Early and mid-term results of the arterial switch operation in patients with intramural coronary artery

Techniques and pitfalls of coronary arterial reimplantation in anatomical correction of transposition

BACKGROUND AND AIM

We assessed the anatomical variations in coronary arterial patterns relative to the techniques of reimplantation in the setting of the arterial switch operation, relating the variations to influences on outcomes.

METHODS

We reviewed pertinent published investigations, assessing events reported following varied surgical techniques for reimplantation of the coronary arteries in the setting of the arterial switch procedure.

RESULTS

The prevalence of reported adverse events, subsequent to reimplantation, varied from 2% to 11%, with a bimodal presentation of high early and low late incidence. The intramural pattern continues to contribute to mortality, with some reports of 28% fatality. The presence of abnormal course relative to the arterial pedicles in the setting of single sinus origin was associated with a three-fold increase in mortality. Abnormal looping with bisinusal origin of arteries was not associated with increased risk.

CONCLUSION

The techniques of transfer of the coronary arteries can be individually adapted to cater for the anatomical variations. Cardiac surgeons, therefore, need to be familiar with the myriad creative options available to achieve successful repair when there is challenging anatomy. Long-term follow-up will be required to affirm the superiority of any specific individual technique. Detailed multiplanar computed-tomographic scanning can now reveal all the variants, and elucidate the mechanisms of late complications. Coronary angioplasty or surgical revascularization may be considered in selected cases subsequent to the switch procedure.

Lessons learned from ECMO support in pediatric patients with D-transposition of the great arteries: preoperative, intraoperative and postoperative

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) support on D-transposition of the great arteries (D-TGA) carries formidable challenges.

METHODS

A retrospective study was performed on pediatric patients with D-TGA supported by ECMO from July 2007 to December 2019. This study summarized the clinical experience of ECMO support in pediatric patients with D-TGA preoperative, intraoperative, and postoperative.

RESULTS

Overall, 16 children with D-TGA received ECMO support during this period. Two (2 of 16) were supported before cardiac surgery, 3 (3 of 16) were supported postoperatively in the intensive care unit, and 11 (11 of 16) failed to wean off cardiopulmonary bypass. Two cases of preoperative ECMO support for patients with D-TGA with an intact ventricular septum and restrictive atrial septum due to severe hypoxemia died. In this study, D-TGA with coronary artery malformation and other complicated deformities died (8 of 14), whereas uncomplicated D-TGA without coronary artery malformation all survived (6 of 14). The wean-off rate of ECMO patients supported in D-TGA was 62.5% (10 of 16), while the 30-day survival rate was 44% (7 of 16).

CONCLUSION

Although a promising ECMO weaning rate was obtained, 30-day survival of this population was frustrating, mainly attributed to the original anatomy of coronary arteries and the concomitant deformities.

Intramural coronary pattern in patients with transposition: incidence and impact on follow-up

OBJECTIVES

Coronary complications are still the main reason for early mortality after an arterial switch operation. The high incidence of coronary anomalies in patients with transposition of the great arteries may increase the difficulty of coronary transfer, and among them, an intramural pattern was shown to be an independent risk factor of early mortality. However, recently published studies have reported that this rare coronary variant has no impact on the survival rate. The aim of this study was to assess the frequency of intramural coronary patterns in patients with transposition and the impact on overall mortality after an arterial switch operation. Additionally, we presented all coronary arrangements associated with intramural patterns in our cohort and the surgical techniques used to manage them successfully.

METHODS

All arterial switch operations were retrospectively reviewed. In each case, the surgical reports contained detailed graphical representations and coronary anatomy patterns. All operatively confirmed intramural patterns were included in the analysis.

RESULTS

Among 806 patients, 271 patients had coronary anomalies (33.62%), and 28 patients had an intramural pattern (3.47%), which was frequently associated with other complex coronary anomalies (P < 0.001). Overall survival was significantly higher in patients with intramural coronary artery patterns than in those with other coronary variants (21.34% vs 8.74%, P = 0.024, log-rank test).

CONCLUSIONS

Intramural patterns associated with transposition remain a surgical challenge and increase overall mortality in our cohort. To reliably confirm or reject the significance of the observed impact of this rare coronary variant, a multicentre data analysis is required.

Clinical Outcome of Patients with Transposition of the Great Arteries and Intramural Coronary Artery

To review the early and intermediate outcomes of patients with transposition of the great arteries (TGA) and intramural coronary artery (IMCA) who underwent arterial switch operation (ASO) at our center. Among 450 patients with TGA who underwent an ASO between 2010 and 2018, 26 (5.8%) patients were identified with IMCA. The left coronary artery was intramural in 21 of 26 patients. We adopted coronary transfer using double coronary buttons with unroofed intramural course for all 26 patients. Early mortality for patients with IMCA was 3 of 26 (11.5%) compared with 10 of 424 (2.4%) for those without IMCA (p = 0.007). Six patients suffered major adverse events, including extracorporeal membrane oxygenation support in 3 patients, delayed sternal closure in 6 patients. The follow-up was available for all 23 survivors, with the mean follow-up period of 73.5 ± 28.7 months. There was no late death and reinterventions, and all patients were asymptomatic at last follow-up. One patient exhibited moderate neopulmonary regurgitation, and 1 patient presented with distal stenosis of the right pulmonary artery. Coronary transfer using double coronary buttons with unroofed intramural course was a good option for patients with TGA and IMCA. With this technique, ASO could be performed with optimal early and intermediate outcomes.

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.