Conventional RF Research Articles

Value of using ultrasonic shears in reducing seroma formation after axillary lymph node dissection in breast cancer patients

BackgroundAxillary lymph node dissection (ALND) is an essential step in the management of breast cancer. ALND is conventionally performed using radio frequency electrosurgery. The post-operative complications of utilizing such energy (such as prolonged drainage time, seroma, or infection) lead to prolonged recovery. Hence, it may delay the initiation of adjuvant chemo/radiotherapy for this critical category of patients. Using ultrasound shears provides a wide spectrum of tissue effects via mechanical oscillation. The absence of an electric circuit in ultrasound shears reduces thermal injury and accordingly cellular damage.ObjectiveComparing utilization of ultrasound shears in axillary lymph node dissection to conventional radio frequency electrosurgery in terms of operative time, post-operative drainage amount and days, post-operative pain, the incidence of seroma or infection, and lymph node yield.MethodsThis study is a randomized control trial. It includes 56 breast cancer ALND cases performed in conjunction with either BCS or MRM; being upfront surgery cases or post-neoadjuvant therapy cases, 28 patients underwent ALND using ultrasound shears and 28 underwent ALND using radio frequency electrosurgery.ResultsThe mean age of the study population was 51 ± 11.7 years, with a mean BMI of 39. The mean operative time in the ultrasound shear group was 29.4. ± 7.6 min and 31.6 ± 5.1 min in the conventional group. The mean amount of drainage in the ultrasound shear group was 319.6 ± 75.4 ml and 407.5 ± 75.2 ml in the conventional group. The mean drainage days in the ultrasound shear group were 8 ± 1 day and 12 ± 2.2 days in the conventional group. Seroma formation was recorded in 6 of the ultrasound shear groups and 9 in the conventional group. Seroma followed by infection was found in 10% of the ultrasound shear group versus 21% in the conventional group. Seroma formation and wound infection were significantly related to the conventional group (p-value = 0.01).ConclusionOur study recommends the utilization of ultrasound shears in ALND as it is a safe and accurate method that allows faster post-operative recovery with shorter drainage time and lower incidence of seroma or infection, without affecting operative time or lymph node yield.Trial registrationTrial no.: PACTR202402831197428. Date of approval: 19/02/2024

LI-FI Performance Analysis in Various Aquatic Environments for Reliable Underwater Communication

The ability to communicate reliably and quickly underwater has been one of the driving forces behind the development of alternative technologies to conventional radio frequency systems. This study explores the performance of Light Fidelity (Li-Fi), a high-speed optical wireless communication technology, in diverse aquatic environments like fresh water, salt water, and turbid water. It evaluates key parameters like signal attenuation, data rate, bit error rate, and transmission range. Results show that Li-Fi offers significant advantages in bandwidth and data rate over traditional methods, but its efficiency is highly dependent on environmental conditions. The study recommends optimizing Li-Fi systems for reliable underwater communication, paving the way for enhanced underwater networking and data transmission applications.

Comparison of radiofrequency thermocoagulation of ganglion Impar with block using a combination of local anaesthetic and steroid in chronic perineal pain

