Balloon Size Research Articles

Intravascular imaging of angioplasty balloon under-expansion during pre-dilation predicts hyperelastic behavior of coronary artery lesions.

Introduction: Stent-induced mechanical stimuli cause pathophysiological responses in the coronary artery post-treatment. These stimuli can be minimized through choice of stent, size, and deployment strategy. However, the lack of target lesion material characterization is a barrier to further personalizing treatment. A novel ex-vivo angioplasty-based intravascular imaging technique using optical coherence tomography (OCT) was developed to characterize local stiffness of the target lesion. Methods: After proper institutional oversight, atherosclerotic coronary arteries (n = 9) were dissected from human donor hearts for ex vivo material characterization <48h post-mortem. Morphology was imaged at the diastolic blood pressure using common intravascular OCT protocols and at subsequent pressures using a specially fabricated perfusion balloon that accommodates the OCT imaging wire. Balloon under-expansion was quantified relative to the nominal balloon size at 8 ATM. Correlation to a constitutive hyperelastic model was empirically investigated (n = 13 plaques) using biaxial extension results fit to a mixed Neo-Hookean and Exponential constitutive model. Results and discussion: The average circumferential Cauchy stress was 66.5, 130.2, and 300.4kPa for regions with <15, 15-30, and >30% balloon under-expansion at a 1.15 stretch ratio. Similarly, the average longitudinal Cauchy stress was 68.1, 172.6, and 412.7kPa, respectively. Consequently, strong correlation coefficients >0.89 were observed between balloon under-expansion and stress-like constitutive parameters. These parameters allowed for visualization of stiffness and material heterogeneity for a range of atherosclerotic plaques. Balloon under-expansion is a strong predictor of target lesion stiffness. These findings are promising as stent deployment could now be further personalized via target lesion material characterization obtained pre-operatively.

Evaluación del tracto de salida del ventrículo derecho mediante resonancia magnética con flujo 4D en pacientes sometidos a recambio valvular pulmonar transcatéter

Introduction and objectivesMagnetic resonance imaging (MRI) including 4D flow is used before percutaneous pulmonary valve implantation (PPVI). As PPVI is limited by the size of the right ventricular outflow tract (RVOT), accurate sizing is needed to plan the intervention. The aim of this study was to compare different MRI modalities and invasive angiogram to balloon sizing of RVOT. MethodsSingle-centre prospective study of patients who underwent PPVI for isolated pulmonary regurgitation assessed by 4D flow MRI, 3D steady-state free precession/gradient echo (3D SSFP/GRE) and contrast magnetic resonance angiogram. Balloon sizing was considered as the reference. ResultsA total of 23 adults were included (mean age, 38.4±12.5 years). Eighteen patients underwent successful primary PPVI. The average of the narrowest RVOT diameter was 25.4±4.3mm by balloon sizing. Compared to balloon sizing, RVOT diameters were better correlated when estimated by systolic 4D flow MRI (r=0.89, P<0.001) than by diastolic 4D flow MRI (r=0.71, P<0.001), 3D contrast magnetic resonance angiography (r=0.73; P<.001) and 3D SSFP/GRE (r=0.50; P=.04) and not significantly correlated when estimated by 2D in diastole and systole. The mean difference between systolic 4D flow MRI and balloon sizing was 0.2mm (95%CI, –3.5 to 3.9 mm), whereas it was wider with other techniques. ConclusionsBeyond the quantification of pulmonary valve regurgitation, 4D flow allows accurate estimation of RVOT diameters, especially in systole, which is fundamental before planning PPVI.

PO-01-169 CLINICAL APPLICATION OF A NOVEL 31MM CRYOBALLOON FOR PULMONARY VEIN ISOLATION FOR PAROXYSMAL ATRIAL FIBRILLATION: PROCEDURAL DATA FROM THE FIT ARM OF FROZEN AF

