Study On The Application Paradigm Of CT In Interventional Therapy Of Interventricular Septal Defects In Middle - Aged And Old Patients

Part IValue of Cardiac CT Examination in Adult Patients with Atrial Septal Defect Before Planned Transcatheter ClosuresObjective:To investigate the value of the cardiac CT examination for decision making in adult patients before planned transcatheter atrial septal defect (ASD) closure.Methods:Cardiac CT was performed in 63 adult patients [18 males, aged from 50 to 77 years, mean age (56.87±5.79) years] with ASD before planned transcatheter ASD closure. Coronary CT angiography was made for detection of associated cardiovascular diseases, followed by 3D reconstruction of ASD for determination of the defect size in the GE-workstation, results were compared between transthoracic echocardiography (TTE) measuement, CT measurement, and Atrial septal defect occluder (ASO) waist diameter.Results:Cardiac CT identified additional cardiovascular diseases in 14 patients (23%) and decision making was changed based on cardiac CT results. Coronary artery stenosis was detected in 8 patients by cardiac CT, and proved by coronary angiography, and all of them were given comprehensive management: Percutaneous coronary angioplasty (PTCA) and thanscatheter ASD closure were successively performed in 2 cases, and 1 case with 3 vessel disease was referred to surgery for both coronary artery bypass graft (CABG) and surgical ASD repair, and 5 patients were given pharmacological management for coronary artery disease besides thanscatheter ASD closure. Cardiac CT identified large ASD with insufficient rim tissue in 2 cases and transcatheter closures were abandoned. Cardiac CT screened out 1 case from those with insufficient posterior inferior rim by TTE, and transcatheter ASD closure was successfully performed. Cardiac CT ruled out ASD in 1 patient. In addition, cardiac CT detected 1 partial abnormalous pulmonary vein connection (PAPVC) and 1 ductus arteriosus (PDA) in this cohort. A correlation on ASD measurements was found between CT size and TTE size (r=0.80, P<0.001; Y=0.84X+8.85, R2=0.63, P<0.05) and between ASO size and CT size (r=0.918, P<0.001; Y=0.93X+4.78, R2=0.84, P<0.05)Conclusion:In adult patients with ASD for possible transcatheter closure, cardiac CT is valuable on determing ASD size and morphology and could provide incremental information for optimizing clinical management for ASD patients.Part ⅡAssessment of Atrial Septal Defect Size With Three-dimensional Volumetric Measurement of Cardiac CT:Comparison With Postoperative Occluder Sizing MethodObjective:To evaluate two kinds of practical CT three-dimensional volumetric measurement techniques of sizing atrial septal defects (ASDs) for transcatheter device closure.Methods:Retrospective assessment of 50 consecutive patients who underwent ASD closure. Cardiac CT was performed in them before planned transcatheter ASD closure and postoperative chest radiograph was performed in both posteroanterior and lateral view. Coronary CT angiography was made for detection of coronary artery disease, followed by three-dimensional reconstruction of ASD for determination of the defect size in the GE-workstation. two kinds of practical CT three-dimensional volumetric measurement techniques of sizing atrial septal defects, one named CT virtual endoscopy assisted volumetric measurement (CTVE) and another called axial sequence assisted volumetric measurement (CTAS), were used for calculating the major axis and the minor axis of the ASD respectively. Thus, we derived the dimensions of the Equivalent Circle whose circumference and area are equal to the elliptic ASD according to the formulation The ASDs occluder (ASO) dimension was measured in the lateral chest radiograph, and this postoperative occluder-waist size (POS) value was regarded as the gold standard for the measurement of ASD. The results were compared between CTVE and CTAS, and the correlation were evaluated between the both and the gold standard.Results:The differences in the major dimensions (-9.05 mm, t=-6.60, P <0.05), minor dimensions (-4.86 mm, t=-4.39, P<0.05) and Equivalent circle dimensions (-7.65 mm, t=-6.40, P<0.05) of ASD between CTAS and CTVE were statistically significant. Though the CTAS cannot provide the en face views of ASDs, the Equivalent Circle dimensions measured by CTAS (22.48±5.59) mm was correlated well with POS (27.07±6.83) mm (Y=1.14X+1.39, r=0.94, P<0.01), and A good correlation was found between this Equivalent Circle dimensions and ASO size, (Y=1.02X+6.84 (R2=0.78, r=0.88, P<0.05), the correlation between the Equivalent Circle dimensions measured by using CTVE(30.13±9.27) mm and POS was poor, (Y=0.30X+17.94, r=0.41, P<0.01), while it can