Dose Area Product Research Articles

The impact of clinical audits on patient radiation exposure for device procedures

Abstract Background Clinical audits aim to ensure ideal use of ionizing radiation in clinical practice. Since it became mandatory by Swiss law in 2018, such an audit also took place in our Cardiac Pacing and Electrophysiology Division at the University Heart Center. Purpose To establish local diagnostic reference levels (DRLs) for specific procedures and to examine if patient radiation exposure was reduced after the clinical audit. Methods Retrospective cohort study including patients from October 2018 to October 2020 who underwent device implantation, including pacemakers, implantable cardioverter defibrillators (ICD), cardiac resynchronization therapy (CRT), or lead extraction / device explantation. Main measures to reduce radiation exposure after the audit were lower pulsed fluoroscopy frame rates and dose characteristics at baseline. Patient radiation exposure was evaluated with the dose-area product (DAP), cumulative dose, fluoroscopy time, and the number of cine acquisitions. Secondary endpoints included the effective dose, the acute procedural success rate and 30-day complications. Data were collected from a dose management system and cross-checked for accuracy with the patient information system. The third quartiles were set as local DRLs. Data before and after the clinical audit were compared. Results A total of 541 patients (45.7 % before the audit, 54.3% after the audit) were included. 28.3% had a conventional pacemaker, 22.0% a leadless pacemaker, 21.1% an ICD, and 17.2% a CRT implantation. Lead extraction / device explantation was undergone by 11.5% of patients. The local DRLs (including all procedures before and after the audit) for the DAP were significantly lower as compared to national DRLs (6.2 dGy.cm2 versus 300 dGy.cm2 for conventional pacemakers; 7.6 dGy.cm2 versus 200 dGy.cm2 for ICDs, 203 dGy.cm2 versus 570 dGy.cm2 for CRTs). After the audit, DAP (Figure 1), cumulative dose, effective dose and the number of cine acquisition significantly decreased for conventional pacemakers (p-value ≤ 0.04), whereas no significant differences were observed for the other procedures. The acute procedural success rate (98.4 vs 98.9%) and the 30-day complications (4.0 vs 7.8%) were not significantly different before and after the audit. Conclusions The clinical audit in our institution led to a significant reduction of radiation exposure for patients during pacemaker implantations. Regarding DRLs, local values were far below national DRLs, which suggests that national DRLs need to be updated more regularly. Our study highlights the importance of clinical audits and the need for more research in this field.

Near-zero fluoroscopy technique for cardiac electronic device implantation: long-term outcomes

Abstract Introduction Radiation hazards are a major concern for both patients and staff. We have previously described a near-zero fluoroscopy technique for cardiac electronic device implantation. In this study, we aimed to investigate the long-term safety of this technique and compare outcomes and procedural metrics with a conventional approach in a larger population. Methods Low-dose fluoroscopy technique. Radiation exposure during fluoroscopy is directly proportional to the time the unit is activated. Typically, the pedal switch is depressed for at least a few seconds per imaging sequence in order to visualize "live" movements of either the leads during their positioning or the needle during a fluoroscopy-guided puncture of the subclavian vein. Our technique consists of setting a low frame rate per second (0.5-3.75fps) and momentarily triggering the foot pedal switch only to obtain screenshots of the position of the leads/needle. Use of live electrograms to assist spatial awareness of lead position (e.g. Atrial, Coronary Sinus, Ventricular signals) acts as an adjunct to guidance. Study design We included consecutive patients undergoing permanent pacemaker (PPM) or cardiac defibrillator (ICD) implant at our center from July 2018 to December 2022 using the near-zero fluoroscopy technique. Procedures were performed by three operators (AC, MD, MF). Cumulative radiation dose was measured using dose-area product (DAP). We assessed procedure success and complication rate during long-term follow-up. We compared the procedural metrics and outcomes with a cohort of patients with PPM or ICD implanted in our centre by senior operators, using a traditional fluoroscopic approach. Propensity score was adopted to match baseline characteristics between the study and control group. Results The total population consisted of 412 patients (74.2±13.9 years, 60.9% male). We included 206 who underwent PPM or ICD implantation using the low-dose fluoroscopy technique, and 206 matched-control. A PPM or ICD was successfully implanted in all patients. Fluoroscopy time and DAP were significantly lower in the low-dose fluoroscopy group, mean 2.3±2.0 seconds versus 258.4±252.1 seconds (P<0.001) and 3.4±3.5 µGym2 versus 29.8±55.4 µGym2 (P<0.001), respectively. Mean procedure time was 49.0±20.8 minutes in the low fluoroscopy group and 65.7±26.8 minutes in the control group (P<0.001). Median frame per second setting was 0.5 in the low-dose cohort. After a mean follow-up of 441±470 days, the rate of complications was identical across groups (2.4%, p = 1.0). Conclusion This near-zero dose fluoroscopy technique is effective and safe, enabling a 10x reduction in radiation exposure during device implant. Modification of traditional implant and imaging techniques can provide material reductions in fluoroscopy dose to even below that for a standard PA chest radiograph.

