Changes in left atrioventricular valve geometry after surgical repair of complete atrioventricular canal

Staged repair for complete atrioventricular septal defect in patients weighing less than 4.0 kg

OBJECTIVE

This study compared the mortality, left atrioventricular valve-related reoperation, and left atrioventricular valve competence in symptomatic neonates and small infants who underwent staged repair incorporating pulmonary artery banding or primary repair for complete atrioventricular septal defect.

METHODS

Patients weighing less than 4.0 kg at the time of undergoing staged (n = 37) or primary (n = 23) repair for balanced complete atrioventricular septal defect between 1999 and 2022 were reviewed. The mean follow-up period was 9.1 years. Freedom from moderate or greater left atrioventricular valve regurgitation was estimated with the Kaplan-Meier method.

RESULTS

The staged group included smaller children (median weight, 2.9 vs 3.7 kg) and a higher proportion of neonates (41% vs 4%). All patients in the staged group survived pulmonary artery banding and underwent intracardiac repair (median weight, 6.8 kg). After pulmonary artery banding, the severity of left atrioventricular valve regurgitation improved in 10 of 12 patients (83%) without left atrioventricular valve anomaly who had mild or greater left atrioventricular valve regurgitation and a left atrioventricular valve Z score greater than 0. Although survival and freedom from left atrioventricular valve-related reoperation at 15 years (P = .195 and .602, respectively) were comparable between the groups, freedom from moderate or greater left atrioventricular valve regurgitation at 15 years was higher in the staged group (P = .026).

CONCLUSIONS

Compared with primary repair, staged repair for complete atrioventricular septal defect in children weighing less than 4.0 kg resulted in comparable survival and reoperation rates and better left atrioventricular valve competence. Pulmonary artery banding may mitigate secondary left atrioventricular valve regurgitation unless a structural valve abnormality exists. Selective deferred intracardiac repair beyond the neonatal and small-infancy period may still play an important role in low-weight patients.

Mitral regurgitation outcomes after transcatheter atrial septal defect closure

BACKGROUND

Worsening mitral regurgitation (MR) is a complication of intervention for atrial septal defect (ASD). Little is known about mitral valve (MV) characteristics associated with worsening MR. We aimed to elucidate MR outcomes and predictors of worsening MR after transcatheter ASD closure.

METHODS

We analyzed changes in MR from prior to transcatheter ASD closure to 6 months after the procedure and predictors of worsening MR via baseline transthoracic echocardiography in 238 patients (64.7% females; mean age, 53 ± 22 years).

RESULTS

Worsening MR was defined as worsening to moderate in patients with less than or equal to mild MR at baseline or vena contracta width increasing of ≥2 mm by 6-month follow-up in patients with moderate MR. Worsening MR was observed in 29 patients (12.2%). The associated echocardiographic findings were pseudoprolapse, hamstringing, stiffness, and anteroposterior and intercommissural mitral annulus diameter in the univariable logistic regression analysis (all P < 0.05). Multivariable analysis after adjusting for age; long-standing persistent atrial fibrillation; and ASD size showed that models combining MV leaflet findings such as pseudoprolapse or hamstringing, or anterior leaflet stiffness with the ratio of the sum of anterior and posterior leaflet lengths to intercommissural mitral annulus diameter were statistically significant for predicting worsening MR (R2 = 0.393, P < 0.001 and R2 = 0.385, P < 0.001, respectively).

CONCLUSIONS

Worsening MR after transcatheter ASD closure might depend on MV leaflet findings and annulus size in patients with long-standing persistent atrial fibrillation.

Echocardiographic Evaluation of Postoperative Coaptation Geometry of Left AV Valve in Complete Atrioventricular Septal Defect

Background:

We sought to determine the difference in geometric parameters in the left atrioventricular valve (LAVV) postoperative complete atrioventricular septal defect (CAVSD) compared to the normal heart, and the correlation between geometric and functional parameters for detecting the mechanism of LAVV regurgitation (LAVVR) in CAVSD.

Methods:

LAVV geometric parameters based on complete and acceptable quality echocardiograms of 18 patients with repaired CAVSD compared with 17 normal controls. LAVVR severity was also quantified by indexed vena contracta (I-VC) (mm) and % jet area/left atrium area (% Jet/LA), and the correlation with LAVV parameters in the CAVSD group was investigated.

