Portal vein embolization: utility for inducing left hepatic lobe hypertrophy before surgery

Negative impact of chemotherapy on kinetic growth rate of the future liver remnant if applied following PVE or ALPPS

PURPOSE

Modern liver surgery has improved the percentage of potentially resectable malignant tumors. However, if the future liver remnant is small, patients remain at risk of developing postoperative liver failure. Thus, the future liver remnant must be increased, while at the same time, the primary tumor may have to be controlled by chemotherapy. To address this conflict, we retrospectively analyzed the changes in hypertrophy before and after Associating Liver Partition with Portal vein ligation for Staged hepatectomy (ALPPS) or Portal Vein Embolization (PVE), with or without parallel systemic chemotherapy.

MATERIALS AND METHODS

We retrospectively analysed 172 patients (54 female and 118 male), treated with ALPPS in 90 patients (median age 61 years [Q1, Q3: 52,71]) and with PVE in 82 patients (median age 66 years [Q1, Q3: 56,73]). The median control interval was 4.9 [Q1, Q3: 4.0, 6.0] weeks after the PVE, and 2.6 [Q1, Q3: 1.6, 5.8] weeks after ALPPS step 1.

RESULTS

The overall kinetic growth rate (median) for the entire group was 0.02 (2%) per week. When systemic chemotherapy was administered prior to intervention, the kinetic growth rate of these treated patients (vs. untreated) exhibited a median of 0.020 [Q1, Q3: 0.011, 0.067] compared to 0.024 [Q1, Q3: 0.013, 0.041] (p = 0.949). When chemotherapy was administered after the PVE/ ALPPS treatment, the kinetic growth rate declined from a median of 0.025 [Q1, Q3: 0.013, 0.053] to 0.011 [Q1, Q3: 0.007, 0.021] (p = 0.005). Subgroup analysis showed statistically significant effects only in the PVE group (median ALPPS -45% (p = 0.157), PVE -47% (p = 0.005)).

CONCLUSION

This retrospective analysis indicated that systemic chemotherapy given after PVE/ the first step of the ALPPS procedure, i.e., the growth phase, has a negative effect on the kinetic growth rate.

Preoperative Portal Vein Embolization: Basics Interventional Radiologists Need to Know

One of the major reasons for unresectability of the liver is that the remnant liver volume is insufficient to support postoperative liver function. Post-hepatectomy liver insufficiency is one of the most serious complications in patients undergoing major hepatic resection. Preoperative portal vein embolization is performed with the aim of inducing hypertrophy of the future liver remnant and is thought to reduce the risk of liver insufficiency after hepatectomy. We, interventional radiologists, are required to safely complete the procedure to promote future liver remnant hypertrophy as possible and understand portal vein anatomy variations and hemodynamics, embolization techniques, and how to deal with possible complications. The basic information interventional radiologists need to know about preoperative portal vein embolization is discussed in this review.

CIRSE Standards of Practice on Portal Vein Embolization and Double Vein Embolization/Liver Venous Deprivation

This CIRSE Standards of Practice document is aimed at interventional radiologists and provides best practices for performing liver regeneration therapies prior to major hepatectomies, including portal vein embolization, double vein embolization and liver venous deprivation. It has been developed by an expert writing group under the guidance of the CIRSE Standards of Practice Committee. It encompasses all clinical and technical details required to perform liver regeneration therapies, revising the indications, contra-indications, outcome measures assessed, technique and expected outcomes.

A comprehensive study and extensive review of the Caudate lobe: The last piece of "Jigsaw" puzzle

Many liver surgeons have updated their understanding of the liver in recent years because of detailed studies on the liver anatomy and the rapid advances in laparoscopic liver surgery. Despite newer approaches, concepts and methods, research on the caudate lobe continues to be based on case reports and several persistent challenges concerning caudate lobe surgery that are worth discussing. Based on the literature and the author's experience, this study considers and addresses the challenges associated with caudate lobectomy encountered by most liver surgeons. We searched PubMed for relevant articles in English for 'caudate lobe', 'cholangiocellular carcinoma', 'laparoscopic caudate resection', 'right-side boundary of the caudate lobe' and 'assessment of hepatic functional reserve' published up to May 2022. This study reviewed the anatomical history of the caudate lobe, focusing on the challenges associated with caudate lobe-related surgical resection. Due to the unique anatomical position of the caudate lobe, surgical strategy for caudate lobe resection is particularly important, and the technical requirements for hepatobiliary surgeons are also extremely strict. Therefore, understanding the anatomical history of the caudate lobe and discussing the challenges associated with caudate lobectomy is essential.

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). Posthepatectomy 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 was to discuss the current modalities available and new perspectives in the optimization of FRL in patients undergoing major liver resection.

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.

Ipsilateral access portal venous embolization (PVE) for preoperative hypertrophy exhibits low complication rates in Clavien-Dindo and CIRSE scales

Background

Portal venous embolization (PVE) is a minimal invasive preoperative strategy that aims to increase future liver remnant (FLR) in order to facilitate extended hemihepatectomy. We analyzed our data retrospectively regarding complications and degree of hypertrophy (DH).

Methods: 88 patients received PVE either by particles / coils (n = 77) or by glue / oil (n = 11), supported by 7 right hepatic vein embolizations (HVE) by coils or occluders. All complications were categorized by the Clavien- Dindo (CD) and the CIRSE classification.

Results

In 88 patients (median age 68 years) there was one intervention with a biliary leak and subsequent drainage (complication grade 3 CD, CIRSE 3), two with prolonged hospital stay (grade 2 CD, grade 3 CIRSE) and 13 complications grade 1 CD, but no complications of grade 4 or higher neither in Clavien- Dindo nor in CIRSE classification. The median relative increase in FLR was 47% (SD 35%). The mean pre-intervention standardized FLR rose from 23% (SD 10%) to a post-intervention standardized FLR of 32% (SD 12%). The degree of hypertrophy (DH) was 9,3% (SD 5,2%) and the kinetic growth rate (KGR) per week was 2,06 (SD 1,84).

Conclusion

PVE and, if necessary, additional sequential HVE were safe procedures with a low rate of complications and facilitated sufficient preoperative hypertrophy of the future liver remnant.

