Rapid liver volume increase induced by associating liver partition with portal vein ligation for staged hepatectomy (ALPPS): Is it edema, steatosis, or true proliferation?

Liver Histology Predicts Liver Regeneration and Outcome in ALPPS: Novel Findings From A Multicenter Study

BACKGROUND AND AIMS

Alterations in liver histology influence the liver's capacity to regenerate, but the relevance of each of the different changes in rapid liver growth induction is unknown. This study aimed to analyze the influence of the degree of histological alterations during the first and second stages on the ability of the liver to regenerate.

METHODS

This cohort study included data obtained from the International ALPPS Registry between November 2011 and October 2020. Only patients with colorectal liver metastases were included in the study. We developed a histological risk score based on histological changes (stages 1 and 2) and a tumor pathology score based on the histological factors associated with poor tumor prognosis.

RESULTS

In total, 395 patients were included. The time to reach stage 2 was shorter in patients with a low histological risk stage 1 (13 vs 17 days, P ˂0.01), low histological risk stage 2 (13 vs 15 days, P <0.01), and low pathological tumor risk (13 vs 15 days, P <0.01). Regarding interval stage, there was a higher inverse correlation in high histological risk stage 1 group compared to low histological risk 1 group in relation with future liver remnant body weight ( r =-0.1 and r =-0.08, respectively), and future liver remnant ( r =-0.15 and r =-0.06, respectively).

CONCLUSIONS

ALPPS is associated with increased histological alterations in the liver parenchyma. It seems that the more histological alterations present and the higher the number of poor prognostic factors in the tumor histology, the longer the time to reach the second stage.

Early Postoperative Serum Phosphate Drop Predicts Sufficient Hypertrophy After Liver Surgery

OBJECTIVE

The aim of this study was to assess the impact of postoperative hypophosphatemia on liver regeneration after major liver surgery in the scenario of Associating Liver Partition with Portal vein ligation for Staged hepatectomy (ALPPS) and living liver donation (LLD).

BACKGROUND

Hypophosphatemia has been described to reflect the metabolic demands of regenerating hepatocytes. Both ALPPS and LLD are characterized by an exceptionally strong liver regeneration and may be of particular interest in the context of posthepatectomy hypophosphatemia.

METHODS

Serum phosphate changes within the first 7 postoperative days after ALPPS (n=61) and LLD (n=54) were prospectively assessed and correlated with standardized volumetry after 1 week. In a translational approach, postoperative phosphate changes were investigated in mice and in vitro .

RESULTS

After ALPPS stage 1 and LLD, serum phosphate levels significantly dropped from a preoperative median of 1.08 mmol/L [interquartile range (IQR) 0.92-1.23] and 1.07 mmol/L (IQR 0.91-1.21) to a postoperative median nadir of 0.68 and 0.52 mmol/L, respectively. A pronounced phosphate drop correlated well with increased liver hypertrophy ( P <0.001). Patients with a low drop of phosphate showed a higher incidence of posthepatectomy liver failure after ALPPS (7% vs 31%, P =0.041). Like in humans, phosphate drop correlated significantly with degree of hypertrophy in murine ALPPS and hepatectomy models ( P <0.001). Blocking phosphate transporter (Slc20a1) inhibited cellular phosphate uptake and hepatocyte proliferation in vitro.

CONCLUSION

Phosphate drop after hepatectomy is a direct surrogate marker for liver hypertrophy. Perioperative implementation of serum phosphate analysis has the potential to detect patients with insufficient regenerative capacity at an early stage.

Minimizing the risk of small-for-size syndrome after liver surgery

BACKGROUND

Primary and secondary liver tumors are not always amenable to resection due to location and size. Inadequate future liver remnant (FLR) may prevent patients from having a curative resection or may result in increased postoperative morbidity and mortality from complications related to small-for-size syndrome (SFSS).

DATA SOURCES

This comprehensive review analyzed the principles, mechanism and risk factors associated with SFSS and presented current available options in the evaluation of FLR when planning liver surgery. In addition, it provided a detailed description of specific modalities that can be used before, during or after surgery, in order to optimize the conditions for a safe resection and minimize the risk of SFSS.