Pulmonary vein isolation using pulsed field ablation versus high-power-short-duration radiofrequency ablation for paroxysmal atrial fibrillation: efficacy, safety, and long-term follow-up

Abstract Background Pulsed field ablation (PFA) is a novel, nonthermal, cardiac tissue selective ablation modality. To date, radio-frequency (RF) guided high-power-short-duration (HPSD) ablation represents the gold standard for pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF). This study investigated the efficacy of PFA-PVI versus HPSD-PVI in terms of single-procedure arrhythmia-free outcome and safety. Methods Consecutive, paroxysmal AF patients who underwent PVI using PFA or HPSD were enrolled. In group PFA, PVI was performed using a 31/35-mm pentaspline PFA catheter. The ablation procedure in group HPSD was performed with HPSD-RF energy (45 watts), using Ablation Index (AI) and the CLOSE protocol. The CLOSE protocol combines AI and ≤6 mm interlesion distance using a 4-mm surround flow catheter. Results A total of 420 patients (group PFA: 211; group HPSD: 209) were included (55% men; age 67 ± 10 years). There was no difference between both groups with regard to age, gender and CHA2DS2-VASc-Score. Complete isolation of all PVs was achieved in 100% of patients. Procedure time was significantly shorter in group PFA (74 ± 41 min vs. 127 ± 34 min; p < 0.001); fluoroscopy time and dose area product were significantly longer in group PFA (18 ± 7 min vs. 4 ± 3 min; p < 0.01 and 555 ± 460 uGym2 vs. 213 ± 273 uGym2; p <0.01). Overall procedural complications were 1,4% in group PFA and 5,2 % in group HPSD (p < 0.01), driven by a higher tamponade rate in group HPSD. During a mean follow-up of 12 months after a single procedure, 170 (81%) patients of group PFA were free of arrhythmia recurrence versus 160 (76%) patients in group HPSD (p = 0.798) (Figure 1). Conclusions PVI using PFA compared to PVI using HPSD shows a similar acute efficacy but a significantly reduced complication rate and a shorter procedure time. One-year clinical success rates are favorable, but not different between groups.Figure 1

Radiofrequency balloon ablation: 1-year outcomes of the AURORA registry

Abstract Background and Objectives A novel irrigated radiofrequency balloon (RFB) for pulmonary vein isolation (PVI) integrated into 3D mapping system was recently launched. Methods Patients ablated for paroxysmal atrial fibrillation (PAF) or persistent atrial fibrillation (persAF) at two German high-volume electrophysiology centers were included into the prospective AURORA registry. All patients underwent clinical follow-up (FU) at 90, 180 and 360 days following ablation including 24h Holter ECGs. Results A total of 101 patients were enrolled (50 from centre A, 51 from centre B) and 86 patients (48% male, 65 ± 11 years, 55% PAF, 59 ± 7% left ventricular ejection fraction (LVEF)) completed the follow-up. Mean ablation and procedure times were 26 ± 13 min and 71 ± 20 min, respectively. Dose area product was 1501 ± 1634 mGycm2. Acute PVI was achieved in 100%. Atrial fibrillation (AF) free survival after a mean FU of 361 (219-375) days was 78.4% for PAF and 75.4% for persAF. (p= 0.828). A multiple regression analysis did not reveal any clinical or procedural predictors of AF recurrence among sex, age, BMI, left atrial diameter, LVEF, ablation time, procedure time and single shot PVI. However, early recurrence of atrial tachyarrhythmia (ERAT) was an independent predictor for AF recurrence at 1-year (Hazard Ratio [HR]: 3.198; 95% confidence interval [95% CI]: 1.036 - 10.32, p value = 0.0433). Primary adverse events occurred in 3.5% of patients (1 postprocedural pharyngeal bleeding, 1 myocardial infarction, 1 non-cardiovascular death); no pericardial effusion, stroke or phrenic nerve paralysis were observed. Conclusions RFB-based PVI is clinically effective and safe. ERAT at the first follow-up visit is an independent predictor of late AF recurrence.

One shot "fire & ice"

Abstract Introduction Pulmonary vein isolation (PVI) is the best and first strategies during ablation of atrial fibrillation (1-4). Short- and long-term effectivity as well as procedure time are important parameters during PVI-ablation. New efforts are made to find longer effectivity, low risk of the procedure and shorter procedure. Purpose The aim of our study is to compare the two "balloon - one shot" methods (radiofrequency balloon "RFB" and cryoballoon "CB") in terms of speed, efficacy and safety. Methods Prospective, randomized, pilot single-center trial including 74 consecutive patients with paroxysmal, persistent or long lasting persistent atrial fibrillation who undergo for the first time PVI-ablation between December 2022 and October 2023. Patient were randomized 1:1 according type of AF, Sex, Hypertension, left ventricular ejection fraction e left atrial volume in a multi-electrode radiofrequency balloon catheter Heliostar ablation or in cryoballoon system ablation. Both groups had comparable clinical characteristics. Results Median Age of the population was 64 year (iq range 57-70), 19 were female (25,7%), 31 patients (42%) had paroxysmal atrial fibrillation, median EF was 60% (iq range 55-65) and median left atrial volume 36 ml/mq (iq 28-40). 37 patients undergo cryoballoon PVI and 37 patients undergo RF balloon Ablation. Compared with the RFB group, the CB group showed a shorter procedure time [65 minutes (55-75) vs. 75 minutes (65-90) (P < 0.008)]. The DAP (dose area product) was lower in RFB Group [7 Gy*cm2 ( 5-10) vs CB Group 11 ( 7-18), p<0,001]. First-pass isolation was comparable. We had 5 complications in RFB group (1 pericardial effusion without pericardiocentesis, 3 transitory ST-elevation on ECG due to air embolism, 1 transient phrenic nerve palsy) and 3 complications in CB group (3 transient phrenic nerve palsy) P=ns. During the procedures in 3 cases of RF group and in 1 case of CB group (p=ns) we had to change the balloon due to technical issues. Conclusion The RFB appears to have a safety and efficacy profile similar to that of the CB for PVI. CB has shorter procedural times but with a higher X-Ray exposure.Figure 1Figure 2

