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

Published:August 12, 2022DOI:https://doi.org/10.1016/j.jtcvs.2022.07.041

      Abstract

      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.

      Graphical abstract

      Figure thumbnail fx1

      Key Words

      Abbreviations and Acronyms:

      CAVSD (complete atrioventricular septal defects), CI (confidence interval), ICR (intracardiac repair), IQR (interquartile range), LAVV (left atrioventricular valve), LAVVR (left atrioventricular valve regurgitation), LVOT (left ventricular outflow tract), LVOTO (left ventricular outflow tract obstruction), MSP (modified single-patch repair), PAB (pulmonary artery banding), ROC (receiver operating characteristic), TP (2-patch repair), VSD (ventricular septal defect)
      Figure thumbnail fx2
      The MSP-deep VSD group exclusively showed worse LAVV competence (95% CI).
      Moderate or greater left atrioventricular valve regurgitation after modified single-patch repair for patients with complete AVSD is comparable with 2-patch repair unless deep VSD is present.
      One surgical technique might not always be superior because each technique is best suited to specific anatomical configurations. Applying the right technique to the right anatomy will result in the best functional outcomes. The incidence of postoperative left atrioventricular valve regurgitation can still be reduced. Our findings provide guidance in choosing the optimal repair approach in such cases.
      See Commentary on page 422.
      Excellent short- and long-term survival rates are usually achieved after surgical repair of balanced complete atrioventricular septal defects (CAVSD). Therefore, attention has shifted from mortality to functional outcomes or residual lesions that influence patients’ quality of life. The most notable and troublesome postoperative complication is progressive left atrioventricular valve (LAVV) regurgitation (LAVVR), which sometimes requires surgical reintervention followed by thorough medical intervention. Its incidence ranges from 7% to 14%.
      • Fong L.S.
      • Betts K.
      • Bell D.
      • Konstantinov I.E.
      • Nicholson I.A.
      • Winlaw D.S.
      • et al.
      Complete atrioventricular septal defect repair in Australia: results over 25 years.
      • Buratto E.
      • Lui A.
      • Hu T.
      • Naimo P.
      • Ivanov Y.
      • d’Udekem Y.
      • et al.
      Propensity score matched analysis of cleft closure in complete atrioventricular septal defect repair.
      • Bell D.
      • Thakeria P.
      • Betts K.
      • Justo R.
      • Jalali H.
      • Wijesekera V.
      • et al.
      Propensity-matched comparison of the long-term outcome of the Nunn and two-patch techniques for the repair of complete atrioventricular septal defects.
      • Airaksinen R.
      • Mattila I.
      • Jokinen E.
      • Salminen J.
      • Puntila J.
      • Lehtinen M.L.
      • et al.
      Complete atrioventricular septal defect: evolution of results in a single center during 50 years.
      • Mery C.M.
      • Zea-Vera R.
      • Chacon-Portillo M.A.
      • Zhu H.
      • Kyle W.B.
      • Adachi I.
      • et al.
      Contemporary outcomes after repair of isolated and complex complete atrioventricular septal defect.
      The evolution of surgical techniques includes the modified single-patch repair (MSP) first advocated by Wilcox and colleagues
      • Wilcox B.R.
      • Jones D.R.
      • Frantz E.G.
      • Brink L.W.
      • Henry G.W.
      • Mill M.R.
      • et al.
      Anatomically sound, simplified approach to repair of “complete” atrioventricular septal defect.
      in 1997 and encouraged by Nicholson and colleagues
      • Nicholson I.A.
      • Nunn G.R.
      • Sholler G.F.
      • Hawker R.E.
      • Cooper S.G.
      • Lau K.C.
      • et al.
      Simplified single patch technique for the repair of atrioventricular septal defect.
      in 1999. Earlier intracardiac repair (ICR) has been facilitated by a distinctive procedure characterized as the “no ventricular septal defect (VSD) patch” technique.
      • Backer C.L.
      • Stewart R.D.
      • Bailliard F.
      • Kelle A.M.
      • Webb C.L.
      • Mavroudis C.
      Complete atrioventricular canal: comparison of modified single-patch technique with two-patch technique.
      This omission of the VSD patch closure, which is the most complicated part of 2-patch repair (TP), especially for young infants, removes a potential error related to the VSD patch size and simplifies the entire procedure, contributing to shorter cardiopulmonary bypass and aortic crossclamp times. However, this feature simultaneously raises a critical issue, because the atrioventricular valve is pulled down to the ventricular septal crest and might impair valve competence in the setting of a deep VSD.
      Several reports have compared MSP with TP, including a recently published systematic review. However, no large study has investigated whether VSD depth affects the choice of surgical techniques from the perspective of long-term LAVV competence. Therefore, we compared the effect of MSP and TP on LAVV competence, stratified according to VSD depth, over a 20-year period and identified morphological risk factors for moderate or greater postoperative LAVVR.

