Standardized measurement of the future liver remnant prior to extended liver resection: methodology and clinical associations

Intrahepatic Cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC) arises from the epithelial cells of the intrahepatic and extrahepatic bile ducts and occurs proximal to the segmental biliary ducts. Risk factors include chronic hepatitis and cirrhosis, biliary inflammatory diseases, and hepatobiliary flukes, although in most cases, no known risk factor is identified. ICC is highly aggressive, with long-term survival only observed in patients with a complete R0 surgical resection. Technical and physiologic resectability should be considered when performing an operative plan. Nodal involvement is among the most important prognostic factors associated with survival and a porta hepatis lymphadenectomy should be performed at the time of resection. Adjuvant chemotherapy can provide a significant survival benefit for patients with more advanced or aggressive tumors. Systemic, locoregional, and targeted therapies exist for patients with unresectable or metastatic disease.

Clinical translation of liver regeneration therapies: A conceptual road map

The increasing incidence of severe liver diseases worldwide has resulted in a high demand for curative liver transplantation. Unfortunately, the need for transplants by far eclipses the availability of suitable grafts leaving many waitlisted patients to face liver failure and often death. Routine use of smaller grafts (for example left lobes, split livers) from living or deceased donors could increase the number of life-saving transplants but is often limited by the graft versus recipient weight ratio defining the safety margins that minimize the risk of small for size syndrome (SFSS). SFSS is a severe complication characterized by failure of a small liver graft to regenerate and occurs when a donor graft is insufficient to meet the metabolic demand of the recipient, leading to liver failure as a result of insufficient liver mass. SFSS is not limited to transplantation but can also occur in the setting of hepatic surgical resections, where life-saving large resections of tumors may be limited by concerns of post-surgical liver failure. There are, as yet no available pro-regenerative therapies to enable liver regrowth and thus prevent SFSS. However, there is optimism around targeting factors and pathways that have been identified as regulators of liver regeneration to induce regrowth in vivo and ex vivo for clinical use. In this commentary, we propose a roadmap for developing such pro-regenerative therapy and for bringing it into the clinic. We summarize the clinical indications, preclinical models, pro-regenerative pathways and safety considerations necessary for developing such a drug.

Associated liver partition and portal vein ligation for staged hepatectomy: a review

Outcomes of liver resection have improved with advances in surgical techniques, improvements in critical care and expansion of resectability criteria. However, morbidity and mortality following liver resection continue to plague surgeons. Post-hepatectomy liver failure (PHLF) due to inadequate future liver remnant (FLR) is an important cause of morbidity and mortality following liver resection. Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) is a novel two-staged procedure described in 2012, which aims to induce rapid hypertrophy of the FLR unlike conventional two-stage hepatectomy, which require a longer time for FLR hypertrophy. Careful patient selection and modifications in surgical technique has improved morbidity and mortality rates in ALPPS. Colorectal liver metastases (CRLM) confers the best outcomes post-ALPPS. Patients <60 years old and low-grade fibrosis with underlying hepatocellular carcinoma (HCC) are also eligible for ALPPS. Evidence for other types of cancers is less promising. Current studies, though limited, demonstrate that ALPPS has comparable oncological outcomes with conventional two-stage hepatectomy. Modifications such as partial-ALPPS and mini-ALPPS have shown improved morbidity and mortality compared to classic ALPPS. ALPPS may be superior to conventional two-stage hepatectomy in carefully selected groups of patients and has a promising outlook in liver surgery.

Hepatic metastasis from colorectal cancer

Colorectal cancer (CRC) is one of the most common cancers in the world. About two third of patients with CRC will develop distant recurrence at some point in time. Liver is the most common site where distant metastasis takes place. While the overall survival (OS) of patients with metastatic CRC was poor about 3 decades ago, there has been tremendous improvement in this area in the recent years. With the advent of effective systemic chemotherapy and biologic agents and better understanding of the biological behaviour of the tumour, aggressive treatment strategies such as metastatectomy of the liver metastases (or lung metastases) are now acceptable. More importantly, it has transformed the way how stage IV CRCs are being managed. From predominantly palliative as the primary aim, a comprehensive multidisciplinary approach is now the mainstay of treatment with very successful outcomes. Combination of systemic therapies with liver resection has been shown to be effective in providing promising survival benefits. In addition, other adjunctive modalities in targeting the liver metastases such as ablation, combining resection and ablation, transarterial chemoembolization, stereotactic body radiotherapy (SBRT), hepatic artery perfusion, etc. have also been demonstrated variable outcome in treating colorectal liver metastasis (CRLM). Very recently, transplant oncologists have also explored using liver transplantation as a treatment modality for unresectable CRLM, which has demonstrated very good long-term survival in well selected cases. The new paradigm in the treatment of metastatic CRC has dawned.

ALPPS for hepatocarcinoma under cirrhosis: a feasible alternative to portal vein embolization

Hepatocellular carcinoma (HCC) is one of the most common and malignant tumors. Preoperative portal vein embolization (PVE) is currently the most accepted treatment before major hepatic resection for HCC in patients with liver fibrosis or cirrhosis and associated insufficient future liver remnant (FLR). In the last decade, associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) technique has been described to obtain an increase of volume regarding PVE and a decrease of drop out. The initial excessive morbidity and mortality of this technique have decreased drastically due to a better selection of patients, the learning curve and the use of less aggressive variations of the original technique in the first stage. For both techniques a complete preoperative assessment of the FLR is the most important issue and only patients with and adequate FLR should be resected. ALPPS could be a feasible technique in very selected patients with HCC and cirrhosis. As long as it is performed in an experienced center could be used as a first choice technique versus PVE or could be used as a rescue technique in case of PVE failure.

Current role of trisectionectomy for hepatopancreatobiliary malignancies

BACKGROUND

Trisectionectomy is a treatment option in extensive liver malignancy, including colorectal liver metastases (CRLM). However, the reported experience of this procedure is limited. Therefore, we present our experience with right hepatic trisectionectomy (RHT) for CRLM as an example and discuss the changing role of trisectionectomy in the context of modern treatment alternatives based on a literature review.

METHODS

Between January 1993 and December 2014 all patients undergoing RHT at a single center in the UK for CRLM were included. Patient and tumor characteristics were reviewed and a multivariate analysis was done. Based on a literature review the role of trisectionectomy in the treatment of HPB malignancies was discussed.

RESULTS

A total of 211 patients undergoing RHT were included. Overall perioperative morbidity was 40.3%. Overall 90-day mortality was 7.6% but reduced to 2.8% over time. Multivariate analysis identified additional organ resection (P = .040) and blood transfusion (P = .028) as independent risk factors for morbidity. Multiple tumors, total hepatic vascular exclusion, and R1 resection were independent risk factors for significantly decreased disease-free and disease-specific survival. Further surgery for recurrence after RHT significantly prolonged survival compared with palliative chemotherapy only.

CONCLUSION

With the further development of surgical and multimodal treatment strategies in CRLM the indications for trisectionectomy are decreasing. Having being formerly associated with high rates of perioperative morbidity and mortality, this single-center experience clearly shows that these concomitant risks decrease with experience, liberal use of portal vein embolization and improved patient selection. Trisectionectomy remains relevant in selected patients.

