Exploration Of Shaping Method Of Transseptal Puncture Needle Based On CT Image Of Oval Fossa And Computer Simulation

Objective:The study aimed to measure and analyze distances between atrial anatomical structures related to cardiac electrophysiology,and shape the atrial septal puncture needle through computer simulation,to assist electrophysiologists to adjust the arc and length of transseptal(TS)puncture needles,thus improving the success rate of transseptal puncture and reducing the risk of radiofrequency ablation.Methods:One hundred and one patients who underwent coronary computed tomography angiography(CTA)or atrial CTA between October 2020 and January 2021 were included.Distances from the ostia of the inferior vena cava(IVC)to different targets on the fossa ovalis(superior,middle,inferior,anterior,and posterior)were measured.Age,sex,and comorbidities were further analyzed in terms of determining or predicting factors.The distances from the inferior vena cava to the coronary sinus(CS)and the right atrial diameter were also measured.Through computer simulation,the arc angle and length of the puncture needle were changed,and four reshaped transseptal puncture needle models were established to evaluate the influence of arc angle and length on the geometry of the transseptal puncture needle assembly.Results:The distance from the IVC to the anterior edge of the 1/2-height of the fossa ovalis(16.29 mm)was greater than to the midpoint(10.02 mm)and the posterior edge(5.85 mm).The distance from the IVC to the midpoint of the 1/2-height of the fossa ovalis(y)increased with increasing distance from the IVC to the midpoint of the 1/2-height of the CS(x),conforming to the relationship y = 0.385 x + 0.548.The distance also increased in correspondence with the anteroposterior and left-right diameter of the right atrium,but did not increase or decrease with the upper-lower diameter of the right atrium.The distance from the IVC to the midpoint of the 1/2-height of the fossa ovalis did not increase or decrease with age and did not vary with sex.The distance was also greater in patients with atrial fibrillation than in normal individuals,and the atrial diameter was greater than in non-AF patients.The increase of the arc angle of the transseptal puncture needle has a greater influence on the change of the arc angle of the puncture needle than the arc length,and with the increase of the arc angle,the puncture needle can reach the fossa ovalis puncture point farther from the inferior vena cava.However,as the arc angle increases,the interaction between the puncture needle and the expander increases,and the risk of embolism may increases.Conclusion:The distances from the IVC to different sites on the FO showed specific regularities,and we can infer the location on the FO from the position of the CS.By reshaping the arc angle of the puncture needle,the transseptal puncture needle can reach the fossa ovails puncture point farther from the inferior vena cava.