RESULTS

Several methods which aim to reduce tumor burden, preserve healthy liver parenchyma, induce hypertrophy of FLR or prevent postoperative complications help minimize the risk of SFSS.

CONCLUSIONS

With those techniques the indications of radical treatment for patients with liver tumors have significantly expanded. The successful outcome depends on appropriate patient selection, the individualization and modification of interventions and the right timing of surgery.

Pushing the limit of liver regeneration - Safety and survival after monosegment-ALPPS: systematic review and individual patient data meta-analysis

BACKGROUND

Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) has expanded and spearheaded development in hepatobiliary surgery. Monosegment-ALPPS tests liver regeneration limits and may present as the last feasible curative treatment option.

METHODS

Electronic databases (MEDLINE, Web of Science, Google Scholar, Cochrane Library and WHO International Clinical Trials Registry Platform) were searched for publications on mono-ALPPS using a predefined strategy without date or language restrictions. Individual patient data was extracted and analyzed.

RESULTS

237 publications were identified. 19 patients were identified to have undergone mono-ALPPS. Primarily, mono-ALPPS has been utilized as curative treatment for CRLM (17 of 19 cases). Successful mono-ALPPS was possible in FLR above 8% SLV. All patients received either chemotherapy alone or in combination with radiotherapy prior to surgery. 8 of 19 patients experienced PHLF grade A or B. There was no in-hospital mortality described. Recurrent disease has occurred in 7 of 19 patients and 3 have died during follow-up.

CONCLUSION

Mono-ALPPS is an experimental procedure that provides a reasonably safe opportunity to curatively treat extensive liver malignancies in patients with FLR as low as 8% SLV. PHLF is the most prevalent complication in mono-ALPPS. Mono-ALPPS should be evaluated in a multicentral study setting.

Left renal vein graft and in situ hepatic perfusion in hepatectomy for complete tumor invasion of hepatic veins: hemodynamic optimization and surgical technique

Purpose

Assessing hepatic vein reconstruction using a left renal vein graft and in situ hypothermic liver perfusion in an extended liver resection.

Methods

Patients included in this study were those with liver tumors undergoing curative surgery with resection and reconstruction of hepatic veins. Hepatic vein was reconstructed using a left renal vein graft. We describe the technical aspects of liver resection and vascular reconstruction, the key aspects of hemodynamic management, and the use of in situ hypothermic liver preservations during liver transection (prior to and during vascular clamping).

Results

The right hepatic vein was reconstructed with a median left renal venal graft length of 4.5 cm (IQR, 3.1–5.2). Creatinine levels remained within normal limits in the immediate postoperative phase and during follow-up. Median blood loss was 500 ml (IQR, 300–1500) and in situ perfusion with cold ischemia was 67 min (IQR, 60.5–77.5). The grafts remained patent during the follow-up with no signs of thrombosis. No major postoperative complications were observed.

Conclusion

Left renal vein graft for the reconstruction of a hepatic vein and in situ hypothermic liver perfusion are feasible during extended liver resection.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00423-022-02451-6.

The Role of Farnesoid X Receptor in Accelerated Liver Regeneration in Rats Subjected to ALPPS

Background: the role of bile acid (BA)-induced farnesoid X receptor (Fxr) signaling in liver regeneration following associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) was investigated in a rat model. Methods: Male Wistar rats underwent portal vein ligation (PVL) (n = 30) or ALPPS (n = 30). Animals were sacrificed pre-operatively and at 24, 48, 72, or 168 h after intervention. Regeneration rate, Ki67 index, hemodynamic changes in the hepatic circulation, and BA levels were assessed. Transcriptome analysis of molecular regulators involved in the Fxr signaling pathway, BA transport, and BA production was performed. Results: ALLPS induced more extensive liver regeneration (p < 0.001) and elevation of systemic and portal BA levels (p < 0.05) than PVL. The mRNA levels of proteins participating in hepatic Fxr signaling were comparable between the intervention groups. More profound activation of the intestinal Fxr pathway was observed 24 h after ALPPS compared to PVL. Conclusion: Our study elaborates on a possible linkage between BA-induced Fxr signaling and accelerated liver regeneration induced by ALPPS in rats. ALPPS could trigger liver regeneration via intestinal Fxr signaling cascades instead of hepatic Fxr signaling, thereby deviating from the mechanism of BA-mediated regeneration following one-stage hepatectomy.

