Aortic valve reconstruction in the young infants and children

Physiological Ventricular Simulator for Valve Surgery Training

Surgical simulation is becoming increasingly important in training cardiac surgeons. However, there are currently no training simulators capable of testing the quality of simulated heart valve procedures under dynamic physiologic conditions. Here we describe a dynamic ventricular simulator, consisting of a 3D printed valve suspension chamber and a model 1423 Harvard apparatus pulsatile pump, which can provide close to physiologic hemodynamic perfusion of porcine aortic roots attached to the valve chamber for education and training in cardiac surgery. The simulator was validated by using it to test aortic valve leaflet repairs (n = 6) and aortic valve replacements (n = 3) that were performed by two trainees. Procedural success could be evaluated by direct visualization of the opening and closing valve, hemodynamic measurements and echocardiography. We conclude that, unlike other methods of simulation, this novel ventricular simulator is able to test the functional efficacy of aortic procedures under dynamic physiologic conditions using clinically relevant echocardiographic and hemodynamic outcomes. While validated for valve surgery, other potential applications include ascending aortic interventions, coronary re-implantation or catheter-based valve replacements.

Aortic valve neocuspidalization in paediatric patients with isolated aortic valve disease: early experience

OBJECTIVES

There is growing interest in the aortic valve (AV) neocuspidalization technique for the treatment of aortic valve disease (AVD). We report our medium-term results with this procedure performed in a paediatric patient population.

METHODS

Between July 2016 and May 2020, 22 patients with both congenital and acquired isolated AVD were treated with neocuspidalization. The primary outcome was progression of the preoperatively assessed AVD in the immediate postoperative course and at follow-up. Secondary outcome was freedom from reintervention by material used. Potential predictors of failure were analysed in relation to the primary outcome.

RESULTS

The median age at operation was 13.9 (interquartile range, 9.8-16.2) years, and the prevailing AV defect was stenosis in 10 cases (45%) and incompetence in 12 (55%). Pre-treated autologous pericardium was used in 13 patients whereas bovine pericardium in 9. Effective treatment of AV stenosis or regurgitation was achieved and remained stable over a median follow-up of 11.3 (4.7-21) months. Three patients required AV replacement at 4.9, 3.5 and 33 months. At follow-up, an upward trend of both median indexed vena contracta jet widths and aortic peak and mean gradients were recorded, the latter associated with a failure to grow the aortic annulus. Predictor of such outcome turned out to be the use of bovine pericardium. A significant inverse linear correlation between AV peak gradient at follow-up and preoperative aortic annular size (P = 0.008) was also demonstrated.

CONCLUSIONS

The Ozaki procedure is safe and effective in paediatric patients with AV disease. The use of heterologous pericardium should probably be minimized. Moreover, preoperative small aortic annuli should probably be promptly treated by means of an associated ring enlargement procedure.

Unicuspid aortic valve repair with bicuspidization in the paediatric population

OBJECTIVES

Aortic stenosis or regurgitation that requires operations in children often results from unicuspid valve morphology. In all paediatric patients with this anomaly, we have performed unicuspid valve repair by bicuspidization, creating a new commissure via adding patch material. This study reviewed our experience with this procedure.

METHODS

All patients with a unicuspid aortic valve who underwent bicuspidization at ≤18 years of age between 2003 and 2018 were evaluated. Autologous pericardium had initially been used for cusp augmentation. Since 2014, decellularized xenogeneic tissue or expanded polytetrafluoroethylene membrane has been applied.

RESULTS

There were 60 consecutive patients. The median operative age was 13 (1-18) years. Thirty patients had prior surgical or catheter valvuloplasties. Aortic regurgitation, aortic stenosis and their combination were present in 22, 11 and 27 patients, respectively. Autologous pericardium decellularized tissue and expanded polytetrafluoroethylene were used in 45, 11 and 4 patients, respectively, without intraoperative conversion to valve replacement. The overall survival was 96% at 10 years with 2 late deaths. Twenty patients underwent aortic valve reoperation due to patch degeneration (n = 11), suture dehiscence of the patch (n = 3), subaortic stenosis (n = 3) or other reasons (n = 3). Freedom from aortic valve reoperation was 73% and 50% at 5 and 10 years, respectively. Fifteen patients (25%) required valve replacement with pulmonary autograft (n = 14) or prosthesis (n = 1) 5.2 (0.2-13) years after bicuspidization at the age of 19 (10-32) years.

