Portal and arterial embolization before extensive liver resection in patients with markedly poor functional reserve

Portal Vein Embolization: Rationale, Techniques, and Outcomes to Maximize Remnant Liver Hypertrophy with a Focus on Contemporary Strategies

Hepatectomy remains the gold standard for curative therapy for patients with limited primary or metastatic hepatic tumors as it offers the best survival rates. In recent years, the indication for partial hepatectomy has evolved away from what will be removed from the patient to the volume and function of the future liver remnant (FLR), i.e., what will remain. With this regard, liver regeneration strategies have become paramount in transforming patients who previously had poor prognoses into ones who, after major hepatic resection with negative margins, have had their risk of post-hepatectomy liver failure minimized. Preoperative portal vein embolization (PVE) via the purposeful occlusion of select portal vein branches to promote contralateral hepatic lobar hypertrophy has become the accepted standard for liver regeneration. Advances in embolic materials, selection of treatment approaches, and PVE with hepatic venous deprivation or concurrent transcatheter arterial embolization/radioembolization are all active areas of research. To date, the optimal combination of embolic material to maximize FLR growth is not yet known. Knowledge of hepatic segmentation and portal venous anatomy is essential before performing PVE. In addition, the indications for PVE, the methods for assessing hepatic lobar hypertrophy, and the possible complications of PVE need to be fully understood before undertaking the procedure. The goal of this article is to discuss the rationale, indications, techniques, and outcomes of PVE before major hepatectomy.

Portal vein embolization failure: Current strategies and future perspectives to improve liver hypertrophy before major oncological liver resection

Portal vein embolization (PVE) is currently considered the standard of care to improve the volume of an inadequate future remnant liver (FRL) and decrease the risk of post-hepatectomy liver failure (PHLF). PHLF remains a significant limitation in performing major liver surgery and is the main cause of mortality after resection. The degree of hypertrophy obtained after PVE is variable and depends on multiple factors. Up to 20% of patients fail to undergo the planned surgery because of either an inadequate FRL growth or tumor progression after the PVE procedure (usually 6-8 wk are needed before surgery). The management of PVE failure is still debated, with a lack of consensus regarding the best clinical strategy. Different additional techniques have been proposed, such as sequential transarterial chemoembolization followed by PVE, segment 4 PVE, intra-portal administration of stem cells, dietary supplementation, and hepatic vein embolization. The aim of this review is to summarize the up-to-date strategies to overcome such difficult situations and discuss future perspectives on improving FRL hypertrophy.

Future remnant Liver optimization: preoperative assessment, volume augmentation procedures and management of PVE failure

Surgery is the cornerstone treatment for patients with primary or metastatic hepatic tumors. Thanks to surgical and anesthetic technological advances, current indications for liver resections have been significantly expanded to include any patient in whom all disease can be resected with a negative margin (R0) while preserving an adequate future residual liver (FRL). Post-hepatectomy liver failure (PHLF) is still a feared complication following major liver surgery, associated with high morbidity, mortality and cost implications. PHLF is mainly linked to both the size and quality of the FRL. Significant advances have been made in detailed preoperative assessment, to predict and mitigate this complication, even if an ideal methodology has yet to be defined. Several procedures have been described to induce hypertrophy of the FRL when needed. Each technique has its advantages and limitations, and among them portal vein embolization (PVE) is still considered the standard of care. About 20% of patients after PVE fail to undergo the scheduled hepatectomy, and newer secondary procedures, such as segment 4 embolization, ALPPS and HVE, have been proposed as salvage strategies. The aim of this review is to discuss the current modalities available and new perspectives in the optimization of FRL in patients undergoing major liver resection.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Portal vein embolization: rationale, techniques, outcomes and novel strategies

The incidence of liver cancer has grown in the past decade, with 905,677 new cases and 830,180 deaths in 2020. According to the highest annual fatality ratio, liver cancer is the third-leading cause of cancer-related deaths worldwide. Surgical resection is the mainstay treatment for long-term survival. However, only 25% of patients are surgical candidates. Recent surgical concepts, techniques and multidisciplinary management were developed, including interventional radiology procedures that improve the management algorithm, expand the indications and limit dropouts from curative treatment. This review summarizes up-to-date information on interventional radiology in the management of liver tumors.

The Future Liver Remnant : Definition, Evaluation, and Management

When considering patients for a major hepatectomy, one must carefully consider the volume of liver to be left behind and if additional procedures are necessary to augment its volume. This review considers the optimal volume of the future liver remnant (FLR) and analyzes the techniques of augmenting this volume, the various growth parameters to assess adequate growth of the FLR, as well as further management when there has been inadequate growth of the FLR.

Improving the Safety of Major Resection for Hepatobiliary Malignancy: Portal Vein Embolization and Recent Innovations in Liver Regeneration Strategies

PURPOSE OF REVIEW

For three decades, portal vein embolization (PVE) has been the "gold-standard" strategy to hypertrophy the anticipated future liver remnant (FLR) in advance of major hepatectomy. During this time, CT volumetry was the most common method to preoperatively assess FLR quality and function and used to determine which patients are appropriate surgical candidates. This review provides the most up-to-date methods for preoperatively assessing the anticipated FLR and summarizes data from the currently available strategies used to induce FLR hypertrophy before surgery for hepatobiliary malignancy.

RECENT FINDINGS

Functional and physiological imaging is increasingly replacing standard CT volumetry as the method of choice for preoperative FLR assessment. PVE, associating liver partition and portal vein ligation, radiation lobectomy, and liver venous deprivation are all currently available techniques to hypertrophy the FLR. Each strategy has pros and cons based on tumor type, extent of resection, presence or absence of underlying liver disease, age, performance status, complication rates, and other factors. Numerous strategies can lead to FLR hypertrophy and improve the safety of major hepatectomy. Which is best has yet to be determined.

