Remnant Liver Ischemia as a Prognostic Factor for Cancer-Specific Survival After Resection of Colorectal Liver Metastases

Adverse effects of graft congestion and ameliorative effects of hepatocyte growth factor after liver transplantation in rats

Living donor liver transplantation (LT) and deceased donor split-LT often result in congestion within liver grafts. The regenerative process and function of congested areas, especially graft congestion associated with LT, are not well understood. Therefore, we created new rat models with congested areas in partially resected livers and orthotopically transplanted these livers into syngeneic rats to observe liver regeneration and function in congested areas. This study aimed to compare liver regeneration and the function of congested areas after liver resection and LT, and to explore a new approach to ameliorate the adverse effects of graft congestion. Although the congested areas after liver resection regenerated normally on postoperative day 7, the congested areas after LT had poor regeneration with abscess development on postoperative day 7. Necrotic areas in congested areas were larger after LT than after liver resection on postoperative days 1, 3, and 7 ( p < 0.05, p < 0.05, and p < 0.01, respectively). Although congested areas after liver resection did not affect survival, in the LT model, the survival of rats with congested areas was significantly poorer even with larger grafts than that of rats with smaller noncongested grafts ( p = 0.04). Hepatocyte growth factor administration improved the survival rate of rats with congested grafts from 41.7% to 100%, improved the regeneration of congested areas, and significantly reduced the size of necrotic areas ( p < 0.05). Thus, congested areas in liver grafts may negatively impact recipients. Short-term administration of hepatocyte growth factor may improve postoperative outcomes of recipients with graft congestion and contribute to more effective use of liver grafts (approval number: MedKyo-23137, Institutional Ethics Committee/Kyoto University).

Anatomic Versus Non-anatomic Liver Resection for Intrahepatic Cholangiocarcinoma: A Systematic Review and Patient-Level Meta-Analysis

BACKGROUND

The current standard treatment for intrahepatic cholangiocarcinoma (ICC) involves complete liver resection with negative surgical margins and lymphadenectomy, followed by adjuvant chemotherapy. Debate is ongoing regarding the necessity of systematic anatomic resection (AR). This study aimed to summarize existing literature to determine whether AR leads to better oncologic outcomes than non-AR for patients with resectable ICC.

METHODS

A systematic literature review (PubMed, Embase, and Google Scholar) was performed until December 2023. Only studies comparing the oncologic outcomes of AR and non-AR for ICC using propensity score matching or inverse probability of treatment weighting were considered. A meta-analysis of aggregated data for perioperative variables and a reconstructed patient-level meta-analysis for survival data were performed.

RESULTS

Five articles were gathered (n = 930 patients after matching: 465 AR/465 non-AR patients). The overall survival (OS) rates were higher in the AR group than in the non-AR group at 1, 3, and 5 years (71.5%, 46.1% and 34.3% vs. 63.6%, 32.9%, and 24.8%, respectively; hazard ratio [HR] 0.74; 95% CI 0.63-0.87; P < 0.001). The same results were observed for the disease-free survival (DFS) rates (58.3%, 33.4%, and 24.5% for AR vs. 45.6%, 23.1%, and 17.4% for non-AR; HR 0.74; 95% CI 0.63-0.86; P < 0.001). The results were confirmed in the two-stage meta-analysis for OS (HR 0.73; P < 0.001) and DFS (HR 0.73; P < 0.001). No differences were observed between the two approaches in terms of operative time, intraoperative blood loss, overall and major morbidity, and hospital length of stay.

CONCLUSIONS

By pooling the available evidence, the current study demonstrated that AR for ICC patients is associated with better OS and DFS without any negative impact on postoperative outcomes.

Efficacy of Augmented Reality Combined with Indocyanine Green Fluorescence Imaging Guided Laparoscopic Segmentectomy for Hepatocellular Carcinoma

BACKGROUND

The internal anatomy of the liver is extremely complex. Laparoscopic anatomical segmentectomy requires reference to the position and alignment of intrahepatic vascular. However, the surface of the liver lacks anatomical landmarks and the liver segment boundaries cannot be identified with the naked eye. Augmented reality navigation (ARN) and indocyanine green fluorescence imaging (FI) are emerging navigation tools in liver resection. This study aimed to explore the efficacy and application value of laparoscopic anatomical segmentectomy guided by ARN combined with indocyanine green FI.

STUDY DESIGN

Ninety-eight patients who were diagnosed with hepatocellular carcinoma and underwent laparoscopic anatomical segmentectomy from January 2018 to January 2022 were retrospectively analyzed. They were divided into the ARN-FI group (45 patients) and the non-ARN-FI group (53 patients) based on whether ARN combined with FI was applied during the operation. The differences in intraoperative and postoperative outcomes were compared.

RESULTS

There was no significant difference in preoperative baseline data and postoperative complication rates between the 2 groups. Compared with the non-ARN-FI group, the ARN-FI group had much lower intraoperative blood loss (100 vs 200 mL, p = 0.005) and a lower incidence of remnant liver ischemia (13.3% vs 30.2%, p = 0.046). The 1- and 3-year disease-free survival rates in the ARN-FI and non-ARN-FI groups were 91.01% vs 71.15% and 70.01% vs 52.46%, respectively; the differences between the 2 groups were statistically significant (p = 0.047).

CONCLUSIONS

The ARN-FI technology provides a more standardized approach for liver parenchyma section during laparoscopic liver resection, effectively minimizing intraoperative blood loss, reducing postoperative remnant liver ischemia, and improving oncological prognosis. This method is safe and feasible and has good clinical application prospects.

Parenchyma Sparing Anatomic Liver Resections (Bi- and Uni-Segmentectomies) for Liver Tumours in Children-A Single-Centre Experience

Purpose: To present a single-centre experience in bi- and uni-segmentectomies for primary liver tumours in children.

METHODS

This study included 23 patients that underwent (bi)segmentectomy. There were 15 malignant tumours (hepatoblastoma-13 patients), 7 benign tumours, and 1 calcifying nested stromal epithelial tumour.

