Development of left atrioventricular valve regurgitation after correction of atrioventricular septal defect

Predictors of post-operative left atrioventricular valve regurgitation in pediatric patients with complete atrioventricular canal defects

BACKGROUND

In infants with complete atrioventricular canal (CAVC) defects, post-operative left atrioventricular valve regurgitation (LAVVR) is a known major cause of morbidity and mortality and a common indication for re-operation. However, there is scarce data to identify risk factors for poor outcomes. Our study aims to find echocardiographic characteristics that predict post-operative LAVVR at discharge and 1-year follow-up.

METHODS

Retrospective cohort study of patients with initial CAVC repair at our hospital who were followed for 1 year between 2013 and 2022. Patients with major co-morbid conditions were excluded. Serial echocardiograms were reviewed. Anatomic details, quantitative and qualitative measure of LAVVR including the number of regurgitant jets, regurgitant jet length and vena contracta width, and ventricular function were collected. The time points measured include pre-operative transthoracic echocardiogram (TTE), post-operative transesophageal echocardiogram (PO-TEE), routine protocol based post-operative day 1 (POD1) TTE, discharge TTE and 1-year post-operative (1yPO) TTE. Paired t-tests, chi-square analysis, and linear regression analysis were performed comparing measured variables to LAVVR outcomes.

RESULTS

Fifty-two patients were included; 92% had Trisomy 21. The majority were classified as Rastelli A (71%), others Rastelli C (29%). Only two patients had moderate or greater LAVVR pre-operatively. The mean age at repair was 125 ± 44 days. Pre-operative LAVVR was the only significant predictor of LAVVR severity at 1 year after backward stepwise regression. Of those with < moderate LAVVR on PO-TEE, 20% had worsening to ≥ moderate at discharge, but only 9% remained that way at 1 year. Of those with ≥ moderate LAVVR on PO-TEE, 40% improved to < moderate by 1 year. Two patients who worsened at 1 year, both secondary to likely cleft suture dehiscence. Only one patient required reoperation in the immediate post-operative period secondary to severe LAVVR due to suture dehiscence. Routine protocol-based POD1 echo did not have any association with altered outcomes.

CONCLUSION

Pre-operative LAVVR was the only significant predictor of LAVVR severity at 1 year. A significant percentage (40%) of patient with ≥ moderate LAVVR on PO-TEE improved to < moderate by 1 year. Furthermore, routine protocol-based POD1 echo did not have any association with altered outcomes.

Repair of the complete atrioventricular septal defect-impact of postoperative moderate or more regurgitation

OBJECTIVES

To study the risk factors for mortality, moderate or more left atrioventricular valve regurgitation (LAVVR) and reoperation after the surgical repair of complete atrioventricular septal defect (cAVSD) in a single centre.

METHODS

The current study is a retrospective review of patients who underwent surgical repair of cAVSD between 2000 and 2021. Patients with unbalanced ventricles not amenable to biventricular repair, double outlet right ventricle and malpositioned great arteries were excluded. The clinical predictors of outcome for end points were analysed with univariate and multivariable Cox regression analysis or Fine-Gray modelling for competing risks. Time-dependent end points were estimated using the Kaplan-Meier curve analysis and cumulative incidence curves.

RESULTS

The median follow-up time was 2.3 years. Among 220 consecutive patients were 10 (4.6%) operative and 21 late mortalities (9.6%). A total of 26 patients were identified to have immediate postoperative moderate or more regurgitation and 10 of them ultimately died. By multivariable analysis prematurity and having more than moderate regurgitation immediately after the operation were identified as predictors of overall mortality (P = 0.003, P = 0.012). Five- and ten-year survival rates were lower for patients with immediate postoperative moderate or more LAVVR {51.9% [confidence interval (CI): 27.5-71.7%]} when compared to patients without moderate or more regurgitation [93.2% (CI: 87.1-96.4%) and 91.3% (CI: 83.6-95.5%)].

CONCLUSIONS

The patients who undergo cAVSD repair remain subjected to a heavy burden of disease related to postoperative residual LAVVR. Immediate postoperative moderate or more LAVVR contributes significantly to overall mortality. Whether a second run of bypass can decrease this observed mortality should be investigated.

Long-term results following atrioventricular septal defect repair

BACKGROUND

Atrioventricular septal defects (AVSD) represent 4-7% of congenital cardiac malformations. Definitive early repair is favored over prior pulmonary artery banding and delayed definitive repair in many centers. The aim of this study was to analyze long-term outcomes following AVSD repair over a 21-year period.

METHODS

A total of 202 consecutive patients underwent surgical AVSD correction between June 1999 and December 2020. Surgery was performed using the double-patch technique. The study data were prospectively collected and retrospectively analyzed. Primary outcomes were In-hospital mortality and overall long-term freedom from reoperation.

RESULTS

Median age at operation was 120 days (IQR 94-150), median weight was 5.0 kg (4.2-5.3). None of the patients died within the first 30 postoperative days. In-hospital mortality was 0.5% (1/202 patients). Median follow-up was 57 months (11-121). Overall freedom from reoperation at 5, 10 and 15 years was 91.8%, 86.9% and 86.9%, respectively.

CONCLUSION

AVSD repair with the double-patch technique is a safe and effective procedure with good early postoperative outcomes and low long-term reoperation rates.

Modified single-patch repair for atrioventricular septal defects results in good functional outcomes in the absence of deep ventricular septal defects

OBJECTIVES

We compared 2-patch repair (TP) with modified single-patch repair (MSP) for complete atrioventricular septal defects and evaluated their effect on the left atrioventricular valve (LAVV) competence. We also identified risk factors for unfavorable functional outcomes.

