Bipolar Radiofrequency Research Articles

Sinus node sparing novel hybrid approach for treatment of inappropriate sinus tachycardia/postural sinus tachycardia: multicenter experience

BackgroundThe ideal treatment of inappropriate sinus tachycardia (IST) and postural orthostatic tachycardia syndrome (POTS) still needs to be defined. Medical treatments yield suboptimal results. Endocardial catheter ablation of the sinus node (SN) may risk phrenic nerve damage and open-heart surgery may be accompanied by unjustified invasive risks.MethodsWe describe our first multicenter experience of 255 consecutive patients (235 females, 25.94 ± 3.84 years) having undergone a novel SN sparing hybrid thoracoscopic ablation for drug-resistant IST (n = 204, 80%) or POTS (n = 51, 20%). As previously described, the SN was identified with 3D mapping. Surgery was performed through three 5-mm ports from the right side. A minimally invasive approach with a bipolar radiofrequency clamp was used to ablate targeted areas while sparing the SN region. The targeted areas included isolation of the superior and the inferior caval veins, and a crista terminalis line was made. All lines were interconnected.ResultsNormal sinus rhythm (SR) was restored in all patients at the end of the procedure. All patients discontinued medication during the follow-up. After a blanking period of 6 months, all patients presented stable SR. At a mean of 4.07 ± 1.8 years, normal SN reduction and chronotropic response to exercise were present. In the 51 patients initially diagnosed with POTS, no syncope occurred. During follow-up, pericarditis was the most common complication (121 patients: 47%), with complete resolution in all cases. Pneumothorax was observed in 5 patients (1.9%), only 3 (1.1%) required surgical drainage. Five patients (1.9%) required a dual-chamber pacemaker due to sinus arrest > 5 s.ConclusionsPreliminary results of this multicenter experience with a novel SN sparing hybrid ablation of IST/POTS, using surgical thoracoscopic video-assisted epicardial ablation combined with simultaneous endocardial 3D mapping may prove to be an efficient and safe therapeutic option in patients with symptomatic drug-resistant IST and POTS. Importantly, in our study, all patients had a complete resolution of the symptoms and restored normal SN activity.

In vivo preliminary test of a new biparietal bidirectional bipolar radiofrequency magnetic coupling system

BackgroundTo test in vivo a new design prototype for radio frequency (RF) ablation.MethodsA prototype based on a concept of endo‐epicardial biparietal bipolar RF ablation with the atrial tissue interposed and consisting of two specular endocardial‐epicardial catheters was tested in four pigs (80±5 kg). The endocardial catheter was introduced into the left atrium through the left atrial appendage on the beating heart. The epicardial counterpart was placed manually on the atrial epicardial surface. The coupling of the two catheters was achieved using a neodymium magnet around the gold plate electrode, and RF was applied to the interposed tissue. The hearts were excised, and the lesions were examined using morphometric evaluation.ResultsThe RF application resulted in transmural lesions in all of the four animals tested. In these animals the maximum endocardial width (Wendo) was 6.34 ± 0.25, 6.54 ± 0.33, 6.36 ± 0.57, and 6.49 ± 0.96 mm. The pericardial width (Wepi) was similar: 6.37 ± 0.47, 6.58 ± 0.32, 6.35 ± 0.56 and 6.53 ± 0.94 mm. The lesion area was 924.78, 949.25, 944.25, and 926.05 mm2, and the lesion volume was 92.47, 94.92, 94.42, and 92.60 mm3, respectively.ConclusionsThe idea of an endocardial‐epicardial bidirectional biparietal bipolar radiofrequency tool such that the atrial tissue is fully interposed between the two RF poles might be promising for future clinical applications. Further research is warranted.