RESULTS

The median tumour diameter was 52 mm (range 15-170 mm). Bisegmentectomy 2-3 was most frequently performed (seven patients), followed by bisegmentectomy 5-6 (four patients). The median operative time was 225 min (range 95-643 min). Intraoperative complications occurred in two patients-small bowel perforation in one and an injury of the small peripheral bile duct resulting in biloma in the other. The median resection margin in patients with hepatoblastoma was 3 mm (range 1-15 mm). Microscopically negative margin status was achieved in 12 out of 13 patients. There were two recurrences. After a median follow-up time of 38 months (range 12-144 months), all 13 patients with HB were alive with no evidence of disease. Two relapsed patients were alive with no evidence of disease.

CONCLUSIONS

From the available literature and data presented here, we propose that (bi)segmentectomy can become a viable surgical option in carefully selected paediatric patients and is sufficient to achieve a cure. Further studies evaluating the impact of parenchymal preservation surgery on surgical and oncological outcome should be conducted with a larger dataset.

Reappraisal of anatomical liver resection for hepatoblastoma in children

Background

The principle of hepatoblastoma (HB) treatment is complete resection. The removal of tumor-bearing section(s) or hemiliver is widely accepted. However, neither the standardized anterior approach for right hepatectomy nor parenchymal sparing anatomical liver resection has been described for HB.

Methods

We retrospectively reviewed the clinical course of two pediatric HB patients who underwent extended right hepatectomy using the anterior approach with the liver hanging maneuver and one who underwent parenchymal sparing anatomical liver resection of S4 apical+S8 ventral/dorsal+S7. The critical aspects of surgical techniques are described in detail.

Results

In all three patients, R0 resection was achieved without complications and are currently alive without recurrence after an average follow-up of 23 months. Intraoperative cardiac hemodynamics were stable, even in a trisomy 18 patient with cardiac disease.

Conclusions

Our findings suggest that these innovative techniques established in adults are safe and feasible for HB in children. These techniques also allow optimal anatomical liver resection to accomplish curative surgery while maintaining the functional reserve of the remnant liver.

The role of ischaemia-reperfusion injury and liver regeneration in hepatic tumour recurrence

The risk of cancer recurrence after liver surgery mainly depends on tumour biology, but preclinical and clinical evidence suggests that the degree of perioperative liver injury plays a role in creating a favourable microenvironment for tumour cell engraftment or proliferation of dormant micro-metastases. Understanding the contribution of perioperative liver injury to tumour recurrence is imperative, as these pathways are potentially actionable. In this review, we examine the key mechanisms of perioperative liver injury, which comprise mechanical handling and surgical stress, ischaemia-reperfusion injury, and parenchymal loss leading to liver regeneration. We explore how these processes can trigger downstream cascades leading to the activation of the immune system and the pro-inflammatory response, cellular proliferation, angiogenesis, anti-apoptotic signals, and release of circulating tumour cells. Finally, we discuss the novel therapies under investigation to decrease ischaemia-reperfusion injury and increase regeneration after liver surgery, including pharmaceutical agents, inflow modulation, and machine perfusion.

Partial Hepatic Vein Occlusion and Venous Congestion in Liver Exploration Using a Hyperspectral Camera: A Proposal for Monitoring Intraoperative Liver Perfusion

INTRODUCTION

The changes occurring in the liver in cases of outflow deprivation have rarely been investigated, and no measurements of this phenomenon are available. This investigation explored outflow occlusion in a pig model using a hyperspectral camera.

METHODS

Six pigs were enrolled. The right hepatic vein was clamped for 30 min. The oxygen saturation (StO₂%), deoxygenated hemoglobin level (de-Hb), near-infrared perfusion (NIR), and total hemoglobin index (THI) were investigated at different time points in four perfused lobes using a hyperspectral camera measuring light absorbance between 500 nm and 995 nm. Differences among lobes at different time points were estimated by mixed-effect linear regression.

RESULTS

StO₂% decreased over time in the right lateral lobe (RLL, totally occluded) when compared to the left lateral (LLL, outflow preserved) and the right medial (RML, partially occluded) lobes (p < 0.05). De-Hb significantly increased after clamping in RLL when compared to RML and LLL (p < 0.05). RML was further analyzed considering the right portion (totally occluded) and the left portion of the lobe (with an autonomous draining vein). StO₂% decreased and de-Hb increased more smoothly when compared to the totally occluded RLL (p < 0.05).

CONCLUSIONS

The variations of StO₂% and deoxy-Hb could be considered good markers of venous liver congestion.

Intentional R1 resection of liver metastases: A new treatment paradigm for patients with advanced colorectal cancer based on a propensity score-Matched case-control analysis

BACKGROUND

Clinical outcomes of colorectal cancer (CRC) patients after an incomplete microscopic (R1) resection of liver metastases may not differ from those following a microscopically margin negative (R0) resection, when the latest is not feasible because of anatomic issues. We aimed at comparing the clinical outcomes of CRC patients with an intentional R1 or with a R0 resection of liver metastases.

METHODS

All patients with advanced in CRC and liver metastases consecutively treated by liver resection between February 2005 and January 2019 at in the department of Digestive and Hepatobiliary Surgery of Henri Mondor University Hospital (Créteil, France) were included in this retrospective case-control study. Overall survival (OS) and event-free survival (EFS) were compared between patients who underwent an intentional (pre-operative decision) R1 resection (iR1) to those who had a R0 resection of liver metastases. To account for confounding, comparison between the 2 groups was performed after adjustment using propensity score analysis.

RESULTS

Twenty-six CRC patients treated by iR1 resection of liver metastases were compared to 98 patients treated by R0 resection. Median OS reached 39 months [95% confidence interval (CI): 25-67] and 63 months [95% CI: 52-76] in the iR1 and R0 groups, respectively. After adjustment by inverse probability of treatment weighting, patients' OS and EFS did not differ significantly between the iR1 and R0 groups (hazard ratio (HR): 1.19 [0.54-2.62] and 1.67 [0.93-3.03]), respectively.

CONCLUSION

iR1 resection of liver metastases in advanced CRC patients is an acceptable therapeutic strategy, when R0 resection is not feasible.

Hepatocyte SGK1 activated by hepatic ischemia-reperfusion promotes the recurrence of liver metastasis via IL-6/STAT3

BACKGROUND

Liver metastasis is the leading cause of death in patients with colorectal cancer (CRC). Surgical resection of the liver metastases increases the incidence of long-term survival in patients with colorectal liver metastasis (CRLM). However, many patients experience CRLM recurrence after the initial liver resection. As an unavoidable pathophysiological process in liver surgery, liver ischemia-reperfusion (IR) injury increases the risk of tumor recurrence and metastasis.

