Complications of percutaneous transhepatic portal vein embolization

Vascular Interventions in Oncology

Vascular interventions are an important and established tool in the management of the oncology patient. The goal of these procedures may be curative, palliative or adjunctive in nature. Some of the common vascular interventions used in oncology include transarterial embolisation or chemoembolisation, selective internal radiation therapy, chemosaturation, venous access lines, superior vena cava stenting and portal vein embolisation. We provide an overview of the principles, technology and approach of vascular techniques for tumour therapy in both the arterial and venous systems. Arterial interventions are currently mainly used in the management of hepatocellular carcinoma. Transarterial embolisation, chemoembolisation and selective internal radiation therapy deliver targeted catheter-delivered treatments with the aim of reducing tumour burden, controlling tumour growth or increasing survival in patients not eligible for transplantation. Chemosaturation is a regional chemotherapy technique that delivers high doses of chemotherapy directly to the liver via the hepatic artery, while reducing the risks of systemic effects. Venous interventions are more adjunctive in nature. Venous access lines are used to provide a means of delivering chemotherapy and other medications directly into the bloodstream. Superior vena cava stenting is a palliative procedure that is used to relieve symptoms of superior vena cava obstruction. Portal vein embolisation is a procedure that allows hypertrophy of a healthy portion of the liver in preparation for liver resection. Interventional radiology-led vascular interventions play an essential part of cancer management. These procedures are minimally invasive and provide a safe and effective adjunct to traditional cancer treatment methods. Appropriate work-up and discussion of each patient-specific problem in a multidisciplinary setting with interventional radiology is essential to provide optimum patient-centred care.

Image-guided percutaneous strategies to improve the resectability of HCC: Portal vein embolization, liver venous deprivation, or radiation lobectomy?

Despite considerable advances in surgical technique, many patients with hepatic malignancies are not operative candidates due to projected inadequate hepatic function following resection. Consequently, the size of the future liver remnant (FLR) is an essential consideration when predicting a patient's likelihood of liver insufficiency following hepatectomy. Since its initial description 30 years ago, portal vein embolization has become the standard of care for augmenting the size and function of the FLR preoperatively. However, new minimally invasive techniques have been developed to improve surgical candidacy, chief among them liver venous deprivation and radiation lobectomy. The purpose of this review is to discuss the status of preoperative liver augmentation prior to resection of hepatocellular carcinoma with a focus on these three techniques, highlighting the distinctions between them and suggesting directions for future investigation.

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.

Hepatic hemodynamic study: More than just HVPG measurement

Evaluation and staging of liver disease is essential in the clinical decision-making process of liver tumors. The severity of portal hypertension (PH) is the main prognostic factor in advanced liver disease. Performing an accurate hepatic venous pressure gradient (HVPG) measurement is not always possible, especially when veno-venous communications are present. In those complex cases, a refinement in HVPG measurement with a thorough evaluation of each of the components of PH is mandatory. We aimed at describing how some technical modifications and complementary procedures may contribute to an accurate and complete clinical evaluation to improve therapeutic decisions.

Simultaneous robot-assisted colorectal surgery for sigmoid colon cancer and portal vein embolization from the inferior mesenteric vein for intrahepatic cholangiocarcinoma: A case report and literature review

INTRODUCTION AND IMPORTANCE

The treatment of multiple cancers requires multidisciplinary expertise. In this case, we experienced a multiple cancers case, sigmoid colon cancer and intrahepatic cholangiocarcinoma that required preoperative portal vein embolization (PVE). PVE is often approached by trans-hepatic percutaneous approach or via ileocecal vein (ICV) or veins of the small intestine. In this case, the patient was scheduled to undergo robot-assist surgery for sigmoid colon cancer, and it was planned that the inferior mesenteric vein (IMV) would be cut. PVE from the IMV was performed with hope to reduce complications.

CASE PRESENTATION

This patient had intrahepatic cholangiocarcinoma and sigmoid colon cancer. A radical cure for intrahepatic cholangiocarcinoma was expected by left liver lobectomy. Because of concerns about postoperative liver failure, it was decided to perform PVE. PVE via IMV approach was performed simultaneously with robot-assisted surgery for sigmoid colon cancer. The patient was discharged without complications 12 days after surgery.

