Incomplete Ablation Research Articles

Left atrial appendage clipping during hybrid atrial fibrillation ablation: a very long-term, single-center experience

Abstract Background/introduction Epicardial left atrial appendage (LAA) clipping is an effective strategy for stroke prophylaxis in high thromboembolic (TE) and bleeding risk patients with atrial fibrillation (AF). In addition to LAA exclusion from systemic circulation, clipping promotes concomitant appendage isolation, which might have positive impacts on arrhythmia control. Purpose The aim of this study was to report safety, success rate, and the long-term clinical outcomes of LAA clipping in a large cohort of AF patients undergoing concomitant hybrid ablation. Methods Consecutive patients undergoing hybrid AF ablation between 2013 and 2023 were enrolled. Hybrid ablation was performed in a one-step procedure consisting of thoracoscopic epicardial radiofrequency (RF) ablation followed by endocardial mapping and ablation, if needed. Ablation lesion set included pulmonary vein (PV) and posterior wall (PW) isolation, as well as RF applications to the LAA/posterolateral ridge. LAA clipping was performed via Atriclip exclusion system (Atricure, Inc., The Nederlands) after epicardial ablation. Additional endocardial lesions were performed in case of incomplete epicardial ablation or at physician’s discretion. Results A total of 130 patients were included (mean age: 65±9.4; 72.3% males); among them, 19.2% and 55.4% had persistent or long-standing persistent AF, respectively. Mean CHA2DS2-VASC and HAS-BLED were 3.1±1.1 and 2.3+-0.5. Five patients (3.8 %) had absolute contraindication to long-term oral anticoagulation, 3 (2.3%) had previous life-threatening bleeding events, 17 (13.1%) had a previous TE event. The final clip size was 35mm in 90.7% cases. Acute success was achieved in 97.7%; failure was due to LAA size (n=1), proximity to phrenic nerve (n=1), or bypass graft (n=1). One patient had incomplete occlusion due to a large secondary lobe, which required a second clip. No periprocedural complications related to clipping were documented. At a mean follow-up of 51±35 months, one (0.8%) patient had a stroke and 3 (2.3%) a transient ischemic attack (4 events per 552 patient/years; 0.7%). One patient had a microreentrant tachycardia mapped from the area near the LAA clipping. Conclusion In a large cohort undergoing hybrid AF ablation, epicardial LAA clipping was safe and highly successful. Acute failure was rare and due to LAA morphology or proximity to phrenic nerve and bypass graft. Thromboembolic event rate was very low.

Overexpression of PLK1 Molecule Following Incomplete Thermal Ablation Promotes the Proliferation and Invasion of Residual Hepatocellular Carcinoma.

TAT, a widely used treatment for HCC, can exacerbate the progression of residual HCC. The present study investigated the mechanism of action of PLK1 following ITA of HCC. The PLK1 levels in HCC were determined using qRT-PCR from clinical patient samples, IHC from tissue microarray, and data from globally high-throughput data and microarrays. The PLK1 levels and their effect on the biological phenotype of heat-stress HCC cells were evaluated through in vitro experiments. We detected PLK1 abnormal expression in HCC models of nude mice subjected to ITA. We detected the effects of different PLK1 expression levels on EMT pathway proteins. PLK1 exhibited an overexpression in HCC tissues with an SMD of 1.19 (3414 HCC and 3036 non-HCC tissues were included), distinguishing HCC from non-HCC effectively (AUC = 0.9). The qRT-PCR data from clinical HCC patient samples and IHC from HCC tissue microarray results also indicated an overexpressed level. In the incomplete ablation models, an increased PLK1 expression was found in both heat-stress cells and subcutaneous tumors. The upregulation of PLK1 following ITA was found to enhance the malignancy of HCC and exacerbate the proliferation, migration, and invasion of residual HCC cells, whereas PLK1 knockdown suppressed the biological malignancy of HCC cells. Meanwhile, PLK1 has different regulatory effects on various EMT pathway proteins. PLK1 promotes the progression of residual HCC by activating EMT pathway after ITA, which might provide a novel idea for the treatment and prognosis of residual HCC.

