Early Outcomes of Extended Hepatectomy: An Experience from the University Hospital of Nepal

Background Extended hepatectomy (≥ 5 liver segments resection) may be required to have a complete surgical resection and provide the best chance of cure of hepatobiliary tumors. It is associated with high morbidity and mortality but with good perioperative care, its outcomes can be improved. This study was conducted to evaluate the early outcomes of extended hepatectomy at a university hospital in Nepal. Methods For this study, prospectively collected data from all patients who underwent extended hepatectomy from October 2012 to April 2022 were reviewed and analyzed retrospectively. Demographic data, liver volume augmentation methods used, intraoperative variables, and postoperative complications were analyzed. Results Seventeen patients underwent extended hepatectomy from October 2012 to April 2022. Among them 11 (64.7%) were female and the mean age was 53.9 ±16.3 years (18-72 years). Right extended hepatectomy was the most commonly performed procedure (n = 15, 88.2%), and left extended hepatectomy was performed in the remaining (n = 2, 11.8%). Six patients underwent liver volume augmentation procedures (35.3%) with portal vein embolization (PVE) in three, portal vein ligation (PVL) in one, and partial associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) in two patients. Overall complications were 70% with major complications (Clavien Dindo ≥ IIIa) constituting 35.3%. The most common hepatectomy-specific complication was post-hepatectomy liver failure (PHLF) in six cases. The 30-day mortality was 17.6% (three patients). Conclusion Extended hepatectomy can be performed with acceptable major complications and mortality rates in selected patients.

Gut microbiome dysbiosis in patients with hepatitis B virus-related hepatocellular carcinoma after extended hepatectomy liver failure

Background

Hepatitis B virus-related hepatocellular carcinoma (B-HCC) negatively affects the gut microbiome. This study aimed to investigate the gut microbiome profiles and functions post-hepatectomy liver failure (PHLF) after extended hepatectomy (e-PHLF) to obtain valuable insights, identify potential diagnostic biomarkers, and assist in the treatment of this disease.

Methods

B-HCC patients who underwent extended hepatectomy were consecutively recruited and divided into Group A (n=15) and Group B (n=15) based on the presence and absence of e-PHLF, respectively. The relationships between gut microbiota and extended hepatectomy liver failure were explored using 16S ribosomal RNA (16S rRNA) gene sequencing data.

Results

Following extended hepatectomy, the α-diversity of Group A was significantly higher than that of Group B (Shannon P=0.034 or Simpson P=0.031), and the β-diversity differed significantly between Groups A and B (P=0.004, R=0.100). At the genus level, 10 bacterial genera (Bacteroides, Pantoea, Methylobacterium-Methylorubrum, Inquilinus, Mycobacterium, Allisonella, Helicobacter, GCA-900066575, IS-44, and Faecalibacterium) were significantly enriched in Group A, whereas five genera (Papillibacter, Scardovia, Turicibacter, Catabacter, and Senegalimassilia) were significantly enriched in Group B. The highly abundant genera Bacteroides, Pantoea, Faecalibacterium, and Turicibacter participated in multiple amino acid metabolism pathways, organic acid metabolism pathways, pyrimidine metabolism pathways, palmitate biosynthesis, and stearate biosynthesis. Redundancy analysis showed that four environmental factors (total bilirubin, international normalized ratio, prealbumin, and albumin) were significantly correlated with intestinal microorganisms. The formation of interaction networks between different gut microbiomes revealed important correlations between the gut microbiome, and there was a significant correlation between the highly abundant gut microbiome and main functions.

Conclusions

The gut microbiota characteristics in B-HCC patients after extended hepatectomy liver failure might allow for the use of non-invasive biomarkers for disease diagnosis and treatment.

