Outcomes of Prosthetic Valved Conduits for Right Ventricular Outflow Tract Reconstruction

Cardiac Computed Tomographic Angiography Evaluation of Right Ventricle-Pulmonary Artery Conduits with Surgical Correlation

Right ventricle-pulmonary artery (RV-PA) conduits are used in the treatment of certain congenital heart disease (CHD). RV-PA conduit complications might develop over time and require intervention. To evaluate how well cardiac computed tomographic angiography (CCTA) performs compared to transthoracic echocardiography (TTE) in evaluating RV-PA conduit complications by using surgical findings as the reference standard. A retrospective chart review of all patients over a 5-year period who underwent CCTA for RV-PA conduit evaluation was performed. Patient demographics and clinical data were recorded. Preoperative CCTA and TTE findings were compared to the operative findings for concordance or discordance. Forty-one patients were included, 51% females. The complications were conduit stenosis (28.68%), infection (7.17%) and aneurysm/pseudoaneurysm (6.15%). TTE and CCTA were consistently able to visualize focal conduit stenosis (96%). The greatest discrepancy between TTE and CCTA was in evaluating for aneurysm/pseudoaneurysm, where TTE detected only 2/6 (33%) compared to CCTA which detected 6/6 (100%) of the cases. However, TTE was slightly better at detecting conduit infection (3/7, 43%) compared to CCTA (2/7, 29%). Note that 5 out of 7 patients with endocarditis had bovine jugular graft. CCTA and TTE provide similar diagnostic accuracy evaluating certain types of RV-PA conduit complications. However, certain complications were only visualized on CCTA or TTE making both modalities complementary to each other during diagnostic evaluation.

Current development of bovine jugular vein conduit for right ventricular outflow tract reconstruction

Right ventricular outflow tract (RVOT) reconstruction is a common surgical method to treat congenital cardiac lesions, and bovine jugular vein conduit (BJVC) has become a prevalent candidate of prosthetic material for this procedure since 1999. Although many clinical studies have shown encouraging results on BJVCs, complications such as stenosis, aneurysmal dilatation, valve insufficiency, and infective endocarditis revealed in other clinical outcomes still remain problematic. This review describes the underlying mechanisms causing respective complications, and summarizes the current technological development that may address those causative factors. Novel crosslinking agents, decellularization techniques, conduit coatings, and physical reinforcement materials have improved the performances of BJVCs. The authors expect that the breakthroughs in the clinical application of BJVC may come from new genetic research findings and advanced characterization apparatuses and bioreactors, and are optimistic that the BJVC will in the future provide sophisticated therapies for next-generation RVOT reconstruction.

Application of Homograft Valved Conduit in Cardiac Surgery

Valved conduits often correct the blood flow of congenital heart disease by connecting the right ventricle to the pulmonary artery (RV-PA). The homograft valved conduit was invented in the 1960s, but its wide application is limited due to the lack of effective sterilization and preservation methods. Modern cryopreservation prolongs the preservation time of homograft valved conduit, which makes it become the most important treatment at present, and is widely used in Ross and other operations. However, homograft valved conduit has limited biocompatibility and durability and lacks any additional growth capacity. Therefore, decellularized valved conduit has been proposed as an effective improved method, which can reduce immune response and calcification, and has potential growth ability. In addition, as a possible substitute, commercial xenograft valved conduit has certain advantages in clinical application, and tissue engineering artificial valved conduit needs to be further studied.

Medium long-term follow-up outcomes of BalMedic® bovine pericardial bioprosthetic valve in the mitral position

Background

In China, where Rheumatic heart disease is still prevalent, two thirds of valve replacements are in mitral position. Before a valve replacement operation is conducted, most patients have reached Class III/IV heart function under the New York Heart Association (NYHA) classification system. As the background to this disease is quite different to that of degenerated cases, which are more prevalent in Western countries, the development of an artificial heart valve that is suitable for local patients is very significant for China. In this medium long-term clinical follow-up study, a data analysis was conducted of domestic heart valve production for mitral replacement.

Methods

A total of 288 patients who underwent mitral valve replacements from 2005 to 2015 at 2 cardiac surgery centres (i.e., The Affiliated Hospital of Qingdao University, and The First People’s Hospital of Yulin) were evaluated. All implanted bioprostheses were BalMedic^® bovine pericardial bioprosthetic valves, which had been granted marketing approval by the China Food and Drug Administration (CFDA) in 2003. Double valve cases that involved both aortic and mitral replacements were not included in the study. On average, patients were aged 54.5±10.8 (range, 11 to 77 years) before the procedure. The mean follow-up period was 7.2±2.6 years. The study examined the overall survival (OS) curve, and different age group results. To gain further insights into the functions of the valves, the OS curve and the age group results for the reoperation-free and structural valve deterioration (SVD)-free rates are also presented.

Results

The 10-year OS rate was 65.6%, the 10-year reoperation-free rate was 76.3%, and the 10-year SVD-free rate was 58.0%. In relation to the age group results, younger patients had higher survival rates, while older patients had higher reoperation-free rates and SVD-free rates.

Conclusions

In relation to the medium long-term clinical follow-up results, the durability performance of the BalMedic^® bovine pericardial valve in the mitral position was satisfactory, especially among patients whose heart function was worse than that of Western sufferers. Survival rate, reoperation-free rate and SVD-free rate were used for the comprehensive analysis.

The Role of Novel Transcatheter Procedures in Patients With Congenital Heart Disease

The development of percutaneous structural interventions in patients with acquired heart disease is happening at an exponential rate, and some of this technology is being used to treat patients with congenital heart disease. This review describes the pathophysiology of valvular abnormalities specific to congenital heart disease and discusses the application of structural procedures in this population. Although the overall experience has been encouraging, especially in high-risk patients, this article will highlight the reasons that a cautious approach to adoption of this technology is necessary in these patients.