Ipsilateral percutaneous transhepatic portal vein embolization with gelatin sponge particles and coils in preparation for extended right hepatectomy for hilar cholangiocarcinoma

The Guidelines for Percutaneous Transhepatic Portal Vein Embolization: English Version

Preoperative portal vein embolization is a beneficial option to reduce the risk of postoperative liver failure by promoting the growth of the future liver remnant. In particular, a percutaneous transhepatic procedure (percutaneous transhepatic portal vein embolization) has been developed as a less-invasive approach. Although percutaneous transhepatic portal vein embolization is widely recognized as a safe procedure, various complications, including rare but fatal adverse events, have been reported. Currently, there are no prospective clinical trials regarding percutaneous transhepatic portal vein embolization procedures and no standard guidelines for the PTPE procedure in Japan. As a result, various methods and various embolic materials are used in each hospital according to each physician's policy. The purpose of these guidelines is to propose appropriate techniques at present and to identify issues that should be addressed in the future for safer and more reliable percutaneous transhepatic portal vein embolization techniques.

Interventions for unresectable intrahepatic cholangiocarcinoma: a network meta‐analysis

This is a protocol for a Cochrane Review (intervention). The objectives are as follows:

To establish the existence of differences in effectiveness and safety of intra‐arterial therapies (IATs) such as bland embolisation, conventional transarterial chemoembolisation (cTACE), drug‐eluting bead transarterial chemoembolisation (DEBTACE), yttrium‐90 (Y90), hepatic artery infusion (HAI), external beam radiotherapies (EBRTs), and immunotherapy versus systemic chemotherapy for unresectable intrahepatic cholangiocarcinoma through pairwise meta‐analysis and network meta‐analysis with subsequent treatment ranking.

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.

Future Liver Remnant Indocyanine Green Plasma Clearance Rate as a Predictor of Post-hepatectomy Liver Failure After Portal Vein Embolization

PURPOSE

To evaluate the utility of future liver remnant plasma clearance rate of indocyanine green (ICGK-F) for predicting post-hepatectomy liver failure (PHLF) compared with percentage future liver remnant volume-to-total liver volume ratio (%FLR) after portal vein embolization (PVE).

MATERIALS AND METHODS

PVE procedures in 20 patients (15 patients underwent PVE with absolute ethanol; 5 patients with gelatin particles) from 2010 to 2017 were analyzed. %FLR = future liver remnant volume (ml)/[total liver volume (ml) - tumor volume (ml)] × 100; ICGK-F = plasma clearance rate of indocyanine green (ICGK) × %FLR/100 were calculated before and after PVE. PHLF was categorized according to the criteria of the International Study Group of Liver Surgery. For predicting PHLF, we compared the ICGK-F and %FLR after PVE between the grade A PHLF group and the non-grade A PHLF (grades B and C) group.

RESULTS

All PVE procedures were successful. While the ICGK-F of the grade A PHLF group (median 0.073, n = 16) was about twice that of the non-grade A PHLF group (median 0.043, n = 4), showing a significant difference (Mann-Whitney U test: P = 0.002), there was no significant difference in %FLR between the grade A PHLF group and the non-grade A PHLF group (Mann-Whitney U test: P = 0.335).

CONCLUSION

ICGK-F was significantly higher in the grade A PHLF group than in the non-grade A PHLF group (grades B and C), and ICGK-F was more useful for predicting PHLF than %FLR.

Efficacy of percutaneous transhepatic portal vein embolization using gelatin sponge particles and metal coils

Background

Percutaneous transhepatic portal vein embolization (PTPE) can increase the future liver remnant (FLR) volume before extended liver resection; however, there is no current consensus regarding the best embolic material for PTPE.

Purpose

To evaluate the efficacy of PTPE using gelatin sponge particles and coils.

Material and Methods

The medical records of 136 patients who underwent PTPE using gelatin sponge particles and metal coils were retrospectively reviewed. We evaluated the procedural details, liver volume on CT, and clinical status before and after PTPE.

