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1.
Int Braz J Urol ; 50(3): 277-286, 2024.
Article in English | MEDLINE | ID: mdl-38598830

ABSTRACT

PURPOSE: CT-guided MWA is a safe and effective tool that should be utilized in the treatment of small renal masses (SRMs). We aim to clarify the utility of CT-guided MWA by examining patient outcomes such as recurrence, treatment success, changes in renal function, and complications. METHODS: A retrospective review of consecutive patients with SRMs who underwent same day renal mass biopsy (RMB) and CT-guided MWA between 2015 and 2022 was performed. Treatment safety was assessed by 30-day complications according to the Clavien-Dindo system and change in eGFR >30 days post-procedure. Treatment efficacy was defined by local recurrence and incomplete treatment rates and calculated using the Kaplan-Meier method. RESULTS: A total of 108 renal masses were found in 104 patients. The overall complication rate was 7.4% (8/108), of which 4 were major complications (3.7%). For those with renal function available >30 days post ablation, the median eGFR was 47.2 (IQR: 36.0, 57), compared to 52.3 (IQR: 43.7, 61.5) pre-ablation, p<0.0001. 5-year local recurrence free survival was 86%. Among those with biopsy proven malignancy (n= 66), there were five local recurrences (7.54%) occurring at a median of 25.1 months (IQR 19.9, 36.2) and one case (1.5%) of incomplete treatment. CONCLUSIONS: As the medical field continues to evolve towards less invasive interventions, MWA offers a valuable tool in the management of renal masses. With low major complication and recurrence rates, our findings support the utility of CT-guided MWA as a tool for treatment of SRMs.


Subject(s)
Ablation Techniques , Carcinoma, Renal Cell , Catheter Ablation , Kidney Neoplasms , Humans , Kidney Neoplasms/pathology , Carcinoma, Renal Cell/pathology , Microwaves/therapeutic use , Treatment Outcome , Ablation Techniques/adverse effects , Ablation Techniques/methods , Retrospective Studies , Catheter Ablation/methods
2.
Radiol Imaging Cancer ; 6(3): e230159, 2024 May.
Article in English | MEDLINE | ID: mdl-38639585

ABSTRACT

Tissue ablation techniques have long been used in clinical settings to treat various oncologic diseases. However, many of these techniques are invasive and can cause substantial adverse effects. Histotripsy is a noninvasive, nonionizing, nonthermal tissue ablation technique that has the potential to replace surgical interventions in various clinical settings. Histotripsy works by delivering high-intensity focused ultrasound waves to target tissue. These waves create cavitation bubbles within tissues that rapidly expand and collapse, thereby mechanically fractionating the tissue into acellular debris that is subsequently absorbed by the body's immune system. Preclinical and clinical studies have demonstrated the efficacy of histotripsy in treating a range of diseases, including liver, pancreatic, renal, and prostate tumors. Safety outcomes of histotripsy have been generally favorable, with minimal adverse effects reported. However, further studies are needed to optimize the technique and understand its long-term effects. This review aims to discuss the importance of histotripsy as a noninvasive tissue ablation technique, the preclinical and clinical literature on histotripsy and its safety, and the potential applications of histotripsy in clinical practice. Keywords: Tumor Microenvironment, Ultrasound-High-Intensity Focused (HIFU), Ablation Techniques, Abdomen/GI, Genital/Reproductive, Nonthermal Tissue Ablation, Histotripsy, Clinical Trials, Preclinical Applications, Focused Ultrasound © RSNA, 2024.


Subject(s)
Ablation Techniques , Prostatic Neoplasms , Male , Humans , Ablation Techniques/methods , Liver/surgery , Ultrasonography , Kidney , Tumor Microenvironment
3.
PLoS One ; 19(4): e0300309, 2024.
Article in English | MEDLINE | ID: mdl-38578781

