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

Conversion therapy combined with ALPPS for the treatment of intrahepatic cholangiocarcinoma: a case report

Rationale

Intrahepatic cholangiocarcinoma (ICC) is a highly malignant liver tumor with limited treatment options for advanced cases. Conversion therapy combining immunotherapy, targeted therapy, and chemotherapy offers a promising approach to enable surgical resection, which remains the only curative option.

Patient concerns

A 67-year-old male presented with right upper abdominal pain for two months. Imaging and biopsy confirmed advanced ICC (Stage IV), with a 98 mm tumor, lymphadenopathy, and elevated tumor markers (CA199: 1190.4 U/ml). The disease was deemed unresectable.

Diagnosis

The patient was diagnosed with advanced ICC involving a large hepatic mass, lymph node metastasis, and insufficient liver reserve for conventional resection.

Interventions

The patient received six months of oxaliplatin plus gemcitabine (GEMOX), lenvatinib, and toripalimab, achieving significant tumor regression. A two-step ALPPS procedure was then performed, comprising portal vein ligation and right hepatectomy.

Outcomes

The treatment reduced tumor size (98 mm to 60 mm), normalized tumor markers, and improved liver reserve. Postoperative pathology confirmed >80% tumor remission with negative margins. At 12 months post-surgery, the patient remained disease-free.

Lessons

This case demonstrates that advanced ICC can be downstaged with systemic therapy, enabling resection via ALPPS. The combination of GEMOX, lenvatinib, and toripalimab is an effective and safe conversion therapy regimen. This approach may serve as a model for managing similar advanced cases.

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.

Catheter-Directed Ionic Liquid Embolic Agent for Rapid Portal Vein Embolization, Segmentectomy, and Bile Duct Ablation

Embolic materials currently in use for portal vein embolization (PVE) do not treat the tumor, which poses a risk for tumor progression during the interval between PVE and surgical resection. Here, is developed an ionic-liquid-based embolic material (LEAD) for portal vein embolization, liver ablation, and drug delivery. LEAD is optimized and characterized for diffusivity, X-ray visibility, and cytotoxicity. In the porcine renal embolization model, LEAD delivered from the main renal artery reached vasculature down to 10 microns with uniform tissue ablation and delivery of small and large therapeutics. In non-survival and survival porcine experiments, successful PVE is achieved in minutes, leading to the expected chemical segmentectomy, and delivery of a large protein drug (i.e., Nivolumab) with LEAD. In cholangiocarcinoma mouse tumor models and in ex vivo human tumors, LEAD consistently achieved an effective ablation and wide drug distribution. Furthermore, various strains of drug-resistant patient-derived bacteria showed significant susceptibility to LEAD, suggesting that LEAD may also prevent infectious complications resulting from tissue ablation. With its capabilities to embolize, ablate, and deliver therapeutics, ease of use, and a high safety profile demonstrated in animal studies, LEAD offers a potential alternative to tumor ablation with or without PVE for FLR growth.

Thoracic Complications of Liver-Directed Therapy and Interventions

ABSTRACT

Liver-directed percutaneous and endovascular therapies are effective methods to diagnose and treat various hepatic disorders and malignancies. Because of the close anatomic proximity of the liver to the right hemidiaphragm, pleura, and lung bases, complications can arise involving these structures. Although they are rare, awareness of intrathoracic complications associated with liver-directed therapies and their imaging features will ensure timely detection and management. We aim to review the clinical and imaging features of thoracic complications related to liver-directed therapy and interventions.

A Sticky Situation: Glue Migration during Hepatic Vein Embolization

The addition of hepatic venous embolization to portal venous embolization to achieve ipsilateral liver venous deprivation before major hepatectomy has been suggested to increase the extent of hypertrophy of the future liver remnant. The presented case discusses a hepatic vein embolization procedure complicated by the unintended migration of a glue cast used to achieve hepatic venous occlusion and subsequent management with endovascular retrieval of the glue cast from the inferior vena cava. The emerging role of hepatic venous embolization and associated complications are also discussed.

