Long-term results of ventricular septation for double-inlet left ventricle†.

OBJECTIVES: To review the long-term surgical outcomes of ventricular septation for double-inlet left ventricle and reconsider the possibility of ventricular septation as an option of surgical treatments. METHODS: Between 1978 and 1994, 22 patients with double-inlet left ventricle underwent ventricular septation. The mean age at operation was 5.3 years (range 0-22 years). Follow-up was carried out in 20 of 22 patients (91%) and the mean follow-up period was 14.7 years (range 0-39 years). RESULTS: Actuarial survival and reoperation-free survival rates at 30 years were 49% and 21%, respectively. To date, 8 patients have been followed up. Among them, atrioventricular valve replacement and permanent pacemaker were required in 4 and 7 patients, respectively. Late cardiac catheter examination at 25.5 years after surgery showed that the median cardiac index was 2.6 l/min/m2 (range 2.1-3.4 l/min/m2), left ventricular end-diastolic pressure was 7 mmHg (range 4-11 mmHg), left ventricular ejection fraction was 50% (range 27-63%), right ventricular ejection fraction was 53% (range 31-66%) and central venous pressure was 6 mmHg (range 4-11 mmHg). At the latest follow-up, the New York Heart Association Functional Classification was I for 5 patients, II for 2 patients and III for 1 patient. The median peak oxygen uptake was 52.9% (range 44.1-93.5%). CONCLUSIONS: Some patients with double-inlet left ventricle were able to maintain low central venous pressure and a sufficient cardiac index long after ventricular septation. Although the single ventricle strategy remains a first-line treatment, ventricular septation can be a surgical treatment option.

Utility of a super-flexible three-dimensional printed heart model in congenital heart surgery.

OBJECTIVES: The objective of this study was to assess the utility of 3D printed heart models of congenital heart disease for preoperative surgical simulation. METHODS: Twenty patient-specific 3D models were created between March 2015 and August 2017. All operations were performed by a young consultant surgeon who had no prior experience with complex biventricular repair. All 15 patients with balanced ventricles had outflow tract malformations (double-outlet right ventricle in 7 patients, congenitally corrected transposition of great arteries in 5, transposition of great arteries in 1, interrupted aortic arch Type B in 1, tetralogy of Fallot with pulmonary atresia and major aortopulmonary collateral arteries in 1). One patient had hypoplastic left heart complex, and the remaining 4 patients had a functional single ventricle. The median age at operation was 1.4 (range 0.1-5.9) years. Based on a multislice computed tomography data set, the 3D models were made of polyurethane resins using stereolithography as the printing technology and vacuum casting as the manufacturing method. RESULTS: All but 4 patients with a functional single ventricle underwent complete biventricular repair. The median cardiopulmonary bypass time and aortic cross-clamp time were 345 (110-570) min and 114 (35-293) min, respectively. During the median follow-up period of 1.3 (0.1-2.5) years, no mortality was observed. None of the patients experienced surgical heart block or systemic ventricular outflow tract obstruction. CONCLUSIONS: Three-dimensional printed heart models showed potential utility, especially in understanding the relationship between intraventricular communications and great vessels, as well as in simulation for creating intracardiac pathways.

Optimal target vessel selection for composite and sequential radial artery grafting with an in situ internal thoracic artery.

OBJECTIVES: We retrospectively evaluated graft patency in patients who underwent no-touch aortic arterial off-pump coronary artery bypass grafting to determine the optimal selection of target vessels for improved graft patency of composite and sequential radial artery I-grafts. METHODS: The radial artery was anastomosed to the end of an in situ internal thoracic artery and was sequentially anastomosed to non-left anterior descending arteries. This composite graft was defined as an "I-graft." We evaluated 145 I-grafts with 2, 3, or 4 sequential anastomoses (437 graft segments). A graft segment with the final distal anastomosis of every I-graft was defined as the last graft segment (LGS). When a sequential anastomosis was initiated from the left coronary branch, the I-graft assumed a clockwise course (69.0%). When a sequential anastomosis was initiated from the right coronary branch, the I-graft assumed a counterclockwise course (31.0%). RESULTS: On multivariable analysis, right coronary branch (P < 0.001), moderately stenotic (50-75%) target vessel (P = 0.004), and LGS with moderately stenotic target vessel (P = 0.005) were predictors of mid-term graft occlusion. In situations where the LGS was anastomosed to a severely stenotic target vessel (>75%) with a clockwise course, when the number of moderately stenotic target vessels among sequential graft segments was 0, 1, or ≥2, the mid-term graft patency rates of I-grafts were 94.0%, 86.0%, and 81.4%, respectively. CONCLUSIONS: The selection of target vessels for severely stenotic lesions among sequential graft segments and the clockwise course enhance the mid-term graft patency of sequential radial I-grafts.

