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Journal of the American Heart... May 2024Transcatheter renal denervation (RDN) has had inconsistent efficacy and concerns for durability of denervation. We aimed to investigate long-term safety and efficacy of... (Comparative Study)
Comparative Study
BACKGROUND
Transcatheter renal denervation (RDN) has had inconsistent efficacy and concerns for durability of denervation. We aimed to investigate long-term safety and efficacy of transcatheter microwave RDN in vivo in normotensive sheep in comparison to conventional radiofrequency ablation.
METHODS AND RESULTS
Sheep underwent bilateral RDN, receiving 1 to 2 microwave ablations (maximum power of 80-120 W for 240 s-480 s) and 12 to 16 radiofrequency ablations (180 s-240 s) in the main renal artery in a paired fashion, alternating the side of treatment, euthanized at 2 weeks (acute N=15) or 5.5 months (chronic N=15), and compared with undenervated controls (N=4). Microwave RDN produced substantial circumferential perivascular injury compared with radiofrequency at both 2 weeks [area 239.8 (interquartile range [IQR] 152.0-343.4) mm versus 50.1 (IQR, 32.0-74.6) mm, <0.001; depth 16.4 (IQR, 13.9-18.9) mm versus 7.5 (IQR, 6.0-8.9) mm <0.001] and 5.5 months [area 20.0 (IQR, 3.4-31.8) mm versus 5.0 (IQR, 1.4-7.3) mm, =0.025; depth 5.9 (IQR, 1.9-8.8) mm versus 3.1 (IQR, 1.2-4.1) mm, =0.005] using mixed models. Renal denervation resulted in significant long-term reductions in viability of renal sympathetic nerves [58.9% reduction with microwave (=0.01) and 45% reduction with radiofrequency (=0.017)] and median cortical norepinephrine levels [71% reduction with microwave ( <0.001) and 72.9% reduction with radiofrequency ( <0.001)] at 5.5 months compared with undenervated controls.
CONCLUSIONS
Transcatheter microwave RDN produces deep circumferential perivascular ablations without significant arterial injury to provide effective and durable RDN at 5.5 months compared with radiofrequency RDN.
Topics: Animals; Microwaves; Sympathectomy; Renal Artery; Kidney; Sheep; Catheter Ablation; Time Factors; Disease Models, Animal; Blood Pressure; Female; Radiofrequency Ablation
PubMed: 38664237
DOI: 10.1161/JAHA.123.031795 -
Surgical Endoscopy Dec 2023Primary hepatocellular carcinoma (HCC) and colorectal liver metastases (CRLM) represent the liver's two most common malignant neoplasms. Liver-directed therapies such as...
SAGES/AHPBA guidelines for the use of microwave and radiofrequency liver ablation for the surgical treatment of hepatocellular carcinoma or colorectal liver metastases less than 5 cm.
BACKGROUND
Primary hepatocellular carcinoma (HCC) and colorectal liver metastases (CRLM) represent the liver's two most common malignant neoplasms. Liver-directed therapies such as ablation have become part of multidisciplinary therapies despite a paucity of data. Therefore, an expert panel was convened to develop evidence-based recommendations regarding the use of microwave ablation (MWA) and radiofrequency ablation (RFA) for HCC or CRLM less than 5 cm in diameter in patients ineligible for other therapies.
METHODS
A systematic review was conducted for six key questions (KQ) regarding MWA or RFA for solitary liver tumors in patients deemed poor candidates for first-line therapy. Subject experts used the GRADE methodology to formulate evidence-based recommendations and future research recommendations.
RESULTS
The panel addressed six KQs pertaining to MWA vs. RFA outcomes and laparoscopic vs. percutaneous MWA. The available evidence was poor quality and individual studies included both HCC and CRLM. Therefore, the six KQs were condensed into two, recognizing that these were two disparate tumor groups and this grouping was somewhat arbitrary. With this significant limitation, the panel suggested that in appropriately selected patients, either MWA or RFA can be safe and feasible. However, this recommendation must be implemented cautiously when simultaneously considering patients with two disparate tumor biologies. The limited data suggested that laparoscopic MWA of anatomically more difficult tumors has a compensatory higher morbidity profile compared to percutaneous MWA, while achieving similar overall 1-year survival. Thus, either approach can be appropriate depending on patient-specific factors (very low certainty of evidence).
