Preliminary study on liver function changes after trisectionectomy with versus without prior portal vein embolization

Perioperative LiMAx Test Analysis: Impact of Portal Vein Embolisation, Chemotherapy and Major Liver Resection

BACKGROUND

Postoperative liver failure (PLF) is a severe complication after major liver resection (MLR). To increase the safety of patients, clinical bedside tests are of great importance. However, limitations of their applicability and validity impair their value.

METHODS

Preoperative measurements of the liver maximum capacity (LiMAx) were performed in n = 40 patients, who underwent MLR (≥3 segments). Matched postoperative LiMAx was measured in n = 21 patients. Liver function was compared between pretreated patients (n = 11 with portal vein embolisation (PVE) and n = 19 patients with preoperative chemotherapy) and therapy naïve patients. The LiMAx values were compared with liver-specific blood parameters and volumetric analysis.

RESULTS

In total, n = 40 patients were enrolled in this study. The majority of patients (n = 33; 82.5%) had high preoperative LiMAx values (>315 µg/kg/h), while only seven patients (17.5%) had medium values (140-315 µg/kg/h), and none of the patients had low values (<140 µg/kg/h). A comparison of pretreated patients (with PVE and/or chemotherapy) and therapy naïve patients showed no significant difference in the preoperative LiMAx values (p > 0.05). The preoperative LiMAx values were significantly higher than the matched postoperative values on postoperative day 1 (p < 0.0001). A comparison between the expected and measured postoperative LiMAx showed a difference (≥10%) in 7 out of 13 patients (53.8%). After an initial postoperative decrease in the LiMAx, the patients without complications (n = 12) showed a continuous increase until 14 days after surgery. In the patients with postoperative complications, a decrease in the LiMAx was associated with a prolonged recovery.

CONCLUSIONS

For patients undergoing MLR within the 0.5% rule, which is the clinical gold standard, the LiMAx values do not offer any additional information. Additionally, the LiMAx may have reflected liver function, but it did not deliver additional information regarding postoperative liver recovery. The clinical use of LiMAx might be relevant in selected patients beyond the 0.5% rule.

Liver Venous Deprivation (LVD) Versus Portal Vein Embolization (PVE) Alone Prior to Extended Hepatectomy: A Matched Pair Analysis

BACKGROUND

To investigate whether liver venous deprivation (LVD) as simultaneous, portal vein (PVE) and right hepatic vein embolization offers advantages in terms of hypertrophy induction before extended hepatectomy in non-cirrhotic liver.

MATERIALS AND METHODS

Between June 2018 and August 2019, 20 patients were recruited for a prospective, non-randomized study to investigate the efficacy of LVD. After screening of 134 patients treated using PVE alone from January 2015 to August 2019, 14 directly matched pairs regarding tumor entity (cholangiocarcinoma, CC and colorectal carcinoma, CRC) and hypertrophy time (defined as time from embolization to follow-up imaging) were identified. In both treatment groups, the same experienced reader (> 5 years experience) performed imaging-based measurement of the volumes of liver segments of the future liver remnant (FLR) prior to embolization and after the standard clinical hypertrophy interval (~ 30 days), before surgery. Percentage growth of segments was calculated and compared.

RESULTS

After matched follow-up periods (mean of 30.5 days), there were no statistically significant differences in relative hypertrophy of FLRs. Mean ± standard deviation relative hypertrophy rates for LVD/PVE were 59 ± 29.6%/54.1 ± 27.6% (p = 0.637) for segments II + III and 48.2 ± 22.2%/44.9 ± 28.9% (p = 0.719) for segments II-IV, respectively.

CONCLUSIONS

LVD had no significant advantages over the standard method (PVE alone) in terms of hypertrophy induction of the FLR before extended hepatectomy in this study population.

Volume-Function Analysis (LiMAx Test) in Patients with HCC and Cirrhosis Undergoing TACE-A Feasibility Study

BACKGROUND

Transarterial chemoembolization (TACE) is an important therapy for hepatocellular carcinoma (HCC) in cirrhosis. In particular in advanced cirrhosis, post-TACE hepatic failure liver (PTHF) failure may develop. Currently, there is no standardization for the periinterventional risk assessment. The liver maximum capacity (LiMAx) test assesses the functional liver capacity, but has not been investigated in this setting.