ABSTRACT

Radiofrequency ablation (RFA) using the CARTO 3D mapping system is a common approach for pulmonary vein isolation to treat atrial fibrillation (AF). Linkage between CARTO procedural data and patients' electronical health records (EHR) provides an opportunity to identify the ablation-related parameters that would predict AF recurrence. The objective of this study is to assess the incremental accuracy of RFA procedural data to predict post-ablation AF recurrence using machine learning model. Procedural data generated during RFA procedure were downloaded from CARTONET and linked to deidentified Mercy Health EHR data. Data were divided into train (70%) and test (30%) data for model development and validation. Automate machine learning (AutoML) was used to predict 1 year AF recurrence, defined as a composite of repeat ablation, electrical cardioversion, and AF hospitalization. At first, AutoML model only included Patients' demographic and clinical characteristics. Second, an AutoML model with procedural variables and demographical/clinical variables was developed. Area under receiver operating characteristic curve (AUROC) and net reclassification improvement (NRI) were used to compare model performances using test data. Among 306 patients, 67 (21.9%) patients experienced 1-year AF recurrence. AUROC increased from 0.66 to 0.78 after adding procedural data in the AutoML model based on test data. For patients with AF recurrence, NRI was 32% for model with procedural data. Nine of 10 important predictive features were CARTO procedural data. From CARTO procedural data, patients with lower contact force in right inferior site, long ablation duration, and low number of left inferior and right roof lesions had a higher risk of AF recurrence. Patients with persistent AF were more likely to have AF recurrence. The machine learning model with procedural data better predicted 1-year AF recurrence than the model without procedural data. The model could be used for identification of patients with high risk of AF recurrence post ablation.


Subject(s)
Ablation Techniques , Atrial Fibrillation , Catheter Ablation , Pulmonary Veins , Radiofrequency Ablation , Humans , Atrial Fibrillation/diagnosis , Atrial Fibrillation/surgery , Treatment Outcome , Time Factors , Catheter Ablation/methods , Recurrence , Pulmonary Veins/surgery
5.
Neurosurg Rev ; 47(1): 124, 2024 Mar 21.
Article in English | MEDLINE | ID: mdl-38509320

ABSTRACT

Histotripsy, a non-thermal ultrasound technique, holds significant promise in various applications within the realm of brain interventions. While its use for treating brain tumors is somewhat limited, focused ultrasound technology has been extensively investigated for a wide range of purposes within the brain, including disrupting the blood-brain barrier, supporting immunotherapy, addressing conditions like essential tremor, Parkinson's disease, Alzheimer's disease, epilepsy, and neuropathic pain. Research findings indicate that histotripsy can reduce tumor cells with fewer pulses, minimizing the risk of bleeding and cellular injury. The use of MRI sequences such as T2 and T2* enhances the evaluation of the effects of histotripsy treatment, facilitating non-invasive assessment of treated areas. Furthermore, histotripsy displays promise in creating precise brain lesions with minimal edema and inflammation, particularly in porcine models, suggesting considerable progress in the treatment of brain lesions. Moreover, studies confirm its feasibility, safety, and effectiveness in treating intracerebral hemorrhage by safely liquefying clots without causing significant harm to surrounding brain tissue., opening exciting possibilities for clinical applications. The development of transcranial MR-guided focused ultrasound systems based on histotripsy represents a significant breakthrough in overcoming the limitations associated with thermal ablation techniques. Histotripsy's ability to efficiently liquefy clots, minimize skull heating, and target shallow lesions near the skull establishes it as a promising alternative for various brain treatments. In conclusion, histotripsy offers diverse potential in the field of brain interventions, encompassing applications ranging from tumor treatment to the management of intracerebral hemorrhage. While challenges such as accurate monitoring and differentiation of treatment effects persist, ongoing research efforts and technological advancements continue to expand the role of histotripsy in both neurology and neurosurgery.


Subject(s)
Ablation Techniques , Brain Neoplasms , Humans , Animals , Swine , Ultrasonography/methods , Brain Neoplasms/surgery , Cerebral Hemorrhage , Brain/diagnostic imaging , Brain/surgery
6.
Brasília; CONITEC; fev. 2024.
Non-conventional in Portuguese | BRISA/RedTESA, Inca | ID: biblio-1551261

ABSTRACT

INTRODUÇÃO: As técnicas de ablação são usadas para destruir tumores pequenos (até 4 cm), sem removê-los com cirurgia ou para diminuir seu tamanho possibilitando a cirurgia. A ablação por radiofrequência já é utilizada no SUS para tratamento do carcinoma hepático primário localizado, em estágios I e II. PERGUNTA DE PESQUISA: Para adultos com diagnóstico de câncer de cólon e reto com metástase hepática irressecável ou ressecável com alto risco cirúrgico, o tratamento com ablação térmica (por radiofrequência ou por micro-ondas) é eficaz, efetivo, seguro, custoefetivo e viável economicamente quando comparado ao tratamento com quimioterapia? EVIDÊNCIAS CIENTÍFICAS: Identificaram-se, por busca estruturada, duas revisões sistemáticas e dois estudos primários (duas publicações de um ECR de fase 2, de 2002 a 2007, e um estudo observacional retrospectivo). Não foi identificada evidência para ablação por micro-ondas que atendesse aos critérios de elegibilidade deste PTC. No estudo observa