      Methods

      Patients

      This retrospective, nonrandomized, single-institution study included 118 patients with balanced CAVSD who underwent ICR at Okayama University Hospital between June 1998 and September 2020; 69 patients underwent MSP whereas 49 underwent TP. Patients with an associated diagnosis of tetralogy of Fallot or single papillary muscle were excluded. Our hospital's institutional review board approved this study, and the requirement for written informed consent was waived because of its observational nature (approval number 2009-023; approval date: October 23, 2020). A thorough retrospective review of the medical records was conducted. Preoperative, intraoperative, postoperative (before discharge), and follow-up data were collected from clinical reports.

      Follow-up

      Follow-up was completed in January 2021 with a median of 10.4 years (interquartile range [IQR], 4.9-14.4 years), which differed according to surgical approach, with a median of 7.1 (IQR, 3.0-10.9) years in the MSP group and 14.8 (IQR, 10.5-18.6) years in the TP group. A total of 113 of 116 (97%) hospital survivors underwent complete follow-up, including echocardiography by a cardiologist in our hospital within a year of the end of the study period.

      Study End Points and Measurements

      The primary end points were survival, reoperation related to LAVVR, and moderate or greater postoperative LAVVR measured using echocardiography. All recordings of 2-dimensional, M-mode, and Doppler images were repeatedly obtained by a few cardiologists specializing in echocardiography in conformance with the recommendations of the American Society of Echocardiography guidelines, and Z scores were generated.
      • Lopez L.
      • Colan S.D.
      • Frommelt P.C.
      • Ensing G.J.
      • Kendall K.
      • Younoszai A.K.
      • et al.
      Recommendations for quantification methods during the performance of a pediatric echocardiogram: a report from the Pediatric Measurements Writing Group of the American Society of Echocardiography Pediatric and Congenital Heart Disease Council.
      Left ventricular end-diastolic diameter was measured during diastole in the parasternal short-axis view. The VSD depth was defined as the distance between the ventricular crest and the closed atrioventricular valvular leaflets during diastole in the 4-chamber view. The VSD depth index was calculated and divided by the body surface area.
      Mechanical ventilatory support was defined as a preoperative need for intubation. LAVV anomaly was defined as the presence of a double orifice LAVV, significant deficient lateral leaflet, or dysplastic leaflet.
      • Lange R.
      • Guenther T.
      • Busch R.
      • Hess J.
      • Schreiber C.
      The presence of Down syndrome is not a risk factor in complete atrioventricular septal defect repair.

      Operative Technique

      Criteria for primary ICR included body weight >4 kg, no association with other cardiac anomalies, and no preoperative shock or other organ dysfunction; otherwise, pulmonary artery banding (PAB) was performed as the first palliation in symptomatic neonates or early infants who had large VSD leading to secondary LAVVR and congestive heart failure. These palliated patients were enrolled on the waiting list when their body weight exceeded 4 kg. All ICRs were performed via a median sternotomy with aortobicaval cannulation and moderate hypothermia. TP was performed exclusively by 1 surgeon (S.S.) until MSP was first introduced at our institution in 2002; thereafter, both techniques have been performed by 2 surgeons (S.S. and S.K.). The decision regarding the surgical technique was made by the professor of cardiovascular surgery in a multidisciplinary meeting, which included cardiologists, and was mostly determined by the presence of outlet extension VSD rather than VSD depth. The decision made was not reversed during the operation. MSP (Video 1) involved direct closure of the VSD component using multiple interrupted mattress sutures placed on the right side of the interventricular crest, passed through the bridging leaflets, whose division line had a slight shift to the right side, through the autologous pericardial patch that was to close the atrial septal defect, and through a thin felt strip. After these sutures were tied, the zone of apposition between the superior and inferior bridging leaflets in the LAVV was approximated with multiple interrupted simple sutures up to the point where the chordae inserted on the valve leaflet, unless this would have led to LAVV stenosis. The remainder of the pericardial patch was used to close the primum atrial septal defect while the coronary sinus was kept draining into the right atrium. The apposition zone in the right atrioventricular valve was also closed with 1 or 2 interrupted simple sutures. In TP, the VSD component was closed with a Dacron (DuPont de Nemours Inc) patch. Then a series of sutures were passed through the free edge of the patch, superior and inferior bridging leaflets, and the autologous pericardial patch and finally tied down. The remaining procedures were the same as for MSP.

