Complexity stratification of the arterial switch operation: a second learning curve

A Simplified Approach to Predicting Reintervention in the Arterial Switch Operation

We investigated patients with transposition anatomy suitable for the arterial switch operation (ASO) to evaluate a simplified approach to prediction of reintervention. A retrospective review was performed of 180 consecutive patients who underwent ASO from 2009 to 2018. Patients were classified as Category I (n = 122) d-transposition of great arteries (dTGA) + intact ventricular septum, Category II (n = 28) dTGA + ventricular septal defect (VSD) and Category III (n = 30) dTGA + Aortic arch obstruction (AAO) +/- VSD or Taussig-Bing Anomaly (TBA) +/- AAO. Outcomes included reintervention-free survival (using Kaplan-Meier estimates) and predictors of reintervention. Median follow up was 3.3 (interquartile range 1.7-5.8) years with no difference between categories(P = 0.082). There were 3 mortalities- 2 early (one each in Category I and II) and one late (in Category I). Reintervention-free survival for the whole group at 1, 3, 5 and 8 years was 94%, 91%, 90% and 86% respectively. Conventional criteria predicting reintervention included the presence of TBA(P = 0.0054) and AAO(P = 0.027). Low birth weight did not predict reintervention(P = 0.2). When analyzed by category, multivariable analysis showed that patients in Category III carried a high risk of reintervention [Hazard risk (HR) = 7.43, 95% confidence interval (CI)=(2.39, 23.11), P < 0.001], but so did those in Category II [HR=6.90, 95% CI = (2.19, 21.75, P < 0.001] when compared to Category I. Conventional risk factors for technical difficulty may not be the best predictors of reintervention. A simplified approach highlights Category II patients (dTGA + VSD) as being at substantial risk of re-intervention, and not part of a low risk cohort.

Arterial switch operation in patients with Taussig-Bing anomaly and aortic arch obstruction

BACKGROUND

Arterial switch operation (ASO) in children with Taussig-Bing anomaly and associated aortic arch obstruction (AAO) is technically demanding. This study sought to determine outcomes of patients with Taussig-Bing anomaly and AAO who underwent ASO at a single institution.

METHODS

From 1983 to 2015, 844 patients underwent an ASO for biventricular repair at The Royal Children's Hospital. Twenty-eight (3.3%, 28/844) patients had Taussig-Bing anomaly and AAO.

RESULTS

Twenty-one (75%, 21/28) patients underwent ASO and AAO repair as a single stage procedure and 7 (25%, 7/28) patients had arch repair prior to ASO. There were no early or late deaths. Follow-up after hospital discharge was available for all patients. Median follow-up was 17.5 years (interquartile range 9.2 to 22.3 years, range 4.0 to 31.5 years). All patients were in NYHA Class I at last follow-up. Freedom from reintervention was 61% (95%CI 40-76%) and 56% (95%CI 36-73%) at 5 and 15 years after ASO. The most common reinterventions were repair of recurrent AAO, branch pulmonary artery stenosis and neo-aortic valve repair. Four (14%, 4/28) patients required 5 reinterventions (3 reoperations and 2 catheter reintervention) for recurrent AAO at a median 2.2 years after ASO (interquartile range 2.1-2.3 years).

CONCLUSIONS

Patients with Taussig-Bing anomaly and AAO can undergo the ASO with excellent survival. Reintervention is equally common for both left and right sided obstruction.

Commissural Malalignment as a predictor of coronary artery abnormalities in patients with transposition of great arteries

Background

In patients with transposition of the great arteries (TGA), commissural malalignment (CM) between semilunar valves may be associated with abnormal coronary (CA) pattern. We intend to assess the degree of CM with incidence of unusual CA anatomy.

Methods

We proposed a ratio to measure the distance of both ends of the anterior facing sinuses of the pulmonary valve from the facing commissure of the aortic valve. We labeled it as D1 and D2 distance. A ratio (C ratio) of the smaller distance (either D1 or D2 whichever is shorter) over the sum of both D1 and D2 was taken (D1 or D2 whichever is shorter / D1 + D2). We related this ratio with the incidence of the unusual CA anatomy in D-TGA patients.

