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

Safety and Effectiveness of Portal Vein Embolization after Hepatic Arterial Infusion Therapy

Portal vein embolization (PVE) is a tool potentially useful for inducing future liver remnant (FLR) hypertrophy in patients with advanced hepatic malignancies who are at high risk of hepatic insufficiency if treated with surgical resection. However, the safety and effectiveness of PVE in the context of patients who have undergone hepatic arterial infusion (HAI) are unknown. This retrospective, single-center study identified 9 patients who underwent PVE after HAI between January 2015 and December 2022. There were no major adverse events, including biliary injury or high-grade liver failure. Analysis showed an increase in standardized FLR from 21.1% (SEM ± 2.4) to 34.8% (SEM ± 2.1) over 9.8 weeks (SEM ± 1.2), with a mean kinetic growth rate of 1.9% (interquartile range, 0.9%-2.4%). Patients who have undergone HAI therapy should not be excluded from consideration of PVE as part of their operative clearance strategy.

Current Perspectives and Progress in Preoperative Portal Vein Embolization with Stem Cell Augmentation (PVESA)

Portal vein embolization with stem cell augmentation (PVESA) is an emerging approach for enhancing the growth of the liver segment that will remain after surgery (i.e., future liver remnant, FLR) in patients with liver cancer. Conventional portal vein embolization (PVE) aims to induce preoperative FLR growth, but it has a risk of failure in patients with underlying liver dysfunction and comorbid illnesses. PVESA combines PVE with stem cell therapy to potentially improve FLR size and function more effectively and efficiently. Various types of stem cells can help improve liver growth by secreting paracrine signals for hepatocyte growth or by transforming into hepatocytes. Mesenchymal stem cells (MSCs), unrestricted somatic stem cells, and small hepatocyte-like progenitor cells have been used to augment liver growth in preclinical animal models, while clinical studies have demonstrated the benefit of CD133 + bone marrow-derived MSCs and hematopoietic stem cells. These investigations have shown that PVESA is generally safe and enhances liver growth after PVE. However, optimizing the selection, collection, and application of stem cells remains crucial to maximize benefits and minimize risks. Additionally, advanced stem cell technologies, such as priming, genetic modification, and extracellular vesicle-based therapy, that could further enhance efficacy outcomes should be evaluated. Despite its potential, PVESA requires more investigations, particularly mechanistic studies that involve orthotopic animal models of liver cancer with concomitant liver injury as well as larger human trials.

Assessing regional hepatic function changes after hypertrophy induction by radioembolisation: comparison of gadoxetic acid-enhanced MRI and 99mTc-mebrofenin hepatobiliary scintigraphy

BACKGROUND

To compare Gd-ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) and 99mTc-labelled mebrofenin hepatobiliary scintigraphy (HBS) as imaging-based liver function tests after unilateral radioembolisation (RE) in patients with primary or secondary liver malignancies.

METHODS

Twenty-three patients with primary or secondary liver malignancies who underwent Gd-EOB-DTPA-enhanced MRI within a prospective study (REVoluTion) were evaluated. REVoluTion was a prospective open-label, non-randomised, therapy-optimising study of patients undergoing right-sided or sequential RE for contralateral liver hypertrophy at a single centre in Germany. MRI and hepatobiliary scintigraphy were performed before RE (baseline) and 6 weeks after (follow-up). This exploratory subanalysis compared liver enhancement on hepatobiliary phase MRI normalised to the spleen (liver-to-spleen ratio (LSR)) and the muscle (liver-to-muscle ratio (LMR)) with mebrofenin uptake on HBS for the total liver (TL) and separately for the right (RLL) and left liver lobe (LLL).

RESULTS

Mebrofenin uptake at baseline and follow-up each correlated significantly with LSR and LMR on MRI for TL (≤ 0.013) and RLL (≤ 0.049). Regarding the LLL, mebrofenin uptake correlated significantly with LMR (baseline, p = 0.013; follow-up, p = 0.004), whereas with LSR, a borderline significant correlation was only seen at follow-up (p = 0.051; p = 0.046).

CONCLUSION

LSRs and LMR correlate with mebrofenin uptake in HBS. This study indicates that Gd-EOB-DTPA-enhanced MRI and 99mTc-labelled mebrofenin HBS may equally be used to assess an increase in contralateral liver lobe function after right-sided RE.