Percutaneous radiofrequency-assisted liver partition versus portal vein embolization before hepatectomy for perihilar cholangiocarcinoma

Background

Percutaneous radiofrequency‐assisted liver partition with portal vein embolization in staged liver resection (PRALPPS) represents an alternative to portal vein embolization (PVE) followed by major liver resection in patients with perihilar cholangiocarcinoma.

Methods

This was an observational case–control study. Both procedures were applied in patients with a future liver remnant (FLR) volume of less than 40 per cent. The main end points of the study were short‐term morbidity and mortality for the two procedures. The study also compared the efficacy of the preresection phases estimated by kinetic growth rate (KGR), time interval and degree of hypertrophy of the FLR.

Results

The first phase (preresection) was completed in 11 and 18 patients, and the second phase (resection) in nine and 14 patients, in the PRALPPS and PVE groups respectively. Major morbidity after the first stage did not differ between the groups. There were no differences in blood loss, severe morbidity or liver failure rate after the second stage, with no deaths. The mean KGR of the FLR after the preresection phase for PRALPPS was 3·8 (0·6–9·8) per cent/day, and that after PVE was 1·8 (0–6·7) per cent/day (P = 0·037). The mean time interval for FLR hypertrophy in the PRALPPS and PVE groups was 15 (6–29) and 20 (8–35) days respectively (P = 0·039).

Conclusion

Short‐term outcomes were similar for PRALPPS and PVE in terms of safety. Remnant hypertrophy was achieved more rapidly by PRALPPS.

Portal Vein Embolization with PVA and Coils before Major Hepatectomy: Single-Center Retrospective Analysis in Sixty-Four Patients

Objectives

Portal vein embolization (PVE) stimulates hypertrophy of the future liver remnant (FLR) and improves the safety of extended hepatectomy. This study evaluated the efficacy of PVE, performed with PVA and coils, in relation to its effect on FLR volume and ratio. Secondary endpoints were the assessment of PVE complications, accomplishment of liver surgery, and patient outcome after hepatectomy.

Materials and Methods

All patients who underwent PVE before planned major hepatectomy between 2013 and 2017 were retrospectively analyzed, comprising a total of 64 patients. Baseline patient clinical characteristics, imaging records, liver volumetric changes, complications, and outcomes were analyzed.

Results

There were 45 men and 19 women with a mean age of 64 years. Colorectal liver metastasis was the most frequent liver tumor. The majority of patients (n = 53) had a right PVE. FLR increased from a mean value of 484 ml ± 242 to 654 ml ± 287 (p < 0.001) after PVE. Two major complications were experienced after PVE: 1 case of left hepatic artery branch laceration and 1 case of hemoperitoneum and hemothorax. A total of 44 (69%) patients underwent liver surgery. Twenty-one patients were not taken to surgery due to disease progression (n = 18), liver insufficiency (n = 1), and insufficient FLR volume (n = 1), and one patient declined surgery (n = 1).

Conclusions

PVE with PVA and coils was accomplished safely and promoted a high FLR hypertrophy yield, enabling most of our patients to be submitted to the potentially curative treatment of liver tumor resection.

Expanding the Surgical Pool for Hepatic Resection to Treat Biliary and Primary Liver Tumors

Surgical management of primary liver and biliary tract tumors has evolved over the past several decades, resulting in improved outcomes in these malignancies with historically poor prognoses. Expansion of patient selection criteria, progress in neoadjuvant and adjuvant therapies, development of techniques to increase future liver remnant, and the select utilization of liver transplantation have all contributed to increasing the patient pool for surgical intervention. Ongoing and future studies need to focus on improving multimodality treatment regimens and further refining the selection criteria for transplantation in order to optimize utilization of limited organ resources.

Interstage Assessment of Remnant Liver Function in ALPPS Using Hepatobiliary Scintigraphy: Prediction of Posthepatectomy Liver Failure and Introduction of the HIBA Index

OBJECTIVE

The aim of this study was to evaluate interstage liver function in associating liver partition and portal vein occlusion for staged hepatectomy (ALPPS) using hepatobiliary scintigraphy (HBS) and whether this may help to predict posthepatectomy liver failure (PHLF).

BACKGROUND

ALPPS remains controversial given the high rate of liver-related mortality after stage 2. HBS combined with single photon emission computed tomography (SPECT) accurately estimates future liver remnant function and may be useful to predict PHLF.

METHODS

Between 2011 and 2016, 20 of 39 patients (51.3%) underwent SPECT-HBS before ALPPS stage 2 for primary (n = 3) or secondary liver tumors (n = 17) at the Hospital Italiano de Buenos Aires (HIBA). PHLF was defined by the International Study Group of Liver Surgery criteria, 50-50 criteria, or peak bilirubin >7 mg/dL. Grade A PHLF was excluded, as it requires no change in clinical management. Receiver-operating characteristic curves were used to determine cutoff for HBS parameters.

RESULTS

Interstagely, 3 HBS parameters differed significantly between patients with (n = 4) and without PHLF (n = 16) after stage 2. Among these, the HIBA-index best predicted PHLF, with a cutoff value of 15%. The risk of PHLF in patients with cutoff <15% was 80%, whereas no patient with cutoff ≥15% developed PHLF.

CONCLUSIONS

Interstage HBS could help to predict clinically significant PHLF after ALPPS stage 2. An HIBA-index cutoff of 15% seemed to give the best diagnostic performance. Although further studies are needed to confirm our findings, the routine application of this noninvasive low-cost examination could facilitate decision-making in institutions performing ALPPS.

Outcomes of staged hepatectomies for liver malignancy

Liver malignancies are the fifth most common cause of death worldwide. Surgical intervention with curative intent is the treatment of choice for liver tumors as it provides long-term survival. However, only 20% of patients with metastatic liver lesions can be managed by curative liver resection. In most of the cases, hepatectomy is not feasible because of insufficient future liver remnant (FLR). Two-stage hepatectomy is advocated to achieve liver resection in a patient who is considered to not be a candidate for resection. Procedures of staged hepatectomy include conventional two-stage hepatectomy, portal vein embolization, and associating liver partition and portal vein ligation for a staged hepatectomy. Technical success is high for each of these procedures but variable between them. All the procedures have been reported as being effective in achieving a satisfactory FLR and completing the second-stage resection. Moreover, the overall survival and disease-free survival rates have improved significantly for patients who were otherwise considered nonresectable; yet, an increase in the morbidity and mortality rates has been observed. We suggest that this type of procedure should be carried out in high-flow centers and through a multidisciplinary approach. An experienced surgeon is key to the success of those interventions.

Resection of liver metastases from breast cancer: a multicentre analysis

BACKGROUND

Surgery is becoming more practical and effective than conservative treatment in improving the poor outcomes of patients with breast cancer liver metastasis (BCLM). However, there is no generally acknowledged set of standards for identifying BCLM candidates who will benefit from surgery.

METHODS

Between January 2011 and September 2018, 67 female BCLM patients who underwent partial hepatectomy were selected for analysis in the present study. Prognostic factors after hepatectomy were determined. Univariate and multivariate analyses were performed to identify predictors of overall survival (OS) and intrahepatic recurrence-free survival (IHRFS).

