the future remnant liver after selective portal vein embolization

BACKGROUND

To analyze predictive factors of hypertrophy of the nonembolized future remnant liver (FRL) after transhepatic preoperative portal vein embolization (PVE) of the liver to be resected.

MATERIALS AND METHODS

Age, gender, indocyanin green clearance test, chemotherapy before PVE, type of chemotherapy, operators, extent of PVE, radiofrequency ablation (RFA) associated with PVE, time delay between PVE and surgery, and platelet count were retrospectively evaluated as predictive factors for hypertrophy of FRL in 107 patients with malignant disease in noncirrhotic liver. PVE targeted the right liver lobe [n = 70] or the right liver lobe and segment IV [n = 37] when FRL/total liver volume ratio was below 25% in healthy liver or 40% in altered liver.

RESULTS

After PVE, FRL volume significantly increased by 69%, from 344 +/- 156 cm(3) to 543 +/- 192 cm(3) (P < .0001). The degree of hypertrophy was negatively correlated with FRL volume (correlation coefficient = -0.55, P < .0001) and FRL/TFL ratio (correlation coefficient = -0.52, P < .0001) before PVE. Patients, who have undergone chemotherapy with platin agents prior to PVE, demonstrated lower hypertrophy (P = .048).

CONCLUSION

Hypertrophy after PVE is inversely correlated to initial FRL volume. Hypertrophy of the liver might be influenced by the systemic chemotherapeutic received before PVE.

Liver regeneration at day 7 after right hepatectomy: global and segmental volumetric analysis by using CT

PURPOSE

To evaluate total and segmental liver regeneration by comparing preoperative computed tomographic (CT) volumetry and CT volumetry on postoperative day 7 following right hepatectomy and to study liver regeneration estimated by using CT volumetry in patients with different surgical indications and in whom the middle hepatic vein (MHV) was harvested or not harvested.

MATERIALS AND METHODS

Local medical ethics committee and state medical board approval and informed consent were obtained. Twenty-seven patients who had undergone right hepatectomy were imaged with multidetector CT preoperatively and at day 7 postoperatively. Fourteen patients (group 1) were living liver donors, including eight in whom the MHV was harvested. Thirteen patients (group 2) underwent right hepatectomy for other indications. Volumetric measurements were performed semiautomatically. Total volumes and segmental volumes were measured for total liver, future liver remnant (FLR), and liver remnant. Total and segmental early regeneration index, defined as [(V(LR) - V(FLR))/V(FLR)] x 100, where V(LR) is volume of the liver remnant and V(FLR) is volume of the FLR, were calculated. Comparisons were performed by using the Mann-Whitney test, and a P value of less than .05 was considered significant.

RESULTS

The liver remnant at day 7 showed a 64% increase in volume from the FLR, without a significant difference between groups 1 and 2. In the group with harvesting of MHV, volume and segmental regeneration index were significantly lower than in other patients, for both the caudate lobe (32 and 48 mL, respectively; P = .049) and liver segment IV (Couinaud) (206 and 334 mL, respectively; P = .008).

CONCLUSION

Segmental regeneration of the liver following right hepatectomy varies, depending on whether the MHV was harvested, and seems to be related to hepatic outflow.

Does adjuvant radiotherapy suppress liver regeneration after partial hepatectomy?

PURPOSE

To analyze the influence of the adjuvant radiotherapy (RT) on the liver regeneration and liver function after partial hepatectomy (PH).

METHODS AND MATERIALS

Thirty-four patients who underwent PH for biliary tract cancer between October 2003 and July 2005 were reviewed. Hemihepatectomy was performed in 14 patients and less extensive surgery in 20. Of the patients, 19 patients had no adjuvant therapy (non-RT group) and 15 underwent adjuvant RT by a three-dimensional conformal technique (RT group). Radiation dose range was 40 to 50 Gy (median, 40 Gy). Liver volume on computed tomography and the results of liver function tests at 1, 4, 12, 24, and 52 weeks after PH were compared between the RT and non-RT groups.

RESULTS

The preoperative characteristics were identical for both groups. During the interval between Weeks 4 and 12 when adjuvant RT was delivered in the RT group, the increase in liver volume was significantly smaller in the RT group than non-RT group (22.9 +/- 38.3cm(3) and 81.5 +/- 75.6cm(3), respectively, p = 0.007). However, the final liver volume measured at 1 year after PH did not differ between the two groups (p = 0.878). Liver function tests were comparable for both groups. The resection extent and original liver volume was independent factors for final liver volume measured at 1 year after PH.

CONCLUSIONS

In this study, adjuvant RT delayed the liver regeneration process after PH, but the volume difference between the two study groups became nonsignificant after 1 year. Adjuvant RT had no additional adverse effect on liver function after PH.