RELEVANCE STATEMENT

MRI may be a convenient and reliable method for assessing the future liver remnant facilitating treatment planning and monitoring of patients after RE-induced hypertrophy induction.

KEY POINTS

• Both MRI and HBS can assess liver function after RE. • Liver enhancement on MRI correlates with mebrofenin uptake on HBS. • MRI might be a convenient alternative for estimating future liver remnants after hypertrophy induction.

Accidental portal vein catheterization during pleural drainage catheter insertion: a case report

BACKGROUND

Iatrogenic portal vein (PV) injuries following pleural drainage catheter (PDC) insertion are rare but life-threatening. This case report emphasizes the importance of prompt recognition and effective interventional radiology (IR) management.

CASE PRESENTATION

A 38-year-old Asian male, admitted for a non-ST-segment elevation myocardial infarction, suffered a critical PV injury during PDC insertion, leading to rapid clinical deterioration. The IR team conducted a portogram, retrieved the catheter, and successfully executed an embolization procedure. The patient's recovery, confirmed through imaging and improving liver function tests, enabled discharge with follow-up instructions.

CONCLUSIONS

This case highlights the clinical significance of promptly recognizing and effectively managing iatrogenic PV injuries during PDC insertion, with the pivotal role of IR. Collaboration between IR and surgical teams is crucial for optimizing patient outcomes.

Percutaneous radiological interventions of the portal vein: a comprehensive review

The portal vein is the largest vessel supplying the liver. A number of radiological interventions are performed through the portal vein, namely for primary pathologies of the portal vein, for inducing liver hypertrophy or to treat the sequelae of portal hypertension among others. The routes used include direct transhepatic, transjugular, and, uncommonly, trans-splenic and through subcutaneous varices. Portal vein embolization and transjugular intrahepatic portosystemic shunt are among the most common portal vein interventions that are performed to induce hypertrophy of the future liver remnant and to treat complications of portal hypertension, respectively. Other interventions include transhepatic obliteration of varices and shunts, portal vein thrombolysis, portal vein recanalization, pancreatic islet cell transplantation, and embolization of portal vein injuries. We present a detailed illustrative review of the various radiological portal vein interventions.

Portal vein embolization with absolute ethanol to induce hypertrophy of the future liver remnant

Background

Preoperative portal vein embolization (PVE) is widely used prior to major liver resection to reduce the risk of post-hepatectomy liver failure (PHLF). We evaluated the efficacy and safety of PVE using absolute ethanol.

Methods

Consecutive patients undergoing preoperative PVE between February 2003 and February 2020 at a high-volume tertiary institution were retrospectively reviewed. Hypertrophy of the future liver remnant (FLR) was determined by comparing volumetric data using semi-automated software on computed tomography or magnetic resonance imaging before and after PVE. Efficacy of absolute ethanol was evaluated by the percentage increase in the FLR volume and the ratio of the FLR to the total liver volume (TLV). Technical success and complications following PVE were evaluated. Feasibility of hepatectomy following PVE and the incidence of PHLF were determined.

Results

Sixty-two patients underwent preoperative PVE using absolute ethanol. The technical success rate was 95.2%. Median time interval between PVE and follow-up imaging was 34 days (range 6–144 days). The mean increase in FLR volume and ratio of the FLR to TLV were 43.6 ± 34.4% and 12.3 ± 7.7% respectively. Major adverse events occurred in 3 cases (4.8%) and did not preclude consideration of surgery. Forty-two patients (67.8%) proceeded to surgery for intended hepatectomy of which 36 patients (58.1%) underwent liver resection. Major post-operative complications occurred in 4 patients (11.1%) and there were no cases of PHLF.

Conclusion

Preoperative PVE with absolute ethanol is effective and safe in inducing hypertrophy of the FLR before partial hepatectomy to prevent PHLF.

Locoregional Therapy in the Management of Intrahepatic Cholangiocarcinoma: Is There Sufficient Evidence to Guide Current Clinical Practice?

PURPOSE OF REVIEW

Intrahepatic cholangiocarcinoma (iCCA) carries a dismal prognosis and, despite increasing incidence, still lacks effective treatments. In this scenario, locoregional therapies (LRT) are gaining interest as they may be effective at local tumor control and complementary to surgical and non-surgical approaches. In this article, we will review the evolving role of LRT performed by interventional radiologists in the management of iCCA.

