Hepatic Vein Embolization for Safer Liver Surgery: Insignificant Novelty or a Breakthrough?

Predicting response to neoadjuvant chemotherapy for colorectal liver metastasis using deep learning on prechemotherapy cross-sectional imaging

BACKGROUND AND OBJECTIVES

Deep learning models (DLMs) are applied across domains of health sciences to generate meaningful predictions. DLMs make use of neural networks to generate predictions from discrete data inputs. This study employs DLM on prechemotherapy cross-sectional imaging to predict patients' response to neoadjuvant chemotherapy.

METHODS

Adult patients with colorectal liver metastasis who underwent surgery after neoadjuvant chemotherapy were included. A DLM was trained on computed tomography images using attention-based multiple-instance learning. A logistic regression model incorporating clinical parameters of the Fong clinical risk score was used for comparison. Both model performances were benchmarked against the Response Evaluation Criteria in Solid Tumors criteria. A receiver operating curve was created and resulting area under the curve (AUC) was determined.

RESULTS

Ninety-five patients were included, with 33,619 images available for study inclusion. Ninety-five percent of patients underwent 5-fluorouracil-based chemotherapy with oxaliplatin and/or irinotecan. Sixty percent of the patients were categorized as chemotherapy responders (30% reduction in tumor diameter). The DLM had an AUC of 0.77. The AUC for the clinical model was 0.41.

CONCLUSIONS

Image-based DLM for prediction of response to neoadjuvant chemotherapy in patients with colorectal cancer liver metastases was superior to a clinical-based model. These results demonstrate potential to identify nonresponders to chemotherapy and guide select patients toward earlier curative resection.

Efficacy and perioperative safety of different future liver remnant modulation techniques: a systematic review and network meta-analysis

BACKGROUND

In daily clinical practice, different future liver remnant (FLR) modulation techniques are increasingly used to allow a liver resection in patients with insufficient FLR volume. This systematic review and network meta-analysis aims to compare the efficacy and perioperative safety of portal vein ligation (PVL), portal vein embolization (PVE), liver venous deprivation (LVD) and associating liver partition and portal vein ligation for staged hepatectomy (ALPPS).

METHODS

A literature search for studies comparing liver resections following different FLR modulation techniques was performed in MEDLINE, Embase and Cochrane Central, and pairwise and network meta-analyses were conducted.

RESULTS

Overall, 23 studies comprising 1557 patients were included. LVD achieved the greatest increase in FLR (17.32 %, 95% CI 2.49-32.15), while ALPPS was most effective in preventing dropout before the completion hepatectomy (OR 0.29, 95% CI 0.15-0.55). PVL tended to be associated with a longer time to completion hepatectomy (MD 5.78 days, 95% CI -0.67-12.23). Liver failure occurred less frequently after LVD, compared to PVE (OR 0.35, 95% CI 0.14-0.87) and ALPPS (OR 0.28, 95% CI 0.09-0.85).

DISCUSSION

ALPPS and LVD seem superior to PVE and PVL in terms of achieved FLR increase and subsequent treatment completion. LVD was associated with lower rates of post hepatectomy liver failure, compared to both PVE and ALPPS. A summary of the protocol has been prospectively registered in the PROSPERO database (CRD42022321474).

Application of the IDEAL framework in hepatopancreatobiliary surgery: a review of the literature

PURPOSE

To evaluate every stage of surgical innovation and generate high-quality research evidence, the IDEAL (Idea, Development, Exploration, Assessment, Long-term study) framework was developed. This study aimed to explore the application of the IDEAL framework in hepatopancreatobiliary surgery and identify factors limiting its dissemination.

METHODS

We conducted a citation search of 8 core IDEAL framework articles in PubMed, Embase, Web of Science, and Scopus databases from 2009 to 2022. Two independent reviewers screened and selected articles related to hepatopancreatobiliary surgery.