BestFLR Trial: Liver Regeneration at CT before Major Hepatectomies for Liver Cancer-A Randomized Controlled Trial Comparing Portal Vein Embolization with N-Butyl-Cyanoacrylate Plus Iodized Oil versus Polyvinyl Alcohol Particles Plus Coils

Background In patients with liver cancer, portal vein embolization (PVE) is recommended to promote liver growth before major hepatectomies. However, the optimal embolization strategy has not been established. Purpose To compare liver regeneration as seen at CT in participants with liver cancer, before major hepatectomies, with N-butyl-cyanoacrylate (NBCA) plus iodized oil versus standard polyvinyl alcohol (PVA) particles plus coils, for PVE. Materials and Methods In this single-center, prospective, randomized controlled trial (Best Future Liver Remnant, or BestFLR, trial; International Standard Randomized Controlled Trial Number 16062796), PVE with NBCA plus iodized oil was compared with standard PVE with PVA particles plus coils in participants with liver cancer. Participant recruitment started in November 2017 and ended in March 2020. Participants were randomly assigned to undergo PVE with PVA particles plus coils or PVE with NBCA plus iodized oil. The primary end point was liver growth assessed with CT 14 days and 28 days after PVE. Secondary outcomes included posthepatectomy liver failure, surgical complications, and length of intensive care treatment and hospital stay. The Mann-Whitney U test was used to compare continuous outcomes according to PVE material, whereas the Χ² test or Fisher exact test was used for categoric variables. Results Sixty participants (mean age, 61 years ± 11 [standard deviation]; 32 men) were assigned to the PVA particles plus coils group (n = 30) or to the NBCA plus iodized oil group (n = 30). Interim analysis revealed faster and superior liver hypertrophy for the NBCA plus iodized oil group versus the PVA particles plus coils group 14 days and 28 days after PVE (absolute hypertrophy of 46% vs 30% [P < .001] and 57% vs 37% [P < .001], respectively). Liver growth for the proposed hepatectomy was achieved in 87% of participants (26 of 30) in the NBCA plus iodized oil group versus 53% of participants (16 of 30) in the PVA particles plus coils group (P = .008) 14 days after PVE. Liver failure occurred in 13% of participants (three of 24) in the NBCA plus iodized oil group and in 27% of participants (six of 22) in the PVA particles plus coils group (P = .27). Conclusion Portal vein embolization with N-butyl-cyanoacrylate plus iodized oil produced greater and faster liver growth as seen at CT in participants with liver cancer, compared with portal vein embolization with polyvinyl alcohol particles plus coils, allowing for earlier surgical intervention. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Arellano in this issue.

Deportalization, Venous Congestion, Venous Deprivation: Serial Measurements of Volumes and Functions on Morphofunctional 99mTc-Mebrofenin SPECT-CT

The objective was to assess the changes in regional volumes and functions under venous-impaired vascular conditions following liver preparation. Twelve patients underwent right portal vein embolization (PVE) (n = 5) or extended liver venous deprivation (eLVD, i.e., portal and right and middle hepatic veins embolization) (n = 7). Volume and function measurements of deportalized liver, venous-deprived liver and congestive liver were performed before and after PVE/eLVD at days 7, 14 and 21 using 99mTc-mebrofenin hepatobiliary scintigraphy with single-photon emission computed tomography and computed tomography (99mTc-mebrofenin SPECT-CT). Volume and function progressed independently in the deportalized liver (p = 0.47) with an early decrease in function (median −18.2% (IQR, −19.4–−14.5) at day 7) followed by a decrease in volume (−19.3% (−22.6–−14.4) at day 21). Volume and function progressed independently in the venous deprived liver (p = 0.80) with a marked and early decrease in function (−41.1% (−52.0–−12.9) at day 7) but minimal changes in volume (−4.7% (−10.4–+3.9) at day 21). Volume and function progressed independently in the congestive liver (p = 0.21) with a gradual increase in volume (+43.2% (+38.3–+51.2) at day 21) that preceded a late and moderate increase in function at day 21 (+34.8% (−8.3–+46.6)), concomitantly to the disappearance of hypoattenuated congestive areas in segment IV (S4) on CT, initially observed in 6/7 patients after eLVD and represented 35.3% (22.2–46.4) of whole S4 volume. Liver volume and function progress independently whatever the vascular condition. Hepatic congestion from outflow obstruction drives volume increase but results in early impaired function.

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.

[Interventional radiology of liver tumors]

Interventional radiology (IR) has considerably grown since the 90s and has currently a central position in the management of patients suffering from cancer. The aim of this paper is to describe the principle, indications, technique and results of three common hepatic oncologic IR procedures: preoperative portal vein embolization, transarterial chemoembolization and radioembolization. Portal vein embolization is performed before a right hepatectomy in order to increase the left liver volume and functional capacity to ensure adequate liver function of the future remnant liver and to prevent the post-hepatectomy liver failure. It is a proven, well-tolerated and effective technique, allowing most of patients to undergo surgery. Transarterial chemoembolization consists of an injection of a chemotherapeutic agent and an embolic agent into the hepatic artery to locally act on liver tumors. It is the standard of care for BCLC stage B hepatocellular carcinoma and is also recommended for the liver metastases treatment, mainly from neuroendocrine tumors. Radioembolization is an IR procedure on the rise that consists of the injection into the hepatic artery of Yttrium 90 loaded microparticles, which will preferentially deliver high dose on the tumors, sparing the adjacent hepatic parenchyma. Radioembolization is recommended for the palliative treatment of HCC and for colorectal cancer liver metastases resistant to treatment. It is a very well tolerated intervention which place has yet to be defined in the management of neuroendocrine tumors liver metastases and unresectable cholangiocarcinoma. IR is a constantly evolving discipline with proven techniques playing a major role in the oncological management of liver tumor patients. In oncology, IR is now the 4th patient management linchpin alongside oncology, surgery and radiotherapy.

CD133 + cell infusion in patients with colorectal liver metastases going to be submitted to a major liver resection (CELLCOL): A randomized open label clinical trial

BACKGROUND

Treatment of liver metastases of colorectal carcinoma is surgical resection. However, only 10-15% of the patients in this context will be candidate for curative resection arising other 10-13% after response to neoadyuvant chemotherapy. In order to perform the liver metastases surgery, it is necessary to have a sufficient remnant liver volume (RLV) which allows maintaining an optimal liver function after resection. Studies on liver regeneration have determined that CD133 + stem cells are involved in liver hypertrophy developed after an hepatectomy with encouraging results. As presented in previous studies, CD133 + stem cells can be selected from peripheral blood after stimulation with G-CSF, being able to obtain a large number of them. We propose to treat patients who do not meet criteria for liver metastases surgery because of insufficient RLV (<40%) with CD133 + cells together with portal embolization, in order to achieve enough liver volume which avoids liver failure.