METHODS

Colorectal liver metastasis (CRLM) mouse models and mouse liver partial warm ischemia models were constructed. The levels of lipid peroxidation were detected in cells or tissues. Western Blot, qPCR, elisa, immunofluorescence, immunohistochemistry, scanning electron microscope, flow cytometry analysis were conducted to evaluate the changes of multiple signaling pathways during CRLM recurrence under liver ischemia-reperfusion (IR) background, including SGK1/IL-6/STAT3, neutrophil extracellular traps (NETs) formation, polymorphonuclear myeloid-derived suppressor cell (PMN-MDSC) infiltration.

RESULTS

Hepatocyte serum/glucocorticoid regulated kinase 1 (SGK1) was activated in response to hepatic ischemia-reperfusion injury to pass hepatocyte STAT3 phosphorylation and serum amyloid A (SAA) hyperactivation signals in CRLM-IR mice, such regulation is dependent on SGK-activated IL-6 autocrine. Administration of the SGK1 inhibitor GSK-650394 further reduced ERK-related neutrophil extracellular traps (NETs) formation and polymorphonucler myeloid-derived suppressor cells (PMN-MDSC) infiltration compared with targeting hepatocyte SGK1 alone, thereby alleviating CRLM in the context of IR.

CONCLUSIONS

Our study demonstrates that hepatocyte and immune cell SGK1 synergistically promote postoperative CRLM recurrence in response to hepatic IR stress, and identifies SGK1 as a translational target that may improve postoperative CRLM recurrence.

Molecular Mechanisms of Ischaemia-Reperfusion Injury and Regeneration in the Liver-Shock and Surgery-Associated Changes

Hepatic ischemia-reperfusion injury (IRI) represents a major challenge during liver surgery, liver preservation for transplantation, and can cause hemorrhagic shock with severe hypoxemia and trauma. The reduction of blood supply with a concomitant deficit in oxygen delivery initiates various molecular mechanisms involving the innate and adaptive immune response, alterations in gene transcription, induction of cell death programs, and changes in metabolic state and vascular function. Hepatic IRI is a major cause of morbidity and mortality, and is associated with an increased risk for tumor growth and recurrence after oncologic surgery for primary and secondary hepatobiliary malignancies. Therapeutic strategies to prevent or treat hepatic IRI have been investigated in animal models but, for the most part, have failed to provide a protective effect in a clinical setting. This review focuses on the molecular mechanisms underlying hepatic IRI and regeneration, as well as its clinical implications. A better understanding of this complex and highly dynamic process may allow for the development of innovative therapeutic approaches and optimize patient outcomes.

Dorsal vs ventral approach to the middle hepatic vein during laparoscopic left hemihepatectomy: multicenter retrospective observational study

BACKGROUND

Left hemihepatectomy requires exposure of the middle hepatic vein (MHV) at the cutting-surface. Two procedures are used to approach the MHV: a conventional ventral approach and a laparoscopy-specific dorsal approach. This multicenter retrospective observational study aimed to evaluate the perioperative outcomes of these two procedures.

METHODS

Clinical records of 38 consecutive patients that underwent laparoscopic left hemihepatectomy in four university hospitals between 2016 and 2021 were retrospectively reviewed. Outcome measurements were operative blood loss, operating time, trend of postoperative laboratory data within 7 days after hepatectomy, and postoperative complications. Quality of MHV exposure was also evaluated and compared by three-grade evaluation (excellent/good/poor) using recorded still images of the cut-surface of the remnant liver (n = 35).

RESULTS

Dorsal and ventral approaches were performed in 9 and 29 patients, respectively. Median operating time was 316 min (dorsal) and 314 min (ventral) (P = 0.71). Median operative blood loss was 45 ml (dorsal) and 105 ml (ventral) (P = 0.10). Two patients in the ventral approach group had bleeding in excess of 500 ml, which was not seen in the dorsal approach group. Excellent/good/poor MHV appearance on the cutting-surface was observed in 5/3/1 patients in the dorsal approach group, respectively, and in 7/8/11 patients in the ventral approach group, respectively (P = 0.03). In the ventral approach group, significant increases of aspartate aminotransferase (on postoperative day 1 and day 4/5) and of alanine aminotransferase (on postoperative day 2/3 and 4/5) were observed (P < 0.05). Postoperative complications were observed only in the ventral approach group (n = 3).

CONCLUSIONS

The dorsal approach could achieve safe and precise anatomical left hemihepatectomy with operation time and operative blood loss comparable to the conventional ventral approach.

Utilization of elderly donors in liver transplantation for patients with hepatocellular carcinoma: A national retrospective cohort study of China

BACKGROUND

Profound organ shortages worldwide have led to the increased utilization of marginal organs from older individuals. However, the effectiveness of liver transplantation (LT) with organs from elderly donors for patients with hepatocellular carcinoma (HCC) remains controversial. The objective of the current study was to assess the overall survival (OS) and disease-free survival (DFS) of patients with HCC following LT using grafts from deceased donors over 60 years old.

MATERIAL AND METHODS

Patients with HCC who underwent LT between 2015 and 2018 were identified in the China Liver Transplant Registry database. The overall survival and disease-free survival of older liver donors (OLDs) were compared with those of younger liver donors (YLDs) after propensity score matching.

RESULTS

From January 2015 to December 2018, a total of 4971 HCC patients were enrolled in the study according to the screening criteria. The absolute and relative utilization of liver grafts from elderly patients over 60 years for HCC patients increased every year, from 65 (9.3%) in 2015 to 268 (14.5%) in 2018. Disease-free survival (DFS) was significantly lower in HCC patients with elderly donors (both P < 0.05) after propensity score matching. The OLD group had worse DFS than YLD group if patients had tumors beyond the Milan criteria (P < 0.05).

CONCLUSIONS

The use of older donors for LT has been growing quickly in the last few years in China. Grafts from older donors can be safely used in HCC recipients with similar OS and comparable perioperative complications. However, further investigation into whether older donor has an impact on recurrence is warranted, especially among those with tumors beyond the Milan criteria.

Laparoscopic liver resection for liver metastasis of leiomyosarcoma of the thigh: a case report

Background

Although there is no established treatment strategy for liver metastasis of leiomyosarcoma, liver resection has been reported to be effective in some cases. However, almost all liver resections performed for liver metastasis of primary leiomyosarcoma are reported to be open resections, and there are few reports of liver resection performed by laparoscopy. Here, we report a case of laparoscopic liver resection for liver metastasis of a leiomyosarcoma in the right thigh.

