Portal Vein Embolization Reduces Postoperative Hepatic Insufficiency Associated with Postchemotherapy Hepatic Atrophy

Propensity Score-Matched Analysis of Liver Venous Deprivation and Portal Vein Embolization Before Planned Hepatectomy in Patients with Extensive Colorectal Liver Metastases and High-Risk Factors for Inadequate Regeneration

BACKGROUND

Liver venous deprivation (LVD) is known to induce better future liver remnant (FLR) hypertrophy than portal vein embolization (PVE). The role of LVD, compared with PVE, in inducing FLR hypertrophy and allowing safe hepatectomy for patients with extensive colorectal liver metastases (CLM) and high-risk factors for inadequate hypertrophy remains unclear.

METHODS

Patients undergoing LVD (n = 22) were matched to patients undergoing PVE (n = 279) in a 1:3 ratio based on propensity scores, prior to planned hepatectomy for CLM at a single center (1998-2023). The propensity scores accounted for high-risk factors for inadequate hypertrophy, namely pre-procedure standardized FLR (sFLR), body mass index, number of systemic therapy cycles, an extension of PVE to segment IV portal vein branches, prior resection, and chemotherapy-associated liver injury.

RESULTS

The matched cohort included 78 patients (LVD, n = 22; PVE, n = 56). Baseline characteristics were comparable. The number of tumors in the whole liver was similar but more LVD patients had five or more tumors in the left liver (32% vs. 11%; p = 0.024). Post-procedure sFLR was similar but LVD patients had a significantly higher degree of hypertrophy (16% vs. 11%; p = 0.017) and kinetic growth rate (3.9 vs. 2.4% per week; p = 0.006). More LVD patients underwent extended right hepatectomy (93% vs. 55%; p = 0.008). Only one patient had postoperative hepatic insufficiency after PVE, and no patients died within 90 days of hepatectomy.

CONCLUSION

In patients with extensive CLM and high-risk factors, LVD is associated with better FLR hypertrophy compared with PVE and allows for safely performing curative-intent extended major hepatectomy.

Current evidence on posthepatectomy liver failure: comprehensive review

INTRODUCTION

Despite important advances in many areas of hepatobiliary surgical practice during the past decades, posthepatectomy liver failure (PHLF) still represents an important clinical challenge for the hepatobiliary surgeon. The aim of this review is to present the current body of evidence regarding different aspects of PHLF.

METHODS

A literature review was conducted to identify relevant articles for each topic of PHLF covered in this review. The literature search was performed using Medical Subject Heading terms on PubMed for articles on PHLF in English until May 2022.

RESULTS

Uniform reporting on PHLF is lacking due to the use of various definitions in the literature. There is no consensus on optimal preoperative assessment before major hepatectomy to avoid PHLF, although many try to estimate future liver remnant function. Once PHLF occurs, there is still no effective treatment, except liver transplantation, where the reported experience is limited.

DISCUSSION

Strict adherence to one definition is advised when reporting data on PHLF. The use of the International Study Group of Liver Surgery criteria of PHLF is recommended. There is still no widespread established method for future liver remnant function assessment. Liver transplantation is currently the only effective way to treat severe, intractable PHLF, but for many indications, this treatment is not available in most countries.

Neoadjuvant chemotherapy for colorectal liver metastases: A contemporary review of the literature