FDG-PET/CT: novel method for viability assessment of livers perfused ex vivo

PURPOSE

Ex vivo liver machine perfusion is a promising option to rescue marginal liver grafts mitigating the donated organ shortage. Recently, a novel liver perfusion machine that can keep injured liver grafts alive for 1 week ex vivo was developed and reported in Nature Biotechnology. However, liver viability assessment ex vivo is an unsolved issue and the value of 18F-fluorodeoxyglucose (FDG)-PET/CT for such purpose was explored.

MATERIALS AND METHODS

Discarded two human and six porcine liver grafts underwent FDG-PET/CT for viability assessment after 1 week of ex vivo perfusion. PET parameters [standardized uptake value (SUV)max, SUVmean, SUVpeak and total lesion glycolysis] were compared between hepatic lobes and between porcine and human livers. The prevalence of FDG-negative organ parts was recorded. The estimated effective radiation dose for PET/CT was calculated.

RESULTS

All organs were viable with essentially homogeneous FDG uptake. Of note, viability was preserved in contact areas disclosing the absence of pressure necrosis. Four porcine and two human organs had small superficial FDG-negative areas confirmed as biopsy sites. Total lesion glycolysis was significantly higher in the right hepatic lobe (P = 0.012), while there was no significant difference of SUVmax, SUVmean and SUVpeak between hepatic lobes. There was no significant difference in FDG uptake parameters between porcine and human organs. The estimated effective radiation dose was 1.99 ± 1.67 mSv per organ.

CONCLUSION

This study demonstrates the feasibility of FDG-PET/CT for viability assessment of ex vivo perfused liver grafts after 1 week.

Rescue radiofrequency ablation or percutaneous ethanol injection: a strategy for failed RALPPS stage-1 in patients with cirrhosis-related hepatocellular carcinoma

Background

The future liver remnant (FLR) faces a risk of poor growth in patients with cirrhosis-related hepatocellular carcinoma (HCC) after stage-1 radiofrequency-assisted ALPPS (RALPPS). The present study presents a strategy to trigger further FLR growth using supplementary radiofrequency ablation (RFA) and percutaneous ethanol injection (PEI).

Methods

At RALPPS stage-1 the portal vein branch was ligated, followed by intraoperative RFA creating a coagulated avascular area between the FLR and the deportalized lobes. During the interstage period, patients not achieving sufficient liver size (≥ 40%) within 2–3 weeks underwent additional percutaneous RFA/PEI of the deportalized lobes (rescue RFA/PEI) in an attempt to further stimulate FLR growth.

Results

Seven patients underwent rescue RFA/PEI after RALPPS stage-1. In total five RFAs and eight PEIs were applied in these patients. The kinetic growth rate (KGR) was highest the first week after RALPPS stage-1 (10%, range − 1% to 15%), and then dropped to 1.5% (0–9%) in the second week (p < 0.05). With rescue RFA/PEI applied, KGR increased significantly to 4% (2–5%) compared with that before the rescue procedures (p < 0.05). Five patients proceeded to RALPPS stage-2. Two patients failed: In one patient the FLR remained at a constant level even after four rescue PEIs. The other patient developed metastasis. Except one patient died after RALPPS stage-2, no severe complications (Clavien-Dindo ≥ IIIb) occurred among remaining six patients.

Conclusions

Rescue RFA/PEI may provide an alternative to trigger further growth of the FLR in patients with cirrhosis-related HCC showing insufficient FLR after RALPPS stage-1.

Trial registration Retrospectively registered.

Bile formation in long-term ex situ perfused livers

BACKGROUND

Long-term ex situ liver perfusion may rescue injured grafts. Little is known about bile flow during long-term perfusion. We report the development of a bile stimulation protocol and motivate bile flow as a viability marker during long-term ex situ liver perfusion.

