Outcomes of Surgical Repair of Complex D-Transposition of the Great Arteries.

BACKGROUND: D-transposition of the great arteries (TGA) or TGA-type double outlet right ventricle (DORV) with ventricular septal defect (VSD) and left ventricular outflow tract obstruction (LVOTO) may be treated with the arterial switch operation (ASO), Rastelli, Réparation à l'Etage Ventriculaire (REV), or Nikaidoh procedures. We evaluated midterm results of these techniques. METHODS: We retrospectively reviewed 42 cases of anatomic repair from 2005 to 2014 at our institution for TGA (n = 29) or TGA-type DORV (n = 13) with VSD and LVOTO. We analyzed outcomes (mortality, reoperation, residual/recurrent LVOT peak gradient ≥20 mm Hg, right ventricular outflow tract [RVOT] peak gradient ≥40 mm Hg) and performed a risk analysis. Mean follow-up was 5.77 ± 3.08 years. RESULTS: Seventeen (40.5%) patients had an ASO with (n = 4) or without (n = 13) LVOTO resection. The Rastelli, REV, and Nikaidoh procedures were used in 14 (33%), 5 (12%), and 6 (14%) patients, respectively. There were no mortalities or moderate aortic insufficiency at last follow-up. Three (9%) patients developed LVOT gradient ≥20 mm Hg, while nine (21.4%) patients had RVOT obstruction. Reoperations included RVOT/pulmonary artery reoperation (n = 10; 23.8%) and LVOT reoperation (n = 1; 2.5%). Freedom from reoperation was 84% ± 6% and 75% ± 9% at one and three years, respectively, for the entire cohort with no differences between groups by type of operation (log-rank P = .64). The Nikaidoh procedure compared favorably to all other techniques in terms of reoperation (n = 0/6; 0% vs n = 13/36; 36%; P = .08). CONCLUSIONS: Midterm outcomes after anatomic repair for TGA or TGA-type DORV with LVOTO and VSD are excellent but vary by surgical technique. The Nikaidoh procedure seems to compare favorably to the other techniques.

Patients with anomalous aortic origin of the coronary artery remain at risk after surgical repair.

OBJECTIVES: Anomalous aortic origin of a coronary artery (AAOCA) from the opposite sinus of Valsalva is a rare cardiac anomaly associated with sudden cardiac death (SCD). Single-center studies describe surgical repair as safe, although medium- and long-term effects on symptoms and risk of SCD remain unknown. We sought to describe outcomes of surgical repair of AAOCA. METHODS: We reviewed institutional records for patients who underwent AAOCA repair, from 2001 to 2016, at 2 affiliated institutions. Patients with associated heart disease were excluded. RESULTS: In total, 60 patients underwent AAOCA repair. Half of the patients (n = 30) had an anomalous left coronary artery arising from the right sinus of Valsalva and half had an anomalous right. Median age at surgery was 15.4 years (interquartile range, 11.9-17.9 years; range, 4 months to 68 years). The most common presenting symptoms were chest pain (n = 38; 63%) and shortness of breath (n = 17; 28%); aborted SCD was the presenting symptom in 4 patients (7%). Follow-up data were available for 54 patients (90%) over a median of 1.6 years. Of 53 patients with symptoms at presentation, 34 (64%) had complete resolution postoperatively. Postoperative mild or greater aortic insufficiency was present in 8 patients (17%) and moderate supravalvar aortic stenosis in 1 (2%). One patient required aortic valve replacement for aortic insufficiency. Two patients required reoperation for coronary stenosis at 3 months and 6 years postoperatively. CONCLUSIONS: Surgical repair of AAOCA is generally safe and adverse events are rare. Restenosis, and even sudden cardiac events, can occur and long-term surveillance is critical. Multi-institutional collaboration is vital to identify at-risk subpopulations and refine current recommendations for long-term management.

Significance of Intraoperative Revision During Arterial Switch Operation in the Current Era.

