In this paper, a preliminary stress/strain analysis of the design structure of a nickel-titanium alloy patent foramen ovale occluder is conducted with the finite element simulation analysis method. In the analysis, solid structure modeling is carried out on three different specifications of domestic patent foramen ovale occluders. Referring to the test method of fatigue performance in inspection standard YY/T 1553-2017, an initial installation deformation is applied to the model, and then the fatigue displacement of 2 mm is applied to the sample to make the model fatigue deformation. The fatigue safety factors of each type of occluder are obtained by strain simulation analysis. The results indicate that the minimum fatigue safety factors of the three specifications of domestic patent foramen ovale occluders are 2.09, 2.35 and 2.06 respectively, which all meet the design of fatigue safety factor greater than 1. Among them, 1818 and 3030 specifications of patent foramen ovale occluders have close values in minimum fatigue safety factors, and both are lower than that of 1825 model. Therefore, it is recommended to carry out physical fatigue tests on both 1818 and 3030 specifications to further verify the fatigue performance of the products.
Finite Element Analysis ; Titanium ; Nickel ; Alloys ; Foramen Ovale, Patent ; Materials Testing ; Septal Occluder Device ; Stress, Mechanical

Humans ; Cardiac Catheterization ; Treatment Outcome ; Heart Septal Defects, Atrial/surgery* ; Cerebral Infarction ; Septal Occluder Device

Humans ; Aortopulmonary Septal Defect/surgery* ; Septal Occluder Device

Humans ; Aortopulmonary Septal Defect/surgery* ; Septal Occluder Device

Objective: To assess the safety and efficacy of transcatheter fenestration closure following Fontan procedure with an atrial septal occluder. Methods: This is a retrospective study. The study sample consists of all consecutive patients who underwent closure of a fenestrated Fontan baffle at Shanghai Children's Medical Center Affiliated to Shanghai Jiaotong University School of Medicine between June 2002 and December 2019. The indications of Fontan fenestration closure included that normal ventricular function, targeted drugs for pulmonary hypertension and positive inotropic drugs were not required prior the procedure; and the Fontan circuit pressure was less than 16 mmHg (1 mmHg=0.133 kPa) and no more than a 2 mmHg increase during test occlusion of the fenestration. Electrocardiogram and echocardiography were reviewed at 24 hours, 1, 3, 6 months and annually thereafter post procedure. Follow-up information including clinical events and complications related to Fontan procedure was recorded. Results: A total of 11 patients, including 6 males and 5 females, aged (8.9±3.7) years old were included. The types of Fontan were extracardiac conduits (7 cases) and intra-atrial duct (4 cases). The interval between percutaneous fenestration closure and the Fontan procedure was (5.1±2.9) years. One patient reported recurrent headache after Fontan procedure. Successful fenestration occlusion with atrial septal occluder was achieved in all patients. Compared with prior closure, Fontan circuit pressure ((12.72±1.90) mmHg vs. (12.36±1.63) mmHg, P<0.05), and aortic oxygen saturation ((95.11±3.11)% vs. (86.35±7.26)%, P<0.01) were increased. There were no procedural complications. At a median follow-up of (3.8±1.2) years, there was no residual leak and evidence of stenosis within the Fontan circuit in all patient. No complication was observed during follow-up. One patient with preoperative headache did not have recurrent headache after closure. Conclusions: If the Fontan pressure is acceptable by test occlusion during the catheterization procedure, Fontan fenestration could be occluded with the atrial septum defect device. It is a safe and effective procedure, and could be used for occlusion of Fontan fenestration with varying sizes and morphologies.
Child ; Male ; Female ; Humans ; Child, Preschool ; Septal Occluder Device ; Retrospective Studies ; Atrial Fibrillation ; Cardiac Catheterization/methods* ; China ; Fontan Procedure/methods* ; Treatment Outcome

Objective: To evaluate the feasibility and safety of the LAmbre occluder for large-diameter left atrial appendage occlusion. Methods: This study was a retrospective cohort study. Patients with large orifice of the left atrial appendage (≥31 mm) and occlusion with the LAmbre device in the Arrhythmia Center of Ningbo First Hospital were included from June 2018 to March 2020. Baseline data were collected and major perioperative complications of left atrial appendage occlusion (including death, stroke, instrumental embolism, cardiac tamponade, and major bleeding events) were recorded. Patients were followed up 45 days, 6 months and 12 months after surgery. The shunt and device-related thrombosis were recorded by esophageal cardiac ultrasound or pulmonary vein CT, and the occurrence of postoperative thromboembolism, bleeding events, death and other serious adverse events were recorded. Results: The average age and left atrial appendage ostial dimension of 32 patients (37.5% women) included in this research were (70.4±8.4) years old and (34.4±2.9) mm. The LAmbre device was successfully implanted in 31(96.9%) patients. No major complications occurred during the perioperative period. During the 12-month follow-up, pericardial tamponade occurred in 1(3.2%) patient and was recovered after treatment. There was no occluder edge shunt>5 mm in patients followed up by esophageal echocardiography. No significant peri-device leak, device-related thrombus, thromboembolism or death event has occurred. Conclusion: The LAmbre occluder may be feasible and safe for large-diameter left atrial appendage occlusion.
Aged ; Atrial Appendage/surgery* ; Feasibility Studies ; Female ; Humans ; Male ; Middle Aged ; Retrospective Studies ; Septal Occluder Device/adverse effects* ; Stroke/epidemiology* ; Thromboembolism/etiology* ; Thrombosis ; Treatment Outcome