RECENT FINDINGS

Accumulating retrospective evidence indicates that ablative therapies and transarterial embolizations are of benefit for iCCA with unresectable disease, demonstrating promising safety profiles and prolonged or comparable survival outcomes compared to systemic therapy and surgery. Additionally, for surgical candidates, portal ± hepatic venous embolization can improve the safety of hepatectomy by inducing preoperative hypertrophy of the non-involved liver lobe. LRTs are playing an increasingly important role in the multimodal treatment of iCCA from various perspectives with reduced toxicity relative to traditional treatments. To expand the scope of applications for LRTs in this setting, future prospective randomized studies are needed to confirm their efficacy and advantage.

Intensive Multimodal Therapy Combined With Long-term Temozolomide and Etoposide Treatment for Recurrent Osteosarcoma to the Liver and Stomach

The prognosis of patients with osteosarcoma recurring at extrapulmonary/extraosseous sites, especially those with unresectable tumors, is generally dismal due to high resistance to chemotherapy. The present study describes a pediatric patient with osteosarcoma recurring to the liver and stomach. Complete remission was achieved by long-term systemic chemotherapy with temozolomide+etoposide, local irradiation of the stomach, and radical surgical removal of multiple liver metastases following percutaneous transhepatic portal embolization. Second-line multimodal therapy, consisting of salvage chemotherapy and curative local treatment of metastases, may enhance disease-free survival of patients with osteosarcoma experiencing relapse to uncommon sites.

Percutaneous liver venous deprivation: outcomes in heavily pretreated metastatic colorectal cancer patients

BACKGROUND

To evaluate liver venous deprivation (LVD) outcomes in patients with colorectal liver metastasis (CRLM) heavily pretreated with systemic and hepatic arterial infusion pump (HAIP) chemotherapies that had an anticipated insufficient future liver remnant (FLR) hypertrophy after portal vein embolization (PVE).

METHODS

PVE was performed with liquid embolics using a transsplenic or ipsilateral transhepatic approach. Simultaneously and via a trans-jugular approach, the right hepatic vein was embolized with vascular plugs. Liver volumetry was assessed on computed tomography before and 3-6 weeks after LVD.

RESULTS

Twelve consecutive CRLM patients that underwent LVD before right hepatectomy or trisectionectomy were included, all previously treated with systemic chemotherapy for a mean of 11.9 months. Six patients had additional HAIP. After embolization, FLR ratio increased from 28.7% ± 5.9 to 42.2% ± 9.0 (P < 0.01). Mean kinetic growth rate (KGR) was 3.56%/week ± 2.3, with a degree of hypertrophy (DH) of 13.8% ± 7.1. In the HAIP subgroup, mean KGR and DH were respectively 3.58%/week ± 2.8 and 14.3% ± 8.7. No severe complications occurred. Ten patients reached surgery after 39 days ± 7.5.

CONCLUSION

In heavily pretreated patients, LVD safely stimulated a rapid and effective FLR hypertrophy, with a resultant high rate of resection.

Evidence on Indications and Techniques to Increase the Future Liver Remnant in Children Undergoing Extended Hepatectomy: A Systematic Review and Meta-Analysis of Individual Patient Data

BACKGROUND

Techniques to increase the future liver remnant (FLR) have fundamentally changed the indications and criteria of resectability in adult liver surgery. In pediatric patients however, these procedures have rarely been applied and the potential benefit or harm as well as suited indications are unclear.

METHODS

A systematic literature search of MEDLINE, Web of Science, and CENTRAL was conducted. Based on a PRISMA-compliant, predefined methodology, all studies reporting pediatric patients (< 18y) undergoing liver resection with either associating liver partition and portal vein ligation for stages hepatectomy (ALPPS) or preoperative portal vein embolization or ligation (PVE/PVL) were included. Baseline data, periinterventional morbidity, increase of FLR and outcomes were analyzed.

RESULTS

15 studies reporting on 21 pediatric patients with a mean age of 4 years and 7 months (range 1.8 months - 17 years) were included. 12 ALPPS procedures, 8 PVE and 1 PVL were performed. The applied criteria for performing ALPPS or PVE were heterogenous and thresholds for minimally acceptable FLR varied. Mean FLR [% of total liver volume] before the intervention was 23.6% (range 15.0 - 39.3%) in the ALPPS group and 31.4% (range 21.5 - 56.0%) in the PVE group. Mean increase of FLR before stage 2 resection was 69.4% (range 19.0 - 103.8%) for ALPPS and 62.8% (range 25.0 - 108.0%) after PVE. No postoperative death occurred, one early intrahepatic recurrence after an ALPPS procedure was reported. Overall postoperative morbidity was 23.8%.