RESULTS

The 1-, 3- and 5-year OS of patients treated with surgery was 93.5%, 73.7% and 32.2%, respectively, with a median survival time of 57.59 months. The Pringle manoeuvre [hazard radio (HR) = 0.117, 95% CI0.015-0.942, p = 0.044] and an increased interval between breast surgery and BCLM diagnosis (HR0.178, 95% CI 0.037-0.869, p = 0.033) independently predicted improved overall survival for BCLM patients. The 1-, 2- and 3-year IHRFS of patients who underwent surgery was 62.8, 32.6% and 10.9%, respectively, with a median intrahepatic recurrence-free survival time of 13.47 months. Moderately differentiated tumours (HR  0.259, 95% CI 0.078-0.857, p = 0.027) and the development of liver metastasis more than 2 years after breast surgery (HR  0.270, 95% CI 0.108-0.675, p = 0.005) might be predictors of increased IHRFS.

CONCLUSIONS

An interval of more than 2 years between breast cancer surgery and liver metastasis seems to be an indication of liver surgery in BCLM patients. The Pringle manoeuvre and moderately differentiated tumours are potential predictors associated with OS and IHRFS, respectively, as benefits from liver resection. Studies with increased sample sizes are warranted to validate our results.

Transplantation versus liver resection in patients with hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common solid cancers in the world. Its treatment strategies have evolved significantly over the past few decades but the best treatment outcomes remain in the surgical arena. Especially for early HCCs, the options are abundant. However, surgical resection and liver transplantation provide the best long-term survival. In addition, there are evidence the ablative therapy such as radiofrequency ablation, could provide equivalent outcome as compared to resection. However, HCC is a unique malignancy as the majority of patients develop this cancer in the background of cirrhotic livers. As such, the treatment consideration should not only look at the oncological perspective but also the functional status of the liver parenchyma, i.e., the state of cirrhosis and presence of portal hypertension. Even with the most widely adopted staging systems for HCC such as the Barcelona Clinic Liver Cancer (BCLC) staging system and many other staging systems, none of them are ideal in including the various considerations for patients with HCCs. In this article, the key issues between choosing surgical resection and liver transplantation are discussed. A comprehensive review of the current surgical options are outlined in order to explore the pros and cons of each option.

Developing and validating a pre-operative risk score to predict post-hepatectomy liver failure

BACKGROUND

Post hepatectomy liver failure (PHLF) is a serious complication in patients undergoing liver resection. This study hypothesized that a new pre-operative risk score developed through statistical modeling to predict PHLF could be used to stratify patients at higher risk of PHLF.

METHODS

Patients who underwent hepatectomy between 2008 and 2016 were included in the derivation and validation cohorts. A multivariable binary logistic regression model was performed to identify predictors of PHLF, and a prognostic score was derived.

RESULTS

A total of 1269 patients were included in the derivation cohort. PHLF was encountered in 13.1% and was associated with significantly increased 90-day mortality and prolonged post-operative hospital stay (both p < 0.001). Multivariable analysis identified the extent of surgery (p < 0.001) and pre-operative bilirubin (p = 0.015), INR (p < 0.001), and creatinine (p = 0.048) to be independent predictors of PHLF. A risk score derived from these factors returned an area under the ROC curve (AUROC) of 0.816 (p < 0.001) for an internal validation cohort (N = 453), significantly outperforming the MELD score (AUROC: 0.643).

CONCLUSION

The PHLF risk score could be used to stratify the risk of PHLF among patients planned for hepatectomy.

Laparoscopic Parenchymal-Sparing Hepatectomy: the New Maximally Minimal Invasive Surgery of the Liver-a Systematic Review and Meta-Analysis

BACKGROUND

Parenchymal-sparing hepatectomies (PSH) are liver resections with preservation of as much liver parenchyma as possible. PSH can be performed laparoscopically (LPSH), but access to the posterosuperior segments is difficult and they are challenging when there are multiple bilobar lesions; the procedure may require repositioning and may be long and cumbersome. The objective of this systematic review is to analyze the feasibility and limitations of laparoscopic PSH in the literature.

METHODS

A systematic review of the literature was performed by searching Medline/PubMed, Scopus, and Cochrane databases. Resections were categorized by segment(s), and data regarding operative time, blood loss, length of hospital stay, complications, and R0 resection were analyzed.

RESULTS

Of 351 studies screened for relevance, 48 studies were reviewed. Ten publications fulfilled inclusion criteria, reporting data from 579 patients undergoing LPSH. The most common indication was CRLM (58%) followed by hepatocellular carcinoma (16%). Only 92 patients were reported to have resections of more than one tumor; the maximum number of lesions resected was seven. Of resected lesions, 21.5% were located in the cranial segments. Mean operating time was 335.2 min, estimated blood loss was 462 cc, and hospital stay was 7.6 days. Conversion rate was 9.7%, and complications occurred in 19.4% of cases. No perioperative mortality was reported. R0 resections were achieved in 87.7% of cases.

CONCLUSION

Laparoscopic PSH is performed and reported, but the data quality is low so far. The main limitation of LPSH is the low number of lesions resected, especially for bilobar, metastatic disease. Prospective reports with tumor-specific oncological data are desirable.

Long-term survival after post-hepatectomy liver failure for colorectal liver metastases

BACKGROUND

While post-hepatectomy liver failure (PHLF) accurately predicts short-term mortality, its role in prognosticating long-term overall survival (OS) remains unclear.

METHODS

Patients who underwent hepatectomy for colorectal liver metastases (CRLM) after portal vein embolization during 1999-2015 were evaluated retrospectively. PHLF was defined per International Study Group of Liver Surgery (ISGLS) criteria and as _PeakBil >7 mg/dl. Survival was analyzed using log-rank statistic and Cox regression; patient mortality within 90 days was excluded.

RESULTS

Of 175 patients, 68 (39%) had PHLF according to ISGLS criteria, including 40 (23%) with ISGLS grade B/C, and 14 (8%) had _PeakBil >7 mg/dl. Patients with _PeakBil >7 mg/dl had significantly worse OS than patients without PHLF (median OS, 16 vs 58 months, p = 0.001). Patients with ISGLS defined PHLF (p = 0.251) and patients with ISGLS grade B/C PHLF (p = 0.220) did not have worse OS than patients without PHLF.

CONCLUSION

Peak bilirubin >7 mg/dl impacts on long-term survival after hepatectomy for CRLM and is a better predictor of long-term survival than ISGLS-defined PHLF.

Dealing with an insufficient future liver remnant: Portal vein embolization and two-stage hepatectomy

Colorectal liver metastases (CLM) are not always resectable at the time of diagnosis. An insufficient future liver remnant is a factor excluding patients from curative intent resection. To deal with this issue, two-stage hepatectomy was introduced approximately 20 years ago. It is a sequential treatment strategy for bilateral CLM, which consists of preoperative chemotherapy, portal vein embolization, and planned first and second liver resections. This study reviews current evidence supporting use of two-stage hepatectomy.

Historical perspective: Two decades of progress in treating metastatic colorectal cancer

Colorectal cancer is the third most commonly diagnosed cancer in the United States. While screening methods strive to improve rates of early stage detection, 25% of patients have metastatic disease at the time of diagnosis, with the most common sites being the liver, lung, and peritoneum. While once perceived as hopeless, the last two decades have seen substantial strides in the medical, surgical, and regional therapies to treat metastatic disease offering significant improvements in survival.