AIMS

The aim of this study was to prospectively evaluate periinterventional LiMAx and CT volumetry measurements in patients with cirrhosis and HCC undergoing repetitive TACE.

METHODS

From 06/2016 to 11/2017, eleven patients with HCC and cirrhosis undergoing TACE were included. LiMAx measurements (n = 42) were conducted before and after each TACE. Laboratory parameters were correlated with the volume-function data.

RESULTS

The median LiMAx levels before (276 ± 166 µg/kg/h) were slightly reduced after TACE (251 ± 122 µg/kg/h; p = 0.08). This corresponded to a median drop of 7.1%. Notably, there was a significant correlation between LiMAx levels before TACE and bilirubin (but not albumin nor albumin-bilirubin [ALBI] score) increase after TACE (p = 0.02, k = 0.56). Furthermore, a significantly higher increase in bilirubin in patients with LiMAx ≤ 150 µg/kg/h was observed (p = 0.011). LiMAx levels at different time points in single patients were similar (p = 0.2).

CONCLUSION

In our prospective pilot study in patients with HCC and cirrhosis undergoing multiple TACE, robust and reliable LiMAx measurements were demonstrated. Lower LiMAx levels before TACE were associated with surrogate markers (bilirubin) of liver failure after TACE. Specific subgroups at high risk of PTHF should be investigated. This might facilitate the future development of strategies to prevent occurrence of PTHF.

Hepatic function assessment to predict post-hepatectomy liver failure: what can we trust? A systematic review

Post hepatectomy liver failure (PHLF) could occur even though an adequate liver volume is preserved. Liver function is not strictly related to the volume and the necessity to pre-operatively predict the future liver remnant (FLR) function is emerging, together with the wide spreading of techniques, aiming to optimize the FLR. The aim of this study was to systematically review all the available tests, to pre-operatively assess the liver function and to estimate the risk of PHLF. A systematic literature research of Medline, Embase, Scopus was performed in accordance to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines, to identify all the studies available for pre-operative liver function tests to assess the risk of PHLF and/or complications. From the 1122 references retrieved, 79 were included in the review. Dynamic functional tests, such as indocyanine green test (ICG), could evaluate only global liver function, with no definition of functional capacity of the remnant. Magnetic resonance imaging (MRI) with liver-specific contrast agents enables both liver function and volume evaluation; the absence of ionizing radiation showed a better patient's compliance. Nuclear imaging studies as hepatobiliary scintigraphy (HBS) present the unique ability to allow a precise evaluation of the segmental liver function of the remnant liver. Liver volume could overestimate liver function. Several liver function tests are available to evaluate the risk of PHLF in the pre-operative setting. However, no single test alone could accurately predict PHLF. Pre-operative combination between a dynamic quantitative test, such as ICG, with MRI or HBS, should enable a more complete functional evaluation. Functional tests to predict PHLF should be chosen according to patient's characteristics, disease, and center experience.

Improving the Safety of Major Resection for Hepatobiliary Malignancy: Portal Vein Embolization and Recent Innovations in Liver Regeneration Strategies

PURPOSE OF REVIEW

For three decades, portal vein embolization (PVE) has been the "gold-standard" strategy to hypertrophy the anticipated future liver remnant (FLR) in advance of major hepatectomy. During this time, CT volumetry was the most common method to preoperatively assess FLR quality and function and used to determine which patients are appropriate surgical candidates. This review provides the most up-to-date methods for preoperatively assessing the anticipated FLR and summarizes data from the currently available strategies used to induce FLR hypertrophy before surgery for hepatobiliary malignancy.

RECENT FINDINGS

Functional and physiological imaging is increasingly replacing standard CT volumetry as the method of choice for preoperative FLR assessment. PVE, associating liver partition and portal vein ligation, radiation lobectomy, and liver venous deprivation are all currently available techniques to hypertrophy the FLR. Each strategy has pros and cons based on tumor type, extent of resection, presence or absence of underlying liver disease, age, performance status, complication rates, and other factors. Numerous strategies can lead to FLR hypertrophy and improve the safety of major hepatectomy. Which is best has yet to be determined.