CONCLUSION
Given the weak evidence, these guidelines provide modest guidance regarding liver ablative therapies for HCC and CRLM. Liver ablation is just one component of a multimodal approach and its use is currently limited to a highly selected population. The quality of the existing data is very low and therefore limits the strength of the guidelines.
Topics: Humans; Liver Neoplasms; Carcinoma, Hepatocellular; Microwaves; Catheter Ablation; Treatment Outcome; Radiofrequency Ablation; Colorectal Neoplasms; Retrospective Studies
PubMed: 37957297
DOI: 10.1007/s00464-023-10468-1 -
Cardiovascular and Interventional... Jun 2023
Topics: Humans; Abscess; Microwaves; Liver Neoplasms; Carcinoma, Hepatocellular; Risk Factors; Catheter Ablation; Treatment Outcome
PubMed: 37106124
DOI: 10.1007/s00270-023-03438-6 -
European Radiology May 2023Whether preoperative localisation is necessary and valuable for the microwave ablation (MWA) of small pulmonary lesions with ground-glass opacity (GGO) remains unclear....
OBJECTIVES
Whether preoperative localisation is necessary and valuable for the microwave ablation (MWA) of small pulmonary lesions with ground-glass opacity (GGO) remains unclear. This study aimed to explore the role of the Chiba needle and lipiodol localisation techniques in facilitating MWA and biopsy.
METHODS
This retrospective before-after study included patients with GGOs who underwent conventional MWA and biopsy treatment in our hospital between January 2018 and December 2019 (group A) or who underwent the Chiba needle and lipiodol localisation treatment before MWA and biopsy between January 2020 and December 2020 (group B). The characteristics of each patient and GGO lesion were collected and analysed to evaluate the safety and effectiveness of the localisation technique.
RESULTS
A total of 122 patients with 152 GGOs and 131 patients with 156 GGOs underwent MWA and biopsy in groups A and B, respectively. The primary technique efficacy rate of MWA differed significantly between the two groups (A vs. B: 94.1% vs. 99.4%; p = 0.009). The positive biopsy rate in the two groups was determined by the difference (A vs. B: 93.4% vs. 98.1%; p = 0.042). The incidence of complications did not increase in group B.
CONCLUSIONS
Compared with the unmarked group, the Chiba needle and lipiodol localisation technique improved the positive rate of biopsy and the initial effective rate of MWA, without significantly increasing the complication rate.
KEY POINTS
• The localisation of the Chiba needle and lipiodol could improve the positive biopsy rate and the initial effective rate of MWA. • The localisation of the Chiba needle and lipiodol does not affect the subsequent MWA and biopsy and does not increase the incidence of pneumothorax and haemorrhage.
Topics: Humans; Ethiodized Oil; Lung Neoplasms; Retrospective Studies; Microwaves; Biopsy; Catheter Ablation; Treatment Outcome
PubMed: 36941493
DOI: 10.1007/s00330-023-09486-3 -
International Journal of Hyperthermia :... 2021To study the differences between continuous and short-pulse mode microwave ablation (MWA).
PURPOSE
To study the differences between continuous and short-pulse mode microwave ablation (MWA).
METHODS
We built a computational model for MWA including a 200 mm long and 14 G antenna from Amica-Gen and solved an electromagnetic-thermal coupled problem using COMSOL Multiphysics. We compared the coagulation zone (CZ) sizes created with pulsed and continuous modes under and conditions. The model was used to compare long vs. short pulses, and 1000 W high-powered short pulses. experiments were conducted to validate the model.
RESULTS
The computational models predicted the axial diameter of the CZ with an error of 2-3% and overestimated the transverse diameter by 9-11%. For short pulses, the computer modeling results showed a trend toward larger CZ when duty cycles decreases. In general, short pulsed mode yielded higher CZ diameters and volumes than continuous mode, but the differences were not significant (<5%), as in terms of CZ sphericity. The same trends were observed in the simulations mimicking conditions. Both CZ diameter and sphericity were similar with short and long pulses. Short 1000 W pulses produced smaller sphericity and similar CZ sizes under and conditions.