Non-target lung embolization during portal vein embolization due to an unrecognized portosystemic venous fistula: A case report

BACKGROUND

Portal vein embolization (PVE) is an effective and relatively safe procedure performed prior to major hepatic resection to enhance future liver remnant. Non-target embolization during PVE is rare, and if it occurs, it usually affects the future liver remnant. Intrahepatic portosystemic venous fistulas are extremely rare in non-cirrhotic livers. We report a case of non-targeted lung embolization during PVE due to an unrecognized intrahepatic portosystemic fistula.

CASE SUMMARY

A 60-year-old male presented with metastatic colon cancer of the liver. The patient underwent preoperative right PVE. During the embolization procedure, a small amount of glue and lipiodol emulsion was embolized to the heart and lungs through an unrecognized intrahepatic portosystemic fistula. The patient remained clinically stable and underwent the planned hepatic resection after 4 wk, with an uneventful postoperative course.

CONCLUSION

Conventional portograms and careful evaluation prior to PVE are advisable to avoid such complications.

Radiosurgical interventions in the prevention of post-resection liver failure

Aim. To evaluate the effectiveness of percutaneous ALPPS as a method for preventing post-resection liver failure.

Materials and methods. The methodology involved a retrospective study of the results of portovenous embolization and percutaneous radiofrequency assisted liver partition with portal vein embolization (PRALLPS), in case of the future liver volume <40% . The degree of hypertrophy of the future liver remnant and its rate were assessed in two groups. Complications of manipulation and frequency of postresection hepatic failure were studied.

Results. In the first stage, portenous embolization was successfully performed in 38 patients and PRALLPS was successfully performed in 47 patients. In the second stage, liver resection was performed in 27 (71.1%) and 33 (70%) patients. The most frequent complication of PRALLPS was bile accumulation in the radiofrequency ablation area (13.1%). The incidence of other complications of the first stage did not differ between groups. No differences in blood loss or incidence of liver failure were reported after the second stage. No fatal outcomes reported. The mean degree of hypertrophy and growth did not differ between the groups. The mean time of hypertrophy of the future liver remnant after percutaneous radiofrequency assisted partition of the parenchyma with portal vein embolization and portenous embolization was 13 ± 5 and 18 ± 7 days (p = 0.008).

Conclusion. The results of percutaneous radiofrequency assisted liver partition with portal vein embolization are comparable in terms of safety with those of portenous embolization. Radiofrequency partition of the parenchyma with portal vein embolization enables optimal hypertrophy of the future liver remnant to be achieved faster.

Rheological Properties of Non-Adhesive Embolizing Compounds-The Key to Fine-Tuning Embolization Process-Modeling in Endovascular Surgery

The study of polymers' rheological properties is of paramount importance both for the problems of their industrial production as well as for their practical application. Two polymers used for embolization of arteriovenous malformations (AVMs) are studied in this work: Onyx-18^® and Squid-12^®. Viscosity curve tests and computational fluid dynamics (CFD) were used to uncover viscosity law as a function of shear rate as well as behavior of the polymers in catheter or pathological tissue models. The property of thermal activation of viscosity was demonstrated, namely, the law of dependence of viscosity on temperature in the range from 20 °C to 37 °C was established. A zone of viscosity nonmonotonicity was identified, and a physical interpretation of the dependence of the embolic polymers' viscosity on the shear rate was given on the basis of Cisco's model. The obtained empirical constants will be useful for researchers based on the CFD of AVMs. A description of the process of temperature activation of the embolic polymers' viscosity is important for understanding the mechanics of the embolization process by practicing surgeons as well as for producing new prospective embolic agents.