CLINICAL DISCUSSION

PVE is a very important technique for massive hepatic resection. Percutaneous trans-hepatic approach has the potential to damage vessels, bile duct, normal liver. Venous approaches, including via ICV, have the potential to damage vessels. In this case, we performed PVE from the IMV because we thought this approach would reduce the risk of complications. The patient successfully underwent PVE without complications.

CONCLUSION

PVE via IMV was successfully performed without complications. In multiple cancers case, this approach would be better approach than any other PVE approach like this case.

Surgery

This chapter provides a comprehensive background from basic to applied knowledge of surgical anatomy which is necessary for the surgical treatment of cholangiocarcinoma (CCA) patients. Significant advances that have been made in the surgical treatment of CCA were examined. For instance, in-depth details are provided for appropriate preoperative assessment and treatment to optimize patient status and to improve the outcome of surgical treatment(s). Comprehensive details are provided for the surgical techniques and outcomes of treatments for each type of CCA with clear illustrations and images. This chapter also describes the role of minimally invasive surgery and liver transplantation in CCA treatment.

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.

Promoting Surgical Resection through Future Liver Remnant Hypertrophy

An inadequate future liver remnant (FLR) can preclude curative-intent surgical resection for patients with primary or secondary hepatic malignancies. For patients with normal baseline liver function and without risk factors, an FLR of 20% is needed to maintain postsurgical hepatic function. However, the FLR requirement is higher for patients who are exposed to systemic chemotherapy (FLR, >30%) or have cirrhosis (FLR, >40%). Interventional radiologic and surgical methods to achieve FLR hypertrophy are evolving, including portal vein ligation, portal vein embolization, radiation lobectomy, hepatic venous deprivation, and associating liver partition and portal vein ligation for staged hepatectomy. Each technique offers particular advantages and disadvantages. Knowledge of these procedures can help clinicians to choose the suitable technique for each patient. The authors review the techniques used to develop FLR hypertrophy, focusing on technical considerations, outcomes, and the advantages and disadvantages of each approach. Online supplemental material is available for this article. ^©RSNA, 2022.

Portal vein embolization via the ipsilateral percutaneous transhepatic approach versus laparotomic transileocecal approach: complications, profile and changes in future liver remnant volume

OBJECTIVE

Major liver resection is an effective treatment option for patients with liver malignancy. The future liver remnant (FLR) volume and complications after portal vein embolization (PVE) were compared between the ipsilateral right portal vein (PTPE) and transileocolic (TIPE) approaches.

METHODS

A total of 42 patients (TIPE, n = 22; PTPE, n = 20) underwent right lobectomy after PVE. CT and hepatobiliary scintigraphy were repeated before and after PVE. The blood examination findings and the FLR values (FLRCT: calculated from CT, %FLRCT: FLRCT ratio, %FLRSPECT: FLR ratio using single photon emission CT, FLRCT/BS: FLRCT to body surface ratio) were compared between two approach sites. The complications and mortality were also analyzed after PVE and major right hepatectomy.

RESULTS

There were no significant differences in the patient characteristics, blood examination findings or FLR values between two groups. Adequate liver regeneration was observed without significant differences between PTPE and TIPE (increased ratio of FLRCT: 8.7% vs 19.2%, p = 0.15 [25-75 percentile: 17.1-60.4], %FLRCT: 11.2% vs 8.3%, p = 0.25 [6.3-13.3], %FLRSPECT: 15.4% vs 19.2%, p = 0.09 [16.0-22.4], FLRCT/BS: 33.6% vs 47.1%, p = 0.19 [17.2-60.4], respectively), but TIPE required a significantly longer procedure time than PTPE [181.4 min vs 108.7 min, p < 0.01 (103.3-193.5)]. However, one patient was converted to TIPE due to bleeding during PTPE. After right lobectomy, portal vein stenosis or thrombosis was noted in three patients [two with TIPE (9.1%) and one with PTPE (5%)] and three TIPE patients died within 90 days (13.6%) after right hepatectomy.

CONCLUSION

FLR volume significantly increased after PVE, regardless of the approach sites; however, PTPE is a useful technique with a shorter procedure time.

Transcatheter arterial embolization of iatrogenic massive arterioportal fistula in the liver

BACKGROUND

Massive arterioportal fistula (APF) is naturally irreversible and can induce portal hypertension and portal vein thrombosis (PVT), worsening survival outcomes.