RESULTS

A total of 1621 articles were identified through citation search. Following screening, 132 articles were finally retained, including 75 original studies (57%) and 57 secondary studies (43%). Of the original studies, only 10 articles (13%) accurately applied the IDEAL framework in methodology, distributed as follows: 1 in pre-IDEAL stage (0), 2 in Idea stage (1), 7 in Development stage (2a), 1 in Exploration stage (2b), and no articles in Assessment and Long-term study stages (3, 4). In the secondary studies, 36 articles (63%) mentioned and discussed the IDEAL framework, and all supported its application.

CONCLUSIONS

The application of the IDEAL framework in hepatopancreatobiliary surgery is increasingly widespread, as evidenced by its substantial citation in numerous articles. However, the utilization of the IDEAL framework remains predominantly confined to the early stages of innovation in hepatopancreatobiliary surgery, coupled with instances of misapplication stemming from insufficient comprehension of the framework. Further efforts are necessary to extend the impact of the IDEAL framework and provide surgeons with comprehensive guidance for its judicious implementation.

Establishment of a Rat Model of Liver Venous Deprivation: Simultaneous Portal and Hepatic Vein Ligation

BACKGROUND AND AIMS

The aim was to establish a liver venous deprivation (LVD) model in rats, compare hepatic hypertrophy between LVD and associated liver partition and portal vein ligation for staged hepatectomy (ALPPS), and explore the underlying mechanisms.

METHODS

The LVD or extended-LVD (e-LVD) group received portal vein ligation (PVL) combined with hepatic vein ligation (HVL). The ALPPS or e-ALPPS group received PVL plus parenchyma ligation. Liver regeneration was assessed by measuring the liver weight and performing pathological analysis. Liver functions and the sphingosine kinase 1 (SPHK1)/sphingosine-1-phosphate (S1P)/sphingosine-1-phosphate receptor 1 (S1PR1) pathway were also investigated.

RESULTS

All future liver remnants (FLRs) in the ALPPS, e-ALPPS, LVD, and e-LVD groups exhibited significant hypertrophy compared with the control group. The LVD and e-LVD procedures induced similar liver hypertrophy than that in the corresponding ALPPS groups. Furthermore, the LVD and e-LVD methods led to obvious cytolysis in the venous-deprived lobes as well as a noticeable increase in serum transaminase levels, while no necrosis was observed in the ALPPS and e-ALPPS groups. SPHK1/S1P/S1PR1 pathway were distinctly activated after operation, especially in congestive/ischemic livers.

CONCLUSIONS

We describe the first rat model of LVD and e-LVD with simultaneously associated HVL and PVL. Compared with the ALPPS technique, the LVD or e-LVD procedure had a comparable overall effect on the hypertrophy response and a stronger effect on liver function. The SPHK1/S1P/S1PR1 pathway was involved in the LVD- or ALPPS-induced liver remodeling.

Simultaneous portal and hepatic vein embolization is better than portal embolization or ALPPS for hypertrophy of future liver remnant before major hepatectomy: A systematic review and network meta-analysis

BACKGROUND

Post-hepatectomy liver failure (PHLF) is the Achilles' heel of hepatic resection for colorectal liver metastases. The most commonly used procedure to generate hypertrophy of the functional liver remnant (FLR) is portal vein embolization (PVE), which does not always lead to successful hypertrophy. Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) has been proposed to overcome the limitations of PVE. Liver venous deprivation (LVD), a technique that includes simultaneous portal and hepatic vein embolization, has also been proposed as an alternative to ALPPS. The present study aimed to conduct a systematic review as the first network meta-analysis to compare the efficacy, effectiveness, and safety of the three regenerative techniques.

DATA SOURCES

A systematic search for literature was conducted using the electronic databases Embase, PubMed (MEDLINE), Google Scholar and Cochrane.