Biofilm ablation on titanium alloy surface by photothermal and chemotherapeutic synergistic therapy

With prolonged exposure in the human body, titanium alloy implants face challenges associated with bacterial attachment and proliferation, leading to implant failure and severe complications. Photothermal therapy (PTT) emerges as an efficient strategy for biofilm elimination. However, the local high temperature of PTT and incomplete bacteria ablation in low-temperature PTT pose risks of damage to normal tissues and biofilm recalcitrance, respectively. In this study, we synergistically combined photothermal therapy and chemotherapy to mildly disrupt biofilms of Staphylococcus aureus (S. aureus) to enhance the efficiency of biofilm ablation. The synergistic nanoplatform comprises near-infrared-light responsive conjugated polymers, heat-sensitive liposomes, and the antibiotic daptomycin for biofilm elimination. The heat generated by conjugated polymers, stimulated with 808 nm light, alters biofilm permeability and releases antibiotics locally to eradicate biofilm. The nanoparticles exhibit biofilm dispersion activity and can effectively inhibit biofilm growth for up to 5 days. Consequently, this nanoplatform based on conjugated polymers offers a reliable method for ablating biofilms on titanium alloy implant and exhibits potential in drug-resistant clinical applications.

Exploring the impact of insufficient thermal ablation on hepatocellular carcinoma: NDST2 overexpression mechanism and its role in facilitating growth and invasion of residual cancer cells

Objective Incomplete thermal ablation (ITA) fosters the malignancy of residual cells in Hepatocellular carcinoma (HCC) with unclear mechanisms now. This study aims to investigate the expression changes of NDST2 following ITA of HCC and its impact on residual cancer cells. Methods An in vitro model of heat stress-induced liver cancer was constructed to measure the expression of NDST2 using Quantitative Real-Time PCR and Western blotting experiments. The sequencing data from nude mice were used for validation. The clinical significance of NDST2 in HCC was evaluated by integrating datasets. Gene ontology and pathway analysis were conducted to explore the potential signaling pathways regulated by NDST2. Additionally, NDST2 was knocked down in heat stress-induced HCC cells, and the effects of NDST2 on these cells were verified using Cell Counting Kit-8 assays, scratch assays, and Transwell assays. Results NDST2 expression levels are elevated in HCC, leading to a decrease in overall survival rates of HCC patients. Upregulation of immune checkpoint levels in high NDST2-expressing HCC may contribute to immune evasion by liver cancer cells. Additionally, the low mutation rate of NDST2 in HCC suggests a relatively stable expression of NDST2 in this disease. Importantly, animal and cell models treated with ITA demonstrate upregulated expression of NDST2. Knockdown of NDST2 in heat stress-induced liver cancer cells results in growth inhibition associated with gene downregulation. Conclusion The upregulation of NDST2 can accelerate the progression of residual HCC after ITA, suggesting a potential role for NDST2 in the therapeutic efficacy and prognosis of residual HCC.

Thermal Ablation for Small Renal Masses: Identifying Anthropometric Factors for Predicting Perioperative and Oncological Outcomes

ObjectivesTo test for specific anthropometric parameters to predict perioperative outcomes after thermal ablation (TA) for renal cell carcinoma (RCC). Materials and methodsRetrospective single center (2008-2022) analysis of 538 T1a-b RCC patients treated with TA. We tested for specific anthropometric parameters, namely skin to tumor distance (STTD), perirenal fat thickness (PFT), median psoas muscle axial area (PMAA) and median paravertebral muscle axial area (PVMAA), to predict TRIFECTA achievement: (1) absence of CLAVIEN-DINDO≥ 3 complications; (2) complete ablation; (3) absence of ≥ 30% decrease in eGFR.Univariable (ULRM) and multivariable logistic regression models (MLRM) were used for testing TRIFECTA achievement. ResultsOverall, 103 patients (19%) did not achieve TRIFECTA. Of all anthropometric factors, only lower PMAA was associated with no TRIFECTA achievement (10 vs. 11 cm2, P = .02).However, ULRMs and MLRMs did not confirmed the aforementioned association. We than tested for the 3 specific TRIFECTA items. In separate ULRM and MLRM predicting incomplete ablation, both continuously coded STTD (Odds Ratio [OR]: 1.02; CI: 1.01-1.03; P = .02) and STTD strata (STTD > 10 cm; OR: 2.1; CI: 1.1-4.1; P = .03) achieved independent predictor status.Conversely, in separate ULRM and MLRM predicting CLAVIEN-DINDO ≥3 complications, both continuously coded PFT (OR: 1.04; CI: 1.01-1.07; P = .01) and PFT strata (PFT ≥ 14 mm; OR: 3.3; CI: 1.6-10.2; P = .003) achieved independent predictor status.Last, none of the anthropometric parameters were associated with eGFR decrease ≥ 30%. ConclusionNone of the tested anthropometric parameters predicted TRIFECTA achievement. However, when the 3 specific TRIFECTA items were tested, STTD and PFT were associated with, respectively, incomplete ablation and CLAVIEN-DINDO ≥ 3 complications.

