Surgical aortic valvotomy in infancy: impact of leaflet morphology on long-term outcomes

Neonates and Infants with Left Heart Obstruction and Borderline Left Ventricle Undergoing Biventricular Repair: What Do We Know about Long-Term Outcomes? A Critical Review

BACKGROUND

The decision to perform biventricular repair (BVR) in neonates and infants presenting with either single or multiple left ventricle outflow obstructions (LVOTOs) and a borderline left ventricle (BLV) is subject to extensive discussion, and limited information is known regarding the long-term outcomes. As a result, the objective of this study is to critically assess and summarize the available data regarding the prognosis of neonates and infants with LVOTO and BLV who underwent BVR.

METHODS

In February 2023, we conducted a review study with three different medical search engines (the National Library of Medicine, Science Direct, and Cochrane Library) for Medical Subject Headings and free text terms including "congenital heart disease", "outcome", and "borderline left ventricle". The search was refined by adding keywords for "Shone's complex", "complex LVOT obstruction", "hypoplastic left heart syndrome/complex", and "critical aortic stenosis".

RESULTS

Out of a total of 51 studies, 15 studies were included in the final analysis. The authors utilized heterogeneous definitions to characterize BLV, resulting in considerable variation in inclusion criteria among studies. Three distinct categories of studies were identified, encompassing those specifically designed to evaluate BLV, those focused on Shone's complex, and finally those on aortic stenosis. Despite the challenges associated with comparing data originating from slightly different cardiac defects and from different eras, our results indicate a favorable survival rate and clinical outcome following BVR. However, the incidence of reintervention remains high, and concerns persist regarding residual pulmonary hypertension, which has been inadequately investigated.

CONCLUSIONS

The available data concerning neonates and infants with LVOTO and BLV who undergo BVR are inadequate and fragmented. Consequently, large-scale studies are necessary to fully ascertain the long-term outcome of these complex defects.

Outcomes in neonatal critical and non-critical aortic stenosis: a retrospective cohort study

OBJECTIVE

To compare long-term survival, reinterventions and risk factors using strict definitions of neonatal critical and non-critical valvular aortic stenosis (VAS).

DESIGN

A nationwide retrospective study using data from patient files, echocardiograms and the Swedish National Population Registry.

SETTING AND PATIENTS

All neonates in Sweden treated for isolated VAS 1994-2018. We applied the following criteria for critical aortic stenosis: valvular stenosis with duct-dependent systemic circulation or depressed left ventricular function (fractional shortening ≤27%). Indication for treatment of non-critical VAS was Doppler mean gradient >50 mm Hg.

MAIN OUTCOME MEASURES

Short-term and long-term survival, aortic valve reinterventions need of valve replacements, risk factors for reintervention and event-free survival.

RESULTS

We identified 65 patients with critical VAS and 42 with non-critical VAS. The majority of the neonates were managed by surgical valvotomy. Median follow-up time was 13.5 years, with no patients lost to follow-up. There was no 30-day mortality. Long-term transplant-free survival was 91% in the critical stenosis group and 98% in the non-critical stenosis group (p=0.134). Event-free survival was 40% versus 67% (p=0.002) in the respective groups. Median time from the initial treatment to reintervention was 3.6 months versus 3.9 years, respectively (p=0.008).

CONCLUSIONS

Critical VAS patients had significantly higher need for reintervention during the first year of life, lower event-free survival and lower freedom from aortic valve replacement at age ≥18 years, compared with neonates with non-critical stenosis.

Aortic Valve Repair in Neonates With Aortic Stenosis and Reduced Left Ventricular Function

This study assessed outcomes of neonatal aortic valve (AoV) repair in presumed high-risk patients with depressed left ventricular (LV) function. A retrospective analysis of all neonates who underwent isolated AoV repair for severe aortic stenosis (AS) was performed. Patients with moderate or severe LV dysfunction were compared to those with normal or mild LV dysfunction. From 1980-2021, 43 neonates underwent isolated AoV repair for AS. Of these, 16 patients (37.2%) had ≥moderate LV dysfunction. Mean LV ejection fraction (EF) was 32.8 ± 9.1%. Valve morphology was mostly unicuspid (68.75%, 11/16). Median age at surgery was 6.5 days (IQR 1-17.5). An optimal repair result with ≤mild AS or aortic regurgitation was achieved in 75% (12/16). There was no early death. One patient (6.25%) required postoperative extracorporeal membrane oxygenation (ECMO) support for 3 days. LVEF improved after surgery to 56.4 ± 12.6% before discharge (P < 0.0001) and normalized in 87.5% (14/16) with a median time of 6.4 days (IQR 3.4-39). Freedom from AoV reoperation was 45.1% (95%CI 17.9-69.3%) and 27.1% (95%CI 6.8-53%) at 5 and 10 years, respectively. Freedom from AoV replacement was 59% (95%CI 27-80.8%) and 31.4% (95%CI 6-62.2%) at 5 and 10 years, respectively. While survival was similar, freedom from AoV reoperation and replacement tended to be lower compared to neonates with preserved LVEF. AoV repair was associated with a low incidence of postoperative ECMO and mortality. LV function normalized after relief of obstruction in most patients before discharge. Late reoperation remained common for those with severely dysplastic valves.