PURPOSE

To evaluate the clinical course and details of transarterial embolization (TAE) procedures for massive APF.

MATERIAL AND METHODS

This retrospective single-center observational study evaluated the time until embolization after puncture, imaging, embolization methods, and laboratory data of 10 consecutive patients who were diagnosed with massive APF after puncture and underwent TAE at our hospital from 1 April 2012 to 30 September 2019.

RESULTS

Out of 10 cases, eight demonstrated a simple type and the other two cases a complex network type on the digital subtraction angiography pattern of massive APF. In two simple-type cases for which re-embolization was required, other subsegmental branches were embolized. The two cases showing a complex network type had been embolized via not only the subsegmental branch, but also the extrahepatic and multiple subsegmental branches. Child-Pugh scores were improved in eight of the ten cases. PVT was seen in six cases before embolization, but disappeared after embolization in all cases, despite the fact that three cases had not received anticoagulant therapy. Six cases had digestive varices before embolization, suggesting portal hypertension, and two of the six cases with esophageal varices and one with gastric varices decreased after embolization.

CONCLUSION

TAE for massive APF contributed to the improvement of hepatic reserve, the disappearance of PVT, and the improvement of portal hypertension; however, embolization of multiple branches may still be required in some cases.

Feasibility and Safety of Delayed Catheter Removal Technique in Percutaneous Trans-Hepatic Portal Vein Embolization

Background: This retrospective study aimed to evaluate the technical feasibility and safety of the delayed catheter removal technique in trans-hepatic portal vein embolization (PVE) and to explore a suitable technique. Methods: This was a retrospective study. In 278 consecutive patients, the puncture tract of the trans-hepatic PVE was treated using the delayed catheter removal technique after PVE. The existence of peripheral hepatic hematoma formation was assessed using ultrasound (US). Follow-up examinations such as magnetic resonance imaging (MRI), computed tomography (CT), and/or US were performed to evaluate perihepatic hematoma formation, hemoperitoneum, and other major complications. Results: Instant hemostasis was achieved in all patients after the procedure. PVE-associated complications were observed in 9 patients (3.24%). No perihepatic hematoma or hemoperitoneum was found in any of the patients. Conclusion: With the appropriate technique, the delayed catheter removal technique can be reliably utilized as a substitute for hemostasis as it is simple and free. This technique should be further evaluated and compared with other methods. Advances in knowledge: This study is the first to investigate the safety and feasibility of the delayed catheter removal technique for embolizing the puncture tract of the trans-hepatic PVE.

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

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

Management of Bleed from Percutaneous Portal Puncture Site (post-BRTO) by Trans-jugular-Trans-Hepatic Embolization

We report the case of an elderly male, who was a known case of chronic liver parenchymal disease. He presented with a history of melena for 2 weeks and upper-GI endoscopy revealed fundal varices. He was planned for BRTO. Along with BRTO, a percutaneous trans-hepatic puncture of a branch of the right portal vein was also performed for proper embolization of the varices. The trans-hepatic puncture-tract was embolized after the procedure. However, after 24 hours of the procedure, the patient developed hypotension and abdominal distension due to hemorrhage from the portal puncture site. Portal-venography was performed via the trans-jugular-trans-hepatic route to confirm the source of hemorrhage and embolization of the culprit portal venous branch was performed via the same route. The patient was stable after the procedure.

Various interventional procedures via the trans-jugular route have been routinely described in the literature, including trans-jugular liver biopsies, placement of TIPSS shunts and endovascular interventions for haemodialysis. However, the literature on trans-jugular embolization of portal vein is scarce. This case describes the unexpected clinical situation, in the form of bleeding from the portal puncture site, despite embolization of the trans-hepatic tract after BRTO. Finally, a creative solution was thought of and trans-jugular embolization of the portal vein was performed, which succeeded in terminating the ongoing bleeding from the portal vein.

Portal vein embolization with ethylene-vinyl alcohol copolymer for contralateral lobe hypertrophy before liver resection: safety, feasibility and initial experience

Background

To report our preliminary experience with preoperative portal vein embolization (PVE) using liquid ethylene vinyl alcohol (EVOH) copolymer.