Preparing for liver surgery with "Alphabet Soup": PVE, ALPPS, TAE-PVE, LVD and RL

Future liver remnant (FLR) size and function is a critical limiting factor for treatment eligibility and postoperative prognosis when considering surgical hepatectomy. Pre-operative portal vein embolization (PVE) has been proven effective in modulating FLR and now widely accepted as a standard of care. However, PVE is not always effective due to potentially inadequate augmentation of the FLR as well as tumor progression while awaiting liver growth. These concerns have prompted exploration of alternative techniques: associating liver partition and portal vein ligation for staged hepatectomy (ALPPS), transarterial embolization-portal vein embolization (TAE-PVE), liver venous deprivation (LVD), and radiation lobectomy (RL). The article aims to review the principles and applications of PVE and these newer hepatic regenerative techniques.

Ethanol ablation for refractory bile leakage after complex hepatectomy

BACKGROUND

Only a few reports exist on the use of ethanol ablation for posthepatectomy bile leakage. The aim of this study was to assess the value of ethanol ablation in refractory bile leakage.

METHODS

Medical records of consecutive patients who underwent a first hepatobiliary resection with bilioenteric anastomosis between 2007 and 2016 were reviewed retrospectively, with special attention to bile leakage and ethanol ablation therapy. Bile leakage was graded as A/B1/B2 according to the International Study Group of Liver Surgery definition. Absolute ethanol was injected into the target bile duct during fistulography.

RESULTS

Of the 609 study patients, 237 (38·9 per cent) had bile leakage, including grade A in 33, grade B1 in 18 and grade B2 in 186. Left trisectionectomy was more often associated with grade B2 bile leakage than other types of hepatectomy (P < 0·001). Of 186 patients with grade B2 bile leakage, 31 underwent ethanol ablation therapy. Ethanol ablation was started a median of 34 (range 15-122) days after hepatectomy. The median number of treatments was 3 (1-7), and the total amount of ethanol used was 15 (3-71) ml. Complications related to ethanol ablation included transient fever (27 patients) and mild pain (13). Following ethanol ablation, bile leakage resolved in all patients and drains were removed. The median interval between the first ablation and drain removal was 28 (1-154) days.

CONCLUSION

Ethanol ablation is safe and effective, and may be a treatment option for refractory bile leakage.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

ALPPS as a salvage procedure after insufficient future liver remnant hypertrophy following portal vein occlusion

BACKGROUND

A minimum future liver remnant (FLR) of 30% is required to avoid post hepatectomy liver failure (PHLF). Portal vein occlusion (PVO) is the main strategy to induce hypertrophy of the FLR, but some patients will not reach sufficient FLR hypertrophy to enable resection. Recently ALPPS has emerged as a "Salvage Procedure" for PVO failure. The aim of this study was to report the short term outcomes of ALPPS following PVO failure.

METHODS

A retrospective analysis of patients enrolled within the international ALPPS Registry between October 2012 and November 2015 (NCT01924741) was performed. Patients with documented PVO failure were included. The outcomes reported included feasibility, FLR growth rate and safety of ALPPS. Complications were recorded as per Clavien-Dindo classification.

RESULTS

From 510 patients enrolled in the Registry there were 22 patients with previous PVO failure. Two patients were excluded due to missing data and twenty patients were analysed. All of them completed the proposed ALPPS with a medium FLR increase of 88% (23-115%) between two stages and no 90-day mortality.

CONCLUSION

In experienced centers, ALPPS following PVO failure is feasible and safe. The FLR hypertrophy was similar to other ALPPS series. ALPPS is a potential rescue strategy after PVO failure.

ALPPS Procedure in Insufficient Hypertrophy After Portal Vein Embolization (PVE)

BACKGROUND

The main limiting factor for major liver resections is the volume and function of the future remnant liver (FLR). Portal vein embolization (PVE) is now standard in most centers for preoperative hypertrophy of FLR. However, it has a failure rate of about 20-30 %. In these cases, the "Associating Liver Partition and Portal Vein Ligation for Staged Hepatectomy" (ALPPS) may represent a suitable and possibly the only alternative.

METHODS

We performed a retrospective analysis of nine patients who had ALPPS following an insufficient hypertrophy after PVE. Computed tomography volumetry were performed before and after PVE as well as the first step of ALPPS. Furthermore, complications, 30-day mortality and outcome were analyzed.

RESULTS

The FLR volume rose significantly by 77.7 ± 40.7 % (FLR/TLV: 34.9 ± 9.7 %) as early as 9 days after the first stage despite insufficient hypertrophy after preoperative portal vein embolization. Major complications (Grade > IIIb) occurred in 33 % of the patients, and 30-day mortality was 11.1 %. The OS at 1 and 2 years was 78 and 44 %. Four patients are presently still alive at a median of 33.4 (range 15-48) months (survival rate 44.4 %).

CONCLUSION

The ALPPS procedure could be a suitable alternative for patients following insufficient PVE or indeed the last chance of a potentially curative treatment in this situation. Nevertheless, the high morbidity and mortality rates and the lack of data on the long-term oncological outcome must also be taken into account.

Portal Vein Embolization: State-of-the-Art Technique and Options to Improve Liver Hypertrophy

Portal vein embolization (PVE) is associated with a high technical and clinical success rate for induction of future liver remnant hypertrophy prior to surgical resection. The degree of hypertrophy is variable and depends on multiple factors, including technical aspects of the procedure and underlying chronic liver disease. For patients with insufficient liver volume following PVE, adjunctive techniques, such as intra-portal administration of stem cells, dietary supplementation, transarterial embolization, and hepatic vein embolization, are available. Our purpose is to review the state-of-the-art technique associated with high-quality PVE and to discuss options to improve hypertrophy of the future liver remnant.