Cryoablation of pulmonary veins (PV)s to treat paroxysmal atrial fibrillation (PAF) is well established, however there are limited choices in balloon sizes for cryoablation. Data have recently been collected on a new cryoballoon system with novel capability to deliver cryoablation in a standard 28mm diameter balloon or an expanded 31mm diameter, using the same catheter. Demonstrate the clinical utility of an expandable diameter cryoballoon, and discuss the potential advantages for occlusion, antral positioning, and lesion size. As part of the FROZEN AF Trial (NCT04133168) 50 patients received PVI ablation to treat PAF with a cryoballon capable of ablation at 28mm or 31mm. Follow-up is continuing, but we present procedural data and clinical application of this balloon. The extension arm of the FROZEN AF trial (NCT04133168) included 50 pts, 46% female and aged 64±13 years, indicated for PV isolation for treatment of PAF. Acute isolation was successful in all pts. Average procedure time was 101±59 min, with LA dwell of 51 min, and fluoroscopy of 7 min. General anesthesia was used in all patients, and the majority (49/50) underwent a single transeptal puncture. The novel 31mm configuration was used in 65% of ablations. In the 198 ablations performed at 31mm, 97.5% achieved a Grade 3 or 4 occlusion. Average nadir temperature was -54.89°C, and average TTI was 44s. In PVs where the first ablation was performed at 31mm the single shot isolation rate was significantly higher than in PVs where the first ablation was performed at 28mm. Data by PV are listed in Table 1. Notably, there was a low rate of phrenic nerve impairment, with only 1 instance of transient paralysis which resolved prior to discharge. Additionally, in a subset of pts at a single center, occlusion was assessed at both 28mm and 31mm, Figure 1. Preliminary landmark-based analysis of a subset of veins suggests that inflation to 31mm results in a marked antral shift of balloon position. The combination of maneuverability and variable size may make this balloon particularly useful in addressing challenges resulting from patient-to-patient variability in PV size and geometry. In particular, the choice between 28 and 31mm diameter in a single device may facilitate obtaining good occlusion, and the more antral positioning of a large balloon may give physicians more discretion as to the size and location of PVI lesions. As, the FROZEN AF trial is ongoing, long-term results in these patients are awaited.Tabled 1Usage, Occlusion and Single Shot Isolation rate of 28 and 31mm Balloon Sizesn Grade 4 Occlusion / N Total Ablation (%)n Single Shot Isolation / N PV (%)Pulmonary Vein28mm31mm28mm31mmLeft superior (LSPV)18 / 23 (78.3)41 / 45 (91.1)2/8 (25%)19/34 (55.9%)Left inferior (LIPV)17 / 19 (89.5)29 / 38 (76.3)4/12 (33.3%)23/30 (76.7%)Left common (LCPV)5 / 7 (71.4)6 / 19 (31.6)0/0 (%)1/8 (12.5%)Left middle (LMPV)1 / 1 (100)-1/1 (100%)0/0 (%)Right superior (RSPV)9 / 18 (50)49 / 56 (87.5)1/5 (20%)27/43 (62.8%)Right inferior (RIPV)21 / 38 (58.3)33 / 37 (89.2)10/24 (41.7%)17/24 (70.8%)Right common (RCPV)1 / 3 (33.3)2 / 3 (66.7)0/1 (0%)0/1 (0%)Total72 / 109 (67.3)160 / 198 (80.8)18/51 (35.3%)87/140 (62.1%)Single shot success in veins where first ablation was performed with specified balloon size. Only ablations with duration > 60s included in ablation counts Open table in a new tab

PO-01-064 IMPROVED METHOD FOR VEIN OF MARSHALL ALCOHOL ABLATION: CASE SERIES

Vein of Marshall (VoM) alcohol ablation has emerged as a successful method to reduce recurrence of atrial fibrillation (AF) and atrial tachyarrhythmias in patients with persistent AF. Cannulation of the VoM close to the coronary sinus (CS) ostium with an IMA guiding catheter through an unsupported CS access catheter can be challenging; extending procedure/fluoroscopy time, contrast use, and increase the risk of complications. To describe new tools & techniques for VoM alcohol ablation that make the procedure easier. We describe here an improved method for VoM alcohol ablation in 4 patients following AF ablation. A baseline 3D left atrium voltage map was obtained to assess pre-existing scar (local bipolar voltage of <0.1 mV). The CS was cannulated via the right femoral vein with either a 6 French (F) decapolar catheter or a hand-shaped 6F multipurpose guiding catheter telescoped inside a long curved 9F inner diameter (ID) sheath. The sheath was then advanced into the CS body. Next, a 0.035 in Amplatz wire (short taper) was introduced through the sheath into the CS using a 5F outer diameter (OD) vein selector to provide extra support and facilitate easy re-cannulation of the CS in case the outer sheath disengaged. An occlusive venogram was conducted in RAO 20 view. After the identification of the VoM, a 5F vein selector was used to engage it and a 0.014 mm floppy wire was advanced. An over-the-wire angioplasty balloon (size 1.5 to 2mm x 6mm) was advanced in the VoM and dilated to occlude the vessel. Three ml of 98% ethanol were delivered over 1 minute. This process was repeated twice. The balloon was deflated, and the apparatus was retracted into the sheath. We then proceeded with repeat 3D voltage mapping to assess the ethanol-induced scar. Application of this workflow using these tools reduced the use of contrast, fluoroscopy time, and total procedural time in this case series. What is new: 1. The ID of the CS access sheath was increased to 9F. 2. An Amplatz (short taper) stabilizing/support wire was added to the CS access sheath. 3. The shape of the catheter used to engage the VOM was changed from IMA to vertebral. Application of these tools reduced the use of contrast, fluoroscopy time, and total procedural time.

Endoscopic severity of gastric sleeve stenosis can be quantified using impedance planimetry.