Methods

Retrospectively review of patients with primary or secondary liver malignancies scheduled for extensive hepatectomy after the induction of future liver remnant (FLR) hypertrophy by right or left PVE with EVOH as the only embolic agent between 2014 and 2018 at two academic centers. Cross-sectional imaging liver volumetry data obtained before and 3-6 weeks after PVE were used to assess the FLR volume (FLRV) increase, degree of FLR hypertrophy and the FLR kinetic growth rate (KGR).

Results

Twenty-six patients (17 males; mean age, 58.7±11 years; range, 32-79 years) were included. The technical and clinical success rate was 100%. PVE produced adequate FLR hypertrophy in all patients. Embolization occurred in all targeted portal branches and in no non-target vessels. The %FLRV increased by 52.9%±32.5% and the degree of FLR hypertrophy was 16.7%±6.8%. The KGR was 4.4%±2.0% per week. Four patients experience minor complications after PVE which resolved with symptomatic treatment. The resection rate was 84.5%. One patient died during surgery for reasons unrelated to PVE.

Conclusions

Preoperative PVE with EVOH copolymer is feasible, safe, and effective in inducing FLR hypertrophy.

Hybrid transileocecal portal vein embolization associated with staging laparoscopy for planned major hepatectomy in advanced hepatobiliary cancers

BACKGROUND

Portal vein embolization (PVE) is widely used to promote the hypertrophy of a future liver remnant (FLR) and reduce posthepatectomy liver failure. The aim of this study was to evaluate the efficacy of transileocecal portal embolization (TIPE) associated with staging laparoscopy (hybrid lap-TIPE) for a planned hepatectomy in advanced hepatobiliary cancers.

METHODS

The hybrid lap-TIPE procedure consisted of staging laparoscopy for complete screening of the abdominal cavity with cytoreductive surgery and subsequent TIPE. Data on hybrid lap-TIPE, performed between March 2013 and February 2020, were collected retrospectively.

RESULTS

Hybrid lap-TIPE was conducted for 52 patients, and a subsequent TIPE was accomplished in 42 patients (80.8%), since staging laparoscopy detected latent or unresectable factors in 13 patients (25.0%), among which 2 patients with hepatocellular carcinoma and 1 with colorectal liver metastasis received laparoscopic cytoreductive surgery for latent lesions in the FLR. Finally, radical hepatectomy was completed in 36 patients (69.2%), including 3 patients who underwent cytoreductive surgery. The most common operation was an extended right hepatectomy (50.0%), followed by right hepatectomy (30.6%), including 3 hepatopancreatoduodenectomies. The overall morbidity associated with hybrid lap-TIPE and hepatectomy was 7.1% and 41.7%, respectively. The mortality associated with hybrid lap-TIPE and hepatectomy was 0% and 5.6%, respectively. The rates of 2-year survival and 2-year disease-free survival were 64.8% and 61.9%, respectively, after hepatectomy.

CONCLUSIONS

Hybrid lap-TIPE is safe and could be a useful treatment option for patients with advanced hepatobiliary cancer because it can help to identify optimal candidates for PVE followed by a planned hepatectomy.

Feasibility and safety of bisegmentectomy 7-8 while preserving hepatic venous outflow of the right liver - A retrospective cohort study

BACKGROUND

When a hepatic tumor is deeply located in segments 7 and 8 around the right hepatic vein (RHV), right hemihepatectomy (RH) could be excessive owing to the resection of large tumor-free segments. This study aimed to evaluate the feasibility and safety of bisegmentectomy 7-8 (S7-8) and to compare its surgical outcomes with those of RH.

MATERIALS AND METHODS

Consecutive patients who underwent S7-8 and RH were enrolled in this study. In the S7-8 group, 14 patients with an obvious inferior right hepatic vein (IRHV) (median: 6 mm; range: 3.6-8.8 mm) underwent S7-8 without hepatic vein reconstruction. RHV reconstruction was performed in six patients without an IRHV, involving direct anastomosis of the RHV in five patients and reconstruction using a cryo-preserved iliac vein in one patient.