Abstract Background and Aims: Chronic perineal pain (CPP) is the anorectal and perineal pain without underlying organic disease. The prevalence of CPP is 6–18%. The etiology for CPP may be idiopathic, benign, or malignant. We compared radiofrequency thermocoagulation of ganglion Impar with block using a combination of local anaesthetic and steroid for management of chronic perineal pain, with respect to pain relief, patients’ self-reported belief about the efficacy of treatment, and side effects or complications, if any. Material and Methods: Forty patients attending the Pain Management Centre of either sex in the age group of 20–70 years with history, physical examination, and pain patterns consistent with chronic perineal pain, who had been investigated to rule out malignancy and failed to respond to 6 weeks of conservative treatment with a combination of analgesics, anti-inflammatory drugs, neuromodulators, and physiotherapy, were enrolled in the study. The patients were randomly divided into two groups of 20 each using a computer-generated randomization number table. Group-I (n = 20): Patients were administered ganglion Impar block using a drug mixture comprising of 8 ml of 0.25% bupivacaine plus 80 mg of triamcinolone acetate under fluoroscopic guidance. Group II (n = 20): Patients received conventional radiofrequency thermocoagulation of ganglion Impar at 80 degree Celsius for 90 seconds under fluoroscopic guidance. Outcome assessment was done after minimally invasive pain and spine intervention (MIPSI) with evaluation of pain using the Numeric Rating Scale (0–10), patients’ self-reported belief about the efficacy of treatment using Patient Global Impression of Change (PGI-C), and side effects or complications, if any. Results: The majority of the patients in our study were in the age group of 40–50 years, and 80% of the patients were females and weighed 60–70 kg. The majority of the patients in our study had history of trauma, which led to coccygodynia. There was statistically and clinically significant improvement in pain score after ganglion Impar block in both the groups at all time intervals during the study period (P < 0.05). Patients’ self-reported belief about efficacy as per PGI-C was clinically and statistically better in group II as compared to group I at all time intervals throughout the study period (P < 0.005). Four patients in group I required second ganglion Impar block during the 12 months study period. The most common side effect was temporary pain on injection. Conclusions: Both the techniques of MIPSI, that is, fluoroscope-guided ganglion Impar block using corticosteroid and local anaesthetic and radiofrequency thermocoagulation, are effective and provide good pain relief to the symptomatic patients. With respect to improvement in pain relief and patients’ self-reported belief about the efficacy of treatment and side effects or complications, fluoroscope-guided ganglion Impar radiofrequency thermocoagulation is better as compared to fluoroscope-guided ganglion Impar block using corticosteroids and local anesthetics.

MR‐zero meets FLASH – controlling the transient signal decay in gradient‐ and RF‐spoiled gradient echo sequences

AbstractPurposeThe complex signal decay during the transient FLASH MRI readout can lead to artifacts in magnitude and phase images. We show that target‐driven optimization of individual RF flip angles and phases can realize near‐ideal signal behavior and mitigate artifacts.MethodsThe differentiable end‐to‐end optimization framework MR‐zero is used to optimize RF trains of the FLASH sequence. We focus herein on minimizing deviations from the ideally spoiled signal by using a mono‐exponential Look–Locker target. We first obtain the transient FLASH signal decay substructure, and then minimize the deviation to the Look–Locker decay by optimizing the individual (i) flip angles, (ii) RF phases, and (iii) flip angles and RF phases. Comparison between measurement and simulation is performed using Pulseq in 1D and 2D.ResultsWe were able to reproduce the complex substructure of the transient FLASH signal decay. All three optimization objectives can bring the real FLASH signal closer to the ideal case, with best results when both flip angles and RF phases are adjusted jointly. This solution outperformed all tested conventional quadratic RF cyclings in terms of (i) matching the Look–Locker target signal, (ii) phase stability, (iii) point spread functions ideality, (iv) robustness against parameter changes, and (v) magnitude and phase image quality. Other target functions for the signal could as well be realized, yet their response is not as general as for the Look–Locker target and needs to be optimized for a specific context.ConclusionIndividual flip angle and RF phase optimization improves the transient signal decay of FLASH MRI sequences.

Arrhythmia

The basic principles of atrial fibrillation(AF)treatment are stroke prevention with appropriate anticoagulation, rhythm and rate control with drugs, and non-pharmacological therapy. The current guidelines have been presented. Non-pharmacological treatment(catheter ablation)for AF, originally developed to eliminate motivational symptoms, has been shown to improve life outcomes, and indications for ablation are expanding rapidly. Catheter ablation has evolved remarkably from conventional radiofrequency to balloon ablation. Minimal complications are expected to occur with pulsed-field ablation. Ablation strategies for paroxysmal AF are almost established and approaches for persistent AF are becoming increasingly important. Surgical approaches have also evolved significantly, with robotic surgery, the thoracoscopic Wolf-Ohtsuka procedure, and minimally invasive cardiac surgery, becoming less invasive. Future studies should prioritize a system for better function and treatment options for the heart team.