Aspiration thrombectomy for inferior vena cava tumor thrombus arising from hepatocellular carcinoma

Pharmacomechanical therapy and catheter-directed thrombolysis have been shown to be very effective in the treatment of venous thromboembolism; however, there is much less data regarding inferior vena cava thrombi. Tumor thrombi pose an even greater clinical challenge as anti-coagulation and thrombolysis are not effective. We present the case of a 61-year-old male who presented with an inferior vena cava thrombus emanating from an accessory right hepatic vein, treated with aspiration thrombectomy.

Imaging-guided interventions modulating portal venous flow: evidence and controversies

Portal hypertension is defined by an increase in the portosystemic venous gradient. In most cases, increased resistance to portal blood flow is the initial cause of elevated portal pressure. More than 90% of cases of portal hypertension are estimated to be due to advanced chronic liver disease or cirrhosis. Transjugular intrahepatic portosystemic shunts, a non-pharmacological treatment for portal hypertension, involve the placement of a stent between the portal vein and the hepatic vein or inferior vena cava which helps bypass hepatic resistance. Portal hypertension may also be a result of extrahepatic portal vein thrombosis or compression. In these cases, percutaneous portal vein recanalisation restores portal trunk patency, thus preventing portal hypertension-related complications. Any portal blood flow impairment leads to progressive parenchymal atrophy and triggers hepatic regeneration in preserved areas. This provides the rationale for using portal vein embolisation to modulate hepatic volume in preparation for extended hepatic resection. The aim of this paper is to provide a comprehensive evidence-based review of the rationale for, and outcomes associated with, the main imaging-guided interventions targeting the portal vein, as well as to discuss the main controversies around such approaches.

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.

Imaging of Colorectal Liver Metastasis

Colorectal cancer (CRC) is one of the most common cancers in the world. The most important determinant of survival and prognosis is the stage and presence of metastasis. The liver is the most common location for CRC metastasis. The only curative treatment for CRC liver metastasis (CRLM) is resection; however, many patients are ineligible for surgical resection of CRLM. Locoregional treatments such as ablation and intra-arterial therapy are also available for patients with CRLM. Assessment of response after chemotherapy is challenging due to anatomical and functional changes. Antiangiogenic agents such as bevacizumab that are used in the treatment of CRLM may show atypical patterns of response on imaging. It is vital to distinguish patterns of response in addition to toxicities to various treatments. Imaging plays a critical role in evaluating the characteristics of CRLM and the approach to treatment. CT is the modality of choice in the diagnosis and management of CRLM. MRI is best used for indeterminate lesions and to assess response to intra-arterial therapy. PET-CT is often utilized to detect extrahepatic metastasis. State-of-the-art imaging is critical to characterize patterns of response to various treatments. We herein review the imaging characteristics of CRLM with an emphasis on imaging changes following the most common CRLM treatments.

Novel Approach via the Round Ligament in Portal Vein Embolization

BACKGROUND

The objective of this study was to describe the detailed technique and clinical outcomes of portal vein embolization via the round ligament (RL-PVE) prior to major hepatectomy.

METHODS

Between January 2010 and March 2020, a total of 50 portal vein embolization (PVE) procedures were performed in 50 patients. Of them, seven patients who underwent RL-PVE were enrolled in this study. Percutaneous transhepatic portal vein embolization (PTPE) was not indicated due to the following reasons: bile duct dilation (n = 4), difficulty in visualizing the portal vein on ultrasonography because of severe fatty liver (n = 1), large tumor size (n = 1), and combined surgery with staging laparoscopy (n = 1). The following were reasons for avoiding trans-ileocecal PVE: past laparotomy (n = 5), difficulty in accessing the portal vein due to a large tumor (n = 1), and purpose of preventing small intestinal adhesions before hepatopancreatoduodenectomy (n = 1). The percentage of functional hepatic remnant rates was calculated before and after RL-PVE.

RESULTS

Technical success was achieved in all cases. Five patients underwent embolization of the right portal vein, while two underwent embolization of the left portal vein. The median operative time and blood loss during RL-PVE were 181 min and 33 g, respectively. Morbidity and mortality related to RL-PVE were not observed. The median functional hepatic remnant rate before and after PVE was 55.6% and 63.2%, respectively. Liver functions including Child-Pugh classification were equivalent before and after RL-PVE.