Results:

In the CAVSD group, the posterior closing angle (Pc) was nearly the same as the anterior closing angle (Ac), yet in the normal heart, the Pc angle was double the Ac angle. The anterior opening angle (Ao) and posterior-to-anterior leaflet diameter ratio (a/p) in the CAVSD group was also significantly smaller. The CAVSD group also had a shorter indexed coaptation length (I-CL) and indexed tenting height (I-TH). Displacement length (ΔD) differed completely between the CAVSD and Normal groups, and also showed a strong positive correlation to the functional parameters of LAVVR (% Jet/LA: r = .70, P = .02; I-VC: r = .60, P = .02).

Conclusions:

The parameters in this study were applicable to CAVSD AV valve coaptation characteristics. We introduced 2 novel measures that may provide important insights into the differences in geometry and performance of the LAVV in repaired CAVSD as compared to normal hearts.

Dynamic Annular Modeling of the Unrepaired Complete Atrioventricular Canal Annulus

BACKGROUND

Repair of complete atrioventricular canal (CAVC) is often complicated by atrioventricular valve regurgitation, particularly of the left-sided valve. Understanding the 3-dimensional (3D) structure of the atrioventricular canal annulus before repair may help to inform optimized repair. However, the 3D shape and movement of the CAVC annulus has been neither quantified nor rigorously compared with a normal mitral valve annulus.

METHODS

The complete annuli of 43 patients with CAVC were modeled in 4 cardiac phases using transthoracic 3D echocardiograms and custom code. The annular structure was compared with the annuli of 20 normal pediatric mitral valves using 3D metrics and statistical shape analysis (Procrustes analysis).

RESULTS

The unrepaired CAVC annulus varied in shape significantly throughout the cardiac cycle. Procrustes analysis visually demonstrated that the average normalized CAVC annular shape is more planar than the normal mitral annulus. Quantitatively, the annular height-to-valve width ratio of the native left CAVC atrioventricular valve was significantly lower than that of a normal mitral valve in all systolic phases (P < .001).

CONCLUSIONS

The left half of the CAVC annulus is more planar than that of a normal mitral valve with an annular height-to-valve width ratio similar to dysfunctional mitral valves. Given the known importance of annular shape to mitral valve function, further exploration of the association of 3D structure to valve function in CAVC is warranted.

Left Valvar Morphology Is Associated With Late Regurgitation in Atrioventricular Canal Defect

BACKGROUND

Left atrioventricular valve regurgitation (LAVVR) after atrioventricular canal (AVC) repair remains a significant cause of morbidity. Papillary muscle arrangement may be important. To investigate the implications of left mural leaflet morphology, we examined anatomic characteristics of the LAVV to determine possible associations with postoperative LAVVR.

METHODS

All patients with biventricular AVC repair at our institution between January 1, 2011, and December 31, 2016, with necessary imaging were retrospectively reviewed. We assessed papillary muscle structure and novel measures of the left mural leaflet from preoperative echocardiograms and the degree of LAVVR from the first and last available follow-up echocardiograms. Associations with degree of early and late postoperative LAVVR were assessed with t tests, analysis of variance, or χ² or Fisher exact tests, and multivariable logistic regression.

RESULTS

There were 58 of 156 patients (37%) with significant (moderate or severe) early postoperative LAVVR, and 30 of 93 (32%) had significant LAVVR after 6 or more months. Fewer patients with closely spaced or asymmetric papillary muscles had moderate or severe late LAVVR vs those with widely spaced papillary muscles (17% vs 40%, P = .019). Controlling for weight at operation, genetic syndromes, and bypass time, widely spaced papillary muscles increased the odds ratio for late LAVVR to 3.6 (P = .026). Larger mural leaflet area was also associated with late LAVVR on univariable (P = .019) and multivariable (P = .023) analyses. One-third of patients with significant late LAVVR had no significant early postoperative regurgitation.

CONCLUSIONS

Mural leaflet and papillary muscle anatomy are associated with late LAVVR after AVC repair. Late regurgitation can develop in the absence of early LAVVR, suggesting different mechanisms.