METHODS

/Design: The aim of this study is to evaluate the effectiveness of preoperative PVE plus the administration of CD133 + mobilized from peripheral blood with G-CSF compared to PVE only. SECONDARY AIMS ARE: to compare the grade of hypertrophy, speed and changes in liver function, anatomopathological study of hypertrophied liver, to determine the safety of the treatment and analysis of postoperative morbidity and surveillance.

STUDY DESIGN

Prospective randomized longitudinal phase IIb clinical trial, open, to evaluate the efficacy of portal embolization (PVE) together with the administration of CD133 + cells obtained from peripheral blood versus PVE alone, in patients with hepatic metastasis of colorectal carcinoma (CCRHM).

DISCUSSION

The number of CD133 + obtained from peripheral blood after G -CSF stimulation will be far greater than the number obtained with direct puncture of bone marrow. This will allow a greater intrahepatic infusion, which could have a direct impact on achieving a larger and quicker hypertrophy. Consequently, it will permit the treatment of a larger number of patients with an increase on their survival.

TRIAL REGISTRATION

ClinicalTrials.gov, ID NCT03803241.

The technical aspects of a feasible new technique for ipsilateral percutaneous transhepatic portal vein embolization

OBJECTIVE:

To devise a simple new technique wherein absolute ethanol is injected via a sheath under proximal balloon occlusion of the right portal vein using a single-balloon catheter and to examine its feasibility and safety for ipsilateral portal vein embolization (PVE).

METHODS:

Between 2010 and 2016, PVE was performed in 19 patients prior to undergoing extended right hepatectomy. PVE was performed via a percutaneous transhepatic ipsilateral approach, the right portal branch was embolized under ultrasound guidance, and a balloon catheter was placed in the proximal site of the main right portal branch. Absolute ethanol was injected through a sheath under proximal balloon occlusion of the right portal vein using a double-lumen catheter. We evaluated its technical success and complications following PVE and changes in liver enzyme levels. Furthermore, we calculated changes in future liver remnant (FLR) and FLR/total functional liver volume (TFLV) ratio and assessed complications following hepatic resection.

RESULTS:

PVE was successfully performed in all patients. Mean FLR and FLR/TFLV significantly increased following PVE (p < 0.01). The change in the FLR and FLR/TFLV ratio was 39.6 ± 16.2%. One patient (6.5%) developed procedure-related complications following PVE (perihepatic hematoma).

CONCLUSION:

The new technique for ipsilateral right PVE is safe, effective, and convenient.

ADVANCES IN KNOWLEDGE:

This is the first study to investigate the efficacy of injecting ethanol via a sheath under proximal balloon occlusion of the right portal vein using a single-balloon catheter.

Point-shear wave elastography predicts liver hypertrophy after portal vein embolization and postoperative liver failure

PURPOSE

To correlate point-shear wave elastography (SWE) with liver hypertrophy after right portal vein embolization (RPVE) and to determine its usefulness in predicting postoperative liver failure in patients undergoing partial liver resection.

PATIENTS AND METHODS

Point-SWE was performed the day before RPVE in 56 patients (41 men) with a median age of 66 years. The percentage (%) of future remnant liver (FRL) volume increase was defined as: %FRL_post-%FRL_pre%FRL_pre×100 and assessed on computed tomography performed 4 weeks after RPVE.

RESULTS

Median (range) %FRL_pre and %FRL_post was respectively, 31.5% (12-48%) and 41% (23-61%) (P<0.001), with a median %FRL volume increase of 25.6% (-8; 123%). SWE correlated with %FRL volume increase (P=-0.510; P<0.001). SWV (P=0.003) and %FRL_pre (P<0.001) were associated with %FRL volume increase at multivariate regression analysis. Forty-three patients (77%) were operated. Postoperative liver failure occurred in 14 patients (32.5%). Median SWE was different between the group with (1.68m/s) and without liver failure (1.07m/s) (P=0.018). The AUROC of SWE predicting liver failure was 0.724 with a best cut-off of 1.31m/s, corresponding to a sensitivity of 21%, specificity of 96%, positive predictive value 75% and negative predictive value of 72%. SWE was the single independent preoperative variable associated with liver failure.

CONCLUSIONS

SWE assessed by point-SWE is a simple and useful tool to predict the FRL volume increase and postoperative liver failure in a population of patients with liver tumor.

Portal Vein Embolization Utilizing N-Butyl Cyanoacrylate for Contralateral Lobe Hypertrophy Prior to Liver Resection: A Systematic Review and Meta-Analysis

PURPOSE

To evaluate the safety and effectiveness of n-butyl cyanoacrylate (NBCA) for portal vein embolization (PVE) when used to induce contralateral future liver remnant (FLR) hypertrophy in patients undergoing planned hepatic resection for hepatic malignancy.

MATERIALS AND METHODS

The PubMed database (including articles indexed by MEDLINE) was searched for articles published from 1970 to 2018 describing patients treated with PVE utilizing NBCA to induce hypertrophy of the FLR prior to contralateral hepatic lobe resection. Demographic data, embolization technique, complications of embolization, resultant FLR hypertrophy, and surgical outcomes were obtained when available. A meta-analysis was performed to determine the cumulative relative hypertrophy rate of the FLR following PVE with NBCA.

RESULTS

The literature search yielded 18 relevant articles. Six hundred and seven patients (383 men, 220 women; mean age 60.7 years) with procedures describing PVE utilizing NBCA were reviewed. The most common underlying hepatic malignancies were colorectal metastases (n = 348), followed by cholangiocarcinomas (n = 92), and hepatocellular carcinomas (n = 89). Technical success was reportedly achieved in 603/607 patients, for a success rate of 99.3%. Fixed effects meta-analysis of the relative hypertrophy rate of the FLR among studies resulted in an aggregate rate of 49.4 ± 1.3%. Of the patients who underwent attempted PVE, 461/607 (75.9%) eventually underwent surgical resection. Major complications following PVE occurred in 19 patients (3.13%), while minor complications following PVE occurred in 38 patients (6.26%).

CONCLUSIONS

PVE utilizing NBCA to induce hypertrophy of the FLR prior to contralateral lobe resection in the setting of hepatic malignancy is safe and effective.