CONCLUSIONS
The characteristics of the CZ created by continuous and pulsed MWA show no significant differences from experiments and computer simulations. The proposed idea of enlarging coagulation zones and improving their sphericity in pulsed mode was not evident in this study.
Topics: Ablation Techniques; Catheter Ablation; Computer Simulation; Computers; Liver; Microwaves; Radiofrequency Ablation
PubMed: 33719808
DOI: 10.1080/02656736.2021.1894358 -
Journal of Chromatography. A Nov 2019Traditional Chinese medicines (TCMs) have been widely applied to the prevention and treatment of various illnesses for thousands of years. Sample preparation played a... (Review)
Review
Traditional Chinese medicines (TCMs) have been widely applied to the prevention and treatment of various illnesses for thousands of years. Sample preparation played a crucial role in the analysis of TCMs because of the complexity of the sample matrixes. In this paper, recent developments and applications of modern sample preparation techniques for the analysis of TCMs were summarized. The sample preparation techniques to pretreat herbal matrixes included ultrasound-assisted extraction, microwave-assisted extraction, pressurized-liquid extraction, supercritical-fluid extraction, synergistic extraction techniques and so on. The sample preparation techniques mainly applied to pretreating biological matrixes such as microdialysis and microfluidic technique were presented. The sample preparation techniques applied to both herbal and biological matrixes were discussed as well, involving solid phase extraction, matrix solid phase dispersion, solid phase microextraction, cloud point extraction, online coupling sample preparation techniques and so on. In addition, the trends for sample preparation techniques of TCMs were proposed.
Topics: Analytic Sample Preparation Methods; Chromatography, Supercritical Fluid; Medicine, Chinese Traditional; Microwaves; Molecular Imprinting; Solid Phase Microextraction
PubMed: 31358297
DOI: 10.1016/j.chroma.2019.460377 -
International Journal of Hyperthermia :... 2021Microwave ablation is effective for severe secondary hyperparathyroidism, but the difference in efficacy between microwave ablation and parathyroidectomy remains...
BACKGROUND
Microwave ablation is effective for severe secondary hyperparathyroidism, but the difference in efficacy between microwave ablation and parathyroidectomy remains unclear. In this multicenter retrospective cohort study, we compared the long-term clinical efficacy of microwave ablation and parathyroidectomy for severe secondary hyperparathyroidism undergoing hemodialysis.
MATERIALS AND METHODS
The patients were divided into microwave ablation and parathyroidectomy groups. The primary endpoint was the proportion of patients with intact parathyroid hormone (iPTH) concentrations within the target range (100-600 pg/mL) during the efficacy assessment phase. The secondary endpoints were (i) differences in iPTH concentrations over time between the two groups, and (ii) decreases in iPTH concentrations over time in the two groups.
RESULTS
Microwave ablation was performed in 47/92 patients and parathyroidectomy in 45/92. Primary endpoint: iPTH concentrations within the target range were achieved during the efficacy assessment phase in 26/47 patients (55.3%) and in 14/45 (31.1%) patients in the microwave ablation and parathyroidectomy groups, respectively ( = .02). Secondary endpoints: (i) Mean iPTH concentrations during the efficacy assessment phase were significantly higher in the microwave ablation versus parathyroidectomy groups (649 ± 519 pg/mL versus 136 ± 228 pg/mL, respectively; < .01). (ii) Mean decrease in iPTH concentration from baseline was 725 ± 605 pg/mL versus 1369 ± 478 pg/mL in the MWA versus parathyroidectomy groups, respectively ( < .01).
CONCLUSIONS
Ultrasound-guided percutaneous microwave ablation provides higher iPTH target-achieving rates than parathyroidectomy in patients with severe secondary hyperparathyroidism undergoing hemodialysis.
Topics: Humans; Hyperparathyroidism, Secondary; Microwaves; Parathyroid Hormone; Parathyroidectomy; Renal Dialysis; Retrospective Studies
PubMed: 33593216
DOI: 10.1080/02656736.2021.1885754 -
ACS Nano Oct 2023Microwave thermal therapy (MWTT) is one of the most potent ablative treatments known, with advantages like deep penetration, minimal invasion, repeatable operation, and...