VLC performance in underground vehicular tunnels

In recent years, the integration of intelligent transportation systems (ITS) has gained popularity as a means of enhancing the safety of roadways and underground tunnels and reducing traffic congestion. Given the fact that conventional radio frequency (RF) communication systems are vulnerable to significant limitations as a result of a variety of factors, including signal attenuation and interference, which affect their application, the emerging visible light communication (VLC) technology is an exciting potential candidate for facilitating wireless access in such environments. This study investigates the deployment of VLC systems in underground vehicular tunnels involving a handover strategy based on the software-defined network (SDN) approach, with the objective of addressing the fundamental challenges faced by communication systems in such scenarios. The Optisystem software is used to simulate and investigate the performance of the proposed system, which is based on orthogonal frequency division multiplexing (OFDM) technology in both line-of-sight (LOS) and non-line-of-sight (NLOS) conditions. The simulated scenario is capable of achieving a data rate of 10 Gbps within a link range of 3 meters in the LOS approach. In the NLOS propagation model, a data rate of 2 Gbps can be attained without any error. The simulation results reveal a particular perspective on the viability of VLC systems in improving the communication infrastructure in underground vehicular tunnels and promoting efficient tunnel operations. The evaluation of the simulated system is conducted based on bit error rate (BER), signal-to-noise ratio (SNR), and the constellation diagram.

In vitro characterization of radiofrequency ablation lesions in equine and swine myocardial tissue

Radiofrequency ablation is a promising technique for arrhythmia treatment in horses. Due to the thicker myocardial wall and higher blood flow in horses, it is unknown if conventional radiofrequency settings used in human medicine can be extrapolated to horses. The study aim is to describe the effect of ablation settings on lesion dimensions in equine myocardium. To study species dependent effects, results were compared to swine myocardium. Right ventricular and right and left atrial equine myocardium and right ventricular swine myocardium were suspended in a bath with circulating isotonic saline at 37 °C. The ablation catheter delivered radiofrequency energy at different-power-duration combinations with a contact force of 20 g. Lesion depth and width were measured and lesion volume was calculated. Higher power or longer duration of radiofrequency energy delivery increased lesion size significantly in the equine atrial myocardium and in equine and swine ventricular myocardium (P < 0.001). Mean lesion depth in equine atrial myocardium ranged from 2.9 to 5.5 mm with a diameter ranging from 6.9 to 10.1 mm. Lesion diameter was significantly larger in equine tissue compared to swine tissue (P = 0.020). Obtained data in combination with estimated wall thickness can improve lesion transmurality which might reduce arrhythmia recurrence. Optimal ablation settings may differ between species.

Exploring the Potential of Intralesional Radiofrequency Ablation in Dermatology: A Case Series

Intralesional radiofrequency (ILRF) ablation is a novel and safe dermatosurgical technique which, unlike conventional radiofrequency, minimizes the risk of epidermal scarring by precisely targeting the reticular dermis. ILRF’s simplicity, cost-effectiveness, and cosmetic advantages make it an attractive option for treating various skin conditions. While ILRF has found applications in various fields beyond dermatology, there exists a scarcity of data concerning its safety and effectiveness in dermatology. We successfully utilized this novel technique to manage conditions such as lymphangioma circumscriptum and molluscum contagiosum, highlighting the promising impact and benefits of this approach.

Long-term effects of conventional radiofrequency in cases of trigeminal neuralgia

Objective: Trigeminal neuralgia (TN) is defined as severe, episodic pain occurring in one or more branches of the trigeminal nerve. Due to its long-term effect, radiofrequency thermocoagulation (RFT) is used as a first-line treatment. The first choice in the treatment of classical trigeminal neuralgia patients is medical treatment. Additionally, pregabalin and gabapentin are frequently used drugs. Surgical treatment is an option for Trigeminal Neuralgia that cannot be treated with medication, but there is no single method for this. Various surgical methods, such as Trigeminal Radiofrequency (RF) rhizotomy may be effective in treatment. Material and metods: The procedure is performed under operating room conditions and radiological imaging guidance. The patient is placed in the supine position, an IV line is established, and monitoring is initiated. After local field cleaning and sterile draping, optimal imaging is achieved using C-arm fluoroscopy with an ipsilateral 15° oblique and 30° caudal angle. A 22-gauge, 100 mm RF needle with a 5 mm active tip is directed towards the foramen ovale, and the tunnel view is checked. Results: In our study, the minimum age was 41 and the maximum age was 68. Additionally, 9 of the patients were female, and 2 were male. In our series, 9 patients had mandibular nerve involvement, and 2 had maxillary nerve involvement. In our series, 6 patients were using carbamazepine, 4 were using pregabalin, and 1 was using gabapentin. Medication treatment was discontinued in all patients after the procedure. As shown in Table 1, the VAS score decreased to 0 in 6 patients on the 15th day, to 2 in 4 patients, and to 1 in 1 patient. The VAS score exceeded 5 in 1 patient in the 2nd year and in 5 patients in the 4th year, and conventional RFT was repeated for these patients. The VAS score decreased to 0 in 6 patients on the 15th day, to 2 in 4 patients, and to 1 in 1 patient. The VAS score exceeded 5 in 1 patient in the 2nd year and in 5 patients in the 4th year, and conventional RFT was repeated for these patients. Pregabalin 75 mg was started for all patients between the recurrence of pain and the interventional procedure, and it was discontinued once the pain decreased after the procedure. No side effects were observed in the patients. Conclusion: The treatment of trigeminal neuralgia includes medical, surgical, and percutaneous interventional options. Conventional RF thermocoagulation is the first choice among other percutaneous interventional and surgical treatment options in TN treatment due to its selective lesion formation, minimally invasive nature, high success rate, low complication rate, and low cost.