METHODS

Porcine and human livers were perfused with blood at close to physiologic conditions. Our perfusion protocol was established during phase 1 with porcine livers (n = 23). Taurocholic acid was applied to stimulate bile flow. The addition of piperacillin-tazobactam (tazobac) and methylprednisolone was modified from daily bolus to controlled continuous application. We adapted the protocol to human livers (n = 12) during phase 2. Taurocholic acid was replaced with medical grade ursodeoxycholic acid.

RESULTS

Phase 2: Despite administering taurocholic acid, bile flow declined from 29.3 ± 6.5 to 9.3 ± 1.4 mL/h (P < .001). Shortly after bolus of tazobac/methylprednisolone, bile flow recovered to 39.0 ± 9.7 mL/h with a decrease of solid bile components. This implied bile salt independent bile flow stimulation by tazobac/methylprednisolone. Phase 2: Ursodeoxycholic acid was shown to stimulate bile flow ex situ in human livers. Eight livers were perfused successfully for 1 week with continuous bile flow. The other 4 livers demonstrated progressive cell death, of which only 1 exhibited bile flow.

CONCLUSION

A lack of bile flow stimulation leads to a decline in bile flow and is not necessarily a sign of deterioration in liver function. Proper administration of stimulators can induce constant bile flow during ex situ liver perfusion for up to 1 week. Medical grade ursodeoxycholic acid is a suitable replacement for nonmedical grade taurocholic acid. The presence of bile flow alone is not sufficient to assess liver viability.

Hyperoxia in portal vein causes enhanced vasoconstriction in arterial vascular bed

Long-term perfusion of liver grafts outside of the body may enable repair of poor-quality livers that are currently declined for transplantation, mitigating the global shortage of donor livers. In current ex vivo liver perfusion protocols, hyperoxic blood (arterial blood) is commonly delivered in the portal vein (PV). We perfused porcine livers for one week and investigated the effect of and mechanisms behind hyperoxia in the PV on hepatic arterial resistance. Applying PV hyperoxia in porcine livers (n = 5, arterial PV group), we observed an increased need for vasodilator Nitroprussiat (285 ± 162 ml/week) to maintain the reference hepatic artery flow of 0.25 l/min during ex vivo perfusion. With physiologic oxygenation (venous blood) in the PV the need for vasodilator could be reduced to 41 ± 34 ml/week (p = 0.011; n = 5, venous PV group). This phenomenon has not been reported previously, owing to the fact that such experiments are not feasible practically in vivo. We investigated the mechanism of the variation in HA resistance in response to blood oxygen saturation with a focus on the release of vasoactive substances, such as Endothelin 1 (ET-1) and nitric oxide (NO), at the protein and mRNA levels. However, no difference was found between groups for ET-1 and NO release. We propose direct oxygen sensing of endothelial cells and/or increased NO break down rate with hyperoxia as possible explanations for enhanced HA resistance.

Integrative Concepts for Liver Surgery

BACKGROUND

Surgery is the standard treatment for primary tumors and metastases. Due to improvements in surgical outcomes as well as the efficacy of systemic treatments, the role of surgery has changed in recent years.

SUMMARY

Liver surgery has become safe and efficient, with resectability being increased by multimodality concepts as well as staged liver resections and orthotopic liver transplantation. These concepts may be applied to primary liver tumors but also to selected patients with liver metastases from various diseases. In addition, even debulking surgery may be indicated for selected patients with endocrine metastases. While patient selection for liver resections was limited to clinical parameters in the past, histological and molecular characteristics have become increasingly important. Moreover, the response to regional or systemic chemotherapy has been demonstrated to be strong for a beneficial course of the disease even in advanced diseases.

KEY-MESSAGES

Due to the variety of available treatment options, optimal patient selection is crucial. Besides liver surgery, staged concepts as well as liver transplantation are curative tools for many patients.