RESULTS

A total of 61 patients were included (20 in S7-8 group; 41 in RH group). No significant differences were observed other than higher a model of end-stage liver disease score in the RH group than in the S7-8 group (7 [6-20] vs. 6 [6-9], P = 0.003). Post-hepatectomy liver failure including severe grades was more frequent in the RH group (43.9% vs. 10%, P = 0.008). In the S7-8 group, two patients with direct RHV reconstruction had RHV anastomosis obstruction, and eventually required insertion of a metallic stent. However, computed tomography performed 4 weeks after the operation showed intact venous outflow of the right liver in the S7-8 group.

CONCLUSION

S7-8 can be performed safely in selected patients with a thick IRHV. For patients with no obvious IRHV, RHV reconstruction could be a good surgical strategy to retain venous outflow of the right liver with feasible outcomes.

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

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

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

Preoperative Portal Vein Embolization in Hepatic Surgery: A Review about the Embolic Materials and Their Effects on Liver Regeneration and Outcome

Liver volume and function after hepatectomies are directly correlated to postoperative complications and mortality. Consequently contemporary liver surgery has focused on reaching an adequate future liver remnant so as to diminish postoperative morbidity and mortality. Portal vein embolization has evolved and is the standard of care as a liver regenerative strategy in many surgery departments worldwide before major liver resections. Different embolic materials have been used for portal vein embolization including gelfoam, ethanol, polyvinyl-alcohol particles, calibrated microspheres, central vascular plugs, coils, n-butyl-cyanoacrylate glue, fibrin glue, polidocanol-foam, alcoholic prolamin solution, and ethylene vinyl alcohol copolymer, as sole occluders or in varied combinations. While to date there has been no prospective controlled trial comparing the efficacy of different embolic materials in portal vein embolization, retrospective data insinuates that the use of n-butyl-cyanoacrylate and absolute ethanol produces higher contralateral liver hypertrophies. In this review, we evaluated publications up to August 2019 to assess the technical and regenerative results of portal vein embolization accomplished with different embolic materials. Special attention was given to specific aspects, advantages, and drawbacks of each embolic agent used for portal vein embolization, its liver regenerative performance, and its influence on patient outcome.

A Case of Portal Venous Stenting for Metastatic Hilar Stricture After the Radical Resection of Colon Cancer

Like standard stenting in an unresectable malignant stricture of the biliary or digestive tract, minimally invasive modality for portal stenosis is indispensable for palliation. We describe here a safe and practical procedure of portal stenting in a case of metastatic hilar strictures developed nine years after the radical resection of sigmoid colon cancer. After urgent delivery of the biliary tract stenting for the relief of jaundice, the patient received palliative stenting for the stricture of the portal trunk. Transhepatic approach, via the anterior branch, of the portal vein intervention may fit into the standard aspects for portal stenting.

Percutaneous Portal Vein Embolization Using a Simplified Sheathless 18-Gauge Trocar Needle Approach: Review of Efficacy and Safety

PURPOSE

Portal vein (PV) embolization (PVE) is traditionally performed via a PV sheath with selective embolization of PV branches. Here, the efficacy and safety of PVE with the use of only an 18-gauge needle is reported.

MATERIALS AND METHODS

Consecutive patients who underwent PVE from 2009 through 2017 were retrospectively reviewed. Forty-five patients (mean age, 60 y ± 7.6; 38 men) underwent 45 PVE procedures. Hepatocellular carcinoma, cholangiocarcinoma, and metastases accounted for 26 (58%), 13 (29%), and 6 (13%) patients, respectively. PVE was performed by puncturing a branch of right PV with an 18-gauge needle under US guidance. Via the same needle, direct portography was performed, followed by PVE with an N-butyl cyanoacrylate/Lipiodol mixture. Percentage increase of future liver remnant (FLR) volume and increase in ratio of FLR to total liver volume were estimated as measures of efficacy. Complications were reported according to Society of Interventional Radiology classification. Fluoroscopy time, procedure time, and dose-area product (DAP) were recorded.

RESULTS

Technical success rate was 100%. The median DAP, fluoroscopy time, and procedure time were 74,387 mGy·cm² (IQR, 90,349 mGy·cm²), 3.5 min (IQR, 2.10 min), and 24 min (IQR, 10.5 min). Among the 23 patients with complete CT volumetry data, mean increase in the ratio of FLR to total liver volume and percentage increase of FLR volume were 12.5% ± 7.7 and 50% ± 33, respectively. There were 3 minor complications (asymptomatic nonocclusive emboli in FLR) and 3 major complications (1 hepatic vein emboli, 1 subphrenic collection, and 1 hepatic infarct).