Transient, Image-Guided Gel-Dissection for Percutaneous Thermal Ablation.

Image-guided tumor ablative therapies are mainstay cancer treatment options but often require intra-procedural protective tissue displacement to reduce the risk of collateral damage to neighboring organs. Standard of care strategies, such as hydrodissection (fluidic injection), are limited by rapid diffusion of fluid and poor retention time, risking injury to adjacent organs, increasing cancer recurrence rates from incomplete tumor ablations, and limiting patient qualification. Herein, a "gel-dissection" technique is developed, leveraging injectable hydrogels for longer-lasting, shapeable, and transient tissue separation to empower clinicans with improved ablation operation windows and greater control. A rheological model is designed to understand and tune gel-dissection parameters. In swine models, gel-dissection achieves 24 times longer-lasting tissue separation dynamics compared to saline, with 40% less injected volume. Gel-dissection achieves anti-dependent dissection between free-floating organs in the peritoneal cavity and clinically significant thermal protection, with the potential to expand minimally invasive therapeutic techniques, especially across locoregional therapies including radiation, cryoablation, endoscopy, and surgery.

Application of high intensity focused ultrasound combined with nanomaterials in anti-tumor therapy

High intensity focused ultrasound (HIFU) has demonstrated its safety, efficacy and noninvasiveness in the ablation of solid tumor. However, its further application is limited by its inherent deficiencies, such as postoperative recurrence caused by incomplete ablation and excessive intensity affecting surrounding healthy tissues. Recent research has indicated that the integration of nanomaterials with HIFU exhibits a promising synergistic effect in tumor ablation. The concurrent utilization of nanomaterials with HIFU can help overcome the limitations of HIFU by improving targeting and ablation efficiency, expanding operation area, increasing operation accuracy, enhancing stability and bio-safety during the process. It also provides a platform for multi-therapy and multi-mode imaging guidance. The present review comprehensively expounds upon the synergistic mechanism between nanomaterials and HIFU, summarizes the research progress of nanomaterials as cavitation nuclei and drug carriers in combination with HIFU for tumor ablation. Furthermore, this review highlights the potential for further exploration in the development of novel nanomaterials that enhance the synergistic effect with HIFU on tumor ablation.

Technique efficacy and complications after ablation as first surgical intervention for hepatocellular carcinoma: A nationwide database study

IntroductionDespite limited evidence, technique efficacy and complications may be important short-term outcomes after ablation for hepatocellular carcinoma (HCC). We aimed to report these outcomes after ablation as the first surgical intervention for HCC. MethodsThis nationwide cohort study was based on data from the Danish Liver and Biliary Duct Cancer Database and medical records. Variables associated with outcomes were investigated using logistic regression. ResultsFrom 2013 to 2023, 433 patients were included of which 79% were male, 73% had one tumor, and 90% had cirrhosis. Complete ablation was achieved after percutaneous, laparoscopic, and open approach in 84%, 100%, and 96% of the procedures, respectively. Most patients did not experience complications (76%). Open ablation compared with percutaneous was associated with higher risk of complications in multivariable adjusted analysis (Clavien-Dindo grade 2–5 (odds ratio 5.34, 95% confidence interval [2.36; 12.08]) and 3B-5 (5.70, [2.03; 16.01]), and lower risk of incomplete ablation (0.19 [0.05; 0.65]). Number of tumors ≥3 was associated with a higher risk of incomplete ablation (3.88, [1.45; 10.41]). Tumor diameter ≥3 cm was associated with increased risk of complications grade 2–5 (2.84, [1.29; 6.26]) and 3B-5 (4.44, [1.62; 12.13]). Performance status ≥2 was associated with risk of complications grade 3B-5 (5.98, [1.58; 22.69]). Tumor diameter was not associated with technique efficacy. ConclusionOpen ablation had a higher rate of complete ablation compared with percutaneous but was associated with a higher risk of complications. Tumor diameter ≥3 cm and performance status ≥2 were associated with a higher risk of complications.