Conventional versus high-voltage, long-term pulse Radiofrequency of ganglion impar in perineal pain with advanced rectal cancer: a Randomized, double-blind controlled trial

Study objectiveAdvanced rectal cancer is a common cause of perineal pain and research on the use of radiofrequency therapy for the treatment of this pain is limited. In the present study, we aimed to compare the effectiveness and safety of conventional radiofrequency (CRF) and high-voltage long-term pulsed radiofrequency (H-PRF) of radiofrequency therapy in the management of perineal pain in advanced rectal cancer.DesignRandomized, Double-Blind Controlled Trial.SettingSichuan Cancer Hospital & Institute and Yanjiang District People’s Hospital in Sichuan, China.ParticipantsA total of 72 patients with advanced rectal cancer experiencing perineal pain who were accepted for radiofrequency treatment.InterventionsPatients were assigned randomly (1:1) assigned to either the group CRF or H-PRF in a double-blind trial.Measurements and main resultsThe primary focus was on assessing perineal pain using numeric rating scales (NRS) scores at various time points. Secondary outcomes included the duration of maintaining a sitting position, depression scores, sleep quality, consumption of Oral Morphine Equivalent and Pregabalin, and the incidence of perineal numbness. A total of 57 patients (28 patients in the group CRF and 29 patients in the group H-PRF) were investigated. At all observation time points postoperatively, both groups of patients exhibited significant reductions in pain, enhancements in depression, improvements in sleep quality, and increased duration of sitting compared to their baseline measurements (P<0.05). During the 3 months and 6 months follow-up period, the group CRF exhibited significant reduction in pain, improvement in depression, sleep quality, and increased the time of keeping a sitting position compared with the group H-PRF (P<0.05). The consumption of oral morphine equivalent and Pregabalin as well as the incidence of perineal numbness were not significantly different between groups (P > 0.05).ConclusionOur results demonstrate that application of CRF and H-PRF in ganglion impar to reduce perineal pain and improve the quality of life of patients with advanced rectal cancer is safe and effective. However, the long-term effect of CRF is better compared with that of H-PRF.Trial registrationhttps://www.chictr.org.cn/ (ChiCTR2200061800) on 02/07/2022. This study adheres to CONSORT guidelines.

Achieving Electron Capture Dissociation in the Radio Frequency Linear Ion Trap without the Assistance of a Magnetic Field─A Simulation Study.

It is extremely difficult to inject a low-energy electron beam into a conventional radiofrequency (RF) linear ion trap for electron capture dissociation (ECD) without using a magnetic field to focus the electrons. In this study, the dynamic process of electrons in an RF field during their injection and transmission through a linear ion trap was simulated to determine the range of the RF phase where the electrons can be decelerated to meet the energy requirement for ECD. The ECD time window was expanded by applying a time-dependent compensation voltage to the cathode. The relationship between the cathode voltage and the phase of the RF voltage was determined. The ECD time window was increased to 49.4% of the total RF cycle after applying a compensation voltage. Between the phases of RF voltage of 0 and 0.975 π, at least 98.7% of electrons can be injected into the ECD reaction zone, and 94% of them had an energy less than 3 eV. The range of electron energy can also easily be shifted upward to enable hot electron capture dissociation.