LEVEL OF EVIDENCE

Level IIa-Systematic review of cohort studies.

Portal vein embolisation in a patient with situs inversus

Portal vein embolisation (PVE) is a well-established technique used for patients who require major hepatic resections without sufficient volume of future remnant liver (FRL). We describe a case of PVE in a patient with situs inversus. Computed Tomography (CT) 4 weeks after the procedure demonstrated significant hypertrophy of the FRL. However, the surgical procedure was aborted due to signs of extrahepatic progression.

Portal vein embolization with n-butyl-cyanoacrylate through an ipsilateral approach before major hepatectomy: single center analysis of 50 consecutive patients

Purpose

To evaluate the efficacy of portal vein embolization (PVE) with n-Butyl-cyanoacrylate (NBCA) through an ipsilateral approach before major hepatectomy. Secondary end-points were PVE safety, liver resection and patient outcome.

Methods

Over a 5-year period 50 non-cirrhotic consecutive patients were included with primary or secondary liver cancer treatable by hepatectomy with a liver remnant (FLR) volume less than 25% or less than 40% in diseased livers.

Results

There were 37 men and 13 women with a mean age of 57 years. Colorectal liver metastases were the most frequent tumor and patients were previously exposed to chemotherapy. FLR increased from 422 ml to 629 ml (P < 0.001) after PVE, corresponding to anincrease of 52%. The FLR ratio increased from 29.6% to 42.3% (P < 0.001). Kinetic growth rate was 2.98%/week. A negative association was observed between increase in the FLR and FLR ratio and FLR volume before PVE (P = 0.002). In 31 patients hepatectomy was accomplished and only one patient presented with liver insufficiency within 30 days after surgery.

Conclusions

PVE with NBCA through an ipsilateral puncture is effective before major hepatectomy. Meticulous attention is needed especially near the end of the embolization procedure to avoid complications.

Trial registration

Clinical Study ISRCTN registration number: ISRCTN39855523. Registered March 13th 2017.

[Portal vein embolization: Present and future]

Portal vein embolization consists of occluding a part of the portal venous system in order to achieve the hypertrophy of the non-embolized liver segments. This technique is used during the preoperative period of major liver resection when the future remnant liver (FRL) volume is insufficient, exposing to postoperative liver failure, main cause of death after major hepatectomy. Portal vein embolization indication depends on the FRL, commonly assessed by its volume. Nowadays, FRL function evaluation seems more relevant and can be measured by 99mTc labelled mebrofenin scintigraphy. Portal vein embolization procedure is mostly performed with percutaneous trans-hepatic access by using ultrasonography guidance and consists of embolic agent injection, such as cyanoacrylate, in the targeted portal vein branches with fluoroscopic guidance. It is a safe and well-tolerated technique, with extremely low morbi-mortality. Portal vein embolization leads to sufficient FRL hypertrophy in about 80% of patients, allowing them to undergo surgery from which they were initially rejected. The two main reasons of non-resection are tumor progression (≈15% of cases) and FRL insufficient hypertrophy (≈5% of cases). When portal vein embolization is not enough to obtain adequate FRL regeneration, hepatic vein embolization may potentiate its effect (liver venous deprivation technique).

Use of an absorbable embolization material for reversible portal vein embolization in an experimental model

BACKGROUND

Portal vein embolization (PVE) is used to increase future remnant liver size in patients requiring major hepatic resection. PVE using permanent embolization, however, predisposes to complications and excludes the use of PVE in living donor liver transplantation. In the present study, an absorbable embolization material containing fibrin glue and different concentrations of the fibrinolysis inhibitor aprotinin was used in an experimental animal model.

METHODS

PVE of the cranial liver lobes was performed in 30 New Zealand White rabbits, which were divided into five groups, fibrin glue + 1000, 700, 500, 300 or 150 kunits/ml aprotinin, and were compared with a previous series of permanent embolization using the same experimental set-up. Caudal liver lobe hypertrophy was determined by CT volumetry, and portal recanalization was identified on contrast-enhanced CT images. Animals were killed after 7 or 42 days, and the results were compared with those of permanent embolization.

RESULTS

PVE using fibrin glue with aprotinin as embolic material was effective, with 500 kunits/ml providing the optimal hypertrophic response. Lower concentrations of aprotinin (150 and 300 kunits/ml) led to reduced hypertrophy owing to early recanalization of the embolized segments. The regeneration rate over the first 3 days was higher in the group with 500 kunits/ml aprotinin than in the groups with 300 or 150 kunits/ml or permanent embolization. In the 500-kunits/ml group, four of five animals showed recanalization 42 days after embolization, with minimal histological changes in the cranial lobes following recanalization.

CONCLUSION

Fibrin glue combined with 500 kunits/ml aprotinin resulted in reversible PVE in 80 per cent of animals, with a hypertrophy response comparable to that achieved with permanent embolization material. Surgical relevance Portal vein embolization (PVE) is used to increase future remnant liver volume in patients scheduled for major liver resection who have insufficient future remnant liver size to perform a safe resection. The current standard is PVE with permanent embolization materials, which renders patients found to have unresectable disease prone to complications owing to the permanently deportalized liver segments. Absorbable embolization might prevent the PVE-associated morbidity and lower the threshold for its application. In this study, PVE using fibrin glue and aprotinin resulted in an adequate hypertrophy response with 80 per cent recanalization after 42 days. Considering the minor histological changes following recanalization of embolized segments and potentially preserved function, reversible PVE might also be applied in living donor liver transplantation.

Sequential transarterial chemoembolization and portal vein embolization before resection is a valid oncological strategy for unilobar hepatocellular carcinoma regardless of the tumor burden

OBJECTIVE

To investigate the long-term oncological outcome of patients with resectable hepatocellular carcinoma (HCC) undergoing sequential transarterial chemoembolization (TACE) and portal vein embolization (PVE).

METHODS

Analysis of all Child A HCC patients who underwent TACE-PVE before major liver resection from 2006 to 2012 was performed according to whether or not they underwent surgical resection as planned.

RESULTS

54 patients (50 men, 93% median 69-years (range 44-87)) were included. Thirty-nine (72%) patients underwent resection, including 19/25, 16/23, and 4/6 of patients with BCLC A, B, and C (p = 0.839). Twenty-two (56%) had tumor recurrence (median delay 10 months) including 9/19, 11/16, and 2/4 of the patients with BCLC A, B, and C (p = 0.430). Survival was significantly better in resected patients as compared to those who were not resected (median overall survival (OS): 44 vs. 18 months; p < 0.001). Recurrence was associated with a poorer prognosis as compared to patients without recurrence (median OS 43 months vs. not reached; p < 0.001). BCLC stage did not influence survival (p = 0.13).