Therapeutic implication of platelets in liver regeneration -hopes and hues

Mounting evidence highlights platelet involvement in liver regeneration via interaction with liver cells, growth factors release, and signaling contributions. Existing research suggests a compelling biological rationale for utilizing platelet biology, with the goal of improving liver function and accelerating its regenerative potential. Despite its expanding application in several clinical areas, the contribution of the platelet and its therapeutic implementation in liver regeneration so far has not yet fulfilled the initial high expectations. Areas covered: This review scrutinizes the progress, current updates, and discusses how recent understanding - particularly in the clinical implications of platelet-based therapy - may enable strategies to introduce and harness the therapeutic potential of the platelet during liver regeneration. Expert commentary: Several clinical and translational studies have facilitated a platform for the development of platelet-based therapy to enhance liver regeneration. While some of these therapies are effective to augment liver regeneration, the others have had some detrimental outcomes. The existing evidence represents a challenge for future projects that are focused on directly incorporating platelet-based therapies to induce liver regeneration.

Use of Computed Tomography Volumetry to Assess Liver Weight in Patients With Cirrhosis During Evaluation Before Living-Donor Liver Transplant

OBJECTIVES

Computed tomography liver volumetry has been widely used to detect total and segmental liver volume in living-donor liver transplantation. However, use of this technique to evaluate the cirrhotic liver remains unclear. In this study, we evaluated the accuracy of freehand computed tomography volumetry to assess total liver volume by comparing weights of total hepatectomy specimens in patients with cirrhosis. For our analyses, we considered the density of a cirrhotic liver to be 1.1 kg/L.

MATERIALS AND METHODS

Liver volume was measured using a freehand computed tomography technique in 52 patients with cirrhosis from different causes and who had no solid lesions before transplant. Measurements were made with a 16-slice multidetector computed tomography scanner (Siemens Somatom Sensation 16, Erlangen, Germany). For volumetric measurements, 10-mm-thick slices with 10-mm reconstruction intervals were preferred. Total hepatectomy weights of explant livers and computed tomography volumetry data were compared.

RESULTS

We excluded 3 cirrhotic patients with Budd-Chiari syndrome due to wide variations in scatterplot results. In the 49 patients included in the final analyses, average estimated liver volume by computed tomography was 721 ± 398 mL and actual cirrhotic liver weight was 727.8 ± 415 g. No significant differences were shown between these measurements. A simple regression analysis used to analyze correlations between estimated liver volume by computed tomography and real cirrhotic liver weight showed correlation of 0.957 (P < .001). When computed tomography liver volumetry as the independent variable and cirrhotic liver weight as dependent variable were considered, regression analyses showed R2 = 0.915.

CONCLUSIONS

Freehand computed tomography liver volumetry can be confidently used to evaluate liver volume in cirrhotic liver patients similar to use of this technique to estimate actual weights in normal livers. This technique can also be valuable during pretransplant and liver resection evaluations to ensure a more successful outcome.

Optimizing hepatectomy for hepatocellular carcinoma in Asia-patient selection and special considerations

Hepatocellular carcinoma (HCC) is a common affliction in Asia. The treatment of HCC depends on the tumor status as well as the underlying liver function. Resection is the cornerstone of surgical management of HCC. For those unfit to undergo resection, local ablative therapy is a viable alternative. For patients with multiple small unresectable HCCs, liver transplantation offers another option, having the simultaneous benefit of removing the cancer in addition to replacing the pre-malignant and cirrhotic liver together. However, the paucity of liver grafts limits the applicability of this operation. In assessing for the appropriate treatment, the traditional TNM staging is not widely applied to HCC. Conventionally, doctors in the West have relied on the Barcelona staging system. Asian surgeons, on the other hand, have long adopted a more aggressive approach for their patients. Borne out of the need for a system which better suited Asian patients, the Hong Kong guidelines have been established. For the surgical resection of HCC, considerations must take into account issues regarding the tumor, the underlying liver and the patient. For the tumor, the size, the presence vascular invasion and presence of extra-hepatic metastasis will determine operability. Another important issue is the liver function and, by extension, the estimated residual liver volume after resection. Thirdly, patient factors i.e., fitness to undergo general anesthesia must be properly assessed. With improved surgical technique and better patient selection, peri-operative morbidity and long-term survival results after operation have improved drastically over the past decades.

Conversion therapy and suitable timing for subsequent salvage surgery for initially unresectable hepatocellular carcinoma: What is new?

AIM

To review the conversion therapy for initially unresectable hepatocellular carcinoma (HCC) patients and the suitable timing for subsequent salvage surgery.

METHODS

A PubMed search was undertaken from 1987 to 2017 to identify articles using the keywords including “unresectable” “hepatocellular carcinoma”, ”hepatectomy”, ”conversion therapy”, “resection”, “salvage surgery” and “downstaging”. Additional studies were investigated through a manual search of the references from the articles. The exclusion criteria were duplicates, case reports, case series, videos, contents unrelated to the topic, comments, and editorial essays. The main and widely used conversion therapies and the suitable timing for subsequent salvage surgery were discussed in detail. Two members of our group independently performed the literature search and data extraction.

RESULTS

Liver volume measurements [future liver remnant (FLR)/total liver volume or residual liver volume/bodyweight ratio] and function tests (scoring systems and liver stiffness) were often performed in order to justify whether patients were suitable candidates for surgery. Successful conversion therapy was usually defined as downstaging the tumor, increasing FLR and providing subsequent salvage surgery, without increasing complications, morbidity or mortality. The requirements for performing salvage surgery after transcatheter arterial chemoembolization were the achievement of a partial remission in radiology, the disappearance of the portal vein thrombosis, and the lack of extrahepatic metastasis. Patients with a standardized FLR (sFLR) > 20% were good candidates for surgery after portal vein embolization, while other predictive parameters like growth rate, kinetic growth rate were treated as an effective supplementary. There was probably not enough evidence to provide a standard operation time after associating liver partition and portal vein ligation for staged hepatectomy or yttrium-90 microsphere radioembolization. The indications of any combinations of conversion therapies and the subsequent salvage surgery time still need to be carefully and comprehensively evaluated.

CONCLUSION

Conversion therapy is recommended for the treatment of initially unresectable HCC, and the suitable subsequent salvage surgery time should be reappraised and is closely related to its previous therapeutic effect.

Liver hypertrophy: Underlying mechanisms and promoting procedures before major hepatectomy

Various procedures can promote hypertrophy of the future liver remnant (FLR) before major hepatectomy to prevent postoperative liver failure. The pathophysiological situation following portal vein embolization (PVE), hepatic artery ligation/embolization or hepatectomy remains unclear. On one hand, the main mechanisms of hepatic regeneration appear to be driven by hepatic hypoxia (involving the hepatic arterial buffer response), an increased portal blood flow inducing shear stress and the involvement of several mediators (inflammatory cytokines, vasoregulators, growth factors, eicosanoids and several hormones). On the other hand, several factors are associated with impaired liver regeneration, such as biliary obstruction, malnutrition, diabetes mellitus, male gender, age, ethanol and viral infection. All these mechanisms may explain the varying degrees of hypertrophy observed following a surgical or radiological procedure promoting hypertrophy the FLR. Radiological procedures include left and right portal vein embolization (extended or not to segment 4), sequential PVE and hepatic vein embolization (HVE), and more recently combined PVE and HVE. Surgical procedures include associated liver partition and portal vein ligation for staged hepatectomy, and more recently the combined portal embolization and arterial ligation procedure. This review aimed to clarify the pathophysiology of liver regeneration; it also describes radiological or surgical procedures employed to improve liver regeneration in terms of volumetric changes, the feasibility of the second step and the benefits and drawbacks of each procedure.