Critical Role of LSEC in Post-Hepatectomy Liver Regeneration and Failure

Liver sinusoids are lined by liver sinusoidal endothelial cells (LSEC), which represent approximately 15 to 20% of the liver cells, but only 3% of the total liver volume. LSEC have unique functions, such as fluid filtration, blood vessel tone modulation, blood clotting, inflammatory cell recruitment, and metabolite and hormone trafficking. Different subtypes of liver endothelial cells are also known to control liver zonation and hepatocyte function. Here, we have reviewed the origin of LSEC, the different subtypes identified in the liver, as well as their renewal during homeostasis. The liver has the exceptional ability to regenerate from small remnants. The past decades have seen increasing awareness in the role of non-parenchymal cells in liver regeneration despite not being the most represented population. While a lot of knowledge has emerged, clarification is needed regarding the role of LSEC in sensing shear stress and on their participation in the inductive phase of regeneration by priming the hepatocytes and delivering mitogenic factors. It is also unclear if bone marrow-derived LSEC participate in the proliferative phase of liver regeneration. Similarly, data are scarce as to LSEC having a role in the termination phase of the regeneration process. Here, we review what is known about the interaction between LSEC and other liver cells during the different phases of liver regeneration. We next explain extended hepatectomy and small liver transplantation, which lead to "small for size syndrome" (SFSS), a lethal liver failure. SFSS is linked to endothelial denudation, necrosis, and lobular disturbance. Using the knowledge learned from partial hepatectomy studies on LSEC, we expose several techniques that are, or could be, used to avoid the "small for size syndrome" after extended hepatectomy or small liver transplantation.

The Modulating Effect of Ursodeoxycholic Acid on Liver Tissue Cyclooxygenase-2 Expression Following Extended Hepatectomy

Introduction: Hepatic regeneration is a complex process involving a multitude of well-timed molecular operations. Ursodeoxycholic acid (UDCA) is postulated to exert a protective effect against oxidative stress and enzymatic degradation of the extracellular matrix, in turn potentiating the regenerative response. The aim of the present animal study is to evaluate the impact of UDCA administration in liver tissue expression of cyclooxygenase-2 (COX-2) in a setting of acute liver failure achieved by 80% hepatectomy.

Materials and methods: Twenty-four adult male Sprague-Dawley rats were randomly assigned to an experimental (UDCA) and a control group. Animals in the UDCA received oral pretreatment with UDCA for 14 days via feeding tube, while animals in the control group received saline. All animals underwent resection of approximately 80% of the liver parenchyma. Tissue and blood sample collection were performed 48 hours postoperatively.

Results: The postoperative mitotic index and Ki-67 levels were found to be elevated in the UDCA group (43±11.4 and 13.7±24.7 versus 31±16.7 and 7.6±5.7), albeit without any statistical significance. Pretreatment with UDCA significantly decreased COX-2 expression levels (p=0.28) as well as serum tumor necrosis factor α (TNFα) levels (37.3±10.9 pg/mL versus 75.4±14.4 pg/mL, p=0.004). COX-2 expression score was observed to be weakly correlated to Ki-67 levels in both groups. Although COX-2 expression score was not correlated with serum TNFα levels in the control group, animals pretreated with UDCA exhibited moderate correlation (r=0.45).

Conclusion: Preoperative administration of UDCA exerts a suppressive effect on tissue expression of COX-2 following 80% hepatectomy and enforces a positive correlation between COX-2 and serum TNFα levels, suggesting that UDCA preconditions liver tissue to display an enhanced regenerative response to circulating cytokines, most notably TNFα. The weak association of COX-2 with Ki-67 expression levels suggests that COX-2 may be of secondary importance during the early phases of liver regeneration.

A fast and easy-to-learn technique for liver resection in a porcine model

Objective

Despite the recent advances in surgical techniques and perioperative care, liver resection (especially extended hepatectomy) is still a high-risk procedure with considerable morbidity and mortality. Experimental large animal models are the best option for studies in this regard. The present study was performed to present an easy-to-learn, fast, and multipurpose model of liver resection in a porcine model.

Method

Stepwise liver resections (resection of segments II/III, IVa/IVb, and VIII/IV) were performed in eight pigs with intraoperative monitoring of hemodynamic parameters. The technical aspects, tips, and tricks of this method are explained in detail.

Results

Based on the specific anatomical characteristics of the porcine liver, all resection types including segmental resection, hemihepatectomy, and extended hepatectomy could be performed in one animal in an easy-to-learn and fast technique. All animals were hemodynamically stable following stepwise liver resection.