CONCLUSION

In patients with large unilobar HCC, TACE-PVE leads to resection in most patients, with a good oncological outcome regardless of the tumor burden. When this strategy fails, patients can be managed with TACE despite prior PVE.

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 as an Oncosurgical Strategy Prior to Major Hepatic Resection: Anatomic, Surgical, and Technical Considerations

Preoperative portal vein embolization (PVE) is used to extend the indications for major hepatic resection, and it has become the standard of care for selected patients with hepatic malignancies treated at major hepatobiliary centers. To date, various techniques with different embolic materials have been used with similar results in the degree of liver hypertrophy. Regardless of the specific strategy used, both surgeons and interventional radiologists must be familiar with each other's techniques to be able to create the optimal plan for each individual patient. Knowledge of the segmental anatomy of the liver is paramount to fully understand the liver segments that need to be embolized and resected. Understanding the portal vein anatomy and the branching variations, along with the techniques used to transect the portal vein during hepatic resection, is important because these variables can affect the PVE procedure and the eventual surgical resection. Comprehension of the advantages and disadvantages of approaches to the portal venous system and the various embolic materials used for PVE is essential to best tailor the procedures for each patient and to avoid complications. Before PVE, meticulous assessment of the portal vein branching anatomy is performed with cross-sectional imaging, and embolization strategies are developed based on the patient's anatomy. The PVE procedure consists of several technical steps, and knowledge of these technical tips, potential complications, and how to avoid the complications in each step is of great importance for safe and successful PVE and ultimately successful hepatectomy. Because PVE is used as an adjunct to planned hepatic resection, priority must always be placed on safety, without compromising the integrity of the future liver remnant, and close collaboration between interventional radiologists and hepatobiliary surgeons is essential to achieve successful outcomes.

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.

A comparison of portal vein embolization with poly(2-hydroxyethylmethacrylate) and a histoacryl/lipiodol mixture in patients scheduled for extended right hepatectomy

To determine whether PHEMA [poly(2-hydroxyethylmethacrylate)] is suitable for portal vein embolization in patients scheduled to right hepatectomy and whether it is as effective as the currently used agent (a histoacryl/lipiodol mixture). Two groups of nine patients each scheduled for extended right hepatectomy for primary or secondary hepatic tumor, had right portal vein embolization in an effort to induce future liver remnant (FLR) hypertrophy. One group had embolization with PHEMA, the other one with the histoacryl/lipiodol mixture. In all patients, embolization was performed using the right retrograde transhepatic access. Embolization was technically successful in all 18 patients, with no complication related to the embolization agent. Eight patients of either group developed FLR hypertrophy allowing extended right hepatectomy. Likewise, one patient in each group had recanalization of a portal vein branch. Histology showed that both embolization agents reach the periphery of portal vein branches, with PHEMA penetrating somewhat deeper into the periphery. PHEMA has been shown to be an agent suitable for embolization in the portal venous system comparable with existing embolization agent (histoacryl/lipiodol mixture).

Right portal vein embolization with absolute ethanol in major hepatic resection for hepatobiliary malignancy

BACKGROUND

This study aimed to evaluate the safety and efficacy of preoperative right portal vein embolization (PVE) with absolute ethanol in patients with hepatobiliary malignancies.

METHODS

PVE was performed via a percutaneous transhepatic ipsilateral approach, and the right portal branch was embolized with absolute ethanol. Technical success and complications following PVE, and changes in liver enzyme levels were evaluated. Changes in future liver remnant (FLR) and FLR/total functional liver volume ratio were calculated. Complications following hepatic resection were assessed.

RESULTS

A total of 83 patients with hepatobiliary malignancies (53 men, 30 women; mean age 68 years) underwent right PVE. Tumour types were hilar cholangiocarcinoma (37), liver metastases (14), gallbladder cancer (13), intrahepatic cholangiocellular carcinoma (10) and hepatocellular carcinoma (HCC) (9). PVE was performed successfully in all patients. Four patients (5 per cent) developed complications following PVE (liver abscess 2, left portal vein thrombosis 1, pseudoaneurysm 1), but this did not preclude hepatic resection. Liver enzyme levels rose transiently after PVE. The mean FLR and FLR/total functional liver volume increased after PVE (from 366 to 513 cm(3) and from 31 to 43 per cent respectively; both P < 0·001). Changes in the FLR and FLR/total functional liver volume ratio were comparable between patients with HCC and those with other malignancies (42 and 44 per cent, and 12 and 12 per cent, respectively). Sixty-nine of 83 patients underwent hepatic resection at a median of 25 days after PVE, with no postoperative mortality.

CONCLUSION

Preoperative right PVE with absolute ethanol is safe and effective for induction of selective hepatic hypertrophy in patients with hepatobiliary malignancy.

Portal vein embolization before right hepatectomy or extended right hepatectomy using sodium tetradecyl sulfate foam: technique and initial results

PURPOSE

To evaluate the safety and efficacy of portal vein embolization (PVE) with sodium tetradecyl sulfate (STS) foam.

MATERIALS AND METHODS

A single-center retrospective review of 35 patients (27 men and 8 women; mean age, 61 y) who underwent PVE with STS foam was performed. The technical success rate, rate of PVE at producing adequate future liver remnant (FLR) hypertrophy, and rate of disease progression precluding resection after PVE were analyzed. Complications of PVE and liver resection after PVE were recorded.

RESULTS

PVE was performed on 35 patients before right hepatic resection for both primary and secondary hepatic malignancies (22 hepatocellular carcinoma, 10 metastasis, 2 cholangiocarcinoma, 1 invasive gallbladder carcinoma). Technical success was achieved in 97.1% (34 of 35) of patients. Mean FLR of the total estimated liver volume increased from 24.5% (SD, 7.7%) to 36.5% (SD, 14.5%), a mean percentage increase of 48.8% (SD, 34.3%). PVE produced adequate FLR hypertrophy in 31 of 35 patients (88.6%). Proposed right hepatectomy was subsequently performed in 27 patients (77.1%). One patient remains scheduled for surgery, two had peritoneal spread at surgery and resection was aborted, two had disease progression on imaging after PVE, and three had inadequate FLR hypertrophy with no surgery. One major complication was observed related to PVE that involved nontarget embolization to segment III, which was managed conservatively.