The role of imaging in prediction of post-hepatectomy liver failure

Post-hepatectomy liver failure (PHLF) is not only a leading cause of mortality but also a leading cause of life-threatening complications in patients undergoing liver resection. The ability to accurately detect the emergence of PHLF represents a crucially important step. Currently, PHLF can be predicted by a comprehensive evaluation of biological, clinical, and anatomical parameters. With the development of new technologies, imaging methods including elastography, diffusion-weighted magnetic resonance imaging, and gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid-enhanced MRI play a more significant role in the pre-operative prediction and assessment of PHLF. In this review, we summarize the mainstream studies, with the aim of evaluating the role of imaging and improving the clinical value of existing scoring systems for predicting PHLF.

Reference values of liver volume in Caucasian population and factors influencing liver size

PURPOSE

To investigate factors influencing liver size and to determine reference values of liver volume (LV) for healthy subjects.

METHODS

2773 volunteers underwent magnetic resonance imaging (MRI) of the liver in the setting of the population based Study of Health in Pomerania. Based on measurement of maximum diameters in three orientations, LVs were calculated and correlated with demographic factors such as age, gender, and body mass index. In addition, LVs of healthy volunteers and participants with parenchymal liver diseases such as fatty liver disease, iron overload, fibrosis/cirrhosis were compared. Adjusted reference values of liver volumes were defined for the group of healthy participants.

RESULTS

In general, mean LV (mean ± standard deviation) was 1505 ± 385 cm³. Age, gender and body mass index correlated significantly with the liver volume (p ≤ 0.001). Parenchymal liver diseases significantly influence LV (with: 1624 ± 420 cm³, n = 1525 and without parenchymal liver diseases: 1360 ± 273 cm³; n = 1.248, p ≤ 0.001). Compared to LV of participants without liver diseases, LV was increased in volunteers with hepatic steatosis (1717 ± 419 cm³; n = 1111), liver iron overload (1558 ± 367 cm³; n = 553; p ≤ 0.001) as well as in participants with fibrosis/cirrhosis (1494 ± 459 cm³; n = 383).

CONCLUSIONS

LV is influenced by age, body mass index and parenchymal liver diseases. Reference values were established to aid in the diagnosis of parenchymal liver diseases.

Challenges of surgical management of intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma (iCCA) is a rare malignancy arising from biliary tract epithelium within bile ducts proximal to the secondary biliary radicles. The majority of patients are diagnosed with locally advanced or metastatic disease at presentation. Surgical resection remains the only potentially curative option, but poses unique challenges due to the large size and aggressive behavior of these tumors. Areas covered: The goal of surgical management of iCCA is margin negative (R0) hepatic resection with preservation of adequate size liver remnant and function. Data regarding role of staging laparoscopy, margin status, portal lymphadenectomy, and vascular resection for iCCA are reviewed. Perioperative systemic therapy may have value, although prospective data have been lacking. Recurrence rates remain high even after R0 resection; among patients with recurrent disease limited to the liver, re-resection or locoregional therapies may play a role. Liver transplantation may be an option for select patients with very early-stage iCCA, although this should be done on a protocol-only basis. Expert commentary: Appropriate preoperative patient selection and surgical technique are paramount to ensure optimal oncologic outcomes for patients with resectable iCCA. Improving systemic and locoregional therapy options may help decrease recurrence rates and improve long-term survival for this aggressive malignancy.

Surgical management of hilar cholangiocarcinoma at Memorial Sloan Kettering Cancer Center

Hilar cholangiocarcinoma, which represents approximately 60% of biliary tract malignancies, is increasing in incidence and presents an ongoing challenge for patients and hepatobiliary surgeons. Although the majority of patients present with advanced disease, the remaining minority of patients are best treated with surgical resection or transplant. Transplant is typically reserved for locally unresectable tumors often in the setting of underlying hepatic dysfunction and will not be discussed herein. This review, therefore, focuses on oncological resection and the strategies implemented for the treatment of hilar cholangiocarcinoma at a quaternary referral center, including preoperative considerations such as patient selection and optimization of the future liver remnant, nuances to the operative approach for these tumors such as resection under low central venous pressure and management of the bile duct, as well as postoperative management.

Indicating ALPPS for Colorectal Liver Metastases: A Critical Analysis of Patients in the International ALPPS Registry

OBJECTIVES

In the international associating liver partition and portal vein ligation for staged hepatectomy registry, more than 50% of patients underwent associating liver partition and portal vein ligation for staged hepatectomy with a right hepatectomy. This study evaluated the necessity of two-stage hepatectomies being performed as right hepatectomy associating liver partition and portal vein ligation for staged hepatectomy in patients with colorectal liver metastases versus right trisectionectomy associating liver partition and portal vein ligation for staged hepatectomy.

PATIENTS AND METHODS

All patients registered between 2012 and 2017 undergoing associating liver partition and portal vein ligation for staged hepatectomy for colorectal liver metastases were included. A liver to body weight index of 0.5 or less prior to stage I in the presence of liver damage was used as an internationally accepted standard to justify a two-stage hepatectomy.

RESULTS

Four-hundred and three patients with colorectal liver metastases with right hepatectomy associating liver partition and portal vein ligation for staged hepatectomy (n = 183) or right trisectionectomy associating liver partition and portal vein ligation for staged hepatectomy (n = 220) were analyzed. Presence of metastases in segments II/III, liver damage, number of patients on chemotherapy, and cycles were comparable, and there was a comparable response to chemotherapy. Liver to body weight index was different prior to stage 1 (right trisectionectomy associating liver partition and portal vein ligation for staged hepatectomy: 0.33 ± 0.12 versus right hepatectomy associating liver partition and portal vein ligation for staged hepatectomy: 0.40 ± 0,14; P < .001) and prior to stage 2 (right trisectionectomy associating liver partition and portal vein ligation for staged hepatectomy: 0.58 ± 0.17 versus right hepatectomy associating liver partition and portal vein ligation for staged hepatectomy: 0.66 ± 0,18; P < .001). Hypertrophy rates were similar between groups. As much as 16.9% and 7.2% of patients in right hepatectomy associating liver partition and portal vein ligation for staged hepatectomy and right trisectionectomy associating liver partition and portal vein ligation for staged hepatectomy had no apparent justification for a two-stage hepatectomy based on LBWI prior to stage 1 and absence of chemotherapy (<12 cycles).

CONCLUSION

More than 15% of associating liver partition and portal vein ligation for staged hepatectomy procedures were performed in patients who may have had no indication for a two-stage hepatectomy, especially in the group of patients with right hepatectomy. Thus, it appears that there is a risk of the overuse of associating liver partition and portal vein ligation for staged hepatectomy because of its great potential to induce volume growth. Due to the high perioperative risk of associating liver partition and portal vein ligation for staged hepatectomy, indications should be carefully reconsidered.