Conclusion

Stepwise liver resection using stapler in a porcine model is a fast and easy-to-learn method with which junior staff and research fellows can perform liver resection up to extended hepatectomy under stable conditions.

The Effects of Ursodeoxycholic Acid Pretreatment in an Experimental Setting of Extended Hepatectomy: A Feasibility Study

Introduction Liver regeneration is an exceptionally complex process, orchestrated by a multitude of growth factors and cytokines. Tumor necrosis factor-alpha (TNF-a) and interleukin-6 (Il-6) have a pivotal role in the initiation of the regenerative response. Ursodeoxycholic acid (UDCA) exhibits a liver protective effect that enhances liver growth after injury. The aim of the present study is to evaluate the effect of UDCA in the circulating levels of TNF-a and Il-6 in rats undergoing extended 80% hepatectomy. Materials and methods Twenty-two male Sprague Dawley rats were randomly assigned in an experimental (UDCA group) and a control group. Mice in the UDCA-group received oral pretreatment of UDCA for two weeks preoperatively at a dosage of 25 mg/kg/day. An 80% hepatic resection was performed in both groups by resecting the middle, inferior right, and left lateral liver lobes. The experiment ended 48 hours postoperatively. Results UDCA pretreatment significantly depressed circulating levels of both TNF-a and Il-6 after the conclusion of the experiment as compared to the control group (p=0.001 and p=0.01, respectively). Furthermore, TNF-a levels were significantly reduced before the institution of liver injury (p=0.02). Mice in the UDCA-group exhibited better liver growth as demonstrated by significantly increased Ki-67 and mitotic rate (p=0.04 and p=0.02, respectively). Finally, the liver regeneration rate (LRR) was significantly elevated in the experimental group (UDCA group, 54.5% vs control group, 35.8%; p=0.002) signifying enhanced liver growth kinetics. Conclusion UDCA reduces the expression of TNF-a and Il-6 during the priming phase of liver regeneration. An 80% hepatectomy model of acute liver failure exhibited enhanced liver regeneration in the experimental group, plausibly due to the immunomodulatory effects of UDCA.

Fifty-year history of biliary surgery

There has been enormous progress in the surgical treatment of biliary tract cancers in the past 50 years. In preoperative management, biliary drainage methods have changed from percutaneous transhepatic biliary drainage to endoscopic nasobiliary drainage, while the advent of multidetector-row computed tomography in imaging diagnostics now enables visualization of three-dimensional anatomy, extent of cancer progression, and hepatic segment volume. Portal vein embolization has also greatly improved the safety of extended hepatectomy, and indication of extended hepatectomy can now be objectively determined with a combination of the indocyanine green test and computed tomography volumetry. In terms of surgery, combined resection and reconstruction of the portal vein and/or hepatic artery can now be safely carried out at specialized centers. Further, long-term survival can be attained with combined vascular resection if R0 resection can be achieved, even in locally advanced cancer. Hepatopancreatoduodenectomy, combined major hepatectomy with pancreatoduodenectomy, should be aggressively carried out for laterally advanced cholangiocarcinoma, whereas its indication for advanced gallbladder cancer should be carefully evaluated. Japanese surgeons have made a significant contribution to the progression of extended surgeries such as combined vascular resection and hepatopancreatoduodenectomy for biliary tract cancer.

Discrepancy between volume and functional recovery in early phase liver regeneration following extended hepatectomy with extrahepatic bile duct resection

AIM

To elucidate the clinical factors having an impact on liver regeneration rate following preoperative portal vein embolization (PVE) and subsequent extended hepatectomy. The correlation between liver volume and functional recovery after extended hepatectomy was also investigated.

METHODS

Records of patients who underwent extended hepatectomy with extrahepatic bile duct resection following PVE for perihilar cholangiocarcinoma were reviewed retrospectively with attention to liver regeneration. All patients underwent computed tomography before PVE, after PVE (immediately before surgery), and on postoperative day (POD) 7. The kinetic growth rate (KGR) was calculated as the percent increase in liver volume relative to the future liver remnant volume per day after PVE (KGR_PVE ) and after POD 7 (KGR_POD7 ) using the computed tomography images before PVE, after PVE, and on POD 7.