Objective: To investigate the dynamic change of the secundum atrial septal defect (ASD) throughout the cardiac cycle, and assess its impact on occluder selection. Methods: This study retrospectively analyzed 35 patients with ASD who received electrocardiogram-gated coronary CT angiography (CCTA) throughout the cardiac cycle as well as interventional closure therapy in Fuwai Hospital from December 2016 to December 2019. The raw data were reconstructed into 20 phasic images of RR intervals (RRI) ranging from 0 to 95% in an increment of 5% and transmitted to a workstation for postprocessing. For each phase image, CT virtual endoscopy reconstruction technique (CTVE) was used to provide views of ASD. Axial sequence assisted CT volumetric measurement (CTAS) was used to calculate the maximum dimensions in axial planes (D_a) and in superior-inferior direction (D_b). Using a formula for converting circumference to diameter, the equivalent circle dimensions were calculated (D_e, D_e=minor axis+2 (major axis-minor axis)/3). Taking the data of 75% RRI phase, the patients were divided into D_a75%RRI≥D_b75%RRI group and D_a75%RRIb75%RR group. According to the postoperative chest X-ray, the waist diameter of the occluder in the left anterior oblique plain film was measured, and its correction value (CR-POD_laoc) was calculated with the correction formula. Scatter plots of the changes of the mean values of D_a, D_b and D_e with the cardiac cycle were presented. The change and ratio of measured values of D_a and D_e at 35% and 75% RRI was calculated. The ratio of D_e change to D_a change in D_a75%RRI≥D_b75%RRI group and D_a75%RRIb75%RR group was calculated, respectively, and compared between groups. Pearson correlation analysis was used to explore the correlation between CR-POD_laoc and D_e35%RRI and D_e75%RRI. Results: A total of 35 patients, aged (42.7±15.0) years, including 10 males, were included. Among 35 patients, 8 cases were divided into group D_a75%RRI≥D_b75%RRI and 27 cases into group D_a75%RRIb75%RRI. Both D_a and D_b regularly changed at each phase throughout the cardiac cycle. The D_a changed significantly, with a maximum at phase of 35%-45% of RRI, and a minimum between phases of 90% and 0 of RRI. While the D_b showed insignificant changes during phases of 10%-90% RRI, and increased at 0-10% of RRI, then reduced in the remaining phases. The change of D_a was (6.35±2.46) mm, and the ratio of D_a values at 35% and 75% RRI was 0.77±0.08. The change of D_e was (2.28±1.32) mm, and the ratio of D_e at 35% and 75% RRI was 0.93±0.05. The ratio of D_e change to D_a change in the D_a75%RRI≥D_b75%RRI group was 0.67±0.13; while the ratio was 0.34±0.05 in D_a75%RRIb75%RR group, and there was significant difference between the two groups (P=0.02). CR-POD_laoc was positively correlated with D_{e35% RRI} (r=0.99, P<0.001) and D_{e75% RRI} (r=0.98, P<0.001). Conclusions: Most secundum ASDs show oval shape with D_b>D_a. D_b is basically constant while D_a changes significantly during cardiac cycle (10%-90% RRI). Nonetheless, both values peak and maintain the maximum status at end-systolic phase (35%-45% RRI). For patients with huge ASD, occluder selection should be based on the D_e at 35% RRI phase, which is helpful for the successful intervention.
Adult ; Cardiac-Gated Imaging Techniques ; Computed Tomography Angiography ; Coronary Angiography ; Electrocardiography/methods* ; Female ; Heart Septal Defects, Atrial/surgery* ; Humans ; Imaging, Three-Dimensional ; Male ; Middle Aged ; Retrospective Studies ; Septal Occluder Device

Atrial Appendage/surgery* ; Atrial Fibrillation/surgery* ; Cardiac Catheterization ; Humans ; Septal Occluder Device ; Treatment Outcome

Cardiac Catheterization ; Foramen Ovale, Patent/diagnostic imaging* ; Humans ; Septal Occluder Device ; Stroke

BACKGROUND: Nitinol-containing devices are widely used in clinical practice. However, there are concerns about nickel release after nitinol-containing device implantation. This study aimed to compare the efficacy and safety of a parylene-coated occluder vs. a traditional nitinol-containing device for atrial septal defect (ASD). METHODS: One-hundred-and-eight patients with ASD were prospectively enrolled and randomly assigned to either the trial group to receive a parylene-coated occluder (n = 54) or the control group to receive a traditional occluder (n = 54). The plugging success rate at 6 months after device implantation and the pre- and post-implantation serum nickel levels were compared between the two groups. A non-inferiority design was used to prove that the therapeutic effect of the parylene-coated device was non-inferior to that of the traditional device. The Cochran-Mantel-Haenszel chi-squared test with adjustment for central effects was used for the comparison between groups. RESULTS: At 6 months after implantation, successful ASD closure was achieved in 52 of 53 patients (98.11%) in both the trial and control groups (95% confidence interval (CI): [-4.90, 5.16]) based on per-protocol set analysis. The absolute value of the lower limit of the 95% CI was 4.90%, which was less than the specified non-inferiority margin of 8%. No deaths or severe complications occurred during 6 months of follow-up. The serum nickel levels were significantly increased at 2 weeks and reached the maximum value at 1 month after implantation in the control group (P < 0.05 vs. baseline). In the trial group, there was no significant difference in the serum nickel level before vs. after device implantation (P > 0.05). CONCLUSIONS The efficacy of a parylene-coated ASD occluder is non-inferior to that of a traditional uncoated ASD occluder. The parylene-coated occluder prevents nickel release after device implantation and may be an alternative for ASD, especially in patients with a nickel allergy.
Cardiac Catheterization ; Heart Septal Defects, Atrial/surgery* ; Humans ; Polymers ; Prospective Studies ; Prosthesis Design ; Septal Occluder Device/adverse effects* ; Treatment Outcome ; Xylenes