CONCLUSIONS

PVE via a sheathless 18-gauge needle approach is feasible, with satisfactory FLR hypertrophy.

Evaluation of patients who underwent percutaneous transhepatic portal vein embolisation by Tc-99m GSA scintigraphy

Purpose

To analyse the correlation between the fold change in residual liver volume (RLV) and residual liver uptake at 15 (RLU15) before and after percutaneous transhepatic portal vein embolisation (PTPE).

Material and methods

Between August 2010 and December 2016, 20 patients who underwent PTPE were retrospectively selected. Before and three weeks after PTPE, contrast-enhanced computed tomography (CECT) and Tc-99m GSA scintigraphy were performed to analyse the fold changes in RLV and RLU15, respectively, as well as their correlation.

Results

After PTPE, a significant increase was observed in the RLV (before: 464 ± 99 ml; after: 573 ± 118 ml, p = 0.004) and the RLU15 (before: 11.0 ± 2.9%; after: 17.7 ± 3.8%, p = 5 × 10^-7). The fold increase of RLV and RLU15 in all patients was 1.25 ± 0.15 and 1.66 ± 0.33, respectively. No significant correlation was observed in the fold increase in both RLV and RLU15 (r = 0.14, p = 0.66). In patients no. 3 and 9, who were outliers, the increase in RLV was minimal and RLU15 increased greatly, and these 2 patients underwent radical hepatectomy after PTPE.

Conclusions

No correlation was observed between the fold increase in RLV and RLU15 before and after PTPE. In order to accurately evaluate the residual liver function, it should be considered necessary to evaluate not only by morphological CECT volumetry, but also by functional outcome of Tc-99m GSA scintigraphy.

Residual liver volume may not necessarily reflect RLF. It may be possible to improve the radical resection rate by detecting the potential increase of RLF with RLU15 of Tc-99m GSA scintigraphy.

Hepatic hypertrophy and hemodynamics of portal venous flow after percutaneous transhepatic portal embolization

Background

Percutaneous transhepatic portal embolization (PTPE) is useful for safe major hepatectomy. This study investigated the correlation between hepatic hypertrophy and hemodynamics of portal venous flow by ultrasound sonography after PTPE.

Methods

We analyzed 58 patients with PTPE, excluding those who underwent recanalization (n = 10). Using CT volumetry results 2 weeks after PTPE, the patients were stratified into a considerable hypertrophy group (CH; n = 15) with an increase rate of remnant liver volume (IR-RLV) ≥ 40% and a minimal hypertrophy group (MH; n = 33) with an IR-RLV < 40%. We investigated the hemodynamics of portal venous flow after PTPE and the favorable factors for hepatic hypertrophy.

Results

Univariate and multivariate analysis identified the indocyanine green retention rate at 15 min (ICGR15) and increase rate of portal venous flow volume (IR-pFV) at the non-embolized lobe on day 3 after PTPE as independent favorable factors of IR-RLV. Patients with IR-pFV on day 3 after PTPE ≥100% and ICGR15 ≤ 15% (n = 13) exhibited significantly increased IR-RLV compared with others (n = 35).

Conclusions

Cases with high IR-pFV on day 3 after PTPE exhibited better hepatic hypertrophy. Preserved liver function and increased portal venous flow on day 3 were important.

Intrahepatic portal-venous shunts during PVE

Portal venous embolization (PVE) is a well-validated technique to promote contralateral liver lobe hypertrophy prior to hepatic resection. We present a case of a patient with Type IV cholangiocarcinoma undergoing PVE prior to hepatic surgical resection. However, intrahepatic portal-venous shunts were incidentally found during the procedure and were subsequently embolized using embolic coils and N-butyl cyanoacrylate. While most patients with congenital portal-venous shunts remain asymptomatic, an unrecognized shunt during PVE could have resulted in a devastating complication secondary to nontarget embolization through the fistula. To our knowledge, this is the first reported case of a portal-venous shunt being discovered during a PVE.