Serial Assessment of Growth Factors Associated with Liver Regeneration in Patients Operated with Associating Liver Partition and Portal Vein Ligation for Staged Hepatectomy

BACKGROUND

There is limited knowledge about the mechanisms behind the unparalleled growth of the future liver remnant (FLR) linked to associating liver partition and portal vein ligation for staged hepatectomy (ALPPS). In this study, liver regenerative markers were examined in patients subjected to ALPPS.

METHODS

Ten patients with colorectal liver metastases treated with neoadjuvant chemotherapy and ALPPS were included. Plasma was sampled at 6 time points and biopsies from both liver lobes were collected at both stages of ALPPS. The levels of interleukin (IL)-6, hepatocyte growth factor (HGF), tumor necrosis factor-α, epidermal growth factor, and vascular endothelial growth factor in plasma were measured at each time point. Expression of mRNA for markers of proliferation and apoptosis was studied in the biopsies from both liver lobes taken at both stages.

RESULTS

ALPPS resulted in a peak of IL-6 after stage 1 (p = 0.004), which decreased rapidly and did not increase again after stage 2. HGF also increased after stage 1 (p = 0.048), and the HGF levels correlated significantly with the degree of growth of the FLR before stage 2 (p = 0.02, r2 = 0.47). There was a correlation between peak levels of IL-6 and HGF (p = 0.03, r2 = 0.84).

CONCLUSIONS

IL-6 and HGF seem to be early mediators of hypertrophy after stage 1 in the ALPPS procedure. The peak HGF plasma level correlates with the degree of FLR growth in patients subjected to ALPPS.

Utility of 3D Reconstruction of 2D Liver Computed Tomography/Magnetic Resonance Images as a Surgical Planning Tool for Residents in Liver Resection Surgery

OBJECTIVE

A fundamental aspect of surgical planning in liver resections is the identification of key vessel tributaries to preserve healthy liver tissue while fully resecting the tumor(s). Current surgical planning relies primarily on the surgeon's ability to mentally reconstruct 2D computed tomography/magnetic resonance (CT/MR) images into 3D and plan resection margins. This creates significant cognitive load, especially for trainees, as it relies on image interpretation, anatomical and surgical knowledge, experience, and spatial sense. The purpose of this study is to determine if 3D reconstruction of preoperative CT/MR images will assist resident-level trainees in making appropriate operative plans for liver resection surgery.

DESIGN

Ten preoperative patient CT/MR images were selected. Images were case-matched, 5 to 2D planning and 5 to 3D planning. Images from the 3D group were segmented to create interactive digital models that the resident can manipulate to view the tumor(s) in relation to landmark hepatic structures. Residents were asked to evaluate the images and devise a surgical resection plan for each image. The resident alternated between 2D and 3D planning, in a randomly generated order. The primary outcome was the accuracy of resident's plan compared to expert opinion. Time to devise each surgical plan was the secondary outcome. Residents completed a prestudy and poststudy questionnaire regarding their experience with liver surgery and the 3D planning software.

SETTING AND PARTICIPANTS

Senior level surgical residents from the Queen's University General Surgery residency program were recruited to participate.

RESULTS

A total of 14 residents participated in the study. The median correct response rate was 2 of 5 (40%; range: 0-4) for the 2D group, and 3 of 5 (60%; range: 1-5) for the 3D group (p < 0.01). The average time to complete each plan was 156 ± 107 seconds for the 2D group, and 84 ± 73 seconds for the 3D group (p < 0.01). A total 13 of 14 residents found the 3D model easier to use than the 2D. Most residents noticed a difference between the 2 modalities and found that the 3D model improved their confidence with the surgical plan proposed.

CONCLUSIONS

The results of this study show that 3D reconstruction for liver surgery planning increases accuracy of resident surgical planning and decreases amount of time required. 3D reconstruction would be a useful model for improving trainee understanding of liver anatomy and surgical resection, and would serve as an adjunct to current 2D planning methods. This has the potential to be developed into a module for teaching liver surgery in a competency-based medical curriculum.

Measurement of Total Liver Volume Using the Energy Expenditure: A New Formula

BACKGROUND

The assessment of liver volume (LV) is important before surgical resection or transplantation to reduce the risk of hepatic insufficiency. LV is usually measured using computed tomography or with some formulas. The aim of this study was to develop a new dynamic formula to predict LV.

METHODS

Using computed tomography, LV was calculated in 101 patients without liver disease. LV was correlated with patient metabolic status, calculated with the Harris-Benedict equation for basal energy expenditure (BEE). Activity energy expenditure (AEE) was also calculated. Using linear regression analysis, a new formula was derived and was compared with Heinmann's, Urata's, Emre's, Vauthey's, Yoshizumi's, Yu's, and Hashimoto's formulas.

RESULTS

A new basal formula was established: LV = (0.789 × BEE) + 272. It was found to be the most accurate (R² = 0.39, p < 0.001). Heinmann's, Emre's, and Vauthey's formulas tend to overestimate LV, while Urata's, Yoshizumi's, Yu's, and Hashimoto's formulas tend to underestimate LV. A new AEE formula was also established: LV = (0.789 × AEE) + 272.

CONCLUSIONS

These formulas give a dynamic perspective of LV, which may be influenced by the patient's actual clinical status. Using these formulas, it is possible to estimate an increased value of LV, which may contribute to a reduction in the risk of postoperative hepatic insufficiency.

Increasing the remnant liver volume using portal vein embolization

Background: Portal vein embolization (PVE) is a common procedure to induce hypertrophy of the remnant liver (RL) before major hepatectomy. Objective: Evaluate increased RL volume after PVE based on CT volumetric measurement. Methods: Multi-detector computed tomography (MDCT) was used to measure hepatic volumetric measurement, including total liver volume and RL volumes of pre- and post-PVE. Complications were recorded from PVE and from three-month after post-extended hepatectomy liver dysfunction. Result and conclusion: There was a 10% increase in RL volume. Mean days between CT and PVE were 20 days. No major complications from PVE were observed.

Update on Liver Failure Following Hepatic Resection: Strategies for Prediction and Avoidance of Post-operative Liver Insufficiency

Liver resection is increasingly used for a variety of benign and malignant conditions. Despite advances in preoperative selection, surgical technique and perioperative management, posthepatectomy liver failure (PHLF) is still a leading cause of morbidity and mortality following liver resection. Given the devastating physiological consequences of PHLF and the lack of effective treatment options, identifying risk factors and preventative strategies for PHLF is paramount. In the past, a major limitation to conducting high quality research on risk factors and prevention strategies for PHLF has been the absence of a standardized definition. In this article, we describe relevant definitions for PHLF, discuss risk factors and prediction models, and review advances in liver assessment tools and PHLF prevention strategies.

Quantitative Imaging Features and Postoperative Hepatic Insufficiency: A Multi-Institutional Expanded Cohort

BACKGROUND

Post-hepatectomy liver insufficiency (PHLI) is a significant cause of morbidity and mortality after liver resection. Quantitative imaging analysis using CT scans measures variations in pixel intensity related to perfusion. A preliminary study demonstrated a correlation between quantitative imaging features of the future liver remnant (FLR) parenchyma from preoperative CT scans and PHLI. The objective of this study was to explore the potential application of quantitative imaging analysis in PHLI in an expanded, multi-institutional cohort.