A Growth-Accommodating Implant for Paediatric Applications

Medical implants of fixed size cannot accommodate normal tissue growth in children, and often require eventual replacement or in some cases removal, leading to repeated interventions, increased complication rates and worse outcomes. Implants that can correct anatomic deformities and accommodate tissue growth remain an unmet need. Here, we report the design and use of a growth-accommodating device for paediatric applications that consists of a biodegradable core and a tubular braided sleeve, with inversely related sleeve length and diameter. The biodegradable core constrains the diameter of the sleeve, and gradual core degradation following implantation enables sleeve and overall device elongation in order to accommodate tissue growth. By using mathematical modeling and ex vivo experiments using harvested swine hearts, we demonstrate the predictability and tunability of the behavior of the device for disease- and patient-specific needs. We also used the rat tibia and the piglet heart valve as two models of tissue growth to demonstrate that polymer degradation enables device expansion and growth accommodation in vivo.

Mid-term outcome with pericardial patch augmentation for redo left atrioventricular valve repair in atrioventricular septal defect†

OBJECTIVES

Recurrent left atrioventricular valve (LAVV) regurgitation after atrioventricular septal defect (AVSD) repair is a difficult technical issue. This study exposes the various techniques successively employed to repair the recurrent LAVV regurgitation and their different outcomes. Emphasis however will be put on the new technique used in our unit called cleft patch augmentation, which has been used continuously since 1998 in the anatomical context of normal papillary muscles (NPMs).

METHODS

This is a retrospective follow-up study using a Cox regression model for risk analyses from November 1991 to July 2008, including 45 patients who underwent reoperation for LAVV regurgitation after AVSD repair. Of those, 3 patients were lost to follow-up; therefore, 42 patients were included in the study. With regard to the AVSD morphology, there were partial AVSD in 12, complete AVSD in 30.

RESULTS

Age at the primary valve repair was 1.5 ± 2.1 years and the time span to the reoperation was 7.1 years in median (0.41-12.3 years). Age at the first reoperation was 10.1 ± 6.8 years. Median follow-up after the reoperation was 7.4 years. Three patients died in the follow-up period. Freedom from second reoperation at 10 years was 72.8% [59.5-89.0% of 95% confidence interval (CI)]. Of 37 patients with NPMs, freedom from reoperation at 10 years was 59.4% (37.2-94.7% 95% CI) in cleft closure group whereas, in the cleft patch augmentation group, it was 92.3% (78.9-100% 95% CI) (P = 0.04). Five patients required valve replacement.

CONCLUSIONS

Surgical result for the redo LAVV repair had good outcomes. In the NPM group, the cleft patch augmentation technique had better results. Various techniques may have to be performed in combination according to the morphological features.

Echocardiographic features defining right dominant unbalanced atrioventricular septal defect: a multi-institutional Congenital Heart Surgeons' Society study

BACKGROUND

Definition and management of right dominant unbalanced atrioventricular septal defect (AVSD) remains challenging because unbalance entails a spectrum of left heart hypoplasia. Previous work has highlighted atrioventricular valve (AVV) index as a reasonable defining echocardiographic measure. We sought to assess which additional echocardiographic features might provide further characterization.

METHODS AND RESULTS

From a multi-institutional cohort of complete AVSD, 52 preoperative echocardiograms of patients with presumed right dominant unbalanced AVSD (based on AVV index) and 60 randomly selected preoperative echocardiograms from patients with presumed balanced AVSD were reviewed. Cluster analysis of echocardiographic variables was used to group patients with similar features. Discriminant function analysis was used to explore which variables differentiated these groups. Three groups were identified from the cluster analysis. Echocardiographic variables that differentiated these groups were right ventricle:left ventricle inflow angle, LV width/LV length, left AVV color diameter at smallest inflow, left AVV color diameter at annulus, right AVV overriding left atrium, and LV width. Based on procedures and outcomes, 1 group likely represented balanced patients, whereas 2 groups with similar outcomes likely represented unbalanced patients. The dominant differentiating echocardiographic variable between the 3 cluster groups was the right ventricle:LV inflow angle (partial R²=0.86), defined as the angle between the base of the right ventricle and LV free wall, using the crest of the ventricular septum as apex of the angle.

CONCLUSIONS

The angle of right ventricle/LV inflow and other surrogates of inflow may be important defining echocardiographic measures of right dominant unbalanced AVSD, although confirmation is needed.