Shortened radiofrequency delivery time to optimize efficiency and safety of pulmonary vein isolation with the radiofrequency balloon: insights from the COLLABORATE registry.

Previous clinical studies on pulmonary vein isolation (PVI) with a radiofrequency balloon (RFB) reported safe and effective procedures using conventional ablation settings with 20/60 s RF delivery via posterior/anterior (PST/ANT) electrodes. The latest evidence suggests that reducing the application time to 15 s (s) on the posterior wall when facing the oesophageal region is as effective as applying 20 s. To prospectively assess whether reducing RF time on PST/ANT segments to 15/45 s can ensure sufficient quality of lesion metrics and compare the new shortened ablation settings with the conventional one in terms of safety, and effectiveness at 1-year. A total of 641 patients from seven European centres were enrolled in a collaborative registry, with 374 in the conventional RF delivery group and 267 in the shortened RF delivery group. Procedural outcomes, lesion metrics, and safety profiles were assessed and compared between the groups. Freedom of any atrial tachycarrythmias at one year was 85.4% and 88.2% in the SHRT and CONV groups, respectively. The shortened RF delivery strategy was associated with significantly shorter procedure times (median 63.5 vs. 96.5 min, P < 0.001) and shortened fluoroscopy exposure (median 10.0 vs. 14.0 min, P < 0.001) compared to conventional delivery. Efficacy metrics, including first-pass isolation rates and time to isolation, were comparable between groups. Shortened RF delivery was associated with a lower incidence of procedural complications (1.4% vs. 5.3%, P = 0.04) and optimized thermal characteristics. Analyses from the COLLABORATE registry demonstrate that shortening RF energy delivery times to 15/45 s (PST/ANT) during PVI with the RFB resulted in comparable freedom from recurrent atrial tachyarrhythmia compared to conventional delivery times with comparable efficiency and safety.

Cardiac-gated spectroscopic photoacoustic imaging for ablation-induced necrotic lesion visualization.

Radiofrequency (RF) ablation is a minimally invasive therapy for atrial fibrillation. Conventional RF procedures lack intraoperative monitoring of ablation-induced necrosis, complicating assessment of completeness. While spectroscopic photoacoustic (sPA) imaging shows promise in distinguishing ablated tissue, multi-spectral imaging is challenging in vivo due to low imaging quality caused by motion. Here, we introduce a cardiac-gated sPA imaging (CG-sPA) framework to enhance image quality using a motion-gated averaging filter, relying on image similarity. Necrotic extent was calculated based on the ratio between spectral unmixed ablated tissue contrast and total tissue contrast, visualizing as a continuous color map to highlight necrotic area. The validation of the concept was conducted in both ex vivo and in vivo swine models. The ablation-induced necrotic lesion was successfully detected throughout the cardiac cycle through CG-sPA imaging. The results suggest the CG-sPA imaging framework has great potential to be incorporated into clinical workflow to guide ablation procedures intraoperatively.

Recovery of hydrogen plasma at the sub-nanosecond timescale in a plasma-wakefield accelerator

Plasma wakefield acceleration revolutionized the field of particle accelerators by generating gigavolt-per-centimeter fields. To compete with conventional radio-frequency (RF) accelerators, plasma technology must demonstrate operation at high repetition rates, with a recent research showing feasibility at megahertz levels using an Argon source that recovered after about 60 ns. Here we report about a proof-of-principle experiment that demonstrates the recovery of a Hydrogen plasma at the sub-nanosecond timescale. The result is obtained with a pump-and-probe setup and has been characterized for a wide range of plasma densities. We observed that large plasma densities reestablish their initial state soon after the injection of the pump beam ( < 0.7 ns). Conversely, at lower densities we observe the formation of a local dense plasma channel affecting the probe beam dynamics even at long delay times ( > 13 ns). The results are supported with numerical simulations and represent a step forward for the next-generation of compact high-repetition rate accelerators.

The Feasibility, Safety and Outcome of Very High-Power Short Duration Radiofrequency Ablation in Pulmonary Vein Isolation: A Real-World Observation Study.

