Surgery for congenital diseases of the aorta

Strategies for Complex Reoperative Aortic Arch Reconstruction in Patients With Congenital Heart Disease

Aortic dilation is common in patients with congenital heart disease including those with a bicuspid aortic valve, connective tissue disease, coarctation of the aorta, and conotruncal defects. In addition, neo-aortic dilation has been described in patients after aortic reconstruction including the Norwood procedure, the arterial switch operation, and the Ross procedure. Although aortic catastrophe is rare in patients with congenital heart disease, common pathologic endpoints in these patients likely manifest with similar aortic tissue behavior. A lifelong care model with similar indications for surveillance and prophylactic repair to other more common aortopathies is therefore warranted. Still, reoperative aortic arch reconstruction in these patients is often a complex and high-risk endeavor, and in all cases, a tailored and adaptable plan ensuring adequate myocardial and cerebral protection with appropriate rescue measures is paramount. A surgical team taking on these challenging cases should possess an armamentarium of open, hybrid, and endovascular techniques which can be individualized to a patient's unique anatomy, surgical history, and concomitant lesions as well as the team's measured outcomes and experience.

Current spectrum, challenges and new developments in the surgical care of adults with congenital heart disease

Today, more than two thirds of patients with congenital heart disease (CHD) are adults. Cardiac surgery plays an essential role in restoring and maintaining cardiac function, aside from evolving medical treatment and catheter-based interventions. The aim of the present publication was to describe the spectrum of operations performed on adults with CHD (ACHD) by reviewing current literature. Currently, surgery for ACHD is predominantly valve surgery, since valvular pathologies are often either a part of the basic heart defect or develop as sequelae of corrective or palliative surgery. Surgical techniques for valve repair, established in patients with acquired heart disease (non-ACHD), can often be transferred to ACHD. New valve substitutes may help to reduce the number of redo operations. Most of valve operations yield good results in terms of survival and quality of life, with the precondition that the ventricular function is preserved. Heart failure due to end-stage CHD is the most frequent cause of mortality in ACHD. However, surgical treatment by means of mechanical circulatory support (MCS) is still uncommon and the mortality exceeds the one following other operations in ACHD. Currently, different devices are used and new technical developments are in progress. However, there still is no ideal assist device available. Therefore, heart transplantation remains the only valid option for end-stage CHD. Despite higher early mortality following heart transplantation in ACHD compared to non-ACHD, the long-term survival compares favorably to non-ACHD. There is room for improvement by refining the indications, the time of listing, and the perioperative care of ACHD transplant patients. Sudden death is the second most frequent cause of mortality in ACHD. Ventricular tachycardia is the most frequent cause of sudden death followed by coronary artery anomaly. Due to the increasing awareness of physicians and the improved imaging techniques, coronary artery anomalies are coming more into the focus of cardiac surgeons. However, the reported experience is limited and it is currently difficult to provide a standardized and generally applicable recommendation for the indication and the adequate surgical technique. With the increasing age and complexity of ACHD, treatment of rhythm disturbances by surgical ablation, pacemaker or implantable cardioverter defibrillator (ICD) implantation and resynchronisation gains importance. A risk score specifically designed for surgery in ACHD is among the newest developments in predicting the outcome of surgical treatment of ACHD. This evidence-based score, derived from and validated with data from the Society of Thoracic Surgeons Congenital Heart Surgery Database, enables comparison of risk-adjusted performance of the whole spectrum of procedures performed in ACHD and helps in understanding the differences in surgical outcomes. The score is thus a powerful tool for quality control and quality improvement. In conclusion, new developments in surgery for ACHD are currently made with regard to valve surgery, which comprises more than half of all operations in ACHD and in treatment of end-stage CHD, which still yields high mortality and morbidity.

Magnetic resonance imaging 4-D flow-based analysis of aortic hemodynamics in Turner syndrome

BACKGROUND

Cardiovascular surveillance is important in Turner syndrome because of the increased risk of aortic dilation and dissection with consecutively increased mortality.

OBJECTIVE

To compare 4-D flow MRI for the characterization of aortic 3-D flow patterns, dimensions and vessel wall parameters in pediatric patients with Turner syndrome and age-matched controls.

MATERIALS AND METHODS

We performed 4-D flow MRI measuring in vivo 3-D blood flow with coverage of the thoracic aorta in 25 patients with Turner syndrome and in 16 female healthy controls (age mean ± standard deviation were 16 ± 5 years and 17 ± 4 years, respectively). Blood flow was visualized by time-resolved 3-D path lines. Visual grading of aortic flow in terms of helices and vortices was performed by two independent observers. Quantitative analysis included measurement of aortic diameters, quantification of peak systolic wall shear stress, pulsatility index and oscillatory shear index at eight defined sites.