The treatment of chronic low back pain using annuloplasty with percutaneous endoscopic discectomy

Abstract Introduction: Percutaneous endoscopic discectomy (PED) is often used to treat patients with chronic discogenic low back pain (LBP) (DLBP). In this technique, after selective discectomy of the degenerated disc, the posterior annulus fibrosus and tear site are modulated by thermal annuloplasty (TA) using a bipolar radiofrequency coagulator (PED/TA). PED/TA has been shown to be effective for treating DLBP. Patient Concerns: The patient was a 40-year-old man who visited our hospital with complaints of chronic LBP (CLBP) and buttock pain, left-sided sciatica, and sensory disturbance affecting his left thigh. Diagnoses and interventions: He was diagnosed as having discogenic LBP with a high intensity zone in the L4–5 disc, so discography was performed combined with steroid and lidocaine injection at the affected site. He recovered from LBP with 80% effective rate. He again reported concordant LBP with leg pain and numbness, which was treated effectively by intradiscal injection. However, the pain gradually recurred, so we decided to perform PED/TA. Outcomes: After PED, the high intensity zone site was ablated with a coagulator. Following surgery, the patient's severe LBP in the seated position resolved, his leg pain and sensory disturbance improved, and has experienced no difficulties in carrying out activities of daily living. Conclusions: This case suggests that PED/TA is potentially advantageous for treating DLBP, CLBP and severe sitting intolerance. Also, PED/TA may allow lumbar interbody fusion to be avoided in patients with CLBP and severe sitting intolerance.

B-PO03-133 BIPOLAR RADIOFREQUENCY ABLATION USING ANGIOPLASTY GUIDEWIRES

Intramural ventricular arrhythmias represent a challenge for catheter ablation. Angioplasty guidewires can be used to map septal coronary veins that are inaccessible to standard ablation catheters and eventually could have a role in the ablation of septal arrhythmogenic substrate. To evaluate the feasibility of bipolar radiofrequency (RF) ablation using an angioplasty guidewire as the return electrode. An ex-vivo model consisting of a piece of porcine myocardium submersed in a normal saline bath was used. RF energy was applied between an irrigated ablation catheter (Tacticath, Abbott) positioned on the endocardial surface and a partially coated angioplasty guidewire (Luge, Boston Scientific) placed on the adjacent epicardial surface, connected to the indifferent port of the RF generator. RF applications using powers between 20-50W resulted in effective lesion formation on both sides of the ventricular myocardium, but powers ≥30W were associated with a higher incidence of steam pops. When a power of 20W was applied (25 lesions) the baseline impedance was 180±22 Ω, with impedance drop of 44±17 Ω and no steam pops. The lesion volume was 237±182 mm3 and transmural lesions were observed in tissues measuring 10-15 mm thickness (Figure: In the left panel the orientation of the electrodes is oblique, resulting in 2 separate lesions; in the right panel both electrodes are directly opposed, resulting in a transmural lesion core). Bipolar RF ablation between an ablation catheter and an angioplasty guidewire is feasible and may result in transmural lesions. Further studies are required to confirm the efficacy and safety of this ablation approach.

Transvaginal radiofrequency energy for the treatment of urinary stress incontinence: A comparison of monopolar and bipolar technologies in both pre‐ and post‐menopausal patients

A study to compare the effect of two different radio frequency energy models (mono polar and bipolar) for the treatment of urinary stress incontinence. Retrospective chart review, which was conducted at 2 sites, 69 patients received treatment with a bipolar radiofrequency device. Out of those 69 patients, 13 patients received bipolar in conjugation with CO2 laser treatment, while 32 patients received monopolar frequency. The study protocol normally consists of three sessions of treatment. Each session was four weeks apart with a whole 6-month duration follow-up. Results were evaluated by urogenital distress inventory (UDI)-6 questionnaire before and after treatment. The bipolar group improved UDI-6 scores across time more so than did the monopolar group with some evidence suggesting that the bipolar radiofrequency treatment was more effective compared to the monopolar radiofrequency. Three months after treatment, the bipolar group UDI-6 values were lower than those of the monopolar group. Six months after treatment, the UDI-6 scores increased in both groups, suggesting decrease efficacy with time however, the bipolar group's UDI-6 scores were consistently lower than the monopolar group's scores. This study shows benefit of both monopolar and bipolar radiofrequency device in patients with stress urinary incontinence and mixed UI, with bipolar RF more efficacious than monopolar RF. More randomized prospective studies are needed to confirm these findings.