Hepatic CYP1A2 activity in liver tumors and the implications for preoperative volume-function analysis

Dynamic liver function assessment by the [¹³C]methacetin maximal liver function capacity (LiMAx) test reflects the overall hepatic cytochrome P-450 (CYP) 1A2 activity. One proven strategy for preoperative risk assessment in liver surgery includes the combined assessment of the dynamic liver function by the LiMAx test, the volumetric analysis of the liver, and calculation of future liver remnant function. This so-called volume-function analysis assumes that the remaining CYP1A2 activity in any tumor lesion is zero. The here presented study aims to assess the remaining CYP1A2 activities in different hepatic tumor lesions and its consequences for the preoperative volume-function analysis in patients undergoing liver surgery. The CYP1A2 activity analysis of neoplastic lesions and adjacent nontumor liver tissue from resected tumor specimens revealed a significantly higher CYP1A2 activity (median, interquartile range) in nontumor tissues (35.5, 15.9-54.4 µU/mg) compared with hepatocellular adenomas (7.35, 1.2-32.5 µU/mg), hepatocellular carcinomas (0.18, 0.0-2.0 µU/mg), or colorectal liver metastasis (0.17, 0.0-2.1 µU/mg). In nontumor liver tissue, a gradual decline in CYP1A2 activity with exacerbating fibrosis was observed. The CYP1A2 activity differences were also reflected in CYP1A2 protein signals in the assessed hepatic tissues. Volume-function analysis showed a minimal deviation compared with the current standard calculation for hepatocellular carcinomas or colorectal liver metastasis (<1% difference), whereas a difference of 11.9% was observed for hepatocellular adenomas. These findings are important for a refined preoperative volume-function analysis and improved surgical risk assessment in hepatocellular adenoma cases with low LiMAx values. NEW & NOTEWORTHY The cytochrome P-450 (CYP) 1A2-dependent maximal liver function capacity test reflects the overall functional capacity of the liver. To which extent hepatocellular tumors harbor CYP1A2 activity and thus contribute to the maximal liver function capacity test outcome is unknown. We here show that hepatocellular adenomas but not hepatocellular carcinomas or colorectal liver metastasis contain significant residual CYP1A2 activity. These findings are important for an improved preoperative volume-function analysis and an accurate surgical risk assessment in hepatocellular adenoma cases.

Randomized clinical trial comparing liver resection with and without perioperative assessment of liver function

Background

Liver function tests may help to predict outcomes after liver surgery. The aim of this study was to evaluate the clinical impact on postoperative outcome and patient management of perioperative liver function testing using the LiMAx^® test.

Methods

A multicentre RCT was conducted in six academic liver centres. Patients with intrahepatic tumours scheduled for open liver resection of at least one segment were eligible. Patients were randomized to undergo additional perioperative liver function tests (LiMAx^® group) or standard care (control group). Patients in the intervention arm received two perioperative LiMAx^® tests, one before the operation for surgical planning and another after surgery for postoperative management. The primary endpoint was the proportion of patients transferred directly to a general ward. Secondary endpoints were severe complications, length of hospital stay (LOS) and length of intermediate care/ICU (LOI) stay.

Results

Some 148 patients were randomized. Thirty‐six of 58 patients (62 per cent) in the LiMAx^® group were transferred directly to a general ward, compared with one of 60 (2 per cent) in the control group (P < 0·001). The rate of severe complications was significantly lower in the LiMAx^® group (14 per cent versus 28 per cent in the control group; P = 0·022). LOS and LOI were significantly shorter in the LiMAx^® group (LOS: 10·6 versus 13·3 days respectively, P = 0·012; LOI: 0·8 versus 3·0 days, P < 0·001).

Conclusion

Perioperative use of the LiMAx^® test improves postoperative management and reduces the incidence of severe complications after liver surgery. Registration number: NCT01785082 ( https://clinicaltrials.gov).