Case presentation

An 80-year-old man was diagnosed with leiomyosarcoma of the right thigh with liver metastasis. The primary tumor was first resected, and he was discharged on the 25th postoperative day. Four months after primary tumor resection, a laparoscopic right posterior sectionectomy was performed. There were no postoperative complications, and the patient was discharged on the 11th postoperative day with a histopathological diagnosis of liver metastasis of leiomyosarcoma and negative resection margins. Currently, 9 months have passed since the resection of the primary tumor, and 5 months have passed since the laparoscopic liver resection; there is no recurrence.

Conclusions

The liver metastasis of leiomyosarcoma was successfully removed, with good short-term outcomes after the laparoscopic liver resection. Laparoscopic liver resection seems to be effective for liver metastasis of leiomyosarcoma, which is characterized by a high recurrence rate after surgery. However, more case studies may be necessary to examine the effectiveness and long-term results of laparoscopic liver resection for the treatment of liver metastasis of leiomyosarcoma.

The Applications of 3D Imaging and Indocyanine Green Dye Fluorescence in Laparoscopic Liver Surgery

Laparoscopic liver resections have gained widespread popularity among hepatobiliary surgeons and is nowadays performed for both standard and more complex hepatectomies. Given the increased technical challenges, preoperative planning and intraoperative guidance is pivotal in laparoscopic surgery to safely carry out complex and oncologically safe hepatectomies. Modern tools can help both preoperatively and intraoperatively and allow surgeons to perform more precise hepatectomies. Preoperative 3D reconstructions and printing as well as augmented reality can increase the knowledge of the specific anatomy of the case and therefore plan the surgery accordingly and tailor the procedure on the patient. Furthermore, the indocyanine green retention dye is an increasingly used tool that can nowadays improve the precision during laparoscopic hepatectomies, especially when considering anatomical resection. The use of preoperative modern imaging and intraoperative indocyanine green dye are key to successfully perform complex hepatectomies such as laparoscopic parenchymal sparing liver resections. In this narrative review, we discuss the aspects of preoperative and intraoperative tools that are nowadays increasingly used in experienced hepatobiliary centers.

Laparoscopic anatomical liver resection for malignancies using positive or negative staining technique with intraoperative indocyanine green-fluorescence imaging

BACKGROUND

Indications for a minimally invasive resections are increasing worldwide, but respecting anatomical planes during intraparenchymal transection is demanding. Intraoperative ICG fluorescence staining of liver parenchyma has been introduced as a tool for real-time intraoperative guidance. The aim of this study is to make a systematic review of the current relevant literature on indications, techniques, and results of laparoscopic anatomical liver resection (LALR) using intraoperative indocyanine green (ICG) fluorescence for positive and negative staining of liver segments in patients affected by liver malignancies.

METHODS

Electronic bibliographical databases (MEDLINE and PubMed) were searched according to the PRISMA criteria. English language articles meeting the selection criteria and published until June 2020 were retrieved and reviewed.

RESULTS

a total of 86 articles were initially found and 11 articles were finally included in the analysis with a total of 83 patients treated. Sixty-two patients (74.6%) underwent mono-segmentectomies. Thirty-five patients (42.1%) underwent the positive staining technique, and forty-eight patients (57.8%) the negative staining technique.

CONCLUSIONS

The positive or negative indocyanine green staining technique with real-time fluorescence guidance is an emerging and promising approach. However, the technique has to be standardized and advantages in terms of oncologic results still need validation in further studies.

What is the optimal surgical treatment for hepatocellular carcinoma beyond the debate between anatomical versus non-anatomical resection?

The optimal type of hepatectomy for hepatocellular carcinoma (HCC)-anatomical or non-anatomical resection-remains controversial despite numerous comparative studies. There are common fundamental issues in published studies comparing anatomical resection with non-anatomical resection: (1) confounding by indication, (2) setting primary outcomes, and (3) a lack of a clear definition of non-anatomical resection. This degrades the quality of the comparison of the two types of surgery. To measure the therapeutic effect of hepatectomy, it is essential to understand the accumulated knowledge underlying these issues, such as the mechanism of hepatocellular carcinoma spread, tumor blood flow drainage theory, and the three patterns of hepatocellular carcinoma recurrence: (1) local intrahepatic metastasis, (2) systemic metastasis, and (3) multicentric carcinogenesis recurrence. Based on evidence that the incidence of local intrahepatic metastasis was so low it was almost negligible, the therapeutic effect of anatomical resection on the oncological survival was determined to be similar to that of non-anatomical resection. Recent research progress demonstrating the clinical impact of subclinical dissemination of HCC after surgery may stimulate new debate on the optimal surgical treatment for HCC beyond the comparison of anatomical and non-anatomical resection.

New Insights in Mechanisms and Therapeutics for Short- and Long-Term Impacts of Hepatic Ischemia Reperfusion Injury Post Liver Transplantation

Liver transplantation has been identified as the most effective treatment for patients with end-stage liver diseases. However, hepatic ischemia reperfusion injury (IRI) is associated with poor graft function and poses a risk of adverse clinical outcomes post transplantation. Cell death, including apoptosis, necrosis, ferroptosis and pyroptosis, is induced during the acute phase of liver IRI. The release of danger-associated molecular patterns (DAPMs) and mitochondrial dysfunction resulting from the disturbance of metabolic homeostasis initiates graft inflammation. The inflammation in the short term exacerbates hepatic damage, leading to graft dysfunction and a higher incidence of acute rejection. The subsequent changes in the graft immune environment due to hepatic IRI may result in chronic rejection, cancer recurrence and fibrogenesis in the long term. In this review, we mainly focus on new mechanisms of inflammation initiated by immune activation related to metabolic alteration in the short term during liver IRI. The latest mechanisms of cancer recurrence and fibrogenesis due to the long-term impact of inflammation in hepatic IRI is also discussed. Furthermore, the development of therapeutic strategies, including ischemia preconditioning, pharmacological inhibitors and machine perfusion, for both attenuating acute inflammatory injury and preventing late-phase disease recurrence, will be summarized in the context of clinical, translational and basic research.