Auxiliary transplantation for acute liver failure: Histopathological study of native liver regeneration

Auxiliary liver transplantation (ALT) permits the serial assessment of regeneration in livers of patients with acute liver failure (ALF). Forty-nine ALF patients [32 adults (median age, 23 years; range, 16-40 years) and 17 children (median age, 12 years; range, 1-15 years)] underwent ALT between 1994 and 2004 at King's College Hospital. Twenty-four patients had seronegative liver failure, 15 had acetaminophen toxicity, 4 had hepatitis B virus (HBV) infection, 3 had drug-induced liver failure, 2 had autoimmune hepatitis, and 1 had mushroom poisoning. Nine patients without post-ALT native liver histology were excluded from review. All acetaminophen-induced, HBV, and drug-related patients had diffuse injury. Twelve seronegative patients and the autoimmune hepatitis patient had a map-like injury. On follow-up, 9 acetaminophen-induced patients, 9 seronegative patients, 2 drug-induced ALF patients, 3 HBV patients, and the autoimmune patient recovered to a near-normal native liver with inconsequential scarring. The hepatocyte proliferative rate in diffuse necrosis was 27.4% (range, 3.1%-69.4%) at hepatectomy and sharply decreased after 8 days post-ALT, being minimal months and years after ALT. In conclusion, in patients undergoing ALT for ALF with a diffuse pattern of liver injury-mainly acetaminophen toxicity-hepatocyte proliferation occurs in the native liver within a few days of transplantation. If the injury is map-like (most cases of seronegative ALF), regeneration seems to involve variable hepatocellular proliferation and potential ductular hepatopoiesis, but sequential assessment is difficult because of sampling variation. The likelihood of histological recovery appears to be minimal in livers with total hepatocyte loss at the time of ALT.

Postoperative biochemical liver function after major hepatic resection in children

BACKGROUND/PURPOSE

There are no detailed reports of the profile of biochemical liver function tests (LFTs) after partial hepatectomy in children. The study aims to establish normal profiles of standard LFTs after major liver resection in noncirrhotic children; the effects of preoperative chemotherapy were also analyzed.

METHODS

Clinical and biochemical data were collected from a consecutive series of children who had undergone a primary major liver resection for a hepatic tumor. Chemotherapy details were recorded. Children who had more than 4 liver segments resected were compared with those undergoing lesser resections. Those with and without preoperative chemotherapy were also compared.

RESULTS

A total of 22 children underwent major liver resection at a median age of 24 months (range, 2 weeks to 16 years). Fifteen received preoperative chemotherapy. Peak derangements in all standard LFTs occurred on day 1 to day 2 postoperatively. Normal plasma levels of bilirubin and albumin were present by day 5, international normalized ratio and alkaline phosphatase by day 7, and alanine aminotransferase by 1 to 2 weeks. Peak alanine aminotransferase and international normalized ratio values tended to be higher in children having more extensive liver resections. Preoperative chemotherapy given up to 3 weeks before surgery had no major effect on LFT recovery profiles. Hypophosphatemia was maximal on day 2.

CONCLUSIONS

Postoperative LFTs showed a more rapid resolution than typically seen after partial hepatectomy in adults. Preoperative chemotherapy had no major effects on postresection LFT profiles.

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.

Computed tomography volumetric follow-up of graft volume in living related liver recipients

AIM

Liver regeneration is a fascinating process that makes living related donor transplantation feasible for patients. In this study we evaluated the changes in graft volumes among living related liver transplantation (LRLT) patients using computerized tomography (CT)-assisted volumetry technique.

MATERIALS AND METHODS

Thirty three patients (17 adults, 16 children) who underwent liver transplantation were included in this study. Pediatric patients were referred to as group A, and adult patients were referred to as group B. The initial graft weight measured during operation was used as the initial graft volume. All patients' graft volumes were retrospectively calculated by CT volumetry technique. The data was compared with the initial graft volume in each patient. Paired samples Student t test was used for statistical analyses.

RESULTS

The graft volume increased from 2.7% to 285.6% with the mean increase 78% in group A, and 10.5% to 150.8% with a mean increase of 89% in group B. These changes were significant (P<.0001) in both groups.

DISCUSSION

The liver regeneration of recipient grafts is more complicated than that of the donors. There are a limited number of reports of complete volume recovery. We observed significant volume regeneration in liver grafts after transplantation, which was easily followed by CT-assisted volumetry.

Regeneration after two-stage hepatectomy vs. repeat resection for colorectal metastasis recurrence

BACKGROUND

Two-stage hepatectomy aims to minimize liver failure risk by performing a second resection after regeneration, assuming that remnant liver hypertrophy after the second resection is similar to that seen in repeat hepatectomy, yet the impact of a two-stage strategy on liver volume and function remains to be demonstrated.