Increasing the remnant liver volume using portal vein embolization

Background: Portal vein embolization (PVE) is a common procedure to induce hypertrophy of the remnant liver (RL) before major hepatectomy. Objective: Evaluate increased RL volume after PVE based on CT volumetric measurement. Methods: Multi-detector computed tomography (MDCT) was used to measure hepatic volumetric measurement, including total liver volume and RL volumes of pre- and post-PVE. Complications were recorded from PVE and from three-month after post-extended hepatectomy liver dysfunction. Result and conclusion: There was a 10% increase in RL volume. Mean days between CT and PVE were 20 days. No major complications from PVE were observed.

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.

The role of interventional radiology in the treatment of intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC) is the second most common primary hepatic malignancy after hepatocellular carcinoma. Complete surgical resection remains the only potentially curative option for patients with ICC. However, until now, early diagnosis with potential surgical intervention has been the exception rather than the rule with only 30% of patients qualifying for attempted surgical cure. Many patients are unresectable because of disease stage, anatomic conditions, medical comorbidities, and small future remnant liver. Interventional radiology procedures are available for these types of patients with intra-arterial therapies and/or ablative treatments both for curative and for palliative treatment. The goals of interventional therapy are to control local tumor growth, to relieve symptoms, and to improve and preserve quality of life. The choice of treatment depends largely on tumor extent and patient performance. No randomized studies exist to compare treatments. The present review describes the current evidence of the interventional treatments in the management of the ICC. Moreover, interventional procedures available to increase the future liver reserve before surgery were analyzed.

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.

The role of portal vein embolization in the surgical management of primary hepatobiliary cancers. A systematic review

BACKGROUND

Primary liver and biliary cancers are very aggressive tumors. Surgical treatment is the main option for cure or long term survival. The main purpose of this systematic review is to underline the indications for portal vein embolization (PVE), in patients with inadequate future liver remnant (FLR) and to analyze other parameters such as resection rate, morbidity, mortality, survival after PVE and hepatectomy for primary hepatobiliary tumors. Also the role of trans-arterial chemoembolization (TACE) before PVE, is investigated.

METHODS

A systematic search of the literature was performed in Pub Med and the Cochrane Library from 01.01.1990 to 30.09.2015.

RESULTS

Forty articles were selected, including 2144 patients with a median age of 61 years. The median excision rate was 90% for hepatocellular carcinomas (HCCs) and 86% for hilar cholangiocarcinomas (HCs). The main indications for PVE in patients with HCC and presence of liver fibrosis or cirrhosis was FLR <40% when liver function was good (ICGR15 < 10%) and FLR < 50% when liver function was affected (ICGR15:10-20%). The combination of TACE and PVE increased hypertrophy rate and was associated with better overall survival and disease free survival and should be considered in advanced HCC tumors with inadequate FLR. In patients with HCs PVE was performed, after preoperative biliary drainage, when FLR was <40%, in the majority of studies, with very good post-operative outcome. However indications should be refined.

CONCLUSION

PVE before major hepatectomy allows resection in a patient group with advanced primary hepato-biliary tumors and inadequate FLR, with good long term survival.

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.

Intratumoral pseudoaneurysms in hepatocellular carcinoma: do they occur de novo without any prior intervention? A tertiary care center experience of 6 years

BACKGROUND

Intratumoural pseudoaneurysms (ITPA) within hepatocellular carcinomas (HCC) usually arise as postprocedural complications of endovascular therapies or surgical procedures. Their de novo presence in HCC without any prior interventions has not been adequately described in medical literature.

PURPOSE

To evaluate and quantify the presence of intratumoural pseudoaneurysms (ITPA) within hepatocellular carcinomas (HCC) prior to any intervention.

MATERIAL AND METHODS

Retrospective cross-sectional review of 519 patients with HCC at a tertiary care university hospital with the purpose to evaluate and quantify the presence of ITPA present prior to any therapy. Patients' baseline data along with viral marker status, alpha fetoprotein (AFP) levels, imaging findings, and any prior treatment provided were recorded. Multi-detector computed tomography (MDCT) scans of selected patients were reviewed for presence of any ITPA and their incidence was calculated.