Results

The mean FLR volume increased significantly from 390 ± 147 cm³ to 508 ± 141 cm³ (P < 0.001). A mean of 22.1 ± 9.4 days after PTPE, the mean increase in the ratio of FLR volume to total liver volume was 9.4 ± 6.5%. Complications related to PTPE occurred in five patients, including arterial damage (n = 4) and biloma (n = 1). The white blood cell count and C-reactive protein level increased significantly and then returned to baseline within seven days. Aspartate aminotransferase and alanine aminotransferase showed no significant changes. Fever (defined by the Common Terminology Criteria for Adverse Events v4.0) was reported in 74 patients (54%), but it was generally mild (Grade 1/2; n = 72). None of the patients experienced severe complications that required cancellation of surgery.

Conclusion

PTPE with gelatin sponge particles and coils may impose low physical stress on patients and is a safe method of inducing a significant increase of FLR.

Meta-analysis of associating liver partition with portal vein ligation and portal vein occlusion for two-stage hepatectomy

BACKGROUND

Discussion is ongoing regarding whether associating liver partition with portal vein ligation for staged hepatectomy (ALPPS) or portal vein occlusion is better in staged hepatectomy. The aim of this study was to compare available strategies using a two-stage approach in extended hepatectomy.

METHODS

A literature search was performed in MEDLINE, Scopus, the Cochrane Library and Embase, and additional articles were identified by hand searching. Data from the international ALPPS registry were extracted. Clinical studies reporting volumetric changes, mortality, morbidity, feasibility of the second stage and tumour-free resection margins (R0) in two-stage hepatectomy were included.

RESULTS

Ninety studies involving 4352 patients, including 320 from the ALPPS registry, met the inclusion criteria. Among these, nine studies (357 patients) reported on comparisons with other strategies. In the comparison of ALPPS versus portal vein embolization (PVE), ALPPS was associated with a greater increase in the future liver remnant (76 versus 37 per cent; P < 0·001) and more frequent completion of stage 2 (100 versus 77 per cent; P < 0·001). Compared with PVE, ALPPS had a trend towards higher morbidity (73 versus 59 per cent; P = 0·16) and mortality (14 versus 7 per cent; P = 0·19) after stage 2. In the non-comparative studies, complication rates were 39 per cent in the PVE group, 47 per cent in the portal vein ligation (PVL) group and 70 per cent in the ALPPS group. After stage 2, mortality rates were 5, 7 and 12 per cent respectively.

CONCLUSION

ALPPS is associated with greater future liver remnant hypertrophy and a higher rate of completion of stage 2, but this may be at the price of greater morbidity and mortality.

Guidelines on the use of gelatin sponge particles in embolotherapy

Gelatin sponge (GS) is one of the most widely used embolic agents in interventional procedures. There are four commercially available GS products in Japan; however, the endovascular use of Gelfoam and Spongel is off-label, and Gelpart can only be used for hepatic artery embolization and Serescue can only be used for hemostasis of arterial bleeding. GS has been used for a variety of clinical indications, mainly tumor embolization and stopping massive arterial bleeding. The optimal size and preparation procedure of GS particles differs slightly for each clinical indication. In addition, there is a risk of ischemic and/or infectious complications associated with GS embolization in various situations. Therefore, radiologists should be familiar with not only the preparation and handling of GS particles, but also the disadvantages and potential risks, in order to perform GS embolization safely and effectively.

A review of the clinical diagnosis and therapy of cholangiocarcinoma

Cholangiocarcinoma (CCA) is the second most common primary hepatic malignancy worldwide. The incidence of intrahepatic CCA is increasing, whereas that of extrahepatic CCA is decreasing. This review looks at the new advances that have been made in the management of CCA, based on a PubMed and Science Citation Index search of results from randomized controlled trials, reviews, and cohort, prospective and retrospective studies. Aggressive interventional approaches and new histopathological techniques have been developed to make a histological diagnosis in patients with high risk factors or suspected CCA. Resectability of the tumour can now be assessed using multiple radiological imaging studies; the main prognostic factor after surgery is a histologically negative resection margin. Biliary drainage and/or portal vein embolization may be performed before extended radical resection, or liver transplantation may be undertaken in combination with neoadjuvant chemotherapy or chemoradiotherapy. Though many advances have been made in the management of CCA, the standard modality of treatment has not yet been established. This review focuses on the clinical options for different stages of CCA.

Does preoperative portal vein embolization have any impact on the outcome of right-side hepatectomy for Klatskin tumor?

