Reoperative Techniques for Complications After Arterial Switch

Valve-Sparing Neo-Aortic Root Replacement for Neo-Aortic Root Dilatation 20 Years after Arterial Switch Operation for Transposition of the Great Arteries: A Case Report

A 25-year-old man returned to Seoul National University Children's Hospital with mild dyspnea on exertion. He had undergone an arterial switch operation at 1 month after birth to correct a complete transposition of the great arteries and a ventricular septal defect. When the patient was 15 years old, dilatation of the neo-aortic sinus and annulus was first identified; since then, it had gradually increased. Given the young age of the patient and the degree of aortic regurgitation (AR), which was mild to moderate, we opted to perform a valve-sparing neo-aortic root replacement with aortic valve repair. Postoperative echocardiography showed successful reductions in the sizes of the aortic sinus and annulus, with only mild AR remaining.

Early Outcomes of Patients Undergoing Neoaortic Valve Repair Incorporating Geometric Ring Annuloplasty

OBJECTIVES

During congenital heart surgery, the pulmonary valve and root may be placed into the systemic position, yielding a "neoaortic" valve. With the stress of systemic pressure, the pulmonary roots can dilate, creating aneurysms and/or neoaortic insufficiency (neoAI). This report analyzes the early outcomes of patients undergoing neoaortic valve repair incorporating geometric ring annuloplasty.

METHODS

Twenty-one patients underwent intended repair at six centers and formed the study cohort. Thirteen had previous Ross procedures, five had arterial switch operations, and three Fontan physiology. Average age was 21.7 ± 12.8 years (mean  ±  SD), 80% were male, and 11 (55%) had symptomatic heart failure. Preoperative neoAI Grade was 3.1  ±  1.1, and annular diameter was 30.7  ±  6.5 mm.

RESULTS

Valve repair was accomplished in 20/21, using geometric annuloplasty rings and leaflet plication (n = 13) and/or nodular release (n = 7). Fourteen had neoaortic aneurysm replacement (13 with root remodeling). Two underwent bicuspid valve repair. Six had pulmonary conduit changes, one insertion of an artificial Nodulus Arantius, and one resection of a subaortic membrane. Ring size averaged 21.9  ±  2.3 mm, and aortic clamp time was 171  ±  54 minutes. No operative mortality or major morbidity occurred, and postoperative hospitalization was 4.3  ±  1.4 days. At discharge, neoAI grade was 0.2  ±  0.4 (P < .0001), and valve mean gradient was ≤20 mm Hg. At average 18.0  ±  9.1 months of follow-up, all patients were asymptomatic with stable valve function.

CONCLUSIONS

Neoaortic aneurysms and neoAI are occasionally seen late following Ross, arterial switch, or Fontan procedures. Neoaortic valve repair using geometric ring annuloplasty, leaflet reconstruction, and root remodeling provides a patient-specific approach with favorable early outcomes.

Risk Factors for Reoperation After Arterial Switch Operation

OBJECTIVE

The timing and nature of and risk factors for reoperation after the arterial switch operation in the setting of d-transposition of the great arteries requires further elucidation.

METHODS

A total of 403 patients who underwent arterial switch operation from 1986 to 2017 were reviewed. Institutional preference was for pulmonary artery reconstruction using a pantaloon patch of fresh autologous pericardium. The targets for coronary artery reimplantation were identified by intermittent root distension. Multivariable analysis was used to identify risk factors for reoperation.

RESULTS

Median follow-up was 8.6 years (interquartile range [IQR]: 2-16.9). Pulmonary arterioplasty was the most common reoperation (n = 11, 2.7%) at 3.3 years (IQR: 1.4-11.4) postoperatively. Subvalvar right ventricular outflow tract reconstruction (RVOTR) was required in nine (2.2%) patients at 2.5 years (IQR: 1.1-5.3) postoperatively. Aortic valve repair or replacement (AVR/r) was required in seven (1.7%) patients at 13.6 years (IQR: 10.0-15.8) postoperatively. Aortic root replacement (ARR) and Coronary Artery Bypass Graft/coronary patch arterioplasty were required in five (1.2%) patients each at 13.6 years (IQR: 11.0-15.3) and 11.3 years (IQR: 2.3-13.6) postoperatively, respectively. Taussig-Bing anomaly was a risk factor for any reoperation (P = .034). Risk factors for specific reoperations included ventricular septal defect for AVR/r (P = .038), Taussig-Bing anomaly for RVOTR (P = .004), and pulmonary artery banding for ARR (P = .028).