Outcomes after Surgical Microwave Ablation for the Treatment of Colorectal Liver Metastasis.

Colorectal cancer (CRC) is the third most common cause of cancer mortality worldwide. Of these, approximately 25% will have liver metastasis. We performed 394 microwave ablations (MWAs) and analyzed outcomes for survival and ablation failure. We conducted a retrospective review of patients who underwent a surgical MWA at a single-center high-volume institution from October 2006 to September 2022 using a prospectively maintained database. The primary outcome was overall survival. A total of 394 operations were performed on 328 patients with 842 tumors undergoing MWA. Median tumor size was 1.5 cm (range 0.4 to 7.0 cm), with the median number of tumors ablated per operation being 1 (range 1 to 11). A laparoscopic approach was used 77.9% of the time. Concomitant procedures were performed 63% of the time, most commonly hepatectomy (22.3%), cholecystectomy (17.5%), and colectomy (6.6%). Clavien-Dindo grade III or IV complication occurred in 12 patients (3.6%), and all of these patients had undergone concomitant procedures. Mortality within 30 days occurred in 4 patients (1.2%). The rate of incomplete ablation was 1.5% per tumor. Local recurrence occurred at a rate of 6.3% per tumor. Black patients were found to have a higher incidence of incomplete ablation and local recurrence. One-year survival probability was 91% (95% CI 87.9 to 94.3), with a mean overall survival of 57.6 months (95% CI 49.9 to 65.4 months). Surgical MWA offers a low-morbidity approach to treatment of colorectal liver metastasis, with low rate of failure. This large series reviews the outcomes of MWA as definitive treatment for colorectal liver metastasis.

Surface integrity analysis of Si3N4 under cryogenic assisted femtosecond laser ablation

Femtosecond laser is suitable to process Si3N4, but heat effect forming during machining process could degrade the performance of specimen. To reduce heat damage, in this study, the effects of cryogenic assisted laser machining on the surface quality and micro-structures of Si3N4 was investigated. The femtosecond laser was employed to ablate Si3N4 at various low temperatures, accompanied with comprehensive analysis of the surface roughness, material removal rate and SEM topography. To further illustrate the formation mechanism of surface structure, finite element analysis was conducted. Results indicated that while low temperature exerted negligible effects in single-layer ablation, multi-layer laser machining benefits from improved surface quality. Low temperature mitigated thermal effects and reduced the recast layer area, resulting in decreased surface roughness. The lowest surface roughness was obtained during the machining of the specimen at −60 °C of 1.072 μm, representing a 54.6 % reduction compared to ambient air machining. However, further decreasing the temperature below −60 °C led to an increase in surface roughness. This was attributed to the combined effects of Gaussian beam energy distribution and low temperature, resulting in incomplete ablation of the surface region between two scanning pitches, thereby decreasing surface quality. This research provides valuable insights into the cryogenic assisted femtosecond laser machining.

The influence of microwave ablation parameters on the positioning of trocar in different cancerous tissues: a numerical study

ABSTRACT The present study analyzed the microwave ablation of cancerous tumors located in six major cancer-prone organs and estimated the significance of input power and treatment time parameters in the apt positioning of the trocar into the tissue during microwave ablation. The present study has considered a three-dimensional two-compartment tumour-embedded tissue model. FEA based COMSOL Multiphysics software with inbuilt bioheat transfer, electromagnetic waves, heat transfer in solids and fluids, and laminar flow physics has been used to obtain the numerical results. Based on the mortality rates caused by cancer, the present study has considered six major organs affected by cancer, viz. lung, breast, stomach/gastric, liver, liver (with colon metastasis), and kidney for MWA analysis. The input power (100 W) and ablation times (4 minutes) with apt and inapt positioning of the trocar have been considered to compare the ablation volume of various cancerous tissues. The present study addresses one of the major problems clinicians face, i.e. the proper placement of the trocar due to poor imaging techniques and human error, resulting in incomplete tumor ablation and increased surgical procedures. The highest values of the ablation region have been observed for the liver, colon metastatic liver and breast cancerous tissues compared with other organs at the same operating conditions.