CONCLUSIONS

The RL-PVE technique may be useful in elective cases for which it is difficult to safely perform PTPE or trans-ileocecal approaches.

Future Liver Remnant Hypertrophy after Portal Vein Embolization Is Inversely Correlated with Intrahepatic Tumor Burden

PURPOSE

To determine if there is a correlation between intrahepatic tumor volume and future liver remnant (FLR) hypertrophy after portal vein embolization (PVE).

MATERIALS AND METHODS

Forty-four consecutive patients with hepatocellular carcinoma or metastatic colorectal cancer who underwent PVE from 2009 to 2017 and who had complete imaging follow-up were retrospectively reviewed. To maximize the accuracy of tumor volume measurements, 11 patients were excluded for having more than 5 intrahepatic tumors. Volumetric analyses of the patient livers before and after PVE, as well as pre-embolization intrahepatic tumor burden, were performed.

RESULTS

A significant inverse correlation was observed between tumor volume and FLR hypertrophy after PVE (Spearman ρ = -0.53, P = .002). Initial FLR volume was also inversely correlated with subsequent hypertrophy (P = .01). Fourteen patients received neoadjuvant chemotherapy 1 month prior to intervention. The number of chemotherapy cycles did not affect hypertrophy (P = .57). Patients with cirrhosis experienced less FLR hypertrophy than patients without cirrhosis (P = .02).

CONCLUSIONS

Patients with large intrahepatic tumor burden may experience limited FLR hypertrophy.

The role of bile leak testing in liver resection: a systematic review and meta-analysis

BACKGROUND

Bile leak following liver resection can be associated with significant morbidity. This systematic review and meta-analysis aims to evaluate the effect of intraoperative bile leak testing on postoperative bile leak rate and other complications after liver resection without biliary reconstruction for any cause.

METHODS

PubMed, MEDLINE, Embase, Cochrane Library and grey literature databases were searched for articles between 1960 and 2017 comparing bile leak rates with or without bile leak testing. Standard meta-analysis methods were used. The primary outcome was bile leak rate, and secondary outcomes were overall morbidity, reintervention rate and length of stay.

RESULTS

8 articles met inclusion criteria. Intraoperative bile leak testing after resection was associated with lower postoperative bile leak rate (4.1% vs 12.3%, OR 0.36, 95% CI 0.23-0.55, p < 0.001), overall morbidity (OR 0.67, 95% CI 0.47-0.96, p = 0.030), need for reintervention (OR 0.11, 95% CI 0.03-0.36, p < 0.001) and a shorter duration of hospital stay (2.21 days, 95% CI 0.69-3.73, p = 0.004).

CONCLUSION

The routine use of intraoperative bile leak testing during liver resection results in a significant reduction in postoperative bile leak rate, overall morbidity, length of hospital stay and need for re-intervention. Bile leak testing should be performed after liver resection without biliary reconstruction.

Successful Embolization of Bleeding Ileal Varices with N-butyl Cyanoacrylate via a Recanalized Paraumbilical Vein

A 48-year-old woman with alcoholic liver cirrhosis was admitted to our hospital because of hematochezia and severe anemia. She had been hospitalized many times over the past year for hematochezia of unknown etiology. Contrast-enhanced CT demonstrated ileal varices, which were fed by several ileal veins. These feeding veins were selectively embolized with N-butyl cyanoacrylate (NBCA) via a recanalized paraumbilical vein. The paraumbilical vein instead of the portal vein was punctured to decrease the risk of bleeding complications because she had coagulopathy and ascites. We consider antegrade embolization of ileal varices with NBCA to be a feasible and effective treatment. Access via a paraumbilical vein is an alternative to the transhepatic approach.Level of Evidence Level V, case report.

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.