The Role of Bipolar Radiofrequency (Bprf) as a Mechanism of Bio-Stimulation for the Treatment of Vulvo-Vaginal Laxity: A Novel Approach

The Role of Bipolar Radiofrequency (Bprf) as a Mechanism of Bio-Stimulation for the Treatment of Vulvo-Vaginal Laxity: A Novel Approach

A Review of Hypertrophic Scar and Keloid Treatment and Prevention in the Pediatric Population: Where Are We Now?

Significance: This body of work gives a concise and comprehensive overview for the clinician and scientist on the latest treatment modalities for hypertrophic scars (HTS) and keloids in the pediatric population, as well as the most promising methods of prevention currently being investigated. This review will serve as a guide to the clinician for treatment selection and as an efficient tool for the scientist to achieve a comprehensive overview of the scientific literature to guide their future experiments aimed at pathologic scar prevention. Recent Advances: Current studies in the literature suggest carbon dioxide (CO2) laser and E-light (bipolar radiofrequency, intense pulsed light, and cooling) are two of the most effective treatment modalities for HTS, while surgical excision+CO2 laser+triamcinolone injection was one of the most successful treatments for keloids. In animal models, drug impregnated electrospun nanofiber dressings offer encouraging results for HTS prevention, while Kelulut honey showed promising results for keloid prevention. Critical Issues: Treatment outcome reproducibility is hindered by small cohorts of patients, inadequate-follow up, and variability in assessment tools. Prevention studies show multiple ways of achieving the same result, yet fall short of complete prevention. Furthermore, some studies that have purported full prevention have not been validated. Future Directions: To establish a standard of care, large clinical trials of the most successful modalities in small cohorts are needed. The key for prevention will be validation in animal models of the most successful methods, followed by translational and clinical studies.

Local anesthesia for percutaneous US/CT-guided bipolar radiofrequency ablation of small renal masses: A safe and feasible alternative

PurposeThis study is to evaluate the safety and feasibility of local anesthesia (LA) for percutaneous ultrasound/computed tomography (US/CT)-guided bipolar radiofrequency ablation (RFA) for small renal masses (SRMs) by comparing the LA with general anesthesia. Materials and MethodsA retrospective review was carried out between January 2018 to June 2020, 102 patients with SRMs were treated with US/CT-guided bipolar RFA. General anesthesia (GA) was performed in 42 and LA was performed in 60 patients. Demographics, tumor characteristics, peri-procedural data, pathologic and follow-up outcomes were analyzed. The factors associated with pain were also identified. ResultsThere was no significant difference in demographics and tumor characteristics between the LA and GA group. A statistically significant difference was observed in terms of procedural time (P = 0.010) and hospital stays (P < 0.001). The maximum perceived pain in LA group comprised 60.0% (36 of 60) mild, 40.0% (24 of 60) moderate. The anxiety in LA group comprised 65.0% (39 of 60) mild, 33.3% (20 of 60) moderate, 1.7% (1 of 60) severe. On multivariate analysis, tumor diameter was a significant predictor for pain in RFA procedure (OR 1.560, 95% CI 1.233–1.974, P < 0.001). All patients were followed up for a median (range) of 12 (2–24) months. Local recurrence occurred in 8.3% (5 of 60) of the LA group and in 7.1% (3 of 42) in GA group (P = 1.000). ConclusionPercutaneous bipolar RFA of SRMs using CT and ultrasound guidance under LA can be an effective and tolerable method for patients who are unfit for surgery and provide satisfactory oncologic control.