      Statistical Analysis

      Continuous variables are reported as median (IQR) for skewed data or mean (standard deviation) for values with normal distribution. Categorical variables are reported as absolute frequency (percentage). Continuous variables were compared using the t test or Mann–Whitney U test on the basis of the normality of the data. Categorical variables were compared using Pearson χ2 test. In cases in which the expected frequency was <5, Fisher’ exact test was used. Receiver operating characteristic (ROC) curves were calculated to determine the best cutoff value of VSD depth for moderate or greater postoperative LAVVR. Accuracy was measured according to the area under the ROC curve. A multivariate Cox proportional hazards regression model was used to determine the independent risk factors of moderate or greater postoperative LAVVR, with a backward elimination strategy, beginning with a baseline model including all variables in univariate analysis with a value of P <.05. Variables were subsequently removed one by one according to P value (highest to lowest), to only include risk factors with a value of P <.05 in the final model. The hazard ratios and 95% confidence intervals (CIs) are reported for multivariate risk factors with a value of P <.05. Estimates of survival, freedom from reoperation, and moderate or greater LAVVR were made using the Kaplan–Meier method. Censoring was performed at the time of the last follow-up or death. All statistical analyses were performed with SPSS version 28 (IBM Corp) and GraphPad Prism software version 9 (GraphPad Software Inc).

      Results

      Demographic Characteristics

      Median age and weight at ICR were 176 (IQR, 123-330) days and 5.3 (IQR, 4.2-6.5) kg, respectively. Twenty-one (18%) patients weighed <4.0 kg. Thirty-nine (33%) patients underwent initial PAB for palliation. The characteristics of the patients who underwent MSP and TP were compared (Table 1). Age and weight at ICR were not different between the 2 groups. Trisomy 21 and Rastelli type C anatomy were more common in the TP group. Preoperative echocardiography before ICR showed that VSD depth in the MSP group was less than that in the TP group. The VSD depth index in the MSP group was also less than that in the TP group. Associated LAVV anomalies presented more often in the MSP group. The left ventricular dimension and proportion of patients with moderate or greater LAVVR were mostly equivalent between the 2 groups.
      Table 1Patient demographic characteristics
      CharacteristicModified single-patch (n = 69)Two-patch (n = 49)P value
      Male sex28 (41)14 (29).179
      Age at ICR, d189 (121-327)167 (121-342).770
      Weight at ICR, kg5.3 (4.3-6.2)4.8 (4.0-6.7).592
      Trisomy 2137 (54)40 (82).002
      Patent left superior vena cava9 (13)2 (4).119
      Coarctation or interruption of aorta11 (16)1 (2).014
      Mechanical ventilatory support3 (4)4 (8).447
      Rastelli type.019
       A51 (74)26 (53)
       C18 (26)23 (47)
      Initial pulmonary artery banding24 (35)15 (31).635
      Echocardiographic data before ICR
       VSD depth, mm7.3 ± 2.58.9 ± 2.5<.001
       VSD depth index, mm/m225.1 ± 10.03.8 ± 8.7.002
       LVEDD, mm22.7 ± 4.022.3 ± 4.2.644
       LVEDD Z score−0.7 ± 2.1−0.8 ± 2.5.820
       Moderate or greater LAVVR12 (17)6 (12).444
       LAVV anomaly9 (13)1 (2).044
      Data are presented as median (interquartile range) or n (%) or mean (±SD). ICR, Intracardiac repair; VSD, ventricular septal defect; LVEDD, left ventricular end-diastolic diameter; LAVVR, left atrioventricular valve regurgitation; LAVV, left atrioventricular valve.