BACKGROUND AND AIM

The clinical usefulness of portal vein embolization (PVE) for Klatskin tumor is not well established. The authors explored the change in liver volume and function before and after major hepatectomy and evaluated the effect of PVE.

METHODS

Thirty-three consecutive patients who underwent right hepatectomy with an initial future liver remnant (FLR) ≤ 30% for Klatskin tumors at Seoul National University Hospital were included.

RESULTS

Eleven patients underwent PVE, and eight patients received right trisectionectomy. PVE induced a mean FLR increase of 19.3% after a mean of 15.8 days. At postoperative month 1, liver volume and liver hypertrophy ratio was comparable between PVE and no-PVE group. For patients with an initial FLR ≤ 20%, postoperative liver hypertrophy rate of PVE group was comparable to no-PVE group. Liver function tests were not affected by PVE or the initial FLR. Postoperative liver hypertrophy ratio was negatively correlated with the initial FLR (hypertrophy ratio (%) = 326.7-0.4×initial FLR (ml), P = 0.001). There was no severe PVE-related morbidity, and postoperative morbidity rate was comparable in PVE and no-PVE group.

CONCLUSION

The postoperative liver hypertrophy ratio, final liver volume, or liver function tests were not affected by PVE. Postoperative liver hypertrophy was related to the initial FLR.

Portal vein embolization before liver resection: a systematic review

Purpose

This is a review of literature on the indications, technique, and outcome of portal vein embolization (PVE).

Methods

A systematic literature search on outcome of PVE from 1990 to 2011 was performed in Medline, Cochrane, and Embase databases.

Results

Forty-four articles were selected, including 1,791 patients with a mean age of 61 ± 4.1 years. Overall technical success rate was 99.3 %. The mean hypertrophy rate of the FRL after PVE was 37.9 ± 0.1 %. In 70 patients (3.9 %), surgery was not performed because of failure of PVE (clinical success rate 96.1 %). In 51 patients (2.8 %), the hypertrophy response was insufficient to perform liver resection. In the other 17 cases, 12 did not technically succeed (0.7 %) and 7 caused a complication leading to unresectability (0.4 %). In 6.1 %, resection was cancelled because of local tumor progression after PVE. Major complications were seen in 2.5 %, and the mortality rate was 0.1 %. A head-to-head comparison shows a negative effect of liver cirrhosis on hypertrophy response. The use of n-butyl cyanoacrylate seems to have a greater effect on hypertrophy, but the difference with other embolization materials did not reach statistical significance. No difference in regeneration is seen in patients with cholestasis or chemotherapy.

Conclusions

Preoperative PVE has a high technical and clinical success rate. Liver cirrhosis has a negative effect on regeneration, but cholestasis and chemotherapy do not seem to have an influence on the hypertrophy response. The use of n-butyl cyanoacrylate may result in a greater hypertrophy response compared with other embolization materials used.

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.

Portal vein embolization: rationale, outcomes, controversies and future directions

Portal vein embolization (PVE) is now considered the standard of care to improve safety for patients undergoing extensive hepatectomy with an anticipated small future liver remnant (FLR). PVE is used to induce contralateral liver hypertrophy in preparation for major liver resection. Optimal patient selection is essential to maximize the clinical benefits of PVE. Computed tomography volumetry is used to calculate a standardized FLR and determine the need for preoperative PVE. Percutaneous PVE can be performed via the transhepatic ipsilateral or contralateral approaches, depending on operator preference. Several different embolic agents are available to the interventional radiologist, all with similar effectiveness in inducing hypertrophy. When an extended hepatectomy is planned, right PVE should include segment 4, in order to maximize FLR hypertrophy. Multiple studies have demonstrated the beneficial outcomes of PVE in both patients with healthy livers and with underlying liver diseases. Novel improvements to PVE should expand its scope to patients who were previously not candidates for the procedure.

Volumetric analysis of the liver after right portal vein embolization: mid-term follow-up based on embolization score

AIM

To evaluate liver volume alterations and liver function after right portal vein embolization (PVE) during mid-term follow-up based on embolization score.

MATERIALS AND METHODS

Computed tomography (CT) images and liver function profiles were obtained before PVE, and at short-term (7-45 days), and mid-term follow-up (106-380 days) after PVE in all 30 patients. The patients were divided into group A (PVE score >or=3, n=20) and group B (PVE score <3, n=10). High score indicates more complete embolization.