THE EFFECT OF BIPOLAR RADIOFREQUENCY ABLATION (NOVASURE ENDOMETRIAL ABLATION SYSTEM) ON ENDOMETRIAL THICKNESS AND BLEEDING IN PATIENTS WITH PREMENOPAUSAL BLEEDING

Background: Ablation of the endometrial lining of the uterus as an alternative to hysterectomy was found to be a less invasive and aggressive method. A large number of clinical trials, as well as retrospective analysis of clinical and financial data, has shown that endometrial ablation allows for a lower morbidity and mortality rate and significantly lower procedure costs. Worldwide, endometrial ablation is increasingly being adopted by the gynecological community. Objective: To study the effect of bipolar radiofrequency ablation system on endometrial thickness and bleeding in patients with premenopausal bleeding. Patients and Methods: This was a prospective comparative randomized study including 30 women with premenopausal bleeding not responding to medical treatment performed at Al-Azhar University hospitals and Gamal Abdel Nasser Hospital during the period from April 2016 to October 2018. Results: The majority of the patients improved (83.3%), 19 of them have complete recovery (63.3%), while 6 cases (20.0%) have minor bleeding, 4 cases (13.3%) have bleeding less before treatment, while only one case has no change. Conclusion: Bipolar radiofrequency ablation performed under local anaesthetic in the postmenstrual phase is an effective and efficient method of treating the majority of women who wish conservative surgical treatment for heavy menstrual loss.

Catheter, surgical, or hybrid procedure: what future for atrial fibrillation ablation?

BackgroundThe debate on the best treatment strategy for atrial fibrillation (AF) has expanded following the introduction of the so-called “hybrid procedure” that combines minimally invasive epicardial ablation with endocardial catheter ablation. However, the advantage of the hybrid approach over conventional epicardial ablation remains to be established.MethodsFrom June 2008 to December 2020, 609 surgical AF ablation procedures through a right minithoracotomy were performed at our institution. From 2008 to 2011, a unipolar radiofrequency (RF) device was used, whereas from 2011 to 2020 a bipolar RF device was used. In addition, between September 2016 and April 2017, 60 patients underwent endocardial completion of epicardial linear ablation. In 30 of these latter patients, surgical isolation of the Bachmann’s bundle (BB) was also performed. Starting from 2021, surviving patients at follow-up were asked to undergo electrocardiographic evaluation and left ventricular function assessment and to complete a questionnaire addressing quality of life and predisposing factors for recurrent AF.ResultsThe ablation procedure was completed in all patients. Upon discharge, 30 (4.9%) patients showed recurrence of AF, whereas the remaining patients (95.1%) were in sinus rhythm. All patients in whom a hybrid approach was used either with or without BB ablation were discharged in sinus rhythm. After a mean follow-up of 74 months, 122 (20%) patients developed recurrent AF, including 19.9% in whom a unipolar RF device was used, 21% in whom a bipolar RF device was used, 23% who had undergone a hybrid procedure without BB ablation and 3.3% who had undergone a hybrid procedure with BB ablation. On multivariate analysis, reduced left ventricular ejection fraction, worsening of European Heart Rhythm Association symptom class, and cognitive impairment or depression during follow-up were found to be significantly associated with AF recurrence.ConclusionsSurgical AF ablation through a right minithoracotomy is safe and may allow the creation of additional linear lesions, particularly in the BB. The placement of adjunctive linear lesions in the setting of a hybrid procedure can be more effective in reducing the risk for AF recurrence than isolated surgical ablation or hybrid ablation without the addition of further linear lesions, with no incremental risk to the patient.

The combination of endoluminal radiofrequency ablation and metal stent implantation for the treatment of malignant biliary stenosis – Randomized study