Subject(s)
Humans , Rectal Neoplasms/drug therapy , Digestive System Surgical Procedures/methods , Colonic Neoplasms/drug therapy , Risk Assessment/methods , Ablation Techniques/methods , Liver Neoplasms/secondary , Unified Health System , Brazil , Efficacy , Cost-Benefit Analysis/economics
7.
Radiología (Madr., Ed. impr.) ; 66(1): 47-56, Ene-Feb, 2024. ilus
Article in Spanish | IBECS | ID: ibc-229645

ABSTRACT

La electroporación irreversible o IRE (irreversible electroporation) es una técnica de ablación tumoral no térmica basada en la aplicación de pulsos eléctricos de alto voltaje entre pares de agujas insertadas alrededor de un tumor. La corriente generada favorece la creación de nanoporos en la membrana plasmática, desencadenando la apoptosis. Por ello, la IRE puede utilizarse de manera segura en localizaciones cercanas a estructuras vasculares delicadas, contraindicadas para el resto de técnicas termoablativas. Actualmente la IRE se emplea con éxito para la ablación de tumores en páncreas, riñón e hígado y, de manera muy extendida, como opción terapéutica focal para el cáncer de próstata. La necesidad de un manejo anestésico específico y la colocación precisa y en paralelo de múltiples agujas implican un alto nivel de complejidad, siendo necesaria una gran experiencia del equipo intervencionista. No obstante, se trata de una técnica muy prometedora con una gran capacidad inmunológica sistémica que puede provocar un efecto a distancia del tumor tratado (efecto abscopal).(AU)


Irreversible electroporation (IRE) is a non-thermal tumor ablation technique. High-voltage electrical pulses are applied between pairs of electrodes inserted around and/or inside a tumor. The generated electric current induces the creation of nanopores in the cell membrane, triggering apoptosis. As a result, IRE can be safely used in areas near delicate vascular structures where other thermal ablation methods are contraindicated. Currently, IRE has demonstrated to be a successful ablation technique for pancreatic, renal, and liver tumors and is widely used as a focal therapeutic option for prostate cancer. The need for specific anesthetic management and accurate parallel placement of multiple electrodes entails a high level of complexity and great expertise from the interventional team is required. Nevertheless, IRE is a very promising technique with a remarkable systemic immunological capability and may impact on distant metastases (abscopal effect).(AU)


Subject(s)
Humans , Male , Female , Electroporation/methods , Liver Neoplasms/diagnostic imaging , Kidney Neoplasms/diagnostic imaging , Pancreatic Neoplasms/diagnostic imaging , Immunotherapy , Radiology, Interventional , Radiology , Diagnostic Imaging , Medical Oncology , Ablation Techniques , Anesthesia/methods
8.
Int J Hyperthermia ; 41(1): 2308063, 2024.
Article in English | MEDLINE | ID: mdl-38314664

ABSTRACT

OBJECTIVE: To evaluate the complications associated with microwave ablation (MWA) in treating persistent/recurrent hyperparathyroidism (HPT) post-surgical or ablative treatments. MATERIALS AND METHODS: From January 2015 to December 2022, 87 persistent/recurrent HPT patients (primary HPT [PHPT]: secondary HPT [SHPT] = 13:74) who underwent MWA after surgical or ablative treatment were studied. Grouping was based on ablation order (initial vs. re-MWA), prior treatment (parathyroidectomy [PTX] vs. MWA), and etiology (PHPT vs. SHPT). The study focused on documenting and comparing treatment complications and analyzing major complication risk factors. RESULT: Among the 87 patients, the overall complication rate was 17.6% (15/87), with major complications at 13.8% (12/87) and minor complications at 3.4% (3/87). Major complications included recurrent laryngeal nerve (RLN) palsy (12.6%) and Horner syndrome (1.1%), while minor complications were limited to hematoma (3.4%). Severe hypocalcemia noted in 21.6% of SHPT patients. No significant differences in major complication rates were observed between initial and re-MWA groups (10.7% vs. 13.8%, p = 0.455), PTX and MWA groups (12.5% vs. 15.4%, p = 0.770), or PHPT and SHPT groups (15.4% vs. 13.5%, p > 0.999). Risk factors for RLN palsy included ablation of superior and large parathyroid glands (>1.7 cm). All patients recovered spontaneously except for one with permanent RLN palsy in the PTX group (2.1%). CONCLUSION: Complication rates for MWA post-surgical or ablative treatments were comparable to initial MWA rates. Most complications were transient, indicating MWA as a viable and safe treatment option for persistent/recurrent HPT patients.