CONCLUSIONS

Preoperative PVE with STS foam is a safe and effective method to induce hypertrophy of the FLR.

Liver segmentation: practical tips

The liver segmentation system, described by Couinaud, is based on the identification of the three hepatic veins and the plane passing by the portal vein bifurcation. Nowadays, Couinaud's description is the most widely used classification since it is better suited for surgery and more accurate for the localisation and monitoring of intra-parenchymal lesions. Knowledge of the anatomy of the portal and venous system is therefore essential, as is knowledge of the variants resulting from changes occurring during the embryological development of the vitelline and umbilical veins. In this paper, the authors propose a straightforward systematisation of the liver in six steps using several additional anatomical points of reference. These points of reference are simple and quickly identifiable in any radiological examination with section imaging, in order to avoid any mistakes in daily practice. In fact, accurate description impacts on many diagnostic and therapeutic applications in interventional radiology and surgery. This description will allow better preparation for biopsy, portal vein embolisation, transjugular intrahepatic portosystemic shunt, tumour resection or partial hepatectomy for transplantation. Such advance planning will reduce intra- and postoperative difficulties and complications.

Preoperative portal vein embolization with a combination of trisacryl microspheres, gelfoam and coils

PURPOSE

To evaluate the safety and efficiency of preoperative portal vein embolization (PVE) with a combination of trisacryl microspheres, gelfoam and coils for inducing lobar hypertrophy in hepatobiliary malignancy patients.

MATERIALS AND METHODS

PVE was performed by a percutaneous left approach in 63 patients with hepatic malignancy (hepatocarcinoma=38, colorectal metastasis=14, cholangiocarcinoma=11). The indication of PVE and surgery was evaluated by hepatic tumor board take into consideration to the tumor extension and the hepatic volume on initial and post-embolization CT-scans. The total functional liver volume (TELV) and future liver remnant (FLR) volume were measured before and 24±5days after PVE to assess FLR, TELV and FLR/TELV ratios. Efficiency evaluation was based on FLR increase, the ability to perform the hepatectomy and the hepatic function after surgery. Safety evaluation was determined by clinical and biological follow-up after embolization and surgery.

RESULTS

PVE was successful in all the patients. The mean FLR volume increases by 57±56% after embolization (449±180cm(3) to 663±254cm(3)) (P<0.0001). The FLR/TELV ratio increases by 11% after PVE (25±8% to 36±12%). Three minors' complications were registered without impact on surgery, and four patients developed portal hypertension. Forty-nine patients underwent hepatectomy; none of them developed liver failure. Surgery was not performed in 14 patients due to tumor progression (n=9), inadequate hypertrophy of FLR (n=1) and portal hypertension (n=4).

CONCLUSION

Preoperative PVE with a combination of trisacryl microspheres, gelfoam and coils is a safe and effective method for inducing contralateral hypertrophy before right hepatectomy in patients with advanced hepatobiliary malignancy.

Interventional oncologic approaches to liver metastases

Metastatic liver disease is the most common cause of death in cancer patients. Complete surgical resection is currently considered the only curative treatment, with only about 25% of patients being amenable to surgery. Therefore, a variety of interventional oncologic techniques have been developed for treating secondary liver malignancies. The aim of these therapies is either to allow patients with unresectable tumors to become surgical candidates, provide curative treatment options in nonsurgical candidates, or improve survival in a palliative or even curative approach. Among these interventional therapies are transcatheter therapies such as portal vein embolization, hepatic artery infusion chemotherapy, transarterial chemoembolization, and radioembolization, as well as interstitial techniques, particularly radiofrequency ablation as the most commonly applied technique. The rationale, application and clinical results of each of these techniques are reviewed on the basis of the current literature. Future prospects such as gene therapy and immunotherapy are introduced.

Portal vein embolization using a Histoacryl/Lipiodol mixture before right liver resection

PURPOSE

The purpose of this retrospective study was to evaluate the efficacy and safety of percutaneous transhepatic portal vein embolization (PVE) of the right liver lobe using Histoacryl/Lipiodol mixture to induce contralateral liver hypertrophy before right-sided (or extended right-sided) hepatectomy in patients with primarily unresectable liver tumors.

METHODS

Twenty-one patients (9 females and 12 males) underwent PVE due to an insufficient future liver remnant; 17 showed liver metastases and 4 suffered from biliary cancer. Imaging was performed prior to and 4 weeks after PVE. Surgery was scheduled for 1 week after a CT or MRI control. The primary study end point was technical success, defined as complete angiographical occlusion of the portal vein. The secondary study end point was evaluation of liver hypertrophy by CT and MRI volumetry and transfer to operability.

RESULTS

In all the patients, PVE could be performed with a Histoacryl/Lipiodol mixture (n = 20) or a Histoacryl/Lipiodol mixture with microcoils (n = 1). No procedure-related complications occurred. The volume of the left liver lobe increased significantly (p < 0.0001) by 28% from a mean of 549 ml to 709 ml. Eighteen of twenty-one patients (85.7%) could be transferred to surgery, and the intended resection could be performed as planned in 13/18 (72.3%) patients.

CONCLUSION

Preoperative right-sided PVE using a Histoacryl/Lipiodol mixture is a safe technique and achieves a sufficient hypertrophy of the future liver remnant in the left liver lobe.

Preoperative percutaneous transhepatic portal vein embolization with ethanol injection

OBJECTIVE

The purpose of this article is to evaluate the feasibility and efficacy of preoperative percutaneous transhepatic portal vein embolization with ethanol injection.

MATERIALS AND METHODS

We retrospectively evaluated 143 patients who underwent percutaneous transhepatic portal vein embolization. Hypertrophy of the future liver remnant was assessed by comparing the volumetric data obtained from CT image data before and after percutaneous transhepatic portal vein embolization. The evaluation of effectiveness was based on changes in the absolute volume of the future liver remnant and the ratio of the future liver remnant to the total estimated liver volume.