Balloon Valvuloplasty for Congenital Aortic Stenosis: Experience at a Tertiary Center in a Developing Country

Background

Aortic valve stenosis accounts for 3–6% of congenital heart disease. Balloon aortic valvuloplasty (BAV) is the preferred therapeutic intervention in many centers. However, most of the reported data are from developed countries.

Materials and Methods

We performed a retrospective single-center study involving consecutive eligible neonates and infants with congenital aortic stenosis admitted for percutaneous BAV between January 2005 and January 2016 to our tertiary center. We evaluated the short- and mid-term outcomes associated with the use of BAV as a treatment for congenital aortic stenosis (CAS) at a tertiary center in a developing country. Similarly, we compared these outcomes to those reported in developed countries.

Results

During the study period, a total of thirty patients, newborns (n = 15) and infants/children (n = 15), underwent BAV. Left ventricular systolic dysfunction was present in 56% of the patients. Isolated AS was present in 19 patients (63%). Associated anomalies were present in 11 patients (37%): seven (21%) had coarctation of the aorta, two (6%) had restrictive ventricular septal defects, one had mild Ebstein anomaly, one had Shone's syndrome, and one had cleft mitral valve. BAV was not associated with perioperative or immediate postoperative mortality. Immediately following the valvuloplasty, a more than mild aortic regurgitation was noted only in two patients (7%). A none-to-mild aortic regurgitation was noted in the remaining 93%. One patient died three months after the procedure. At a mean follow-up of 7 years, twenty patients (69%) had more than mild aortic regurgitation, and four patients (13%) required surgical intervention. Kaplan–Meier freedom from aortic valve reintervention was 97% at 1 year and 87% at 10 years of follow-up.

Conclusion

Based on outcomes encountered at a tertiary center in a developing country, BAV is an effective and safe modality associated with low complication rates comparable to those reported in developed countries.

Surgical Valvotomy Versus Balloon Valvuloplasty for Congenital Aortic Valve Stenosis: A Systematic Review and Meta-Analysis

BACKGROUND

Optimal initial treatment for congenital aortic valve stenosis in children remains unclear between balloon aortic valvuloplasty (BAV) and surgical aortic valvotomy (SAV).

METHODS AND RESULTS

We performed a contemporary systematic review and meta-analysis to compare survival in children with congenital aortic valve stenosis. Secondary outcomes included frequency of at least moderate regurgitation at hospital discharge as well as rates of aortic valve replacement and reintervention. Single- and dual-arm studies were identified by a search of PubMed (Medline), Embase, and the Cochrane database. Overall 2368 patients from 20 studies were included in the analysis, including 1835 (77%) in the BAV group and 533 (23%) in the SAV group. There was no difference between SAV and BAV in hospital mortality (OR=0.98, 95% CI 0.5-2.0, P=0.27, I(2)=22%) or frequency of at least moderate aortic regurgitation at discharge (OR=0.58, 95% CI 0.3-1.3, P=0.09, I(2)=54%). Kaplan-Meier analysis showed no difference in long-term survival or freedom from aortic valve replacement but significantly more reintervention in the BAV group (10-year freedom from reintervention of 46% [95% CI 40-52] for BAV versus 73% [95% CI 68-77] for SAV, P<0.001). Results were unchanged in a sensitivity analysis restricted to infants (<1 year of age).

CONCLUSIONS

Although higher rates of reintervention suggest improved outcomes with SAV, indications for reintervention may vary depending on initial intervention. When considering the benefits of a less-invasive approach, and clinical equipoise with respect to more clinically relevant outcomes, these findings support the need for a randomized controlled trial.

The mid-term outcome of primary open valvotomy for critical aortic stenosis in early infancy - a retrospective single center study over 18 years

Background

The objective of this study was to examine early and long-term results of surgical aortic valvotomy in neonates and infants aged less than four months and to identify predictors of outcome.

Methods

Between August 1994 and April 2012, 83 consecutive patients younger than 4 months of age underwent open heart valvotomy for critical aortic stenosis in our institution. Median age was 17 days (range 0-111 days). We examined clinical records to establish determinants of outcome and illustrate long-term results.