RESULTS

The time to operation was significantly shorter in the ALPPS cohort than in the PVE and LVD cohorts by 27 and 22 days, respectively. Intraoperative parameters of blood loss and the Pringle maneuver demonstrated non-significant differences between the PVE and LVD cohorts. There was evidence of a significantly higher FLR hypertrophy rate in the ALPPS cohort when compared to the PVE cohort, but non-significant differences were observed when compared to the LVD cohort. Notably, the LVD cohort demonstrated a significantly better FLR/body weight (BW) ratio compared to both the ALPPS and PVE cohorts. Both the PVE and LVD cohorts demonstrated significantly lower major morbidity rates compared to the ALPPS cohort. The LVD cohort also demonstrated a significantly lower 90-day mortality rate compared to both the PVE and ALPPS cohorts.

CONCLUSIONS

LVD in adequately selected patients may induce adequate and profound FLR hypertrophy before major hepatectomy. Present evidence demonstrated significantly lower major morbidity and mortality rates in the LVD cohort than in the ALPPS and PVE cohorts.

From liver surgery to liver transplant surgery: new developments in autotransplantation

PURPOSE OF REVIEW

In spite of substantial technical improvements and conceptual revolutions in advanced liver surgery, there are still straitened circumstances that pose difficulties for in-situ liver resections. Ex-vivo liver resection and autotransplantation (ELRA) is a hybrid technique combining experiences from conventional liver surgery and liver transplantation. This technique is becoming more comprehensive and popular among leading centers recently.

RECENT FINDINGS

Short-term and long-term outcomes are now the focus of the technique after more than a decade of cumulative progress and technical evolution. As the 5-year survival nowadays reaches over 80%, this technique is believed to be beneficial for advanced tumors. In recent years, ELRA has been applied by more centers on larger scales, and the learning curve was set at 53 cases. Progresses in disease selection, surgical indications, individualized outflow reconstruction, or autograft implantation, management of co-morbidities (e.g., Budd-Chiari syndrome, caval and/or neighboring organ involvements, obstructive jaundice) propelled the development of the technique.

SUMMARY

This hybrid liver surgery will benefit for carefully selected patients presented with advanced benign diseases and well-differentiated malignancies.

Prediction with functional liver volume assessment to achieve the resection limit after portal vein embolization in patients scheduled major hepatectomy

BACKGROUND

Preoperative portal vein embolization (PVE) stimulates liver hypertrophy and improves the safety of major hepatectomy. It is essential to predict the future remnant liver volume (FRLV) and resection limit following PVE. Previously, we reported that evaluating functional FRLV (fFRLV) using EOB-MRI could predict post-hepatectomy liver failure. In this study, we investigated the usefulness of fFRLV in predicting the achieving of adequate resection limit for safe hepatectomy following PVE.

METHODS

We included 55 patients who underwent PVE and were scheduled for major hepatectomy. We calculated the liver-to-muscle ratio in the remnant liver and fFRLV using EOB-MRI. We investigated the pre-PVE variables in determining the nonachievement of the resection limit.

RESULTS

The median observation period between PVE and the first evaluation was 21 days, and the median growth rate of FRLV was 26.4%. In 54.5% of patients, the resection limit of fFRLV (615 mL/m²) was achieved. In logistic regression and receiver-operating characteristic analyses, pre-PVE fFRLV (p < 0.001, area under the curve: 0.852) was the reliable predictor of achieving the resection limit; the cutoff value of pre-PVE fFRLV was 446 mL/m².

CONCLUSION

Pre-PVE fFRLV can be useful in predicting the achievement of adequate resection limit following PVE.

A meta-analysis evaluating contrast-enhanced intraoperative ultrasound (CE-IOUS) in the context of surgery for colorectal liver metastases

BACKGROUND

This study aimed to assess the outcomes of contrast-enhanced intraoperative ultrasound (CE-IOUS) for patients with colorectal liver metastases (CRLMs) undergoing surgery.

METHOD

A thorough literature search was performed in PubMed, Scopus, and Cochrane databases, in accordance with the PRISMA guidelines. The Odds Ratio, Weighted Mean Difference, and 95% Confidence Interval were evaluated, by means of Random-Effects model.