RESULTS

Ten of 143 patients (7.0%) underwent additional embolization because of recanalization and insufficient hypertrophy of the future liver remnant. The mean increase in the ratio of the future liver remnant was 33.6% (p < 0.0001), and the mean ratio of future liver remnant to total estimated liver volume increased from 34.9% to 45.7% (p < 0.0001). Although most of the patients complained of pain after ethanol injection, they were gradually relieved of pain in a few minutes by conservative treatment. Fever (38-39°C) was reported after 47 of 151 (31.1%) percutaneous transhepatic portal vein embolization sessions and was resolved within a few days. Transient elevation of the liver transaminases was observed after the procedures and resolved within about a week. Major complications occurred in nine of 151 (6%) percutaneous transhepatic portal vein embolization sessions, but no patients developed hepatic insufficiency or severe complications precluding successful resection. One hundred twenty patients underwent hepatic resection, and two patients developed hepatic failure after surgery.

CONCLUSION

Preoperative percutaneous transhepatic portal vein embolization with ethanol is a feasible and effective procedure to obtain hypertrophy of the future liver remnant for preventing hepatic failure after hepatectomy.

Liver regeneration after portal vein embolization using absorbable and permanent embolization materials in a rabbit model

OBJECTIVE

To compare the safety and hypertrophy response after portal vein embolization (PVE) using 2 absorbable and 3 permanent embolization materials.

BACKGROUND

Portal vein embolization is used to increase future remnant liver volume preoperatively. Application of temporary, absorbable embolization materials could be advantageous in some situations, provided sufficient hypertrophy is achieved from the nonembolized lobe.

METHODS

Six groups of rabbits (n = 5) underwent PVE of 80% of the total liver volume using saline (sham), gelatin sponge, fibrin glue, polyvinyl alcohol particles with coils, n-butyl cyanoacrylate, or polidocanol. The rabbits were killed after 7 days. Portography, computed tomographic volumetry, Doppler ultrasonography, laboratory liver function and damage parameters (nonembolized) liver-to-body weight ratio, immunohistochemistry, and cytokine and growth factor tissue levels were assessed to examine the differences in the liver regeneration response.

RESULTS

Polidocanol was discontinued because of toxic reactions in 3 rabbits. Gelatin sponge was the only material that was absorbed after 7 days and resulted in less hypertrophy of the nonembolized lobe than the other 3 materials. There were no significant differences in hypertrophy response between the other 3 embolization groups. Volumetric data obtained from computed tomography were supported by liver-to-body weight ratio and the amount of proliferating hepatocytes. The volume gain of the nonembolized lobe was proportional to the volume loss of the embolized liver lobes. The number of Kupffer cells in the embolized liver lobe was significantly higher in the fibrin glue, polyvinyl alcohol particles with coils, and n-butyl cyanoacrylate groups than in the sham and gelatin sponge groups. However, the levels of interleukin-6, tumor necrosis factor-α, hepatocyte growth factor, and transforming growth factor-β1 were significantly lower.

CONCLUSIONS

Temporary occlusion using gelatin sponge for PVE resulted in significantly less hypertrophy response than the use of permanent embolization materials. Except for polidocanol, none of the embolization materials exhibited evident hepatotoxicity.

31P MR spectroscopic imaging detects regenerative changes in human liver stimulated by portal vein embolization

PURPOSE

First, to evaluate hepatocyte phospholipid metabolism and energetics during liver regeneration stimulated by portal vein embolization (PVE) using proton-decoupled (31)P MR spectroscopic imaging ((31)P-MRSI). Second, to compare the biophysiologic differences between hepatic regeneration stimulated by PVE and by partial hepatectomy (PH).

MATERIALS AND METHODS

Subjects included six patients with hepatic metastases from colorectal cancer who were scheduled to undergo right PVE before definitive resection of right-sided tumor. (31)P-MRSI was performed on the left liver lobe before PVE and 48 h following PVE. Normalized quantities of phosphorus-containing hepatic metabolites were analyzed from both visits. In addition, MRSI data at 48 h following partial hepatectomy were compared with the data from the PVE patients.

RESULTS

At 48 h after PVE, the ratio of phosphomonoesters to phosphodiesters in the nonembolized lobe was significantly elevated. No significant changes were found in nucleoside triphosphates (NTP) and Pi values. The phosphomonoester (PME) to phosphodiester (PDE) ratio in regenerating liver 48 h after partial hepatectomy was significantly greater than PME/PDE 48 h after PVE.

CONCLUSION

(31)P-MRSI is a valid technique to noninvasively evaluate cell membrane metabolism following PVE. The different degree of biochemical change between partial hepatectomy and PVE indicates that hepatic growth following these two procedures does not follow the same course.

Percutaneous transhepatic portal vein embolization: rationale, technique, and outcomes

Portal vein embolization (PVE) is used to induce preoperative liver hypertrophy in patients with anticipated marginal future liver remnant (FLR) volumes who are otherwise potential candidates for resection. PVE can be performed utilizing the transhepatic contralateral and ipsilateral approaches. The transhepatic contralateral approach is the most commonly used technique worldwide, largely owing to its technical ease. However, the contralateral approach risks injuring the FLR, thereby compromising the planned surgical resection. The transhepatic ipsilateral approach offers a potentially safer alternative because the complications associated with this approach affect only the hepatic lobe that will be resected and are usually not serious enough to preclude surgery. This article discusses PVE using the transhepatic ipsilateral and contralateral approaches, including patient selection criteria, anatomical and technical considerations, and patient complications and outcomes.

Preoperative portal venous and hepatic arterial embolization of tumor

Although the goal of embolization is usually to create therapeutic ischemia or hemostasis without surgery, the rationale for preoperative embolotherapy is different in several respects. First, the aim is to prepare patients for definitive surgical resection rather than cure or palliation, and, thus, the goals and expectations are limited and defined by close communication between the interventionalist and the surgeon. Second, when considering segmental resection, the normal liver should be protected from procedural damage. Third, the search for extrahepatic disease is crucial for these patients because resection is typically abandoned in favor of alternative therapies for patients with systemic disease. Finally, intraoperative ultrasound should always be considered to survey the future liver remnant for unsuspected small tumors and allow ablation of these lesions to maximize the success of partial hepatectomy. This article describes preoperative hepatic arterial and portal venous embolization in patients with or without cirrhosis complicated by tumors judged eligible for surgical resection or orthotopic liver transplantation (OLT). Each type of embolization will be reviewed in terms of indications and contraindications, technique, and complications. Finally, the outcomes will be evaluated in terms of morbidity, mortality, and tumor recurrence rates.