Postoperative Biliary Leak Treated with Chemical Bile Duct Ablation Using Absolute Ethanol: A Report of Two Cases

Case series

Patient: Female, 72 • Male, 78

Final Diagnosis: Postoperative biliary leakage

Symptoms: Refractory and intractable symptoms

Medication: —

Clinical Procedure: Chemical ablation

Specialty: Surgery

Portal Venous Interventions: State of the Art

In recent decades, there have been numerous advances in the management of liver cancer, cirrhosis, and diabetes mellitus. Although these diseases are wide ranging in their clinical manifestations, each can potentially be treated by exploiting the blood flow dynamics within the portal venous system, and in some cases, adding cellular therapies. To aid in the management of these disease states, minimally invasive transcatheter portal venous interventions have been developed to improve the safety of major hepatic resection, to reduce the untoward effects of sequelae from end-stage liver disease, and to minimize the requirement of exogenously administered insulin for patients with diabetes mellitus. This state of the art review therefore provides an overview of the most recent data and strategies for utilization of preoperative portal vein embolization, transjugular intrahepatic portosystemic shunt placement, balloon retrograde transvenous obliteration, and islet cell transplantation.

Portal vein embolization for induction of selective hepatic hypertrophy prior to major hepatectomy: rationale, techniques, outcomes and future directions

The ability to modulate the future liver remnant (FLR) is a key component of modern oncologic hepatobiliary surgery practice and has extended surgical candidacy for patients who may have been previously thought unable to survive liver resection. Multiple techniques have been developed to augment the FLR including portal vein embolization (PVE), associating liver partition and portal vein ligation (ALPPS), and the recently reported transhepatic liver venous deprivation (LVD). PVE is a well-established means to improve the safety of liver resection by redirecting blood flow to the FLR in an effort to selectively hypertrophy and ultimately improve functional reserve of the FLR. This article discusses the current practice of PVE with focus on summarizing the large number of published reports from which outcomes based practices have been developed. Both technical aspects of PVE including volumetry, approaches, and embolization agents; and clinical aspects of PVE including data supporting indications, and its role in conjunction with chemotherapy and transarterial embolization will be highlighted. PVE remains an important aspect of oncologic care; in large part due to the substantial foundation of information available demonstrating its clear clinical benefit for hepatic resection candidates with small anticipated FLRs.

Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS): impact of the inter-stages course on morbi-mortality and implications for management

BACKGROUND

Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) was recently developed to induce rapid hypertrophy and reduce post-hepatectomy liver failure in patients with insufficient remnant liver volume (RLV). However, mortality rates >12% have been reported. This study aimed to analyze the perioperative course of ALPPS and to identify factors associated with morbi-mortality.

METHODS

Between April 2011 and September 2013, 62 patients operated in 9 Franco-Belgian hepatobiliary centres underwent ALPPS for colorectal metastases (N = 50) or primary tumors, following chemotherapy (N = 50) and/or portal vein embolization (PVE; N = 9).

RESULTS

Most patients had right (N = 31) or right extended hepatectomy (N = 25) (median RLV/body weight ratio of 0.54% [0.21-0.77%]). RLV increased by 48.6% [-15.3 to 192%] 7.8 ± 4.5 days after stage1, but the hypertrophy decelerated beyond 7 days. Stage2 was cancelled in 3 patients (4.8%) for insufficient hypertrophy, portal vein thrombosis or death and delayed to ≥9 days in 32 (54.2%). Overall, 25 patients (40.3%) had major complication(s) and 8 (12.9%) died. Fourteen patients (22.6%) had post-stage1 complication of whom 5 (35.7%) died after stage2. Factors associated with major morbi-mortality were obesity, post-stage1 biliary fistula or ascites, and infected and/or bilious peritoneal fluid at stage2. The latter was the only predictor of Clavien ≥3 by multivariate analysis (OR: 4.9; 95% CI: 1.227-19.97; p = 0.025). PVE did not impact the morbi-mortality rates but prevented major cytolysis that was associated with poor outcome.

CONCLUSIONS

The inter-stages course was crucial in determining ALPPS outcome. The factors of high morbi-mortality rates associated with ALPPS are linked to the technique complexity.

Effect of hepatic artery embolization on liver hypertrophy response in a rabbit liver VX2 tumor model

BACKGROUND

Portal vein embolization not only induces hypertrophy of the non-embolized liver, but also enhances tumor growth. The latter could be prevented by embolizing the hepatic arteries supplying the tumor-bearing liver segments. This study aimed to determine the effects of transcatheter arterial embolization (TAE) on tumor volume and liver regeneration in a rabbit VX2 tumor model.

METHODS

Twenty-three rabbits underwent subcapsular tumor implantation with a VX2 tumor. Two weeks after implantation, 18 rabbits were used for TAE experiments, 5 were for sham controls. Tumor response and liver regeneration response of the embolized cranial and non-embolized caudal liver lobes were assessed by CT volumetry, liver to body weight index, and the amount of proliferating hepatocytes.

RESULTS

All super-selective arterial tumor embolization procedures were performed successfully. Despite embolization, the tumor volume increased after an initial steady state. The tumor volume after embolization was smaller than that of the sham group, but this difference was not significant. Massive necrosis of the tumor, however, was seen after embolization, without damage of the surrounding liver parenchyma. There was a significant atrophy response of the tumor bearing cranial lobe after super-selective arterial embolization of the tumor with a concomitant hypertrophy response of the non-embolized, caudal lobe. This regeneration response was confirmed histologically by a significantly higher number of proliferating hepatocytes on the Ki-67 stained slides.