METHODS

This retrospective study included 118 patients with complete atrioventricular septal defects who underwent intracardiac repair from 1998 to 2020 (MSP: 69; TP: 49). The median follow-up period was 10.4 years. The functional outcome of freedom from moderate or greater LAVV regurgitation (LAVVR) was estimated using the Kaplan-Meier method.

RESULTS

The hospital mortality was 1.7% (2/118) and late mortality was 0.8% (1/118). Eight patients required LAVV-related reoperation (MSP: 4; TP: 4) and none required left ventricular outflow tract-related reoperation. In the MSP group without LAVV anomaly, the receiver operating characteristic curve analysis revealed that the ventricular septal defect (VSD) depth was strongly associated with moderate or greater postoperative LAVVR, with the best cutoff at 10.9 mm. When stratified according to the combination of intracardiac repair type and VSD depth, the MSP-deep VSD (VSD depth >11 mm) group showed the worst LAVV competence among the 4 groups (P = .002). According to multivariate analysis, weight <4.0 kg, LAVV anomaly, and moderate or greater preoperative LAVVR were independent risk factors for moderate or greater postoperative LAVVR, whereas MSP was not a risk factor.

CONCLUSIONS

Postoperative LAVVR remains an obstacle to improved functional outcomes. MSP provides LAVV competence similar to TP unless deep VSD is present. The surgical approach should be selected on the basis of anatomical variations, specifically VSD depth.

Comparison of Intraoperative and Discharge Residual Lesion Severity in Congenital Heart Surgery

BACKGROUND

While the predischarge technical performance score (DC-TPS) is significantly associated with outcomes after congenital cardiac surgery, the utility of the intraoperative TPS (IO-TPS) remains unknown.

METHODS

This was a single-center retrospective review of consecutive patients who underwent congenital cardiac surgery from January 2011 to December 2019. Intraoperative and predischarge echocardiograms were used to assign IO-TPS and DC-TPS, respectively, for each index operation (class 1, no residua; class 2, minor residua; class 3, major residua). Anatomic modules identifying the principal residual lesion were assigned to all class 2/3 patients. Overall and module-specific TPS comparisons were made. Multivariable regression models with IO-TPS and DC-TPS as separate predictors of postoperative outcomes were compared.

RESULTS

Of 6201 patients, overall agreement between IO-TPS and DC-TPS was observed in 4251 patients (68.6%); scores were likelier to be worse at discharge (P < .001). Paired comparative analyses revealed that among patients with at least class 2 atrioventricular and semilunar valve residua, IO-TPS was likelier to worsen than improve (both P < .001). Class 3 patients had a higher risk of in-hospital/early mortality (IO-TPS: odds ratio, 7.5; 95% CI, 2.4-23; DC-TPS: odds ratio, 6.6; 95% CI, 3.0-15), postdischarge/late mortality (IO-TPS: hazard ratio [HR], 3.1, 95% CI, 1.3-7.1; DC-TPS: HR, 2.3; 95% CI, 1.2-4.4), and late unplanned reintervention (IO-TPS: HR, 2.8; 95% CI, 1.9-4.0; DC-TPS: HR, 3.4; 95% CI, 2.8-4.2) vs class 1 (all P < .05). IO- and DC-TPS models were equivalent fits for predicting early and late mortality; the latter was a marginally better fit for late reintervention.

CONCLUSIONS

IO-TPS and DC-TPS are both important adjuncts for quality improvement in congenital cardiac surgery.

Visualization and Quantification of the Unrepaired Complete Atrioventricular Canal Valve Using Open-Source Software

BACKGROUND

Repair of complete atrioventricular canal (CAVC) is often complicated by residual left atrioventricular valve regurgitation. The structure of the mitral and tricuspid valves in biventricular hearts has previously been shown to be associated with valve dysfunction. However, the three-dimensional (3D) structure of the entire unrepaired CAVC valve has not been quantified. Understanding the 3D structure of the CAVC may inform optimized repair.

METHODS

Novel open-source work flows were created in SlicerHeart for the modeling and quantification of CAVC valves on the basis of 3D echocardiographic images. These methods were applied to model the annulus, leaflets, and papillary muscle (PM) structure of 35 patients (29 with trisomy 21) with CAVC using transthoracic 3D echocardiography. The mean leaflet and annular shapes were calculated and visualized using shape analysis. Metrics of the complete native CAVC valve structure were compared with those of normal mitral valves using the Mann-Whitney U test. Associations between CAVC structure and atrioventricular valve regurgitation were analyzed.

RESULTS

CAVC leaflet metrics varied throughout systole. Compared with normal mitral valves, the left CAVC PMs were more acutely angled in relation to the annular plane (P < .001). In addition, the anterolateral PM was laterally and inferiorly rotated in CAVC, while the posteromedial PM was more superiorly and laterally rotated, relative to normal mitral valves (P < .001). Lower native CAVC atrioventricular valve annular height and annular height-to-valve width ratio before repair were both associated with moderate or greater left atrioventricular valve regurgitation after repair (P < .01).

CONCLUSIONS

It is feasible to model and quantify 3D CAVC structure using 3D echocardiographic images. The results demonstrate significant variation in CAVC structure across the cohort and differences in annular, leaflet, and PM structure compared with the mitral valve. These tools may be used in future studies to catalyze future research intended to identify structural associations of valve dysfunction and to optimize repair in this vulnerable and complex population.