Subject(s)
Ablation Techniques , Hyperparathyroidism, Secondary , Radiofrequency Ablation , Humans , Microwaves/adverse effects , Ablation Techniques/adverse effects , Radiofrequency Ablation/adverse effects , Hyperparathyroidism, Secondary/surgery , Paralysis/etiology , Retrospective Studies
9.
Int J Hyperthermia ; 41(1): 2313492, 2024.
Article in English | MEDLINE | ID: mdl-38369302

ABSTRACT

BACKGROUND: Despite the theoretical advantages of treating metastatic bone disease with microwave ablation (MWA), there are few reports characterizing microwave absorption and bioheat transfer in bone. This report describes a computational modeling-based approach to simulate directional microwave ablation (dMWA) in spine, supported by ex vivo and pilot in vivo experiments in porcine vertebral bodies. MATERIALS AND METHODS: A 3D computational model of microwave ablation within porcine vertebral bodies was developed. Ex vivo porcine vertebra experiments using a dMWA applicator measured temperatures approximately 10.1 mm radially from the applicator in the direction of MW radiation (T1) and approximately 2.4 mm in the contra-lateral direction (T2). Histologic assessment of ablated ex vivo tissue was conducted and experimental results compared to simulations. Pilot in vivo experiments in porcine vertebral bodies assessed ablation zones histologically and with CT and MRI. RESULTS: Experimental T1 and T2 temperatures were within 3-7% and 11-33% of simulated temperature values. Visible ablation zones, as indicated by grayed tissue, were smaller than those typical in other soft tissues. Posthumous MRI images of in vivo ablations showed hyperintensity. In vivo experiments illustrated the technical feasibility of creating directional microwave ablation zones in porcine vertebral body. CONCLUSION: Computational models and experimental studies illustrate the feasibility of controlled dMWA in bone tissue.


Subject(s)
Ablation Techniques , Catheter Ablation , Radiofrequency Ablation , Swine , Animals , Ablation Techniques/methods , Microwaves/therapeutic use , Computer Simulation , Spine/surgery , Liver/surgery , Catheter Ablation/methods
10.
Radiologia (Engl Ed) ; 66(1): 47-56, 2024.
Article in English | MEDLINE | ID: mdl-38365354

ABSTRACT

Irreversible Electroporation (IRE) is a non-thermal tumor ablation technique. High-voltage electrical pulses are applied between pairs of electrodes inserted around and/or inside a tumor. The generated electric current induces the creation of nanopores in the cell membrane, triggering apoptosis. As a result, IRE can be safely used in areas near delicate vascular structures where other thermal ablation methods are contraindicated. Currently, IRE has demonstrated to be a successful ablation technique for pancreatic, renal, and liver tumors and is widely used as a focal therapeutic option for prostate cancer. The need for specific anesthetic management and accurate parallel placement of multiple electrodes entails a high level of complexity and great expertise from the interventional team is required. Nevertheless, IRE is a very promising technique with a remarkable systemic immunological capability and may impact on distant metastases (abscopal effect).


Subject(s)
Ablation Techniques , Liver Neoplasms , Prostatic Neoplasms , Male , Humans , Ablation Techniques/methods , Electroporation/methods , Pancreas
11.
Am J Cardiol ; 212S: S42-S52, 2024 Feb 01.
Article in English | MEDLINE | ID: mdl-38368036

ABSTRACT

Alcohol septal ablation (ASA) is a well-established procedure for septal reduction therapy in patients with obstructive hypertrophic cardiomyopathy, significant at rest or provocable outflow tract gradients, and medically refractory symptoms. This percutaneous approach to relief of obstruction and eventual cardiac remodeling involves the infusion of a small quantity of ethanol into an appropriately targeted septal artery that is feeding the basal septum to create an iatrogenic and controlled focal infarction. Early akinesia is followed by subsequent thinning and remodeling, which widens the outflow tract, reducing or eliminating the obstruction. Historically, the use of ASA was reserved primarily for high-risk surgical candidates; however, more contemporary data suggest similar outcomes in the short-term and long-term safety of the procedure and overall effectiveness in relieving obstructive symptoms when it is performed in broader populations at experienced centers. Therefore, the current guidelines published in 2020 support ASA as a class 1 indication, similar to its open-heart surgical counterpart, surgical myectomy, when no concomitant significant coronary or valve surgical indication exists. This article summarizes contemporary management of patients with hypertrophic cardiomyopathy who were selected for ASA and details procedural methods and outcomes.