CONCLUSIONS

Super-selective, bland arterial coil embolization causes massive necrosis of the tumor, despite increase of volume on CT scan. Atrophy of the tumor bearing liver lobe is seen after arterial embolization of the tumor with a concomitant hypertrophy response of the non-embolized lobe, despite absence of histological damage of the tumor-surrounding liver parenchyma.

Salvage parenchymal liver transection for patients with insufficient volume increase after portal vein occlusion -- an extension of the ALPPS approach

BACKGROUND

Portal vein ligation (PVL) or embolization (PVE) are standard approaches to induce liver hypertrophy of the future liver remnant (FLR) prior to hepatectomy in primarily non-resectable liver tumors. However, this approach fails in about one third of patients. Recently, the new "ALPPS" approach has been described that combines PVL with parenchymal transection to induce rapid liver hypertrophy. This series explores whether isolated parenchymal transection boosts liver hypertrophy in scenarios of failed PVL/PVE.

METHODS

A multicenter database with 170 patients undergoing portal vein manipulation to increase the size of the FLR was screened for patients undergoing isolated parenchymal transection as a salvage procedure. Three patients who underwent PVL/PVE with subsequent insufficient volume gain and subsequently underwent parenchymal liver transection as a salvage procedure were identified. Patient characteristics, volume increase, postoperative complications and outcomes were analyzed.

RESULTS

The first patient underwent liver transection 16 weeks after failed PVL with a standardized FLR (sFLR) of 30%, which increased to 47% in 7 days. The second patient showed a sFLR of 25% 28 weeks after PVL and subsequent PVE of segment IV, which increased to 41% in 7 days after transection. The third patient underwent liver partition 8 weeks after PVE with a sFLR of 19%, which increased to 37% in six days. All patients underwent a R0 resection.

CONCLUSION

Failed PVE or PVL appears to represent a good indication for the isolated parenchymal liver transection according to the newly developed ALPPS approach.

The role of interventional radiology in the treatment of hepatocellular carcinoma

The incidence of hepatocellular carcinoma (HCC) in the UK is increasing. The role of interventional radiology in the treatment of HCC is well established. We discuss the minimally invasive treatment options that are available. It is important that procedures are undertaken in and postprocedure imaging is reviewed by centers with accredited hepatobiliary units. This is when the best outcomes are achieved. Advances in tumor biology and in technology will continue to expand the role of interventional radiology in the treatment of HCC in the future.

Update on portal vein embolization: evidence-based outcomes, controversies, and novel strategies

Portal vein embolization (PVE) is an established therapy used to redirect portal blood flow away from the tumor-bearing liver to the anticipated future liver remnant (FLR) and usually results in FLR hypertrophy. PVE is indicated when the FLR is considered too small before surgery to support essential function after surgery. When appropriately applied, PVE reduces postoperative morbidity and increases the number of patients eligible for curative hepatic resection. PVE also has been combined with other therapies to improve patient outcomes. This article assesses more recent outcomes data regarding PVE, reviews the existing controversies, and reports on novel strategies currently being investigated.

Perihilar cholangiocarcinoma: a surgeon's viewpoint on current topics

Perihilar cholangiocarcinomas are defined anatomically as "tumors that are located in the extrahepatic biliary tree proximal to the origin of the cystic duct". However, as the boundary between the extrahepatic and intrahepatic bile ducts is not well defined, perihilar cholangiocarcinomas potentially include two types of tumors: one is the "extrahepatic" type, which arises from the large hilar bile duct, and the other is the "intrahepatic" type, which has an intrahepatic component with the invasion of the hepatic hilus. The new TNM staging system published by the International Union Against Cancer (UICC) has been well revised with regard to perihilar cholangiocarcinoma, but it still lacks stratification of patient prognosis and has little applicability for assessing the feasibility of surgical treatment; therefore, further refinement is essential. Most patients with perihilar cholangiocarcinomas present with jaundice, and preoperative biliary drainage is mandatory. Previously, percutaneous transhepatic biliary drainage was used in many centers; however, it is accepted that endoscopic naso-biliary drainage is the most suitable method of preoperative drainage. Portal vein embolization is now widely used as a presurgical treatment for patients undergoing an extended hepatectomy to minimize postoperative liver dysfunction. The surgical resection of a perihilar cholangiocarcinoma is technically demanding and continues to be the most difficult challenge for hepatobiliary surgeons. Because of advances in diagnostic and surgical techniques, surgical outcomes and survival rates after resection have steadily improved. However, survival, especially for patients with lymph node metastasis, is still unsatisfactory, and the establishment of adjuvant chemotherapy is necessary. Further synergy of endoscopists, radiologists, oncologists, and surgeons is required to conquer this intractable disease.

Impact of preoperative targeted therapy on postoperative complications after resection of colorectal liver metastases

PURPOSE

The impact of chemotherapy (CTx) on morbidity after liver resection for colorectal metastases (CRC-LM) has been increasingly investigated during recent years. Biologic agents like bevacizumab (BEV) or cetuximab (CET) are now added as "targeted therapy" (TT), also in neoadjuvant settings. Initial series could demonstrate the safety of those regimens in liver resection but data are still scarce. We evaluated the impact of CTx with BEV or CET (CTx + TT) on perioperative morbidity and mortality.

METHODS

Two hundred thirty-seven patients who underwent liver resections for CRC-LM after chemotherapy before surgery since 1999 were included. One hundred eighty-five patients (78%) had preoperative CTx regimen without biologic agents (fluoropyrimidine-, oxaliplatin-, or irinotecan-based) and 52 (22%) had CTx + TT (39 BEV, 11 CET, 2 CET/BEV). After preoperative CTx + TT, a time interval of at least 4-6 weeks and a residual liver volume of >35% before surgery were required.