Role of BMI on radiation dose in patients undergoing pulmonary vein isolation by pulsed field, cryoballoon and high-power-short-duration radiofrequency ablation

Abstract Background Different ablation modalities for pulmonary vein isolation (PVI) have been established. Since recent data from a randomized trial showed non-inferiority for pulse field ablation (PFA) vs. cryoballoon (CBA) or radiofrequency ablation (RFA) it seems reasonable to evaluate procedural parameters of these modalities in specific subgroups. Purpose The aim of this study was to evaluate radiation dose and procedural parameters in patients with body mass index (BMI) >26 kg/m² vs. ≤26 kg/m² undergoing PVI with different modalities. Methods Data of n=409 patients (140 PFA, 125 CBA, 144 RFA) having undergone PVI in three German centers for either paroxysmal or persistent atrial fibrillation were analysed. The primary endpoint was total radiation dose (Dose Area Product, DAP). Patients were analyzed with respect to BMI> vs. ≤26 kg/m² in PFA, CBA and RFA (with high-power short duration applications) groups, respectively. Secondary endpoints were radiation time and procedure time. Results The study included predominantly male patients (63.1%) with a mean age of 67.8±10.5 years. Cardiovascular risk factors were comparable within the groups, while the overall CHA2DS2-VASc-score was higher in CBA patients, which was largely influenced by a higher proportion of women in the CBA group. BMI was well balanced between the modalities (PFA: 28.7±5.6 kg/m² vs CBA: 28.5±6.0 kg/m² vs HPSD-RFA: 28.3±4.8 kg/m², p=0.78) as well as the proportion of patients with extreme obesity (BMI >30 kg/m²). The overall DAP was the lowest in the PFA group (370.2±274.6 µGym2) followed by HPSD-RFA (471.4±385.3 µGym2) and the highest in the CBA (1260.9±1053.5 µGym2) group. The radiation time was longest in the CBA group (16.6±17.0min) while being comparatively lower in PFA and HPSD-RFA groups (9.4±6.8 vs. 9.4±5.8 min). Procedure time was the shortest in the PFA group (79.6±30.5min), while being longest in the HPSD-RFA group (111.9±55.3 min). When stratifying patients according to BMI> 26 kg/m², there was a significant increase in DAP in all modalities, with the lowest mean increase in DAP in the PFA group (Δ143.84 µGym2), followed by HPSD-RFA (Δ329.54 µGym2) and the highest increase in the CBA group (Δ691.17 µGym2) (Figure 1). No difference was observed in radiation or procedure time when stratifying patients to BMI. (Figure 2) Conclusion Our study analyzing differences of radiation exposure according to elevated BMI among various PVI techniques shows that while there is a significant increase of DAP in patients with BMI >26 kg/m² in all modalities, the lowest increase is registered in the PFA collective. These results suggest that PVI performed with PFA, if available, or HPSD-RFA should be the energy sources of choice in obese patients with respect to radiation exposure.

Assessing the impact of 3D imaging assistance on efficiency and safety in atrial fibrillation cryoablation

