Balancing Stenosis and Regurgitation During Mitral Valve Surgery in Pediatric Patients

Cleft closure and other predictors of contemporary outcomes after atrioventricular canal repair in patients with parachute left atrioventricular valve

OBJECTIVES

Parachute left atrioventricular valve (LAVV) complicates atrioventricular septal defect (AVSD) repair. We evaluate outcomes of AVSD patients with parachute LAVV and identify risk factors for adverse outcomes.

METHODS

We evaluated all patients undergoing repair of AVSD with parachute LAVV from 2012 to 2021. The primary outcome was a composite of time-to-death, LAVV reintervention and development of greater than or equal to moderate LAVV dysfunction (greater than or equal to moderate LAVV stenosis and/or LAVV regurgitation). Event-free survival for the composite outcome was estimated using Kaplan-Meier methodology and competing risks analysis. Cox proportional hazards regression was used to identify predictors of the primary outcome.

RESULTS

A total of 36 patients were included with a median age at repair of 4 months (interquartile range 2.3-5.5 months). Over a median follow-up of 2.6 years (interquartile range 1.0-5.6 years), 6 (17%) patients underwent LAVV reintervention. All 6 patients who underwent LAVV reintervention had right-dominant AVSD. Sixteen patients (44%) met the composite outcome, and all did so within 2 years of initial repair. Transitional AVSD (versus complete), prior single-ventricle palliation, leaving the cleft completely open and greater than or equal to moderate preoperative LAVV regurgitation were associated with a higher risk of LAVV reintervention in univariate analysis. In multivariate analysis, leaving the cleft completely open was associated with the composite outcome.

CONCLUSIONS

Repair of AVSD with parachute LAVV remains a challenge with a significant burden of LAVV reintervention and dysfunction in medium-term follow-up. Unbalanced, right-dominant AVSDs are at higher risk for LAVV reintervention. Leaving the cleft completely open might independently predict poor overall outcomes and should be avoided when possible.

CLINICAL TRIAL REGISTRATION NUMBER

IRB-P00041642.

Left atrioventricular valve repair after primary atrioventricular canal surgery: Predictors of durability

OBJECTIVE

Acute outcomes after atrioventricular canal defects (AVCD) surgery in the current era are excellent; yet despite surgical advances, ∼15% of patients require future left atrioventricular valve (LAVV) repair. Among patients with AVC who undergo LAVV repair after primary AVC surgery, we sought to characterize the durability of these repairs. Specifically, we aimed to determine predictors for reintervention following an LAVV repair in patients with repaired AVCD, with a focus on postoperative transesophageal echocardiography (TEE).

METHODS

We reviewed all patients undergoing LAVV repair (after a primary AVCD surgery) at Boston Children's Hospital between 2010 and 2020. Competing risk analysis was performed to evaluate cumulative incidence of LAVV reinterventions. Predictors of LAVV reintervention were evaluated using multivariable Cox regression.

RESULTS

A total of 137 LAVV repairs following primary AVCD surgery were performed in 113 patients. Median age and weight at LAVV repair were 25 months (interquartile range, 12-76 months) and 11.1 kg (interquartile range, 7.8-19.4 kg). Original anatomy was complete AVCD in 87 (63%), transitional AVCD in 27 (20%), and partial AVCD in 23 (17%) cases. Over a median follow-up of 12 months (interquartile range, 1.3 months-4 years), 47 (34%) of the LAVV repairs required LAVV reintervention. Reinterventions included a total of 27 LAVV re-repairs and 20 LAVV replacements. In multivariable analysis, age at LAVV repair younger than 72 months, partial AVCD anatomy, left ventricle dysfunction, mean LAVV stenosis gradient ≥5 mm Hg, and multiple jets of regurgitation on postoperative LAVV repair TEE were associated with LAVV reintervention. Grade of LAVV regurgitation on postoperative TEE was not an independent risk factor, but reintervention rates were high when residual LAVV stenosis gradient was ≥5 mm Hg and residual mild LAVV regurgitation was present on postoperative TEE (47%) and even higher when residual LAVV stenosis gradient was ≥5 mm Hg and LAVV regurgitation was greater than mild (73%).

CONCLUSIONS

Reintervention rates remain high for LAVV repairs that occur after primary AVCD surgery, particularly for patients with LAVV stenosis gradient ≥5 mm Hg and mild or greater LAVV regurgitation on postoperative TEE.

Outcomes of biventricular repair for shone's complex

BACKGROUND

Shone's complex is a rare lesion affecting the mitral valve (MV) and left ventricular outflow tract (LVOT). The objective of this study is to report the outcomes after Shone's complex repair, the growth of mitral and aortic valve and LVOT, and long-term survival.