RESULTS

Hemihepatectomy or more was performed in about half of the patients. The median amount of intraoperatively transfused blood was 0 ml in both groups (p = 0.34). Overall mortality was 1.7% and slightly elevated in patients with CTx + TT (3.8% vs. 1.1%, p = 0.17). Any complication occurred in (CTx + TT vs. CTx) 52% and 46%, respectively (p = 0.47). The rates of liver failure (9.6% vs. 9.7%, p = 0.98), infectious complications such as wound infection (19% vs. 16%, p = 0.62) and abdominal abscess (8% vs. 6.5%, p = 0.71), as well as the rate of relaparotomies (11.5% vs. 7.0%, p = 0.29) showed no significant differences between the groups with TT or without. In multivariate analyses, neither type nor duration of CTx nor the time interval between CTx and surgery showed any influence on complication rates.

CONCLUSIONS

Our data confirm the safety of targeted therapy before liver resection for CRC-LM. This effect may in part be due to our treatment policy (time interval to resection and residual liver volume) after intensive preoperative CTx.

Strategies for resection using portal vein embolization: hepatocellular carcinoma and hilar cholangiocarcinoma

Preoperative portal vein embolization (PVE) is increasingly used to optimize the volume and function of the future liver remnant (FLR) and to reduce the risk for complications of major hepatectomy for hepatocellular carcinoma (HCC) or hilar cholangiocarcinoma (CCA). In patients with HCC who are candidates for extended hepatectomy and in patients with HCC and well-compensated cirrhosis who are being considered for major hepatectomy, FLR volumetry is routinely performed, and PVE is employed in selected cases to optimize the volume and function of the FLR prior to surgery. Similarly, in patients with hilar CCA who are candidates for extended hepatectomy, careful preoperative preparation using biliary drainage, FLR volumetry, and PVE optimizes the volume and function of the FLR prior to surgery. Appropriate use of PVE has led to improved postoperative outcomes after major hepatectomy for these diseases and oncological outcomes similar to those in patients who undergo resection without PVE. Specific indications for PVE are being clarified. FLR volumetry is necessary for proper selection of patients for PVE. Analysis of the degree of hypertrophy of the FLR after PVE (a dynamic test of liver regeneration) complements analysis of the pre-PVE FLR volume (a static test). Together, FLR degree of hypertrophy and FLR volume are the best predictors of outcome after major hepatectomy in an individual patient, regardless of the degree of underlying liver disease. This article synthesizes the literature on the approach to patients with HCC and CCA who are candidates for major hepatectomy. The rationale and indications for FLR volumetry and PVE and outcomes following PVE and major hepatectomy for HCC and CCA are discussed.

Value of indocyanine green clearance of the future liver remnant in predicting outcome after resection for biliary cancer

BACKGROUND

It is difficult to predict hepatic functional reserve accurately before major hepatectomy. The aim of this study was to analyse the usefulness of the future liver remnant plasma clearance rate of indocyanine green (ICGK-F, calculated as plasma clearance rate of indocyanine green (ICGK) x proportion of the future liver remnant) in predicting death after major hepatectomy.

METHODS

Data on ICGK and ICGK-F were collected prospectively and analysed retrospectively for 274 patients who underwent right hepatectomy, right trisectionectomy or left trisectionectomy for biliary cancer between 1991 and 2008. The mortality rate and incidence of postoperative complications were analysed. Patients were separated into two groups according to year of operation (85 patients operated on between 1991 and 2000; 189 from 2001 to 2008).

RESULTS

In multiple logistic regression analyses, an ICGK-F less than 0.05 had the strongest impact on the incidence of postoperative mortality (odds ratio 8.06; P < 0.001). The postoperative mortality rate was significantly lower in the later period (P < 0.001). In patients with an ICGK-F value between 0.040 and 0.049, the mortality rate in the early period was 30 per cent, whereas it was only 8 per cent in the later period.

CONCLUSION

An ICGK-F of 0.05 is a useful cut-off value for predicting mortality and morbidity. With careful perioperative patient management in an experienced institution, this cut-off value can be lowered further.

Transcatheter arterial chemoembolization for hepatocellular carcinoma after attempted portal vein embolization in 25 patients

OBJECTIVE

Portal vein embolization (PVE) has been widely used to facilitate major liver resection; however, curative surgery even after PVE may not be possible mainly because of inadequate hypertrophy of remnant liver or disease progression. For these patients, transcatheter arterial chemoembolization (TACE) is the next therapeutic option. We evaluated the safety and efficacy of TACE after PVE in 25 patients with hepatocellular carcinoma (HCC).

CONCLUSION

TACE using a single chemotherapeutic agent can be performed safely and effectively in HCC patients who previously underwent PVE. TACE after PVE allowed two of the patients to be downstaged so they could undergo surgical resection.

Interventional oncology: new options for interstitial treatments and intravascular approaches: right hepatic vein embolization after right portal vein embolization for inducing hypertrophy of the future liver remnant

Extensive hepatic resection is often associated with post-hepatectomy liver failure. Owing to the regenerative capacity of the liver, preoperative portal vein embolization (PVE) has been proposed to increase the functional mass of the non-embolized liver segments that will remain in situ after surgery. However, in some patients, hypertrophy of the non-embolized liver segments following PVE is insufficient to support major hepatectomy. Several studies have demonstrated alternative techniques for inducing hypertrophy of the non-embolized liver segments, including PVE in conjunction with hepatic arterial embolization or hepatic vein embolization in conjunction with PVE. Investigation of new techniques for inducing hypertrophy of the future liver remnant can reasonably be expected to expand the selection criteria for extensive hepatic resection.

Surgical treatment of hilar cholangiocarcinoma in the new era: the Asan experience

BACKGROUND/PURPOSE

Both curative resection and minimized in-hospital mortality offer the only chance of long-term survival in patients with hilar cholangiocarcinoma. The reported resectability rates for hilar cholangiocarcinoma have increased by virtue of combined major hepatectomy, but this procedure is technically demanding and still associated with a significant morbidity and mortality that must be carefully balanced against the chances of long-term survival.