Gastric sleeve stenosis (GSS) is an adverse event following sleeve gastrectomy for which objective tools are needed for diagnosis and treatment. Endoscopic treatment with serial pneumatic balloon dilation may relieve symptoms and prevent the need for conversion to Roux-en-Y gastric bypass. Endoluminal functional impedance planimetry (EndoFLIP) is an endoscopic tool that measures luminal diameter and distensibility indices (DI) and could be used to characterize severity of GSS. This was a retrospective analysis of a prospective database of patients referred for symptoms suggestive of GSS. Severity was determined at each endoscopy by a bariatric endoscopist blinded to EndoFLIP measurements. Successive pneumatic balloon dilations were performed until symptoms resolved; failure was defined as referral for conversion. EndoFLIP measurements of stenosis diameter and DI were obtained pre- and post-dilation. Primary outcomes were pre- and post-dilation luminal diameter and DI of GSS. Secondary outcomes were endoscopic severity of GSS, patient characteristics, and need for surgical revision. 26 patients were included; 23 (85%) were female. Mean age was 45.3 (± 9.9) years. Mean number of dilations was 2.4 (± 1.3) and 10 (38%) patients were referred for conversion. Mild, moderate, and severe GSS was found in 10 (38%), 6 (23%), and 10 (38%) patients, respectively. Moderate and severe GSS underwent more dilations (2.5 ± 1.0 and 3.2 ± 1.6) than mild GSS (1.8 ± 0.8) and were more likely to be referred for conversion. Both pre- and post-dilation diameters were significantly larger in mild versus moderate or severe GSS. Additionally, pre- and post-dilation DI at 30ml were significantly higher for mild compared to moderate and severe GSS. EndoFLIP measurements correlate well with endoscopic assessment of GSS. While more data are needed to determine ideal balloon size and threshold measurements, our results suggest EndoFLIP may help expedite diagnosis and treatment of GSS.

4D flow magnetic resonance imaging to assess right ventricular outflow tract in patients undergoing transcatheter pulmonary valve replacement

Introduction and objectivesMagnetic resonance imaging (MRI) including 4D flow is used before percutaneous pulmonary valve implantation (PPVI). As PPVI is limited by the size of the right ventricular outflow tract (RVOT), accurate sizing is needed to plan the intervention. The aim of this study was to compare different MRI modalities and invasive angiography to balloon sizing of RVOT. MethodsSingle-center prospective study of patients who underwent PPVI for isolated pulmonary regurgitation assessed by 4D flow MRI, 3D steady-state free precession/gradient echo (3D SSFP/GRE) and contrast magnetic resonance angiography. Balloon sizing was considered as the reference. ResultsA total of 23 adults were included (mean age, 38.4±12.5 years). Eighteen patients underwent successful primary PPVI. The average of the narrowest RVOT diameter was 25.4±4.3 mm by balloon sizing. Compared to balloon sizing, RVOT diameters were better correlated when estimated by systolic 4D flow MRI (r=0.89, P<.001) than by diastolic 4D flow MRI (r=0.71, P <.001), 3D contrast magnetic resonance angiography (r=0.73; P <.001) and 3D SSFP/GRE (r=0.50; P=.04) and was not significantly correlated when estimated by 2D in diastole and systole. The mean difference between systolic 4D flow MRI and balloon sizing was 0.2 mm (95%CI, –3.5 to 3.9 mm), whereas it was wider with other techniques. ConclusionsBeyond the quantification of pulmonary valve regurgitation, 4D flow allows accurate estimation of RVOT diameters, especially in systole, which is fundamental before planning PPVI.

Use of an aortic balloon to achieve uterine conservation in a case of placenta accreta spectrum: A case report

Placenta accreta spectrum (PAS) is a rare complication of pregnancy associated with a high risk of massive haemorrhage and caesarean hysterectomy. This is a case report of abdominal aortic balloon occlusion, using intravascular ultrasound, to achieve uterine conservation in a case of severe PAS. The patient was a 34-year-old woman, G2P1, with one prior caesarean section. Antenatal imaging, consisting of transabdominal and transvaginal ultrasound, and magnetic resonance imaging, showed features of PAS. The risk of caesarean hysterectomy with PAS was explained, but the patient declared a desire to retain fertility. Following multi-disciplinary discussion, it was considered appropriate to attempt uterine conservation using en-bloc myometrial and placental resection. An elective caesarean delivery was performed at 36weeks of gestation. An aortic balloon was inserted prior to surgery using intravascular ultrasound, which allowed for radiation-free, point-of-surgery, accurate balloon sizing, by measuring the aortic diameter, and correct placement of the balloon in the abdominal aorta below the renal vessels. Intraoperative findings confirmed PAS, and a myometrial resection was performed. There were no intraoperative complications. Estimated blood loss was 1000mL and the patient had an uncomplicated postoperative course. This case demonstrates how the use of an intravascular intraoperative aortic balloon can facilitate uterine conservation in a case of severe PAS.