Laparoscopic application of the hooking technique for ultrasound-guided minimally invasive liver surgery

Laparoscopic liver surgery has a wide diffusion worldwide, but the reproducibility of a parenchyma-sparing approach with a minimally invasive technique is still to explore. Intraoperative ultrasound (IOUS) is a mandatory tool to guarantee safety (transection plane) and oncological adequacy (margin) of minor but complex resections for deep-located tumors. The hooking technique has been developed exactly with this aim: once a vessel is isolated and encircled, the surgeon applies gentle traction on the tape surrounding the vessel and, under IOUS vision, "recognizes" the vessel and the adequate level of section. At present, advanced IOUS-guided maneuvers have limited application to laparoscopic liver surgery. We report the first application of the hooking maneuver during laparoscopic hepatectomy in three consecutive patients. In all cases, it was successfully performed and allowed to section the proper vessel at the right level. No procedure-related complications occurred and no ischemic areas of the remnant liver were evident. All resections had a negative surgical margin. Even if technically demanding, the laparoscopic hooking technique is a further step toward the standardization of a minimally invasive approach to advanced parenchyma-sparing liver surgery.

Indocyanine green staining for intraoperative perfusion assessment

Indocyanine green (ICG) is a fluorescent iodide-based dye which is used in hepatic surgery to evaluate the biliary tree, liver perfusion, and function. While liver perfusion assessment and delineation of anatomic regions has been performed using ultrasound, ischemic demarcation, or indigo carmine/methylene blue staining, ICG staining can overcome limitations associated with these techniques, such as rapid washout, lack of precision, non-demarcation in damaged livers, and lack of intraparenchymal fidelity. ICG can be used to fluoresce target segments/tumors (Positive staining) or counterstain normal liver tissue leaving areas of interest unstained (negative staining). Moreover, ICG enhancement patterns vary for different tumors, such as colorectal liver metastases vs. hepatocellular carcinoma, providing not only help with detection but also assessment of differentiation. In the field of oncology, benefits of ICG include detection of small radiographically occult tumors, distinction between cirrhotic nodules and cancer, identification of necrotic tumors in chemotherapy-damaged livers, and determining margins when intraoperative ultrasound is inadequate. While ICG has important and expanding indications in hepatic surgery, limitations include small depth of penetrance, need for special monitors/equipment, and potential for dye spillage. ICG is well tolerated, has a small learning curve, minimally invasive surgical integration, and options of both portal vein and peripheral vein injection and hence is a safe and versatile method of anatomic liver mapping, tumor visualization, and liver graft perfusion evaluation in oncologic surgery and liver transplantation. Advancements in technique and technology associated with ICG will aid in increasing the indications in hepato-biliary surgery.

Exercise Training Decreases Hepatic Injury and Metastases Through Changes in Immune Response to Liver Ischemia/Reperfusion in Mice

BACKGROUND AND AIMS

Liver ischemia/reperfusion injury (IRI) induces local and systemic inflammation in which neutrophil extracellular traps (NETs) are major drivers. IRI markedly augments metastatic growth, which is consistent with the notion that the liver IRI can serve as a premetastatic niche. Exercise training (ExT) confers a sustainable protection, reducing IRI in some animal models, and has been associated with improved survival in patients with cancer; however, the impact of ExT on liver IRI or development of hepatic metastases is unknown.

APPROACH AND RESULTS

Mice were randomized into exercise (ExT) and sedentary groups before liver IRI and tumor injection. Computerized dynamic network analysis of 20 inflammatory mediators was used to dissect the sequence of mediator interactions after ischemia/reperfusion (I/R) that induce injury. ExT mice showed a significant decrease in hepatic IRI and tissue necrosis. This coincided with disassembly of complex networks among inflammatory mediators seen in sedentary mice. Neutrophil infiltration and NET formation were decreased in the ExT group, which suppressed the expression of liver endothelial cell adhesion molecules. Concurrently, ExT mice revealed a distinct population of infiltrating macrophages expressing M2 phenotypic genes. In a metastatic model, fewer metastases were present 3 weeks after I/R in the ExT mice, a finding that correlated with a marked increase in tumor-suppressing T cells within the tumor microenvironment.

CONCLUSIONS

ExT preconditioning mitigates the inflammatory response to liver IRI, protecting the liver from injury and metastases. In light of these findings, potential may exist for the reduction of liver premetastatic niches induced by liver IRI through the use of ExT as a nonpharmacologic therapy before curative surgical approaches.

Simulation of portal/hepatic vein associated remnant liver ischemia/congestion by three-dimensional visualization technology based on preoperative CT scan

Background

Remnant liver hypoperfusion is frequently observed after hepatectomy, and associated with a higher risk of postoperative complications and poorer survival. However, the development of remnant liver hypoperfusion was not fully understood.

Methods

We retrospectively analyzed patients who received hepatectomy and took contrast-enhanced computed tomography (CT) scans before, 1-week (POW1) and 4-week (POW4) after resection in our department from June 2017 to July 2019. We simulated and estimated the occurrence of portal-vein-related remnant liver ischemia (RLI) and hepatic-vein-related remnant liver congestion (RLC) after hepatectomy via three-dimensional visualization technology (3DVT) according to blood vessels ligated in the resection; then we analyzed association between the estimated RLI, RLC, and postoperative clinical outcomes.

Results

A total of 102 eligible patients were analyzed. Remnant liver hypoperfusion was observed in 47 (46%) patients in the POW1 CT scans and shrunk in the POW4 CT scans. RLC had better diagnostic significance than RLI in predicting remnant liver hypoperfusion [area under receiver operating characteristic (ROC) curve: 0.745 vs. 0.569, P=0.026]. Multivariate analysis showed that larger RLI [odds ratio (OR), 1.154; 95% confidence interval (CI), 1.075-1.240; P<0.001] was independent risk factor for post-hepatectomy liver failure (PHLF). Besides, larger RLC (OR, 1.114; 95% CI, 1.032-1.204; P=0.006) was independent risk factor for major postoperative complications.

Conclusions

Remnant liver hypoperfusion can be predicted during the preoperative surgical plan by 3DVT. Portal vein related RLI was associated with PHLF, and hepatic vein related RLC was associated with major postoperative complications. Preservation of the hepatic vein and complete removal of the perfusion territory of ligated vessels are essential procedures to reduce RLI/RLC and the risk of PHLF or other surgical complications.