Reoperations After Repair for Atrioventricular Septal Defects: >25 Years Experience at a Single Center

Our aim was to evaluate the total burden of reoperations after previous repair for atrioventricular septal defects, including long-term survival and identify risk factors for reoperation. All patients with surgical correction for atrioventricular septal defect (AVSD) 1993- 2020 underwent a follow-up in October 2020. Clinical data were obtained by retrospective review and evaluated with Kaplan-Meier and competing risk analysis. Of 477 patients who underwent initial repair, 53 patients (11.1%) underwent a total of 82 reoperations. The perioperative mortality at reoperation was 3.8% (2/53). There were no late deaths (0/51) during follow-up. In patients requiring reoperation for left atrioventricular valve regurgitation, a re-repair was performed in 90% (26/29) at first attempt. Estimated overall survival was 96.2 ± 2.6% (95% CI 91.2-100) in the Any reoperation group and 96.7 ± 0.9% (95% CI 94.9-98.5) in the No reoperation group at 20 years (P = 0.80). The cumulative incidence function of Any reoperation (with death as competing risk) was 13.0% (95% CI 9.4-16.5) at 20 years. Independent risk factors for Any reoperation included severe mitral regurgitation after primary repair (HR 40.7; 95% CI 14.9-111; P < 0.001). The risk of perioperative mortality in AVSD patients undergoing reoperation was low in the present study. Long-term survival was very good and not significantly different when compared to patients who did not need reoperation. Re-repair for left atrioventricular valve regurgitation was possible in most cases and showed long-term durability. Our data suggest that reoperations after primary repair of AVSD have very good long-term outcomes when performed at a high-volume pediatric cardiac surgery center.

Long-Term Outcome Up To 40 Years after Single Patch Repair of Complete Atrioventricular Septal Defect in Infancy or Childhood

Objectives  Patients with repaired complete atrioventricular septal defect (CAVSD) represent an increasing portion of grown-ups with congenital heart disease. For repair of CAVSD, the single-patch technique has been employed first. This technique requires division of the bridging leaflets, thus, among other issues, long-term function of the atrioventricular valves is of particular concern.

Methods  Between 1978 and 2001, 100 consecutive patients with isolated CAVSD underwent single-patch repair in our institution. Hospital mortality was 11%. Primary endpoints were clinical status, atrioventricular valve function, and freedom from reoperation in long term. Follow-up was obtained contacting the patient and/or caregiver, and the referring cardiologist.

Results  Eighty-three patients were eligible for long-term follow-up (21.0 ± 8.7, mean ± standard deviation [21.5; 2.1–40.0, median; min–max] years after surgical repair). Actual long-term mortality was 3.4%. Quality of life (QoL; self- or caregiver-reported in patients with Down syndrome) was excellent or good in 81%, mild congestive heart failure was present in 16%, moderate in 3.6% as estimated by New York Heart Association classification. Echocardiography revealed normal systolic left ventricular function in all cases. Regurgitation of the right atrioventricular valve was mild in 48%, mild–moderate in 3.6%, and moderate in 1.2%. The left atrioventricular valve was mildly stenotic in 15% and mild to moderately stenotic in 2%; regurgitation was mild in 54%, mild to moderate in 13%, and moderate in 15% of patients. Freedom from left atrioventricular-valve-related reoperation was 95.3, 92.7, and 89.3% after 5, 10, and 30 years, respectively. Permanent pacemaker therapy, as an immediate result of CAVSD repair ( n  = 7) or as a result of late-onset sick sinus syndrome ( n  = 5), required up to six reoperations in single patients. Freedom from pacemaker-related reoperation was 91.4, 84.4, and 51.5% after 5, 10, and 30 years, respectively.

Conclusion  Up to 40 years after single-patch repair of CAVSD, clinical status and functional results are promising, particularly, in terms of atrioventricular valve function. Permanent pacemaker therapy results in a life-long need for surgical reinterventions.

Complete atrioventricular septal defect with absent or diminutive primum component: Incidence, anatomic characteristics, and outcomes

BACKGROUND

Repair of complete atrioventricular septal defect with absent or diminutive primum defect is challenging because of atrial septal malposition and abnormal anatomy of the left atrioventricular valve. We sought to define the incidence, anatomy, and surgical outcomes of this entity.

METHODS

We identified all patients in our institutional database presenting for complete atrioventricular septal defect repair from 2006 to 2018. Operative reports and echocardiograms were reviewed to determine the presence and size of the primum defect, atrioventricular valve anatomy, degree of atrioventricular valve regurgitation, repair method, and complications, including reoperation for atrioventricular valve regurgitation. Functionally univentricular patients and those receiving repair at an outside institution were excluded.

RESULTS

Of 183 patients with complete atrioventricular septal defect, absent/diminutive primum defect occurred in 16 patients (8.7%; 10 absent, 6 diminutive). Six patients (38%) had leftward malposition of the atrium septum on the common atrioventricular valve. The rate of reoperation for left atrioventricular valve regurgitation was 31% (3 early, 2 late), for which preoperative predictors included leftward malposition of the atrial septum onto the common atrioventricular valve (4/6 patients with malposition required reoperation, P = .036, Fisher exact test). One patient exhibiting this risk factor died. The overall rate of moderate or greater left atrioventricular valve regurgitation on the most recent postoperative echocardiogram was 13% (2/16 patients; median follow-up, 141 days; range, 3-2236 days).

CONCLUSIONS

Complete atrioventricular septal defect with absent or diminutive primum defect is a unique variant of complete atrioventricular septal defect for which the risk of reoperation for left atrioventricular valve regurgitation after complete repair is high and risk factors include leftward malposition of the atrial septum on the common atrioventricular valve.

Double orifice and atrioventricular septal defect: dealing with the zone of apposition†

OBJECTIVES

A double orifice of the left atrioventricular valve (LAVV) associated with atrioventricular septal defects (AVSD) can significantly complicate surgical repair. This study reports our experience of AVSD repair over 3 decades, with special attention to the zone of apposition (ZoA) of the main orifice, and presents a technique of hemivalve pericardial extension in specific situations.

METHODS

We performed a retrospective study from 1987 to 2016 on 1067 patients with AVSD of whom 43 (4%) had a double orifice, plus 2 additional patients who required LAVV pericardial enlargement. Median age at repair was 1.3 years. Mean follow-up was 8.2 years (1 month-32 years).