Integrating Navigation-Assisted Ablation in the Locoregional Treatment of Hepatocellular Carcinoma

With the increasing prevalence of hepatocellular carcinoma (HCC), ablative therapy is a critical treatment option to achieve a cancer-free state. The anatomic location of the tumor can be a challenge, and select hepatic locations of a tumor require laparoscopic-assisted strategies to safely reach and treat the lesion. To assess the association of real-time ultrasonography-augmented navigation for HCC ablation with patient survival, operative time, and rate of incomplete ablations. This retrospective case-control study was conducted among a prospectively collected database of more than 750 patients with HCC who were treated with ablation therapy with and without the use of navigation at a single quaternary medical center from June 2011 to January 2021. Data were analyzed from October 2022 through June 2023. Real-time ultrasonography-augmented navigation. The primary outcome was rate of incomplete ablations in patients undergoing HCC ablation with vs without navigation. Secondary outcomes included overall survival (OS), progression-free survival (PFS), and operative time. The analytic cohort included 467 patients (mean [SD] age, 62.4 [7.8] years; 355 male [76.0%]; 21 Hispanic [4.5%], 67 non-Hispanic Black [14.5%], and 347 Non-Hispanic White [75.0%] among 463 patients with race and ethnicity data). The most common etiology of liver disease was hepatitis C infection (187 patients with etiology data [40.0%]), and 348 of 458 patients with TMN staging data (76.0%) had TNM stage 1 disease. There were 187 individuals treated with navigation and 280 individuals treated without navigation. Patients who underwent navigation-assisted ablation were more likely to have stage 2 disease based on TNM staging (62 of 183 patients [33.9%] vs 47 of 275 patients [17.1%] with TMN data; P < .002) and had a higher mean (SD) number of lesions (1.3 [0.5] vs 1.2 [0.5] lesions; P = .002) and a longer mean (SD) operation time (113.2 [29.4] vs 109.6 [32.3] minutes; P = .04). Patients who underwent navigation were also more likely to have tumors in segment 8 (59 patients [32.1%] vs 53 of 275 patients with segment data [19.3%] with segment data; P = .005) and less likely to have tumors in segment 4 (20 patients [10.9%] vs 54 patients with segment data [19.6%]; P = .005). Overall mean (SD) time to recurrence after treatment was 10.0 (12.5) months, with similar rates for patients with navigation vs no navigation. There were no differences in incomplete ablation rate (10 patients [9.2%] vs 10 patients [10.5%]; P = .32), OS, or PFS between patients undergoing ablation with and without navigation. In this study, use of navigation was associated with comparable outcomes to undergoing ablation without navigation, although patients with navigation had more locally advanced disease. These findings suggest that use of real-time navigation in laparoscopic-assisted ablation of liver cancer should be considered as a useful tool for treating challenging tumors.

MRI non-rigid registration with tumor contraction correction for ablative margin assessment after microwave ablation of hepatocellular carcinomas.

This study aims to develop and assess a tumor contraction model, enhancing the precision of ablative margin(AM) evaluation after microwave ablation (MWA) treatment for hepatocellular carcinomas (HCCs). &#xD;Approach: We utilize a probabilistic method called the Coherent Point Drift algorithm to align pre-and post-ablation MRI images. Subsequently, a nonlinear regression method quantifies local tumor contraction induced by MWA, utilizing data from 47 HCC with viable ablated tumors in post-ablation MRI. After automatic non-rigid registration, correction for tumor contraction involves contracting the 3D contour of the warped tumor towards its center in all orientations.&#xD;Main Results: We evaluate the performance of our proposed method on 30 HCC patients who underwent MWA. The Dice similarity coefficient between the post-ablation liver and the warped pre-ablation livers is found to be 0.95±0.01, with a mean corresponding distance between the corresponding landmarks measured at 3.25±0.62mm. Additionally, we conduct a comparative analysis of clinical outcomes assessed through MRI over a 3-month follow-up period, noting that the AM, as evaluated by our proposed method, accurately detects residual tumor after MWA.&#xD;Significance: Our proposed method showcases a high level of accuracy in MRI liver registration and AM assessment following ablation treatment. It introduces a potentially approach for predicting incomplete ablations and gauging treatment success.

Percutaneous microwave ablation for early-stage intrahepatic cholangiocarcinoma: A single-institutional cohort.