Parenchymal Sparing Anatomical Liver Resections With Full Laparoscopic Approach: Description of Technique and Short-term Results

OBJECTIVE

The aim of this study was to describe laparoscopic anatomical parenchymal sparing liver resections for hepatocellular carcinoma (HCC) and colorectal liver metastases (CRLM) and report the short-term outcomes.

BACKGROUND

Anatomical resections (ARs) have better oncological outcomes compared to partial resections in patients with HCC, and some suggest should be performed also for CRLM as micrometastasis occurs through the intrahepatic structures. Furthermore, remnant liver ischemia after partial resections has been associated with worse oncological outcomes. Few experiences on laparoscopic anatomical resections have been reported and no data on limited AR exist.

METHODS

We performed a retrospective analysis of 86 patients undergoing full laparoscopic anatomical parenchymal sparing resections with preoperative surgical simulation and standardized procedures.

RESULTS

A total of 55 patients had HCC, whereas 31 had CRLM with a median of 1 lesion and a size of 30 mm. During preoperative three-dimensional (3D) simulation, a median resection volume of 120 mL was planned. Sixteen anatomical subsegmentectomies, 56 segmentectomies, and 14 sectionectomies were performed. Concordance between preoperative 3D simulation and intraoperative resection was 98.7%. Two patients were converted, and 7 patients experienced complications. Subsegmentectomies had comparable blood loss (166 mL, P = 0.59), but longer operative time (426 min, P = 0.01) than segmentectomies (blood loss 222 mL; operative time 355 min) and sectionectomies (blood loss 120 mL; operative time 295 min). R0 resection and margin width remained comparable among groups.

CONCLUSIONS

A precise preoperative planning and a standardized surgical technique allow to pursue the oncological quality of AR enhancing the safety of the parenchyma sparing principle, reducing surgical stress through a laparoscopic approach.

A snapshot of the 2020 conception of anatomic liver resections and their applicability on minimally invasive liver surgery. A preparatory survey for the Expert Consensus Meeting on Precision Anatomy for Minimally Invasive HBP Surgery

BACKGROUND

The main aim of this survey was to analyze how liver surgeons perform liver resections and to define their conception of anatomic procedures within the incorporation of minimally invasive liver surgery (MILS).

METHODS

The survey was distributed among liver surgeons. It mainly focused on personal experience on open and MILS, methods and landmarks, and experience on anatomic resections and Glissonean approach.

RESULTS

A total of 445 valid answers from 54 countries was obtained. Surgeons performing MILS mainly have below 10 years of experience (81.8% of responders) and one third has never done complex MILS. New techniques, including indocyanine green demarcation are marginally used (<25%). More than 60% of surgeons do not make a full exposure of hepatic veins during MILS, mainly due to the risk of injury or not considering it to be of utility. Although 88% of responders agreed with the concept of anatomic resection as the "resection along the border/watersheds of each order division identified by the portal vein flow", only 55% of surgeons have ever performed MILS Glissonean approaches.

CONCLUSIONS

Liver anatomy is not a static concept. Anatomic resections need training and precision. Standardization of complex anatomic resections by a minimally invasive approach should be encouraged.

Prognostic Impact of Pedicle Clamping during Liver Resection for Colorectal Metastases

Pedicle clamping (PC) during liver resection for colorectal metastases (CRLM) is used to reduce blood loss and allogeneic blood transfusion (ABT). The effect on long-term oncologic outcomes is still under debate. A retrospective analysis of the impact of PC on ABT-demand regarding overall (OS) and recurrence-free survival (RFS) in 336 patients undergoing curative resection for CRLM was carried out. Survival analysis was performed by both univariate and multivariate methods and propensity-score (PS) matching. PC was employed in 75 patients (22%). No increased postoperative morbidity was monitored. While the overall ABT-rate was comparable (35% vs. 37%, p = 0.786), a reduced demand for more than two ABT-units was observed (p = 0.046). PC-patients had better median OS (78 vs. 47 months, p = 0.005) and RFS (36 vs. 23 months, p = 0.006). Multivariate analysis revealed PC as an independent prognostic factor for OS (HR = 0.60; p = 0.009) and RFS (HR = 0.67; p = 0.017). For PC-patients, 1:2 PS-matching (N = 174) showed no differences in the overall ABT-rate compared to no-PC-patients (35% vs. 40%, p = 0.619), but a trend towards reduced transfusion requirement (>2 ABT-units: 9% vs. 21%, p = 0.052; >4 ABT-units: 2% vs. 11%, p = 0.037) and better survival (OS: 78 vs. 44 months, p = 0.088; RFS: 36 vs. 24 months; p = 0.029). Favorable long-term outcomes and lower rates of increased transfusion demand were observed in patients with PC undergoing resection for CRLM. Further prospective evaluation of potential oncologic benefits of PC in these patients may be meaningful.

Venous outflow congestion is related to poor recurrence-free survival of living donor liver transplantation recipients with hepatocellular carcinoma - a retrospective study

This study analyzed the impact of venous outflow congestion in the liver graft on hepatocellular carcinoma recurrence in liver transplantation recipients. Hepatocellular carcinoma patients who underwent living donor liver transplantation at Samsung Medical Center between 2007 and 2018 were included. The congested volume was calculated based on 2-week post-transplantation computed tomography. Recurrence-free survival and overall survival were analyzed using the multivariable Cox proportional hazard model including the degree of venous congestion. A total of 582 patients were included. There were 232 patients (39.9%) with certain degree of congestion volume. Kaplan-Meier survival analyses showed 1-, 5-, and 10-year recurrence-free survivals of 86.0%, 72.2%, and 70.7%, respectively, and overall survivals of 91.5%, 73.4%, and 68.9%, respectively. While congestion volume per 10 cm³ was a significant risk factor for recurrence-free survival (HR = 1.024, CI: 1.002-1.047, P = 0.034), there was no significant relationship with overall survival. (HR = 1.015, CI: 0.992-1.039, P = 0.213). Venous outflow congestion in the liver after living donor liver transplantation was related to the poor recurrence-free survival of hepatocellular carcinoma patients.