RESULTS

Eleven articles met the inclusion criteria and incorporated 497 patients. The present study shows that CE-IOUS is associated with higher sensitivity and accuracy compared with multidetector computed tomography (MDCT), magnetic resonance imaging (MRI), and intraoperative ultrasound (IOUS) in identifying CRLMs (p < 0.05). The positive predictive value was similar among the different modalities. Furthermore, new CRLMs were identified by CE-IOUS, thus affecting the surgical plan in 128 patients (51.8% of the patients with new CRLMs). Moreover, 91 patients (71%) underwent a more extensive hepatectomy and 15 patients (11.7%) were considered non-operable. Two alternative contrast agents, Sonazoid and Sonovue, were employed with similar sensitivity (p > 0.05).

CONCLUSION

These outcomes suggest the superiority of the CE-IOUS over MDCT, MRI, and IOUS for the staging of patients with CRLMs undergoing surgery. However, they should be treated with caution given the small number of the included studies.

Modern therapeutic approaches for the treatment of malignant liver tumours

Malignant liver tumours include a wide range of primary and secondary tumours. Although surgery remains the mainstay of curative treatment, modern therapies integrate a variety of neoadjuvant and adjuvant strategies and have achieved dramatic improvements in survival. Extensive tumour loads, which have traditionally been considered unresectable, are now amenable to curative treatment through systemic conversion chemotherapies followed by a variety of interventions such as augmentation of the healthy liver through portal vein occlusion, staged surgeries or ablation modalities. Liver transplantation is established in selected patients with hepatocellular carcinoma but is now emerging as a promising option in many other types of tumour such as perihilar cholangiocarcinomas, neuroendocrine or colorectal liver metastases. In this Review, we summarize the available therapies for the treatment of malignant liver tumours, with an emphasis on surgical and ablative approaches and how they align with other therapies such as modern anticancer drugs or radiotherapy. In addition, we describe three complex case studies of patients with malignant liver tumours. Finally, we discuss the outlook for future treatment, including personalized approaches based on molecular tumour subtyping, response to targeted drugs, novel biomarkers and precision surgery adapted to the specific tumour.

Choices of Therapeutic Strategies for Colorectal Liver Metastases Among Expert Liver Surgeons: A Throw of the Dice?

OBJECTIVE

To test the degree of agreement in selecting therapeutic options for patients suffering from colorectal liver metastasis (CRLM) among surgical experts around the globe.

SUMMARY/BACKGROUND

Only few areas in medicine have seen so many novel therapeutic options over the past decades as for liver tumors. Significant variations may therefore exist regarding the choices of treatment, even among experts, which may confuse both the medical community and patients.

METHODS

Ten cases of CRLM with different levels of complexity were presented to 43 expert liver surgeons from 23 countries and 4 continents. Experts were defined as experienced surgeons with academic contributions to the field of liver tumors. Experts provided information on their medical education and current practice in liver surgery and transplantation. Using an online platform, they chose their strategy in treating each case from defined multiple choices with added comments. Inter-rater agreement among experts and cases was calculated using free-marginal multirater kappa methodology. A similar, but adjusted survey was presented to 60 general surgeons from Asia, Europe, and North America to test their attitude in treating or referring complex patients to expert centers.

RESULTS

Thirty-eight (88%) experts completed the evaluation. Most of them are in leading positions (92%) with a median clinical experience of 25 years. Agreement on therapeutic strategies among them was none to minimal in more than half of the cases with kappa varying from 0.00 to 0.39. Many general surgeons may not refer the complex cases to expert centers, including in Europe, where they also engage in complex liver surgeries.

CONCLUSIONS

Considerable inconsistencies of decision-making exist among expert surgeons when choosing a therapeutic strategy for CRLM. This might confuse both patients and referring physicians and indicate that an international high-level consensus statements and widely accepted guidelines are needed.