Abstract Introduction Pulmonary vein (PV) isolation is a cornerstone therapy for symptomatic atrial fibrillation (AF). Current 3D-navigation technologies used with radiofrequency (RF) ablation allow drastic reduction of X-ray exposure and better anatomical characterization improving acute and long-term procedural results. Cryoballoon ablation (CA) procedures typically rely on conventional fluoroscopy, resulting in significant X-ray exposure. Although contemporary fluoroscopy technologies allow for potential 3D imaging integration, their specific utility in improving procedural guidance during CA remains undefined. Method Using semi-automatic segmentation obtained from pre-procedural cardiac computed tomography, 3D segmentations of the left atrium, including PV, spine and primary bronchi walls were fused on the real-time fluoroscopy acquisitions in three standard positions (AP, LAO, RAO), acquired at the beginning of the procedure (Figure1). We compared procedural characteristics of CA performed with 3D-fusion imaging to conventional fluoroscopy-guided procedures. Results Thirty-six patients (aged 60±13 yo, 85% male) with paroxysmal AF treated with CA were included in the study: 18 in the control group (conventional fluoroscopy) and 18 in the 3D-assisted group. Acute PV isolation was achieved in all patients. The 3D-assisted CA was associated with significantly shorter procedure duration (mean 97.8±15.5 vs 82.1±16.1 min, p=0.0048); left-sided dwelling time (mean 77±15.2 vs 65.1±14.4 min, p=0.0351); and lower X-ray energy delivered to the patient (Dose Area product) with mean 661±373.1 vs 378.1±316.8 cGy*cm2 (p=0.013). Interestingly, we found that 72.2% of 3D guided procedures were done in less than 90min, while 77.8% of conventional cases required more than 90min to be completed (Figure 2D). Conclusion 3D-fusion imaging integration is feasible and allows for an exact PV anatomy depiction on fluoroscopy. Our data illustrates that it might significantly improve CA efficiency (shorter procedure duration) and safety (lower X-ray exposure and left-sided dwelling time). Our approach could also impact long-term results since it might reduce the likeability of missing intermediate PVs. Further research is needed to evaluate the incremental value of 3D imaging in long term efficacy.Figure 1Figure 2

Pulsed-field ablation of atrial fibrillation in elderly and frail patients: procedural efficacy and safety from a single-center experience

Abstract Introduction The demographic data shows a growing population, mostly elderly and with multiple comorbidities, therefore becoming increasingly frail. In this context Atrial fibrillation (AF) is the predominant sustained arrhythmia, and over the years trans-catheter isolation of pulmonary veins (PVI) has become a crucial approach in AF treatment. Among the technologies and energy resources employed through the years to perform atrial fibrillation transcatheter ablation, a novel technique has recently begun to gain ground, specifically pulsed-field ablation (PFA). PFA employs sequential brief and high amplitude electrical pulses to induce selective and irreversible electroporation of the myocardium, leading to cell death. The high selectivity of the lesion, ensured by the lower electroporation threshold of myocardial tissue compared to adjacent anatomic structures, allows for a decrease in potential complications associated with conventional thermal ablation. Purpose To assess the efficacy and safety in the use of pulsed field ablation in a selected population of elderly and frail patients undergoing atrial fibrillation ablation. Method We conducted a retrospective study focusing on elderly and frail patients admitted to our centre for paroxysmal or persistent AF ablation. The inclusion criteria were: age greater than 75 years and a Clinical Frailty Scale ≥ 5. The study population consisted of 26 patients [male gender 18, mean age 78 ± 3 years] including 8 who were affected by an oncological or haematological disease at the time of admission. The majority of patients were affected by paroxysmal AF while two of them presented persistent AF (9%). The primary ablation endpoint was the pulmonary vein isolation (PVI) that was achieved by delivering an energy of 2 kV over 8 applications, employing an alternating approach between the two configurations of the basket and flower catheter for each individual vein. Results The short-term success, represented by the complete and verified electrical isolation of the veins was achieved in all 26 patients without any periprocedural complications. First-pass pulmonary vein isolation (FPI) was universally achieved among the patient in study, with a mean skin-to-skin procedural time of 70 ± 30 minutes. From the procedural data perspective, ablation was achieved using an average fluoroscopy time of 22 ± 8.4 minutes and an average dose area product (DAP) of 1320 cGy×cm2. Conclusions In elderly and frail patients, we assessed the efficacy and safety of ablative procedures using the PFA technique. Successful electrical PVI was achieved without additional touch-ups, thanks to a high FPI rate. This results in lower procedural times and shorter intra-operative radiation exposure. These data confer an augmented value within the elderly-frail population, wherein shorter procedural times contribute to a better postoperative course, characterized by reduced bed rest and shorter intra-hospitalization periods.

High power short duration and very high power short duration protocol: a comparison between two effective strategies of atrial fibrillation transcatheter ablation with radiofrequency

Abstract Introduction Radiofrequency (RF) is the most widely used technique for atrial fibrillation (AF) ablation. Aiming to achieve durable pulmonary vein isolation (PVI) with reduced procedural time and potential thermal side effects, high power short duration (HPSD) and very-high power short duration (v-HPSD) protocols have been developed, exploiting the use of the latest catheter generations. Purpose To assess safety and efficacy of AF ablation using two distinct HPSD settings, aiming to determine the most effective protocol for trans-catheter RF AF ablation. Methods We conducted a retrospective study including patients with paroxysmal or persistent AF: 100 were treated with the HPSD protocol and 100 patients with the v-HPSD one. In the HPSD protocol, RF energy at 40 W was applied for up to 20 seconds for the anterior segments of the pulmonary vein (PV), and 50 W up to 10 seconds for the posterior segments of the PV and the posterior wall (PW). Conversely, in the v-HPSD protocol RF pulses were applied at 50 W with an ablation index (AI) 500 in the anterior segments of PV and 90 W up to 4 sec for the posterior segment of the PV and the PW. Safety and efficacy were assessed during the procedure, during the hospital stay and throughout the entire follow-up duration. Results No relevant clinical and echocardiographic differences were identified between the two groups. Successful PVI and PW isolation was achieved in all cases. The v-HPSD group demonstrated a higher first-pass isolation (FPI) rate compared to the HPSD group. In contrast, the HPSD group exhibited a greater impedance drop (ID), supported by a higher contact force (CF). The RF total time, the procedural time, and the dose-area product (DAP) were significantly lower in the v-HPSD group. No periprocedural complications were reported. During the follow-up no significant differences in AF recurrence rates have been observed. Conclusions The absence of procedural complications underscores the high safety of both protocols. In our study, the v-HPSD group exhibited a superior FPI rate, indicative of enhanced acute efficacy; however it is crucial to underline that the HPSD group included a higher proportion of patients with a history of prior AF ablation. The more elevated ID observed in the HPSD group, indicating the exceptional quality of lesions, could be related to the major conductive heating component compared to v-HPSD. This results in deeper lesions and a more significant ID. Conversely, the brief duration of applications in the v-HPSD protocol contributes to reduce procedural times and diminish radiation exposure. Despite procedural disparities, the follow-up period reveals a low recurrence rate of AF in both groups, emphasizing the effectiveness of both HPSD and v-HPSD protocols in AF treatment.Kaplan-Meier Curve