Pulmonary vein isolation (PVI) ablation is the established gold standard therapy for patients with symptomatic drug refractory atrial fibrillation (AF). Advancements in radiofrequency (RF) ablation, have led to the development of the novel contact force-sensing temperature-controlled very high-power short-duration (vHPSD) RF ablation. This setting delivers 90 W for up to 4 seconds with a constant irrigation flow rate of 8 mL/min. The aim of this study was to compare procedural outcomes and safety with conventional radiofrequency ablation. An observational study was conducted with patients who underwent first time PVI ablation between August 2020 and January 2022. The cohort was divided into: (1) vHPSD ablation; (2) High-power short duration (HPSD) ablation; (3) THERMOCOOL SMARTTOUCH™ SF (STSF). The vHPSD ablation group was prospectively recruited while the HPSD and STSF group were retrospectively collected. Primary outcomes were procedural success, PVI duration, ablation duration and incidence of perioperative adverse events. Secondary outcomes were intraprocedural morphine and midazolam requirement. A total of 175 patients were included in the study with 100, 30 and 45 patients in the vHPSD, HPSD and STSF group, respectively. PVI was successfully attained in all vHPSD patients. vHPSD demonstrated significantly reduced time required for PVI and total energy application in comparison to the HPSD and STSF groups (67.7 29.7 vs. 92.9 25.7 vs. 93.6 29.1 min, p 0.0001; 9.87 4.16 vs. 33.9 7.49 vs. 36.0 10.5 min, p 0.0001, respectively). Intravenous morphine and midazolam requirement was lower in the vHPSD group compared to the HPSD and STSF groups (10.2 3.43 vs. 16.1 4.58 vs. 15.3 3.94 mg, p 0.0001; 4.04 3.24 vs. 8.63 5.22 vs. 8.58 4.72 mg, p 0.0001). One cardiac tamponade was observed in both the vHPSD and HPSD groups while the STSF group exhibited an embolic stoke and two pericardial effusions that did not require drainage. In this study, vHPSD demonstrated a comparable safety profile to the other treatment arms. Procedural duration and energy application time was substantially reduced along with sedation requirement notwithstanding the limitations of observational study design, these preliminary findings are promising with respect to periprocedural outcomes and safety of vHPSD however longitudinal outcomes will be essential to assessing the overall efficacy of this novel technology.

Is conventional radiofrequency ablation of the superolateral branch, one of the three genicular nerves targeted as standard, necessary or not? A non-inferiority randomized controlled trial.

Radiofrequency ablation is an effective treatment modality in the symptomatic treatment of knee osteoarthritis. Our aim was to compare the efficacy of radiofrequency ablation of the superomedial and inferomedial genicular nerves (2 branches) with the superolateral, superomedial, and inferomedial genicular nerves (3 branches) and to show whether the 2-branch procedure is inferior to the 3-branch procedure. This study is a prospective, randomized, single-blind clinical study. Eligible participants were randomized into 2 groups: group A, which applied the procedure to the superomedial and inferomedial genicular nerves, and group B, which applied it to the superomedial, superolateral and inferomedial genicular nerves. Pain was evaluated with the numerical rating scale, quality of life with the Short Form-36 (SF-36), and disability with the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index before, and at 1 and 3 months after the procedure. A total of 41 patients were included. There were no differences between the groups except for the SF-36 physical health sub-score at baseline. A significant improvement was seen in the numeric rating scale (NRS) score, SF-36 sub-scores, WOMAC Index total, as well as pain and physical function scores in both groups, though no significant difference was detected between the groups during follow-up. Although we were unable to establish the noninferiority of conventional radiofrequency ablation (CRFA) applied to 2 branches to CRFA applied to 3 branches, in this trial, significant and similar improvement was observed in NRS, WOMAC total, pain, and physical function and SF-36 scores in both groups.

Clinical effectiveness of focused ultrasound combined with plasma radiofrequency ablation technique in the treatment of persistent strain rhinitis.