Abstract Number ‐ 188: Rescue Stenting for Intracranial Stenosis In ELVO patients Using Neuroform Atlas Stent Through Gateway Balloon

Introduction Management of acute large vessel occlusion due to intracranial stenosis remains challenging with high complication and poor recanalization rates. Morbidity is also related to the intracranial exchange that is required for stent placement after the rescue angioplasty. We aim to present our initial experience of deployment of Neuroform Atlas stent through the lumen of a Gateway angioplasty balloon to avoid microcatheter exchange. Methods Patients were identified from prospectively collected mechanical thrombectomy stroke database from Feb 2019 to July 2021. Demographic and clinical information was collected. Primary outcomes were favorable functional outcome at hospital discharge (modified Rankin Scale (mRS) score of 0–3), and the rate of intracranial hemorrhage (ICH). Good angiographic recanalization (TICI ≥ 2b), and mortality at 30 days were other outcomes. Results We identified 5 patients treated with this approach [mean age 54 ± 14 years, all were men] who presented with large vessel occlusion of middle cerebral artery. Initial median NIHSS was 8 (range 6–16) with one patient received IV t‐PA. Patient initially underwent mechanical thrombectomy using the Solumbra technique. Due to reocclusion or impending occlusion with evidence of atherosclerotic plaque, rescue angioplasty with stent placement was performed. Patients were loaded with 650 mg of aspirin and 180 mg of ticagrelor through nasogastric tube prior. Balloon angioplasty was performed using the gateway balloon size ranging from 1.5 to 3 mm which was inflated to subnominal pressures over 1 minutes. This was followed by placing Neuroform atlas stent through the gateway balloon with size ranging from 3 to 4 mm diameter and length ranges from 21–24 mm. TICI ≥ 2b was achieved in 4 patients. Mean time from symptoms onset to revascularization was (336 ± 90) minutes. One patient had asymptomatic ICH. 2 patients had mRs 0–3 at the time of discharge and one patient was dead at 1 month Conclusions Our preliminary experience showed lower risk of guidewire perforation as well as potentially decreased operative time and early reperfusion by deploying the Neuroform stent through a compatible gateway balloon microcatheter. This should be investigated further in a large multicenter study

Abstract No. 55 Evaluating Percutaneous Transhepatic Biliary Drainage (PTBD) Factors Associated with Better Outcomes in the Treatment of Post-Surgical Benign Biliary Strictures

To report outcomes of post-surgical benign biliary strictures treated with percutaneous transhepatic biliary drainage (PTBD) and balloon dilation. Patients with a history of surgery and who developed a benign biliary stricture were included in this retrospective, IRB-approved study (n = 44). Patients having biliary leaks, or with complete occlusion of the bile duct due to surgical clips were excluded (n = 28). Drain size, type (internal-external or external), balloon dilation, and type and size of balloon used was evaluated for all biliary procedures. These characteristics were compared between patients needing (n = 8) and not needing (n = 36) surgical revision. Continuous variables are reported as median (IQR) and compared with Wilcoxon rank sum test, categorical variables as numbers with percentages and compared using chi-square test. Patients were 59 (42-67) years old with 67% being female. Hepaticojejunostomy was the most common surgery (30%) followed by Roux-en-Y gastric bypass (16%), pancreaticoduodenectomy (14%), transplant (14%), Billroth II (9%), cholecystectomy (7%) and others (9%). Duct to enteric anastomosis was present in 52%, duct to duct in 11% and no anastomosis in 36%. Prior non-PTBD interventions included ERCP dilation and stent placement in 9 (20%) and failed ERCP in 10 (23%) patients. The first PTBD was done 28 (6-98) months after surgery, with a drain size of ≥10F in 20 (45%) and < 10F in 24 (55%) patients. The drain was internal-external in 41 (93%) patients. Patients underwent a total of 4 (3-8) procedures before drain removal, with drain upsizing performed in 23 (52%) patients, leading to a largest drain size of ≤8F in 10 (23%), 10F in 17 (39%), 12F in 14 (32%) and ≥14F in 3 (6%) patients. Balloon dilation was performed in 40 (91%) patients, with the largest balloon size being ≤8 mm in 13 (30%), 10 mm in 20 (45%), 12 mm in 6 (14%), and 14 mm in 1 (2%) patient. A cutting balloon was used in 19 (43%) patients. Surgical revision was needed in 8 (18%) patients, with a repeat PTBD performed in 5 (11%) patients. The rate of surgical revision was lower in patients who received a largest drain of ≥10F (12%) compared with those who received a largest drain of <10F (40%, P = 0.042). The rate of surgical revision was 7.4% in patients who were dilated with a balloon of ≥10 mm compared with 30.7% in those who were dilated with a balloon of <10 mm (P = 0.053). The median drain-free survival was 41 (11-57) months for the entire cohort. Postsurgical benign biliary strictures treated with PTBD with a drain of ≥10F and dilated with a balloon of ≥10 mm are less likely to need surgical revision.