      Operative Data and Mortality

      Operative data are shown in Table 2. Mean aortic crossclamp and cardiopulmonary bypass time, excluding 12 patients who underwent a concomitant procedure related to coarctation or interruption of the aorta during ICR, were shorter in the MSP group.
      Table 2Perioperative and postoperative results
      CharacteristicOverallModified single-patchTwo-patchP value
      (Limited to) isolated CAVSD repairn = 106n = 58n = 48
       Aortic crossclamp time, min89 ± 2682 ± 23100 ± 28.001
       Cardiopulmonary bypass time, min128 ± 36120 ± 35137 ± 38.035
      Postoperative resultsn = 118n = 69n = 49
       Surgical reintervention
      LAVV-related8 (7)4 (6)4 (8).717
      RAVV-related1 (1)1 (1)0 (0)1.000
      LVOTO-related0 (0)0 (0)0 (0)
      Pacemaker insertion2 (2)1 (1)1 (2)1.000
       Hospital mortality2 (2)1 (1)1 (2)1.000
       Late mortality1 (0)1 (1)0 (0)1.000
       Long-term follow-up echocardiography
      Moderate or greater LAVVR27 (23)17 (25)10 (20).590
      LAVV inflow peak velocity, m/s1.2 ± 0.31.2 ± 0.31.2 ± 0.3.743
      LVOT peak velocity, m/s1.2 ± 0.31.2 ± 0.31.2 ± 0.3.405
      Data are presented as median (interquartile range) or n (%) or mean (±SD). CAVSD, Complete atrioventricular septal defect; LAVV, left atrioventricular valve; RAVV, right atrioventricular valve; LVOTO, left ventricular outlet tract obstruction; LAVVR, left atrioventricular valve regurgitation; LAVV, left atrioventricular valve; LVOT, left ventricular outflow tract.
      Hospital mortality was 1.7% (2 of 118). One patient (2 months of age; 2.8 kg) with preoperative heart failure with intubation who underwent TP as the primary ICR, died of persistent heart failure. Similarly, another patient (neonate; 3.3 kg) with preoperative heart failure with intubation, who underwent MSP as staged ICR, died of persistent heart failure. Late mortality occurred in 1 patient, who died of cerebral hemorrhage 10 months after discharge. The survival rate was 96.7% (95% CI, 92.2%-100%) overall, 96.7% (95% CI, 92.2%-100%) in the MSP group, and 98.0% (95% CI, 94.1%-100%) and 98.0% (95% CI, 94.1%-100%) in the TP group at 5 and 10 years, respectively (P = .746; Figure 1).
      Figure thumbnail gr1
      Figure 1Kaplan–Meier curves for overall survival stratified according to the type of ICR. Color shading shows the 95% confidence intervals. TP, 2-Patch repair; MSP, modified single-patch repair; ICR, Intracardiac repair.

      Functional Outcomes in the MSP and TP Groups

      Reoperations on the basis of the surgical approach are summarized in Table 2. The criteria for reoperations included severe LAVVR or left ventricular outflow tract (LVOT) peak pressure gradient ≥50 mm Hg.
      • Stout K.K.
      • Daniels C.J.
      • Aboulhosn J.A.
      • Bozkurt B.
      • Broberg C.S.
      • Colman J.M.
      • et al.
      2018 AHA/ACC guideline for the management of adults with congenital heart disease: a report of the American College of Cardiology/American Heart Association Task Force on clinical practice guidelines.
      Among the entire cohort, no reoperation was related to LVOT obstruction (LVOTO), and 8 (7%) patients required LAVV-related reoperations (4 patients each in the MSP and TP groups). Freedom from LAVV-related reoperation was observed in 94.2% (95% CI, 88.7%-99.7%) and 94.2% (95% CI, 88.7%-99.7%) in the MSP group, and 91.7% (95% CI, 83.9%-99.5%) and 91.7% (95% CI, 83.9%-99.5%) in the TP group at 5 and 10 years, respectively (P = .659; Figure 2, A).
      Figure thumbnail gr2
      Figure 2Kaplan–Meier curves for functional outcomes stratified according to the type of ICR. A, Freedom from LAVV-related reoperation. B, Freedom from moderate or greater LAVVR. Color shading shows the 95% confidence intervals. LAVV, Left atrioventricular valve; MSP, modified single-patch; TP, 2-patch; ICR, intracardiac repair; LAVVR, left atrioventricular valve regurgitation.
      All patients underwent postoperative echocardiography at the latest follow-up. The incidence of moderate or greater LAVVR was comparable between the 2 groups (MSP: 17 of 69 [25%], TP: 10 of 49 [20%]). Other variables, including LAVV inflow peak velocity and LVOT peak velocity, were also comparable. Freedom from moderate or greater LAVVR was 82.9% (95% CI, 73.7%-92.1%) and 76.2% (95% CI, 65.0%-87.4%) in the MSP group, and 91.7% (95% CI, 83.9%-99.5%) and 91.7% (95% CI, 83.9%-99.5%) in the TP group at 5 and 10 years, respectively (P = .009; Figure 2, B).