Cholangiocarcinoma (CCA) is the second-most common primary hepatic malignancy with an increasing incidence over the past two decades. CCA arises from the epithelial cells lining the bile ducts and can be classified as intrahepatic, perihilar, or distal based on the site of origin in the biliary tree. Surgical resection is the definitive curative therapy for early-stage intrahepatic CCA; however, only a minority of patients may be ideal surgical candidates. Percutaneous microwave ablation (MWA) is a minimally invasive procedure widely used for hepatocellular carcinoma and colorectal cancer metastases to the liver. Growing evidence suggests MWA can play a role in the management of patients with early-stage intrahepatic CCA. In this study, we aim to describe the safety and efficacy of MWA for the management of intrahepatic CCA. A retrospective review of patients with intrahepatic CCA treated with MWA at our tertiary referral medical center was performed. Eight patients were treated between 2014 and 2019. Diagnosis of CCA was made based on histopathological studies of samples obtained by surgical resection or percutaneous liver biopsy. All procedures were performed under computed tomography (CT) guidance using a high-power single antenna MWA system. General anesthesia was used for all procedures. Patient medical history, procedural technical information, outcomes, and follow-up data were reviewed. Progression-free survival was estimated with a Kaplan-Meier curve. A total of 25 tumors with an average size of 2.2 ± 1.7 cm (range 0.5-7.8) were treated with MWA. Our cohort consisted of eight patients (4 males and 4 females) with an average age of 69.3 ± 5.7 years (range 61-79). Three out of eight (3/8, 37.5%) patients were treated initially with surgical resection. NASH-related cirrhosis was documented in 3/8 (37.5%) patients, while 1/8 (12.5%) had alcoholic cirrhosis; the remaining 4 patients (4/8, 50%) did not have cirrhosis. All patients were discharged within 24 h after ablation. Average total follow-up time was 10.6 ± 11.8 months (range 0-41). The incomplete ablation rate and local recurrence rate were 4% (1/25 lesions) and 12% (3/25 lesions), respectively. In patients who do not qualify for surgical resection, MWA is a safe alternative therapy for the treatment of intrahepatic CCA.

Investigation of Circular RNA Expression Profiles in Ultrasound-guided Incomplete Radiofrequency Ablation Transplanted Tumor Models of Human Liver Cancer.

Abnormally expressed circular RNAs (circRNAs) are associated with many diseases and have important biological effects on the regulation of gene expression. However, the circRNA expression profile in incomplete radiofrequency ablation (RFA)-treated liver cancer (LC) patients has not been characterized. This study investigated the potential biological effects of differentially expressed (DE) circRNAs in an incomplete RFA-treated transplantation tumor model of human LC. A circRNA microarray was utilized to analyze changes in the circRNA expression profiles. CircRNA host gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were also conducted using computational biology. Quantitative real-time PCR (qPCR) was also performed on the selected DE-circRNAs to verify the reliability of the microarray. The circRNA/miRNA interactions were predicted by Arraystar software and confirmed by a dual-luciferase assay. Following RFA incomplete ablation, 76 DE-circRNAs were detected (|fold change |>1.5, P-value < 0.05), 21 of which were upregulated and 55 of which were downregulated. Computational biological analysis revealed that the T-cell receptor signaling pathway was the most significantly enriched pathway of the genes related to altered expression, as indicated by enrichment of LCK, AKT3 and DLG1. PCR results for the upregulated hsa_circRNA_103595 and downregulated hsa_circRNA_001264 indicated that the circRNA microarray sequencing results were reliable. Double luciferase reporter assays confirmed that hsa-miR-185-3p was the target miRNA of hsa_circRNA_103595. The current study confirmed the changes in the expression profiles of circRNAs in tumor transplantation models after incomplete ablation, these changes may play a crucial role in the pathophysiological process of residual cancer transplantation tumors. These findings could lead to new directions for investigating the molecular biological mechanisms underlying RFA-treated LC as well as new ideas for treating LC by regulating circRNAs.