Colorectal carcinoma (CRC) is one of the leading causes of cancer-related deaths worldwide, and up to 50% of patients with CRC develop colorectal liver metastases (CRLM). For these patients, surgical resection remains the only opportunity for cure and long-term survival. Over the past few decades, outcomes of patients with metastatic CRC have improved significantly due to advances in systemic therapy, as well as improvements in operative technique and perioperative care. Chemotherapy in the modern era of oxaliplatin- and irinotecan-containing regimens has been augmented by the introduction of targeted biologics and immunotherapeutic agents. The increasing efficacy of contemporary systemic therapies has led to an expansion in the proportion of patients eligible for curative-intent surgery. Consequently, the use of neoadjuvant strategies is becoming progressively more established. For patients with CRLM, the primary advantage of neoadjuvant chemotherapy (NCT) is the potential to down-stage metastatic disease in order to facilitate hepatic resection. On the other hand, the routine use of NCT for patients with resectable metastases remains controversial, especially given the potential risk of inducing chemotherapy-associated liver injury prior to hepatectomy. Current guidelines recommend upfront surgery in patients with initially resectable disease and low operative risk, reserving NCT for patients with borderline resectable or unresectable disease and high operative risk. Patients undergoing NCT require close monitoring for tumor response and conversion of CRLM to resectability. In light of the growing number of treatment options available to patients with metastatic CRC, it is generally agreed that these patients are best served at tertiary centers with an expert multidisciplinary team.

Safety of bioabsorbable membrane (Seprafilim®) in hepatectomy in the era of aggressive liver surgery

BACKGROUND

Repeat hepatectomy has been recognized as an effective treatment for hepatic malignancies, and a sheet type adhesion barrier, Seprafilm® has increasingly been used during hepatectomy to ease future relaparotomy. However, there is not yet sufficient evidence to support the safety of use of Seprafilm in liver surgery.

METHODS

Data of 151 patients who had undergone open hepatectomy were retrospectively reviewed and the incidence of major abdominal morbidity was compared between patients in whom Seprafilm had and had not been used.

RESULTS

Seprafilm was used in 108 patients (Seprafilm group) and no adhesion barrier was used in 43 patients (comparison group). There was no significant difference in the rate of major abdominal morbidities between the two groups (Seprafilm vs. comparison: 10% vs. 16%, P = 0.403). Although the Seprafilm group showed a tendency toward increased incidence of bile leakage (7% vs. 2%), and placement of Seprafilm on the hepatoduodenal ligament or on the visceral surface of the liver seemed to be associated with an increased incidence of major morbidity, multivariate analysis showed no significant correlation between the use of Seprafilm and postoperative major abdominal morbidity.

CONCLUSION

Use of Seprafilm may not increase the risk of major abdominal morbidity in liver surgery.

Stratification of Major Hepatectomies According to Their Outcome: Analysis of 2212 Consecutive Open Resections in Patients Without Cirrhosis

OBJECTIVE

To stratify major hepatectomies (MajHs) according to their outcomes.

SUMMARY OF BACKGROUND DATA

MajHs are associated with non-negligible operative risks, but they include a wide range of procedures. Detailed depiction of the outcomes of different MajHs is the basis for a new classification of liver resections.

METHODS

We retrospectively considered patients that underwent hepatectomy in 17 high-volume centers. Patients with an associated digestive/biliary resection were excluded. We analyzed open MajHs in non-cirrhotic patients. MajHs were classified according to the Brisbane nomenclature. Right hepatectomies (RHs) were reference standards. Outcomes were adjusted for potential confounders, including indication, liver function, preoperative portal vein embolization, and enrolling center.

RESULTS

We analyzed a series of 2212 patients. In comparison with RH, left hepatectomy had lower mortality [0.6% vs 2.2%, odds ratio (OR) = 0.25], severe morbidity (11.7% vs 14.4%, OR = 0.62), and liver failure rates (2.1% vs 11.6%, OR = 0.16). Left hepatectomy+Sg1 and mesohepatectomy+/-Sg1 had outcomes similar to RH, except for higher bile leak rate (31.3% and 13.5% vs 6.7%, OR = 4.36 and OR = 2.29). RH + Sg1 had slightly worse outcomes than RH. Right and left trisectionectomies had higher mortality (5.0% and 7.3% vs 2.2%, OR = 2.07 and OR = 2.71) and liver failure rates than RH (19.0% and 22.0% vs 11.6%, OR = 2.03 and OR = 2.21). Left trisectionectomy had even higher severe morbidity (25.6% vs 14.4%, OR = 2.07) and bile leak rates (14.6% vs 6.7%, OR = 2.31).