METHODS

Between January 2001 and December 2008, 350 patients with hilar cholangiocarcinoma underwent exploration for the purpose of potentially curative resection, of whom 302 (86.3%) were resected in the Department of Hepato-Biliary Surgery and Liver Transplantation, Asan Medical Center, University of Ulsan College of Medicine. Combined hepatectomy was carried out in 268 (88.7%) of 302 resected patients. Major hemihepatectomy and parenchyma-preserving hepatectomy were performed in 257 and 11 patients, respectively. Portal vein resection was associated in 40 (14.9%) of 268 hepatectomized patients. To control preoperative cholangitis and reduce risk of postoperative hepatic failure, biliary decompression through endoscopic and/or percutaneous transhepatic drainage and portal vein embolization were preoperatively applied in 329 (94.0%) of 350 explored patients and in 91 (54.2%) of 168 extended hepatectomized patients (154 right hemihepatectomy, 9 right trisectionectomy, 5 left trisectionectomy), respectively. Liver transplantation was not performed as primary treatment for hilar cholangiocarcinoma.

RESULTS

There were 5 cases (1.7%) of in-hospital death after resection and 1 postoperative liver failure that was successfully treated with liver transplantation. Major complications were encountered in 23 patients (7.0%), and the overall morbidity rate was 43%. In 302 resections, 214 (70.9%) were curative resections (R0) and 88 (29.1%) were palliative resections (R1). The overall 1-, 3- and 5-year survival rates after resection, including in-hospital deaths, were 84.6, 50.7 and 47.3% in the R0 group and 69.9, 33.3 and 7.5% in the R1 group, respectively. The 5-year survival rate of extended hemihepatectomy of 36.4% was better than that of parenchyma-preserving hepatectomy at 10.5%. Two significant predictive factors adversely affecting survival after resection were lymph node metastasis and incurability of surgery (P < 0.001). Two patients with vascular involvement who underwent concomitant hepatic artery and portal vein reconstruction are alive after more than 3 years.

CONCLUSION

Preoperative biliary decompression and portal vein embolization enabled us to reduce in-hospital deaths associated with extended hepatectomy for hilar cholangiocarcinoma. Major hemihepatectomy offers an increased survival because of the higher possibility of curative resection than bile duct resection alone and parenchyma-preserving hepatectomy, but it still carries a certain mortality. Less extensive procedures can be conducted safely and are beneficial for aged patients in poor condition with a less advanced tumor stage if tumor-free resectional margins are obtained.

Sequential preoperative ipsilateral hepatic vein embolization after portal vein embolization to induce further liver regeneration in patients with hepatobiliary malignancy

OBJECTIVE

To assess the effect of ipsilateral hepatic vein embolization (HVE) performed after portal vein embolization (PVE) on liver regeneration.

SUMMARY BACKGROUND DATA

PVE induces shrinkage of the embolized lobe and compensatory enlargement of the non-embolized lobe, but it does not always induce sufficient liver regeneration. There was no effective method to accelerate liver regeneration in addition to PVE yet.

METHODS

During a 1-year study period, preoperative HVE were performed on 12 patients who had shown limited liver regeneration after PVE awaiting right hepatectomy. The right hepatic vein was embolized with multiple coils after insertion of vena cava filters or vascular plugs.

RESULTS

No HVE procedure-related complications occurred, but embolization of the wrong hepatic vein trunk occurred in 1 patient. The increase in blood liver enzymes after HVE was comparable with that after PVE alone. In 9 patients who underwent hepatectomy, the proportions of future liver remnant volume to total liver volume were 34.8% +/- 1.5% before PVE, 39.7% +/- 0.6% 1 to 2 weeks after PVE, 44.2% +/- 1.1% 2 weeks after HVE, and 64.5% +/- 6.2% 1 week after right hepatectomy. Cirrhotic livers showed lower regeneration rates following HVE after PVE and 1 patient underwent hepatectomy 17 months after HVE. Immunohistochemistry showed that apoptosis occurred more in the liver area affected by both PVE and HVE than in that affected by PVE alone.

CONCLUSIONS

Preoperative sequential application of PVE and HVE seems to be safe and effective in facilitating contralateral liver regeneration by inducing more severe liver damage than PVE alone.

Portal vein embolization using a nitinol plug (Amplatzer vascular plug) in combination with histoacryl glue and iodinized oil: adequate hypertrophy with a reduced risk of nontarget embolization

The purpose of this study was to assess whether portal vein embolization (PVE) using a nitinol vascular plug in combination with histoacryl glue and iodinized oil minimizes the risk of nontarget embolization while obtaining good levels of future liver remnant (FLR) hypertrophy. Between November 2005 and August 2008, 16 patients (8 females, 8 males; mean age, 63 +/- 3.6 years), each with a small FLR, underwent right ipsilateral transhepatic PVE prior to major hepatectomy. Proximal PVE was initially performed by placement of a nitinol vascular plug, followed by distal embolization using a mixture of histoacryl glue and iodinized oil. Pre- and 6 weeks postprocedural FLR volumes were calculated using computed tomographic imaging. Selection for surgery required an FLR of 0.5% of the patient's body mass. Clinical course and outcome of surgical resection for all patients were recorded. At surgery, the ease of hepatectomy was subjectively assessed in comparison to previous experience following PVE with alternative embolic agents. PVE was successful in all patients. Mean procedure time was 30.4 +/- 2.5 min. Mean absolute increase in FLR volume was 68.9% +/- 12.0% (p = 0.00005). There was no evidence of nontarget embolization during the procedure or on subsequent imaging. Nine patients proceeded to extended hepatectomy. Six patients demonstrated disease progression. One patient did not achieve sufficient hypertrophy in relation to body mass to undergo hepatic resection. At surgery, the hepatobiliary surgeons observed less periportal inflammation compared to previous experience with alternative embolic agents, facilitating dissection at extended hepatectomy. In conclusion, ipsilateral transhepatic PVE using a single nitinol plug in combination with histoacryl glue and iodinized oil simplifies the procedure, offering short procedural times with minimal risk of nontarget embolization. Excellent levels of FLR hypertrophy are achieved enabling safe extended hepatectomy.