Clinical application of optical and electromagnetic navigation system in CT-guided radiofrequency ablation of lung metastases

Purpose To evaluate the clinical value of CT-guided radiofrequency ablation (RFA) in the diagnosis and treatment of pulmonary metastases under optical and electromagnetic navigation. Methods Data on CT-guided radiofrequency ablation treatment of 93 metastatic lung lesions in 70 patients were retrospectively analyzed. There were 46 males and 24 females with a median age of 60.0 years (16–85 years). All lesions were ≤3cm in diameter. 57 patients were treated with 17 G radiofrequency ablation needle puncture directly ablated the lesion without biopsy, and 13 patients were treated with 16 G coaxial needle biopsy followed by radiofrequency ablation. There were 25 cases in the optical navigation group, 25 in the electromagnetic navigation group, and 20 in the non-navigation group. The navigation group was performed by primary interventionalists with less than 5 years of experience, and the non-navigation group was performed by interventionalists with more than 5 years of experience. Result All operations were successfully performed. There was no statistically significant difference in the overall distribution of follow-up results among the optical, electromagnetic, and no navigation groups. Complete ablation was achieved in 84 lesions (90.3%). 7 lesions showed incomplete ablation and were completely inactivated after repeat ablation. 2 lesions progressed locally, and one of them still had an increasing trend after repeat ablation. No serious complications occurred after the operation. Conclusions Treatment with optical and electromagnetic navigation systems by less experienced operators has similar outcomes to traditional treatments without navigational systems performed by more experienced operators.

Therapeutic effectiveness of high-intensity focused ultrasound (HIFU) ablation in patients with unresectable hepatocellular carcinoma.

490 Background: High-intensity focused ultrasound (HIFU) ablation is a new therapeutic method for treatment of solid tumor. To determine the efficacy and safety of HIFU, we report our experience for local therapy of primary or metastatic hepatocellular carcinoma (HCC). Methods: From January 2015 to December 2022, forty- eight patients with unresectable HCC underwent single or two therapeutic sessions of HIFU under general anesthesia. Ten patients with liver metastasis from colon cancer and three patients with liver metastasis from stomach cancer were included. We used HIFU, ultrasound-guided extracorporeal system (HIFU Technology Company, Chongqing, China). Thirty-three patients received transarterial embolization before HIFU. Thirteen patients were treated with chemotherapy before HIFU. Technical effectiveness per patient and per masses was assessed according to clinical findings and MR imaging at follow-up. Complications were also recorded. Results: We treated total 78 tumors in 48 patients. The tumor size ranged from 1.3 cm to 12 cm in diameter. Small (&lt; 3 cm), intermediate (3-5 cm) and large tumors (&gt;5 cm) are 44, 24 and 10 patients, respectively. Average procedure time was 4 hours 10 minutes with 68 minutes treatment time. We made the artificial pleural effusion to get treatment field in 25 patients. Mean follow-up period was 52 weeks. For the technical effectiveness per patient as follows: complete ablation with no evidence of recurrence on follow up in 18%, apparent complete ablation of target mass with progression of new lesions on follow up in 29%, recurrence after apparent complete ablation in 26%, and incomplete ablation at 2 week follow up in 27%. Average post-procedure hospital day was 5.4 days. No severe complication except mild right upper quadrant pain was observed after treatment. Conclusions: HIFU is an effective and safe treatment option for local image-guided tumor ablation in patients with unresectable HCC. Although further study is necessary, these results show that HIFU may be helpful in treating unresectable HCC.

Efficacy and safety of percutaneous ultrasound-guided thermal ablation in the treatment of cervical metastatic lymph nodes from papillary thyroid carcinoma.

To evaluate the efficacy and safety of percutaneous ultrasound-guided thermal ablation in the treatment of cervical metastatic lymph nodes (LNs) from papillary thyroid carcinoma (PTC). A total of 77 patients with 79 LNs ablated by microwave ablation (MWA) or radiofrequency ablation (RFA) between September 2018 and October 2022 were enrolled in this study. After treatment, patients were followed up with measurement of diameters of LNs and serum thyroglobulin (s-Tg) at 1, 3, 6, and 12 months and annually thereafter. The paired t-test was used to compare the changes of s-Tg level, diameters of LNs before and after ablation. There were no serious complications related to ablation while one case of incomplete ablation in MWA was found during follow-up. The mean longest and shortest diameter of the ablated LNs reduced from 11.6 ± 4.3 mm to 5.0 ± 4.1 mm (p < 0.001), and from 6.1 ± 1.9 mm to 3.0 ± 2.5 mm (p < 0.001) at the last follow-up visit. Besides, the final volume reduction rate (VRR) was 61.8 ± 56.4% (range, -67.0 -100%). The complete disappearance rate was 46.8%, but there were 4 (5.1%) LNs becoming bigger than before. The average s-Tg level was 9.2 ± 26.6 ng/mL, a data significantly decreased to 3.7 ± 7.0 ng/mL at the last follow-up, but no statistical difference was shown. Thermal ablation is an effective and safe modality for the treatment of metastatic LNs from PTC.