Mid-Term Angiographic and Intracoronary Imaging Results Following Intracoronary Lithotripsy in Calcified Coronary Artery Disease: Results From Two Tertiary Referral Centres

BackgroundIntracoronary lithotripsy (IVL) is a safe and effective treatment for coronary calcification. Angiographic and intracoronary imaging follow-up have not yet been described. We aimed to describe the mid-term angiographic outcomes following IVL. MethodsPatients successfully treated with IVL in two tertiary referral hospitals were included. Repeat angiography and intracoronary imaging was performed. Quantitative coronary angiography (QCA) and optical coherence tomography (OCT) analyses were performed using dedicated workstations. ResultsTwenty patients were included; mean age 67.1 years, left anterior descending artery 55 %. Median IVL balloon size was 3.0 mm and a median of 60 pulses were delivered per vessel. Percentage stenosis by QCA was 60 % [IQR 51–70] reducing to 20 % post stenting (p < 0.001). On OCT, 88.9 % had circumferential calcium. IVL resulted in fractures in 88.9 %. Resulting minimum stent expansion was 91.75 % [IQR 81.5–108].Follow-up was at a median of 22.7 months [IQR16.4–25.5]. Percentage stenosis by QCA was 22.5 % [IQR 14–30] and not significantly different from the index procedure (p > 0.05). Minimum stent expansion by OCT was 85 % [IQR 72–97]. Late luminal loss was 0.15 mm [IQR −0.25 to 0.69]. Binary angiographic instent restenosis (ISR) was 10 % (2 of 20 patients). OCT demonstrated a predominantly homogenous neointimal pattern with high backscatter. ConclusionFollowing successful IVL treatment, repeat angiography demonstrated preserved stent parameters in the majority of patients with favorable vascular healing properties by OCT. A binary restenosis rate of 10 % was observed. These results suggest durable results following IVL treatment of severe coronary calcification however larger studies are warranted.

Safety and Efficacy of OPN Balloon in Patients With Calcified Coronary Artery Disease

BackgroundPatients with symptomatic calcified coronary lesions have poor outcomes. Such lesions require additional atherectomy devices for bed preparation. AimTo assess the safety and efficacy of OPN balloon in patients with calcified coronary lesions. MethodsThis is an investigator-initiated, prospective, observational study. The primary outcome of the study was a procedural success. ResultsWe studied 71 patients (133 lesions). Maximum lesions were located in LAD [46.6 %]. The OPN balloon was used for pre-dilatation alone in 28.6 % (Pre-stent OPN group), post-dilatation alone in 63.2 % of lesions (Post-stent OPN group), and in both situations in 8.3 % of lesions with procedural success in 98.5 % of patients. Further dilatation with different NC balloons was required in both groups (30 %). The median (IQR) OPN balloon diameter in the pre- and post-stent OPN group were 2.5 (2.5, 3.0) and 3.0 (3.0,3.0) mm (p = 0.001), respectively. The difference between the diameter of the stent and OPN balloon used in pre-stent OPN group was 0.5 (0.2, 0.5) mm while it was 0.0 (0.0,0.2) mm in the post-stent OPN group (p < 0.001). Eight complications and two deaths occured. Distal shaft rupture was also noticed. ConclusionOPN balloon is safe, and effective in treating calcified coronary lesions. We propose to undersize the balloon by 0.5 mm for pre-dilatation followed by 0.25 mm larger NC balloon if needed. In the post-dilatation group, use a 1:1 size balloon in a non-tortuous straight segment. Use imaging especially when (1) the pressure taken more than the rated burst pressure, (2) an OPN balloon size is ≥3 mm (3) using 1:1 size OPN balloon in a tortuous segment.

Patient-specific finite element simulation of peripheral artery percutaneous transluminal angioplasty to evaluate the procedure outcome without stent implantation.

The purpose of this work is to present a patient-specific (PS) modeling approach for simulating percutaneous transluminal angioplasty (PTA) endovascular treatment and assessing the balloon sizing influence on short-term outcomes in peripheral arteries, i.e. without stent implantation. Two 3D PS stenosed femoral artery models, one with a dominant calcified atherosclerosis while the other with a lipidic plaque, were generated from pre-operative computed tomography angiography images. Elastoplastic constitutive laws were implemented within the plaque and artery models. Implicit finite element method (FEM) was used to simulate the balloon inflation and deflation for different sizings. Besides vessel strains, results were mainly evaluated in terms of the elastic recoil ratio (ERR) and lumen gain ratio (LGR) attained immediately after PTA. Higher LGR values were shown within the stenosed region of the lipidic patient. Simulated results also showed a direct and quantified correlation between balloon sizing and LGR and ERR for both patients after PTA, with a more significant influence on the lumen gain. The max principal strain values in the outer arterial wall increased at higher balloon sizes during inflation as well, with higher rates of increase when the plaque was calcified. Results show that our model could serve in finding a compromise for each stenosis type: maximizing the achieved lumen gain after PTA, but at the same time without damaging the arterial tissue. The proposed methodology can serve as a step toward a clinical decision support system to improve angioplasty balloon sizing selection prior to the surgery.

