Associating portal embolization and artery ligation to induce rapid liver regeneration in staged hepatectomy

Correlation between the liver transection line localization and future liver remnant hypertrophy in associating liver partition and portal vein ligation for staged hepatectomy

Background and aims

Colorectal liver metastases (CRLMs) represent the most prevalent form of secondary liver tumors, and insufficient future liver remnant (FLR) often leads to unresectability. To tackle this challenge, various methods for stimulating liver hypertrophy have been developed including portal vein embolization (PVE), associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) and the newest one, liver venous deprivation (LVD). ALPPS was thoroughly studied over the last decade and it has been shown to induce rapid and intensive FLR hypertrophy. The objective of this study was to assess whether the localization of the liver transection line during the initial stage of ALPPS correlates with the degree of FLR hypertrophy.

Methods

A retrospective, multicentric study was conducted, and we analyzed all consecutive patients with CRLMs who underwent ALPPS over the eight-year period. Patients were categorized into two groups based on the type of resection-right trisectionectomy (ERH) or right hemihepatectomy (RH) respectively. The degree of hypertrophy (DH), its correlation with FLR and postoperative outcomes were assessed.

Results

The cohort consisted of 136 patients (72 in the ERH group and 64 in the RH group). Baseline characteristics, hypertrophy interval, and total liver volume showed no significant differences between the groups. DH was greater in the ERH group (83.2% vs. 62.5%, p = 0.025). A strong negative correlation was observed between FLR volume and DH in both groups. Postoperative outcomes and one-year survival were comparable between the groups.

Conclusions

FLR hypertrophy is influenced by the localization of the liver transection line in ALPPS. Furthermore, correlation analysis indicated that a smaller estimated FLR is associated with greater DH. No statistical difference in outcomes was noted between the groups.

Chinese expert consensus on conversion therapy for hepatocellular carcinoma (2021 edition)

Recent advances in systemic and locoregional treatments for patients with unresectable or advanced hepatocellular carcinoma (HCC) have resulted in improved response rates. This has provided an opportunity for selected patients with initially unresectable HCC to achieve adequate tumor downstaging to undergo surgical resection, a 'conversion therapy' strategy. However, conversion therapy is a new approach to the treatment of HCC and its practice and treatment protocols are still being developed. Review the evidence for conversion therapy in HCC and develop consensus statements to guide clinical practice. Evidence review: Many research centers in China have accumulated significant experience implementing HCC conversion therapy. Preliminary findings and data have shown that conversion therapy represents an important strategy to maximize the survival of selected patients with intermediate stage to advanced HCC; however, there are still many urgent clinical and scientific challenges for this therapeutic strategy and its related fields. In order to summarize and learn from past experience and review current challenges, the Chinese Expert Consensus on Conversion Therapy for Hepatocellular Carcinoma (2021 Edition) was developed based on a review of preliminary experience and clinical data from Chinese and non-Chinese studies in this field and combined with recommendations for clinical practice. Sixteen consensus statements on the implementation of conversion therapy for HCC were developed. The statements generated in this review are based on a review of clinical evidence and real clinical experience and will help guide future progress in conversion therapy for patients with HCC.

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.

Downstaging Conversion Therapy in Patients With Initially Unresectable Advanced Hepatocellular Carcinoma: An Overview

The high mortality rate associated with hepatocellular carcinoma (HCC) is partly due to the high proportion of patients who present with advanced stage disease at diagnosis, for whom there are limited treatment options. For selected patients with initially unresectable HCC, locoregional and/or systemic treatments can result in tumor downstaging and consequently provide opportunities for surgical intervention and the potential for long-term survival. Therefore, the key aim of 'conversion therapy' is to reduce tumor burden so that patients become amenable to surgical resection. Various therapies have been investigated as candidates for downstaging patients with potentially resectable HCC including transarterial chemoembolization, transarterial radioembolization with yttrium-90 microspheres, radiotherapy, systemic therapies and combination or multimodality treatment approaches. However, downstaging conversion therapy remains controversial and there are several challenges such as defining the criteria used to identify the population of patients who are 'potentially resectable', the criteria used to define successful downstaging, and the optimum treatment approach to maximize the success of downstaging therapy. In this review article, we summarize clinical experience and evidence of downstaging conversion treatment in patients identified as having 'potentially resectable' HCC.