10th Anniversary of ALPPS-Lessons Learned and quo Vadis

OBJECTIVE

Associating Liver Partition and Portal vein ligation for Staged hepatectomy (ALPPS) has been tested in various indications and clinical scenarios, leading to steady improvements in safety. This report presents the current status of ALPPS.

SUMMARY BACKGROUND DATA

ALPPS offers improved resectability, but drawbacks are regularly pointed out regarding safety and oncologic benefits.

METHODS

During the 12th biennial congress of the European African-Hepato-Pancreato-Biliary Association (Mainz, Germany, May 23-26, 2017) an expert meeting "10th anniversary of ALPP" was held to discuss indications, management, mechanisms of regeneration, as well as pitfalls of this novel technique. The aim of the meeting was to make an inventory of what has been achieved and what remains unclear in ALPPS.

RESULTS

Precise knowledge of liver anatomy and its variations is paramount for success in ALPPS. Technical modifications, mainly less invasive approaches like partial, mini- or laparoscopic ALPPS, mostly aiming at minimizing the extensiveness of the first-stage procedure, are associated with improved safety. In fibrotic/cirrhotic livers the degree of future liver remnant hypertrophy after ALPPS appears some less than that in noncirrhotic. Recent data from the only prospective randomized controlled trial confirmed significant higher resection rates in ALPPS with similar peri-operative morbidity and mortality rates compared with conventional 2-stage hepatectomy including portal vein embolization. ALPPS is effective reliably even after failure of portal vein embolization.

CONCLUSIONS

Although ALPPS is now an established 2-stage hepatectomy additional data are warranted to further refine indication and technical aspects. Long-term oncological outcome results are needed to establish the place of ALPPS in patients with initially nonresectable liver tumors.

Minimally Invasive Approach in the Setting of ALPPS Procedure: a Systematic Review of the Literature

BACKGROUND

Associating liver partition with portal vein ligation for staged hepatectomy (ALPPS) represents a new surgical technique for the resection of advanced hepatic malignancies with predicted insufficient future liver remnant. In some patients, ALPPS can be associated with an increased risk of poor outcomes. Minimally invasive surgery (MIS) has been proposed in combination with ALPPS with the intent to minimize this risk. We systematically evaluated the outcomes of MIS-ALPPS cases to compare the relative outcomes of open ALPPS versus MIS-ALPPS.

METHODS

A systematic review was done in accordance with the PRISMA guidelines. Search terms utilized included the following: ("ALPPS"[Title/Abstract] OR "associating liver partition and portal vein ligation for staged hepatectomy"[Title/Abstract] OR "in situ split"[Title/Abstract]) AND ("minimally invasive"[Title/Abstract] OR "laparoscopic"[Title/Abstract] OR "robotic"[Title/Abstract]).

RESULTS

Fifteen articles were identified, with a total of 27 patients reported. Colorectal metastatic disease was the most commonly observed indication for MIS-ALPPS (66.7%), followed by hepatocellular carcinoma (25.9%). Time passed from the first to the second stage ranged 7-30 days. MIS-ALPPS patients did not experience procedure failures between the first and second stages. Only four (15.4%) subjects had a grade IIIb complication. No perioperative mortality after the first or second stage was reported. Compared with open ALPPS, MIS-ALPPS demonstrated better results. Hospital stay duration ranged 8-33 days with a follow-up ranging 1-20 months.

CONCLUSIONS

MIS-ALPPS appears to be safe, with potentially lower morbidities and mortalities relative to open patients. The present results should be considered with caution. A limited number of articles exist on this topic. Furthermore, selection biases exist when comparing open versus MIS-ALPPS data. Registry studies are needed to better define the outcomes of patients undergoing MIS-ALPPS.