CONCLUSIONS

Bicuspidization is a safe and reproducible alternative to valve replacement with acceptable freedom from reoperation. It can serve as a bridge to valve replacement providing superior outcomes in adults.

Aortic Valve Neocuspidalization May Be a Viable Alternative to Ross Operation in Pediatric Patients

The aim of the study was to evaluate the medium-term results of aortic valve neocuspidalization according to Ozaki compared to Ross procedure for treatment of isolated aortic valve disease in pediatric age. Thirty-eight consecutive patients with congenital or acquired aortic valve disease underwent either Ozaki (n = 22) or Ross (n = 16) operation between 01/2015 and 05/2020. The primary outcome was progression of aortic valve disease and aortic ring and root dimension, whereas secondary outcome was freedom from reintervention or death by type of operation. Median age was 12.4 (8.8-15.8) years and the prevailing lesion was stenosis in 20 cases (52%) and incompetence in 18 (48%). One death occurred in the Ross group in the early postoperative period, while there were no deaths in the Ozaki group. Effective treatment of aortic valve stenosis or regurgitation occurred in both groups and remained stable over a median follow-up of 18.2 (5-32) months. In Ozaki group, 3 patients required aortic valve replacement at 4.9, 3.5, and 33 months, respectively. In Ross group, 1 patient required Melody pulmonary valve replacement, whereas none required aortic valve surgery. Finally, significantly higher aortic transvalvular gradient at follow-up was recorded in Ozaki group compared to Ross group. Overall, there was no significant difference in freedom from reoperation or death between the two groups. The medium-term outcome of Ozaki and Ross in pediatric patients is similar, despite an increased tendency of the former to develop aortic transvalvular gradient in the follow-up. Future larger multicenter studies with longer follow-up are warranted to confirm these results.

Modified Ozaki Procedure Including Annular Enlargement for Small Aortic Annuli in Young Patients

BACKGROUND

Aortic valve neocuspidization (AVNeo) (Ozaki procedure) has excellent midterm results in adults. Outcomes in patients with a small native aortic annulus are unknown. We report early outcomes in young patients with small native aortic valve annuli.

METHODS

Retrospective data of patients undergoing AVNeo between 2015 and 2019 were reviewed. Patients with native aortic annulus less than 21 mm undergoing 3-leaflet AVNeo were included.

RESULTS

A total of 51 patients were identified (median age 7.9 years; median weight 21 kg), and 80% patients were less than or equal to 12 years age. Preoperative indication was aortic regurgitation (AR) (n = 23), aortic stenosis (AS) (n = 22), or mixed AS and AR (n = 6). Baseline anatomy was quadricuspid (n = 1), tricuspid (n = 23), bicuspid (n = 15), or unicuspid (n = 12) valve. Preoperative peak gradient for AS and mixed AS and AR patients was 55.36 mm Hg. Median native annulus diameter was 17 mm; sinus and annular enlargements were required in 22 patients and 9 patients, respectively. Median intensive care unit and hospital length of stay were 2.0 days and 7.2 days, respectively. There were no reinterventions, and there was 1 hospital mortality unrelated to aortic valve. At discharge, 94% of patients had less than or equal to mild AR, and the median peak gradient was 18 mm Hg. At mean follow-up of 11.9 months, 80% and 82% of patients had less than moderate AR and AS, respectively. Three patients required surgical reintervention. In annular enlargement patients, mean annulus Z score remained greater than 0 at follow-up.

CONCLUSIONS

The Ozaki procedure has acceptable short-term results in young patients with small aortic annuli. A larger aortic annulus can be achieved with surgical annular enlargement. Long-term follow-up is necessary to determine late valve function and potential continued annular growth.

Congenital aortic and truncal valve reconstruction using the Ozaki technique: Short-term clinical results

OBJECTIVES

Aortic valve reconstruction (AVRec) with neocuspidization or the Ozaki procedure with complete cusp replacement for aortic valve disease has excellent mid-term results in adults. Limited results of AVRec in pediatric patients have been reported. We report our early outcomes of the Ozaki procedure for congenital aortic and truncal valve disease.