BACKGROUND: Arterial switch operation (ASO) is a relatively safe operation nowadays. We hypothesize that intraoperative revision for coronary malperfusion still plays an important role during ASO in the current era. METHODS: From January 2005 to May 2016, 244 patients underwent ASO. Medical records were reviewed and the details of intraoperative revision were described. Morbidity and mortality were compared in patients with/without intraoperative revision. Factors related to the need for intraoperative revision were analyzed. RESULTS: Seventeen (7%) patients needed intraoperative revision. As a technique for intraoperative revision, revision of a coronary button was performed in eight patients and revision of the main pulmonary artery anastomosis to relieve compression on the coronary artery was performed in five patients. Factors related to intraoperative revision were body weight at surgery ( P = .051), eccentric position of the coronary ostium ( P = .01), single coronary artery system ( P = .03), and intramural coronary artery ( P = .003). The commonest coronary artery origin and branching pattern was not protective against the need for intraoperative revision ( P = .43). Discharge mortality was 2% overall: 2 of 17 with intraoperative revision versus 3 of 238 without it ( P = .04). Patients who underwent intraoperative revision had longer postoperative hospitalization ( P = .003). CONCLUSION: The need for intraoperative revision was related to eccentric coronary ostium, single coronary artery, and intramural coronary artery. Although the need for intraoperative revision correlated with higher mortality and morbidity, prompt intraoperative revision also likely contributed to our good results after ASO.

Radiation dose management for pediatric cardiac computed tomography: a report from the Image Gently 'Have-A-Heart' campaign.

Children with congenital or acquired heart disease can be exposed to relatively high lifetime cumulative doses of ionizing radiation from necessary medical imaging procedures including radiography, fluoroscopic procedures including diagnostic and interventional cardiac catheterizations, electrophysiology examinations, cardiac computed tomography (CT) studies, and nuclear cardiology examinations. Despite the clinical necessity of these imaging studies, the related ionizing radiation exposure could pose an increased lifetime attributable cancer risk. The Image Gently "Have-A-Heart" campaign is promoting the appropriate use of medical imaging studies in children with congenital or acquired heart disease while minimizing radiation exposure. The focus of this manuscript is to provide a comprehensive review of radiation dose management and CT performance in children with congenital or acquired heart disease.

Cardiac-Specific Conversion Factors to Estimate Radiation Effective Dose From Dose-Length Product in Computed Tomography.

OBJECTIVES: This study sought to determine updated conversion factors (k-factors) that would enable accurate estimation of radiation effective dose (ED) for coronary computed tomography angiography (CTA) and calcium scoring performed on 12 contemporary scanner models and current clinical cardiac protocols and to compare these methods to the standard chest k-factor of 0.014 mSv·mGy-1cm-1. BACKGROUND: Accurate estimation of ED from cardiac CT scans is essential to meaningfully compare the benefits and risks of different cardiac imaging strategies and optimize test and protocol selection. Presently, ED from cardiac CT is generally estimated by multiplying a scanner-reported parameter, the dose-length product, by a k-factor which was determined for noncardiac chest CT, using single-slice scanners and a superseded definition of ED. METHODS: Metal-oxide-semiconductor field-effect transistor radiation detectors were positioned in organs of anthropomorphic phantoms, which were scanned using all cardiac protocols, 120 clinical protocols in total, on 12 CT scanners representing the spectrum of scanners from 5 manufacturers (GE, Hitachi, Philips, Siemens, Toshiba). Organ doses were determined for each protocol, and ED was calculated as defined in International Commission on Radiological Protection Publication 103. Effective doses and scanner-reported dose-length products were used to determine k-factors for each scanner model and protocol. RESULTS: k-Factors averaged 0.026 mSv·mGy-1cm-1 (95% confidence interval: 0.0258 to 0.0266) and ranged between 0.020 and 0.035 mSv·mGy-1cm-1. The standard chest k-factor underestimates ED by an average of 46%, ranging from 30% to 60%, depending on scanner, mode, and tube potential. Factors were higher for prospective axial versus retrospective helical scan modes, calcium scoring versus coronary CTA, and higher (100 to 120 kV) versus lower (80 kV) tube potential and varied among scanner models (range of average k-factors: 0.0229 to 0.0277 mSv·mGy-1cm-1). CONCLUSIONS: Cardiac k-factors for all scanners and protocols are considerably higher than the k-factor currently used to estimate ED of cardiac CT studies, suggesting that radiation doses from cardiac CT have been significantly and systematically underestimated. Using cardiac-specific factors can more accurately inform the benefit-risk calculus of cardiac-imaging strategies.

Estimating Effective Dose of Radiation From Pediatric Cardiac CT Angiography Using a 64-MDCT Scanner: New Conversion Factors Relating Dose-Length Product to Effective Dose.