CONCLUSIONS

Pantaloon patch pulmonary artery reconstruction and intermittent neo-aortic root distension during coronary reimplantation have minimized respective outflow tract reoperations. Certain anatomic subsets carry different risks for late reoperation, and pulmonary artery and/or RVOT reinterventions tend to occur sooner than aortic reinterventions. Special attention to these higher risk subpopulations will be critical to optimizing lifelong outcomes.

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.

Pulmonary artery and lung parenchymal growth following early versus delayed stent interventions in a swine pulmonary artery stenosis model

OBJECTIVES

Compare lung parenchymal and pulmonary artery (PA) growth and hemodynamics following early and delayed PA stent interventions for treatment of unilateral branch PA stenosis (PAS) in swine.

BACKGROUND

How the pulmonary circulation remodels in response to different durations of hypoperfusion and how much growth and function can be recovered with catheter directed interventions at differing time periods of lung development is not understood.

METHODS

A total of 18 swine were assigned to four groups: Sham (n = 4), untreated left PAS (LPAS) (n = 4), early intervention (EI) (n = 5), and delayed intervention (DI) (n = 5). EI had left pulmonary artery (LPA) stenting at 5 weeks (6 kg) with redilation at 10 weeks. DI had stenting at 10 weeks. All underwent right heart catheterization, computed tomography, magnetic resonance imaging, and histology at 20 weeks (55 kg).

RESULTS

EI decreased the extent of histologic changes in the left lung as DI had marked alveolar septal and bronchovascular abnormalities (p = .05 and p < .05 vs. sham) that were less prevalent in EI. EI also increased left lung volumes and alveolar counts compared to DI. EI and DI equally restored LPA pulsatility, R heart pressures, and distal LPA growth. EI and DI improved, but did not normalize LPA stenosis diameter (LPA/DAo ratio: Sham 1.27 ± 0.11 mm/mm, DI 0.88 ± 0.10 mm/mm, EI 1.01 ± 0.09 mm/mm) and pulmonary blood flow distributions (LPA-flow%: Sham 52 ± 5%, LPAS 7 ± 2%, DI 44 ± 3%, EI 40 ± 2%).

CONCLUSION

In this surgically created PAS model, EI was associated with improved lung parenchymal development compared to DI. Longer durations of L lung hypoperfusion did not detrimentally affect PA growth and R heart hemodynamics. Functional and anatomical discrepancies persist despite successful stent interventions that warrant additional investigation.

Predictors of neo-aortic valve regurgitation in the long term after arterial switch operation

Although arterial switch operations (ASOs) have been performed globally to repair d-transposition of the great arteries (d-TGA) in neonates and infants, few studies have been reported regarding the influence of the hemodynamics of patients with d-TGA who have undergone ASO on the development of neo-aortic valve regurgitation (AR). We aimed to investigate the relationship between the hemodynamics and development of AR after ASO in patients with d-TGA by catheter evaluation. This observational study screened 114 consecutive patients who underwent ASO for d-TGA or Taussig-Bing anomaly and who subsequently underwent catheter evaluations in our institution. We reviewed their records for the past 20 years and collected their first catheterization data post-ASO in early childhood. Thirty-six post-ASO patients who underwent catheter evaluations in both the early surgical and long-term phases were finally analyzed. Patients were divided into the following groups according to the presence of significant AR in the long-term phase: the AR group (n = 9 with AR ≥ grade II by the Sellers classification) and the non-AR group (n = 27 with AR < grade II). In the long-term phase, the diastolic blood pressure was significantly lower and the ascending aortic diameter was significantly larger in the AR group than in the non-AR group (p = 0.004 and p = 0.006, respectively). The systolic blood pressure (SBP) and pulse pressure (PP) were similar in both groups. Meanwhile, in the early surgical phase, SBP and PP were significantly higher in the AR group than in the non-AR group (p = 0.029 and p = 0.002, respectively). The receiver operating characteristic curve for late AR showed that the area under the curve for SBP and PP in the early surgical phase were 0.746 and 0.853, respectively. Even though sensitivity analysis was performed, SBP or PP greater than the cutoff value in the early surgical phase was identified as predictors for late AR. Our results suggested that high SBP or PP in the early surgical phase could influence the development of AR in the long term after ASO.