Results

We had a total of 158 patients. We defined the point beyond which the C-Ratio becomes significantly associated with abnormal coronary artery pattern, this represents the median effective level (EL50). The EL50 of the C-Ratio was found to be equal to 31% (0.31). The prediction revealed that the CA pattern would most probably be usual when there is a minor commissural malalignment (C-Ratio less than the EL50) and most probably be unusual when there is a major malalignment (C-Ratio is greater than the EL50). The sensitivity was 71% and the specificity 88% (p-value < 0.0001).

Conclusions

The C-Ratio helps to categorize the degree of CM as minor (less than 0.31) or major (more than 0.31). A higher C-Ratio predicts a higher incidence of unusual CA pattern.

Transposition of the great vessels and intact ventricular septum: is there an age limit for the arterial switch? Personal experience and review of the literature

OBJECTIVE

Prognosis of the transposition of the great arteries has completely changed since the introduction of the arterial switch. Time limit to perform this intervention is still controversial. The aim of this study is to demonstrate the early and late outcome of primary arterial switch operation beyond the age of months.

METHODS

We included all patients with the diagnosis of transposition of the great arteries with intact ventricular septum beyond the age of 8 weeks who underwent primary arterial switch operation. The procedures were performed by the same surgeon, in two different institutes. Patients who had transposition of the great arteries and associated anomalies (except atrial septal defect and persistent arterial duct) were excluded. Ventricular shape, geometry, and mass were not considered during the decision on procedure type.

RESULTS

In the study, 11 patients with the diagnosis of simple d-transposition of the great arteries beyond 8 weeks were undergone primary arterial switch operation with a mean age of 90.63 days (60-137 days), and 7 patients had a Rashkind procedure. All patients had squashed left ventricle shape with preserved function. The sternum was left open in 10 patients. Extracorporeal membrane oxygenation support was necessary in 45.45% of cases. The mean mechanical ventilation time was 7.27 days (1-16 days). No mortality was recorded until now. Post-operatory left ventricular function was preserved in 90.9% of the patients. Only one patient had mild myocardial dysfunction at the time of discharge.

CONCLUSIONS

Primary arterial switch procedure can still be the best surgical option in patients with the diagnosis of transposition of the great arteries with intact ventricular septum beyond 8 weeks of age, providing that mechanical circulatory support and an expert cardiac intensive care unit service are available.

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.

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.

Arterial Switch Operation With and Without Coronary Relocation for Intramural Coronary Arteries

BACKGROUND

The arterial switch operation (ASO) for the transposition of the great arteries (TGA) with intramural coronary arteries has been performed using several techniques to avoid coronary events. We mainly performed ASO without coronary relocation by creating an aortopulmonary fenestration (Imai technique). Coronary circulation was rerouted by covering the aortopulmonary window and coronary orifices with a nonfacing sinus flap. Long-term results have not been reported. We describe our early and late results.

METHODS

Among 551 patients who underwent an ASO between 1985 and 2014, intramural coronary arteries were detected in 15 of them. Coronary arteries were managed using 2 techniques: the double-button method in 5 patients (with unroofing and trapdoor incision in 1 patient) and the Imai technique in 10 patients.

RESULTS

There were 3 hospital deaths and 3 deaths after discharge, 5 of which showed coronary complications. Actual survival and freedom from coronary complications at 15 years were 70% and 67%, respectively, with the Imai technique and 40% and 20%, respectively, with the double-button method. Late coronary intervention was performed for a long intramural coronary artery stenosis in 1 patient who underwent the Imai technique. In the others, late aortography showed good patency of the aortopulmonary window and growth of the coronary pouch after the Imai technique.

CONCLUSIONS

The Imai technique can be an option for coronary management in the presence of high-risk coronary anatomy, particularly distal intramural coronary artery stenosis and inseparable coronary arteries with an almost single orifice. Adequate neopulmonary artery augmentation must be performed to prevent right ventricular outflow stenosis.

Arterial Switch Operation in Single Coronary Ostium With Intramural Course: Subclavian Artery Patch Angioplasty

This report describes a neonatal arterial switch operation in a transposition of the great arteries with single ostium and intramural course coronary pattern. The technique proposed is based on the creation of two coronary neoostia by incising the left coronary intramural course and splitting the common button followed by a patch enlargement of left coronary button using the left subclavian artery.