A preliminary study of associating liver partition and portal vein ligation for staged hepatectomy in a rat model of liver cirrhosis

Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) in a rat model of liver cirrhosis has not, to the best of our knowledge, been previously investigated. The present study therefore aimed to establish a model of ALPPS in cirrhotic rats and to assess liver regeneration. Rats were randomly divided into an ALPPS group with carbon tetrachloride-induced cirrhosis (group A) and a normal liver (group B). Rat weight, cytokine levels, biochemical parameters and histopathology were assessed 1, 2, 3, 7 and 14 days after ALPPS. Higher aspartate aminotransferase and alanine aminotransferase levels were detected in group A on the first postoperative day. On the first, second and third days, hepatocyte proliferation rate was higher in group B than in group A. After 3 days, hepatocyte proliferation rate in group B began to decrease, but the rate in group A continued to increase until the 14th day. Higher levels of hepatocyte growth factor, interleukin-6 and tumor necrosis factor-α were detected in group A compared with group B, but the differences were not significant. The present study demonstrated that ALPPS promoted liver regeneration in a rat model of cirrhosis, but significantly impaired liver function. Compared with the ALPPS model, group B exhibited a delayed peak of proliferation. The mechanism of liver regeneration induced by ALPPS in cirrhotic rats may be associated with increased cytokine levels.

Preoperative Evaluation of Pancreatic Fibrosis and Lipomatosis: Correlation of Magnetic Resonance Findings With Histology Using Magnetization Transfer Imaging and Multigradient Echo Magnetic Resonance Imaging

OBJECTIVES

The purpose of this study was to evaluate the diagnostic performance of magnetization transfer (MT) imaging and multigradient echo magnetic resonance imaging (MRI) to quantify pancreatic fibrosis and lipomatosis in patients before pancreatoduodenectomy for postoperative risk stratification with histopathology as the reference standard.

MATERIALS AND METHODS

Twenty-four patients (age, 68 ± 8 years, 16 males) prospectively underwent quantitative MT imaging using a 2-dimensional gradient echo sequence with and without MT prepulse and multigradient echo imaging on a 3 T MRI 1 day before pancreatoduodenectomy due to adenocarcinoma of the pancreatic head region (n = 20), neuroendocrine tumor (n = 3), or intraductal papillary mucinous neoplasm (n = 1). Magnetization transfer ratio (MTR) and proton density fat fraction (PDFF) were measured in pancreatic tail (PT) and at the resection margin (RM). Histopathologically, pancreatic fibrosis was graded as mild, moderate, or severe (F1-F3), lipomatosis was graded as 0% to 10%, 11% to 30%, and greater than 30% fat deposition (L1-L3). In addition, MTR and histopathologic fibrosis was assessed in pancreatic adenocarcinoma. Mann-Whitney U test and Spearman correlation were used.

RESULTS

Patients with advanced pancreatic fibrosis (F3) showed a significantly higher MTR compared with the F1 group at the RM and PT (38 ± 4 vs 32.3 ± 1.6, P = 0.018 and 39.7 ± 5.5 vs 31.2 ± 1.7, P = 0.001). Spearman correlation coefficient of MTR and fibrosis grade was r = 0.532 (P = 0.011) and 0.554 (P = 0.008), respectively. Pancreatic parenchyma with advanced fat deposition (L2-L3) showed significantly higher PDFF compared with lipomatosis grade L1 (RM: P = 0.002 and PT: P = 0.001). Proton density fat fraction of pancreatic parenchyma exhibited a moderate and significant correlation with histopathologic lipomatosis grade (RM: r = 0.668 and PT: r = 0.707, P < 0.001). Magnetization transfer ratio was significantly higher in pancreatic adenocarcinoma compared with pancreatic parenchyma (44 ± 5.5 vs 36.0 ± 4.4 and 37.4 ± 5.4, P = 0.004).

CONCLUSIONS

Multiparametric MRI of the pancreas including MTR and PDFF maps may provide quantitative and noninvasive information on pancreatic fibrosis and lipomatosis before surgery.

Mitochondrial function after associating liver partition and portal vein ligation for staged hepatectomy in an experimental model

BACKGROUND

Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) is a two-stage strategy to induce rapid regeneration of the remnant liver. The technique has been associated with high mortality and morbidity rates. This study aimed to evaluate mitochondrial function, biogenesis and morphology during ALPPS-induced liver regeneration.