RESULTS

Associated abnormalities of the LAVV subvalvular apparatus were found in 7 patients (5 parachute LAVV and 2 absence of LAVV subvalvular apparatus). ZoA was noted in 4 patients (9%): partially closed in 15 (35%) and completely closed in 24 (56%). Four patients required, either at first repair or secondarily, a hemivalve enlargement using a pericardial patch without closure of the ZoA. The early mortality rate was 7% (n = 3), all before 2000. Two patients had unbalanced ventricles and the third had a single papillary muscle. There were no late deaths. Six patients (14%) required 7 reoperations (3 early and 4 late reoperations) for LAVV regurgitation and/or dysfunction, of whom 4 (9%) required mechanical LAVV replacement (all before 2000). Freedom from late LAVV reoperation was 97% at 1 year, 94% at 5 years and 87% at 10, 20 and 30 years. Unbalanced ventricles (P = 0.045), subvalvular abnormalities (P = 0.0037) and grade >2 LAVV postoperative regurgitation (P = 0.017) were identified as risk factors for LAVV reoperations. Freedom from LAVV mechanical valve replacement was 95% at 1 year, 90% at 5 years and 85% at 10, 20 and 30 years. An anomalous LAVV subvalvular apparatus was identified as a risk factor for mechanical valve replacement (P = 0.010). None of the patients who underwent LAVV pericardial extension had significant LAVV regurgitation at the last follow-up examination.

CONCLUSIONS

Repair of AVSD and double orifice can be tricky. Preoperative LAVV regurgitation was not identified as an independent predictor of surgical outcome. LAVV hemivalve extension appears to be a useful and effective alternate surgical strategy when the ZoA cannot be closed.

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.

Dysrhythmias in patients with a complete atrioventricular septal defect: From surgery to early adulthood

Objective

Outcomes after surgical repair of complete atrioventricular septal defect (cAVSD) have improved. With advancing age, the risk of development of dysrhythmias may increase. The aims of this study were to (1) examine development of sinus node dysfunction (SND), atrial and ventricular tachyarrhythmias, and (2) study progression of atrioventricular conduction abnormalities in young adult patients with repaired cAVSD.

Study design

In this retrospective multicenter study, 74 patients (68% female) with a cAVSD repaired in childhood were included. Patients’ medical files were evaluated for occurrence of SND, atrioventricular conduction block (AVB), atrial and ventricular tachyarrhythmias.

Results

Median age at repair was 6 months (interquartile range 3‐10) and median age at last follow‐up was 24 years (interquartile range 21‐28). SND occurred after a median of 17 years (interquartile range 11‐19) after repair in 23% of patients, requiring pacemaker implantation in two patients (12%). Regular supraventricular tachycardia was observed in three patients (4%). Atrial fibrillation and ventricular tachyarrhythmias were not observed. Twenty‐seven patients (36%) had first‐degree AVB, which was self‐limiting in 16 (59%) and persistent in 10 (37%) patients. One patient developed third‐degree AVB 7 days after left atrioventricular valve replacement. Spontaneous type II second‐degree AVB occurred in a 28‐year‐old patient. Both patients underwent pacemaker implantation.

Conclusions

Clinically significant dysrhythmias were uncommon in young adult patients after cAVSD repair. However, three patients required pacemaker implantation for either progression of SND or spontaneous type II second‐degree AVB. Longer follow‐up should point out whether dysrhythmias will progress or become more prevalent with increasing age.

Outcomes and Prognostic Factors for Adult Patients With Congenital Heart Disease Undergoing Primary or Reoperative Systemic Atrioventricular Valve Surgery

BACKGROUND

Adults with congenital heart disease (ACHD) undergoing systemic atrioventricular valve (SAVV) surgery are a complex, understudied population. We assessed midterm outcomes and prognostic factors in ACHD undergoing SAVV surgery.

METHODS

We performed retrospective evaluation of ACHD undergoing SAVV surgery from January 2005 to February 2016: 14 (33%) patients with congenital mitral valve stenosis/regurgitation, 15 (35%) with atrioventricular septal defect (AVSD), and 14 (33%) with congenitally corrected transposition of the great arteries (ccTGA) with systemic tricuspid valve regurgitation. Adverse events were defined as mortality, reoperation on SAVV, and late more-than-moderate (> moderate) SAVV regurgitation. Statistical analysis was performed using Fisher's exact test and one-way analysis of variance as well as univariate and multivariate risk factor analysis.

RESULTS

Fifteen (35%) patients had preoperative systemic ventricular dysfunction, including 13 patients with ccTGA (93%, P < .001). Twenty-three (54%) patients underwent valve repair, 20 (47%) patients underwent replacement, and 20 (47%) patients underwent an associated procedure. Replacement was higher in patients with ccTGA (86%) than the other groups ( P < 0.01). Thirty-seven patients (91% of survivors) were free of significant SAVV regurgitation at last follow-up, with patients with AVSD having greater regurgitation grades compared to the other groups ( P < 0.01). In-hospital mortality, late mortality, late > moderate SAVV regurgitation, and SAVV reoperation rates were 5% (n = 2), 2% (n = 1), 9% (n = 3), and 7% (n = 3), respectively. On multivariate analysis, predischarge SAVV regurgitation grade was the only significant predictor of adverse events (odds ratio = 8.2, 95% confidence interval: 1.1-63.8, P = .045).

CONCLUSION

Overall outcomes in this challenging population are good. The single factor associated with adverse events was predischarge SAVV regurgitation grade.