Balloon Rupture during Pre-Dilation for Transcatheter Aortic Valve Replacement in Patients with a Bicuspid Aortic Valve: Classification, Treatment Strategies, and Prevention

Balloon rupture during transcatheter aortic valve replacement (TAVR) is a rare but serious complication. Here, we present two cases of balloon rupture in patients with severe aortic stenosis and type 0 bicuspid aortic valves. Three-dimensional models based on pre-procedure cardiac CT angiography were used to investigate these cases post hoc. The models revealed asymmetrical distribution of calcifications with sharply spiked features in the bicuspid aortic valves. The narrow calcified orifices resulted in uneven force distribution on the expanded balloon, thus leading to balloon rupture. We additionally review the classification and causes of balloon rupture, summarize methods for avoiding complications, and describe treatment options. Accurate pre-procedural anatomy evaluation and computer modeling are crucial for planning and managing TAVR procedures. Further investigation through computer simulation is necessary to determine the appropriate balloon size and inflation locations, to provide a reference for pre-procedural preparation.

Clinical outcome of endoscopic balloon dilatations employed in benign paediatric oesophageal pathologies.

Oesophageal dilatations can be done either by bougies or balloons for differing aetiologies in children. We investigated the efficacy and safety of endoscopic balloon dilatations (EBDs) employed by a single surgeon. Relevant data over 12 years were retrospectively evaluated with an ethical committee approval. Ninety-seven children underwent 514 EBD with a median EBD of 3 (1-50). The primary diagnoses were oesophageal atresia (OA) in 51 children, corrosive ingestion in 21, peptic strictures in 13, achalasia in 8 and congenital oesophageal stenosis in 4. The balloon size varied between 3 and 30 mm. The EBD was successfully ended in 72 patients and unsuccessful in six patients. Six children are still under EBD and 13 are lost to follow-up. The overall success rate was 92%. The age at the time of first dilatation was the youngest in OA group followed by corrosive strictures. The balloon sizes differed regarding the age of the patients with larger balloons used as the patient age increased. The sizes of the balloons used at the first and the last EBD differed among diagnostic groups. The total number of dilatations or the time interval between the first and the last EBD dilatation did not show a statistically significant difference among groups. The anatomical type of OA or the height of corrosive stricture revealed no significant difference in any of the above parameters. A transmural oesophageal perforation occurred during 2 (0.4%) EBD sessions. EBD is an effective mean in relieving paediatric oesophageal pathologies with a variety of aetiologies and has a low complication rate.

Assessment of atrial septal defects using 3-dimensional transthoracic echocardiography prior to percutaneous device closure: first report from Bangladesh.

Secundum atrial septal defect (ASD) is treated following trans-catheter closure in alternative to surgical treatment. Per-intervention selection of device size with balloon occlusive diameter (BOD) often cause tearing or enlarging, causing arrhythmias and hypotension. We assessed the suitability of percutaneous device closure for ASD using 3-dimensional transthoracic echocardiography (3DTTE). This study was conducted to investigate if 3DTTE could be an alternative of balloon sizing for selection of device size in atrial septal defect device closure. It was a cross-sectional comparative study. This study was conducted at the department of Pediatric Cardiology, Bangabandhu Sheikh Mujib Medical University for a period of 2 years. Thirty-three purposively selected secundum ASD patients suitable for device closure were included in the study. Ethical permission was taken from the Institutional Review Board and written consent was taken from each patient's guardian. In this study, 3DTTE derived ASD diameter and BOD were compared with that of deployed device size using correlation analysis. Out of 33 patients, 63.6% were female and 36.4% were males had a mean age of 18.07 ± 14.58 years (range 2-55 years). Mean diameter of ASD measured by 2-dimensional (2D) and 3-dimensional (3D) echocardiography were 17.09 ± 6.08 mm and 21.30 ± 6.56 mm, respectively, yielding a significant difference (p < 0.001). 3D echocardiography derived ASDs diameter were highly correlated with device size than BOD and 2D echocardiography derived diameter (2D echocardiography: r = 0.796, p = <0.001, 3D echocardiography: r = 0.960, p = <0.001, BOD: r = 0.840, p = <0.001). 3DTTE can accurately measure ASD diameter and can be used as an alternate, effective, and safe method to select device size.