      Type of Procedure and Effect of VSD Depth on Late LAVVR

      In the MSP group without LAVV anomaly, the ROC curve analysis revealed that the VSD depth was strongly associated with moderate or greater postoperative LAVVR, with the best cutoff at 10.9 mm (area under the curve: 0.742; 95% CI, 0.574-0.910; P = .013). In the TP group, however, the VSD depth was only minimally associated with moderate or greater postoperative LAVVR (area under the curve: 0.598; 95% CI, 0.370-0.827; P = .362). The VSD depth was plotted and stratified according to the presence of LAVV anomaly, type of ICR, and postoperative LAVVR (Figure 3). Apparently, the calculated best cutoff value was only applicable to the MSP group without LAVV anomaly.
      Figure thumbnail gr3
      Figure 3Scatter plots of the VSD depth stratified according to the presence of LAVV anomaly, type of ICR, and postoperative LAVVR. Solid and dashed lines show the best cutoff value (11 mm) of the VSD depth, which is only applicable to the MSP group without LAVV anomaly. LAVVR, Left atrioventricular valve regurgitation; TP, 2-patch repair; MSP, modified single-patch repair; ICR, intracardiac repair; VSD, Ventricular septal defect; LAVV, left atrioventricular valve.
      The whole cohort was further divided into 4 groups stratified according to the combination of the type of ICR and VSD depth, defining the VSD depth >11 mm as deep VSD and ≤11 mm as shallow VSD. Freedom from moderate or greater LAVVR at the 10-year follow-up visit was 92.0% (95% CI, 83.2%-100.0%) for the TP-shallow VSD group, 90.0% (95% CI, 71.4%-100.0%) for the TP-deep VSD group, 79.7% (95% CI, 68.7%-90.7%) for the MSP-shallow VSD group, and 50.0% (95% CI, 10.0%-90.0%) for the MSP-deep VSD group (P = .002; Figure 4). Thus, the MSP-deep VSD group showed the worst LAVV competence among these 4 groups, lower than in the other 3 groups. There was no difference among the 3 groups except in the MSP-deep VSD group (P = .238).
      Figure thumbnail gr4
      Figure 4Kaplan–Meier curves for freedom from moderate or greater LAVVR stratified according to the combination of the type of ICR and VSD depth. The dotted line shows the 95% confidence intervals. LAVVR, Left atrioventricular valve regurgitation; TP, 2-patch repair; VSD, ventricular septal defect; MSP, modified single-patch repair; ICR, intracardiac repair.

      Risk Factors for Moderate or Greater Postoperative LAVVR

      In the whole cohort, multivariate analysis indicated weight <4.0 kg, LAVV anomaly, and moderate or greater preoperative LAVVR as independent risk factors for moderate or greater postoperative LAVVR. However, MSP was not detected as a risk factor (Table 3).
      Table 3Univariate and multivariate analysis of risk factors for moderate or greater preoperative LAVVR in the whole cohort (n = 118)
      CharacteristicN (%)Univariate analysisMultivariate analysis
      HR (95% CI)P valueHR (95% CI)P value
      Weight <4.0 kg21 (18)3.435 (1.539-7.667).0037.375 (2.953-18.42)<.001
      P value < .05 (multivariate).
      Trisomy 2177 (65)0.364 (0.167-0.792).011
      Patent left superior vena cava11 (9)0.706 (0.382-1.305).267
      Coarctation or interruption of aorta12 (10)2.657 (0.771-9.153).121
      Rastelli type A77 (65)1.774 (0.714-4.411).217
      Initial pulmonary artery banding39 (33)1.560 (0.688-3.537).287
      VSD depth >11 mm15 (13)2.959 (1.301-6.732).0102.363 (0.954-5.853).063
      LAVV anomaly10 (9)9.555 (3.742-24.40)<.0016.773 (2.409-19.04)<.001
      P value < .05 (multivariate).
      Moderate or greater preoperative LAVVR18 (15)6.760 (3.067-14.90)<.0015.367 (2.242-12.85)<.001
      P value < .05 (multivariate).
      Modified single-patch69 (58)3.621 (1.326-9.888).0122.633 (0.966-7.175).058
      HR, Hazard ratio; CI, confidence interval; VSD, ventricular septal defect; LAVV, left atrioventricular valve; LAVVR, left atrioventricular valve regurgitation.
      P value < .05 (multivariate).