The angulation of the septal structures impacts ventricular imbalance in atrioventricular septal defects with a common atrioventricular junction

OBJECTIVE

Multiplanar re-formatting of full-volume three-dimensional echocardiography data sets offers new insights into the morphology of atrioventricular septal defects. We hypothesised that distortion of the alignment between the atrial and ventricular septums results in imbalanced venous return to the ventricles, with consequent proportional ventricular hypoplasia.

METHODS

A single observer evaluated 31 patients, with a mean age of 52.09 months, standard deviation of 55, and with a range from 2 to 264 months, with atrioventricular septal defects, of whom 17 were boys. Ventricular imbalance, observed in nine patients, was determined by two-dimensional assessment, and confirmed at surgical inspection in selected cases when a univentricular strategy was undertaken. Offline analysis using multiplanar re-formatting was performed. A line was drawn though the length of the ventricular septum and a second line along the plane of the atrial septum, taking the angle between these two lines as the atrioventricular septal angle. We compared the angle between 22 patients with adequately sized ventricles, and those with ventricular imbalance undergoing univentricular repair.

RESULTS

In the 22 patients undergoing biventricular repair, the septal angle was 0 in 14 patients; the other eight patients having angles ranging from 1 to 36, with a mean angle of 7.4°, and standard deviation of 11.1°.The mean angle in the nine patients with ventricle imbalance was 28.6°, with a standard deviation of 3.04°, and with a range from 26 to 35°. Of those undergoing univentricular repair, two patients died, with angles of 26 and 30°, respectively.

CONCLUSIONS

The atrioventricular septal angle derived via multiplanar formatting gives important information regarding the degree of ventricular hypoplasia and imbalance. When this angle is above 25°, patients are likely to have ventricular imbalance requiring univentricular repair.

Partial and intermediate atrioventricular septal defects without major associated cardiac anomalies

Partial and intermediate atrioventricular septal defects (p-i AVSDs) constitute approximately 20-40% of all AVSDs. Children with p-i AVSDs are usually asymptomatic and typically undergo surgery at the preschool age or earlier if the signs of heart failure have developed. Surgical treatment for repair of p-i AVSDs has been successful for more than 60 years and is mainly directed towards closing septal defects, and maintaining or creating competent, non-stenotic left and/or right atrioventricular valves. By most measures, the outcomes of surgical management of p-i AVSDs have improved over the last 5 decades. In spite of significantly reduced mortality, the need for reoperation and long-term morbidity remains an issue in some patients from this population. The purpose of this article is to review current options and outcomes concerning the surgical management of the p-AVSD and i-AVSD variants without major associated cardiac malformations.

Three-dimensional echocardiography for the assessment of atrioventricular valves in congenital heart disease: past, present and future

Echocardiography has developed as an imaging technology over 60 years to become the mainstay for investigating heart disease, providing invaluable structural and functional information. In the last 20 years, 3-dimensional echocardiography (3DE) has emerged as an adjunct to 2-dimensional echocardiography in adult and congenital heart disease. Early work with 3-dimensional imaging of the mitral valve describing normal annular shape and function significantly changed the understanding of mitral valve dynamics. Further work led to our current understanding of the mitral valve working as a unit, with all components vital to its normal function. With improving technology and ease of use, similar 3DE techniques have been used in congenital heart disease to study the unique anatomy and function of atrioventricular (AV) valves, specifically the tricuspid valve in hypoplastic left heart syndrome, and the left AV valve in atrioventricular septal defects. This paper describes the role of 3DE in assessing AV valve function in normal valves, and in congenital heart disease.

Should repair of partial atrioventricular septal defect be delayed until later in childhood?

Surgical repair of partial atrioventricular septal defects (AVSD) has been successful for more than 60 years. However, recent data from the Pediatric Heart Network show that 31% of patients have moderate or severe left atrioventricular valve regurgitation (LAVVR) at follow-up. Previously, our institution found that only 9% of patients had more than moderate LAVVR at the last follow-up. Our objective was to determine the long-term outcomes after repair of partial AVSD in the current era. We reviewed all patients with partial AVSD who had primary biventricular repair from January 1995 to June 2011 at our institution. The Kaplan-Meier method was used to estimate the survival free of an event, and factors were evaluated for an association with each outcome using the log-rank test. All 105 patients with partial AVSD who had surgery during this period were evaluated. The median age at surgery was 7.9 years. The overall survival rate at 1 year was 97%. Median follow-up was 5.3 years (interquartile range 1.7 to 11.1). At 3 years, the survival rate free from reoperation was 89%. Thirteen patients required reoperations with the most common reason being LAVVR. A total of 10 patients developed more than moderate LAVVR with a cumulative incidence of 8% by 2 years. The discrepancy with the Pediatric Heart Network data may be due to the later age of operation for patients in our cohort suggesting that elective repair of partial AVSD should be deferred until children are somewhat older (ages 5 to 8 years). Neither patient age (p = 0.11) nor severity of preoperative LAVVR (p = 0.16) were identified as statistically significant risk factors. In conclusion, there is less morbidity and mortality after surgical repair for partial AVSD.

Outcomes of repair of complete atrioventricular septal defect in the current era

OBJECTIVES

We sought to evaluate the surgical outcomes of the repair of complete atrioventricular septal defects (cAVSDs) in our institution in the current era.

METHODS

From 2000 to 2011, 138 patients underwent definitive repair of cAVSD. Repair was performed using a two-patch technique in 92.0% of patients and one-patch technique in 2.2%, and the ventricular septal component was closed directly in 5.8% of patients.