METHODS

This retrospective study included all patients diagnosed with Shone's complex, who underwent biventricular repair. Data including patients' characteristics, type of the MV lesion and the associated lesions were collected. Patients were followed up regularly with echocardiography, and the changes in mitral and aortic valve z-score and LVOT z-score were recorded.

RESULTS

Thirty-seven patients were included in the study, the median age was 3.4 months, and 11 patients (30.6%) had pulmonary hypertension. The main procedure performed during the first surgical intervention was coarctation repair in 26 patients (70%). Twelve patients had MV repair, and five had MV replacement. Operative mortality occurred in 1 patient (2.7%), median follow up was 52 (25-75th percentile: 22-84) months. Survival at 1, 5, and 10 years was 94.4%, 90%, and 76.9%, respectively. Reoperation was required in 13 patients, mainly for LVOT repair (n = 8). Reoperation was significantly associated with associated aortic valve lesion (p = .044). The growth of the MV z-score was 0.35 per year; p < .001, aortic valve z-score 0.086 per year; p = 0.422, and the LVOT z-score was 0.53 per year; p = .01.

CONCLUSION

Biventricular repair of Shone's complex has good outcomes. Reoperation is frequently encountered, especially with low aortic valve z-score. The MV and LVOT have significant growth following Shone's complex repair.

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.

Outcome for Conservative Surgery for the Correction of Severe Mitral Valve Regurgitation in Children: A Single-Center Experience

Evolving reconstructive techniques have progressively become the preferred approach for treatment of pediatric mitral valve regurgitation. We present our experience in a cohort of patients undergoing surgical correction for severe mitral regurgitation. Fifty-five patients (age 1 month-18 years; median 5 years) were included in the present analysis. Different surgical techniques were used (posterior leaflet augmentation in 25, isolated cleft closure in 12, Alfieri-type procedure in 10, annuloplasty in 5, with artificial chordae in 2, and quadrangular resection with chordal transposition in 1). Follow-up time ranged from 1 to 192 months (median 38[IQR 12-54] months). Operative and follow-up mortality was 0%. Reintervention in the whole population occurred in 31% of patients. However, when first surgery was performed under 2 years of age (no = 17), reintervention reached nearly 50%. The degree of residual mitral regurgitation at follow-up remained stable after surgery, while a significant increase in mean transmitral gradient was observed over time (paired t test = 0.03). In multivariable Cox-regression analysis, post-surgical transmitral gradient was the only independent predictor for reintervention (p = 0.017; HR 2.4; 95%CI 1.2-5.1), after correcting for differences in age at surgery, type of reintervention, mitral annulus dimension, and BSA at the first surgery. ROC curve demonstrated that a post-surgical transmitral mean gradient value > 5 mmHg, was predictive for reintervention (AUC = 0.89; Youden index = 0.44). Our study suggests that the use of conservative technique strategy achieves satisfactory functional results in infants and children with severe MR, although the rate of reoperation in younger patients remains substantial. Post-operative moderate mitral stenosis was the strongest predictor for reoperation.

Surgical Atrioventricular Valve Replacement With Melody Valve in Infants and Children

Background Pediatric patients with atrioventricular valve disease have limited options for prosthetic valve replacement in sizes <15 mm. Based on successful experience with the stented bovine jugular vein graft (Melody valve) in the right ventricular outflow tract, the prosthesis has been modified for surgical valve replacement in pediatric patients with atrioventricular dysfunction with the intention of subsequent valve expansion in the catheterization laboratory as the child grows. Methods and Results A multicenter, retrospective cohort study was performed among patients who underwent atrioventricular valve replacement with Melody valve at 17 participating sites from North America and Europe, including 68 patients with either mitral (n=59) or tricuspid (n=9) replacement at a median age of 8 months (range, 3 days to 13 years). The median size at implantation was 14 mm (range, 9-24 mm). Immediately postoperatively, the valve was competent with low gradients in all patients. Fifteen patients died; 3 patients underwent transplantation. Nineteen patients required reoperation for adverse outcomes, including valve explantation (n=16), left ventricular outflow tract obstruction (n=1), permanent pacemaker implantation (n=1), and paravalvular leak repair (n=1). Twenty-five patients underwent 41 episodes of catheter-based balloon expansion, exhibiting a significant decrease in median gradient ( P<0.001) with no significant increase in grade of regurgitation. Twelve months after implantation, cumulative incidence analysis indicated that 55% of the patients would be expected to be free from death, heart transplantation, structural valve deterioration, or valve replacement. Conclusions The Melody valve is a feasible option for surgical atrioventricular valve replacement in patients with hypoplastic annuli. The prosthesis shows acceptable short-term function and is amenable to catheter-based enlargement as the child grows. However, patients remain at risk for mortality and structural valve deterioration, despite adequate early valvular function. Device design and implantation techniques must be refined to reduce complications and extend durability. Clinical Trial Registration URL: https://www.clinicaltrials.gov. Unique identifier: NCT02505074.