Myeloid tumor necrosis factor and heme oxygenase-1 regulate the progression of colorectal liver metastases during hepatic ischemia-reperfusion

The liver ischemia-reperfusion (IR) injury that occurs consequently to hepatic resection performed in patients with metastases can lead to tumor relapse for not fully understood reasons. We assessed the effects of liver IR on tumor growth and the innate immune response in a mouse model of colorectal (CR) liver metastasis. Mice subjected to liver ischemia 2 days after intrasplenic injection of CR carcinoma cells displayed a higher metastatic load in the liver, correlating with Kupffer cells (KC) death through the activation of receptor-interating protein 3 kinase (RIPK3) and caspase-1 and a recruitment of monocytes. Interestingly, the immunoregulatory mediators, tumor necrosis factor-α (TNF-α) and heme oxygenase-1 (HO-1) were strongly upregulated in recruited monocytes and were also expressed in the surviving KC following IR. Using TNF^flox/flox LysM^cre/wt mice, we showed that TNF deficiency in macrophages and monocytes favors tumor progression after IR. The antitumor effect of myeloid cell-derived TNF involved direct tumor cell apoptosis and a reduced expression of immunosuppressive molecules such as transforming growth factor-β, interleukin (IL)-10, inducible nitric oxyde synthase (iNOS), IL-33 and HO-1. Conversely, a monocyte/macrophage-specific deficiency in HO-1 (HO-1^flox/flox LysM^cre/wt ) or the blockade of HO-1 function led to the control of tumor progression post-liver IR. Importantly, host cell RIPK3 deficiency maintains the KC number upon IR, inhibits the IR-induced innate cell recruitment, increases the TNF level, decreases the HO-1 level and suppresses the tumor outgrowth. In conclusion, tumor recurrence in host undergoing liver IR is associated with the death of antitumoral KC and the recruitment of monocytes endowed with immunosuppressive properties. In both of which HO-1 inhibition would reinforce their antitumoral activity.

Re-evaluation of the Couinaud classification for segmental anatomy of the right liver, with particular attention to the relevance of cranio-caudal boundaries

BACKGROUND

Although the Couinaud classification of liver segments has been challenged by several studies, whether the cranio-caudal boundaries can be delineated in the right liver has not yet been assessed. This study scrutinized the third-order branching pattern of the portal vein in the right liver with attention to the validity of cranio-caudal segmentation.

METHODS

Three-dimensional reconstruction of the portal vein and hepatic vein, using non-contrast-enhanced magnetic resonance imaging was performed in 50 healthy participants.

RESULTS

In the right paramedian sector, the portal vein ramified into 2 thick P8s (P8vent and P8dor) in all the participants. Additional thick P8s that ran laterally and/or medially (P8lat and/or P8med) were observed in 18 (32%) participants. In contrast, multiple thin P5s, ranging in number from 2 to 6 (median, 4), branched from the right paramedian trunk, the right portal trunk, and/or even from P8s. In the right lateral sector, an arch-like type in which multiple P6s ramified from a single thick P7 was observed in 26 (52%) participants. A bifurcation type composed of a single P7 and a single P6 was observed in 23 (46%) participants, and a trifurcation type was observed in 1 participant.

CONCLUSION

No clear cranio-caudal intersegmental plane could be delineated in the right liver in most of the participants. The resection of a whole Couinaud segment in the right liver should not be regarded as a systematic, anatomic resection from an oncologic viewpoint. In contrast, detailed information on the third-order portal vein ramification pattern is likely to be helpful when performing smaller anatomic resections.

Demarcation Line Assessment in Anatomical Liver Resection: An Overview

Anatomical liver resection (ALR) is the preferred oncological approach for the treatment of primary liver malignancies, such as hepatocellular carcinoma and intrahepatic cholangiocarcinoma. The demarcation line (DL) is formed by means of selective vascular occlusion and is used by surgeons to guide ALR. Emerging intraoperative technologies are playing a major role to enhance the surgeon’s vision and ensure a precise oncologic surgery. In this article, a brief overview of modalities to assess the DL during ALRs is presented, from the established conventional techniques to future perspectives.

Short-term Outcomes of "Difficult" Laparoscopic Liver Resection at Specialized Centers: Report From INSTALL (International Survey on Technical Aspects of Laparoscopic Liver Resection)-2 on 4478 Patients

OBJECTIVE

To define the current status of "difficult" LLR, a global database was created and investigated.

BACKGROUND

In the Second International Consensus Conference in 2014, minor LLR was considered as a standard practice and major LLR remained an innovative procedure. Since then, no updates on worldwide trends have been available.

METHODS

A questionnaire on all consecutive patients who underwent difficult LLR (major hepatectomy, posterosuperior segmentectomy, sectionectomy, living donor hepatectomy, tumor size ≥10 cm, Child-Pugh grade ≥B, combined with biliary reconstruction, and Iwate criteria difficulty score ≥7) in 2014-2018 was distributed via email to 65 high-volume LLR centers worldwide. Individual data on patient and tumor demographics, surgical information, and short-term outcomes were obtained to create a large-scale international registry for analyses.

RESULTS

Overall, 58 centers in 19 countries performed 4478 difficult LLR (median, 58.5; range, 5-418) during the study period. Hepatocellular carcinoma accounted for ≥40% of all indications. Half of the patients underwent major hepatectomy, followed by sectionectomy, posterosuperior segmentectomy, and living donor hepatectomy. In the vast majority of procedures, Clavien-Dindo grade ≥IIIa complication rates of ≈10% and 90-day mortality rates of ≈1% were achieved. Left or right trisectionectomy had the worst Clavien-Dindo grade ≥IIIa complication rate of ≥10% and 90-day mortality rate of 5%-10%. No significant correlation was observed between center volume and short-term outcomes.

CONCLUSIONS

Total 4478 patients underwent difficult LLR worldwide in 2014-2018. Most procedures are safe and feasible when conducted in specialized centers.

Platelet recovery correlates parenchymal volume recovery after liver resection

AIM

Platelet count seems to assess liver function and predict liver regeneration, but factors associated with liver regeneration remain unclear. This study analyzed the relationship between platelet recovery and postresection liver regeneration.

METHODS

Data from 343 candidates from 1245 consecutive patients with liver resection of more than Couinaud's segments were analyzed. Patients were divided into a low-platelet-recovery rate (LPRR) group (lowest 25%) or a control group on the basis of the platelet recovery rate on postoperative day (POD)7. Data were matched before analysis to adjust for operation scale. Trends in liver functional recovery were assessed, and liver volume recovery and remnant ischemic area was calculated using computed tomography volumetry. Factors predicting liver regeneration were analyzed.