Subject(s)
Ablation Techniques , Cardiac Surgical Procedures , Cardiomyopathy, Hypertrophic , Humans , Treatment Outcome , Heart Septum/surgery , Ethanol/therapeutic use , Cardiomyopathy, Hypertrophic/surgery , Cardiomyopathy, Hypertrophic/diagnosis , Cardiac Surgical Procedures/methods , Ablation Techniques/methods
12.
Radiol Med ; 129(2): 291-306, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38302831

ABSTRACT

BACKGROUND: The percutaneous thermal ablation techniques (pTA) are radiofrequency ablation, cryoablation, and microwave ablation, suitable for the treatment of bone oligometastases. Magnetic resonance-guided focused ultrasound (MRgFUS) is a noninvasive ablation technique. OBJECTIVES: To compare the effectiveness and safety of MRgFUS and pTA for treating bone oligometastases and their complications. METHODS: Studies were selected with a PICO/PRISMA protocol: pTA or MRgFUS in patients with bone oligometastases; non-exclusive curative treatment. Exclusion criteria were: primary bone tumor; concurrent radiation therapy; palliative therapy; and absence of imaging at follow-up. PubMed, BioMed Central, and Scopus were searched. The modified Newcastle-Ottawa Scale assessed articles quality. For each treatment (pTA and MRgFUS), we conducted two separate random-effects meta-analyses to estimate the pooled effectiveness and safety. The effectiveness was assessed by combining the proportions of treated lesions achieving local tumor control (LTC); the safety by combining the complications rates of treated patients. Meta-regression analyses were performed to identify any outcome predictor. RESULTS: A total of 24 articles were included. Pooled LTC rate for MRgFUS was 84% (N = 7, 95% CI 66-97%, I2 = 74.7%) compared to 65% of pTA (N = 17, 95% CI 51-78%, I2 = 89.3%). Pooled complications rate was similar, respectively, 13% (95% CI 1-32%, I2 = 81.0%) for MRgFUS and 12% (95% CI 8-18%, I2 = 39.9%) for pTA, but major complications were recorded with pTA only. The meta-regression analyses, including technique type, study design, tumor, and follow-up, found no significant predictors. DISCUSSION: The effectiveness and safety of the two techniques were found comparable, even though MRgFUS is a noninvasive treatment that did not cause any major complication. Limited data availability on MRgFUS and the lack of direct comparisons with pTA may affect these findings. CONCLUSIONS: MRgFUS can be a valid, safe, and noninvasive treatment for bone oligometastases. Direct comparison studies are needed to confirm its promising benefits.


Subject(s)
Ablation Techniques , Bone Neoplasms , High-Intensity Focused Ultrasound Ablation , Humans , High-Intensity Focused Ultrasound Ablation/methods , Bone Neoplasms/diagnostic imaging , Bone Neoplasms/surgery , Bone Neoplasms/secondary , Palliative Care , Magnetic Resonance Spectroscopy , Treatment Outcome
13.
Am J Cardiol ; 216: 54-62, 2024 Apr 01.
Article in English | MEDLINE | ID: mdl-38402924

ABSTRACT

Alcohol septal ablation (ASA) is performed for symptomatic drug-refractory hypertrophic obstructive cardiomyopathy to reduce the left ventricular outflow tract pressure gradient (LVOTPG) by injecting ethanol into a septal branch that perforates the septal bulge. The target septal branches usually arise directly from the left anterior descending (LAD) artery; however, vessels from a non-LAD artery can be selected in some cases. This study aimed to compare the effectiveness and safety between ASA performed using a septal branch arising from a non-LAD artery and a branch arising from the LAD artery. This single-center, retrospective, observational cohort study comprised patients with hypertrophic obstructive cardiomyopathy who underwent ASA at the Gifu Heart Centre between 2011 and 2022. The effectiveness and safety of ASA using the 2 artery types were compared. The primary end points were LVOTPG and procedure success, determined as LVOTPG <30 mm Hg after 1 year. Of 33 patients (mean age 66.4 ± 13.0 years, 13 men), 18 patients who underwent ASA using only LAD branches and 15 patients who underwent ASA using only non-LAD branches demonstrated no significant difference in the decrease in LVOTPG during the follow-up period (-99.1 ± 47.4 mm Hg/year vs -75.7 ± 39.2 mm Hg/year, respectively, p = 0.19). The procedure success at 1 year was not significantly different between the 2 groups (93.3% and 84.6%, respectively, p = 0.58). ASA performed using septal branches from non-LAD arteries could be an alternative treatment approach when appropriate septal branches are missing or desirable effects cannot be obtained from ASA using LAD branches.