Liver failure after major hepatic resection

INTRODUCTION

The consequence of excessive liver resection is the inexorable development of progressive liver failure characterised by the typical stigmata associated with this condition, including worsening coagulopathy, hyperbilirubinaemia and encephalopathy. The focus of this review will be to investigate factors contributing to hepatocyte loss and impaired regeneration.

METHODS

A literature search was undertaken of Pubmed and related search engines, examining for articles relating to hepatic failure following major hepatectomy.

RESULTS

In spite of improvements in adjuvant chemotherapy and increasing surgical confidence and expertise, the parameters determining how much liver can be resected have remained largely unchanged. A number of preoperative, intraoperative and post-operative factors all contribute to the likelihood of liver failure after surgery.

CONCLUSIONS

Given the magnitude of the surgery, mortality and morbidity rates are extremely good. Careful patient selection and preservation of an obligate volume of remnant liver is essential. Modifiable causes of hepatic failure include avoidance of sepsis, drainage of cholestasis with restoration of enteric bile salts and judicious use of portal triad inflow occlusion intra-operatively. Avoidance of post-operative sepsis is most likely to be achieved by patient selection, meticulous intra-operative technique and post-operative care. Modulation of portal vein pressures post-operatively may further help reduce the risk of liver failure.

Recent advances in the treatment of hilar cholangiocarcinoma: portal vein embolization

The clinical application of portal vein embolization (PVE) has contributed to improving the postoperative outcome of hilar cholangiocarcinoma. The enlarged nonembolized lobe after PVE protects the patient from postoperative hepatic failure, due to the increased functional reserve, and shortens the hospital stay. Although numerous reports have shown beneficial effects of PVE on postoperative outcome after extended hepatectomy, no randomized controlled study has been performed so far. It is urgent to establish a "gold standard" of PVE, because the indications, approach to the portal vein, types of embolic materials, and methods used to evaluate the function of the future liver remnant are variable among institutions. The indications and procedures of PVE for hilar cholangiocarcinoma may be different from those for hepatocellular carcinoma or colorectal metastasis, because, in many patients with hilar cholangiocarcinoma, biliary cancer is associated with biliary obstruction and cholangitis. This review article summarizes the contribution of PVE to the outcome of postoperative management in patients with hilar cholangiocarcinoma needing extended hepatectomy. We also describe our PVE procedure, which has been established from our experience of more than 240 cases of biliary cancer. Furthermore, the drawbacks of PVE, which may reduce the pool of candidates for surgery, are also discussed.

Mechanisms of hepatic regeneration following portal vein embolization and partial hepatectomy: a review

BACKGROUND

Portal vein embolization (PVE) improves outcome following major hepatectomy, and basic studies have presented evidence related to the mechanisms responsible for hepatic regeneration. Hemodynamic changes following PVE are similar to, but slightly different from, those of partial hepatectomy (PH) because arterial flow to the embolized lobe is preserved. However, the process of hepatic regeneration is essentially the same after both PVE and PH. A number of mediators are involved in PVE or PH-induced hepatic regeneration. These include inflammatory cytokines, vasoregulators, growth factors, eicosanoids, and various hormones. These mediators activate a complex network of signal transduction that promotes hepatic regeneration. A variety of conditions have been shown to modulate the function of these mediators and inhibit regeneration. These include biliary obstruction, diabetes, chronic ethanol consumption, malnutrition, gender, aging, and infection.

CONCLUSION

Optimizing these factors, where possible, before PVE or PH, is essential to maximize hypertrophy of the liver. A fuller understanding of hepatic physiology and pathophysiology following PVE or PH may lead to greater functional capacity of the remaining liver and extend the indications for hepatectomy in patients who require large liver volume resection.

Transarterial versus Transhepatic Portal Vein Embolization to Induce Selective Hepatic Hypertrophy: A Comparative Study in Swine

PURPOSE

Portal vein embolization (PVE) is used to induce liver hypertrophy for surgical candidates with marginal future liver remnant (FLR) volumes. We compared the feasibility, safety, and effectiveness of a transarterial approach for PVE (TA-PVE) with those of a transhepatic approach for PVE (TH-PVE) in a swine model.

MATERIALS AND METHODS

Ten experimental pigs (TA-PVE, n = 5; TH-PVE, n = 5) and six controls (TA, n = 3; TH, n = 3) were studied. For TA-PVE, a microcatheter was advanced into arteries supplying the left and left middle hepatic lobes. A 3 to 1 Ethiodol-ethanol mixture was infused into selected arteries to cross the arterioportal peribiliary plexus and remain within the portal veins (PVs). For TH-PVE, PVs in the same lobar distribution were embolized with 355- to 500-micro m polyvinyl alcohol particles and coils. Controls were similarly catheterized for saline infusion. Computed tomography with volumetry was performed before and 7, 14, 21, and 28 days after PVE to assess FLR hypertrophy (absolute FLR volume change and FLR/total liver volume [TLV]). Computed tomographic volumetry, laboratory data, and histopathology were compared between groups.