Asian consortium on radiation dose of pediatric cardiac CT (ASCI-REDCARD).

BACKGROUND: With incremental utilization of pediatric cardiac CT in congenital heart disease, it is imperative to define its current radiation dose levels in clinical practice in order to help imagers optimize CT protocols, particularly in Asia and other developing countries where CT physicists are not readily available. OBJECTIVE: To evaluate current radiation dose levels and influencing factors in cardiac CT in children with congenital heart disease in Asia by conducting a retrospective multi-center, multi-vendor study. MATERIALS AND METHODS: We included 1,043 pediatric cardiac CT examinations performed in 8 centers between January 2014 and December 2014 to evaluate congenital heart disease. In five weight groups, we calculated radiation dose metrics including volume CT dose index, size-specific dose estimate, dose-length product and effective dose. Age at CT exam, gender, tube voltage, scan mode, CT indication and image reconstruction algorithm were analyzed to learn whether they influenced CT radiation dose. RESULTS: Volume CT dose index, size-specific dose estimate, dose-length product and effective dose of pediatric cardiac CT showed variations in the range of 4.3-23.8 mGy, 4.9-17.6 mGy, 55.8-501.3 mGy∙cm and 1.5-3.2 mSv, respectively, within five weight groups. Gender, tube voltage, scan mode and cardiac function assessment significantly influenced CT radiation dose. CONCLUSION: This multi-center, multi-vendor study demonstrated variations in radiation dose metrics of pediatric cardiac CT reflecting current practice in Asia. Gender, tube voltage, scan mode and cardiac function assessment should be considered as essential radiation dose-influencing factors in developing optimal pediatric cardiac CT protocols.

Late Wall Thickening and Calcification in Patients After Kawasaki Disease.

OBJECTIVES: To evaluate the relationship between the initial diameters of the coronary arteries immediately after the onset of Kawasaki disease (KD) and late increased coronary wall thickening/coronary artery calcification (CAC). STUDY DESIGN: Sixty-five patients (50 males and 15 females) who had undergone selective coronary angiography (CAG) <100 days after the onset of KD were studied late in disease by dual-source computed tomography (DSCT). The maximum diameters of each segment were measured in the initial CAGs, and the relationship between the maximum diameters and the appearance of increased wall thickening/CAC was analyzed. The study cohort was divided into 2 groups: the branches group (BG) and bifurcation at the left coronary artery (LCA) group. The cutoff point of acute coronary artery dilatation for increased wall thickening/CAC was calculated for each group. Risk factors for the appearance of CAC in each group were investigated, as was the sex difference related to the prevalence of CAC in coronary artery lesions (CALs) of the initial CAGs. RESULTS: The cutoff points of acute coronary dilatation for increased wall thickening were 4.8 mm in the BG (n = 344; area under the curve [AUC], 0.89; P < .001) and 5.3 mm in the LCA group (n = 65; AUC, 0.87; P < .001). The interval from the onset of KD (P < .0001) and sex (P = .0084) were also related to the appearance of CAC in the BG. CONCLUSION: Acute coronary dilatation of exceeding ~5.0 mm can lead to late abnormalities of the coronary artery wall. The prevalence of CAC increases with age. There was a sex-based difference in the late incidence of CAC in the CALs.

Radiation-Dose-Lowering Effects of Landiolol Hydrochloride in Coronary Angiography Using Computed Tomography (DELIGHT)　- A Prospective Multicenter Study.