The poor long-term outcomes of owl's eye pulmonary reconstruction technique after arterial switch operation

OBJECTIVES

This study aims to compare the early- and long-term outcomes of patients who undergo owl's eye pulmonary artery (PA) reconstruction to those of patients who undergo conventional PA reconstruction.

METHODS

From January 2016 to January 2017, 64 consecutive patients underwent an arterial switch operation. The patients were divided into 2 groups in terms of neo-PA reconstruction method: 30 patients who underwent neo-PA reconstruction by owl's eye technique were defined as group 1 and 34 patients who underwent neo-PA reconstruction by the conventional approach were defined as group 2. In the final model, after propensity matching, 23 patients from each group with similar propensity scores were included in the study.

RESULTS

There was no significant difference between the groups regarding patient characteristics and operative findings. In the early period, the duration of intensive care unit and hospital stays and the rate of mild neo-pulmonary stenosis (neo-PS) were significantly higher in the owl's eye group (P = 0.04, 0.04 and 0.03). In the late period, the rate of severe neo-PS and reintervention was significantly higher in the owl's eye group (P = 0.02 and 0.04). Furthermore, the rates of 3-year freedom from pulmonary reintervention and freedom from moderate-severe neo-PS were significantly lower in group 1 (P = 0.04). In addition, the owl's eye reconstruction was the only factor independently related to moderate-severe neo-PS in the long term (hazard ratios = 11.2, P = 0.02).

CONCLUSIONS

We have abandoned the owl's eye method for neo-PA reconstruction of the neo-PA because of serious complications. According to our series and the literature, reconstruction of the neo-PA with an oversized, pantaloon-shaped fresh autologous pericardial patch is still superior to the other techniques.

Does Coronary Reimplantation After Neoaortic Reconstruction Increase Aortic Regurgitation?

Coronary reimplantation after neoaortic reconstruction (CRANR) in the arterial switch operation (ASO) allows easy selection of accurate coronary transfer sites in the distended neoaorta. However, neoaortic valve injury may occur during coronary reimplantation. We determined whether the CRANR procedure increased the incidence of aortic valve regurgitation (AR) after ASO. Between March 1994 and August 2017, 227 patients underwent ASO. Since September 2000 CRANR has been performed on 155 patients and open coronary reimplantation (OCR) on 72. Patients who had undergone aortocoronary flaps procedures (n = 13), had early or late mortality (n = 27), or lacked data (n = 11) were excluded. We enrolled and retrospectively reviewed the medical records of 176 patients who were followed up for postoperative AR: 38 underwent OCR and 138 underwent CRANR. We compared the incidences of early and late postoperative AR in both groups. We defined mild or greater AR as "significant AR." The groups did not differ in body weight at operation, great artery relationship, and coronary artery anatomy. The incidences of significant AR at discharge were 21.1% (8/38) in the OCR group and 16.6% (23/138) in the CRANR group (p = 0.53). The freedom from significant AR at 5 years was 59.9% in the OCR group and 62.4% in the CRANR group with no difference between the two groups (p = 0.73). Moderate AR occurred in one patient in the CRANR group. No surgical intervention was required for the aortic valve in either group. ASO using the CRANR technique did not increase the incidence of postoperative early and late AR.