RESULTS

All procedures were technically successful. The increases in mean absolute FLR volume (TA-PVE, 148 +/- 84 cm(3); TH-PVE, 62 +/- 19 cm(3); P = .082), mean FLR hypertrophy (TA-PVE, 93.2%; TH-PVE, 48.4%; P = .178), and mean FLR/TLV (TA-PVE, 31.0%; TH-PVE, 16.2%; P = .130) from day 0 to day 28 between experimental groups were better for TA-PVE. Changes in laboratory data among all groups were minimal. Two complications occurred from TA-PVE (right gastric artery embolization [n = 2] without sequela) and two from TH-PVE (acute segmental right PV thrombosis [n = 1]; death 3 weeks after PVE of unknown cause [n = 1]).

CONCLUSIONS

Transarterial portal vein embolization is feasible, safe, and effective for inducing future liver remnant hypertrophy in swine and may represent an improvement over previously reported transhepatic portal vein embolization methods.

Two hundred forty consecutive portal vein embolizations before extended hepatectomy for biliary cancer: surgical outcome and long-term follow-up

OBJECTIVE

To assess clinical benefit of portal vein embolization (PVE) before extended, complex hepatectomy for biliary cancer.

SUMMARY BACKGROUND DATA

Many investigators have addressed clinical utility of PVE before simple hepatectomy for metastatic liver cancer or hepatocellular carcinoma, but few have reported PVE before hepatectomy for biliary cancer due to the limited number of surgical cases.

METHODS

This study involved 240 consecutive patients with biliary cancer (150 cholangiocarcinomas and 90 gallbladder cancers) who underwent PVE before an extended hepatectomy (right or left trisectionectomy or right hepatectomy). All PVEs were performed by the "ipsilateral approach" 2 to 3 weeks before surgery. Hepatic volume and function changes after PVE were analyzed, and the outcome also was reviewed.

RESULTS

There were no procedure-related complications requiring blood transfusion or interventions. Of the 240 patients, 47 (19.6%) did not undergo subsequent hepatectomy. The incidence of unresectability was higher in gallbladder cancer than in cholangiocarcinoma (32.2% versus 12.0%, P < 0.005). The remaining 193 patients (132 cholangiocarcinomas and 61 gallbladder cancers) underwent hepatectomy with resection of the caudate lobe and extrahepatic bile duct (n = 187), pancreatoduodenectomy (n = 42), and/or portal vein resection (n = 63). Seventeen (8.8%) patients died of postoperative complications: mortality was higher in gallbladder cancer than in cholangiocarcinoma (18.0% versus 4.5%, P < 0.05); and it was also higher in patients whose indocyanine green clearance (KICG) of the future liver remnant after PVE was <0.05 than those whose index was >or=0.05 (28.6% versus 5.5%, P < 0.001). The 3- and 5-year survival after hepatectomy was 41.7% and 26.8% in cholangiocarcinoma and 25.3% and 17.1% in gallbladder cancer, respectively (P = 0.011). In 136 other patients with cholangiocarcinoma who underwent a less than 50% resection of the liver without PVE, a mortality of 3.7% and a 5-year survival of 27.6% were observed, which was similar to the 132 patients with cholangiocarcinoma who underwent extended hepatectomy after PVE.

CONCLUSIONS

PVE has the potential benefit for patients with advanced biliary cancer who are to undergo extended, complex hepatectomy. Along with the use of PVE, further improvements in surgical techniques and refinements in perioperative management are necessary to make difficult hepatobiliary resections safer.

Portal Vein Embolization with N-Butyl Cyanoacrylate before Partial Hepatectomy in Patients with Hepatocellular Carcinoma and Underlying Cirrhosis or Advanced Fibrosis

PURPOSE

To describe the safety, complications, and liver regeneration associated with the left liver after embolization of the right portal vein (PV) in patients with hepatocellular carcinoma (HCC) developed in the setting of advanced liver fibrosis and cirrhosis.

MATERIALS AND METHODS

Forty patients (31 men, nine women; mean age, 62 years) with HCC underwent PV embolization over a 4-year period. Embolization was performed from a left PV percutaneous access with use of n-butyl cyanoacrylate (NBCA) mixed with iodized oil. Computed tomography (CT) volumetry was performed before and 1 month after PV embolization to measure the left lobe volume as well as the functional liver ratio defined by the ratio between the left lobe and the total liver volume minus tumoral volume. PV pressure and liver enzyme levels were compared before and 1 month after the procedure and complications were registered. Factors potentially affecting regeneration (age, sex, diabetes, chemoembolization, functional liver ratio before PV embolization, and Knodell histologic score) were evaluated by one-way and stepwise regression analysis.

RESULTS

PV embolization could be achieved successfully in all cases. Two patients had partial PV thrombosis on the 1-month follow-up CT and two patients developed transient ascites after PV embolization. The left lobe volume increase was 41% +/- 32% after PV embolization and the functional liver ratio increased from 28% +/- 10% to 36% +/- 10% (P < .0001). Hypertrophy of the left lobe was greater in patients with a low functional liver ratio before PV embolization and those with an F3 fibrosis score. Other factors had no influence on left lobe regeneration.

CONCLUSION

PV embolization with use of NBCA is feasible in patients with advanced fibrosis and cirrhosis. Hypertrophy of the left lobe of the liver after PV embolization has a statistically significant correlation with lower functional liver ratio and lower degrees of fibrosis.

Portal vein embolization with use of polyvinyl alcohol particles

Preoperative portal vein embolization has been used as method of inducing compensatory hypertrophy in the future remnant liver since it was first described in the late 1980s. Many different vascular embolic agents have been successfully used for this procedure, and there is no general consensus regarding which is the best agent. Polyvinyl alcohol (PVA) particles commonly used for arterial embolization come in many sizes, are readily available, and are easy to administer via conventional catheters. We describe an easy, safe, and effective method of the use of PVA particles for portal vein embolization.