Activation map of koch triangle: a novel approach to AVNRT ablation using CARTO 3 v7

Abstract Background Ablation of slow pathway (SP) is the standard approach for atrioventricular nodal reentry tachycardia (AVNRT) treatment (1). Low-voltage bridge is an optimal target during mapping using low x-ray exposure (2,3). Purpose We want to assess a new tool to identify SP by activation mapping of Koch’s triangle using CARTO PRIME V7 Methods Triangle of Koch 3D-activation map were obtained from intracardiac contact mapping during low x-ray CARTO 3 procedures (Figure 1). In 60 patients (39 % males, mean age 60.3 ± 14.7 years) undergoing ablation for AVNRT, an automatic activation map using a DECANAV mapping catheter and CARTO Confidense, Coherent, and FAM DX software modules were obtained. Results We indentified SP in all patients as the latest atrioventricular node activation area; RF catheter ablation (RFCA) elicited junctional beats. The mean dose-area product (DAP) was 16.5 ± 2.7 cGy/cm2, the mean fluoroscopy time exposure was 2.9 ± 2 min, the mean ablation index was 428.6 ± 96.6, and the mean contact force was 8 ± 2.8 g. There were no adverse event during the procedure and no AVNRT recurrences during a mean follow-up of 14.3 ± 8.3 months. Conclusions Ablation of the SP by automatic mapping using Confidense, Coherent, and FAM DX software modules is a new approach to AVNRT ablation. The CARTO3 V7 system defines a 3D map of the latest AV node activation area during sinus rhythm allowing a highly effective RFCA under low fluoroscopy time exposure without recurrences or AV blocks.Figure 1

Single versus double transseptal puncture for pulmonary vein isolation with radiofrequency catheter ablation for atrial fibrillation - insights from "Go for Zero Fluoroscopy" registry

Abstract Background Transseptal puncture is one of the most challenging steps in catheter ablation of atrial fibrillation (AF) because of the potential risk of complication. While single TSP reduces the puncture-related risk, double TSP simplifies the procedure (immediate signal visualization in pulmonary veins, avoidance of multiple changes of catheters through the single sheath). The purpose of this study was to analyze the impact of single versus double TSP during pulmonary vein isolation (PVI) with radiofrequency (RF) catheter ablation for AF on the fluoroscopy usage and procedure time. Methods Data reported from the international, multicenter prospective „Go For Zero Fluoroscopy Registry" performed in years 2018–2019 were analyzed. Overall 25 European electrophysiology centers from 14 countries and up to 5 operators from each center were enrolled. Only isolated PVI procedures were analyzed. Results A total data of 393 PVI RF procedures were collected from 25 centers. The median dose-area-product (DAP), fluoroscopy time and overall procedure time were: 810 (325 – 1839) cGy*cm2, 8 (4 – 14) minutes and 124 (92 – 168) minutes, respectively. Single TSP was associated with significantly higher DAP: 984 (459 – 1939) vs 667 (227 – 1469) cGy*cm2 (p=0.002), longer fluoroscopy time: 11 (6 – 19) vs 6 (3 – 11) minutes (p<0.001) and longer overall procedure time: 133 (103 – 168) vs 110 (90 – 168) minutes (p=0.003) as compared with double TSP. Single and double TSP group did not differ significantly in regards of general anesthesia usage, circular and multipolar mapping catheter use (p>0.05). However, single TSP was performed by operators with longer EP lab experience: 10 (4 – 15) vs 3 (0 – 10) years (p<0,001). Conclusions Double TSP is related with lower fluoroscopy usage and shorter overall procedure time of pulmonary vein isolation with radiofrequency catheter ablation for atrial fibrillation.