Examine the effects of focused ultrasound in combination with plasma radiofrequency ablation technology on the physiological stability and postoperative recovery of persistent strain rhinitis. For a control experiment, 90 patients with persistent strain rhinitis were chosen and split into two groups: the control group (CG) and the experimental group (EG). The CG used conventional radiofrequency ablation technology, while the EG used focused ultrasound technology combined with radiofrequency ablation technology to treat persistent strain rhinitis. Between the EG and the CG, compare and contrast the recovery of nasal symptoms, nasal signs, postoperative discomfort, and postoperative respiratory status. One quarter after surgery, there was a substantial difference in physical sign ratings between the EG and the CG, and a particularly significant difference was seen after six months of treatment. One year following surgery, there was a statistical difference between the EG and the CG in the comparison of effective rates at various intervals, with a P value of .013. At 6 months following surgery, the MTT times in the EG and CG for the comparison of nasal function were 12.63 2.65 and 17.68 2.84, respectively, with statistically significant differences. The difference between the EG and the CG in the MTR comparison is statistically significant. In the comparison of NNO values between the EG and the CG after different treatment times. The nitric oxide value of the EG patients decreased over time, with statistical significance one month after surgery and one year after surgery. It is evident from the comparison of various symptom efficacy rates that the EG has a higher treatment effectiveness rate than the CG, and the total treatment effect difference following surgery has statistical significance. Indicators for PONV, PA, directional ability, respiratory recovery, and olfactory recovery performed better in the EG than in the CG, and the differences were statistically significant. Focused ultrasound and plasma radiofrequency ablation technology have a good therapeutic impact in the treatment of persistent strain rhinitis and can significantly reduce MTT. This technology can effectively improve symptoms such as nasal congestion, nasal flow, and headache in patients, and the therapeutic effect is long-lasting. The hospitalization time after treatment is significantly shortened.

Multiphoton simultaneous multislice imaging.

To develop multiphoton excitation techniques for simultaneous multislice (SMS) imaging and evaluate their performance and specific absorption rate (SAR) benefit. To improve multiphoton SMS reconstruction quality with a novel CAIPIRINHA (controlled aliasing in parallel imaging results in higher acceleration) design. When a conventional single-slice RF field is applied together with an oscillating gradient field, the two can combine to generate multiphoton excitation at multiple discrete spatial locations. Because the conventional RF is reused at multiple spatial locations, multiphoton excitation offers reduced SAR for SMS applications. CAIPIRINHA shifts are often used to improve parallel-imaging acceleration. Interestingly, CAIPIRINHA-type shifts can be obtained for multiphoton SMS by updating the oscillating gradient phase at every phase encode. In this work, both a gradient-echo and a spin-echo sequence with multiphoton CAIPIRINHA-SMS excitation pulses are implemented for in vivo human imaging at 3 T. For three slices, multiphoton SMS provides a 51% reduction in SAR compared with conventional superposition SMS, whereas for five slices, SAR is reduced by 66%. Multiphoton SMS outperforms PINS (power independent of number of slices) and MultiPINS in terms of SAR reduction especially when the pulse duration is short, slices are thin, and/or the slice spacing is large. A custom CAIPIRINHA phase-encoding design for multiphoton SMS significantly improves reconstruction quality. Multiphoton SMS excitation can be obtained by combining conventional single-slice RF pulses with an oscillating gradient and offers significant SAR benefits compared with conventional superposition SMS. A novel CAIPIRINHA design allows higher multiband factors for multiphoton SMS imaging.

Head-to-head comparison of pulsed field ablation, very high power-short duration, cryoballoon and conventional radiofrequency ablation by LGE-MRI-based ablation lesion assessment

