Is Preoperative Delineation of Coronary Artery Pattern a Prerequisite for Arterial Switch Operation?

The Leiden Convention coronary coding system: translation from the surgical to the universal view

AIMS

The Leiden Convention coronary coding system structures the large variety of coronary anatomical patterns; isolated and in congenital heart disease. It is widely used by surgeons but not by cardiologists as the system uses a surgeons' cranial view. Since thoracic surgeons and cardiologists work closely together, a coronary coding system practical for both disciplines is mandatory. To this purpose, the 'surgical' coronary coding system was adapted to an 'imaging' system, extending its applicability to different cardiac imaging techniques.

METHODS AND RESULTS

The physician takes place in the non-facing sinus of the aortic valve, oriented with the back towards the pulmonary valve, looking outward from the sinus. From this position, the right-hand sinus is sinus 1, and the left-hand sinus is sinus 2. Next, a clockwise rotation is adopted starting at sinus 1 and the encountered coronary branches described. Annotation of the normal anatomical pattern is 1R-2LCx, corresponding to the 'surgical' coding system. The 'imaging' coding system was made applicable for Computed Tomography (CT), Magnetic Resonance Imaging (MRI), echocardiography, and coronary angiography, thus facilitating interdisciplinary use. To assess applicability in daily clinical practice, images from different imaging modalities were annotated by cardiologists and cardiology residents and results scored. The average score upon evaluation was 87.5%, with the highest scores for CT and MRI images (average 90%).

CONCLUSION

The imaging Leiden Convention is a coronary coding system that unifies the annotation of coronary anatomy for thoracic surgeons, cardiologists, and radiologists. Validation of the coding system shows it can be easily and reliably applied in clinical practice.

Value of preoperative echocardiography for the diagnosis of coronary artery patterns in neonates with transposition of the great arteries

BACKGROUND

Abnormal coronary pattern may complicate coronary transfer during arterial switch operation.

OBJECTIVE

To evaluate the accuracy of echocardiography in assessing the anatomy of coronary arteries in neonates with transposition of the great arteries, and determine impact on outcomes.

METHODS

We conducted a retrospective analysis of data in neonates with transposition of the great arteries. Preoperative echocardiographic coronary artery pattern and surgical intraoperative reports were compared. Mismatch between transthoracic echocardiography and surgical intraoperative reports and the impact on perioperative outcome were assessed. Coronary patterns were classified into four groups: type 1 (normal); type 2 (risk of coronary with intramural course); type 3 (coronary loop); and type 2+3.

RESULTS

Overall, 108 neonates who underwent an arterial switch operation were included: 68 were classified as type 1; seven as type 2; 32 as type 3; and one as type 2+3. Overall, 10 adverse events occurred. Five patients died, three from coronary causes. Survival was 96% at 1 month. Transthoracic echocardiography and surgical intraoperative reports differed in 17.6% of cases. Mortality was 15.8% in case of inappropriate diagnosis and 2.2% for appropriate diagnosis (P=0.01). Mortality in type 2 was 66.7% in case of discordance versus 0% when concordant. Multivariable analysis found that inappropriate preoperative transthoracic echocardiography diagnosis of coronary pattern was the only significant risk factor for mortality (P=0.04).

CONCLUSIONS

Echocardiography can assess coronary artery anatomy in neonates with transposition of the great arteries. Intramural coronary course is often misdiagnosed. Preoperative misdiagnosis of coronary artery anomaly may impact perioperative mortality. However, this assessment will have to be confirmed by further larger studies.

Identification of coronary artery anatomy on dual-source cardiac computed tomography before arterial switch operation in newborns and young infants: comparison with transthoracic echocardiography

BACKGROUND

Considering inherent limitations of transthoracic echocardiography, the diagnostic accuracy of cardiac CT in identifying coronary artery anatomy before arterial switch operation needs to be investigated with recently improved coronary artery visibility using electrocardiogram (ECG)-synchronized dual-source CT.

OBJECTIVE

To compare diagnostic accuracy between cardiac CT using a dual-source scanner and transthoracic echocardiography in identifying coronary artery anatomy before arterial switch operation in newborns and young infants.

MATERIALS AND METHODS

The study included 101 infants (median age 4 days, range 0 days to 10 months; M:F=78:23) who underwent ECG-synchronized cardiac dual-source CT and transthoracic echocardiography before arterial switch operation between July 2011 and December 2016. We evaluated and classified coronary artery anatomy on cardiac CT and transthoracic echocardiography. With the surgical findings as the reference standard, we compared the diagnostic accuracy for identifying coronary artery anatomy between cardiac CT and transthoracic echocardiography.

RESULTS

The most common coronary artery pattern was the usual pattern (left coronary artery from sinus 1 and right coronary artery from sinus 2; 64.4%, 65/101), followed by a single coronary artery from sinus 2 and a conal branch from sinus 1 (7.9%, 8/101), the inverted pattern (5.9%, 6/101), the right coronary artery and left anterior descending artery from sinus 1 and the left circumflex artery from sinus 2 (5.9%, 6/101), and others. In 96 infants with surgically proven coronary artery anatomy, the diagnostic accuracy of cardiac CT was significantly higher than that of transthoracic echocardiography (91.7%, 88/96 vs. 54.2%, 52/96; P<0.0001).