RESULTS

Operative mortality was 1.4% (2 of 138). Overall mortality was 5.8% (8 of 138). Follow-up was 96% complete. Freedom from reoperation was 84.3% (95% CI 77.1-91.5%) at 8 years. Age >6 months at repair was associated with higher rates of reoperation (P = 0.001; HR 6.85; 95% CI 2.30-20.44). However, operating at <6 months of age was associated with longer intensive care unit stay (P = 0.019; median 2.7 vs 1.4 days), mechanical ventilation (P = 0.001; median 1.7 vs 0.9 days) and postoperative hospital stay (P = 0.016; median 8 vs 5 days). Moderate or greater left atrioventricular valvular regurgitation (LAVVR) at discharge was a risk factor for reoperation (P < 0.001; HR 10.85; 95% CI 3.75-31.40).

CONCLUSIONS

Repair of cAVSD carries low mortality, but a moderate reoperation rate. An optimal time for repair of the cAVSD is between 3 and 6 months of age. Repair prior to 3 months of age and the need for cleft closure were associated with a higher degree of LAVVR at discharge. Greater LAVVR at discharge is a risk factor for reoperation regardless of age at initial repair. In the current era, Down's syndrome is not a risk factor for reoperation.

Reoperations for left atrioventricular valve dysfunction after repair of atrioventricular septal defect

OBJECTIVES

Postoperative left atrioventricular valve (LAVV) dysfunction is known to be the principal risk factor influencing outcome after repair of all types of atrioventricular septal defect (AVSD). The purpose of the present study was to identify the risk factors for reoperation and to assess the outcomes after reoperation for LAVV dysfunction.

METHODS

Records of 412 patients who underwent anatomical repair for different types of AVSD from January 2000 to July 2012 were reviewed. The study group (n = 60) included 13 additional patients for whom repair ± LAVV reoperation was performed in a primary institution. Outcomes, independent risk factors, reoperation and death were analysed.

RESULTS

There were 7 early, (1.7%) and 1 late death. Forty-seven (11.4%) required 64 reoperations for LAVV dysfunction. The median delay for the first LAVV reoperation was 3.5 months (range: 5 days to 10.0 years). Unbalanced ventricles with small left ventricle [odds ratio (OR) = 4.06, 95% confidence interval (CI): 1.58-10.44, P = 0.004], double-orifice LAVV (OR = 5.04, 95% CI: 1.39-18.27, P = 0.014), prior palliative surgery (OR = 3.5, 95% CI: 1.14-10.8, P = 0.029) and discharge echocardiography documenting LAVV regurgitation grade >2 (OR = 21.96, 95% CI: 8.91-54.09, P < 0.001) were found to be independent risk factors for LAVV reoperation. Twelve-year survival and freedom from LAVV reoperation rates were, respectively, 96.1% (95% CI: 94.1-98.1) and 85.8% (95% CI: 81.3-90.3). Survival was significantly worse in patients who underwent LAVV reoperation (P < 0.001) and in those who underwent valve replacement vs valve repair (P = 0.020).

CONCLUSION

After AVSD repair, LAVV dysfunction appears to be the principal factor that influences outcome. It can usually be managed by repair. Need for multiple reoperations is not uncommon. Long-term outcome in patients with repaired LAVV is favourable.

Challenges in echocardiographic assessment of mitral regurgitation in children after repair of atrioventricular septal defect

The validity and reproducibility of echocardiographic methods used to quantify mitral regurgitation (MR) in children with congenital heart disease are unknown. We evaluated the usefulness of methods used to quantify MR in children enrolled in a multicenter trial of enalapril 6 months after surgical repair of an atrioventricular septal defect (AVSD). MR severity in this trial was assessed using body surface area (BSA)-adjusted vena contracta lateral (i-VCW(lat)) and anterior-posterior (i-VCW(ap)) dimensions and cross-sectional area (i-VCA), regurgitant volume/BSA, regurgitant fraction, and qualitative MR grade. For each method, association with left ventricular end-diastolic volume (LVEDVz) and end-diastolic dimension (LVEDDz) z-scores and interobserver agreement were assessed. In 149 children (median age 1 year), i-VCW(lat), i-VCW(ap), and i-VCA were best associated with LVEDVz (r (2) = 0.54, r (2) = 0.24, and r (2) = 0.46, respectively; p < 0.001 for all) and showed the highest interobserver agreement (intraclass correlation coefficient = 0.62, 0.73, and 0.68, respectively). Qualitative MR grade was also associated with LVEDVz (r (2) = 0.31, p < 0.001) and showed modest interobserver agreement (kappa 0.56). Regurgitant volume/BSA and regurgitant fraction were associated with LVEDVz (r (2) = 0.45 and r (2) = 0.45, p < 0.001 for both) but showed poor interobserver agreement [ICC = 0.28 (n = 91) and ICC = 0.17 (n = 76), respectively], and their values were negative in 75% of subjects. In conclusion, echocardiographic assessment of MR severity after AVSD remains challenging. Among the quantitative methods used in this trial, i-VCW and i-VCA performed the best but offered little advantage compared with qualitative MR grade. The utility of regurgitant volume and fraction was severely limited by poor interobserver agreement and frequently negative values.

Long-term results of reoperation for left atrioventricular valve regurgitation after correction of atrioventricular septal defects

BACKGROUND

Long-term results of reoperation for left atrioventricular valve regurgitation (LAVVR) after previous correction of atrioventricular septal defect (AVSD) are scarce. We evaluated long-term outcome of reoperation for LAVVR and identified risk factors for reoperation.

METHODS

Between December 1976 and July 2006, 45 of 312 patients with correction of different AVSDs underwent reoperation for LAVVR. The cohort of 267 patients who did not need reoperation for LAVVR allowed for the identification of risk factors for reoperation and evaluation of overall survival after primary AVSD repair in a competing risk scenario. Clinical data were obtained by retrospective review.