OBJECTIVE: The purpose of this study is to determine the conversion factors that enable accurate estimation of the effective dose (ED) used for cardiac 64-MDCT angiography performed for children. MATERIALS AND METHODS: Anthropomorphic phantoms representative of 1- and 10-year-old children, with 50 metal oxide semiconductor field-effect transistor dosimeters placed in organs, underwent scanning performed using a 64-MDCT scanner with different routine clinical cardiac scan modes and x-ray tube potentials. Organ doses were used to calculate the ED on the basis of weighting factors published in 1991 in International Commission on Radiological Protection (ICRP) publication 60 and in 2007 in ICRP publication 103. The EDs and the scanner-reported dose-length products were used to determine conversion factors for each scan mode. The effect of infant heart rate on the ED and the conversion factors was also assessed. RESULTS: The mean conversion factors calculated using the current definition of ED that appeared in ICRP publication 103 were as follows: 0.099 mSv · mGy-1 · cm-1, for the 1-year-old phantom, and 0.049 mSv · mGy-1 · cm-1, for the 10-year-old phantom. These conversion factors were a mean of 37% higher than the corresponding conversion factors calculated using the older definition of ED that appeared in ICRP publication 60. Varying the heart rate did not influence the ED or the conversion factors. CONCLUSION: Conversion factors determined using the definition of ED in ICRP publication 103 and cardiac, rather than chest, scan coverage suggest that the radiation doses that children receive from cardiac CT performed using a contemporary 64-MDCT scanner are higher than the radiation doses previously reported when older chest conversion factors were used. Additional up-to-date pediatric cardiac CT conversion factors are required for use with other contemporary CT scanners and patients of different age ranges.

Early Complete Atrioventricular Canal Repair Yields Outcomes Equivalent to Late Repair.

BACKGROUND: Repair of complete atrioventricular canal early in infancy has traditionally carried greater morbidity and mortality than repair performed later. However, an individualized anatomy-based repair may give young infants outcomes that are equivalent to older patients. METHODS: We retrospectively reviewed 139 patients who underwent complete atrioventricular canal repair from January 2005 to December 2012. An individualized approach was used: 2-patch repair was performed in 98 patients for large ventricular septal defects and a modified single-patch ("Australian technique") was used in 41 for "shallow" ventricular septal defects. RESULTS: The average age was 25.5 ± 3.9 weeks, 50% were boys, and 78% had trisomy 21. Mean follow-up was 5.1 ± 0.2 years, with 100% completeness of data. There were 3 in-hospital deaths (2.1%) and 1 late death (0.7%). A permanent pacemaker was required in 2 patients (1.4%). The rate for left atrioventricular valve reoperation was 8% at a mean of 211 ± 238 days after the original repair (range, 6 to 682 days). Compared with patients aged older than 3 months, the 39 patients (28%) who were younger than 3 months had similar perioperative courses and rate of reoperation. Compared with patients with an Australian repair, the 98 patients (71%) with a 2-patch repair were more likely to have trisomy 21 and had slightly increased cardiopulmonary bypass and cross-clamp times but similar outcomes. Multivariate analysis showed postoperative left atrioventricular valve regurgitation greater than 2 and left ventricular outflow tract obstruction were significant risk factors for reoperation on the left atrioventricular valve (both p < 0.05). CONCLUSIONS: Repair of complete atrioventricular canal using an individualized surgical approach yields reoperation and early mortality rates similar for younger infants compared with older infants, obviating the need to delay operation in symptomatic patients.

Evaluation of a second-generation microtransesophageal echocardiography transducer and software.

BACKGROUND: Transesophageal echocardiographic imaging of small infants has been limited because of equipment size. A newer miniaturized transducer has allowed for the imaging of even the smallest patients but has been limited by intermittent poor image quality because of hardware durability. A second generation of the transducer was developed to address this problem. The aim of this study was to evaluate the performance and durability of the second-generation transducer over multiple uses and to compare the image quality from the modified transducer and new software preset to the original transducer. METHODS: Patients undergoing transesophageal echocardiography (TEE) based on clinical indications with the original or second-generation transducers were included in the study. All studies were reviewed for image quality and unacceptable image degradation, which was defined as imaging quality inadequate for clinical use. Study review was performed by two echocardiographers. RESULTS: Using the original transducer, 37 studies were performed with a mean patient weight of 3.46±0.89 kg (range 2.1-5.7). Using the second-generation transducer, 65 studies were performed with a mean patient weight of 4.87±2.05 kg (range 2.2-13.8). Image quality was clinically inadequate in 8 of the 35 studies with the original transducer and in zero with the second generation (P<.0001). CONCLUSIONS: The second-generation transducer allows for effective use of TEE even in the smallest infants and avoids the mechanical failures associated with the first-generation release.