The evolution of surgery for colorectal liver metastases: A persistent challenge to improve survival

Only a few decades ago, the opinion that colorectal liver metastases were a palliative diagnosis changed. In fact, previously, the prevailing view was strongly resistant against resecting colorectal liver metastases. Constant technical improvement of liver surgery and, much later, effective chemotherapy allowed for a successful wider application of surgery. The clinical use of portal vein embolization was the starting signal of regenerative liver surgery, where insufficient liver volume can be expanded to an extent where safe resection is possible. Today, a number of these techniques including portal vein ligation, associating liver partition and portal vein ligation for staged hepatectomy, and bi-embolization (portal and hepatic vein) can be successfully used to address an insufficient future liver remnant in staged resections. It turned out that the road to success is embedding surgery in a well-orchestrated oncological concept of controlling systemic disease. This concept was the prerequisite that meant liver transplantation could enter the treatment strategy for colorectal liver metastases, ending up with a 5-year overall survival of 80% in highly selected cases. In particular, techniques combining principles of 2-stage hepatectomy and liver transplantation, such as "resection and partial liver segment 2-3 transplantation with delayed total hepatectomy" (RAPID) are on the rise. These techniques enable the use of partial liver grafts with primarily insufficient liver volume. All this progress also prompted a number of innovative local therapies to address recurrences ultimately transferring colorectal liver metastases from instantly deadly into a chronic disease in some cases.

Assessment of remnant liver function and volume after selective ligation of portal vein and hepatic artery in a rat model

Purpose:

To evaluate liver regeneration after selective ligation of portal vein and hepatic artery by 3D Computed Tomography in an experimental model.

Methods:

Sixteen Wistar rats were randomized into four equal groups: Group I- control (sham), Group II- isolated selective ligation of the hepatic artery, Group III- isolated selective ligation of the portal vein and Group IV- combined ligation of portal vein and hepatic artery. Before procedure and five days after a 3D CT Scan was performed to analyze the hypertrophy, weight and function of the remnant liver.

Results:

The largest regeneration rate and increase of weight in the hypertrophied lobe was detected in group IV, the first with an average of 3.99 (p=0.006) and the last varying from 6.10g to 9.64g (p=0.01). However, total liver weight and the R1 ratio (Hypertrophied Lobe Weight/Total Liver Weight) was higher in group III (P<0.001) when compared with groups I, II and IV and showed no difference between them. The immunohistochemical examination with PCNA also found higher percentages with statistical significance differences in rats of groups III and IV. It was possible to confirm a strong correlation between hypertrophied lobe weight and its imaging volumetric study. Liver function tests only showed a significant difference in serum gamma-glutamyltransferase and phosphorous.

Conclusion:

There is a largest liver regeneration after combined ligation of portal vein and hepatic artery and this evidence may improve the knowledge of surgical treatment of liver injuries, with a translational impact in anima nobile.

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

Aim: To explore clinical factors associated with extent of liver regeneration after hemihepatectomy to treat hepatocellular carcinoma (HCC).

Methods: Future liver remnant volume (as a percentage of functional liver volume, %FLRV) and remnant liver volume were measured preoperatively and at 1, 5, 9, and 13 weeks postoperatively.

Results: After hepatectomy, 1 of 125 patients (0.8%) died within 3 months, 13 (10.4%) experienced liver failure, and 99 (79.2%) experienced complications. %FLRV was able to predict liver failure with an area under the receiver operating characteristic curve of 0.900, and a cut-off value of 42.7% showed sensitivity of 85.7% and specificity of 88.6%. Postoperative median growth ratio was 21.3% at 1 week, 30.9% at 5 weeks, 34.6% at 9 weeks, and 37.1% at 13 weeks. Multivariate analysis identified three predictors associated with liver regeneration: FLRV < 601 cm³, %FLRV, and liver cirrhosis. At postoperative weeks (POWs) 1 and 5, liver function indicators were significantly better among patients showing high extent of regeneration than among those showing low extent, but these differences disappeared by POW 9.

Conclusions: FLRV, %FLRV, and liver cirrhosis strongly influence extent of liver regeneration after hepatectomy. %FLRV values below 42.7% are associated with greater risk of post-hepatectomy liver failure.