The Predictive Value of the Maximal Liver Function Capacity Test for the Isolation of Primary Human Hepatocytes

The need for primary human hepatocytes is constantly growing for basic research, as well as for therapeutic applications. However, the isolation outcome strongly depends on the quality of liver tissue, and we are still lacking a preoperative test that allows the prediction of the hepatocyte isolation outcome. In this study, we evaluated the "maximal liver function capacity test" (LiMAx) as predictive test for the quantitative and qualitative outcome of hepatocyte isolation. This test is already used in clinical routine to measure preoperative and to predict postoperative liver function. The patient's preoperative mean LiMAx was obtained from the patient records, and preoperative computed tomography and magnetic resonance images were used to calculate the whole liver volume to adjust the mean LiMAx. The outcome parameters of the hepatocyte isolation procedures were analyzed in correlation with the adjusted mean LiMAx. Primary human hepatocytes were isolated from partial hepatectomies (n = 64). From these 64 hepatectomies we included 48 to our study and correlated their isolation outcome parameters with volume corrected LiMAx values. From a total of 11 hepatocyte isolation procedures, metabolic parameters (albumin, urea, and aspartate aminotransferase or AST) were assessed during the hepatocyte cultivation period of 5 days. The volume adjusted mean LiMAx showed a significant positive correlation with the total cell yield (p = 0.049; r = 0.242; n = 48). The correlations of volume adjusted LiMAx values with viable cell yield and cell viability did not reach statistical significance. To create a more homogenous study group regarding tumor entities, subgroup analyses were performed. A subgroup analysis of isolations from patients with colorectal metastasis revealed a significant correlation between volume adjusted mean LiMAx and total cell yield (p = 0.012; r = 0.488; n = 21) and viable cell yield (p = 0.034; r = 0.405; n = 21), whereas a subgroup analysis of isolations of patients with carcinoma of the biliary tree showed significant correlations of volume adjusted mean LiMAx with cell viability (r = 0.387; p = 0.046; n = 20) and lacked significant correlations with total cell yield (r = -0.060; p = 0.401; n = 20) and viable cell yield (r = 0.012; p = 0.480; n = 20). The volume-adjusted mean LiMAx did not show a significant correlation with any of the metabolic parameters. In conclusion, the LiMAx test might be a useful tool to predict the quantitative outcome of hepatocyte isolation, as long as underlying liver disease is taken into consideration.

ICG Clearance Test and 99mTc-GSA SPECT/CT Fusion Images

Preoperative estimation of future remnant liver function is critical for major hepatic surgery to avoid postoperative morbidity and mortality. Among several liver function tests, the indocyanine green (ICG) clearance test is still the most popular dynamic method. The usefulness of ICG clearance test parameters, such as ICGR15, KICG, or PDRICG, has been reported by many investigators. The transcutaneous non-invasive pulse dye densitometry system has made the ICG clearance test more convenient and attractive, even in Western countries. The concept of future remnant KICG (rem KICG), which combines the functional aspect and the volumetric factor of the future remnant liver, seems ideal for determining the maximum extent of major hepatic resection that will not cause postoperative liver failure. For damaged livers with functional heterogeneity among the hepatic segments, fusion images combining technetium-99m-diethylenetriaminepentaacetic acid-galactosyl human serum albumin single photon emission computed tomography (99mTc-GSA SPECT) and X-ray CT are helpful to precisely estimate the functional reserve of the future remnant liver. Another technique for image-based liver function estimation, gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid(Gd-EOB)-enhanced magnetic resonance imaging, may be an ideal candidate for the preoperative determination of future remnant liver function. Using these methods effectively, morbidity and mortality after major hepatic resection could be reduced.