RESULTS

In 78 matched-pair patients, the all-complications rate (42.3% vs. 26.9%, P = 0.002) and infectious complications rate (21.8% vs. 9.0%, P = 0.027) were significantly higher in the LPRR group than in controls. Trends in liver functional recovery did not differ significantly, whereas significant differences remained for platelet recovery. Parenchyma volume recovery was delayed in the LPRR group from POD7 (84.5% vs. 78.1, P < 0.01) to POD30 (92.5% vs. 85.6, P < 0.01). Platelet recovery rate on POD7 correlated negatively with ischemic liver volume as evaluated on POD2 by computed tomography (r = 0.691). Postoperative ischemic volume on POD2 (5.41 [1.98-11.21], P < 0.001), infectious complications (3.48 [1.44-7.37], P < 0.001), and multiple resection (1.67 [1.10-4.11], P = 0.011) predicted delayed platelet recovery rate on multivariate analysis.

CONCLUSION

Platelet recovery correlated with liver volume recovery and occurrence of complications. Large ischemic area might negatively impact regeneration after liver resection.

Laparoscopic Parenchymal-Sparing Hepatectomy for Multiple Colorectal Liver Metastases Improves Outcomes and Salvageability: A Propensity Score-Matched Analysis

BACKGROUND

Parenchymal-sparing hepatectomy (PSH) is regarded as the standard of care for colorectal liver metastases (CRLMs) in open surgery. However, the surgical and oncological benefits of laparoscopic PSH compared with laparoscopic major hepatectomy (MH) have not been fully documented.

METHODS

A total of 269 patients who underwent initial laparoscopic liver resections with curative intent for CRLMs between 2004 and 2017 were enrolled. Preoperative patient characteristics and tumor burden were adjusted with propensity score matching, and laparoscopic PSH was compared with laparoscopic MH after matching.

RESULTS

PSH was performed in 148 patients, while MH was performed in 121 patients. After propensity score matching, 82 PSH and 82 MH patients showed similar preoperative characteristics. PSH was associated with lower rates of major postoperative complications compared with MH (6.1 vs. 15.9%; p = 0.046). Recurrence-free survival (RFS) and liver-specific RFS rates were comparable between both groups (p = 0.595 and 0.683). Repeat hepatectomy for liver recurrence was more frequently performed in the PSH group (63.9 vs. 36.4%; p = 0.022), and the PSH group also showed a trend toward a higher overall survival (OS) rate (5-year OS 79.4 vs. 64.3%; p = 0.067). Multivariate analyses revealed that initial MH was one of the risk factors to preclude repeat hepatectomy after liver recurrence (hazard ratio 2.39, p = 0.047).

CONCLUSIONS

Laparoscopic PSH provided surgical and oncological benefits for CRLMs, with less complications, similar recurrence rates, and increased salvageability through repeat hepatectomy, compared with laparoscopic MH. PSH should be the standard approach, even in laparoscopic procedures.

A systematic review and meta-analysis comparing the short- and long-term outcomes for laparoscopic and open liver resections for liver metastases from colorectal cancer

BACKGROUND

The laparoscopic approach to liver resection has experienced exponential growth in recent years. However, evidence-based guidelines are needed for its safe future progression. The main aim of our study was to perform a systematic review and meta-analysis comparing the short- and long-term outcomes of laparoscopic and open liver resections for colorectal liver metastases (CRLM).

METHODS

To identify all the comparative manuscripts between laparoscopic and open liver resections for CRLM, all published English language studies with more than ten cases were screened. In addition to the primary meta-analysis, 3 specific subgroup analyses were performed on patients undergoing minor-only, major-only and synchronous resections. The quality of the studies was assessed using the Scottish Intercollegiate Guidelines Network (SIGN) methodology and Newcastle-Ottawa Score.

RESULTS

From the initial 194 manuscripts identified, 21 were meta-analysed, including results from the first randomized trial comparing open and laparoscopic resections of CRLM. Five of these were specific to patients undergoing a synchronous resection (399 cases), while six focused on minor (3 series including 226 cases) and major (3 series including 135 cases) resections, respectively. Thirteen manuscripts compared 2543 cases but could not be assigned to any of the above sub-analyses, so were analysed independently. The majority of short-term outcomes were favourable to the laparoscopic approach with equivalent rates of negative resection margins. No differences were observed between the approaches in overall or disease-free survival at 1, 3 or 5 years.

CONCLUSION

Laparoscopic liver resection for CRLM offers improved short-term outcomes with comparable long-term outcomes when compared to open approach.

Anatomy of the Right Anterior Sector of the Liver and Its Clinical Implications in Surgery

BACKGROUND

Surgery remains the gold standard both for delimited hepatocellular carcinoma by selective anatomic liver segentectomy and for colorectal liver metastases by parenchymal sparing liver resection. Right anterior sector (RAS) (segments V-VIII; Couinaud) is the largest and most difficult sector to operate on. A better knowledge of its segmentation could prevent postoperative remnant liver ischemia and its impacts on patient's survival.

METHODS

A literature search was conducted in PubMed for papers on anatomy and surgery of the right anterior sector.

RESULTS

Segmentation of the RAS depended of the anatomic variations of the third-order portal branches. Cranio-caudal segmentation was the most commonly found (50-53%), followed by ventro-dorsal (23-26%), trifurcation (13-20%), and quadrifurcation types (5-11%). Ventral and dorsal partial or total subsegmentectomy seemed accessible in 47 to 50% of patients, including bifurcation, trifurcation, and quadrifurcation types, and could spare up to 22% of the total liver volume. The RAS hepatic vein was present in 85-100% of the patients and could be used as a landmark between RAS dorsal and ventral part in 63% of patients. Reported overall morbidity rate of RAS subsegmentectomy ranged from 33 to 59% among studies with a postoperative major complication rate (Clavien-Dindo ≥ III) ranging around 18% and a biliary leakage rate from 16 to 21%. In-hospital reported mortality rate was low (0-3%), and results were comparable to "classic" liver resections. RAS subsegmentectomy remains a complex procedure; median operating time ranged from 253 to 520 min and median intraoperative blood loss reached 1255 ml.

CONCLUSION

Better knowledge of RAS anatomy could allow for parenchymal preservation by using subsegmentectomy of the RAS, selective or as a part of a major hepatectomy.