Subject(s)
Ablation Techniques , Cardiomyopathy, Hypertrophic , Aged , Humans , Male , Middle Aged , Coronary Vessels/diagnostic imaging , Coronary Vessels/surgery , Ethanol/therapeutic use , Heart Septum/surgery , Retrospective Studies , Treatment Outcome , Female
15.
J Vasc Surg Venous Lymphat Disord ; 12(1): 101681, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37703943

ABSTRACT

OBJECTIVE: The aim of this study was to summarize the existing evidence for the treatment of saphenous veins >10 mm in diameter, to determine whether there were vein size limits for treatment modalities, and to determine if there are specific technical considerations for treatment of large veins. METHODS: We searched the literature for reports of treatment methods and outcomes for patients with large-diameter saphenous veins treated with various ablation methods between 1993 and 2023. These studies were evaluated for the size of the vein determined as "large diameter," type of ablation method, study type, outcomes, adverse events, and any technical considerations noted. A systematic review was conducted and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology. The COVIDENCE software was used for full-text screening and data extraction. Three reviewers reviewed the data, and the content expert served as the tiebreaker. RESULTS: Seventy-one records were identified, of which 24 studies were deemed appropriate for extraction. Most of the studies identified reported outcomes of endovenous thermal ablation modalities. There were fewer studies on non-thermal, non-tumescent techniques, and these studies reported an overall lower occlusion rate compared with endovenous thermal ablation techniques. CONCLUSIONS: Large head-to-head trials or randomized controlled that compare all the modalities over a long follow-up duration are yet to be performed. In the existing literature, there is considerable heterogeneity in terms of the study size, design, definition of large veins, site of vein measurement, and follow-up periods, making it challenging to make fair comparisons and draw firm conclusions. Currently available evidence supports the use of endothermal ablation techniques for the treatment of veins >10 mm in diameter as they have a more favorable efficacy and safety profile and have a larger body of evidence available compared with non-thermal, non-tumescent techniques or surgery.


Subject(s)
Ablation Techniques , Varicose Veins , Venous Insufficiency , Humans , Saphenous Vein/diagnostic imaging , Saphenous Vein/surgery , Ablation Techniques/adverse effects , Ablation Techniques/methods , Varicose Veins/diagnostic imaging , Varicose Veins/surgery , Venous Insufficiency/diagnostic imaging , Venous Insufficiency/surgery , Femoral Vein , Treatment Outcome
16.
Phys Med Biol ; 69(2)2024 Jan 12.
Article in English | MEDLINE | ID: mdl-38041873

ABSTRACT

Objective. Histotripsy is a cavitation-based ultrasound ablation method in development for multiple clinical applications. This work investigates the effects of pulse repetition frequency (PRF) on bubble cloud characteristics and ablative capabilities for histotripsy using single-cycle pulsing methods.Approach.Bubble clouds produced by a 500 kHz histotripsy system at PRFs from 0.1 to 1000 Hz were visualized using high-speed optical imaging in 1% agarose tissue phantoms at peak negative pressures,p-, of 2-36 MPa.Main results.Results showed a decrease in the cavitation cloud threshold with increasing PRF, ranging from 26.7 ± 0.5 MPa at 0.1 Hz to 15.0 ± 1.9 MPa at 1000 Hz. Bubble cloud analysis showed cavitation clouds generated at low PRFs (0.1-1 Hz) were characterized by consistently dense bubble clouds (41.7 ± 2.8 bubbles mm-2at 0.1 Hz), that closely matched regions of the focus above the histotripsy intrinsic threshold. Bubble clouds formed at higher PRFs measured lower cloud densities (23.1 ± 4.0 bubbles mm-2at 1000 Hz), with the lowest density measured for 10 Hz (8.8 ± 4.1 bubbles mm-2). Furthermore, higher PRFs showed increased pulse-to-pulse correlation, characteristic of cavitation memory effects; however, bubble clouds still filled the entire volume of the focus due to their initial density and enhanced bubble expansion from the restimulation of residual nuclei at the higher PRFs. Histotripsy ablation assessed through lesion analysis in red blood cell (RBC) phantoms showed higher PRFs generated lesions with lower adherence to the initial focal region compared to low PRF ablations; however, no trend of decreasing ablation efficiency with PRF was observed, with similar efficiencies observed for all the PRFs tested in this study.Significance.Notably, this result is different than what has previously been shown for shock-scattering histotripsy, which has shown decreased ablation efficiencies at higher PRFs. Overall, this study demonstrates the essential effects of PRF on single-cycle histotripsy procedures that should be considered to help guide future histotripsy pulsing strategies.