      Discussion

      Considering the current emphasis on better functional outcomes, our study showed excellent surgical outcomes of balanced CAVSD with a low overall mortality rate (2.5%; 3/118), infrequent reoperation related to LAVVR (6.7%; 8/118), and a low proportion of moderate or greater postoperative LAVVR (23%; 27/118) during a postoperative follow-up period of 20 years. Identified risk factors for later LAVV incompetence in the whole cohort did not involve MSP. Further, the VSD depth in the MSP group had a strong association with unfavorable valve competence on ROC analysis. At first glance, the functional outcome of TP appears to be superior to MSP; however, when stratified according to the combination of ICR type and VSD depth, only the MSP for the deep VSD group showed the stepwise decline of functional outcome, whereas the other 3 groups showed durable LAVV competence (Figure 5; Video Abstract). This implied that the functional outcomes were comparable between the groups if the VSD was relatively shallow (VSD depth ≤11 mm). These findings indicate that specific anatomy should be taken into consideration when choosing the surgical technique.
      Figure thumbnail gr5
      Figure 5When stratified according to the combination of ICR type and VSD depth, the MSP-deep VSD group showed the worst LAVV competence among the 4 groups (P = .002). The surgical approach should be selected on the basis of anatomical variations, specifically VSD depth. MSP, Modified single-patch repair; VSD, ventricular septal defect; LAVVR, left atrioventricular valve regurgitation; TP, 2-patch repair; ICR, intracardiac repair; LAVV, left atrioventricular valve.

