Biliary stents for active materials and surface modification: Recent advances and future perspectives

Demand for biliary stents has expanded with the increasing incidence of biliary disease. The implantation of plastic or self-expandable metal stents can be an effective treatment for biliary strictures. However, these stents are nondegradable and prone to restenosis. Surgical removal or replacement of the nondegradable stents is necessary in cases of disease resolution or restenosis. To overcome these shortcomings, improvements were made to the materials and surfaces used for the stents. First, this paper reviews the advantages and limitations of nondegradable stents. Second, emphasis is placed on biodegradable polymer and biodegradable metal stents, along with functional coatings. This also encompasses tissue engineering & 3D-printed stents were highlighted. Finally, the future perspectives of biliary stents, including pro-epithelialization coatings, multifunctional coated stents, biodegradable shape memory stents, and 4D bioprinting, were discussed.

An exploration of radiological signs in post-intervention liver complications

The advent and progression of radiological techniques in the past few decades have revolutionized the diagnostic and therapeutic landscape for liver diseases. These minimally invasive interventions, ranging from biopsies to complex therapeutic procedures like transjugular intrahepatic portosystemic shunt placement and transarterial embolization, offer substantial benefits for the treatment of patients with liver diseases. They provide accurate tissue diagnosis, allow real-time visualization, and render targeted treatment for hepatic lesions with enhanced precision. Despite their advantages, these procedures are not without risks, with the potential for complications that can significantly impact patient outcomes. It is imperative for radiologists to recognize the signs of these complications promptly to mitigate further health deterioration. Ultrasound, CT, and MRI are widely utilized examinations for monitoring the complications. This article presents an overarching review of the most commonly encountered hepatobiliary complications post-radiological interventions, emphasizing their imaging characteristics to improve patient post-procedure management.

COVID-19-related liver injury: Mechanisms, diagnosis, management; its impact on pre-existing conditions, cancer and liver transplant: A comprehensive review

AIMS

This review explores the mechanisms, diagnostic approaches, and management strategies for COVID-19-induced liver injury, with a focus on its impact on patients with pre-existing liver conditions, liver cancer, and those undergoing liver transplantation.

MATERIALS AND METHODS

A comprehensive literature review included studies on clinical manifestations of liver injury due to COVID-19. Key areas examined were direct viral effects, drug-induced liver injury, cytokine storms, and impacts on individuals with chronic liver diseases, liver transplants, and the role of vaccination. Data were collected from clinical trials, observational studies, case reports, and review literature.

KEY FINDINGS

COVID-19 can cause a spectrum of liver injuries, from mild enzyme elevations to severe hepatic dysfunction. Injury mechanisms include direct viral invasion, immune response alterations, drug toxicity, and hypoxia-reperfusion injury. Patients with chronic liver conditions (such as alcohol-related liver disease, nonalcoholic fatty liver disease, cirrhosis, and hepatocellular carcinoma) face increased risks of severe outcomes. The pandemic has worsened pre-existing liver conditions, disrupted cancer treatments, and complicated liver transplantation. Vaccination remains crucial for reducing severe disease, particularly in chronic liver patients and transplant recipients. Telemedicine has been beneficial in managing patients and reducing cross-infection risks.

SIGNIFICANCE

This review discusses the importance of improved diagnostic methods and management strategies for liver injury caused by COVID-19. It emphasizes the need for close monitoring and customized treatment for high-risk groups, advocating for future research to explore long-term effects, novel therapies, and evidence-based approaches to improve liver health during and after the pandemic.

CircGNAO1 suppresses hepatocellular carcinoma progression and metastasis via sponging miR-182-5p and regulating FOXO1 expression

BACKGROUND

Hepatocellular carcinoma (HCC) is an aggressive malignant tumor with poor prognosis. Using high-throughput sequencing, we identified a novel circRNA, circGNAO1, which is downregulated in HCC tissues compared to adjacent tissues. However, the potential functions and mechanisms of circGNAO1 in HCC metastasis remain unclear.