RESULTS

In the 289 study patients, the median of KGR_PVE was 1.35%/day whereas that of KGR_POD7 was 5.56%/day. The extent of liver resection had the greatest impact on both KGR_PVE and KGR_POD7 and the impacts of other factors were less. There was a significant negative correlation between KGR_PVE and KGR_POD7 (P = 0.002). No correlations were observed between KGR_PVE or KGR_POD7 and serum total bilirubin and prothrombin time - international normalized ratio on POD 7, nor in the incidence of liver failure after surgery.

CONCLUSIONS

Early phase liver regeneration after extended hepatectomy was largely influenced by the extent of liver resection and showed no correlation with the indices of liver failure. There was a discrepancy between volume and functional recovery in early phase liver regeneration.

Liver-Selective MMP-9 Inhibition in the Rat Eliminates Ischemia-Reperfusion Injury and Accelerates Liver Regeneration

Recruitment of liver sinusoidal endothelial cell progenitor cells (sprocs) from the bone marrow by vascular endothelial growth factor-stromal cell-derived factor-1 (VEGF-sdf-1) signaling promotes recovery from injury and drives liver regeneration. Matrix metalloproteinases (MMPs) can proteolytically cleave VEGF, which might inhibit progenitor cell recruitment, but systemic matrix metalloproteinase inhibition might prevent efflux of progenitors from the bone marrow. The hypothesis for this study was that liver-selective MMP-9 inhibition would protect the hepatic VEGF-sdf-1 signaling pathway, enhance bone marrow sproc recruitment, and thereby ameliorate liver injury and accelerate liver regeneration, whereas systemic MMP inhibition would impair bone marrow sproc mobilization and therefore have less benefit or be detrimental. We found that liver-selective MMP-9 inhibition accelerated liver regeneration after partial hepatectomy by 40%, whereas systemic MMP inhibition impaired liver regeneration. Liver-selective MMP-9 inhibition largely abolished warm ischemia-reperfusion injury. In the extended hepatectomy model, liver-selective MMP-9 inhibition restored liver sinusoidal endothelial cell integrity, enhanced liver regeneration, and reduced ascites. Liver-selective MMP-9 inhibition markedly increased recruitment and engraftment of bone marrow sprocs, whereas systemic MMP inhibition impaired mobilization of bone marrow sprocs and their hepatic engraftment. Hepatic MMP-9 proteolytically cleaved VEGF after partial hepatectomy. Liver-selective MMP-9 inhibition prevented VEGF cleavage and doubled protein expression of VEGF and its downstream signaling partner sdf-1. In contrast, systemic MMP inhibition enhanced recruitment and engraftment of infused allogeneic progenitors. Conclusion: Liver-selective MMP inhibition prevents proteolytic cleavage of hepatic VEGF, which enhances recruitment and engraftment of bone marrow sprocs after liver injury. This ameliorates injury and accelerates liver regeneration. Liver-selective MMP-9 inhibition may be a therapeutic tool for liver injury that damages the vasculature, whereas systemic MMP inhibition can enhance the benefit of stem cell therapy with endothelial progenitor cells.

Successful Management of an "Unresectable" Intrahepatic Cholangiocarcinoma with Neoadjuvant Systemic Therapy, Chemoembolization, and Extended Hepatectomy with Portal Vein Reconstruction

Cholangiocarcinoma is a rare, but invariably fatal primary hepatic tumor that is often diagnosed at advanced stages with minimal options of surgical cure. Relatively few patients diagnosed with cholangiocarcinoma are considered surgical candidates, owing to the extent of the disease at presentation, the presence of vascular invasion or extrahepatic disease, and/or poor functional status with advanced age being most commonly associated. There is no clear consensus for the management of advanced cholangiocarcinomas, as the current literature is typically based on limited patient numbers and anecdotal experiences at best. This case report represents the successful management of a large, advanced intrahepatic cholangiocarcinoma using multiple treatment modalities including systemic chemotherapy, liver-directed therapy, portal vein embolization, and extended hepatectomy with portal vein resection and reconstruction.