METHODS

Male Wistar rats (n = 100) underwent portal vein ligation (PVL) or ALPPS. The animals were killed at 0 h (without operation), and 24, 48, 72 or 168 h after intervention. Regeneration rate and proliferation index were assessed. Mitochondrial oxygen consumption and adenosine 5'-triphosphate (ATP) production were measured. Mitochondrial biogenesis was evaluated by protein level measurements of peroxisome proliferator-activated receptor γ co-activator (PGC) 1-α, nuclear respiratory factor (NRF) 1 and 2, and mitochondrial transcription factor α. Mitochondrial morphology was evaluated by electron microscopy.

RESULTS

Regeneration rate and Ki-67 index were significantly raised in the ALPPS group compared with the PVL group (regeneration rate at 168 h: mean(s.d.) 291·2(21·4) versus 245·1(13·8) per cent, P < 0·001; Ki-67 index at 24 h: 86·9(4·6) versus 66·2(4·9) per cent, P < 0·001). In the ALPPS group, mitochondrial function was impaired 48 h after the intervention compared with that in the PVL group (induced ATP production); (complex I: 361·9(72·3) versus 629·7(165·8) nmol per min per mg, P = 0·038; complex II: 517·5(48·8) versus 794·8(170·4) nmol per min per mg, P = 0·044). Markers of mitochondrial biogenesis were significantly lower 48 and 72 h after ALPPS compared with PVL (PGC1-α at 48 h: 0·61-fold decrease, P = 0·045; NRF1 at 48 h: 0·48-fold decrease, P = 0·028). Mitochondrial size decreased significantly after ALPPS (0·26(0·05) versus 0·40(0·07) μm² ; P = 0·034).

CONCLUSION

Impaired mitochondrial function and biogenesis, along with the rapid energy-demanding cell proliferation, may cause hepatocyte dysfunction after ALPPS. Surgical relevance Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) is a well known surgical strategy that combines liver partition and portal vein ligation. This method induces immense regeneration in the future liver remnant. The rapid volume increase is of benefit for resectability, but the mortality and morbidity rates of ALPPS are strikingly high. Moreover, lagging functional recovery of the remnant liver has been reported recently. In this translational study, ALPPS caused an overwhelming inflammatory response that interfered with the peroxisome proliferator-activated receptor γ co-activator 1-α-coordinated, stress-induced, mitochondrial biogenesis pathway. This resulted in the accumulation of immature and malfunctioning mitochondria in hepatocytes during the early phase of liver regeneration (bioenergetic destabilization). These findings might explain some of the high morbidity if confirmed in patients.

Hypertrophy and Liver Function in ALPPS: Correlation with Morbidity and Mortality

Background

ALPPS (associating liver partition and portal vein ligation for staged hepatectomy) was introduced with the promise to reduce posthepatectomy liver failure (PHLF) in extended hepatectomies but has higher morbidity and mortality rates compared to conventional methods of volume enhancement. There are few studies of the incidence of PHLF after ALPPS and little information on how to avoid PHLF by functional testing. It remains unclear what causes the compromise in liver function despite rapid volume gain and if any of the modifications proposed reduce the incidence of PHLF. This review summarizes published data on this topic.

Methods

This is a systematic review that studies literature on the incidence of liver failure and assessment of liver function following ALPPS as well as modifications of the existing technique. Articles were searched in PubMed, evaluated, selected, and tabulated.

Results

The literature search revealed 326 articles that met the selection criteria. PHLF criteria as defined by the International Study Group of Liver Surgery (ISGLS) were the most commonly used criteria, but PHLF was frequently not defined. PHLF occurred most frequently after stage 2 of ALPPS at around 30% in most larger studies. Hepatobiliary scintigraphy showed a discrepancy between volume and functional growth of the liver. Function increase was only 50% compared to volume increase. Mechanistic explanations using histologic analyses have been given to explain the immaturity of the liver after rapid hypertrophy. Modifications of ALPPS showed a comparable volumetric gain when compared to classic ALPPS, but data were lacking to assess PHLF.

Conclusion

ALPPS has relatively high rates of PHLF, morbidity, and mortality. This may be explained by data demonstrating functional growth when compared to volume growth. ALPPS should not be performed without functional assessment and with caution.