Advanced pulsed field ablation: comprehensive analysis of safety and efficacy in a real-world cohort

Abstract Background Pulsed field ablation (PFA) represents a novel energy modality for catheter ablation of atrial fibrillation (AF). Initial preclinical and clinical studies indicate a higher safety profile with promising efficacy outcomes as well as shorter procedure times. Real world data are sparce and methods to improve clinical success rates are under development. Methods In this observational study 124 patients underwent pulmonary vein isolation with PFA (Farapulse, Boston) for paroxysmal and persistent AF. For anatomical visualization and optimal positioning of the PFA catheter a 3D mapping system was used (Ensite X, Abbott). Patients were followed over a 15-month period to evaluate both efficacy and safety of PFA in a real-world cohort using an advanced mapping technology. Results The patient cohort had a mean age of 67 ± 11 years, 38% females (n= 47), paroxysmal AF 53% (n = 66), persistent AF 47% (n = 58). Acute pulmonary vein isolation (PVI) rate was 100%. After a median FU of 6 months, 17 patients (14%) had a recurrence of AF. In our study population no esophageal complications, pulmonary vein stenosis, or persistent phrenic palsy occurred. Major complications were observed in 2.4% of the cases (3/124), involving two pericardial tamponades (1.6%) and one vascular complication with intervention (0.8%). There were no stroke events and no occurrences of death. Noteworthy was the absence of complications such as coronary arterial spasm or hemolysis-related acute renal failure. The average dose-area product and average procedure time were 9.54 ± 7.68 µGym² and 57.94 ± 18 minutes, respectively. Conclusion PVI with PFA in a real world cohort demonstrates a high safety profile. Furthermore, high clinical success rates can be achieved also in mixed paroxysmal/persistent AF populations. The use of 3D mapping systems might even improve clinical outcomes of PVI with PFA and will also help to guide more complex ablation strategies in the future. These findings pave the way for further exploration into the long-term benefits and broader applicability of PFA in AF ablation.

Comparative Analysis of Transpedal and Transfemoral Access During Genicular Artery Embolization for Knee Osteoarthritis.

This retrospective study aimed to compare the efficacy and safety of transpedal access (TPA) with transfemoral access (TFA) in Genicular Artery Embolization (GAE). 60 patients who underwent GAE between January and June 2023, were recruited and outcomes were compared between the TFA (n = 37) and TPA (n = 23) groups. Technical and clinical success rates, complications, and patient-reported outcomes were assessed. All patients attained a 100% technical success rate, which was defined as the successful selective catheterization and embolization of at least one feeding artery to the knee joint, without encountering any major complications. Minor complications, observed in 12/60 patients (20%), were predominantly manifested as a transient skin discoloration. The TPA group had a comparatively higher (p = 0.008) rate of minor complication than the TFA group. Notably, TPA was associated with a longer duration of the procedure (p = 0.013), duration of fluoroscopy (p = 0.004), increased total air kerma (p = 0.037), dose-area product values (p = 0.021), and a greater incidence of vasospasm (p = 0.018) than TFA. However, TPA patients reported shorter recovery times and less post-procedural discomfort, especially reduced back pain due to postinterventional bedrest (p < 0.001). At the 3-month follow-up, the clinical success rate was similar between the two groups (p = 0.905). TFA is the safer and faster method for GAE, offering fewer complications and reduced radiation exposure. For patients with challenging groin anatomies, however, TPA may provide a valuable alternative.

National Diagnostic Reference Levels for Standard Descending Thoracic Endovascular Aortic Repair and Optimisation Strategies

The International Commission on Radiological Protection has highlighted the large number of medical specialties that use fluoroscopy outside diagnostic imaging departments without radiation protection programmes for patients and staff. Vascular surgery is one of these specialties. Thoracic endovascular aortic repair (TEVAR) is a complicated procedure requiring radiation protection guidance and optimisation. The recent EU Basic Safety Standards Directive requires the use and periodic updating of diagnostic reference levels (DRLs) for interventional procedures. The aim of this study was to determine doses for patients undergoing TEVAR with mobile Xray systems and hybrid rooms (fixed Xray systems) to obtain national DRLs and to suggest optimisation actions. This was a retrospective cross sectional study. The Spanish Chapter of Endovascular Surgery conducted a national survey in 11 autonomous communities representing around 77.6% of the Spanish population (47.33 million inhabitants). A total of 266 TEVAR procedures from 17 Spanish centres were analysed, of which 53.0% were performed in hybrid operating rooms. National DRLs were obtained and defined as the third quartile of the median values from the different participating centres. The proposed national DRLs are: for kerma area product (KAP), 113.81 Gy·cm2 for mobile Xray systems and 282.59 Gy·cm2 for hybrid rooms; and for cumulative air kerma (CAK) at the patient entry reference point, 228.38 mGy for mobile systems and 910.64 mGy for hybrid rooms. Based on the requirement to know radiation doses for standard endovascular procedures, this study of TEVARs demonstrated that there is an increased factor of 2.48 in DRLs for KAP when the procedure is performed in a hybrid room compared with mobile C-arm systems, and an increased factor of 3.98 in DRLs for CAK when the procedure is performed with hybrid equipment. These results will help to optimise strategies to reduce radiation doses during TEVAR procedures.