RESULTS

The left atrioventricular valve (LAVV) was repaired in 31 patients (68.9%) and replaced in 14 (31.1%). There were 3 in-hospital deaths (6.7%) and 2 late deaths (4.4%). Estimated overall survival was 88.1% at 15 years after the reoperation, and estimated incidence of death after reoperation in the total patient cohort was 2% at 15 years after the primary AVSD repair. Overall survival was significantly higher after LAVV repair than after replacement (p=0.010). Ten patients with LAVV repair required a second reoperation for LAVVR. At follow-up, survivors were in New York Heart Association functional class I (n=36) or II (n=4). Independent risk factors for first reoperation for LAVVR were associated cardiovascular anomalies (p<0.001), LAVV dysplasia (p<0.001), and nonclosure of the cleft (p=0.027).

CONCLUSIONS

After previous correction of AVSD, LAVVR can usually be corrected by valve repair. A very dysplastic valve may necessitate replacement. Overall survival is higher after repair than after replacement. In general, overall survival of patients reoperated on for LAVVR is favorable. The overall mortality rate after primary repair of AVSD is explained only for a small part by mortality after reoperation for LAVVR.

Early outcomes and prognostic factors for left atrioventricular valve reoperation after primary atrioventricular septal defect repair

This study aimed to identify early outcomes of and prognostic factors for left atrioventricular valve (LAVV) reoperation after primary atrioventricular septal defect (AVSD) repair. A retrospective cohort study was performed using the Pediatric Cardiac Care Consortium database, which included 370 patients with previously repaired AVSDs who subsequently underwent LAVV reoperation between 1982 and 2007. Of these patients, 243 underwent LAVV repair, and 127 underwent LAVV replacement. Median time to first reoperation after primary repair was 0.67 years in the repair subgroup and 0.18 years in the replacement subgroup. Thirty-day survival was significantly poorer in the replacement subgroup compared with the repair subgroup (P = 0.0002). In multivariable analysis, independent predictors of earlier time to valve replacement included presence of Down syndrome and postoperative left atrioventricular valve stenosis. Independent predictors of in-hospital death after valve replacement included presence of Down syndrome (hazard ratio [HR] 2.34, 95% CI 1.19-4.58) and prosthetic valve size-to-weight ratio >3 mm/kg (HR 3.02, 95% CI 1.52-6.01). The identification of a subgroup of previously repaired AVSD patients at high risk for early postoperative death after LAVV replacement suggests that for these patients, a low threshold for detailed hemodynamic monitoring and/or reintervention for hemodynamic aberrations is warranted.

Lessons learned from a pediatric clinical trial: the Pediatric Heart Network angiotensin-converting enzyme inhibition in mitral regurgitation study

BACKGROUND

Mitral regurgitation is the most common indication for reoperation in children following repair of atrioventricular septal defect (AVSD). We hypothesized that angiotensin-converting enzyme inhibitor therapy would decrease the severity of mitral regurgitation and limit left ventricular volume overload in children following AVSD repair.

METHODS

The Pediatric Heart Network designed a placebo-controlled randomized trial of enalapril in this population. The primary aim was to test the effect of enalapril on the change in left ventricular end-diastolic dimension body surface area-adjusted z score. Before the launch of the trial, a feasibility study was performed to estimate the number of patients with at least moderate mitral regurgitation following AVSD repair.

TRIAL EXPERIENCE

Seventeen months after the start of the study, 349 patients were screened, 8 were trial eligible, and only 5 were enrolled. The study was subsequently terminated because of low patient accrual. Several factors led to the problems with patient accrual, including (1) the use of criteria to assess disease severity in the feasibility study that were not identical to those used in the trial, (2) failure to achieve equipoise for the study among clinicians and referring physicians, (3) reliance on methodology developed in adult populations with different disease mechanisms, and (4) absence of adequate data to define the natural history of the disease process under study. Progress in the treatment of children with cardiovascular disease will depend on the future of multicenter collaborative clinical trials. The lessons learned from this study may contribute to improvements in this research.

Reoperations After Repair of Partial and Complete Atrioventricular Septal Defect

The most common cause of reoperation following repair of atrioventricular septal defect (AVSD) is left atrioventricular valve regurgitation. However, reoperation for subaortic obstruction is required in some, especially after initial repair of partial AVSD. Etiology of reoperation and late outcome were evaluated. Between 1962 and 2007, 146 patients (59 male) underwent reoperation at the authors' institution after prior repair of partial (n = 96) and complete (n = 50) AVSD. Median age at reoperation after repair of partial AVSD was 26 years (range, 10 months to 71 years) and 4.5 years (range, 53 days to 38 years) after repair of complete AVSD. The 3 most common indications for reoperation included left atrioventricular (AV) valve regurgitation in 105 patients, subaortic stenosis in 29, and right AV valve regurgitation in 21. The most common procedures performed included left AV valve repair in 59 (40%) patients, left AV valve replacement in 56 (38%), subaortic fibrous resection/myectomy in 24 (16%), and right AV valve surgery in 19 (13%). Freedom from subsequent reoperation at 10 years was 48% after initial repair of complete AVSD and 84% after initial repair of partial AVSD. During late follow-up, 10-year actuarial survival was 91% and 77% after initial repair of complete and partial AVSD, respectively. The most common indication for reoperation after initial repair of partial or complete AVSD is left AV valve pathology; left ventricular outflow tract obstruction was more common in partial AVSD. Although freedom from subsequent reoperations is higher after initial repair of partial AVSD, these patients have reduced long-term survival when compared with complete AVSD.

Partial and transitional atrioventricular septal defect outcomes

BACKGROUND

Surgical and perioperative improvements permit earlier repair of partial and transitional atrioventricular septal defects (AVSD). We sought to describe contemporary outcomes in a multicenter cohort.

METHODS

We studied 87 patients undergoing primary biventricular repair of partial or transitional AVSD between June 2004 and February 2006 across seven North American centers. One-month and 6-month postoperative data included weight-for-age z-scores, left atrioventricular valve regurgitation (LAVVR) grade, residual shunts, and left ventricular ejection fraction. Paired methods were used to assess 6-month change.