Present status and future perspectives of ALPPS (associating liver partition and portal vein ligation for staged hepatectomy)

First International Consensus Meeting, Hamburg, Germany, 27-28 February 2015 More than 160 participants took part in the conference for 2 days. A total of 58 world renown experts on ALPPS (associating liver partition and portal vein ligation for staged hepatectomy) were invited from all over the world. The faculty was divided into many different subgroups that were in contact during the 2-3 months before the conference analyzing all the most important aspects of this technique and summarizing it in a common structured work to be presented during the congress, giving final recommendations in the form of bulleted point statements. The aim was to gain a solid basis of preliminary agreement on many controversial aspects of ALPPS. A poster area was also organized with 35 posters reporting mostly mono-institutional experiences on single aspects of the technique from all five continents.

Greater complexity of liver surgery is not associated with an increased incidence of liver-related complications except for bile leak: an experience with 2,628 consecutive resections

BACKGROUND

Advances in technique, technology, and perioperative care have allowed for the more frequent performance of complex and extended hepatic resections. The purpose of this study was to determine if this increasing complexity has been accompanied by a rise in liver-related complications.

METHODS

A large prospective single-institution database of patients who underwent hepatic resection was used to identify the incidence of liver-related complications. Liver resections were divided into an early era and a late era with equal number of patients (surgery performed before or after 18 May 2006). Patient characteristics and perioperative factors were compared between the two groups.

RESULTS

Between 1997 and 2011, 2,628 hepatic resections were performed, with a 90-day morbidity and mortality rate of 37 and 2 %, respectively. We identified higher rates of repeat hepatectomy (12.2 vs 6.1 %; p < 0.001), two-stage resection (4.0 vs 1 %; p < 0.001), extended right hepatectomy (17.6 vs 14.6 %; p = 0.04), and preoperative portal vein embolization (9.1 vs 5.9 %; p < 0.001) in the late era. The incidence of perihepatic abscess (3.7 vs 2.1 %; p = 0.02) and hemorrhage (0.9 vs 0.3 %; p = 0.045) decreased in the late era and the incidence of hepatic insufficiency (3.1 vs 2.6 %; p = 0.41) remained stable. In contrast, the rate of bile leak increased (5.9 vs 3.7 %; p = 0.011). Independent predictors of bile leak included bile duct resection, extended hepatectomy, repeat hepatectomy, en bloc diaphragmatic resection, and intraoperative transfusion.

CONCLUSIONS

The complexity of liver surgery has increased over time, with a concomitant increase in bile leak rate. Given the strong association between bile leak and other poor outcomes, the development of novel technical strategies to reduce bile leaks is indicated.

Effect of cold ischemia/reperfusion injury and/or shear stress with portal hypertension on the expression of matrix metalloproteinase-9

BACKGROUND

Matrix metalloproteinase (MMP)-9 plays an important role in liver regeneration after liver surgery. MMP-9 behavior is complicated in cold ischemia/warm reperfusion injury (CIWRI) and/or shear stress with portal hypertension. Small-for-size grafts (SFSGs) are also an issue.

MATERIALS AND METHODS

We used a rat model to examine MMP-9 expression 6 h after laparotomy, a temporal clamp (Pringle maneuver), orthotopic liver transplantation (OLT) with a whole-liver graft (100% OLT), partial hepatectomy without the Pringle maneuver (60% hepatectomy) and split orthotopic liver transplantation (SOLT) with a SFSG (40% SOLT) were investigated. Four liver samples were collected in each group.

RESULTS

The normalized ratio of MMP-9 was not significantly different with a temporal clamp (P = 0.1963), 100% OLT (P = 0.1781) and 60% hepatectomy (P = 0.2367), but it was significantly higher with 40% SOLT compared to that with laparotomy (P = 0.0159).

CONCLUSION

Forty percent SOLT is accompanied by not only CIWRI but also shear stress. This fatal damage results in increased MMP-9 expression.