Mid- and Longterm Neo-Aortic Valve Regurgitation after Jatene Surgery: Prevalence and Risk Factors

Background

Jatene surgery became the surgical procedure of choice to repair transposition of the great arteries (TGA) in neonates and infants. Late complications, mainly related to the pulmonary outflow tract and coronary arteries, are well known. The behavior of the neo-aortic valve is a cause of concern because of its potential for requiring late reoperation.

Objectives

To assess the prevalence and risk factors of neo-aortic valve regurgitation in 127 patients in the late postoperative period of the Jatene surgery.

Methods

Of the 328 survivors of the Jatene surgery at the Biocor Institute from October 1997 to June 2015, all patients undergoing postoperative follow-up were contacted via telephone, 127 being eligible for the study. The patients were divided into two groups, simple TGA and complex TGA groups, with follow-up means of 6.4 ± 4.7 years and 9.26 ± 4.22 years, respectively. Echocardiography was performed with adjusted measurements (Z-score) of the neo-aortic annulus, sinus of Valsalva, sinotubular region and ascending aorta, as well as quantification of the neo-aortic valve regurgitation grade.

Results

The incidence of mild neo-aortic valve regurgitation was 29% in a follow-up of 7.4 ± 4.7 years. Moderate regurgitation was identified in 24 patients with age mean (± standard-deviation) of 9.81 ± 4.21 years, 19 of whom (79%) in the complex TGA group. Those patients had a higher aortic annulus Z-score. The reoperation rate due to neo-aortic regurgitation associated with aortic dilation was 1.5%, all patients in the complex TGA group.

Conclusion

This study shows that, despite the low incidence of reoperation after Jatene surgery due to neo-aorta dilation and neo-aortic valve regurgitation, that is a time-dependent phenomenon, which requires strict vigilance of the patients. In this study, one of the major risk factors for neo-aortic valve regurgitation was the preoperative pulmonary artery diameter (p < 0.001).

Successful Late Recruitment of the Occluded Left Main Coronary Artery After Initial Arterial Switch Operation

We describe a surgical technique for late recruitment of the proximally occluded left main coronary artery (LMCA) after initial arterial switch operation, which had been complicated by severe left ventricular dysfunction. This technique allowed for LMCA recanalization, using the patent conal artery branching off the LMCA close to the ostium. It is particularly useful in small children, where surgical options for coronary arteries are limited and associated with a high risk of restenosis. It was successfully used in a two-month-old boy with successful revascularization confirmed by angiography.

Usefulness of Routine Coronary CT Angiography in Patients with Transposition of the Great Arteries After an Arterial Switch Operation

Coronary complications in patients with transposition of the great arteries (TGA) after an arterial switch operation (ASO) are relatively rare, but of all the possible postoperative adverse events, they are potentially the most dangerous. The fate of the coronary arteries, which are transplanted during the neonatal ASO, remains uncertain. There is also no consensus regarding their postoperative evaluation, especially in asymptomatic patients. The aim of this study was to present the early results of routinely performed coronary computed tomography angiography (CCTA) in asymptomatic adolescents and young adults with TGA after an ASO. An initial series of 50 CCTAs performed in asymptomatic patients with TGA after an ASO were evaluated. In each case, a detailed examination of the coronary anatomy, its relationship to the surrounding structures, its exact position in the neoaortic sinus, and the presence of significant coronary abnormalities was performed. The CT scans revealed significant coronary abnormalities in 12 asymptomatic patients: three had acute proximal angulation and stenosis, four had an intra-arterial course, seven had a muscular bridge, one had a left anterior descending artery with an intramuscular course, and one had coronary fistulas to the pulmonary arteries. Additionally, in 25 patients, proximal acute angulation of at least one coronary artery was detected, and four of them had a high ellipticity index. Most of the potentially severe anatomical features were related to the left coronary artery or the left anterior descending artery. CCTA routinely performed on asymptomatic patients with TGA after an ASO provides accurate and useful information for postoperative management. The frequency of coronary anomalies and potentially dangerous anatomical features in this group of patients is high, and their impact on postoperative follow-up remains unknown.