CONCLUSION

Validated criteria for minimal FLR in pediatric liver resection are lacking and so are clear indications for ALPPS or PVE. In special cases, ALPPS and PVE can be valuable techniques to achieve complete resection of pediatric liver tumors. However, more data are needed, and future studies should focus on a definition and validation of posthepatectomy liver failure as well as the minimally needed FLR in pediatric patients undergoing extended hepatectomy.

SYSTEMATIC REVIEW REGISTRATION

[www.clinicaltrials.gov], identifier [PROSPERO 2021 CRD42021274848].

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.

Combination of transcatheter arterial chemoembolization and portal vein embolization for patients with hepatocellular carcinoma: a review

BACKGROUND

Transcatheter arterial chemoembolization has been widely used in patients with hepatocellular carcinoma. However, double blood supply and the existence of portal vein tumor thrombus influence the efficacy of transcatheter arterial chemoembolization.

MAIN BODY

Theoretically, portal vein embolization combined with transcatheter arterial chemoembolization may bring a breakthrough in the therapeutic effect of hepatocellular carcinoma. The feasibility, efficacy, long-term survival benefits, and side effects of the combined treatment have been explored in previous studies. Chemotherapeutic agents may also be added in the portal vein embolization procedure to further improve the treatment response.

CONCLUSION

In this study, we review the existing data and studies on the combined treatment in patients with hepatocellular carcinoma and provide an overall view of the strategy.

Oncological relevance of major hepatectomy with inferior vena cava resection for intrahepatic cholangiocarcinoma

BACKGROUND

This study aimed to investigate the short- and long-terms outcomes of patients undergoing major hepatectomy (MH) with inferior vena cava (IVC) resection for intrahepatic cholangiocarcinoma (ICC).

METHODS

Data from all patients who underwent MH for ICC with or without IVC resection between 2010 and 2018 were analysed retrospectively. Postoperative outcomes, overall survival (OS), and recurrence-free survival (RFS) were compared in the whole population. A propensity score matching (PSM) analysis and an inverse probability weighting analysis (IPW) were performed to assess the influence of IVC resection on short- and long-terms outcomes.

RESULTS

Among the 78 patients who underwent MH, 20 had IVC resection (IVC patients). Overall, the mortality and severe complication rate were 8% and 20%, respectively. IVC patients required more extended hepatectomies (p = 0.001) and had increased rates of transfusions (p = 0.001), however they did not experience increased postoperative morbidity, even after PSM. The 1-, 3- and 5-years OS and DFS were 78%, 45%, and 32% and 48%, 20%, and 16%, respectively. IVC was not associated with decreased OS (p = 0.52) and/or RFS (p = 0.85), even after IPW.

CONCLUSION

MH with IVC resection for ICC seems to provide acceptable short- and long-term results in a selected population of patients.

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

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

Portal Vein Embolization for Future Liver Remnant Enhancement and Combined Modality Treatment for the Management of Post-hepatic Resection Biliary Fistula in an 18-Month Old Child With Hepatoblastoma

Hepatic resection is the mainstay of treatment for hepatoblastoma. However, the presence of adequate future liver remnant (FLR) is essential to prevent postoperative liver failure. Portal vein embolization (PVE) is commonly utilized in adults for promoting hypertrophy of FLR, however, it is sparingly used in children. Secondly, bile leak after liver resections is a well-defined complication. Apart from conservative treatment such as drainage and antibiotic, several management strategies including endoscopic, percutaneous, and surgical approaches have been described for its management. We present an 18-month old child with hepatoblastoma for whom PVE was performed to enhance the FLR so that an extended right hepatectomy could be accomplished. The same patient endured delayed postoperative biliary leak wherein the conservative, and non-operative interventional procedure failed, however, surgery combined with intraoperative interventional radiology procedure was utilized with a favorable outcome.