CONCLUSIONS

The term "major hepatectomy" includes resections having heterogeneous outcome. Different MajHs can be stratified according to their mortality, severe morbidity, liver failure, and bile leak rates.

Issues to be considered to address the future liver remnant prior to major hepatectomy

An accurate preoperative evaluation of the hepatic function and application of portal vein embolization in selected patients have helped improve the safety of major hepatectomy. In planning major hepatectomy, however, several issues remain to be addressed. The first is which cut-off values for serum total bilirubin level and prothrombin time should be used to define post-hepatectomy liver failure. Other issues include what minimum future liver remnant (FLR) volume is required; whether the total liver volume measured using computed tomography or the standard liver volume calculated based on the body surface area should be used to assess the adequacy of the FLR volume; whether there is a discrepancy between the FLR volume and function during the recovery period after portal vein embolization or hepatectomy; and how best the function of a specific FLR can be assessed. Various studies concerning these issues have been reported with controversial results. We should also be aware that different strategies and management are required for different types of liver damage, such as cirrhosis in hepatocellular carcinoma, cholangitis in biliary tract cancer, and chemotherapy-induced hepatic injury.

Comprehensive Complication Index Validates Improved Outcomes Over Time Despite Increased Complexity in 3707 Consecutive Hepatectomies

OBJECTIVE

The aim of this study was to evaluate trends over time in perioperative outcomes for patients undergoing hepatectomy.

BACKGROUND

As perioperative care and surgical technique for hepatectomy have improved, the indications for and complexity of liver resections have evolved. However, the resulting effect on the short-term outcomes over time has not been well described.

METHODS

Consecutive patients undergoing hepatectomy during 1998 to 2015 at 1 institution were analyzed. Perioperative outcomes, including the comprehensive complication index (CCI), were compared between patients who underwent hepatectomy in the eras 1998 to 2003, 2004 to 2009, and 2010 to 2015.

RESULTS

The study included 3707 hepatic resections. The number of hepatectomies increased in each era (794 in 1998 to 2003, 1402 in 2004 to 2009, and 1511 in 2010 to 2015). Technical complexity increased over time as evidenced by increases in the rates of major hepatectomy (20%, 23%, 30%, P < 0.0001), 2-stage hepatectomy (0%, 3%, 4%, P < 0.001), need for portal vein embolization (5%, 9%, 9%, P = 0.001), preoperative chemotherapy for colorectal liver metastases (70%, 82%, 89%, P < 0.001) and median operative time (180, 175, 225 minutes, P < 0.001). Significant decreases over time were observed in median blood loss (300, 250, 200 mL, P < 0.001), transfusion rate (19%, 15%, 5%, P < 0.001), median length of hospitalization (7, 7, 6 days, P < 0.001), rates of CCI ≥26.2 (20%, 22%, 16%, P < 0.001) and 90-day mortality (3.1%, 2.6%, 1.3%, P < 0.01). On multivariable analysis, hepatectomy in the most recent era 2010 to 2015 was associated with a lower incidence of CCI ≥26.2 (odds ratio 0.7, 95% confidence interval 0.6-0.8, P < 0.0001).

CONCLUSION

Despite increases in complexity over an 18-year period, continued improvements in surgical technique and perioperative outcomes yielded a resultant decrease in CCI in the most current era.

Dynamic Changes in Normal Liver Parenchymal Volume During Chemotherapy for Colorectal Cancer: Liver Atrophy as an Alternate Marker of Chemotherapy-Associated Liver Injury

BACKGROUND

The purpose of this study was to investigate the incidence, origin, and clinical significance of liver atrophy during chemotherapy for colorectal cancer.

METHODS

This study included 103 patients who underwent chemotherapy before resection for colorectal liver metastases (training set) and 171 patients who underwent adjuvant or first-line chemotherapy without liver resection (validation set). A greater than 10% decrease (atrophy) or increase (hypertrophy) of the liver volume from the baseline was defined as a significant change.