STUDY DESIGN

We retrospectively identified patients from 5 high-volume academic centers who developed PHLI after major hepatectomy, and matched them to control patients without PHLI (by extent of resection, preoperative chemotherapy treatment, age [±5 years], and sex). Quantitative imaging features were extracted from the FLR in the preoperative CT scan, and the most discriminatory features were identified using conditional logistic regression. Percent remnant liver volume (RLV) was defined as follows: (FLR volume)/(total liver volume) × 100. Significant clinical and imaging features were combined in a multivariate analysis using conditional logistic regression.

RESULTS

From 2000 to 2015, 74 patients with PHLI and 74 matched controls were identified. The most common indications for surgery were colorectal liver metastases (53%), hepatocellular carcinoma (37%), and cholangiocarcinoma (9%). Two CT imaging features (FD1_4: image complexity; ACM1_10: spatial distribution of pixel intensity) were strongly associated with PHLI and remained associated with PHLI on multivariate analysis (p = 0.018 and p = 0.023, respectively), independent of clinical variables, including preoperative bilirubin and %RLV.

CONCLUSIONS

Quantitative imaging features are independently associated with PHLI and are a promising preoperative risk stratification tool.

Prediction of small for size syndrome after extended hepatectomy: Tissue characterization by relaxometry, diffusion weighted magnetic resonance imaging and magnetization transfer

This study aimed to monitor the course of liver regeneration by multiparametric magnetic-resonance imaging (MRI) after partial liver resection characterizing Small-for-Size Syndrome (SFSS), which frequently leads to fatal post-hepatectomy liver failure (PLF). Twenty-two C57BL/6 mice underwent either conventional 70% partial hepatectomy (cPH), extended 86% partial hepatectomy (ePH) or SHAM operation. Subsequent MRI scans on days 0, 1, 2, 3, 5 and 7 in a 4.7T MR Scanner quantified longitudinal and transverse relaxation times, apparent diffusion coefficient (ADC) and the magnetization-transfer ratio (MTR) of the regenerating liver parenchyma. Histological examination was performed by hematoxylin-eosin staining. After hepatectomy, an increase of T1 time was detected being larger for ePH on day 1: 18% for cPH vs. 40% for ePH and on day 2: 24% for cPH vs. 49% for ePH. An increase in T2 time, again greater in ePH was most pronounced on day 5: 21% for cPH vs. 41% for ePH. ADC and MTR showed a decrease on day 1: 21% for ePH vs. 13% for cPH for ADC, 15% for ePH vs. 11% for cPH for MTR. Subsequently, all MR parameters converged towards initial values in surviving animals. Dying PLF animals exhibited the strongest increase of T1 relaxation time and most prominent decreases of ADC and MTR. The retrieved MRI biomarkers indicate SFSS and potentially developing PLF at an early stage, likely reflecting cellular hypertrophy with extended water content and concomitantly diluted cellular components as features of liver regeneration, appearing more intense in ePH as compared to cPH.

Two-Stage Hepatectomy vs One-Stage Major Hepatectomy with Contralateral Resection or Ablation for Advanced Bilobar Colorectal Liver Metastases

BACKGROUND

Both 2-stage hepatectomy (TSH) and 1-stage hepatectomy (OSH) represent feasible strategies for resection of advanced bilobar colorectal liver metastases (CLM). However, the influence of the surgical approach on postoperative outcomes and overall survival (OS) is unknown. To define the optimal surgical approach for advanced bilobar CLM requiring right hemihepatectomy, we compared short-term and long-term outcomes after TSH and OSH with contralateral resection or radiofrequency ablation (RFA).

STUDY DESIGN

We retrospectively reviewed 227 patients with bilobar CLM, who underwent right or extended right hepatectomy with treatment of synchronous CLM in segments I, II, and/or III, between 1998 and 2015. Postoperative outcomes and OS were compared between patients who underwent TSH and those who underwent OSH.

RESULTS

Of the 227 patients, 126 (56%) underwent at least the first stage of TSH, and 101 (44%) underwent OSH, 29 (13%) without RFA and 72 (32%) with RFA. Two-stage hepatectomy was associated with a lower incidence of postoperative major complications (14% vs 26%, p = 0.03) and postoperative hepatic insufficiency (6% vs 20%, p = 0.001) than OSH. The 5-year OS rate was higher for patients assigned to TSH than for those who underwent OSH (35% vs 24%, p = 0.016). Patients who completed both stages of TSH had a higher 5-year OS rate than patients who underwent OSH without RFA (50% vs 20%, p = 0.023) or OSH with RFA (50% vs 24%, p < 0.0001).

CONCLUSIONS

In patients with advanced bilobar CLM, TSH is associated with fewer complications than OSH. Both TSH in intention-to-treat analysis and completed TSH in as-treated analysis were associated with better OS than OSH.

Did the International ALPPS Meeting 2015 Have an Impact on Daily Practice? The Hamburg Barmbek Experience of 58 Cases

Background

ALPPS (associating liver partition and portal vein ligation for staged hepatectomy) was introduced only 10 years ago and has gained wide acceptance as a variation of staged procedures in liver surgery. It has been criticized for its high morbidity and mortality, which all centers reported in their initial series.

Methods

After a world expert meeting in Hamburg in 2015 where all experts in the field met to discuss this method, caveats were extracted and formulated. We researched our complete prospective ALPPS database to see if the recommendations had any impact on outcome.

Results

In total, we performed 58 ALPPS procedures in our center. 33 patients were operated on before, 25 after the meeting. Results in terms of morbidity and mortality were significantly better after the meeting, as were patient selection and strategy.

Conclusion

In our own center's experience, the implementation of the meetings' recommendations and the information gathered through this valuable exchange had a dramatic impact on results. Having performed 58 ALPPS procedures in total, we can now conclude that ALPPS has become much safer in our hands since the 2015 meeting and that morbidity and mortality are no longer the issue to be discussed. Future research must focus on oncologic outcomes in these patients.

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.

Experimental evaluation of liver regeneration patterns and liver function following ALPPS

Background

The underlying mechanism of liver regeneration after Associating Liver Partition and Portal vein ligation (PVL) for Staged hepatectomy (ALPPS) is still unclear. The aim of this study was to evaluate the relationship between future liver remnant (FLR) volume, liver regeneration characteristics and restoration of function in an experimental model of ALPPS.

Methods

An ALPPS model in rats was developed with selective PVL, parenchymal transection and partial hepatectomy (step 1), followed by resection of the liver (step 2). Three different ALPPS groups with FLR sizes of 30, 20 and 10 per cent of total liver volume were compared with sham‐operated controls and animals undergoing resection of left lateral lobe and 90 per cent PVL with respect to morbidity, mortality, liver regeneration and function.

Results

Three of 15 animals that had ALPPS with 10 per cent FLR (ALPPS10) died after step 1. Ascites developed in two of five rats that had ALPPS with 20 per cent FLR and in three of four animals in the ALPPS10 group after step 2. Although the relative increments in FLR size and growth rates were highest in the ALPPS groups, small FLR size was associated with a sustained increase in levels of serum aminotransferases and bilirubin, a lower albumin concentration, severe sinusoidal injury, increased expression of proliferation markers and increased activation of hepatic progenitor cells after step 2.