Improving Hepatocyte Engraftment Following Hepatocyte Transplantation Using Repeated Reversible Portal Vein Embolization in Rats

Hepatocyte transplantation (HT) has emerged as a promising alternative to orthotopic liver transplantation, yet liver preconditioning is needed to promote hepatocyte engraftment. A method of temporary occlusion of the portal flow called reversible portal vein embolization (RPVE) has been demonstrated to be an efficient method of liver preconditioning. By providing an additional regenerative stimulus, repeated reversible portal vein embolization (RRPVE) could further boost liver engraftment. The aim of this study was to determine the efficiency of liver engraftment of transplanted hepatocytes after RPVE and RRPVE in a rat model. Green fluorescent protein-expressing hepatocytes were isolated from transgenic rats and transplanted into 3 groups of syngeneic recipient rats. HT was associated with RPVE in group 1, with RRPVE in group 2, and with sham embolization in the sham group. Liver engraftment was assessed at day 28 after HT on liver samples after immunostaining. Procedures were well tolerated in all groups. RRPVE resulted in increased engraftment rate in total liver parenchyma compared with RPVE (3.4% ± 0.81% versus 1.4% ± 0.34%; P < 0.001). In conclusion, RRPVE successfully enhanced hepatocyte engraftment after HT and could be helpful in the frame of failure of HT due to low cell engraftment.

Evolution in the surgical management of colorectal liver metastases: Propensity score matching analysis (PSM) on the impact of specialized multidisciplinary care across two institutional eras

BACKGROUND AND OBJECTIVES

Liver metastases are indicators of advanced disease in patients with colorectal cancer. Liver resection offers the best possibility of long-term survival. Surgical strategies have evolved in complexity in order to offer resection to a greater number of patients, requiring specialized multidisciplinary care. The current paper focused on analyzing outcomes of patients treated after the development of a dedicated cancer center in our institution.

METHODS

Patients operated on for CLM from our databank were paired through propensity score matching (PSM), and the initial experience of surgery for CLM was compared with the treatment performed after specialized multidisciplinary management. The demographic, oncological, and surgical features were analyzed between groups.

RESULTS

Overall, 355 hepatectomies were performed in 336 patients. Patients operated on during the second era of had greater use of preoperative chemotherapy (P < 0.001) as well as exposure to more effective oxaliplatin-based regimens (P < 0.001). Surgical management also changed, with minor (P = 0.002) and non-anatomic (P = 0.006) resections preferred over major operations. We also noted an increased number of minimally invasive resections (P < 0.001).

CONCLUSION

Treatment in a multidisciplinary cancer center led to changes in oncological and surgical management. Perioperative chemotherapy was frequently employed, and surgeons adopted a conservative approach to liver parenchyma.

Right trisegmentectomy after portal vein embolization in a high-risk toddler with hepatoblastoma

Portal vein embolization (PVE) is a pre-operative treatment modality in adults undergoing hepatectomy with concerns of post-operative liver failure from insufficient future liver remnant (FLR). PVE induces growth in the FLR. The success of this technique is well described in adults, but not in young children with hepatoblastoma.

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.

Liver related complications in unresectable disease after portal vein embolization

Background

Portal vein embolization (PVE) is used preoperatively in patients to increase future remnant liver volume (FRLV). Unfortunately, some patients are found to be unresectable at exploration due to tumor progression or new lesions. The aim of this study is to evaluate the long-term effects of PVE in the embolized liver lobe when left unresected.

Methods

Of 85 patients who underwent right PVE, 16 (19%) were unresectable (PVE-group). These patients were compared with 48 randomly matched patients from a pool of 75 unresectable patients who had not undergone PVE. Primary outcome parameter was occurrence of infectious complications (liver abscesses) on follow-up imaging of the liver. The long-term volumetric changes of the hypertrophy/atrophy complex were assessed as secondary outcome parameter.

Results

Five of 16 (31%) patients in PVE-group developed an abscess vs. 4 (8%) patients in non-PVE group (P=0.022). The volume distribution of left and right liver lobes (hypertrophy-atrophy rate) increased from 26%:74% before embolization to 36%:64% three weeks after PVE and to 51%:49% six months after PVE.

Conclusions

Persistence of embolized liver lobe in unresectable patients after PVE resulted in abscesses in 31%. This observation calls for developing reversible embolization techniques using absorbable materials in patients with uncertain resectability.

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.