Subject(s)
Ablation Techniques , High-Intensity Focused Ultrasound Ablation , Lithotripsy , High-Intensity Focused Ultrasound Ablation/methods , Lithotripsy/methods , Ultrasonography , Phantoms, Imaging
17.
Rev Port Cardiol ; 43(1): 13-19, 2024 Jan.
Article in English, Portuguese | MEDLINE | ID: mdl-37423311

ABSTRACT

INTRODUCTION AND OBJECTIVES: Patients with hypertrophic obstructive cardiomyopathy (HOCM) that remain symptomatic despite optimized medical therapy often undergo alcohol septal ablation (ASA). One of the most frequent complications is complete heart block (CHB), requiring a permanent pacemaker (PPM) in variable rates of up to 20% of patients. The long-term impact of PPM implantation in these patients remains unclear. This study aimed to evaluate the long-term clinical outcomes in patients who implant PPM after ASA. METHODS: Patients who underwent ASA at a tertiary center were consecutively and prospectively enrolled. Patients with previous PPM or implantable cardio-defibrillator were excluded from this analysis. Patients with and without PPM implantation after ASA were compared based on their baseline characteristics, procedure data and three-year primary endpoint of composite of all-cause mortality and hospitalization and secondary endpoint of composite of all-cause mortality and cardiac cause hospitalization. RESULTS: Between 2009 and 2019, 109 patients underwent ASA, 97 of whom were included in this analysis (68% female, mean age 65.2 years old). 16 patients (16.5%) required PPM implantation for CHB. In these patients, no vascular access, pacemaker pocket or pulmonary parenchyma complications were noted. The baseline characteristics of comorbidities, symptoms, echocardiographic and electrocardiographic findings were identical in the two groups, with higher mean age (70.6±10.0 years vs. 64.1±11.9 years) and lower beta-blocker therapy rate (56% vs. 84%) in the PPM group. Procedure-related data showed higher creatine kinase (CK) peaks in the PPM group (1692 U/L vs. 1243 U/L), with no significant difference in the alcohol dose. At three years after ASA procedure, there were no differences in the primary and secondary endpoints between the two groups. CONCLUSIONS: Permanent pacemaker after ASA induced CHB do not affect long term prognosis in hypertrophic obstructive cardiomyopathy patients.


Subject(s)
Ablation Techniques , Cardiomyopathy, Hypertrophic , Pacemaker, Artificial , Humans , Female , Aged , Middle Aged , Aged, 80 and over , Male , Heart Septum/surgery , Echocardiography , Cardiomyopathy, Hypertrophic/surgery , Pacemaker, Artificial/adverse effects , Heart Block/etiology , Heart Block/therapy , Treatment Outcome , Ablation Techniques/adverse effects , Ablation Techniques/methods
18.
J Vasc Surg Venous Lymphat Disord ; 12(2): 101679, 2024 Mar.
Article in English | MEDLINE | ID: mdl-37708939

ABSTRACT

OBJECTIVE: Varicose veins have a significant impact on quality of life and can commonly occur in the thigh and calves. However, there has been no large-scale investigation examining the relationship between anatomic distribution and outcomes after varicose vein treatment. This study sought to compare below-the-knee (BTK) and above-the-knee (ATK) varicose vein treatment outcomes. METHODS: Employing the Vascular Quality Initiative Varicose Vein Registry, 13,731 patients undergoing varicose vein ablation for either BTK or ATK lesions were identified. Outcomes were assessed using patient-reported outcomes (PROs) and the Venous Clinical Severity Score (VCSS). Continuous variables were compared using the t-test, and categorical variables were analyzed using the χ2 test. Multivariable logistic regression was used to estimate the odds of improvement after intervention. The multivariable model controlled for age, gender, race, preoperative VCSS composite score, and history of deep vein thrombosis. RESULTS: Patients who received below-knee treatment had a lower preoperative VCSS composite (7.0 ± 3.3 vs 7.7 ± 3.3; P < .001) and lower PROs composite scores (11.1 ± 6.4 vs 13.0 ± 6.6; P < .001) compared with those of patients receiving above-knee treatment. However, on follow-up, patients receiving below-knee intervention had a higher postoperative VCSS composite score (4.4 ± 3.3 vs 3.9 ± 3.5; P < .001) and PROs composite score (6.1 ± 4.4 vs 5.8 ± 4.5; P = .007), the latter approaching statistical significance. Patients receiving above-knee interventions also demonstrated more improvement in both composite VCSS (3.8 ± 4.0 vs 2.9 ± 3.7; P < .001) and PROs (7.1 ± 6.8 vs 4.8 ± 6.6; P < .001). Multivariable logistic regression analysis similarly revealed that patients receiving above-knee treatment had significantly higher odds of improvement in VCSS composite in both the unadjusted (odds ratio [OR], 1.45; 95% confidence interval [CI], 1.28-1.65; P < .001 and adjusted (OR, 1.31; 95% CI, 1.14-1.50; P < .001) models. Patients receiving above-knee treatment also had a significantly higher odds of reporting improvement in PROs composite in both the unadjusted (OR, 1.85; 95% CI, 1.64-2.11; P < .001) and adjusted (OR, 1.65; 95% CI, 1.45-1.88; P < .001) models. CONCLUSIONS: Treatment region has a significant association with PROs and VCSS composite scores after varicose vein interventions. Preoperatively, there were significant differences in the composite scores of VCSS and PROs with patients receiving BTK treatment exhibiting less severe symptoms. Yet, the association appeared to reverse postoperatively, with those receiving BTK treatments exhibiting worse PROs, worse VCSS composites scores, and less improvement in VCSS composite scores. Therefore, BTK interventions pose a unique challenge compared with ATK interventions in ensuring commensurate clinical improvement after treatment.