Atrioventricular valves dysplasia in a newborn

A newborn with prenatally diagnosed dysplasia of both atrioventricular valves presented after birth with signs and symptoms of low cardiac output, severe regurgitation of both mitral and tricuspid valves. This combination is as rare as challenging, since it regards both the timing and management of this complex cardiac malformation. We report an early surgical repair of both atrioventricular valves in a symptomatic newborn, which improved his clinical status and, so far, delayed valve replacement.

Assessment of the Melody valve in the mitral position in young children by echocardiography

OBJECTIVES

Mitral valve replacement (MVR) in young children is limited by the lack of small prostheses. Our institution began performing MVR with modified, surgically placed, stented jugular vein grafts (Melody valve) in 2010. We sought to describe key echocardiographic features for pre- and postoperative assessment of this novel form of MVR.

METHODS

The pre- and postoperative echocardiograms of 24 patients who underwent Melody MVR were reviewed. In addition to standard measurements, preoperative potential measurements of the mitral annulus were performed whereby dimensions were estimated for Melody sizing. A ratio of the narrowest subaortic region in systole to the actual mitral valve dimension (SubA:MV) was assessed for risk of postoperative left ventricular outflow tract obstruction (LVOTO).

RESULTS

Melody MVR was performed at a median of 8.5 months (5.6 kg) for stenosis (5), regurgitation (3), and mixed disease (16). Preoperatively, actual mitral z scores measured hypoplastic (median -3.1 for the lateral [lat] dimension; -2.1 for the anteroposterior [AP] dimension). The potential measurements often had normal z scores with fair correlation with intraoperative Melody dilation (ρ = 0.51 and 0.50 for lat and AP dimensions, respectively, both P = .01). A preoperative SubA:MV <0.5 was associated with postoperative LVOTO, which occurred in 4 patients. Postoperatively, mitral gradients substantially improved, with low values relative to the effective orifice area of the Melody valve. No patients had significant regurgitation or perivalvar leak.

CONCLUSIONS

Preoperative echocardiographic measurements may help guide intraoperative sizing for Melody MVR and identify patients at risk for postoperative LVOTO. Acute postoperative hemodynamic results were favorable; however, ongoing assessment is warranted.

Early and Mid-Term Outcome of Pediatric Congenital Mitral Valve Surgery

Background:

Congenital lesions of the mitral valve are relatively rare and are associated with a wide spectrum of cardiac malformations. The surgical management of congenital mitral valve malformations has been a great challenge.

Objectives:

The aim of this study was to evaluate the early and intermediate-term outcome of congenital mitral valve (MV) surgery in children and to identify the predictors for poor postoperative outcomes and death.

Patients and Methods:

In this retrospective study, 100 consecutive patients with congenital MV disease undergoing mitral valve surgery were reviewed in 60-month follow-up (mean, 42.4 ± 16.4 months) during 2008 - 2013. Twenty-six patients (26%) were under one-year old. The mean age and weight of the patients were 41.63 ± 38.18 months and 11.92 ± 6.12 kg, respectively. The predominant lesion of the mitral valve was MV stenosis (MS group) seen in 21% and MR (MR group) seen in 79% of the patients. All patients underwent preoperative two-dimensional echocardiography and then every six months after surgery

Results:

Significant improvement in degree of MR was noted in all patients with MR during postoperative and follow-up period in both patients with or without atrioventricular septal defect (AVSD) (P = 0.045 in patients with AVSD and P = 0.008 in patients without AVSD). Decreasing trend of mean gradient (MG) in MS group was statistically significant (P = 0.005). In patients with MR, the mean pulmonary artery pressure (PAP) had improved postoperatively (P < 0.001). Although PAP in patients with MV stenosis was reduced, this reduction was not statistically significant (P = 0.17). In-hospital mortality was 7%. Multivariate analysis demonstrated that age (P < 0.001), weight (P < 0.001), and pulmonary stenosis (P = 0.03) are strong predictors for mortality. Based on the echocardiography report at the day of discharge from hospital, surgical results were optimal (up to moderate degree for MR group and up to mild degree for MS group) in 85.7% of patients with MS and in 76.6% of patients with MR. Age (P = 0.002) and weight (P = 0.003) of patients are strong predictors for surgical success in multivariate analysis.

Conclusions:

Surgical repair of the congenital MV disease yields acceptable early and intermediate-term satisfactory valve function and good survival at intermediate-term follow-up. Strong predictors for poor surgical outcome and death were age smaller than 1 year, weight smaller or equal than 6 kg, and associated cardiac anomalies such as pulmonary stenosis.