C-Arm Cone Beam CT for Intraprocedural Image Fusion and 3D Guidance in Portal Vein Embolization (PVE)

PURPOSE

Portal vein embolization (PVE) is applied in patients with extended oncologic liver disease to induce hyperplasia of the future liver remnant and make resection feasible. Ultrasound (US) guidance is the gold standard for percutaneous portal vein access. This study evaluated feasibility and safety of C-arm cone beam computed tomography (CBCT) for needle guidance.

MATERIALS AND METHODS

In 10 patients, puncture was performed under 3D needle guidance in a CBCT data set. Contrast-enhanced (CE) CBCT was generated (n = 7), or native CBCT was registered to pre-examination CE-CT via image fusion (n = 3). Technical success, number of punctures, puncture time (time between CBCT acquisition and successful portal vein access), dose parameters and safety were evaluated. For comparison, 10 patients with PVE under US guidance were analyzed retrospectively. Study and control group were matched for age, BMI, INR, platelets, portal vein anatomy.

RESULTS

All interventions were technically successful without intervention-related complications. In the study group, the mean number of puncture attempts was 3.1 ± 2.5. Mean puncture time was 12 min (±10). Mean total dose area product (DAP) was 288 Gy cm² (±154). The mean relative share of CBCT-related radiation exposure was 6% (±3). Intervention times and DAP were slightly higher compared to the control group without reaching significance.

CONCLUSION

CBCT-guided PVE is feasible and safe. The relative dose of CBCT is low compared to the overall dose of the intervention. This technique may be a promising approach for difficult anatomic situations that limit the use of US for needle guidance.

Extreme liver resections with preservation of segment 4 only

AIM

To evaluate safety and outcomes of a new technique for extreme hepatic resections with preservation of segment 4 only.

METHODS

The new method of extreme liver resection consists of a two-stage hepatectomy. The first stage involves a right hepatectomy with middle hepatic vein preservation and induction of left lobe congestion; the second stage involves a left lobectomy. Thus, the remnant liver is represented by the segment 4 only (with or without segment 1, ± S1). Five patients underwent the new two-stage hepatectomy (congestion group). Data from volumetric assessment made before the second stage was compared with that of 10 matched patients (comparison group) that underwent a single-stage right hepatectomy with middle hepatic vein preservation.

RESULTS

The two stages of the procedure were successfully carried out on all 5 patients. For the congestion group, the overall volume of the left hemiliver had increased 103% (mean increase from 438 mL to 890 mL) at 4 wk after the first stage of the procedure. Hypertrophy of the future liver remnant (i.e., segment 4 ± S1) was higher than that of segments 2 and 3 (144% vs 54%, respectively, P < 0.05). The median remnant liver volume-to-body weight ratio was 0.3 (range, 0.28-0.40) before the first stage and 0.8 (range, 0.45-0.97) before the second stage. For the comparison group, the rate of hypertrophy of the left liver after right hepatectomy with middle hepatic vein preservation was 116% ± 34%. Hypertrophy rates of segments 2 and 3 (123% ± 47%) and of segment 4 (108% ± 60%, P > 0.05) were proportional. The mean preoperative volume of segments 2 and 3 was 256 ± 64 cc and increased to 572 ± 257 cc after right hepatectomy. Mean preoperative volume of segment 4 increased from 211 ± 75 cc to 439 ± 180 cc after surgery.

CONCLUSION

The proposed method for extreme hepatectomy with preservation of segment 4 only represents a technique that could allow complete resection of multiple bilateral liver metastases.

FIRST BRAZILIAN CONSENSUS ON MULTIMODAL TREATMENT OF COLORECTAL LIVER METASTASES. MODULE 1: PRE-TREATMENT EVALUATION

Background

: Liver metastases of colorectal cancer are frequent and potentially fatal event in the evolution of patients with these tumors.

Aim

: In this module, was contextualized the clinical situations and parameterized epidemiological data and results of the various treatment modalities established.

Method:

Was realized deep discussion on detecting and staging metastatic colorectal cancer, as well as employment of imaging methods in the evaluation of response to instituted systemic therapy.

Results

: The next step was based on the definition of which patients would have their metastases considered resectable and how to expand the amount of patients elegible for modalities with curative intent.

Conclusion

: Were presented clinical, pathological and molecular prognostic factors, validated to be taken into account in clinical practice.