Results

Fifty-six patients (67 %) were neonates. Associated cardiac malformations were found in 24 patients (29 %), including multilevel left heart obstruction in 5. The median follow-up was 4.2 years. The time-related survival rate was 87 and 85 % at 5 and 15 years, respectively. The time-related survival without reintervention was respectively 51, 35 and 18 % at 5, 10 and 15 years. The time-related survival without aortic valve replacement was respectively 67, 54 and 39 % at 5, 10 and 15 years. Ventricular dysfunction (p = 0.04), delayed sternal closure (p = 0.007), endocardial fibroelastosis (p = 0.02) and low z-score of the aortic annulus (p = 0.04) were found predictors of global mortality. Ventricular dysfunction (p = 0.01) and endocardial fibroelastosis (p = 0.04) were found predictors of reintervention.

Conclusions

The experience, in our center, on the management of critical aortic stenosis, shows a low early and late mortality, but the aortic valvotomy is a palliative procedure and we see unfortunately a high rate of reintervention among which the aortic valve replacement. These results suggest to reconsider the use of aortic balloon valvotomy, and particularly for the neonates with a low cardiac output in order to avoid the myocardial stress and the neurological injury due to the cardiopulmonary bypass.

Neonatal Aortic Stenosis Is a Surgical Disease

Neonates with critical aortic stenosis represent a challenging group of patients with severe obstruction at a valvar level and with symptoms of heart failure. If biventricular repair is chosen, open valvotomy (OV) has been firmly established as the most effective initial treatment. In comparison with blind ballooning, OV, with exact splitting of fused commissures and shaving of obstructing nodules, can produce a better valve with a maximum valve orifice, without causing regurgitation. Thus, predictable and consistent early and longer-lasting results in any type of valve morphology are provided. Clearly superior results can be achieved in a tricuspid valve arrangement. OV not only offers a high survival benefit in the long run, but also a high quality of life, by minimizing re-interventions and preserving the native aortic valve in the majority of patients.

Is Aortic Valve Leaflet Morphology Predictive of Outcome in Pediatric Aortic Valve Stenosis?

BACKGROUND

Initial palliative treatment of congenital aortic valve stenosis consists of either surgical commissurotomy or transcatheter balloon valvuloplasty. The basis for selection of primary approach usually is ill defined. It was hypothesized that aortic valve characteristics may be helpful in directing choice of intervention. This study assesses the impact of valve morphology on time to reintervention after catheter- or surgical-based therapy.

METHODS

A retrospective review of preprocedural echocardiographic aortic outflow characteristics was compared with outcomes of primary surgical or balloon valve interventions. Characteristics studied included (1) annular dimension; (2) leaflet number; (3) leaflet excursion; and (4) degree of leaflet coaptation. Patients included those <20 years with a primary diagnosis of aortic stenosis (AS) and no other hemodynamically significant lesions at our institutions from 2000 to 2011. A total of 102 patients were included, 31 classified as having critical and 71 as having noncritical aortic stenosis. Of the patients, 79 were male, and 50 underwent primary catheter intervention. Echo parameters were compared with procedural outcome as defined by death or need for reintervention. Receiver operator curves were utilized to determine the point within each morphologic feature where the greatest difference occurred. This was utilized as the distinguishing point within each the morphologic group. Analysis was conducted separately for critical and noncritical aortic stenosis.

RESULTS

Kaplan-Meier analysis demonstrated no significant difference in time to reintervention or death whether initial palliation consisted of surgical commissurotomy or balloon valvuloplasty with respect to any of the morphologic characteristics studied.

CONCLUSION

Patients with AS do equally well with surgical commissurotomy or balloon valvuloplasty as initial palliation. This holds true for those with either critical or noncritical aortic stenosis. Valve morphology did not help in selection of initial palliative strategy. Current technologies should enable an improved selection of initial palliative approach through thoughtful, randomized trials.

Neonatal aortic stenosis

Neonatal aortic stenosis is a complex and heterogeneous condition, defined as left ventricular outflow tract obstruction at valvular level, presenting and often requiring treatment in the first month of life. Initial presentation may be catastrophic, necessitating hemodynamic, respiratory and metabolic resuscitation. Subsequent management is focused on maintaining systemic blood flow, either via a univentricular Norwood palliation or a biventricular route, in which the effective aortic valve area is increased by balloon dilation or surgical valvotomy. In infants with aortic annular hypoplasia but adequately sized left ventricle, the Ross-Konno procedure is also an attractive option. Outcomes after biventricular management have improved in recent years as a consequence of better patient selection, perioperative management and advances in catheter technology. Exciting new developments are likely to significantly modify the natural history of this disorder, including fetal intervention for the salvage of the hypoplastic left ventricle; 3D echocardiography providing better definition of valve morphology and aiding patient selection for a surgical or catheter-based intervention; and new transcutaneous approaches, such as duel beam echo, to perforate the valve.

Outcome of Surgical Commissurotomy for Aortic Valve Stenosis in Early Infancy

BACKGROUND

The method of treatment of aortic valve stenosis in early infancy is still controversial. This study was performed to evaluate short-term and long-term outcome in our center during a 14-year period.