Sequential arterial and portal vein embolization in patients with cirrhosis and hepatocellular carcinoma: the hospital beaujon experience

When feasible, hepatic resection is the treatment of choice for large hepatocellular carcinoma (HCC). Because HCC is often developed on chronic liver disease, which is known to have limited regeneration capacity, major hepatic resections are often contraindicated. Portal vein embolization (PVE) has been introduced to extend the indications for major hepatic resection and to increase the safety of the surgical procedure. However, hypertrophy after PVE is often less than in normal liver. It has been suggested that preoperative sequential arterial embolization and PVE have a strong anticancer effect and could increase the rate of hypertrophy more than PVE alone. In our experience, sequential arterial embolization and PVE effectively increase the future liver remnant and induce a high rate of complete tumor necrosis. This combined procedure should broaden the indication for major resection in chronic liver disease.

Portal vein normal anatomy and variants: implication for liver surgery and portal vein embolization

The normal anatomy of the portal vein is defined as a division of the main portal vein into two branches-the left (supplying segments II, III, and IV) and right portal veins; the right dividing secondarily into two branches-the anterior (supplying segments V and VIII) and the posterior (supplying segments VI and VII) portal veins. Variants are frequent and account for 20 to 35% of the population. The most frequent variants are portal trifurcation with division of the main portal vein into the left, right anterior, and posterior branches, and the early origin of the right posterior branch directly from the portal vein. The presence of portal vein variants increases the risk of bile duct hilar anatomical variation. These variants must be diagnosed before complex hepatectomy, split or living donor transplantation, and before complex interventional procedures such as portal vein embolization. The purpose of this article is to review normal and variant portal venous anatomy and their implications for liver surgery and preoperative portal vein embolization.

Foam sclerotherapy using polidocanol (aethoxysklerol) for preoperative portal vein embolization in 16 patients

PURPOSE

To evaluate the clinical safety and effectiveness of foam sclerotherapy using polidocanol for preoperative portal vein embolization (PVE) before hemihepatectomy of the liver.

MATERIALS AND METHODS

From March 2006 to October 2008, foam sclerotherapy using polidocanol was performed in 16 patients (male-to-female ratio of 12:4, age range 48-75 years [mean 62]) for PVE. Patients were diagnosed with Klatskin tumor (n = 13), gallbladder (GB) cancer (n = 2), or hepatocellular carcinoma (HCC) (n = 1). The foam was composed of a 1:2:1 ratio of 3% polidocanol (Aethoxysklerol; Kreussler Pharma, Wiesbaden, Germany), room air, and contrast media (Xenetix 350; Guerbet, Aulnay-Sous-Bois, France). The total amount of polidocanol used (2 to 8 mL [mean 4.6]) varied according to the volume of the target portal vein. We calculated the volume of future liver remnant (FLR) before and after PVE and evaluated complications associated with the use of polidocanol foam sclerotherapy for PVE.

RESULTS

Technical success was achieved in all patients. All patients were comfortable throughout the procedure and did not experience pain during sclerotherapy. No periprocedural morbidity or mortality occurred. Patients underwent a liver dynamic computed tomography (CT) scan 2-4 weeks after PVE. FLR increased significantly after PVE using polidocanol foam from 19.3% (range 16-35%) before PVE to 27.8% (range 23-42%) after PVE (p = 0.001). All patients were operable for hemihepatectomy of the liver and achieved effective resection.

CONCLUSION

Foam sclerotherapy using polidocanol is clinically safe and effective for preoperative PVE.

Selective portal vein ligation and embolization induce different tumoral responses in the rat liver

BACKGROUND

Portal vein ligation (PVL) and portal vein embolization (PVE) are used to enhance liver volume before hepatectomy for colorectal liver metastasis (LM). Impact of such techniques on tumor growth is not well known. This experimental study aimed to assess impact of PVE and PVL on LM growth in a murine model of colorectal LM.

METHODS

Single macroscopic tumor was induced by injection of 0.5 × 10(6) DHD/K12 cells under the liver capsule of BDIX rats at day 0. Multiple microscopic tumors were obtained by intra-portal injection of 1 × 10(6) cells at day 7. At day 8, rats were divided in 3 groups: PVE group (selective 70% PVE), PVL group (selective 70% PVL); control group (sham laparotomy). Rats were sacrificed at day 37 (11 in PVE, 12 in PVL, and 10 rats in control groups). Liver volume and LM volumes were assessed.

RESULTS

Nonoccluded liver volume was larger in the PVE and PVL groups vs control group (P < .0001 and P < .0001, respectively) but showed no difference in PVE vs PVL groups (P = .08). LM volume in the occluded liver was smaller in the PVE vs control groups (P = .006) and larger in the PVL vs control groups (P = .001). LM volume in the nonoccluded liver was larger in the PVE and PVL groups vs control group (P = .010 and P = .010, respectively) but showed no difference in PVE vs PVL groups (P= .878).

CONCLUSION

Both PVL and PVE modify tumor growth, especially in nonoccluded lobe. These results could be of clinical importance in humans where both techniques are widely used.

Predictive factors for hypertrophy of the future remnant liver after selective portal vein embolization

BACKGROUND

To analyze predictive factors of hypertrophy of the nonembolized future remnant liver (FRL) after transhepatic preoperative portal vein embolization (PVE) of the liver to be resected.

MATERIALS AND METHODS

Age, gender, indocyanin green clearance test, chemotherapy before PVE, type of chemotherapy, operators, extent of PVE, radiofrequency ablation (RFA) associated with PVE, time delay between PVE and surgery, and platelet count were retrospectively evaluated as predictive factors for hypertrophy of FRL in 107 patients with malignant disease in noncirrhotic liver. PVE targeted the right liver lobe [n = 70] or the right liver lobe and segment IV [n = 37] when FRL/total liver volume ratio was below 25% in healthy liver or 40% in altered liver.

RESULTS

After PVE, FRL volume significantly increased by 69%, from 344 +/- 156 cm(3) to 543 +/- 192 cm(3) (P < .0001). The degree of hypertrophy was negatively correlated with FRL volume (correlation coefficient = -0.55, P < .0001) and FRL/TFL ratio (correlation coefficient = -0.52, P < .0001) before PVE. Patients, who have undergone chemotherapy with platin agents prior to PVE, demonstrated lower hypertrophy (P = .048).

CONCLUSION

Hypertrophy after PVE is inversely correlated to initial FRL volume. Hypertrophy of the liver might be influenced by the systemic chemotherapeutic received before PVE.