BACKGROUND: Controlling and decreasing the heart rate (HR) of patients during coronary computed tomography angiography (CCTA) is necessary to reduce radiation exposure and improve image quality. This prospective multicenter study aimed to investigate whether HR control with landiolol hydrochloride is useful for reducing radiation exposure during CCTA. METHODS AND RESULTS: We investigated 219 patients with suspected ischemic heart disease whose pretest HRs were 50-80 beats/min. We measured the HR before and after administration of landiolol hydrochloride and compared the estimated exposure inferred from the HR before administration of landiolol hydrochloride with the actual dose. After administration of landiolol hydrochloride, the mean HR (59.9±6.4 beats/min) at the time of CCTA was significantly lower than before administration (69.3±7.3 beats/min; P<0.001); 80% of the patients had controlled HRs at ≤65 beats/min. HR and blood pressure of all the patients recovered after the scan. The mean radiation dose in all patients was approximately 50% derived from the inferred dose before use of landiolol hydrochloride (4.5±3.2 vs. 9.0±3.7 mSv; P<0.001). There were no adverse events during this study. CONCLUSIONS: The use of landiolol hydrochloride during CCTA was safe and resulted in approximately 50% decrease in radiation exposure dose, suggesting the clinical usefulness of this drug. (Circ J 2016; 80: 1225-1231).

Measurements of Coronary Artery Aneurysms Due to Kawasaki Disease by Dual-Source Computed Tomography (DSCT).

Diameters of coronary artery aneurysms (CAAs) complicating acute phase KD can strongly predict the long-term prognosis of coronary artery lesions (CAL). Recently, computed tomographic angiography (CTA) has been used to detect CAL, and the purpose of this study was to determine whether coronary artery diameters measurements by CTA using dual-source computed tomography (DSCT) can be used instead of coronary angiogram (CAG) measurements. Twenty-five patients (22 males and three females) with CAL due to KD, who had undergone both CTA and CAG within one year, were retrospectively evaluated between 2007 and 2013. A prospective electrocardiogram-triggered CTA was performed on a DSCT (SOMATOM(®) Definition, Siemens Healthcare, Germany). Two pediatric cardiologists independently measured the diameters of CAAs twice in each maximum intensity projection (MIP), curved multiplaner reconstruction (MPR) and CAG. We measured 161 segments in total (segment 1-3, 5-7, 11, 13). Diagnostic accuracy was expressed as κ coefficient. A Bland-Altman analysis was also used to assess the intra-observer, inter-observer and inter-modality agreement. The diagnostic quality of CTA was excellent (κ = 0.93). Excellent inter-observer agreement for the diameters of CAAs was obtained for MIP, MPR and CAG and for the intra-observer agreement. The inter-modality agreement was also excellent in measurements of CAA (MPR-CAG: y = 0.9x + 0.40, r = 0.97, p < 0.0001 MIP-CAG: y = x + 0.1, r = 0.94, p < 0.0001). These values in normal coronary arteries were also obtained. We found a significant correlation between CTA and CAG in measuring the coronary arteries. We conclude that measuring coronary artery diameters by CTA is reliable and useful.

[Role of cardiac computed tomography in cardiac surgery].

In the field of cardiovascular surgery, cardiac computed tomography (CT) has served an important role in association with the improvement of the spatial and temporal resolution. Because CT angiography (CTA) provides more available information than plain CT, CTA has been increasingly used to access the coronary arteries and graft patency after coronary artery bypass grafting (CABG). Recently, minimally invasive cardiac surgeries, including CABG with left mini-thoracotomy and mitral valve surgery with right mini-thoracotomy, are revived, which requires preoperative CTA to make a strategy of incision placement on the basis of anatomical relationship between the target structure of the heart and the thorax. In Japan, transcatheter aortic valve implantation (TAVI) was approved in the late 2013, and is expected to be widely performed in the future. CTA is extremely useful for TAVI patients to determine the choice of the valve size and the surgical approach. CT provides many other valuable findings to us, but if we cannot fully leverage it in the daily cardiovascular surgery, its value is decreased. We have to acquire enough skill to maximize the performance of CT in the practical clinical setting.

Dynamic late gadolinium enhancement simply quantified using myocardium to lumen signal ratio: normal range of ratio and diffuse abnormal enhancement of cardiac amyloidosis.