PATIENTS AND METHODS

Twenty patients undergoing two-stage hepatectomy for multiple colorectal cancer metastases and 21 patients with more than two sections of liver parenchyma totally removed by repeat liver resections for recurrence were enrolled. Liver volumes after final hepatectomy and postoperative liver function were compared.

RESULTS

Median total liver volumes before initial hepatectomy and after final hepatectomy of multiple resections were 942 and 863 ml in patients with repeat hepatectomy, whereas volumes at corresponding time points were 957 and 777 ml in patients with two-stage hepatectomy. The ratio of total liver volume after both hepatectomies to preoperative volume in the two-stage group (81.7%) was lower than that in the repeat resection group (92.0%, P = 0.027). Greater aspartate aminotransferase and prothrombin time and lower platelet count 1 month postoperatively and lower albumin at 6 months were evident after two-stage hepatectomy compared with repeat hepatectomy.

CONCLUSIONS

Two-stage hepatectomy is characterized by diminished hepatic regenerative capacity and postoperative liver function.

Mechanism of impaired hepatic regeneration in cholestatic liver

The regenerative capacity of the liver is an important factor following liver surgery. The dramatic change in portal venous flow, due to either portal vein embolization or partial hepatectomy, induces a rapid change in liver volume. In response to these stresses, hepatocytes are primed, through the release of inflammatory cytokines, to increase the expression of immediate early genes and increase the activation of transcriptional factors. The primed hepatocytes then respond to growth factors, including hepatocyte growth factor, epidermal growth factor, and transforming growth factor-alpha. Several pathologic conditions have been shown to inhibit hepatic regeneration. These include diabetes mellitus, malnutrition, aging, infection, chronic ethanol consumption, and biliary obstruction. Impaired hepatic regeneration in the setting of biliary obstruction is an especially serious problem because it can be a major determinant in not considering surgical treatment. The mechanism responsible for impaired hepatic regeneration in patients with biliary obstruction includes decreased portal venous flow, attenuated production of liver proliferation-associated factors, an increased rate of apoptosis, and lack of enterohepatic circulation. Restoring these factors may lead to an improvement in regeneration in a cholestatic liver following portal vein embolization or partial hepatectomy. This review article summarizes the current understanding of the mechanism of hepatic regeneration, with particular emphasis on that in the cholestatic liver.

Disruption of the Middle Hepatic Vein is not Crucial for Liver Regeneration of the Remnant Liver After Right Hemihepatectomy for Hepatic Tumors

BACKGROUND

To clarify the role of the middle hepatic vein (MHV) in liver regeneration of the remnant liver after right hemihepatectomy for hepatic tumors, we reviewed 29 patients to evaluate liver regeneration for up to 12 postoperative months.

METHODS

Volume regeneration of the remnant liver was investigated by computed tomography at 3, 6, and 12 postoperative months. The remnant liver was divided into the following three areas: the medial section (segment IV), the lateral section (segments II and III), and segment I. The patients were divided into two groups: group A (n = 17), in which the MHV was preserved in the remnant liver, and group B (n = 12), in which the MHV was removed.

RESULTS

Volume regeneration of each area continued until 6 postoperative months but did not increase thereafter. On univariate analysis, differences in the volume regeneration of each area between the groups were not significant at any measured time point. Furthermore, disruption of the MHV was determined to not be crucial to the volume regeneration of any liver area on multivariate analysis. Only the resection volume (percentage) significantly affected liver regeneration of the remnant liver.

CONCLUSIONS

Disruption of the MHV does not decisively affect liver regeneration of remnant liver after right hemihepatectomy for hepatic tumors.

Portal vein ligation is as effective as sequential portal vein and hepatic artery ligation in inducing contralateral liver hypertrophy in a rat model

PURPOSE

Dual embolization of the hepatic artery and portal vein (PV) has been proposed to enhance contralateral liver regeneration before resection. The aim of this study was to evaluate the effect of PV ligation compared with simultaneous or sequential dual ligation on regeneration, proinflammatory response, and liver damage.

MATERIALS AND METHODS

Single hepatic artery ligation (HAL), PV ligation (70%), or dual ligation of the hepatic artery and PV (70%) simultaneously or sequentially within a 48-hour interval was performed in a rat model. Liver regeneration, proinflammatory mediators, hepatocellular synthetic function and injury, histopathology, and apoptosis were assessed at a maximum of 14 days after surgery.