provide the en face views of ASDs.Conclusion:CTVE and CTAS are two complementary techniques of assessment ASDs for transcatheter device closure.Part IIIPercutaneous Closure of Atrial Septal Defect in Adult:Comprehensive Evaluation by TTE, TEE and CTAObjective:To investigate the accuracy of cardiac CT angiograph in assessment of atrial septal defect and its value for decision making in adult patients before planned percutaneous transcatheter closure.Methods:Sixty-three adult patients [16 males,47 females, aged from 50 to 77 years, mean age (56.41±5.64) years] who underwent successful transcatheter closure of ASD-II (50) or surgery (13)were enrolled in this study. Transthoracic echocardiography (TTE) and Transesophageal echocardiography (TEE) were performed to select suitable cases for device closure, and followed by Coronary CT angiography examination for detection of associated cardiovascular diseases. Defect size and rim tissue were measured on ASD three-dimensional (3D) reconstruction imaging sections obtained in the GE-workstation, and CT axial sequence assisted volumetric measurement (CTAS) were used for calculating the major axis and the minor axis of the ASD respectively; in the same way, the ASD rims and the atrial septal length(ASL)were measured. Paired Samples Test and correlation was calculated between CTA measurement TTE., TEE and post-procedural occluder size(POS).Results:For ASD size, mean differences were 4.48 mm (3.28-5.76)s 1.98 mm (0.94-3.03mm)、and -3.66mm(-2.97 and -4.34mm)compared CTA imaging with TTE. TEE and POS; A better correlation on ASD measurements was found between CT size and TTE、TEE, and POS, the strongest correlation was found between CT size and POS(Y=1.10X+1.33, R2=0.88, P<0.05);for defect rims and septal length, there were no significant differences between the measurements at CTA imaging and TEE or surgical results except for IVC rim, IVC rim length was overestimated at TEE versus CTA imaging (mean difference 2.2mm(3.08-1.35), Rim distance to mitral valve and coronary sinus was easy to assess; Additional information were identified in 15 patients (27%) by Cardiac CT and TEE which resulted of the clinical management alteration, Specifically,13 case was referred to surgery for serious coronary artery disease(1 cases), superior sinus venous ASD(3 cases), insufficient posterior inferior rim (8 cases) and vegetation in pulmonary artery (1 case). Among the other 50 patients, percutaneous coronary angioplasty (PTCA) and thanscatheter ASD closure were one-stop done in 2 cases.Conclusion; In adult patients with ASD for possible transcatheter closure, cardiac CT can enable determination of defect size, rim distances to adjacent structures, and provide incremental information to optimize clinical management.Part IVPreliminary Application of Equivalent Circle Conversion in Selection of Atrial Septal Defect OccluderObjective:To compare Equivalent Circle Dimension (ECD) with atrial septal defect major dimension and gold standard, and assess the use of the Equivalent Circle Conversion in selection of atrial septal defect occluder.Methods:Prospective assessment of 96 consecutive patients who underwent ASD closure successfully. Cardiac CT was performed before planned transcatheter ASD closure for detection of coronary artery disease, followed by 3D reconstruction of ASD for determination of the defect size in the GE-workstation, and axial sequence assisted volumetric measurement (CTAS) were used for calculating the major axis a (ASDa, a)and the minor axis b(ASDb, b)of the ASD respectively. Thus, we derived the dimensions of the Equivalent Circle that circumference and area are equal to the elliptic ASD according to the formulation (D=(?)). The Atrial septal defect occlude (ASO) was chosen on the basis of the formula of Y(ASO)=1.03X(ECDz)-0.45±1mm. Postoperative chest radiograph was performed in both posteroanterior and lateral view, the ASDs occluder dimension was measured in the lateral chest radiograph, and this postoperative occluder-waist size(POS) value was regarded as the gold standard for the measurement of ASD. Then the other forms of Equivalent Circle Conversion were performed according to the Equal-area conversion formulation ECDs=(?), the Equal-circumference conversion formulation ECDc=b+2(a-b)/π,And its Simplified form ECDcs= b+2(a-b)/3 respectively. To compare ASDa and the ECD with ASO size for screening out the cases whose ASDa or ECD is larger than ASO size, and X2 Tests were performed; then to compare ECD and POS, and the correlation were evaluated between the ECD and POS.Results:the ASDa were larger than ASO size in 8 cases, and the ECDz was larger than ASO size in 1 case, no case with larger ECDs and ECDc, Fisher’ Exact Test shows the