METHODS

A retrospective analysis was performed on all 57 patients with congenital aortic and truncal valve disease who had a 3-leaflet Ozaki procedure at a single institution from August 2015 to February 2019. Outcome measures included mortality, surgical or catheter-based reinterventions, and echocardiographic measurements.

RESULTS

Twenty-four patients had aortic regurgitation (AR), 6 had aortic stenosis (AS), and 27 patients had AS/AR. Two patients had quadricuspid valves, 26 had tricuspid, 20 had bicuspid, and 9 had unicusp aortic valves. Four patients had truncus arteriosus. Thirty-four patients had previous aortic valve repairs and 5 had replacements. Preoperative echocardiography mean annular diameter was 20.90 ± 4.98 cm and peak gradient for patients with AS/AR was 53.62 ± 22.20 mm Hg. Autologous, Photofix, and CardioCel bovine pericardia were used in 20, 35, and 2 patients. Eight patients required aortic root enlargement and 20 had sinus enlargement. Fifty-one patients had concomitant procedures. Median intensive care unit and hospital length of stay were 1.87 and 6.38 days. There were no hospital mortalities or early conversions to valve replacement. At discharge, 98% of patients had mild or less regurgitation and peak aortic gradient was 16.9 ± 9.5 mm Hg. Two patients underwent aortic valve replacement. At median follow-up of 8.1 months, 96% and 91% of patients had less than moderate regurgitation and stenosis, respectively.

CONCLUSIONS

The AVRec procedure has acceptable short-term results and should be considered for valve reconstruction in pediatric patients with congenital aortic and truncal valve disease. Longer-term follow-up is necessary to determine the optimal patch material and late valve function and continued annular growth.

Aortic valve neo-cuspidation using the Ozaki technique for acquired and congenital disease: where does this procedure currently stand?

The surgical treatment options for pediatric aortic valve disease are limited. The Ozaki procedure, which involves templated creation of new aortic valve leaflets, has proved to be a promising surgical technique. This review aims at elaborating the indications, technical intricacies, and outcomes of the aortic valve neo-cuspidization procedure (Ozaki procedure) in the pediatric population.

The great debate series: surgical treatment of aortic valve abnormalities in children

This article is the latest in an EJCTS series entitled 'The Great Debates'. We have chosen the topic of aortic valve (AoV) surgery in children, with a focus on infants and neonates. The topic was selected due to the significant challenges that AoV problems in the young may present to the surgical team. There are many areas of active controversy, despite the vast accumulated world experience. We have tried to incorporate many of these issues in the questions posed, not claiming to be all-inclusive. The individuals invited to this debate are experts in paediatric valve surgery, with broad and successful clinical experiences on multiple continents. We hope that the facts and opinions presented in this debate will generate interest and discussion and perhaps prove useful in decision-making for future complex valve cases.

Intraoperative Echocardiography for Congenital Aortic Valve Repair: Predictors of Early Reoperation

BACKGROUND

We sought to identify transesophageal echocardiography (TEE) predictors of early reoperation for recurrent aortic regurgitation (AR) after cardiopulmonary bypass (CPB) in patients undergoing repair for congenital aortic valve disease.

METHODS

We analyzed post-CPB TEEs in patients with congenital aortic valve disease undergoing repair for predominant AR. Case patients underwent reoperation for recurrent AR within 2 years, whereas control patients were free from reoperation for more than 3 years.

RESULTS

Case patients (n = 22; median time to reoperation 0.3 years) and control patients (n = 22; median freedom from reoperation ≥4.4 years) were similar for demographic characteristics, aortic dimensions, and preoperative AR grade. Among post-CPB TEE variables, univariate logistic regression analysis identified shorter coaptation height (odds ratio [OR] for 1-mm increase 0.72, 95% confidence interval [CI]: 0.54 to 0.95; p = 0.02), decreased ratio of coaptation height to annulus diameter (OR for a 5% decrease 1.37, 95% CI: 1.06 to 1.77; p = 0.02), and increased percentage difference (%diff) between longest and shortest coaptation lengths in a short-axis view (OR for 10% increase 1.84, 95% CI: 1.15 to 2.92; p = 0.01) as risk factors for early reoperation for recurrent AR. Multivariable analysis identified %diff in short-axis coaptation lengths as the strongest post-CPB TEE predictor (area under receiver operator curve = 0.743). The sensitivity and specificity of a %diff of 50% were 0.45 and 0.91, whereas a %diff of 30% had a sensitivity of 0.75 and specificity of 0.67.