RESULTS

ITPAs without any prior therapy were found in 5% (25/519) of patients with HCC. Seventeen of 25 (68%) patients had liver cirrhosis while eight of 25 (32%) patients were non-cirrhotic on imaging. Multiple ITPAs were seen in 44% (11/25) of patients. Eight percent (2/25) of patients had pseudoaneurysm-associated hemorrhage, 20% (5/25) had lung metastasis, 12% (3/25) had portal vein thrombosis, 8% (2/25) had hepatic vein thrombosis, and 16% (4/25) had peritumoral hematoma. The incidence of de novo ITPAs occurring in patients with HCC without any prior therapy or intervention was 0.24%.

CONCLUSION

These cases provide a unique insight into an additional feature of HCC and usefulness of recognizing the ITPAs on imaging studies. Although de novo ITPAs in HCC are uncommon, occurring with an incidence rate of 0.24%, their presence in hypervascular hepatic lesion may point towards the diagnosis of HCC. Additionally, they should be accounted for in management planning as they can lead to complications of rupture and hemorrhage.

Intrahepatic Cholangiocarcinoma

Cholangiocarcinoma is a rare malignancy that arises from epithelial cells of the biliary system. Its desmoplastic histology and the heterogeneity of its presentation have contributed to its poor prognosis, with limited therapeutic options previously available. However, recent advances using locoregional therapy may expand the treatment arsenal used to manage this resistant malignancy. Although surgical resection has previously been reserved for relatively few patients because of inadequate hepatic reserve, portal vein embolization can induce contralateral hepatic lobe hypertrophy to increase the number of patients eligible for resection. For unresectable cases, both transarterial chemoembolization and yttrium-90 radioembolization have shown effectiveness in controlling tumor growth and prolonging survival.

Portal vein embolization: rationale, technique, and current application

Portal vein embolization (PVE) is a technique used before hepatic resection to increase the size of liver segments that will remain after surgery. This therapy redirects portal blood to segments of the future liver remnant (FLR), resulting in hypertrophy. PVE is indicated when the FLR is either too small to support essential function or marginal in size and associated with a complicated postoperative course. When appropriately applied, PVE has been shown to reduce postoperative morbidity and increase the number of patients eligible for curative intent resection. PVE is also being combined with other therapies in novel ways to improve surgical outcomes. This article reviews the rationale, technical considerations, and current use of preoperative PVE.

Percutaneous portal vein access and transhepatic tract hemostasis

Percutaneous portal vein interventions require minimally invasive access to the portal venous system. Common approaches to the portal vein include transjugular hepatic vein to portal vein access and direct transhepatic portal vein access. A major concern of the transhepatic route is the risk of postprocedural bleeding, which is increased when patients are anticoagulated or receiving pharmaceutical thrombolytic therapy. Thus percutaneous portal vein access and subsequent closure are important technical parts of percutaneous portal vein procedures. At present, various techniques have been used for either portal access or subsequent transhepatic tract closure and hemostasis. Regardless of the method used, meticulous technique is required to achieve the overall safety and effectiveness of portal venous procedures. This article reviews the various techniques of percutaneous transhepatic portal vein access and the various closure and hemostatic methods used to reduce the risk of postprocedural bleeding.

Portal vein embolization: cross-sectional imaging of normal features and complications

OBJECTIVE

The purpose of this article is to describe the role of cross-sectional imaging before portal vein embolization, the normal imaging findings after the procedure, and the imaging findings of postprocedural complications.

CONCLUSION

With the increasing emphasis on aggressive resection of hepatic malignancies, portal vein embolization has evolved into a leading technique. Radiologists need to be familiar with the normal imaging findings after this procedure and with the imaging findings of postprocedural complications.

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

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

Acute Thrombosis of Left Portal Vein during Right Portal Vein Embolization Extended to Segment 4

Portal vein thrombosis (PVT) is an uncommon, but potentially devastating complication of portal vein embolization (PVE). Its occurrence relates to both local and systemic risk factors. In the setting of PVE, precipitating factors include injury to the vessel wall and reduced portal flow. Contributory factors include portal hypertension, hypercoagulopathy, inflammatory processes, malignancy, pregnancy, oral contraceptive use, and asplenia. The goal of therapy is to prevent thrombus progression and lyse existing clot. Hepatectomy is impossible if adequate recanalization has not occurred and/or overt portal hypertension develops. The mechanisms for thrombus development, its diagnosis, management, and prognosis are discussed.

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.