METHODS

qRT-PCR was used to detect the expression of circGNAO1, miR-182-5p, and FOXO1 in HCC cells and tissues. Bioinformatics analysis, RNA pull-down assyas, and dual-luciferase reporter assays were employed to verify the interaction between circGNAO1 and miR-182-5p. Functional experiments were conducted using circGNAO1 overexpression and knockdown cell lines, including Transwell, wound healing, and EdU assays. Liver metastasis models and subcutaneous xenograft mouse models were established to analyze the effect of circGNAO1 on HCC metastasis and growth in vivo.

RESULTS

High-throughput sequencing and qRT-PCR results showed that the expression of circGNAO1 dramatically decreased in HCC tissues. Functionally, in vivo and in vitro experiments verified that overexpression of circGNAO1 inhibited the proliferation, migration, invasion and EMT of HCC cells, while knockdown of circGNAO1 promoted these behaviors. Mechanistically, we have demonstrated that circGNAO1 functions as a sponge for miR-182-5p to regulate FOXO1 expression, thereby activating the TGF-β/Smad3 signaling pathway and EMT process.

CONCLUSIONS

circGNAO1 suppresses the progression and metastasis of HCC through the miR-182-5p/FOXO1 axis, and circGNAO1 may be an efficient therapeutic target in HCC.

Ultrasound-Guided Mechanical High-Intensity Focused Ultrasound (Histotripsy) Through an Acoustically Permeable Polyolefin-Based Cranioplasty Device

Histotripsy is a non-thermal focused ultrasound therapy in development for the non-invasive ablation of cancerous tumors. Intracranial histotripsy has been limited by significant pressure attenuation through the skull, requiring large, complex array transducers to overcome this effect.

OBJECTIVE

Recently, a biocompatible, polyolefin-based cranioplasty device was developed to allow ultrasound (US) transmission into the intracranial space with minimal distortion. In this study, we investigated the in vitro feasibility of applying US-guided histotripsy procedures across the prosthesis.

METHODS

Pressure waveforms and beam profiles were collected for single- and multi-element histotripsy transducers. Then, high-speed optical images of the bubble cloud with and without the prosthesis were collected in water and tissue-mimicking agarose gel phantoms. Finally, red blood cell (RBC) tissue phantom and excised brain tissue experiments were completed to test the ablative efficacy across the prosthesis.

RESULTS

Single element tests revealed increased pressure loss with increasing transducer frequency and increasing transducer-to-prosthesis angle. Array transducer measurements at 1 MHz showed average pressure losses of >50% across the prosthesis. Aberration correction recovered up to 18% of the pressure lost, and high-speed optical imaging in water, agarose gels, and RBC phantoms demonstrated that histotripsy bubble clouds could be generated across the prosthesis at pulse repetition frequencies of 50-500 Hz. Histologic analysis revealed a complete breakdown of brain tissue treated across the prosthesis. Conclusion & Significance: Overall, the results of this study demonstrate that the cranial prosthesis may be used as an acoustic window through which intracranial histotripsy can be applied under US guidance without the need for large transcranial array transducers.

Efficacy of microwave ablation in the treatment of large benign thyroid nodules: a multi-center study

OBJECTIVE

To evaluate the efficacy, safety, and improvement of symptoms by ultrasound-guided microwave ablation (MWA) for patients with large benign thyroid nodules (BTNs).

METHODS

Eighty-seven patients with 87 BTNs (≥ 4 cm) treated with MWA between April 2015 and March 2021 were enrolled in this retrospective multicenter study, with clinical and ultrasound examinations performed at the 1st, 3rd, 6th, and 12th months. A multivariable linear mixed effects model was employed to explore the alterations in volume and volume reduction ratio (VRR), as well as the potential factors associated with VRR.

RESULTS

The mean age of the 87 patients was 45.69 ± 14.21 years (range 18-76 years), and the ratio of men to women was 1:4.8. The mean volumes were much decreased at the 12th month after ablation compared to the initial volumes (p < .001). The mean VRR was 76.09% at the 12th month. The technique efficacy (VRR > 50%) was 90.80% at the 12th month. A multivariate analysis revealed that VRR was related to the initial volume (p = .015), annular flow (p = .010), and nodule composition (p = .024). The mean symptomatic score decreased from 4.40 ± 0.28 to 0.26 ± 0.06 at the 12th month (p < .001). At the same time, the mean cosmetic score decreased from 3.22 ± 0.10 to 1.31 ± 0.08 (p < .001).