Current Modalities for the Assessment of Future Remnant Liver Function

While imaging studies such as computed tomography or magnetic resonance imaging allow the volumetric assessment of the liver segments, only indirect information is provided concerning the quality of the liver parenchyma and its actual functional capacity. Assessment of liver function is therefore crucial in the preoperative workup of patients who require extensive liver resection and in whom portal vein embolization is considered. This review deals with the modalities currently available for the measurement of liver function. Passive liver function tests include biochemical parameters and clinical grading systems such as the Child-Pugh and MELD scores. Dynamic quantitative tests of liver function can be based on clearance capacity tests such as the indocyanine green (ICG) clearance test. Although widely used, discrepancies have been reported for the ICG clearance test in relation with clinical outcome. Nuclear imaging studies have the advantage of providing simultaneous morphologic (visual) and physiologic (quantitative functional) information about the liver. In addition, regional (segmental) differentiation allows specific functional assessment of the future remnant liver. Technetium-99m (^99mTc)-galactosyl human serum albumin scintigraphy and ^99mTc-mebrofenin hepatobiliary scintigraphy potentially identify patients at risk for post-resectional liver failure who might benefit from liver-augmenting techniques. As there is no one test that can measure all the components of liver function, liver functional reserve is estimated based on a combination of clinical parameters and quantitative liver function tests.

Functional considerations in ALPPS - consequences for clinical management

BACKGROUND

Since perioperative morbidity and mortality in ALPPS are extraordinarily high, a deeper understanding of actual liver function during the procedure is essential to make the approach safer.

METHODS

Data from 17 patients who underwent ALLPS were analyzed regarding their course of liver function capacity assessed with the LiMAx test and compared to an equal-sized matched cohort of patients that underwent PVE.

RESULTS

A comparison of LiMAx prior to and following ALPPS Step I (330 [258-385] vs. 197 [144-224] μg/kg/h, p = 0.003) and prior to and following PVE (386 [330-519] vs. 378 [336-455] μg/kg/h, p = 0.534) demonstrated a significant drop in function after ALLPS. A volume/function analysis predicting FLR function regarding step II revealed an excellent correlation of predicted versus assessed postoperative liver function with a mean relative difference of 9 (-6 to 18)% and an ICC of 0.905 (123 [74-138] vs. 107 [77-175] μg/kg/h, p = 0.310).

CONCLUSIONS

We provide evidence that liver function capacity is significantly impaired due to ALPPS step I. This is particularly notable when compared to PVE. Our data also shows that the portal ligated liver lobe still continues to contribute significantly to overall liver function. Therefore, FLR function after step II is still predictable by volume/function analysis.

Monitoring of liver function in a 73-year old patient undergoing 'Associating Liver Partition and Portal vein ligation for Staged hepatectomy': case report applying the novel liver maximum function capacity test

BACKGROUND

The two-stage liver resection combining in situ liver transection with portal vein ligation, also referred to as ALPPS (Associating Liver Partition and Portal vein ligation for Staged hepatectomy), has been described as a promising method to increase the resectability of liver tumors. However, one of the most important issues regarding the safety of this procedure is the optimal timing of the second stage at the point of sufficient hypertrophy of the future liver remnant. The recently developed liver maximum function capacity test (LiMAx) can be applied to monitor the liver function postoperatively and hence could be a useful tool for decision-making regarding the timing of the second stage of ALPPS.

CASE PRESENTATION

A 73-year-old female patient presented with metachronous colorectal liver metastasis comprising the complete right liver lobe as well as segment IV. Due to an insufficient future liver remnant (19.3 %; segments II and III of the liver) and a low future liver remnant:body weight ratio (0.28 %) the decision was made to perform an ALPPS-procedure in order to avoid development of postoperative small-for-size syndrome. Despite a formally sufficient increase of the FLR to 30.8 % within 7 days after the first step of ALPPS, the liver function was seen to only slowly increase as expressed by a LiMAx value of 245 μg/h/kg (baseline of 282 μg/h/kg prior to surgery). By means of the LiMAx test, sufficient increase of liver function eventually was detected by postoperative day 11 (LiMAx value of 371 μg/h/kg; FLR 35.2 %) so that the second step of ALPPS (completion of hepatectomy) was performed with no signs of liver failure during further clinical course.

CONCLUSION

Performing ALPPS we have observed a significant difference between the increase in future liver remnant volume and function applying the LiMAx test. The latter tool thus might proof valuable for application in two-stage liver resection to avoid postoperative small-for-size syndrome.