PurposeTo analyse whether endobiliary radiofrequency ablation prior metal stent insertion in malignant biliary stenosis show improved survival or stent patency. Methods76 patients with histologically proven malignant biliary stenosis have been enrolled in a prospective, randomized study. In control arm, 40 patients underwent self-expandable metal stent insertion. In experimental arm, the endoluminal ablation with a bipolar radiofrequency catheter was performed immediately before stent insertion. A subgroup analysis of cholangiocarcinoma was performed (22 vs 21 patients). The objective of the study was to determine the rate of complications, duration of the stent patency and the survival of patients (Kaplan-Meier analysis). ResultsNo major complications related to the stent insertion and the endoluminal ablation were found. The mean primary stent patency was 5.2 (95% CI 0.7–12.8) vs 4.8 months (95% CI 0.8–18.2) months (p = 0.79) in control and experimental group, respectively, in the subgroup analysis with cholangiocarcinoma 4.5 (95% CI 0.8–10.3) and 9.6 (95% CI 5.2–11.2) months (p = 0.029). The median survival since the insertion of the stent was 6.8 (95 %CI 3.0–10.6) vs 5.2 (95 %CI 2.4–7.9) months (p = 0.495) and since the initial drainage 9.8 (95 %CI 6.9–12.7) vs 9.1 (95 %CI 5.4–12.7) months (p = 0.720) in the control and experimental arm. ConclusionEndobiliary radiofrequency ablation prior metal stent insertion showed increased patency rate only in patients with cholangiocarcinoma, on the other hand, no improvement in survival was demonstrated in this randomized clinical study.

A Computational and Experimental Study to Compare the Effectiveness of Bipolar Mode With Phase-Shift Angle Mode in Radiofrequency Fat Dissolution on Subcutaneous Tissue.

Radiofrequency (RF) energy exposure refers to a popular non-invasive method employed to generate heat in cutaneous and subcutaneous tissues. RF thermal stimulation of adipose tissue has been considered to cause adipocyte metabolism and enzymatic degradation of triglycerides into free fatty acids and glycerol. Bipolar mode (BM) has achieved extensive applications in clinical studies on RF fat dissolution, whereas BM has a less penetration depth than monopolar, result in a higher RF voltage that may be required to increase power to the deeper fat layer of the subcutaneous tissue, and improper power control may easily cause the skin layer to be thermally damaged. To tackle down the mentioned defect, a novel phase-shift angle mode (PM) was proposed in this study based on double-channel bipolar RF. By employing the finite element method (FEM) and performing the ex vivoexperiment, the effectiveness of BM was compared with that of PM in RF fat dissolution on subcutaneous tissue. In addition, this study attempted to develop reasonable phase-shift angles capable of achieving fat dissolution effects, while the RF energy of which would not cause the skin layer to be thermally damaged. Two electrode spacings (1 and 2 cm) were applied in BM (BM-1 cm and BM-2 cm, respectively), and six phase-shift angles (i.e., 30°, 60°, 90°, 120°, 150°, and 180°) were set in PM (i.e., PM-30°, PM-60°, PM-90°, PM-120°, PM-150°, and PM-180°). In addition, COMSOL was adopted to conduct a finite element analysis for achieving thermoelectric coupling. Ex vivo experiments were performed with a self-developed double-channel bipolar RF device, through which up to two adjustable phase-shift angle sinusoidal voltages could be generated. Such a device was isolated with a transformer and then connected to four electrodes with a 5 mm diameter contacting the ex vivo porcine abdominal tissue. Under the RF voltage amplitude of 30 V, and after 1800 seconds of RF heating, no thermally damaged area was formed in the tissue in BM-1 cm and BM-2 cm; in PM-30°, PM-60°, and PM-90°, thermally damaged areas were formed in the fat layer, while the skin layer was not located in the thermally damaged area.Moreover, the temperature in the thermally damaged area attributed to the mentioned three conditions may satisfy the requirement of fat dissolution temperature. Under the identical RF voltage and heating time, PM is easier to cause the fat layer of the subcutaneous tissue to be thermally damaged as compared with BM. Accordingly, PM may be enabled to achieve the fat dissolution effect under a relatively low RF voltage as opposed to BM, thus avoiding the possibility of thermal damage of the skin layer attributed to the use of higher RF voltage. In PM, different phase-shift angle significantly affects the electrical and thermal properties of RF energy applied on subcutaneous tissue; the phase-shift angle of RF voltage is likely to be regulated for fat dissolution effect, while the RF energy of which will not cause the skin layer to be thermally damaged.© 2021 Wiley Periodicals LLC.