CONCLUSION

MWA could serve as a safe and effective therapy for large BTNs, significantly reducing the volume of BTNs and significantly improving compressive symptoms and appearance problems.

CLINICAL RELEVANCE STATEMENT

Microwave ablation could serve as a safe and effective therapy for large benign thyroid nodules, leading to significant volume reduction and satisfied symptom and cosmetic alleviation period.

KEY POINTS

• This multicenter study investigated the feasibility and safety of microwave ablation for large benign thyroid nodules. • After ablation, the nodule volume was significantly reduced, and patients' symptoms and appearance problems were significantly improved. • Microwave ablation is feasible for large benign thyroid nodules and has been a supplement treatment.

Contribution and advances of robotics in percutaneous oncological interventional radiology

The advent of robotic systems in interventional radiology marks a significant evolution in minimally invasive medical procedures, offering enhanced precision, safety, and efficiency. This review comprehensively analyzes the current state and applications of robotic system usage in interventional radiology, which can be particularly helpful for complex procedures and in challenging anatomical regions. Robotic systems can improve the accuracy of interventions like microwave ablation, radiofrequency ablation, and irreversible electroporation. Indeed, studies have shown a notable decrease of an average 30% in the mean deviation of probes, and a 40% lesser need for adjustments during interventions carried out with robotic assistance. Moreover, this review highlights a 35% reduction in radiation dose and a stable-to-30% reduction in operating time associated with robot-assisted procedures compared to manual methods. Additionally, the potential of robotic systems to standardize procedures and minimize complications is discussed, along with the challenges they pose, such as setup duration, organ movement, and a lack of tactile feedback. Despite these advancements, the field still grapples with a dearth of randomized controlled trials, which underscores the need for more robust evidence to validate the efficacy and safety of robotic system usage in interventional radiology.

Laser ablation for spongiform thyroid nodules: identifying baseline nodule volume and energy to be delivered for successful treatment

BACKGROUND

Laser ablation (LA) is a minimally invasive treatment. It has been widely used since the early 2000s to induce volume reduction of symptomatic benign thyroid nodules. Up to 40% of laser-treated nodules have been reported to achieve a volume reduction of <50% (technique inefficacy) at 12 months and tend to regrow over time.

OBJECTIVE

This study aimed to assess the optimal baseline volume and energy to be delivered to minimize technique inefficacy.

METHODS

This was a retrospective study. Data were collected, including baseline volume, energy delivered, and 12-month volume reduction ratio (VRR) of spongiform nodules (EU-TIRADS 2) treated with LA between 2010 and 2020. Based on these data, the optimal baseline volume and energy to be delivered were calculated to maximize the rate of nodules with technique efficacy (VRR ≥ 50% at 12-month follow-up).

RESULTS

A total of 205 patients with spongiform nodules were included in this study. The energy delivered was positively associated with VRR. However, no association was observed between baseline volume and VRR. Delivering energy ≥500 J/mL to nodules with a mean baseline volume of 11.4 ± 4 mL resulted in technique efficacy in 83% of cases.

CONCLUSION

Treating spongiform nodules with a baseline volume of ≤15 mL and delivering energy ≥500 J/mL are key factors for achieving a relevant rate of technique efficacy.

[Local ablative procedures for treatment of thyroid nodules]

Thyroid nodules are very frequent in the iodine deficiency regions of central Europe and some of the affected patients are referred for definitive treatment, such as surgery and radioiodine treatment. In recent years nonsurgical and non-radioiodine techniques have been introduced to treat thyroid gland pathologies. These techniques include the probe-based techniques of radiofrequency, microwave and laser application. The only noninvasive technique is high-intensity focused ultrasound. All mentioned techniques have the goal to reduce the volume of the thyroid nodule by application of energy/heat. The knowledge of all techniques and their advantages and risks is necessary to help physicians and patients in making decisions for the appropriate method of treatment of thyroid nodules.