RESULTS

Left liver volume (LLV) and percentage future liver remnant (%FLR) increased significantly between pre-PVE and short-term follow-up and between short-term and mid-term follow-up in group A. Increase in FLR volume was significantly higher at the mid-term follow-up than at the short-term follow-up in group A. The ratio of embolized to total liver volume (RETLV) on short-term follow-up was significantly higher in group A than in group B. Aspartate transaminase (AST) and alanine transaminase (ALT) were elevated on short-term follow-up, whereas at mid-term follow-up in group A, they had significantly returned to the baselines.

CONCLUSION

PVE resulted in continued compensatory hypertrophy of the unembolized liver during the 6-month follow-up. Compensatory hypertrophy in the unembolized liver was proportional to the ratio of embolization and to the embolized liver volume.

Preoperative portal vein embolization using an amplatzer vascular plug

The purpose was to evaluate the safety and efficacy of preoperative portal vein embolization (PVE) using an Amplatzer vascular plug (AVP). Forty-one patients who underwent PVE using gelatin sponge particles and the AVP were enrolled. The right portal branches were embolized using gelatin sponges (1-8 mm(3)) through a 5-F catheter, and the AVP was deployed at the first- or second-order right portal vein. Technical success and complications, recanalization, and changes of total estimated liver volumes (TELV), future liver remnant (FLR), and FLR/TELV were evaluated. Follow-up CT performed 6-43 days (median, 16 days) after PVE was used to evaluate volume parameters. PVE was technically successful in 40 of 41 patients. Major complications occurred in two patients, with one each having extensive portal vein thrombosis and liver abscess. Partial recanalization of the occluded portal vein was seen in one patient. The mean FLR volume (653 +/- 174 ml vs. 532 +/- 154 ml, p < 0.001) and mean FLR/TELV ratio (43 +/- 8% vs 36 +/- 7%, p < 0.001) were significantly higher after than before PVE. PVE using the AVP seems to be a relatively safe and effective technique for inducing hypertrophy of the FLR with minimal risk of recanalization.

Present status and future perspectives of preoperative portal vein embolization

BACKGROUND

Portal vein embolization (PVE) has been gaining increasing acceptance before major hepatectomy. This review presents the application, outcome, and recent developments of PVE.

METHODS

After a systematic search of "portal vein embolization" in PubMed, we reviewed and retrieved articles written in English related to PVE. There were no other criteria for exclusion of published information pertaining to this topic.

RESULTS

Hypertrophy of future liver remnants with PVE in patients with hepatobiliary malignancy results in fewer complications and shorter hospital stays after major hepatectomy, and add to the pool of candidates for surgical treatment. Some new techniques, such as sequential hepatic artery-portal vein embolization and PVE with stem cell administration, have showed a promising clinical future.

CONCLUSIONS

PVE has achieved significant improvement in the outcome of major hepatectomy, and has enlarged the candidate pool of liver resection as well. Future study is needed to identify the precise mechanism of liver regeneration after PVE.

Liver regeneration and recanalization time course following reversible portal vein embolization

BACKGROUND/AIMS

Permanent portal vein embolization (PVE) is a widely practised technique. The use of an absorbable material would be safer in clinical situations in which the embolized liver is not resected. We evaluated the efficiency of reversible PVE in terms of liver regeneration and analyzed the precise time course of portal recanalization.

METHODS

Nine monkeys underwent PVE of the left and right anterior portal branches using powdered absorbable material. Repeated portograms were carried out until complete revascularization of the embolized liver. Hepatocyte proliferation rates were assessed by BrdU incorporation. Liver segment volumes were determined by CT scans performed before embolization, then 1 month and 1 year after embolization.

RESULTS

Reversible PVE induced significant hepatocyte proliferation in the non-embolized segments (13.5+/-1.0%, 10.5+/-0.8% and 9.1+/-2.0% of cells on days 3, 5 and 7, respectively). One month after the embolization, the non-embolized liver volume had increased from 38.4+/-1.3% to 54.8+/-0.5% of total liver volume. Proximal and complete revascularization occurred 6-8 and 12-16 days, respectively.

CONCLUSIONS

Reversible PVE efficiently induces liver regeneration. The use of absorbable material avoids long-term liver scarring. Such material may be suitable for several clinical indications, including cell transplantation.