Biophysical evaluation of clinical bipolar radiofrequency ablation approaches in a porcine ex-vivo model

Abstract Funding Acknowledgements Type of funding sources: None. Background Bipolar radiofrequency catheter ablation (BA) is an important therapeutic option for therapy refractory ventricular arrhythmias. BA approaches may frequently include titration of energy from lower to higher levels and target epicardial sites with overlying fat tissue. However, the actual effect on lesion formation has not been evaluated. Purpose Investigating lesion modalities during BA (a) using low-to-high energy titration, (b) conducting prior sequential unipolar ablation additional to BA and (c) in epicardial fat tissue. Methods An ex-vivo model consisting of freshly explanted swine hearts positioned in a circulating temperature-controlled saline bath was established. An irrigated active and ground ablation catheter with a 3.5mm tip connected to a novel single generator capable of performing BA were positioned on both sides of the left ventricular/ventricular septal myocardium orthogonal to respective swine tissue. Radiofrequency energy was applied with a fixed force of 10 g for 60 s using different approaches: (1) Titration group, BA of 30 W following BA of 50W; (2) sequential group, ablating unipolar from both catheters using 30 W; (3) epicardial fat group (fat thickness &amp;gt;1 cm) with BA of 50W; (4) sequential + BA group, applying unipolar energy of 30 W first on both catheters with consecutive BA of 50W; (5) control group, with BA of 30, 40 or 50 W only. Dimensions of set lesion as well as bipolar generator impedance during ablation were assessed. Results A total of 65 ablation lesions were analyzed. The mean tissue thickness was 18 ± 3 mm (range 11-23 mm), with a mean fat thickness of 3.5 ± 1.1 mm in the epicardial fat group. Overall, transmurality was observed in 17 lesions (26%) with the highest rates in the titration and sequential + BA group (75 / 100%), while no difference to the control group applying 50 W was detected (Kruskal-Wallis test, p = 0.30/0.19) and no lesion displaying transmurality in the epicardial fat group (p &amp;lt; 0.001). The maximum impedance drop during ablation was highest in the control group applying 50 W and lowest in the epicardial fat group (51 ± 24 vs 23 ± 12 Ω, p = 0.02). The lesion volume did not differ between titration and control group applying 50 W (455 ± 230 vs 426 ± 268 mm3, p &amp;gt; 0.99), whereas being significantly larger than in the epicardial fat group [median 59 (interquartile range 41-92 mm3), p = 0.02/0.01]. The sequential + BA group showed significantly increased lesion volume compared with both titration and control group [1401 (1093-1728) mm3, p = 0.004, Figure]. Eleven steam pops (17%) were registered with similar distribution between groups (p = 0.24). Conclusion Lesion dimensions were similar between the BA titration approach and BA solely applying 50 W. Prior sequential unipolar ablation may significantly increase ablation lesion volumes during BA. The effect of BA at sites of significant epicardial fat tissue &amp;gt;1 cm may be severely limited, which should be considered during procedure planning. Abstract Figure. Lesion dimensions in BA approaches

Review of Radiofrequency Ablation in Tonsillectomy.

The most common disease involving the tonsils among children and adults is chronic tonsillitis. There are different surgical techniques described in literature for the treatment of diseases involving the tonsils. Of these, the most routinely performed and the traditional method is conventional dissection tonsillectomy. The main disadvantage of this method is bleeding and postoperative pain. Radiofrequency ablation is found to overcome this limitation due to its mechanism of action. Both monopolar and bipolar radiofrequency ablation can be used in the surgical management. The effectiveness of monopolar radiofrequency has been proved in different fields of medicine. Hence new studies can be directed in comparing monopolar radiofrequency ablation with other techniques of tonsillectomy.