CONCLUSIONS

Coaptation asymmetry, measured as increased %diff in short-axis coaptation lengths on post-CPB TEE, is associated with early reoperation for recurrent AR after congenital valve repair.

Valve-sparing aortic root replacement and remodeling with complex aortic valve reconstruction in children and young adults with moderate or severe aortic regurgitation

OBJECTIVES

The durability of valve-sparing aortic root procedures with aortic regurgitation due to leaflet disease is questioned. Here, we review our experience in combined aortic root and valve reconstruction in children and young adults.

METHODS

All valve-sparing aortic root procedures from 2000 to 2012 were reviewed, and patients with aortic valve repair beyond resuspension were included. Root procedures were classified as replacement with reimplantation, root remodeling, or aortic annular and sinotubular junction stabilization. The primary end point was structural valve deterioration, a composite of aortic valve reoperation and/or moderate or greater regurgitation at follow-up.

RESULTS

Thirty-four patients were included during the study period. The surgery consisted of reimplantation in 13 patients, remodeling in 16 patients, and annular and sinotubular junction stabilization in 5 patients. Valve repair consisted of leaflet procedures in 26 patients and subannular reduction in 15 patients. During a median follow-up of 4.2 months (range, 2 weeks-8 years), there were 5 reoperations for aortic valve replacement due to aortic regurgitation, and 2 patients presented with moderate or greater regurgitation. Freedom from structural valve deterioration was 70.1% ± 10.3% at 1 year and remained stable thereafter, although it was significantly worse in the reimplantation group (P = .039). A more severe degree of preoperative aortic regurgitation (P = .001) and smaller graft to aortic annulus ratio (P = .003) were predictors of structural valve deterioration.

CONCLUSIONS

Valve-sparing root and valve reconstruction can be done with low operative risk and allows valve preservation in most patients. These data should question the assumption that reimplantation is superior when associated with complex valve reconstruction.

Aortic Cusp Extension for Surgical Correction of Rheumatic Aortic Valve Insufficiency in Children

Surgical management of aortic insufficiency in the young is problematic because of the lack of an ideal valve substitute. Potential advantages of aortic valve repair include low incidences of thromboembolism and endocarditis, avoiding conduit replacements, the maintenance of growth potential, and improved quality of life. Aortic valve repair is still far from fulfilling the three key factors that have allowed the phenomenal development of mitral valve repair (standardization, reproducibility, and stable long-term results); however, techniques of aortic valve repair have been refined, and subsets of patients amenable to repair have been identified. We have focused on the oldest technique of aortic valve repair, cusp extension, focusing on children with rheumatic aortic insufficiency. Among 77 children operated from 2003 to 2007, there was one early death from ventricular failure and one late death from sudden cardiac arrhythmia. During a mean follow-up of 12.8 ± 5.9 years, there were 16 (20.5%) reoperations on the aortic valve, at a median of 3.4 years (range, 2 months to 18.3 years) from repair. Freedom from aortic valve reoperation was 96.2% ± 2.2% at 1 year, 94.9% ± 2.5% at 2 years, 88.5% ± 3.6% at 5 years, 81.7% ± 4.4% at 10 years, 79.7% ± 4.8% at 15 years, and 76.2% ± 5.7% at 20 years. Although aortic cusp extension is technically more demanding, it remains particularly more suitable in the context of evolving rheumatic aortic insufficiency in children with a small aortic annulus as a bridge surgical approach to late aortic valve replacement with a larger valvular prosthesis.

A simple method of aortic valve reconstruction with fixed pericardium in children

Aortic valve reconstruction with fixed pericardium may occasionally be very useful when treating children with aortic valve disease. This is because diseased aortic valves in children are sometimes too dysmorphic for simple repair without the addition of material, their annulus may be too small for a prosthesis, and the Ross operation may be precluded due to other congenital anomalies such as pulmonary valvar or coronary malformations. Such reconstruction is usually technically demanding and requires much precision. We describe a simple alternative method, which we have carried out in 3 patients, aged 1 week, 3 years and 12 years, respectively, with good early results.