Endovascular Closure of Secondary Septal Defect in Children with Low Body Weight

The aim. To assess the effectiveness and safety of transcatheter closure of a secondary atrial septal defect (ASD) using an occluder in symptomatic children weighing ≤10 kg.&#x0D; Materials and methods. In the period from November 2014 to June 2021, on the basis of the National Amosov Institute of Cardiovascular Surgery of the National Academy of Medical Sciences of Ukraine, closure of secondary ASD using an occluder was performed in 18 patients, among them 13 women (72.2%) and 5 men (27.8%). Th e mean age of the patients was 18.94±9.44 months (the youngest patient was 12 months, the oldest was 4 years). The mean weight was 9.294±1.170 kg (6.4 kg to 10 kg), the mean Z-score was -1.7±1.5 (-4.6 to 0.46), the mean height was 80 cm (71 cm to 88 cm). According to the measurements by transesophageal echocardiography (TEE), the average size of the defects was 13.7 mm±3.6mm (the largest 18.0 mm, the smallest 6.0 mm).&#x0D; Results and discussion. In our publication, the effectiveness of the method was 100% (18/18), while the world statistics show 94-95%. Th e frequency of complications was 5.6% (n=1). We suggest that this is associated with the use of a sizing balloon and careful selection of the device.&#x0D; When choosing treatment tactics for symptomatic children weighing ≤10 kg, the decisive factor was the determination of the presence of edges and the size of the defect. Defects were considered suitable for closure, according to TEE data, when all margins of the defect were ≥4 mm, except for the aortic margin. Although the total length of the interatrial membrane was taken into account, it was not of decisive importance, since for most occluders with the presence of all edges, the fields of the implant could not interfere with the work of the anatomical structures of the heart. To determine the real size of the defect, we recommend a measuring balloon under TEE control.&#x0D; The following devices were used to close the defect: MemoPart ASD occluder, Amplatzer Septal Occluder, LifeTech HeartR Occluder, LifeTech HeartR Multi-Fenestrated Atrial Septal Defect (MF-ASD) Occluder.&#x0D; &#x0D; Conclusion. After the study, we are convinced that the endovascular method of closing a hemodynamically significant secondary ASD for the treatment of children with a body weight of ≤10 kg has proven to be an effective method, with successful implantation of the occluder in 100% of cases.

Bile Duct Stone Size May Influence the Efficacy of Endoscopic Sphincterotomy With or Without Large-Balloon Dilation: A Meta-Analysis.

Purpose: Endoscopic sphincterotomy (EPT) combined with endoscopic papillary large balloon dilatation (EPBD) are used to remove large common bile duct (CBD) stones. This meta-analysis compared the efficacy and safety of EPT+EPBD versus EPT alone in the removal of stones based on stone size. Materials and Methods: Twenty-two studies (11 randomized control trials [RCTs] and 11 non-RCTs) were identified and reviewed based on searches of Embase, PubMed, and Web of Science. CBD stone's size was measured with reference to diameter of the duodenoscope (13 mm) and size of the large dilatation balloon (17 mm) seen on cholangiogram. The stone clearance rate, required mechanical lithotripsy (ML), procedure time, and pancreatitis were compared according to the mean stone size, and further divided into Groups A (small) 10-13 mm, B (medium) 13-17 mm, and C (large) >17 mm. Results: Subgroup analysis according to CBD stone size showed EPT + EPBD had a significantly better initial stone clearance rate than EPT in Groups B (odds ratio [OR] = 2.39, 95% confidence interval [CI]: 1.20-4.77) and C (OR = 3.05, 95% CI: 1.86-5.03), but not for Group A (OR = 1.41, 95% CI: 0.90-2.21). EPT+EPBD also required significantly less ML than EPT in Groups B (OR = 0.34, 95% CI: 0.15-0.77) and C (OR = 0.31, 95% CI: 0.13-0.73). EPT+EPBD had significantly shorter procedure time than EPT in Group B (standardized mean difference = -1.20, 95% CI: -2.08 to 0.32). In meta-regression analysis, Group B had a better OR in initial stone clearance rate and less ML usage rate correlation with the size of CBD stone, but not for Group C with larger stones. Conclusions: EPT+EPBD had a significantly better initial stone clearance rate, and required less ML with shorter procedure time than EPT for removing medium-sized CBD stones, but the efficacy was limited to large CBD stones. The study protocol and trial registration had been registered in PROSPERO (Registration No. CRD42020171689).

An endoluminal cylindrical sectored-ring ultrasound phased-array applicator for minimally-invasive therapeutic ultrasound.