Transcatheter Arterial Embolization for Hepatic Arterial Injury Related to Percutaneous Transhepatic Portal Intervention

PURPOSE

To assess the usefulness of transcatheter arterial embolization (TAE) for the hepatic arterial injury related to percutaneous transhepatic portal intervention (PTPI).

MATERIALS AND METHODS

Fifty-four patients, 32 males and 22 females with a median age of 68 years (range 43-82 years), underwent PTPI. The procedures consisted of 33 percutaneous transhepatic portal vein embolizations, 19 percutaneous transhepatic variceal embolizations, and 2 percutaneous transhepatic portal venous stent placements. Two patients with gastric varices underwent percutaneous transhepatic variceal embolization twice because of recurrence. Therefore, the total number of procedures was 56. Among them, hepatic arterial injury occurred in 6 PTPIs in 5 patients, and TAE was performed. We assessed technical success, complications related to TAE, and clinical outcome. Technical success was defined as the disappearance of findings due to hepatic arterial injury on digital subtraction angiography.

RESULTS

As hepatic arterial injuries, 4 extravasations and 2 arterioportal shunts developed. All TAEs were performed successfully. The technical success rate was 100 %. Complication of TAE occurred in 5 of 6 TAEs; 3 were focal liver infarction, not requiring further treatment, and 2 were biloma that required percutaneous drainage. Five TAEs in 4 patients were performed immediately after the PTPI, and these 4 patients were alive. However, one TAE was performed 10 h later, and the patient died due to multiple organ failure 2 months later although TAE was successful.

CONCLUSION

TAE is a useful treatment for hepatic arterial injury related to PTPI. However, it should be performed at an early stage.

Clinical implications for imaging of vascular invasion in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the second largest cause of cancer mortality in the world, with vascular invasion being one of the most important prognostic factors. HCC with tumor thrombus was traditionally considered to have very limited treatment options. However, multiple promising treatment strategies have emerged in recent years, with diagnostic and interventional radiologists playing a major role in patient management. We provide a comprehensive update on the diagnosis and management of HCC with vascular invasion and the role of the radiologist in this condition.

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.

Controversies of preoperative portal vein embolization

Portal vein embolization (PVE) is a safe, percutaneous procedure that has been proven to lower the complication rates of curative intent large-volume hepatic resection by inducing hypertrophy of the future liver remnant. While the safety and efficacy of PVE has been well substantiated, there remains controversy with regards to the technical details, periprocedural management, and whether alternative methods of achieving future liver remnant hypertrophy are preferable to PVE. This paper will address those controversies and offer recommendations based on available data.

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.

Preliminary study on liver function changes after trisectionectomy with versus without prior portal vein embolization

PURPOSE

Post-hepatectomy liver failure (PHLF) is the major risk factor for mortality after hepatectomy. Preoperative planning of the future liver remnant volume reduces PHLF rates; however, future liver remnant function (FLR-F) might have an even stronger predictive value. In this preliminary study, we used a new method to calculate FLR-F by the LiMAx test and computer tomography-assisted volumetric-analysis to visualize liver function changes after portal vein embolization (PVE) before extended hepatectomy.

METHODS

The subjects included patients undergoing extended right hepatectomy either directly (NO-PVE group) or after PVE (PVE group). Computed tomography (CT) scan and liver function tests (LiMAx) were done before PVE and preoperatively. FLR-F was calculated and correlated with the postoperative liver function.

RESULTS

There were 12 patients in the NO-PVE group and 19 patients in the PVE group. FLR-F and postoperative liver function correlated significantly in both groups (p = 0.036, p = 0.011), although postoperative liver function was slightly overestimated, at 32 and 45 µg/kg/min, in the NO-PVE and PVE groups, respectively. LiMAx value did not change after PVE.

CONCLUSIONS

Volume-function analysis using LiMAx and CT scan enables us to reliably predict early postoperative liver function. Global enzymatic liver function measured by the LiMAx test did not change after PVE, confirming that liver function distribution in the liver stays constant after PVE. An overestimation of FLR-F is needed to compensate for the intraoperative liver injury that occurs in patients undergoing extended hepatectomy.

Portal Vein Embolization Before Extended Hepatectomy in a Toddler With Mesenchymal Hamartoma

Portal vein embolization is widely used to induce hypertrophy of the future liver remnant before extended hepatectomy, decreasing the risk of postoperative liver failure. However, this percutaneous procedure has not been previously reported in a young child. The present report describes the case of a 14-month-old patient with a large multifocal mesenchymal hamartoma of the entire right liver, successfully resected after induction of future liver remnant hypertrophy by portal vein embolization.