RESULTS

Median age at surgery was 1.8 years; median weight z-score was -0.88. Median days for ventilation were 1, intensive care 2, and hospitalization 5, all independent of age, with 1 in-hospital death. At 1 month, 27% (16 of 73) had ejection fraction less than 55%; 20% (17 of 87) had significant LAVVR; 2 had residual shunts; 1 each had subaortic stenosis and LAVV stenosis. At 6 months (n = 60), there were no interim deaths, reinterventions, or new development of subaortic or LAVV stenosis. Weight z-score improved by a median 0.4 units (p < 0.001), especially for underweight children less than 18 months old. Left atrioventricular valve regurgitation occurred in 31% (change from baseline, p = 0.13), occurring more frequently in patients repaired at 4 to 7 years (p = 0.01). Three patients had ejection fraction less than 55%, and 1 had a residual atrial shunt.

CONCLUSIONS

Surgical repair for partial/transitional AVSD is associated with low morbidity and mortality, short hospital stays, and catch-up growth, particularly in underweight children repaired between 3 and 18 months of age. Left atrioventricular valve regurgitation remains the most common residual defect, occurring more frequently in children repaired after 4 years of age.

Cleft closure and undersizing annuloplasty improve mitral repair in atrioventricular canal defects

OBJECTIVE

Reoperation rates to correct left atrioventricular valve regurgitation after primary repair of atrioventricular canal defects remain relatively high. The causes of valvular regurgitation are likely multifactorial, and simple cleft closure is often insufficient to prevent recurrence.

METHODS

To elucidate the mechanisms leading to regurgitation, we conducted hemodynamic studies using isolated native mitral valves. Anatomy of these valves was altered to mimic atrioventricular canal type valves and studied under pediatric hemodynamic conditions. The impact of subvalvular geometry, cleft closure, annular dilatation, and annular undersizing on regurgitation were investigated.

RESULTS

Papillary muscle position did not have a significant effect on regurgitation. Cleft closure had a significant impact on valvular competence, with reduction in regurgitation volume with increased cleft closure. Regurgitation volume decreased from 12.5 +/- 2.4 mL/beat for an open cleft to 4.9 +/- 1.9 mL/beat for a partially closed cleft and to 1.4 +/- 1.6 mL/beat when the cleft was completely closed. Annular dilatation had a significant impact on regurgitation even after cleft closure. A 40% increase in annular size increased regurgitation by 59% for a partially closed cleft and by 84% for a fully closed cleft. Reducing the annular size by 20% from the physiologic level decreased the regurgitation volume by 12% for a fully open cleft and by 58% for the partially closed cleft case.

CONCLUSIONS

Annular dilatation after primary repair has a potentially significant role in the recurrence of atrioventricular valve regurgitation. Reducing the annular size and restricting dilatation as an adjunct to cleft closure is a promising surgical approach in such valve anatomies.

Atrioventricular canal: single-patch technique

Complete atrioventricular septal defects have been repaired at the Medical University of South Carolina for the past 25 years using the "single-patch technique" as first described by the Mayo Clinic group in 1968. In this technique, the single atrioventricular valve is separated into left (mitral) and right (tricuspid) components by dividing the superior and inferior bridging leaflets back to the annulus. A single patch of bovine pericardium is sutured to the right ventricular aspect of the ventricular septum, the previously divided valve leaflets are resuspended to the patch, the "cleft" in the left-sided valve is closed with interrupted sutures, and the atrial component of the defect closed by suturing the patch to the atrial septum with a continuous suture. Since 1995, there have been no operative deaths in the 88 consecutive infants undergoing this repair in our institution. Nine patients (10.2%) have required reoperation for severe mitral regurgitation. While the issue of operative mortality in patients undergoing single-patch repair of complete atrioventricular septal defect has largely been eliminated, residual or recurrent mitral regurgitation continues to be a problem.

Complex atrioventricular canal

Complex forms of atrioventricular (AV) canal (C) such as; AVC with left ventricular outflow tract obstruction, tetralogy of Fallot with complete AVC, double orifice left AV valve, unbalanced complete AVC, and single ventricle patients with common AVC valve require careful preoperative planning and special techniques. This review will explore these technical modifications and outcomes for repair of complex variants of AVC. Optimal results will be achieved using an individually tailored approach that is guided by careful evaluation of the preoperative studies, precise operative technique, and intraoperative assessment of the reconstructed AV valve, as well as a willingness to re-intervene should the postoperative course not proceed as anticipated.

Three-dimensional Echocardiography Improves the Understanding of the Mechanisms and Site of Left Atrioventricular Valve Regurgitation in Atrioventricular Septal Defect

OBJECTIVES

The purpose of this study was to determine whether 3-dimensional echocardiography (3DE) provides additional information regarding the mechanisms and sites of left atrioventricular valve regurgitation in atrioventricular septal defect compared with transesophageal 2-dimensional echocardiography (2DE).

METHODS

Eleven patients with a median age of 5.4 years (2.9-11.6 years) and a median weight of 16.8 kg (13.7-38.3 kg) with an atrioventricular septal defect underwent simultaneous transesophageal 2DE and 3DE before operation.

RESULTS

The 2DE-3DE agreement for the assessment of the superior and mural leaflet size was 72.7%. The 2DE-3DE agreement for coaptation failure, a residual or primary cleft, and commissural abnormalities as a mechanism of regurgitation were 72.7%, 63.6%, and 36.4%, respectively. For jet sites the 2DE-3DE agreement was 63.6% for a commissural and central location.

CONCLUSION

Three-dimensional echocardiography provides new and superior data regarding the mechanisms and sites of left atrioventricular valve regurgitation in atrioventricular septal defect.