Partial ALPPS with a longer wait between procedures is safe and yields adequate future liver remnant hypertrophy

Backgrounds/Aims

Associating Liver Partition and Portal Vein Ligation for Staged Hepatectomy (ALPPS) has generated controversy due to high morbidity and mortality. We present our series of patients with 30-40% parenchymal transection and minimal hilar dissection.

Methods

Patients who had partial ALPPS between April 2015 and April 2016 were included. Patients with colorectal liver metastases (CRLM) had their future liver remnants (FLR) cleared with metastasectomies. The liver was divided along the future line of transection to 30-40%, right portal vein was stapled and divided without extensive hilar dissection, with minimal handling of right liver, which was not mobilised. We preserved the middle hepatic vein. Data were collected prospectively for hypertrophy of the FLR, morbidity and mortality.

Results

Among the 8 patients (age 25-68) investigated, one patient with cholangiocarcinoma had portal vein embolization prior to partial ALPPS. All patients completed two stages with adequate FLR hypertrophy at a median of 28 days. No mortality was found. The median length of stay after stages 1 and 2 was 9 and 9.6 days, respectively. The median increase in FLR was 38%.

Conclusions

A limited transection of 30-40%, minimal hilar dissection and longer wait between stages yielded adequate FLR hypertrophy with low morbidity and no mortality.

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.

A predictive scoring system for insufficient liver hypertrophy after preoperative portal vein embolization

BACKGROUND

The factors which affect hypertrophy of the future liver remnant after portal vein embolization remain unclear. The aim of this study was to clarify the clinical factors affecting the hypertrophy rate after portal vein embolization and to develop a scoring system predicting insufficient liver hypertrophy.

METHODS

The cases of a total of 152 patients who underwent portal vein embolization of the right portal branch between 2006 and 2016 were reviewed retrospectively. The score to predict insufficient (<25%) hypertrophy was established based on logistic regression analyses of the clinical parameters before portal vein embolization.

RESULTS

After portal vein embolization, the future liver remnant volume, expressed as the median (range), significantly increased from 364 (151-801) mL, 33% (18%-54%), to 451 (242-866) mL, 42% (26%-65%). The median hypertrophy rate was 24% (-5% to 96%). A preoperative predictive scoring system for insufficient liver hypertrophy was constructed using the following 3 factors: an initial future liver remnant volume ≥35% (2 points), alkaline phosphatase ≥450 IU/dL (1 point), and cholinesterase <220 mg/dL (1 point). The constructed scoring system indicated the proportion of patients with insufficient liver hypertrophy (<25%) to be 6 out of 42 (14%) in the low-score group (0 points), 44 out of 77 (57%) in the medium-score group (1-2 points), and 30 out of 33 (91%) in the high-score group (3-4 points). The hypertrophy rate of future liver remnant was different among the 3 groups (low-score group, 38.9% [-2.4% to 81.4%]; medium-score group, 22.7% [-5.1% to 95.5%]; high-score group, 18.2% [2.4%-30.7%]) (P < .001).

CONCLUSION

The constructed scoring system was able to stratify patients before portal vein embolization according to the possibility of developing insufficient liver hypertrophy.

Recent Advances in Chemotherapy and Surgery for Colorectal Liver Metastases

BACKGROUND

The liver is the most common site of metastases for colorectal cancer, and combined resection with systemic chemotherapy is the most effective strategy for survival. The aim of this article is to provide a comprehensive summary on four hot topics related to chemotherapy and surgery for colorectal liver metastases (CLM), namely: (1) chemotherapy-related liver injuries: prediction and impact, (2) surgery for initially unresectable CLM, (3) the emerging role of RAS mutations, and (4) the role of hepatic arterial infusion of chemotherapy (HAIC).

SUMMARY AND KEY MESSAGES

(1) The use of chemotherapy before liver resection for CLM leads to drug-specific hepatic toxicity, which negatively impacts posthepatectomy outcomes. (2) Curative liver resection of initially unresectable CLM following conversion chemotherapy should be attempted whenever possible, provided that a safe future liver remnant volume is achieved. (3) For CLM, RAS mutation status is needed to guide the use of targeted chemotherapy with anti-epithelial growth factor receptor (EGFR) agents, and is a major prognostic factor that may contribute to optimize surgical strategy. (4) HAIC agents increase the rate of objective response and the rate of complete pathological response.