Expansion of Typical Values for Paediatric Patients in Ireland and Comparison with Published DRLs - Experiences of a Single Institution

IntroductionTo reduce the risks involved with ionising radiation exposure, typical values (TVs) and diagnostic reference levels (DRLs) have been established to help keep radiation doses ‘as low as reasonably practicable. TVs/DRLs provide standardised radiation dose metrics that can be used for comparative purposes. However, for paediatrics, such values should consider the size of the child instead of their age. This study aimed to establish and compare paediatric TVs for chest, abdomen and pelvis radiography. MethodsStudy methods followed processes for establishing paediatric DRLs as outlined by the Health Information and Quality Authority (HIQA). Kerma-area product (KAP) values, excluding rejected images, were retrospectively acquired from the study institution's Picture Archiving and Communications System (PACS). Paediatric patients were categorised into the following weight-based groupings (5 to <15 kg, 15 to <30 kg, 30 to <50 kg, 50 to 80 kg) and stratified based on the examination that was performed (chest, abdomen, and pelvis), and where it was performed (the different X-ray rooms). Anonymised data were inputted into Microsoft Excel for analysis. Median and 3rd quartile KAP values were reported together with graphical illustrations. ResultsData from 407 X-ray examinations were analysed. For the previously identified weight categories (5 to <15 kg, 15 to <30 kg, 30 to <50 kg, 50 to 80 kg), TVs for the chest were 0.10, 0.19, 0.37 and 0.53 dGy.cm2, respectively. For the abdomen 0.39, 1.04, 3.51 and 4.05 dGy.cm2 and for the pelvis 0.43, 0.87, 3.50 and 7.58 dGy.cm2. Between X-ray rooms TVs varied against the institutional TVs by -60 to 119 % (chest), -50 to 103 % (abdomen) and -14 and 24 %% (pelvis). ConclusionTVs in this study follow established trends with patient weight and examination type and are comparable with published literature. Variations do exist between individual examination rooms and reasons are multifactorial. Given that age and size do not perfectly correlate further work should be undertaken around weight-based TVs/DRLs in the paediatric setting.

Estimating brain and eye lens dose for the cardiologist in interventional cardiology-are the dose levels of concern?

To establish conversion coefficients (CCs), between mean absorbed dose to the brain and eye lens of the cardiologist and the air kerma-area product, PKA, for a set of projections in cardiac interventional procedures. Furthermore, by taking clinical data into account, a method to estimate the doses per procedure, or annual dose, is presented. Thermoluminescence dosimeters were used together with anthropomorphic phantoms, simulating a cardiologist performing an interventional cardiac procedure, to estimate the CCs for the brain and eye lens dose for nine standard projections, and change in patient size and x-ray spectrum. Additionally, a single CC has been estimated, accounting for each projections fraction of use in the clinic and associated PKA using clinical data from the dose monitoring system in our hospital. The maximum CCs for the eye lens and segment of the brain, is 5.47 μGy/Gycm2 (left eye lens) and 1.71 μGy/Gycm2 (left brain segment). The corresponding weighted CCs: are 3.39 μGy/Gycm2 and 0.89 μGy/Gycm2, respectively. Conversion coefficients have been established under actual scatter conditions, showing higher doses on the left side of the operator. Using modern interventional x-ray equipment, interventional cardiac procedures will not cause high radiation dose levels to the operator when a ceiling mounted shield is used, otherwise there is a risk that the threshold dose values for cataract will be reached. In addition to the CCs for the different projections, methods for deriving a single CC per cardiac interventional procedure and dose per year were introduced.

Augmented fluoroscopy-guided dye localization for small pulmonary nodules in hybrid operating room: intrathoracic stamping versus transbronchial marking.

We developed a novel augmented fluoroscopy-guided intrathoracic stamping technique for localizing small pulmonary nodules in the hybrid operating room. We conducted an observational study to investigate the feasibility of this technique and retrospectively compared two augmented fluoroscopy-guided approaches: intrathoracic and transbronchial. From August 2020 to March 2023, consecutive patients underwent single-stage augmented fluoroscopy-guided localization under general anaesthesia. This included intrathoracic stamping and bronchoscopic lung marking, followed by thoracoscopic resection in a hybrid operating room. Comparative analyses were performed between the two groups. The data of 50 patients in the intrathoracic stamping and 67 patients in the bronchoscopic lung marking groups were analysed. No significant difference was noted in demographic data between the groups, except a larger lesion depth in the bronchoscopic lung marking group (14.7 ± 11.7 vs 11.0 ± 5.8mm, p = 0.029). Dye localization was successfully performed in 49 intrathoracic stamping group patients (98.0%) and 67 bronchoscopic lung marking group patients (100%). No major procedure-related complications occurred in either group; however, the time flow (total anaesthesia time/global operating room time) was longer, and the radiation exposure (fluoroscopy duration/total dose area product) was larger in the bronchoscopic lung marking group. Augmented fluoroscopic stamping localization under intubated general anaesthesia is feasible and safe, providing an alternative with less global operating room time and lower radiation exposure for image-guided thoracoscopic surgery in the hybrid operating room.