Subject(s)
Ablation Techniques , Varicose Veins , Venous Insufficiency , Humans , Leg , Quality of Life , Saphenous Vein/surgery , Treatment Outcome , Varicose Veins/diagnostic imaging , Varicose Veins/surgery , Venous Insufficiency/therapy
19.
Endocrine ; 83(2): 330-341, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37658978

ABSTRACT

BACKGROUND: The global prevalence of thyroid cancer is on the rise. About one-third of newly diagnosed thyroid cancer cases comprise low-risk papillary thyroid cancer (1.5 cm or more minor). While surgical removal remains the prevailing approach for managing low-risk papillary thyroid cancer (LPTC) in patients, other options such as active surveillance (AS), radiofrequency ablation (RFA), microwave ablation (MWA), and laser ablation (LA) are also being considered as viable alternatives. This study evaluated and compared surgical thyroid resection (TSR) versus non-surgical (NS) methods for treating patients with LPTC. METHODS: The study encompassed an analysis of comparisons between surgical thyroid resection (TSR) and alternative approaches, including active surveillance (AS), radiofrequency ablation (RFA), microwave ablation (MWA), or laser ablation (LA). The focus was on patients with biopsy-confirmed low-risk papillary thyroid cancer (LPTC) of less than 1.5 cm without preoperative indications of local or distant metastasis. The primary outcomes assessed were recurrence rates, disease-specific mortality, and quality of life (QoL). Data were collected from prominent databases, including Cochrane Database, Embase, MEDLINE, and Scopus, from inception to June 3rd, 2020. The CLARITY tool was utilized to evaluate bias risk. The analysis involved odds ratios (OR) with 95% confidence intervals (CI) for dichotomous outcomes, as well as mean differences (MD) and standardized mean differences (SMD) for continuous outcomes. The study is registered on PROSPERO under the identifier CRD42021235657. RESULTS: The study incorporated 13 retrospective cohort studies involving 4034 patients. Surgical thyroid resection (TSR), active surveillance (AS), and minimally invasive techniques like radiofrequency ablation (RFA), microwave ablation (MWA), and laser ablation (LA) were performed in varying proportions of cases. The analysis indicated that specific disease mortality rates were comparable among AS, MWA, and TSR groups. The risk of recurrence, evaluated over different follow-up periods, showed no significant differences when comparing AS, RFA, MWA, or LA against TSR. Patients undergoing AS demonstrated better physical health-related quality of life (QoL) than those undergoing TSR. However, no substantial differences were observed in the overall mental health domain of QoL when comparing AS or RFA with TSR. The risk of bias was moderate in nine studies and high in four. CONCLUSION: Low-quality evidence indicates comparable recurrence and disease-specific mortality risks among patients with LPTC who underwent ablation techniques or active surveillance (AS) compared to surgery. Nevertheless, individuals who opted for AS exhibited enhanced physical quality of life (QoL). Subsequent investigations are warranted to validate these findings.


Subject(s)
Ablation Techniques , Catheter Ablation , Thyroid Neoplasms , Humans , Quality of Life , Catheter Ablation/methods , Thyroid Cancer, Papillary , Retrospective Studies , Watchful Waiting , Treatment Outcome
20.
Radiology ; 309(3): e230431, 2023 Dec.
Article in English | MEDLINE | ID: mdl-38051187

ABSTRACT

Two cases involving patients diagnosed with localized prostate cancer and treated with MRI-guided focal therapies are presented. Patient selection procedures, techniques, outcomes, challenges, and future directions of MRI-guided focal therapies, as well as their role in the treatment of low- to intermediate-risk localized prostate cancer, are summarized.


Subject(s)
Ablation Techniques , Prostatic Neoplasms , Male , Humans , Prostatic Neoplasms/diagnostic imaging , Prostatic Neoplasms/surgery , Magnetic Resonance Imaging/methods , Ablation Techniques/methods
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