Simultaneous inhibition of heat shock proteins and autophagy enhances radiofrequency ablation of hepatocellular carcinoma.

Radiofrequency ablation (RFA) is a commonly used minimally invasive treatment for hepatocellular carcinoma (HCC). However, incomplete radiofrequency ablation (iRFA) promotes tumor progression and metastasis. There is an urgent need to develop innovative strategies to enhance the efficacy of iRFA. The upregulation of heat shock proteins (HSPs) and activation of protective autophagy in tumor cells upon exposure to sublethal heat enhance the thermotolerance, thereby promoting tumor cell survival. Here, 3-methyladenine (3-MA) and lonidamine (LND) co-encapsulated liposomes (Lip@LND/3-MA) are designed to enhance the efficacy of iRFA by simultaneous inhibition of glycolysis and autophagy. On one hand, LND inhibits hexokinase, a key enzyme in glycolysis, and thus reduces ATP production and consequently suppresses the expression of HSPs. On the other hand, 3-MA, as an autophagy inhibitor, can inhibit protective autophagy after iRFA. Lip@LND/3-MA is confirmed to suppress the expression of HSPs and reduce the autophagy level during RFA. Therefore, the thermotolerance of tumor cells is significantly weakened, leading to remarkably enhanced therapeutic efficacy of iRFA. It is believed that simultaneous inhibition of HSPs and autophagy is a promising therapeutic strategy in clinical practice of RFA.

Placental vessel segmentation and registration in fetoscopy: Literature review and MICCAI FetReg2021 challenge findings

Fetoscopy laser photocoagulation is a widely adopted procedure for treating Twin-to-Twin Transfusion Syndrome (TTTS). The procedure involves photocoagulation pathological anastomoses to restore a physiological blood exchange among twins. The procedure is particularly challenging, from the surgeon’s side, due to the limited field of view, poor manoeuvrability of the fetoscope, poor visibility due to amniotic fluid turbidity, and variability in illumination. These challenges may lead to increased surgery time and incomplete ablation of pathological anastomoses, resulting in persistent TTTS. Computer-assisted intervention (CAI) can provide TTTS surgeons with decision support and context awareness by identifying key structures in the scene and expanding the fetoscopic field of view through video mosaicking. Research in this domain has been hampered by the lack of high-quality data to design, develop and test CAI algorithms. Through the Fetoscopic Placental Vessel Segmentation and Registration (FetReg2021) challenge, which was organized as part of the MICCAI2021 Endoscopic Vision (EndoVis) challenge, we released the first large-scale multi-center TTTS dataset for the development of generalized and robust semantic segmentation and video mosaicking algorithms with a focus on creating drift-free mosaics from long duration fetoscopy videos. For this challenge, we released a dataset of 2060 images, pixel-annotated for vessels, tool, fetus and background classes, from 18 in-vivo TTTS fetoscopy procedures and 18 short video clips of an average length of 411 frames for developing placental scene segmentation and frame registration for mosaicking techniques. Seven teams participated in this challenge and their model performance was assessed on an unseen test dataset of 658 pixel-annotated images from 6 fetoscopic procedures and 6 short clips. For the segmentation task, overall baseline performed was the top performing (aggregated mIoU of 0.6763) and was the best on the vessel class (mIoU of 0.5817) while team RREB was the best on the tool (mIoU of 0.6335) and fetus (mIoU of 0.5178) classes. For the registration task, overall the baseline performed better than team SANO with an overall mean 5-frame SSIM of 0.9348. Qualitatively, it was observed that team SANO performed better in planar scenarios, while baseline was better in non-planner scenarios. The detailed analysis showed that no single team outperformed on all 6 test fetoscopic videos. The challenge provided an opportunity to create generalized solutions for fetoscopic scene understanding and mosaicking. In this paper, we present the findings of the FetReg2021 challenge, alongside reporting a detailed literature review for CAI in TTTS fetoscopy. Through this challenge, its analysis and the release of multi-center fetoscopic data, we provide a benchmark for future research in this field.