QUANTIFYING RADIATION EXPOSURE IN THE RADIOLOGICAL INVESTIGATION OF NON-ARTHRITIC HIP PAIN

Radiological investigations are essential in the work-up of patients presenting with non-arthritic hip pain, to allow close review of the complex anatomy around the hip and proximal femur. The aim of this study is to quantify the radiation exposure associated with common radiological investigations performed in assessing young adult patients presenting with non-arthritic hip pain.A retrospective review of our UK tertiary hip preservation centre institutional imaging database was performed. Data was obtained for antero-posterior, cross-table lateral and frog-lateral radiographs, along with data for the low dose CT hip protocol and the Mako CT Hip protocol. The radiation dose of each imaging technique was measured in terms of dose-area product (DAP) with units of mGycm2, and the effective doses (ED, mSv) calculated.The mean effective radiation dose for hip radiographs was in the range 0.03 to 0.83mSv (mean DLP 126.7–156.2 mGycm2). The mean effective dose associated with the low-dose CT hip protocol was 3.04mSv (416.8 mGycm2) and for the Stryker Mako CT Hip protocol was 8.4mSv (1061 mGycm2). The radiation dose associated with use of CT imaging was significantly greater than plain radiographs (p&lt;0.005)Investigation of non-arthritic hip pain can lead to significant ionising radiation exposure for patients. In our institution, the routine protocol is to obtain an anteroposterior radiograph and then a specific hip sequence 3 Tesla MRI including anteversion views. This provides the necessary information in the majority of cases, with CT scanning reserved for more complex cases where we feel there is a specific indication. We would encourage the hip preservation community to carefully consider and review the use of ionising radiation investigations.

Embolization of Middle Meningeal Arteries for Symptomatic Subacute Subdural Hematoma in Patients with Cancer

PurposeThe purpose of this study was to evaluate the technical and clinical success of middle meningeal artery (MMA) embolization performed for symptomatic subacute subdural hematoma (SDH) in patients with cancer. MethodsThis study retrospectively included 23 consecutive patients (12 men, 11 women; median age 61 years, interquartile range: 55.5–75.5) who underwent 34 MMA angiograms for symptomatic SDH in 2022 and 2023. Median SDH thickness was 10.5mm (7-12). Median platelet count was 117 K/mcL (54.5–218). Ten patients (43.5%, 10/23) had hematologic malignancies, 7 patients (30.4%, 7/23) had surgery. Fluoroscopy time (FT), reference dose (RD), and kerma area product (Kap) were analyzed. Adverse events and outcomes were recorded. ResultsThe median imaging and clinical follow-up were 65 days (36.5–190.5) and 163 days (86–274), respectively. The technical success rate was 91.2% (31/34) as 3 MMA were not identified in 2 patients. Median procedure duration was 61 min (55.5–75.5). Median FT was 21.6 min (15.5–31.8); median RD was 158 mGy (96–256); and median Kap was 32.9 Gy.cm2 (20.4–45.1). No further intervention was needed. For 16 patients, SDH resolved after in median 59.5 days (50-90). For 7 patients, SDH remained visible on the last imaging follow-up performed at 24 days in median (6.5-36.5). No predictive factor of failure was identified. The adverse event rate was 1/23 (4.3%). Eight patients (34.8%, 8/23) died during follow-up from progression of cancer. ConclusionsMMA embolization of symptomatic SDH in patients with cancer appears safe and is associated with improvement in clinical symptoms.

Assessing the Efficacy of RADPAD Protection Drape in Reducing Radiation Exposure to Operators in the Cardiac Catheterization Laboratory: A Systematic Review and Meta-Analysis.

One of the leading environmental hazards, ionizing radiation, is linked to several detrimental health consequences in the body. RADPAD(Worldwide Innovations & Technologies, Inc., Kansas City, Kansas) is a sterile, lead-free, lightweight, disposable radiation protection shield. We conducted a systematic review and meta-analysis to determine the effectiveness of RADPAD protection drapes in the cardiac catheterization lab and how they can aid interventional cardiologists in becoming subjected to less scatter radiation. PubMed, Embase, and Google Scholar were searched for studies discussing the efficacy of RADPAD protection drapes in reducing radiation exposure to operators in the cardiac catheterization laboratory. A random-effects model was used to pool odds ratios (ORs) and 95% confidence intervals (CIs) for endpoints: primary operator exposure dose, dose area product (DAP), relative exposure, and screening time. Our analysis included 892 patients from six studies. Compared to the No-RADPAD group, primary operator exposure dose (E) was significantly lower in the RADPAD group (OR: -0.9, 95% CI: -1.36 to -0.43, I2= 80.5%, p = 0.0001). DAP was comparable between both groups (OR: 0.008, 95% CI: -0.12 to -0.14, I2= 0%, p = 0.9066). There was no difference in the relative exposure (E/DAP) (OR: -0.47, 95% CI: -0.96 to 0.02, I2= 0%, p = 0.90) and screening time (OR: 0.13, 95% CI: 0.08 to 0.35, I2= 0%, p = 0.22) between the two groups. The interventional cardiology laboratory is exposed to significantly less scatter radiation during procedures owing to the RADPAD protective drape. Consequently, all catheterization laboratories could be advised to employ RADPAD protective drapes.