The size of catheter-based ultrasound devices for delivering ultrasound energy to deep-seated tumors is constrained by the access pathway which limits their therapeutic capabilities. To devise and investigate a deployable applicator suitable for minimally-invasive delivery of therapeutic ultrasound, consisting of a 2D cylindrical sectored-ring ultrasound phased array, integrated within an expandable paraboloid-shaped balloon-based reflector. The balloon can be collapsed for compact delivery and expanded close to the target position to mimic a larger-diameter concentric-ring sector-vortex array for enhanced dynamic control of focal depth and volume. Acoustic and biothermal simulations were employed in 3D generalized homogeneous and patient-specific heterogeneous models, for three-phased array transducers with 32, 64, and 128 elements, composed of sectored 4, 8, and 16 tubular ring transducers, respectively. The applicator performance was characterized as a function of array configuration, focal depth, phasing modes, and balloon reflector geometry. A 16-element proof-of-concept phased array applicator assembly, consisting of four tubular transducers each divided into four sectors, was fabricated, and characterized with hydrophone measurements along and across the axis, and ablations in ex vivo tissue. Simulation results indicated that transducer arrays (1.5 MHz, 9mm OD × 20mm long), balloon sizes (41-50 mm expanded diameter, 20-60 mm focal depth), phasing mode (0-4) and sonication duration (30s) can produce spatially localized acoustic intensity focal patterns (focal length: 3-22 mm, focal width: 0.7-8.7 mm) and ablative thermal lesions (width: 2.7-16 mm, length: 6-46 mm) in pancreatic tissue across a 10-90 mm focal depth range. Patient-specific studies indicated that 0.1, 0.46, and 1.2cm3 volume of tumor can be ablated in the body of the pancreas for 120s sonications using a single axial focus (Mode 0), or four, and eight simultaneous foci in a toroidal pattern (Mode 2 and 4, respectively). Hydrophone measurements demonstrated good agreement with simulation. Experiments in which chicken meat was thermally ablated indicated that volumetric ablation can be produced using single or multiple foci. The results of this study demonstrated the feasibility of a novel compact ultrasound applicator design capable of focusing, deep penetration, electronic steering, and volumetric thermal ablation. The proposed applicator can be used for compact endoluminal or laparoscopic delivery of localized ultrasound energy to deep-seated targets.

Balloon Atrial Septostomy: Does the Balloon Size Matter?

Dextro-transposition of the great arteries is a congenital heart defect with eventually lethal life-threatening consequences of hypoxic low cardiac output. When a balloon atrial septostomy (BAS) is needed, it is performed shortly after birth to create an interatrial shunt and improve systemic blood oxygenation and haemodynamic conditions. In 2019 and 2020, the withdrawal of some balloon atrioseptostomy catheters from the market led to increased use of catheters with different materials, shapes, and sizes. The main objective of this study was to investigate whether the size of the Miller and Fogarty balloon (Edwards Lifesciences) in its 2 variations, the 4.0 cc and the 1.8 cc, had a different impact on the systemic oxygen saturation, on the atrial septal defect (ASD) size, or on the type and frequency of procedure-related complications. We conducted a retrospective study on 134 consecutive patients diagnosed with dextrotransposition of the great arteries between 2002 and 2018 who underwent BAS in a tertiary paediatric hospital in Canada. BAS resulted in a significant increase in oxygen saturation of 18.91% ± 12.95% points (P < 0.0001) and a significant increase in the resulting ASD by 3.92 ± 1.58 mm (P < 0.0001). There was no significant difference in resulting oxygen saturation (P= 0.8370) or the final ASD size (P= 0.2193) based on the balloon size. Severe or life-threatening complications were rare (1%) with no subsequent patient demise. This is the first study to show that the small balloon is as efficient as the large balloon catheter including in premature patients. This raises the question whether different balloon sizes are necessary.

Relationship of Balloon Size in Pulmonary Valvuloplasty Outcome

Objective: To evaluate the relation between balloon size and outcome of patients undergoing pulmonary valvuloplasty. Study Design: A quasi-experimental study. Place and Duration: Pediatric Cardiology Department of Chaudhary Pervaiz Elahi Institute of Cardiology, Multan, Pakistan from January 2021 to June 2022. Methodology: Children of both genders aged less than 15 years having severe pulmonary stenosis and who underwent pulmonary valvuloplasty during the study period were analyzed. After 24 hours post procedure, echocardiography was done to see echo gradient across pulmonary valve, tricuspid regurgitation, pulmonary regurgitation, right ventricular dysfunction or pericardial effusion. Procedure was considered successful if the residual gradient across pulmonary valve was &lt; 40 mmHg, pulmonary regurgitation &lt; moderate and patients had no major complications. Results: In a total of 75 children, 42 (56.3%) were male. The mean age was 6.24 ± 4.81 years. Cyanosis was observed in 10 (13.3%) children while there was right ventricular dysfunction in 6 (8.0%) children. The pulmonary valvuloplasty procedure was successful in 53 (70.6%) cases while in remaining 22 (29.4%) cases, the procedure was partially successful because of infundibular obstruction. We observed that the degree of pulmonary regurgitation was greater when annulus- balloon ratio was 1.3 or more than that (p&lt;0.0001). Practical Implications: Large balloons do not impart advantages beyond that produced by balloons between 1.2-1.4 times of the annular size but further research is required to ascertain these findings Conclusion: Signification relation exists regarding balloon size and outcome of children undergoing pulmonary valvuloplasty as the degree of pulmonary regurgitation was greater when annulus- balloon ratio was 1.3 or more. Keywords: Cyanosis, pulmonary regurgitation, pulmonary valvuloplasty, right ventricular dysfunction.