Cost Effectiveness of Definitive Treatment Strategies for Autonomously Functioning Thyroid Nodules

OBJECTIVE

Autonomously functioning thyroid nodules (AFTN) can be treated with antithyroid drugs, radioactive iodine (RAI), thyroid lobectomy or radiofrequency ablation (RFA). Although surgery is most definitive, some patients require lifelong hormone supplementation. RFA avoids this sequela, but its efficacy depends on nodule size. This study aims to compare the relative cost-effectiveness of RAI, RFA and lobectomy for treatment of AFTNs.

STUDY DESIGN

A Markov analysis model was created to simulate clinical outcomes, costs and utilities for three AFTN treatments: (1) thyroid lobectomy, (2) RAI, and (3) RFA.

PATIENTS

This mathematical model was created using published literature and modeling.

MEASUREMENTS

Transition probabilities, utilities and costs were extracted from published literature, Medicare, and RedBook. The willingness to pay threshold was set to $100,000 per quality-adjusted life year. The model simulated 2-year outcomes, reflecting RFA literature. Sensitivity analyses were conducted to account for uncertainty in model variables.

RESULTS

In the base model, RAI dominated both lobectomy and RFA, with lower estimated cost ($2000 vs. $9452 and $10,087) and higher cumulative utility (1.89 vs. 1.82 and 1.78 quality-adjusted life years). One-way sensitivity analyses demonstrated that relative cost-effectiveness between surgery and RFA was driven by the probability of euthyroidism after RFA and hypothyroidism after lobectomy. RFA becomes more cost-effective than surgery if the rate of euthyroidism after ablation is higher than 69% (baseline 54%).

CONCLUSION

Based on published data, RAI is most cost-effective in treating most AFTN. Surgery is more cost-effective than RFA in most scenarios, but RFA may be more resource-efficient for smaller nodules with a high likelihood of complete treatment.

A Prediction Model for Assessing the Efficacy of Thermal Ablation in Treating Benign Thyroid Nodules ≥ 2 cm: A Multi-Center Retrospective Study

OBJECTIVES

To develop and validate a prediction model utilizing clinical and ultrasound (US) data for preoperative assessment of efficacy following US-guided thermal ablation (TA) in patients with benign thyroid nodules (BTNs) ≥ 2 cm.

MATERIALS AND METHODS

We retrospectively assessed 962 patients with 1011 BTNs who underwent TA at four tertiary centers between May 2018 and July 2022. Ablation efficacy was categorized into therapeutic success (volume reduction rate [VRR] > 50%) and non-therapeutic success (VRR ≤ 50%). We identified independent factors influencing the ablation efficacy of BTNs ≥ 2 cm in the training set using multivariate logistic regression. On this basis, a prediction model was established. The performance of model was further evaluated by discrimination (area under the curve [AUC]) in the validation set.

RESULTS

Of the 1011 nodules included, 952 (94.2%) achieved therapeutic success at the 12-month follow-up after TA. Independent factors influencing VRR > 50% included sex, nodular composition, calcification, volume, and largest diameter (all p < 0.05). The prediction equation was established as follows: p = 1/1 + Exp∑[8.113 -2.720 × (if predominantly solid) -2.790 × (if solid) -1.275 × (if 10 mL < volume ≤ 30mL) -1.743 × (if volume > 30 mL) -1.268 × (if with calcification) -2.859 × (if largest diameter > 3 cm) +1.143 × (if female)]. This model showed great discrimination, with AUC of 0.908 (95% confidence interval [CI]: 0.868-0.947) and 0.850 (95% CI: 0.748-0.952) in the training and validation sets, respectively.

CONCLUSIONS

A clinical prediction model was successfully developed to preoperatively predict the therapeutic success of BTNs larger than 2 cm in size following US-guided TA. This model aids physicians in evaluating treatment efficacy and devising personalized prognostic plans.