RESULTS

Sequential dual ligation resulted in a faster increase in hepatocyte proliferation at 24 hours without additional increase in liver mass compared with PV ligation after 14 days. Both dual ligations significantly increased proinflammatory response in plasma and in the regenerating liver compared with PV ligation alone. Fourteen days after PV ligation, the hepatic parenchyma was completely restored, whereas fibronecrosis was seen in the sequentially dual-ligated groups and complete necrosis was seen in simultaneously ligated groups. Increased apoptosis in the regenerating liver and prolonged hepatic dysfunction were observed after both dual ligations.

CONCLUSIONS

PV ligation is as effective as dual ligation in inducing liver regeneration. No additional benefit of arterial ligation was observed.

Geometric shifting of the porta hepatis during posthepatectomy radiotherapy for biliary tract cancer

PURPOSE

To evaluate geometric shifting of the porta hepatis induced by liver regeneration during radiotherapy (RT) after partial hepatectomy for biliary tract cancer.

METHODS AND MATERIALS

Between August 2004 and August 2005, the study enrolled 10 biliary tract cancer patients who underwent hemihepatectomy or more extensive surgery and were scheduled to receive postoperative RT. All patients received 4500 cGy RT in 25 fractions with concurrent 5-fluorouracil. Before RT and in the third and fifth weeks during RT, the liver volume was determined using CT, and geometric location of the porta hepatis was determined using a conventional simulator.

RESULTS

The liver volume increase during RT was 246.6 +/- 118.2 cm(3). The overall actual shifting length of the porta hepatis was 9.8 +/- 2.5 mm, with right and left hepatectomy causing a 10.1 +/- 1.7 mm shift to the right or 9.2 +/- 4.3 mm shift to the left, respectively. The actual shifting length of the porta hepatis was proportional to the increase in liver volume during RT (r = 0.742, p = 0.014).

CONCLUSION

The results of this study have demonstrated that the porta hepatis can be shifted by liver regeneration after partial hepatectomy. We recommend an additional RT margin or adaptive RT (repeat planning at several intervals during the treatment course) to avoid exclusion of the porta hepatis from the RT target volume after partial hepatectomy for biliary tract cancer.

Regeneration and function of hemiliver graft: right versus left

BACKGROUND

A right liver graft used almost routinely for adult living donor liver transplantation (LDLT), is associated with a higher incidence of morbidity and mortality in the donor. We compared volume regeneration and graft function between left and right liver grafts to examine the feasibility of using left liver grafts.

METHODS

The left liver was considered acceptable as a graft when it was estimated to be over 40% of the recipient standard liver volume. Otherwise, right liver harvesting was used, provided the estimated right liver volume was less than 70% of the donor's standard liver volume. Graft volume on computed tomography and the results of liver function tests 1, 3, and 12 months after LDLT were compared between recipients with left (n = 76) and right (n = 83) grafts. Possible factors influencing graft regeneration were evaluated by multivariate analysis.

RESULTS

A higher regeneration rate in the left liver graft group resulted in the same ratio of graft to standard liver volume as in the right liver graft group (88% vs 87%) 1 year after LDLT. Liver function tests and 5-year survival rates were comparable between the 2 groups. An episode of acute rejection was a predictive factor for impaired graft regeneration 1 month after LDLT. The initial ratio of graft volume to standard liver volume was an independent factor for regeneration 1 year after LDLT.

CONCLUSIONS

A properly evaluated left liver graft can be used as safely as a right liver graft in adult-to-adult LDLT. The findings of the present study justify LDLT with a left liver graft under specific selection criteria and may be preferred to a right liver graft.

Serum lipid and lipoprotein alterations represent recovery of liver function after hepatectomy

BACKGROUND

The assessment of liver function during human liver regeneration is necessary to prevent unexpected liver failure and to prepare for further treatment. We selected patients prospectively and measured serum lipid and lipoprotein levels to identify which lipids and lipoproteins could represent recovery of liver function in human liver regeneration.

METHODS

Thirty selected patients who underwent hepatectomy were divided into three groups depending on the serum hyaluronate (HA) level and the type of liver resection.

RESULTS

We found three patterns of lipid and lipoprotein alterations after hepatectomy. Among the lipids and lipoproteins examined, the serum beta-lipoprotein and low-density lipoprotein (LDL) levels were significantly different among the groups at 7 days after hepatectomy. The alteration of the apolipoprotein (Apo) B level was similar to that of LDL. The LDL level was correlated with both beta-lipoprotein and Apo B before hepatectomy (r=0.653 and 0.894, respectively) and at 7 days after hepatectomy (r=0.841 and 0.943, respectively).

CONCLUSION

Serum HA before hepatectomy can reflect postoperative liver function depending on the type of liver resection. Recovery of the beta-lipoprotein and LDL levels can reflect the recovery of liver function in human liver regeneration within the early period in association with the Apo B level.