CONCLUSION

Diagnostic accuracy of cardiac CT is significantly higher than that of echocardiography in identifying coronary artery anatomy before arterial switch operation in newborns and young infants.

Preoperative Coronary Anatomy Assessment with Echocardiography and Morbidity After Arterial Switch Operation of Transposition of the Great Arteries

In transposition of the great arteries (TGA), certain coronary patterns have been associated with major adverse events early after the arterial switch operation (ASO). We sought to determine the impact of preoperative echocardiographic (ECHO) diagnosis on the intra- and postoperative morbidity. All patients with TGA born between June 2001 and June 2017 and who underwent ASO were reviewed. Data on presumed coronary anatomy (CA) preoperatively were obtained from the preoperative ECHO report. Intraoperative CA was categorized according to Yacoub classification. Major postoperative morbidity included at least one of the following: delayed sternal closure (DSC), prolonged (> 72 h) mechanical ventilation, reintubation, peritoneal dialysis (PD), ECMO, reoperation, and readmission within 30 days after surgery. 240 patients with median age of 5 days (range 1-614) and mean weight at surgery was 3.6 kg (1.8-8.4) were included. Preoperative ECHO assessment of CA was available in 228 patients. Intraoperatively, 181 patients (75%) were found to have type A, 25 patients had type B or C or intramural (B-C-IM; 10%), and 34 patients had type D or E (D-E; 14%). Patients with types B, C, and intramural coronary (B-C-IM) had increased risk for delayed sternum closure (9/25 vs. 20/181 in type A and 8/34 in type D-E; p = 0.04), peritoneal dialysis (4/25 vs. 8/181 and 1/34; p = 0.04), and ECMO (2/25 vs. 1/131 and 1/34; p = 0.02). Within the B-C-IM group, preoperative ECHO raised suspicion of type A in 13 patients (i.e., incorrect diagnosis, ID; 52%), whereas non-A CA was suspected in 12 patients (i.e., correct diagnosis, CD; 48%). With the exception of reoperation, which was seen only in the ID subgroup (4/12 vs. 0/10 in the CD subgroup; p = 0.04), the intraoperative (cardiopulmonary bypass time and cross-clamp time) and postoperative morbidity indices were comparable in both ID and CD subgroups (p > 0.1). Although there is a significant risk for early postoperative morbidity in TGA patients with single, interarterial, and intramural CA, there seems to be relatively limited influence of preoperative ECHO assessment of coronary anatomy on this morbidity burden.

Prenatal diagnosis of dextrotransposition of the great arteries

Dextrotransposition of the great arteries (DTGA) is a common cardiac cause of cyanosis in newborn infants that can cause acidosis and death within a short period of time unless there is a large atrial-level shunt or a patent ductus arteriosus. Here, we report a case of prenatal diagnosis of DTGA at 24+1 gestational weeks. In a tilted 4-chamber view, the pulmonary trunk branched to the left and the right pulmonary, with its root connected to the left ventricle outflow tract. In the short-axis view, the pulmonary trunk was shown to be parallel with the ascending aortic root. Cesarean section was performed due to the nonreassuring fetal status at 38+5 gestational weeks. The male neonate appeared to have mild cyanotic symptoms and weighed 3,108 g. Apgar scores were 8 and 9 at 1 and 5 minutes, respectively. Neonatal echocardiography was performed immediately after birth and the findings confirmed DTGA associated with atrial septal defect secundum. Postnatally, angiography confirmed the echocardiographic diagnosis of DTGA with a large atrial septal defect secundum and a large patent ductus arteriosus. Jatene arterial switch operation and atrial septal defect closure with Gore-Tex patch were performed. The neonate withstood the operation well and was discharged 27 days after birth weighing 2,950 g and in a stable condition. Prenatal diagnosis of DTGA can greatly aid to prepare the patient's family and the surgeon and significantly improve the outcome of complex heart disease in the neonatal period.

Arterial Switch Operation: Troponin T Does Not Predict Ventilation Requirements

The aim of this study was to assess whether postoperative cardiac troponin T levels could predict ventilation requirements in infants undergoing the arterial switch operation. Cardiac troponin T was measured 6 hours after aortic cross clamping and prior to tracheal extubation in 20 consecutive patients; 10 had simple and 10 had complex (with ventricular septal defect) transposition of the great arteries. The mean plasma troponin T level prior to extubation did not differ significantly in patients who were re-intubated and those who were successfully extubated. The initial cardiac troponin T levels in the complex defect group was significantly higher than in the simple transposition group. There was no correlation between initial cardiac troponin T levels and the duration of mechanical ventilation. There was no difference in mean duration of ventilation between the 2 groups. It was concluded that the postoperative cardiac troponin T level is not a predictor of successful extubation or prolonged artificial ventilation in this subset.