METHODS

Between 1991 and 2004, 64 consecutive patients younger than 3 months old underwent open surgical commissurotomy because of aortic valve stenosis. Median age was 18 days (range, 1 to 79 days), and median weight was 3.6 kg (range, 1.9 to 6.7 kg). Left ventricular function was good in 44 patients (69%), depressed in 12 (19%), and poor in 8 (12%). The study ended in July 2005. Median follow-up time was 4.1 years (range, 0.4 to 13.6 years).

RESULTS

The 30-day mortality was 3 of 64 patients and late mortality was 3 of 61, and the respective mortality in patients younger than 1 month old was 2 of 41 and 2 of 39. There was no early mortality after 1993 and no late mortality after 1999. Thirteen patients required reoperation. Median time to reoperation was 4.3 years (range, 0.2 to 11.3 years) and to aortic valve replacement (7 Ross and 1 homograft) was 6.9 years (range, 1.6 to 9.7 years). At the last follow-up, all had good left ventricular function and 57 of 58 had an ability index of 1.

CONCLUSIONS

Surgical commissurotomy for aortic valve stenosis during the first 3 months of life can be done with low mortality and morbidity. The risk for early recurrent stenosis or regurgitation is low, and the need for aortic valve replacement can, in most cases, be delayed until the child is older. The long-term functional ability is excellent.

Neonatal Surgical Aortic Commissurotomy: Predictors of Outcome and Long-Term Results

BACKGROUND

The objective of this study was to review our institutional experience concerning neonatal aortic commissurotomy and to identify predictors of outcome.

METHODS

From January 1, 1990, to January 1, 2005, 65 neonates were referred for critical aortic stenosis. Among these 36 consecutive patients underwent surgical valvotomy by the same surgeon and 16 patients had balloon valvotomy. We examined clinical records to establish determinants of outcome and illustrate long-term results.

RESULTS

In the surgical group 6 patients had nonstenotic parachute mitral valve, 6 had aortic coarctation, 13 had endocardial fibroelastosis; and 15 had depressed fractional shortening. In the balloon valvotomy group most infants had associated mitral stenosis (n = 7), small aortic annulus (n = 5), multiple anomalies (n = 2), endocardial fibroelastosis (n = 9), and depressed fractional shortening (n = 13). In the surgical group global mortality was 19%; 47% in infants with depressed fractional shortening and 0% in infants with normal fractional shortening. Mortality in the balloon valvotomy group was 56%. Low fractional shortening, low mean aortic gradient, endocardial fibroelastosis, and small aortic annulus were associated with fatal outcome. In the surgical group 6 patients needed Ross operation at a median interval of 4 years from commissurotomy. In the balloon valvotomy group 3 patients needed early mitral replacement and 5 aortic valve surgery. At a median follow-up of 6 years, all children are in New York Heart Association class I, all have a normal ventricular function, 2 have aortic restenosis, and 5 have at least moderate aortic incompetence.

CONCLUSIONS

In a selected population of neonates with isolated aortic stenosis, surgical valvotomy offers an excellent long-term outcome to patients with a normokinetic left ventricle, while patients with a hypokinetic left ventricle have a poor outcome. Balloon valvotomy offers poor results when performed in patients with complex anomalies.

Current treatments for congenital aortic stenosis

PURPOSE OF REVIEW

Congenital valvar aortic stenosis is a challenging disease that often requires repeated palliative procedures. Stenosis can range from mild and asymptomatic, not requiring intervention, to severe, as seen in hypoplastic left heart syndrome. New advances such as fetal balloon valvuloplasty, improvements in the Ross technique, and long-term studies of trans-catheter balloon valvuloplasty and surgical valvotomy warrant a review of the outcomes and optimal timing of the various interventions.

RECENT FINDINGS

Fetal balloon valvuloplasty has shown promise. Despite some mortality and morbidity, some fetuses are showing significant growth in left ventricular structures, allowing biventricular repair. In neonates and infants with congenital aortic stenosis, excellent initial results are obtained with trans-catheter balloon valvuloplasty, although stenosis resistant to further balloon dilation or regurgitation may develop, necessitating surgical intervention. Midterm results from the Ross procedure are encouraging, demonstrating low rates of mortality, aortic insufficiency and re-intervention. Stenosis of the pulmonary allograft may be inevitable, and recent long-term follow-up suggests an increase in aortic insufficiency.

SUMMARY

While availability of fetal balloon valvuloplasty is limited, it has promise for promoting in-utero left ventricle growth and improving function. The optimal procedure for infants and neonates is trans-catheter balloon valvuloplasty. For older patients, the Ross procedure is the repair of choice, although more long-term studies are needed to assess the natural course of the autograft. Outcomes should improve with advances in pulmonary allografts.