RESULTS

In the training set, the numbers of patients who developed atrophy, no change of volume, and hypertrophy of the liver after chemotherapy were 15 (14.6%), 73 (70.9%), and 15 (14.6%), respectively. Liver atrophy was associated with impaired hepatic function, and the postoperative morbidity rate and refractory ascites/pleural effusion were higher in the patients with liver atrophy than those without (60.0% vs. 31.8%, P = 0.045 and 46.7% vs. 8.0%, P < 0.001, respectively). Histopathological examination revealed a strong association between sinusoidal injury and liver atrophy (P < 0.001). The cumulative incidence of liver atrophy increased with increasing duration of chemotherapy, whereas the incidence of liver atrophy was less frequent in patients who had received bevacizumab than those who had not in both the training set (odds ratio [OR], 0.13; P = 0.001) and the validation set (OR, 0.31; P = 0.007).

CONCLUSIONS

Liver atrophy is associated with impaired hepatic functional reserve and observed at an increasing frequency as the duration of chemotherapy increases with frequent histopathological evidence of sinusoidal injury in the liver. Bevacizumab may protect against the development of liver atrophy.

The transjugular approach is a safe and effective alternative for performing portal vein embolization

To evaluate the safety and efficacy of the novel technique, transjugular portal vein embolization (TPVE).A single-center retrospective review of 18 patients (12 males and 6 females; mean age, 62 years) who underwent TPVE between January 2012 and January 2013 was conducted. The technical success rate, future liver remnant (FLR) volume, total liver volume (TLV) and FLR/TLV ratio after PVE were analyzed. Liver function, including total bilirubin (TB), aspartate aminotransferase (AST), alanine aminotransferase (ALT) and International Normalized Ratio (INR), was assessed before and after PVE. Any complications of TPVE and liver resection after TPVE were recorded.TPVE was performed on 18 patients before right hepatic resection for both primary and secondary hepatic malignancies (10 hepatocellular carcinomas, 4 cases of colorectal liver metastasis, and 4 cholangiocarcinomas). Technical success was achieved in 100% of patients (18 of 18). The mean FRL significantly increased to 580 ± 155 mL (P < .001) after PVE. The mean FLR/TLV ratio (%) significantly increased to 34 ± 4 (P < .001) after PVE. One patient suffered septicemia after TPVE. A small number patients experienced mild to moderate abdominal pain during TPVE. No other major complications occurred after TPVE in our study. The patient who developed septicemia died 3 days after the surgery as a result of this complication and subsequent multiple organ dysfunction syndrome (MODS).Transjugular portal vein embolization is a safe, efficacious, and promising novel technique to induce hypertrophy of the FLR.

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.

Phase contrast imaging of preclinical portal vein embolization with CO2 microbubbles

Preoperative portal vein embolization (PVE) is employed clinically to avoid postoperative liver insufficiency. Animal models are usually used to study PVE in terms of mechanisms and pathophysiological changes. PVE is formerly monitored by conventional absorption contrast imaging (ACI) with iodine contrast agent. However, the side effects induced by iodine can give rise to animal damage and death. In this study, the feasibility of using phase contrast imaging (PCI) to show PVE using homemade CO₂ microbubbles in living rats has been investigated. CO₂ gas was first formed from the reaction between citric acid and sodium bicarbonate. The CO₂ gas was then encapsulated by egg white to fabricate CO₂ microbubbles. ACI and PCI of CO₂ microbubbles were performed and compared in vitro. An additional increase in contrast was detected in PCI. PCI showed that CO₂ microbubbles gradually dissolved over time, and the remaining CO₂ microbubbles became larger. By PCI, the CO₂ microbubbles were found to have certain stability, suggesting their potential use as embolic agents. CO₂ microbubbles were injected into the main portal trunk to perform PVE in living rats. PCI exploited the differences in the refractive index and facilitated clear visualization of the PVE after the injection of CO₂ microbubbles. Findings from this study suggest that homemade CO₂ microbubbles-based PCI is a novel modality for preclinical PVE research.