Complex treatment of patients with hormone-dependent atrophic scars

BACKGROUND: There are a large number of different methods of treating striae, starting with local therapy with various oils, ending with hardware techniques, but standardized treatment protocols have not yet been developed, which forces us to look for new promising combined treatment regimens&#x0D; AIMS: To study the effectiveness of therapeutic complexes in patients with atrophic hormone-dependent scars.&#x0D; MATERIAL AND METHODS: 145 patients with hormone-dependent scars with different AP phenotypes were followed up. In groups 1A and 1B, phototherapy was performed using broadband incoherent light-IPL therapy. In groups 2A and 2B, exposure was performed using bipolar fractional radiofrequency therapy. In groups 3A and 3B, the patient underwent a mesoroller microneedling procedure. PRP therapy was performed in groups 1B, 2B, and 3B. A visual analog scale (VAS) was used to evaluate the effectiveness.&#x0D; RESULTS: Comparing the data obtained, it should be noted that, regardless of the age of the scar (red, white), the developed complex methods of therapy showed greater effectiveness than monotherapy with pulsed broadband light, RF microneedles or microneedling.&#x0D; CONCLUSION: The combination of RF-therapy and PRP-therapy showed the greatest effectiveness against all clinical symptoms of AR, IPL-therapy with plasma with cells and plasma-with-cells microneedling showed a comparable high efficiency in different periods of AR existence.

Efficacy of fractional laser, radiofrequency and IPL rejuvenation of periorbital region

The purpose of this study was to assess skin elasticity, the reduction in the number and the depth of wrinkles and changes in the other skin defects (bags under the eyes, dark circles under the eyes, skin hyperpigmentation in the ageing eye area following the use of non-ablative fractional laser, bipolar radiofrequency and intense pulsed light). Moreover, the study was also comparison which device brought better results than the others. This study included 71 patients (66 women, 5 men), aged 33–63 years (the average age was 45.81 years) with skin phototypes II and III. Twenty-four patients received five treatment sessions with a 1410-nm non-ablative fractional laser in 2-week intervals, 23 patients received five treatment sessions with a bipolar radiofrequency in 1-week intervals and 24 patients received five treatment sessions with an intense pulsed light in 2-week intervals. The treatment was applied on the skin in the eye area. The Cutometer (Courage + Khazaka electronic) reference test was used as an objective method for the assessment of skin elasticity. A questionnaire was used to compare baseline state with changes that occurred after the series of treatment sessions. The results of cutometric measurements of R2, R6 and R7 parameters and the results of questionnaires indicated that non-ablative fractional laser therapy, bipolar radiofrequency and intense pulsed light improved skin elasticity. Of the three treatments, the most significant percentage improvement in the R6 parameter was demonstrated by non-ablative fractional laser therapy which gave better final results than the other methods (p < 0.0001). No other statistically significant relationships were found between RF and IPL. In the (subjective) opinion of study participants (questionnaire), all used methods resulted in the reduction of the amount and the depth of wrinkles. However, they did not observe significant impact of individual treatment method on the signs of skin ageing, including discolorations within eye area, bags (fatty hernia), dark circles (vascular/pigmentary) and oedema (predisposition to water retention). Non-ablative fractional laser therapy, bipolar radiofrequency and intense pulsed light improved skin elasticity and the reduction of wrinkles. The most significant improvement of elasticity was demonstrated by laser therapy. It seems necessary to expand the group with the effect of individual treatments against bags and dark circles under the eyes.

Comparisons between impedance-based and time-based switching bipolar radiofrequency ablation for the treatment of liver cancer

Switching bipolar radiofrequency ablation (bRFA) is a cancer treatment technique that activates multiple pairs of electrodes alternately based on a predefined criterion. Various criteria can be used to trigger the switch, such as time (ablation duration) and tissue impedance. In a recent study on time-based switching bRFA, it was determined that a shorter switch interval could produce better treatment outcome than when a longer switch interval was used, which reduces tissue charring and roll-off induced cooling. In this study, it was hypothesized that a more efficacious bRFA treatment can be attained by employing impedance-based switching. This is because ablation per pair can be maximized since there will be no interruption to RF energy delivery until roll-off occurs. This was investigated using a two-compartment 3D computational model. Results showed that impedance-based switching bRFA outperformed time-based switching when the switch interval of the latter is 100 s or higher. When compared to the time-based switching with switch interval of 50 s, the impedance-based model is inferior. It remains to be investigated whether the impedance-based protocol is better than the time-based protocol for a switch interval of 50 s due to the inverse relationship between ablation and treatment efficacies. It was suggested that the choice of impedance-based or time-based switching could ultimately be patient-dependent.