Microwave thermal therapy (MWTT) is one of the most potent ablative treatments known, with advantages like deep penetration, minimal invasion, repeatable operation, and low interference from bone and gas. However, microwave (MW) is not selective against tumors, and residual tumors after incomplete ablation will generate immunosuppression, ultimately making tumors prone to recurrence and metastasis. Herein, a nano-immunomodulator (Bi-MOF-l-Cys@PEG@HA, BMCPH) is proposed to reverse the immunosuppression and reactivate the antitumor immune effect through responsively releasing HS in tumor cells for improving MWTT. Under MW irradiation, BMCPH will mediate MWTT to ablate tumors and release l-cysteine (l-Cys) to react with the highly expressed cystathionine β-synthase in tumor to generate HS. The generated HS can inhibit the accumulation of myeloid-derived suppressor cells (MDSCs) and promote the expression of cytotoxic T lymphocytes (CTLs). Moreover, Bi-MOF can also scavenge reactive oxygen species (ROS), a major means of MDSCs-mediated immunosuppression, to further weaken the immunosuppressive effect. Simultaneously, the surface-covered HA will gather CTLs around the tumor to enhance the immune response. This nano gas immunomodulator provides an idea for the sensitive and tunable release of unstable gas molecules at tumor sites. The strategy of HS gas to reverse immunosuppression and reactivate antitumor immune response introduces a direction to reduce the risk of tumor recurrence and metastasis after thermal ablation.
Topics: Humans; Microwaves; Immunosuppression Therapy; Neoplasms; Immunity; Immune Tolerance; Tumor Microenvironment
PubMed: 37781935
DOI: 10.1021/acsnano.3c05936 -
Scientific Reports Jul 2022To investigate the feasibility and effectiveness of 3.0 T wide-bore magnetic resonance (MR)-guided microwave ablation (MA) of liver metastases (LM). From October 2018...
To investigate the feasibility and effectiveness of 3.0 T wide-bore magnetic resonance (MR)-guided microwave ablation (MA) of liver metastases (LM). From October 2018 to May 2020, 39 patients with 63 LM were treated with 3.0 T wide-bore MR-guided 2450-MHz MA therapy. The procedure parameters, technical success, complications, biochemical index changes, local tumor response, local tumor progression (LTP), 12-month disease-free survival (DFS) and 12-month overall survival (OS) were recorded and analyzed. The mean tumor maximum diameter and total procedure time were 3.0 cm and 55.2 min, respectively. Technical success was 100%, but 5 cases (12.8%) had grade-1 complications. Alanine transaminase, aspartate transaminase and total bilirubin showed a slight transient increase on day 3 (P < 0.05) and returned to normal by day 30 (P > 0.05). The complete ablation rates for ≤ 2.5 and > 2.5 cm lesions were 100% and 92.5%, respectively. During the median follow-up of 12.0 months, the LTP rate was 4.8% (3/63), and the 12-month DFS and OS rates were 61.3% and 92.2%, respectively. 3.0 T wide-bore MR-guided MA for LM is a safe and effective approach, especially for small LM.
Topics: Catheter Ablation; Humans; Liver Neoplasms; Magnetic Resonance Spectroscopy; Microwaves; Pilot Projects; Retrospective Studies; Treatment Outcome
PubMed: 35879411
DOI: 10.1038/s41598-022-16989-4 -
International Journal of Hyperthermia :... Oct 2019The role of thermal ablation in the management of T1b renal masses is not well defined. The purpose of this review is to examine current evidence for cryoablation,... (Review)
Review
The role of thermal ablation in the management of T1b renal masses is not well defined. The purpose of this review is to examine current evidence for cryoablation, radiofrequency ablation, and microwave ablation of T1b renal masses as well as review current AUA and EAU guidelines for thermal ablation of T1b masses. Given the size of these tumors, adjunctive maneuvers are often necessary to ensure patient safety and protect vital adjacent structures.
Topics: Ablation Techniques; Carcinoma, Renal Cell; Humans; Kidney Neoplasms; Microwaves
PubMed: 31537163
DOI: 10.1080/02656736.2019.1605097