PURPOSE: To detect abnormal myocardial tissue in patients with diffuse myocardial disease, we propose a simple technique of late gadolinium enhancement (LGE) using routine myocardial imaging modalities. MATERIALS AND METHODS: We retrospectively reviewed LGE images from 51 patients with normal myocardium and 10 patients with pathologically proven cardiac amyloidosis (CA). We obtained sequential LGE images from patients at 2, 5, 10, and 20 minutes after injection of Gd-DTPA (0.15 mmol/kg) with a fixed inversion time of 300 msec. We evaluated the signal intensity ratio of the myocardium to the left ventricular lumen (M/L) in one long and two short axial sections within 463 and 120 segments of normal myocardium and CA, respectively. Visually unenhanced and enhanced regions of myocardium were evaluated in each segment of patients with CA. RESULTS: Among normal myocardium, M/L (means ± standard deviation; SD) was stable with time (2, 5, 10, and 20 min: 0.34 ± 0.03, 0.31 ± 0.05, 0.34 ± 0.07, and 0.42 ± 0.11, respectively). The calculated M/L of unenhanced (0.60 ± 0.20, 0.68 ± 0.19, 0.76 ± 0.20, and 1.09 ± 0.25, respectively) and enhanced myocardium (0.77 ± 0.27, 0.99 ± 0.29, 1.20 ± 0.40, and 1.45 ± 0.54, respectively) in patients with CA was significantly greater than that seen for the normal myocardium at each time and increased over time. CONCLUSION: In patients with CA, diffuse myocardial abnormalities can be demonstrated using M/L, and this technique may be useful for the characterization of other myocardial diseases.

An elderly case of right ventricular outflow obstruction precisely diagnosed and successfully treated with surgical repair.

Congenital diseases causing an obstruction of the right ventricular outflow are difficult to precisely diagnose, especially in elderly patients. Here, we describe a 76-year-old woman who presented to our hospital with shortness of breath on exertion and was finally diagnosed as infundibular pulmonary stenosis by multiple modalities. Surgery was successfully performed and the symptom was relieved. This case underscored the usefulness of multiple modalities for the precise assessment of the right ventricular outflow obstruction and the effectiveness of surgery even in elderly patients with infundibular pulmonary stenosis.

Dual-energy CT head bone and hard plaque removal for quantification of calcified carotid stenosis: utility and comparison with digital subtraction angiography.

We evaluated quantification of calcified carotid stenosis by dual-energy (DE) CTA and dual-energy head bone and hard plaque removal (DE hard plaque removal) and compared the results to those of digital subtraction angiography (DSA). Eighteen vessels (13 patients) with densely calcified carotid stenosis were examined by dual-source CT in the dual-energy mode (tube voltages 140 kV and 80 kV). Head bone and hard plaques were removed from the dual-energy images by using commercial software. Carotid stenosis was quantified according to NASCET criteria on MIP images and DSA images at the same plane. Correlation between DE CTA and DSA was determined by cross tabulation. Accuracies for stenosis detection and grading were calculated. Stenosis could be evaluated in all vessels by DE CTA after applying DE hard plaque removal. In contrast, conventional CTA failed to show stenosis in 13 out of 18 vessels due to overlapping hard plaque. Good correlation between DE plaque removal images and DSA images was observed (r (2) = 0.9504) for stenosis grading. Sensitivity and specificity to detect hemodynamically relevant (>70%) stenosis was 100% and 92%, respectively. Dual-energy head bone and hard plaque removal is a promising tool for the evaluation of densely calcified carotid stenosis.

Dual-energy direct bone removal CT angiography for evaluation of intracranial aneurysm or stenosis: comparison with conventional digital subtraction angiography.

Dual-energy CT can be applied for bone elimination in cerebral CT angiography (CTA). The aim of this study was to compare the results of dual-energy direct bone removal CTA (DE-BR-CTA) with those of digital subtraction angiography (DSA). Twelve patients with intracranial aneurysms and/or ICA stenosis underwent a dual-source CT in dual-energy mode. Post-processing software selectively removed bone structures using the two energy data sets. Three-dimensional images with and without bone removal were reviewed and compared to DSA. Dual-energy bone removal was successful in all patients. For 10 patients, bone removal was good and CTA maximum-intensity projection (MIP) images could be used for vessel evaluation. For two patients, bone removal was moderate with some bone remnants, but this did not inhibit the three-dimensional visualization. Three aneurysms adjacent to the skull base were only partially visible in conventional CTA but were fully visible in DE-BR-CTA. In five patients with ICA stenosis, DE-BR-CTA revealed the stenotic lesions on the MIP images. The correlation between DSA and DE-BR-CTA was good (R (2)=0.822), but DE-BR-CTA led to an overestimation of stenosis. DE-BR-CTA was able to eliminate bone structure using only a single CT data acquisition and is useful to evaluate intracranial aneurysms and stenosis.