significant difference(p=0.007). to Compared with POS, the biggest standard deviation of 2.29mm occurred in ECDz, and the least of 2.05mm occurred in ECDc; the correlation between ECDz and POS was excellent(Y=1.10X+2.42, R2=0.89, P<0.05), and the correlation between ASDa and POS was similar to it (Y=0.98X+2.54; R2=0.89, P<0.05), the strongest correlation was found between ECDc and POS(Y=1.06X+2.38, R2=0.91, P<0.05).Conclusion:Equivalent Circle Conversion can overcome the limitation of ASD major dimension as a tool of selection ASO, and the ECDc can be an optimal alternative approach for its better correlation with conference standard.Part VIndividual Contrast Medium Ejection Protocol for Coronary CT Angiography With Atrial Septal Defect PatientsPurpose:to determine the individual protocol for Dual-source CT contrast-enhanced cardiac imaging for better visualization of both coronary artery and atrial septal defect.Materials and Methods:A total of ninety consecutive patients were included in this prospective study. Each 30 patients were assigned to use a different contrast protocol:group I:monophasic protocol (contrast injection without saline chaser) with a single-syringe injector; group Ⅱ:biphasic protocol (contrast injection+saline chaser) with a dual-syringe injector; group III:triphasic protocol (contrast media+30 mL of 70%:30% saline-to-contrast medium mixture+saline chaser) with a dual-syringe injector. Two radiologists rated the visualization of right and left heart structures, coronary artery, ASD (atrial septal defect). One observer performed attenuation measurements of the cardiac chambers and the coronary arteries. Data were analyzed with one-way analysis of variance and LSD post-hoc multiple comparison procedures.Results:Data for 33 men and 57 women (mean age,58 years) were included, the groups were comparable in mean age, body weight and heart rate. Among the three groups, there were no significant differences for the mean medium attenuation of the left heart and the coronary arteries among the three groups (p>0.05), and the 250HU of CT values are met in right ventriculars and pulmonary arteries in all groups, and the delineation of ASD received significantly higher scores (p<0.05 LSD test) in the group 2 than the group 3 for the latter’ s diminished difference in contrast medium concentration between the left and the right atrium. Conclusion:biphasic protocol are superior to the other protocols for reducing the amount of contrast media and improving the delineation of ASD, and it is advisable for coronary CT angiography with Atrial Septal Defect Patients.Part VIAssessment of The Symptomatic Patient After Transcatheter Atrial Septal Defect Closure by Cardiac CTObjective:we sought to evaluate clinic considerations and image findings of Cardiac CT in symptomatic patients after transcatheter atrial septal defect (ASDs) closure.Methods:A total of 53 symptomic patients who underwent CTA with post-transcatheter ASD closure were grouped according to age:Group A consisted of 42 adult and advanced patients(≧40 years), and Group B included 11 younger patients (<40 years).clinical and CTA data analysis included age, gender, symptoms, and CT findings.Results:Among 53 patients (32 were female, mean age 48.52 years, ranged 19-72 years), the common postoperative symptoms for patient presenting hospital with are chest tightness, dyspnea and palpitation, and CTA were considerated to rule out CAD in 37 cases; 9 patients present dyspnea and CTA were considerated to rule out PE; 4 cases underwent CTA to evaluate left atrial and pulmonary vein before RF atrial fibrition, the complications were under consideration in 3 patients with abnormal precordial distress after transcatheter ASD closure. As for CT fingdings, dilatation of the pulmonary artery in varying degrees were noted in all patients, additionally, in group A consisted of 42 patients, coronary artery disease proved by coronary angiography were detected in 9 patients by cardiac CT, in addition, cardiac CT detected 2 cases with anomalous origin of coronary artery,1 partial abnormalous pulmonary vein connection (PAPVC), and 1 case with a residual ASD.In group B with 11 patients,3 cases were noted with abnormal ASO position and shape respectively. Though the significant, the purpose and findings of CTA are both different. Though Positive CT findings did not significantly differ between two groups(P=0.73), the essential abnormalities are absolutely differ.Conclusion:Cardiac symptoms after ASO implant deserve thorough investigation, and cardiac CT is feasible in providing individual anatomic information in symptomatic patients at different ages, especially in patients with clinical questions left unanswered by routine examination.