Dual-source Computed Tomography for Evaluating Pulmonary Artery and Aorta in Pediatric Patients with Single Ventricle

Role of Computed Tomography Angiography in the Short-Term Follow-up of Aortic Coarctation Repair

INTRODUCTION

Coarctation of the aorta (CoA) is a narrowing of the thoracic aorta that often manifests as discrete stenosis but may be tortuous or in long segment. The study aimed to evaluate pre and post-surgical aspects of pediatric patients submitted to CoA surgical correction and to identify possible predisposing factors for aortic recoarctation.

METHODS

Twenty-five patients were divided into groups according to presence (N=8) or absence (N=17) of recoarctation after surgical correction of CoA and evaluated according to clinical-demographic profile, vascular characteristics via computed angiotomography (CAT), and other pathological conditions.

RESULTS

Majority of males (64%), ≥ 15 days old (76%), ≥ 2.5 kg (80%). There was similarity between groups with and without recoarctation regarding sex (male: 87% vs. 53%; P=0.277), age (≥ 15 days: 62.5 vs. 82%; P=0.505), and weight (≥ 2.5 kg: 87.5 vs. 76.5; P=0,492). Altered values of aortic root/Valsalva diameter, proximal transverse arch, and distal isthmus, and normal values for aorta prevailed in preoperative CAT. Normal values for the aortic root/Valsalva sinus diameter were observed with and without recoarctation, the same for both groups regarding ascending and descending aorta in postoperative CAT. No significant difference for altered values of proximal transverse arch and alteration in distal isthmus was observed.

CONCLUSION

No predictive risk for recoarctation was observed. CTA proved to be important in CoA diagnosis and management, since CoA is mainly related with altered diameter of aortic root/sinus of Valsalva and proximal and distal aortic arch/isthmus, however, it failed to show predictive risk for recoarctation.

How Does Cross-Sectional Imaging Impact the Management of Patients With Single Ventricle After Bidirectional Cavopulmonary Connection?

BACKGROUND

There is currently no consensus regarding the use of surveillance cross-sectional imaging in pediatric patients after bidirectional cavopulmonary connection (BDCPC). We sought to determine how computed tomography with angiography (CTA) and cardiac magnetic resonance (CMR) imaging impacted the clinical management of pediatric patients after BDCPC.

METHODS

A single-center retrospective study including patients with single ventricle who had BDCPC between 2010 and 2019, and CTA/CMR studies obtained in these patients, at ≤5 years of age, and with Glenn physiology. Repeat studies on the same patient were included if the clinical situation had changed. The impact of CTA/CMR studies was categorized as major, minor, or none.

RESULTS

Twenty-four patients (63% male) and 30 imaging studies (22 CTAs) were included. 60% were obtained in patients with hypoplastic left heart syndrome (HLHS); most common indication was Follow-up after an intervention (23%). 6 CMRs were performed on stable HLHS patients as part of a research protocol, with no clinical concerns. The overall impact of CTA/CMR studies was major in 13 cases (43.3%). CTA/CMR studies performed ≥1 year of age (62.5% vs 21.4%, P = .02) and in non-HLHS patients (66.7% vs 27.8%, P = .035) were associated with major impact. Also, 2/6 Research studies were associated with a major impact.

CONCLUSIONS

CTA/CMR imaging in pediatric patients with SV after BDCPC was associated with significant clinical impact in over 40% of cases, with a higher impact if obtained in patients ≥1 year of age and in non-HLHS patients. We cannot disregard the possibility of CMR as a surveillance imaging modality in this population.

Outcomes of bidirectional Glenn surgery done without prior cardiac catheterization

Background

Cardiac catheterization is usually done routinely in patients with univentricular hearts before palliative Bidirectional Glenn (BDG) surgery. The objective of this study was to compare the outcomes of patients with physiological univentricular hearts and restrictive pulmonary flow that did not undergo routine cardiac catheterization before BDG with the patients that did have cardiac catheterization done. We retrospectively reviewed the data of all patients with single ventricle physiology and restrictive pulmonary blood flow who underwent BDG surgery from January 2016 till December 2020. Patients were divided into two groups: the catheterization and the non-catheterization groups.

Results

Out of 93 patients, 25 (27%) underwent BDG surgery without prior cardiac catheterization. The median age of patients was ten months, interquartile range (IQR) was 5–18 months. Tricuspid atresia represented 36% of the non-catheterization group, while unbalanced atrioventricular septal defect and hypoplastic left heart syndrome represented 19% and 17.6% of the catheterization group. No patients in the catheterization group were excluded from further BDG surgery based on the catheterization data. Moreover, no significant differences were found between the patients' groups regarding the length of hospital stay, length of intensive care unit stay, postoperative oxygen saturation, or survival (P = 0.266, P = 0.763, P = 0.543, P = 0456).

Conclusions

Although pre-BDG cardiac catheterization is the routine and standard practice, in certain situations, some patients with single ventricle physiology and restrictive pulmonary blood flow may go directly to BDG without cardiac catheterization if noninvasive imaging is satisfactory on a case-by-case basis and according to center experience. Pre-BDG catheterization could be reserved for patients with limited echocardiographic studies, high-risk patients, or those indicated for catheter intervention before BDG surgery.

Image quality and radiation dose of dual source high pitch computed tomography in pediatric congenital heart disease

To explore the image quality and radiation dose of dual source high-pitch cardiac computed tomography with tailored contrast injection protocols for pediatric congenital heart disease patients (CHD). In total, 27 infants with CHD (median age 109 days [IQR 6-199]) were retrospectively analyzed regarding dose length product (DLP) and effective dose (ED) after undergoing cardiothoracic CT imaging. Scan parameters were adjusted on a dual source/detector CT (DSCT) to minimize radiation dose while maintaining adequate quality. Image acquisition was performed at 70% of the R-R interval. Dose reducing measures included prospective electrocardiogram gating, utilizing slow injection velocities and foregoing bolus tracking during contrast injection. Image quality was assessed for artefacts, vessel definition, and noise on a 5-point scale (1 non-diagnostic, 5 excellent). Series were scored on a 0-to-3-point scale regarding answered clinical questions (0 non-diagnostic, 3 all clinical questions could be answered). The median DLP was 5.2 mGy*cm (IQR 3.5-7.8) leading to a median ED of 0.20 mSv (IQR 0.14-0.30). On average the acquired images scored 13.3 ± 2.1 (SD) out of a maximum 15 points with an intraclass correlation coefficient (ICC) of 0.94. All acquired series were able to fully answer all clinical questions scoring maximum points (ICC 1.0). Dual source high pitch CT protocols combined with custom contrast agent injection protocols in pediatric patients with CHD delivered sufficiently high diagnostic imaging quality combined with low submilisievert radiation doses. Prospective high pitch imaging is a reliable method for depiction of cardiac anatomy even in very young pediatric CHD patients with elevated heart rates.