Abstract Background Novel concepts for pulmonary vein isolation (PVI) like pulsed field ablation (PFA) or high power-short duration ablation (HPSD) promise favourable profiles of safety and efficacy. However, clinical comparisons of ablation lesion quality are lacking. Purpose To systematically investigate lesion characteristics of novel ablation concepts, we performed a prospective head-to-head comparison between PFA, HPSD, conventional RF and latest generation cryoballoon ablation using late gadolinium enhancement (LGE)-MRI-based ablation lesion assessment. Methods This study included patients that underwent first-time PVI-only atrial fibrillation ablation - either by ablation index-guided RF ablation, cryoballoon ablation (Arctic Front Advance Pro), HPSD ablation (QDOT micro catheter, QMODE+, 90W, 4s) or PFA (Farapulse PFA system). All patients received an LGE-MRI 3 months post-ablation. LGE was quantified based on the signal intensity ratio of each voxel relative to the blood pool, applying a previously validated threshold of &amp;gt;1.2 to define LGE indicative of ablation-induced scarring using a dedicated software. LGE discontinuations of &amp;gt;3 mm were considered as gaps, and complete lesions were defined as LGE covering &amp;gt;90% of the peri-antral circumference of ipsilateral pulmonary vein (PV) pairs. Results Post-ablation LGE-MRIs from 120 patients were analysed (40 RF, 40 cryoballoon, 20 PFA, 20 HPSD). The proportion of complete PV-encircling LGE lesions was significantly higher with conventional RF than with cryoballoon ablation (50% vs. 34%; p=0.023). Importantly, HPSD ablation resulted in even more complete lesions than conventional RF (68%, p=0.004), whereas the proportion of complete LGE lesions was lowest with PFA (21%). Accordingly, the total number of gaps was lower with HPSD ablation (1.9 gaps/patient) compared to the other ablation concepts (conventional RF 2.7, cryoballoon 3.2, PFA 3.4 gaps/patient; p=0.034). As expected, large-area ablation with the cryoballoon (13.8 mm) and PFA (12.8 mm) single-shot devices resulted in the widest lesions. Of note, HPSD lesions were significantly wider than conventional RF lesions (11.1 mm vs. 8.9 mm; p=0.004). Conclusions HPSD ablation resulted in the most continuous lesions, translating in the lowest number of gaps. Of note, HPSD lesions were also significantly wider than conventional RF lesions, thus corroborating the concept of a shallower HPSD lesion geometry from experimental studies. Interestingly, conventional RF showed a higher proportion of complete PV-encircling lesions than cryoballoon ablation. While PFA lesions cover relatively large areas, comparable to cryoballoon ablation, lesions are more inhomogeneous. However, it remains to be determined, to what extent LGE discontinuities in PFA lesions indicate ineffective ablation or only reflect a different kind of remodeling compared to thermal ablation, which may be less detectable by LGE-MRI.

Bipolar catheter ablation of left ventricular summit PVC

Abstract Background Premature ventricular contractions (PVC) arising from the left ventricular summit are a challenging arrhythmia to manage, often refractory to conventional radiofrequency ablation. This study aimed to investigate the effectiveness of bipolar ablation as a therapeutic option for PVCs originating from this anatomically complex region. Methods We conducted a retrospective analysis of a prospective ablation registry to identify patients with recurrent, symptomatic PVCs originating from the left ventricular (LV) summit who underwent bipolar ablation. Bipolar ablation involved the use of two ablation catheters, delivering radiofrequency energy from opposite sides of the summit. The catheters were connected by a dedicated adapter, allowing to connect one ablation catheter in position of a return electrode. Procedural success was defined as the elimination of PVCs during the procedure and freedom from PVCs on follow-up monitoring. Results were compared to a similar patient group who had received unipolar ablation of summit-PVCs. Results A total of 12 pts received bipolar ablation between July 2022 and October 2023. Three pts underwent ablation for VT and were excluded. A total of 9 pts (mean age 57±18 years, n=7 [78%] male, BMI 28±5kg/m2) were included in the analysis. All but one had a history of a previous unsuccessful ablation attempt (median 1 [1-2]). In a group of 33 patients undergoing unipolar ablation 8 (32%) had received ≥ 1 previous ablation and were included in the analysis. Baseline parameters did not differ between groups. The acute procedural success rate for bipolar ablation was 89% in bipolar pts and 75% in unipolar pts, with a mean procedural time of 173±33 min, a mean fluoroscopy time of 14±9 min (158±55 min [p=0.478] and 14±12 min [p=0.995] for unipolar pts). Bipolar ablation was performed between the LVOT and RVOT in 6, and between LVOT and the distal CS in 6 pts with 25-35 W. No major complications were detected in bipolar pts while one non-fatal tamponade occurred in the unipolar pts group. Follow-up data at 97 [93-269] days revealed a sustained reduction in PVC burden in bipolar pts (from 18±13% to 7±9%; p=0.026) while unipolar ablation did not show a significant burden reduction (15±6% to 11±10%; p=0.382). The success rate of a relative burden reduction &amp;gt;50% did not differ significantly between the groups (bipolar: 6 pts [67%] 3 pts [38%]; p=0.347). Conclusion Bipolar ablation offers an effective and safe therapeutic approach for PVCs originating from the LV summit. It significantly reduced PVC burden in this analysis. The data suggest that a repeat procedure after a failed summit PVC ablation should only be performed if bipolar ablation is available during the second procedure. Larger studies are warranted to confirm efficacy and safety of this ablation method.