Conclusion

There is discordance between FLR volume increase and functional restoration after the ALPPS procedure.

99mTc-mebrofenin hepatobiliary scintigraphy predicts liver failure following major liver resection for perihilar cholangiocarcinoma

BACKGROUND

Posthepatectomy liver failure (PHLF) is a threatening complication after liver surgery, especially in perihilar cholangiocarcinoma (PHC). This study aimed to assess the value of preoperative assessment of liver function using ^99mTc-mebrofenin hepatobiliary scintigraphy (HBS) to predict PHLF in comparison with liver volume in PHC patients.

METHODS

All patients who underwent resection of suspected PHC in a single center between 2000 and 2015 were included in the analysis. PHLF was graded according to the ISGLS criteria with grade B/C considered clinically relevant. A cut-off value for the prediction of PHLF was calculated using the receiver operating characteristic curve (ROC) analysis.

RESULTS

A total of 116 patients were included of which 27 (23%) suffered of PHLF. ROC values for the prediction of PHLF were 0.74 (0.63-0.86) for future liver remnant function and 0.63 (0.47-0.80) for volume. A cut-off for liver function was set at 8.5%/min, which resulted in a negative predictive value of 94% and positive predictive value of 41%.

CONCLUSIONS

Assessment of liver function with HBS had better predictive value for PHLF than liver volume in patients undergoing major liver resection for suspected PHC. The cut-off of 8.5%/min can help to select patients for portal vein embolization and might help to reduce postoperative liver failure.

The Pitfalls of Left Trisectionectomy or Central Bisectionectomy for Biliary Cancer: Anatomical Classification Based on the Ventral Branches of Segment VI Portal Vein Relative to the Right Hepatic Vein

BACKGROUNDS

Some patients have P6a running on the ventral side (Ventral-P6a), relative to the right hepatic vein (RHV).

STUDY DESIGN

Forty-one patients who underwent left trisectionectomy or central bisectionectomy for biliary cancer were enrolled. We compared the anatomical features using 3D images and surgical outcomes between patients with Ventral-P6a (n = 17) and those with P6a running on the dorsal side relative to the RHV (Dorsal-P6a; n = 25). Moreover, the liver volume by hand-tracing 2D axial images was compared to the volume calculated using the 3D images.

RESULTS

The frequency of complete exposure of RHV on the transection plane was less in Ventral-P6a (12 vs. 76%; p < 0.001), and the frequency of supraportal type of right posterior hepatic artery (RPHA, 29 vs. 4%, p = 0.020), the presence of inferior RHV (47 vs. 12%, p = 0.011), and the angle between the transection plane of segment VI and VII (S6-S7angle, 29.0° vs. 4.9°; p < 0.001) were greater in Ventral-P6a than in Dorsal-P6a. In Dorsal-P6a, the volume of posterior section calculated using 2D images was greater than that calculated using 3D images (404 vs. 370 mL; p = 0.004). The incidence of daily diuretic administration in Dorsal-P6a was greater than in Ventral-P6a (88 vs. 54%, p = 0.035).

CONCLUSION AND RELEVANCE

In Ventral-P6a, the complete exposure of RHV was rare in left trisectionectomy or central bisectionectomy. Surgeons should preoperatively recognize the course of RPHA, the presence of inferior RHV, and the S6-S7angle. In Dorsal-P6a, the volume of posterior section, which tended to be overestimated using 2D images, was smaller than that in Ventral-P6a.

Rat Model of the Associating Liver Partition and Portal Vein Ligation for Staged Hepatectomy (ALPPS) Procedure

Recent clinical data support an aggressive surgical approach to both primary and metastatic liver tumors. For some indications, like colorectal liver metastases, the amount of liver tissue left behind after liver resection has become the main limiting factor of resectability of large or multiple liver tumors. A minimal amount of functional tissue is required to avoid the severe complication of post-hepatectomy liver failure, which has high morbidity and mortality. Inducing liver growth of the prospective remnant prior to resection has become more established in liver surgery, either in the form of portal vein embolization by interventional radiologists or in the form of portal vein ligation several weeks prior to resection. Recently, it was shown that liver regeneration is more extensive and rapid, when the parenchymal transection is added to portal vein ligation in a first stage and then, after only one week of waiting, resection performed in a second stage (Associating Liver Partition and Portal vein ligation for Staged hepatectomy = ALPPS). ALPPS has rapidly become popular across the world, but has been criticized for its high perioperative mortality. The mechanism of accelerated and extensive growth induced by this procedure has not been well understood. Animal models have been developed to explore both the physiological and molecular mechanisms of accelerated liver regeneration in ALPPS. This protocol presents a rat model that allows mechanistic exploration of accelerated regeneration.

Hepatic atrophy following preoperative chemotherapy predicts hepatic insufficiency after resection of colorectal liver metastases

BACKGROUND & AIMS

For patients with colorectal liver metastases (CLM) undergoing major hepatectomy, extensive preoperative chemotherapy has been associated with increased morbidity and mortality. The impact of extensive chemotherapy on total liver volume (TLV) change is unclear. The aims of the current study were twofold: (1) to determine the change of TLV following preoperative chemotherapy in patients undergoing resection for CLM and (2) to investigate the correlations among TLV change, postoperative hepatic insufficiency (PHI), and death from liver failure.

METHODS

Clinicopathological features of patients with CLM who underwent preoperative chemotherapy and curative resection were reviewed (2008-2015). TLV change (degree of atrophy) was defined as the percentage difference of TLV (estimated by manual volumetry)/standardized liver volume (SLV) ratio: ([Pre-chemotherapy TLV]-[Post-chemotherapy TLV])×100÷SLV (%). Receiver operating characteristic (ROC) analysis was performed to decide the accurate cut-off value of degree of atrophy to predict PHI. The Cox proportional hazard model was performed to identify the predictors of severe degree of atrophy and PHI.

RESULTS

The study cohort consisted of 459 patients, of which 154 patients (34%) underwent extensive preoperative chemotherapy (≥7 cycles). ROC analysis identified the degree of atrophy ≥10% as an accurate cut-off to predict PHI, which was significantly correlated with ≥7 cycles of preoperative chemotherapy. Four factors independently predicted PHI: standardized future liver remnant ≤30% (odds ratio [OR] 4.03, p=0.019), high aspartate aminotransferase-to-platelet ratio index (OR 5.27, p=0.028), degree of atrophy ≥10% (OR 43.5, p<0.001), and major hepatic resection (OR 5.78, p=0.005). Degree of atrophy ≥10% was associated with increased mortality from liver failure (0% [0/374] vs. 15% [13/85], p<0.001).

CONCLUSION

Extensive preoperative chemotherapy induced significant atrophic change of TLV. Degree of atrophy ≥10% is an independent predictor of PHI and death in patients with CLM undergoing preoperative chemotherapy and resection.

LAY SUMMARY

Extensive preoperative chemotherapy for patients with colorectal liver metastases (CLM) could induce hepatic atrophy. A higher degree of atrophy is an independent predictor of postoperative hepatic insufficiency and death in patients with CLM undergoing preoperative chemotherapy and resection.