Coronary Artery Anomalies in Patients With Transposition of the Great Arteries and Their Impact on Postoperative Outcomes

BACKGROUND

Coronary anomalies are frequently present in children with transposition of the great arteries (TGA). Such anomalies significantly increase the complexity of arterial switch operations and may have an effect on postoperative outcomes. In this study, we aimed to assess the frequency of coronary anomalies in children with TGA and describe their effect on postoperative outcomes.

METHODS

All patients with TGA who underwent an arterial switch operation between 1991 and 2015 were consecutively enrolled in this study. Patient coronary patterns were obtained from corresponding operative reports and analyzed to determine their associations with adverse postoperative outcomes.

RESULTS

The study included 715 patients with isolated and complex TGA. Coronary anomalies were present in 33.7% of patients and were significantly correlated with the side-by-side configuration of the great arteries. Coronary sinuses with more than 1 ostium were associated with a significantly increased risk of postoperative death (hazard ratio [HR], 2.58), and coronary arteries with a single ostium were associated with an increased risk of postoperative reinterventions (HR, 2.49). In contrast, the trap-door technique of coronary artery transplantation was associated with a reduced risk of reinterventions during postoperative follow-up (HR, 0.40). Complex coronary anomalies were significantly associated with postoperative coronary events (HR, 2.12).

CONCLUSIONS

With the exception of patients whose circumflex artery branches off of the right coronary artery, an anomaly that clearly has no effect on postoperative follow-up, patients with unusual coronary patterns are at higher risk for adverse postoperative outcomes than patients with normal coronary anatomy and must be monitored carefully.

Transeptal Aortic Valve Replacement After Arterial Switch in a Patient With Taussig-Bing Anomaly

Aortic valve replacement in patients after arterial switch is technically difficult, especially in patients with small aorta without neoaortic regurgitation. We report a patient with Taussig-Bing anomaly who had fungal endocarditis after several cardiac operations and was successfully treated with transeptal aortic valve replacement concomitant with other surgical and medical treatments.

Late complications and pathological findings of the arterial switch operation

We describe aortic root dilatation, severe aortic regurgitation, and pulmonary artery stenosis that were accidentally diagnosed 23 years after the arterial switch operation for transposition of the great arteries in situs inversus. We successfully performed the modified Bentall procedure and pulmonary artery reconstruction. The pathology of the dilated aortic root revealed intimal atherosclerosis and linear necrosis of the tunica media, suggesting the vulnerability of the pulmonary artery to systemic pressure.

Past, present, and future of the arterial switch operation: historical review

The arterial switch operation is the extant surgical correction after a long series of palliations attempted and/or successfully achieved for the treatment of discordant ventriculoarterial connections. As early as 1954, pioneers such as Mustard, Bailey, Kay, and Idriss led the way with at first disheartening failures, temporarily leading to abandoning the procedure. The first successful atrial baffle procedure in 1958 established itself as the procedure of choice for treating discordant ventriculoarterial connections, but tenacity, courage, and vision to pursue anatomic correction finally led to the first successful arterial switch in 1975 by Jatene. After a decade to perfect surgical technique and timing indications for the various anatomic subtypes, the new era of the neonatal arterial switch since the late 1980s set the very high standards that we all know and expect today. Despite excellent early and long-term survival, important residual lesions are increasingly being recognised. Expected anatomic residuals include supravalvar pulmonary stenosis, neoaortic valve insufficiency, and coronary ostial stenosis. Reinterventions and rare, but challenging surgical reoperations address these residual findings with satisfactory outcomes. Quality of life into young adulthood is satisfactory, but functional problems include reduced exercise capacity, diffuse coronary insufficiency, and neurodevelopmental shortcomings, of which the true incidence and potential clinical implications are still unknown. The arterial switch is a spectacular anatomic correction for a once lethal condition and currently the best surgical solution for patients with discordant ventriculoarterial connections. It is, however, far from a true cure; closer and ongoing follow-up for future care will continue to be required.