Commentary on: Bipolar Fractional Radiofrequency Treatment of Suprapatellar Skin Assessment Using Noninvasive Devices and Microbiopsy

Commentary on: Bipolar Fractional Radiofrequency Treatment of Suprapatellar Skin Assessment Using Noninvasive Devices and Microbiopsy

Bipolar Fractional Radiofrequency Treatment of Suprapatellar Skin Assessment Using Noninvasive Devices and Microbiopsy.

Noninvasive treatments for skin tightening are gaining popularity. However, no studies have assessed bipolar fractional radiofrequency treatment on suprapatellar skin. The purpose of this study was to evaluate the efficacy of bipolar fractional radiofrequency treatment on suprapatellar skin. Twenty patients received 1 bilateral suprapatellar bipolar fractional radiofrequency treatment. They returned 7 days, 3 weeks, 3 months, and 6 months posttreatment. Noninvasive measurements were obtained at each visit, including high-resolution ultrasonography, optical coherence tomography, transepidermal water loss and skin elasticity. Microbiopsies were collected in the treatment area for histologic and gene expression analyses. Three clinicians completed photographic evaluations comparing texture and laxity at baseline vs 6 months posttreatment. Fifteen subjects completed all 6 visits. Both transepidermal water loss and dermal-epidermal junction roughness were increased at 3 weeks and 3 months posttreatment. Both attenuation coefficient and stiffness were increased significantly at 3 and 6 months posttreatment. Blood flow 0.5 mm below the surface and expression of epidermal hyaluronic acid and inflammatory genes IL-1b and IL-6 were significantly higher at 7 days posttreatment compared with pretreatment and 3 months posttreatment. There were no statistically significant changes in collagen- or elastin-related genes and proteins at 7 days or 3 months posttreatment. An improvement in texture and laxity was observed at 6 months posttreatment in 17.7% and 24.4% of photographs, respectively. Radiofrequency treatment by microneedling of suprapatellar skin shows limited effects in decreasing skin laxity and improving skin appearance. At a molecular level, the treatment resulted in lower elastin and hyaluronic acid levels and increased dermal-epidermal junction roughness based on histology and optical coherence tomography imaging.

Intraoperative CARTO Mapping for Atrial Fibrillation Ablation in Patients Undergoing Cardiac Surgery

Objective: Intraoperative CARTO Mapping for Atrial Fibrillation ablation in cardiac surgery. Background: Surgical ablation of Atrial Fibrillation is usually performed without mapping. The study aims to determine if intraoperative CARTO can be useful to guide the ablating procedure. Methods and Findings: Fourteen patients with symptomatic and drug-refractory concomitant AF were operated on in 2003 and 2004. CARTO mapping was performed before and after surgical bipolar radio-frequency ablation. Application of energy was repeated when residual electrical activity was detected at the pulmonary veins-atrial junction. Pacing wires were applied on right and left pulmonary veins distally to the ablation line to confirm the exit block. The mapping protocol was completed in 12 patients. Acute left atrium-pulmonary vein isolation was achieved after single or double energy application in 2/12 (16.6%) and 9/12 (75%) patients, respectively. The mean duration of the mapping and ablation procedure was 67 minutes. At discharge, PV isolation persisted in 10 patients: exit block was confirmed by the absence of pacing through the pulmonary veins electrodes. After a mean follows up of 181 months, no further recurrent AF events were registered in 9/12 (69.2%) patients. Conclusions: CARTO system is useful during open-heart surgery to guide the ablating strategy.