RESULTS

Patients with Turner syndrome had significantly larger aortic diameters normalized to BSA, increased vortices in the ascending aorta and elevated helix flow in the ascending and descending aorta compared to controls (all P<0.03). Patients with abnormal helical or vortical flow in the ascending aorta had significantly larger diameters of the ascending aorta (P<0.03). Peak systolic wall shear stress, pulsatility index and oscillatory shear index were significantly lower in Turner patients compared to controls (p=0.02, p=0.002 and p=0.01 respectively).

CONCLUSION

Four-dimensional flow MRI provides new insights into the altered aortic hemodynamics and wall shear stress that could have an impact on the development of aortic dissections.

Surgical Management of Peripheral Vascular Manifestations of Loeys-Dietz Syndrome

BACKGROUND

Loeys-Dietz syndrome (LDS) is characterized by a triad of aortic aneurysm, vessel tortuosity, and hypertelorism. LDS patients often harbor additional aneurysms and dissections throughout their vasculature. The optimal management of these additional lesions is poorly understood. Accordingly, we sought to analyze our experience with the peripheral arterial manifestations of LDS.

METHODS

Adult and pediatric LDS patients who sought treatment at a single institution from 2005 to 2015 were retrospectively reviewed. Patients were included if radiographic or clinically documented evidence existed of peripheral artery aneurysm or dissection. Standard univariate analyses were performed.

RESULTS

Eighteen LDS patients (aged 1.3-59.3 years, mean age 27.8 years at diagnosis) with aortic (not including root, ascending, or arch) vascular abnormalities were identified. Average follow-up was 5.2 ± 3.8 years. Fourteen (77.8%) patients had peripheral aneurysms, occurring most frequently in the carotid (35.7%), subclavian (35.7%), and visceral (28.6%) segments. Most patients had multiple peripheral segments involved (average 2, range 1-6). Nine (64%) patients with peripheral involvement underwent repair, for a total of 17 operations (average 1.89 operations per patient, range 1-4). Endovascular techniques were used in 4 operations (23.5%), without technical failures. Among patients requiring surgical repair, a history of abdominal aortic repairs was present in 77.8%, yielding a total of 36 vascular repairs (average 4, range 2-7). Perioperative morbidity was 11.8%, with no reported mortalities. Prior aortic dissection was not associated with peripheral surgical repairs (P = 0.58).

CONCLUSIONS

LDS is an aggressive vasculopathy which commonly affects the peripheral vasculature. Our data suggest that open and endovascular procedures may be safe and effective in the LDS periphery and multiple operations are common. As prior aortic dissection did not predict peripheral arterial involvement in LDS, vigilant peripheral arterial surveillance of LDS is warranted regardless of aortic disease state and may be key to early identification and our treatment success.

Long-term outcomes of the arterial switch operation for transposition of the great arteries and ventricular septal defect and/or aortic arch obstruction

OBJECTIVES

Long-term outcomes after the arterial switch operation (ASO) for complex transposition of the great arteries (TGA) should be clarified.

METHODS

A retrospective study was conducted in patients operated on between 1982 and 1998. Overall 220 postoperative survivors, 79.1% with a ventricular septal defect, 13.2% with multiple ventricular septal defects, and 29.1% with aortic arch obstruction, were followed for 17 years (0-28 years).

RESULTS

The conditional survival rate was 96.7% [95% confidence interval (CI): 94.4-99.1] at 25 years. Late sudden death occurred in 2 asymptomatic patients. The cumulative incidence rate of death or reinterventions was 3.8% (95% CI: 2.9-4.8) at 25 years, with age at ASO <10 days and aortic regurgitation at discharge identified as independent risk factors. The cumulative incidence rate of neoaortic regurgitation was 41.6% (95% CI: 20.5-62.8) at 25 years with an aorto-pulmonary diameter mismatch at the time of the ASO, age at ASO <10 days and aortic regurgitation at discharge identified as independent risk factors. At the last follow-up, 53 patients (24.1%) had neoaortic root dilatation with an aortic sinus z-score ≥3 and 6 of them had a Bentall operation at a median delay of 14.1 years since the ASO. The only independent factors for neoaortic root dilatation were male sex and an aorto-pulmonary diameter mismatch at the time of the ASO.

CONCLUSIONS

Despite a continual rate of reinterventions, long-term survival and cardiovascular outcome are excellent after ASO for complex TGA. Dilatation of the neoaortic root and neoaortic regurgitation may be observed with time and 2 late sudden deaths occurred, justifying a close follow-up in all patients.