Complications of Portal Vein Embolization: Evaluation on Cross-Sectional Imaging

Portal vein embolization (PVE) is known as an effective and safe preoperative procedure that increases the future liver remnant (FLR) in patients with insufficient FLR. However, some possible major complications can lead to non-resectability or delayed elective surgery that results in increased morbidity and mortality. Although the majority of these complications are rare, knowledge of the radiologic findings of post-procedural complications facilitate an accurate diagnosis and ensure prompt management. We accordingly reviewed the CT findings of the complications of PVE.

Clearing the Confusion over Hepatic Encephalopathy After TIPS Creation: Incidence, Prognostic Factors, and Clinical Outcomes

PURPOSE

To assess the incidence, prognostic factors, and clinical outcomes of hepatic encephalopathy (HE) after transjugular intrahepatic portosystemic shunt (TIPS) creation.

MATERIALS AND METHODS

In this single-institution retrospective study, 191 patients (m:f = 114:77, median age 54 years, median Model for End-Stage Liver Disease or MELD score 14) who underwent TIPS creation between 1999 and 2013 were studied. Medical record review was used to identify demographic characteristics, liver disease, procedure, and outcome data. Post-TIPS HE within 30 days was defined by new mental status changes and was graded according to the West Haven classification system. The influence of data parameters on HE occurrence and 90-day mortality was assessed using binary logistic regression.

RESULTS

TIPS was successfully created with hemodynamic success in 99 % of cases. Median final PSG was 7 mmHg. HE incidence within 30 days was 42 % (81/191; 22 % de novo, 12 % stable, and 8 % worsening). Degrees of HE included grade 1 (46 %), grade 2 (29 %), grade 3 (18 %), and grade 4 (7 %). Medical therapy typically addressed HE, and shunt reduction was necessary in only three cases. MELD score (P = 0.020) and age (P = 0.009) were significantly associated with HE development on multivariate analysis. Occurrence of de novo HE post-TIPS did not associate with 90-day mortality (P = 0.400), in contrast to worsening HE (P < 0.001).

CONCLUSIONS

The incidence of post-TIPS HE is non-trivial, but symptoms are typically mild and medically managed. HE rates are higher in older patients and those with worse liver function and should be contemplated when counseling on expected TIPS outcomes and post-procedure course.

Image-guided interventions in oncology

Interventional oncology, a term commonly used to indicate the minimally invasive procedures performed by interventional radiologists to diagnose and manage cancer, encompasses a broad spectrum of techniques unique to interventional radiology that have been established as a vital part of the multidisciplinary oncologic cancer care team. This article provides an updated overview of the variety of applications of image-guided procedures to distinct clinical scenarios, such as the diagnosis, treatment, and management of complications of malignancies.

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.

Improved hypertrophy of future remnant liver after portal vein embolization with plugs, coils and particles

PURPOSE

To retrospectively analyze efficacy as measured by volume gain of future remnant liver (FRL) after right portal vein embolization (PVE) using particles only versus particles and additional central plug and/or coil (CP/C) embolization.

METHODS

All patients who underwent PVE between July 2011 and December 2012 were retrospectively analyzed. Right PVE was performed either with particle-only (PO) embolization or additional CP/C embolization. All enrolled patients underwent computed tomography or magnetic resonance imaging before PVE and surgery. The images were used for volumetry of the FRL.

RESULTS

Of 75 patients, 40 had PO and 35 CP/C embolization. Age, sex, and tumor entities did not differ significantly between the two groups. Tumor entities included cholangiocarcinoma (n = 52), metastasis from colorectal cancer (n = 14), hepatocellular carcinoma (n = 2), and others (n = 7). Time from PVE to preoperative imaging was similar in both groups. FRL volume before PVE was 329 ± 121 ml in the PO group and 333 ± 135 ml in the CP/C group, and 419 ± 135 ml and 492 ± 165 ml before operation. The average percentage volume gain was significantly higher in the CP/C group than in the PO group, with 53.3 ± 34.5 % versus 30.9 ± 28.8 % (p = 0.002).

CONCLUSION

Right PVE with additional CP/C embolization leads to a significantly higher gain in FRL volume than embolization with particles alone.