      Postoperative LAVVR and Its Risk Factors

      Management of recurrent LAVVR in the pediatric population is especially problematic. Far from expected reverse remodeling of the ventricle and moderate LAVVR immediately after the operation leads to left ventricular failure from progressive volume overload with various alterations to the whole valve complex, such as annular dilatation, dislocation of papillary muscles, and further degenerative changes in the leaflets. Therefore, every effort should be made to avoid postoperative LAVVR before discharge, because this is reportedly a risk factor for recurrent LAVVR.
      • Stephens E.H.
      • Ibrahimiye A.N.
      • Yerebakan H.
      • Yilmaz B.
      • Chelliah A.
      • Levasseur S.
      • et al.
      Early complete atrioventricular canal repair yields outcomes equivalent to late repair.
      The etiology of postoperative LAVVR could be multifactorial and is typically due to technical issues. However, many articles have reported low body weight as an underlying issue because of the friable leaflet tissue in its original state.
      • St Louis J.D.
      • Jodhka U.
      • Jacobs J.P.
      • He X.
      • Hill K.D.
      • Pasquali S.K.
      • et al.
      Contemporary outcomes of complete atrioventricular septal defect repair: analysis of the Society of Thoracic Surgeons Congenital Heart Surgery Database.
      • Atz A.M.
      • Hawkins J.A.
      • Lu M.
      • Cohen M.S.
      • Colan S.D.
      • Jaggers J.
      • et al.
      Surgical management of complete atrioventricular septal defect: associations with surgical technique, age, and trisomy 21.
      • Dhannapuneni R.R.
      • Gladman G.
      • Kerr S.
      • Venugopal P.
      • Alphonso N.
      • Corno A.F.
      Complete atrioventricular septal defect: outcome of pulmonary artery banding improved by adjustable device.
      • Xie O.
      • Brizard C.P.
      • d’Udekem Y.
      • Galati J.C.
      • Kelly A.
      • Yong M.S.
      • et al.
      Outcomes of repair of complete atrioventricular septal defect in the current era.
      St Louis and colleagues
      • St Louis J.D.
      • Jodhka U.
      • Jacobs J.P.
      • He X.
      • Hill K.D.
      • Pasquali S.K.
      • et al.
      Contemporary outcomes of complete atrioventricular septal defect repair: analysis of the Society of Thoracic Surgeons Congenital Heart Surgery Database.
      reviewed 2399 patients with CAVSD from the Society of Thoracic Surgeons Congenital Heart Surgery Database from 2008 to 2011. They reported that risk factors for poor outcomes (mortality, complications) included early repair (<2.5 months) and low weight (<3.5 kg). Recently, some studies have advocated early repair at younger than 3 months of age, but there is a trend toward impaired long-term survival in young patients or patients who had primary ICR.
      • Buratto E.
      • Hu T.
      • Lui A.
      • Wu D.M.
      • d’Udekem Y.
      • Brizard C.P.
      • et al.
      Early repair of complete atrioventricular septal defect has better survival than staged repair after pulmonary artery banding: a propensity score-matched study.
      ,
      • Ramgren J.J.
      • Nozohoor S.
      • Zindovic I.
      • Gustafsson R.
      • Hakacova N.
      • Sjögren J.
      Long-term outcome after early repair of complete atrioventricular septal defect in young infants.
      We have been incorporating a staged surgical approach for high-risk patients, including young patients and those with low body weight because they have fragile leaflets and determining the division line of the atrioventricular valve should be accurate. The PAB does not work for the primary LAVVR but is quite effective for congestive heart failure triggered because of large VSD and the secondary LAVVR. In our cohort, 39 patients underwent primary PAB with use of a flow probe in addition to the Trusler formula to increase the blood flow through the ascending aorta by 1.5 times, resulting in no interstage mortality after PAB. With a safe and optimal alternative approach, facing a small and fragile leaflet can be avoided.
      Some researchers have reported significant preoperative LAVVR as a predisposing factor, which could be explained by LAVV anomaly or annular dilatation.
      • Mery C.M.
      • Zea-Vera R.
      • Chacon-Portillo M.A.
      • Zhu H.
      • Kyle W.B.
      • Adachi I.
      • et al.
      Contemporary outcomes after repair of isolated and complex complete atrioventricular septal defect.
      ,
      • Suzuki K.
      • Tatsuno K.
      • Kikuchi T.
      • Mimori S.
      Predisposing factors of valve regurgitation in complete atrioventricular septal defect.
      ,
      • Ten Harkel A.D.
      • Cromme-Dijkhuis A.H.
      • Heinerman B.C.
      • Hop W.C.
      • Bogers A.J.
      Development of left atrioventricular valve regurgitation after correction of atrioventricular septal defect.
      In our study, the z score of the preoperative left ventricular end diastolic diameter did not affect postoperative LAVVR. One reason for this might be the tendency to use PAB in most symptomatic neonates or early infants, which dramatically reduces the size of the ventricles. Of the 12 patients with significant preoperative LAVVR, 5 patients had an associated LAVV anomaly. Although primary LAVVR must have resulted from a certain rationale or etiology, which were undetected from clinical reports, preoperative LAVVR was a comprehensive anatomical factor associated with some type of anomaly resulting in unfavorable valve competence.
      LAVV anomaly, which has also been recognized as a risk factor for postoperative LAVVR, was identified as a risk factor in our study.
      • Mery C.M.
      • Zea-Vera R.
      • Chacon-Portillo M.A.
      • Zhu H.
      • Kyle W.B.
      • Adachi I.
      • et al.
      Contemporary outcomes after repair of isolated and complex complete atrioventricular septal defect.
      ,
      • Mery C.M.
      • Zea-Vera R.
      • Chacon-Portillo M.A.
      • Zhang W.
      • Binder M.S.
      • Kyle W.B.
      • et al.
      Contemporary results after repair of partial and transitional atrioventricular septal defects.
      • Hoohenkerk G.J.
      • Bruggemans E.F.
      • Koolbergen D.R.
      • Rijlaarsdam M.E.
      • Hazekamp M.G.
      Long-term results of reoperation for left atrioventricular valve regurgitation after correction of atrioventricular septal defects.
      • Hoohenkerk G.J.
      • Wenink A.C.
      • Schoof P.H.
      • Koolbergen D.R.
      • Bruggemans E.F.
      • Rijlaarsdam M.
      • et al.
      Results of surgical repair of atrioventricular septal defect with double-orifice left atrioventricular valve.
      They are relatively uncommon but challenging when present; hence, fine modification in addition to the standard technique is required. Other technical aspects, such as cleft closure, have not been included as a variable in this study because our institutional policy has consistently been to close the cleft. We sometimes encounter a relatively small bridging leaflet. Closing these would lead to a new tethered anterior leaflet, which is similar to the “curtain effect” in the adult cardiac mitral field.
      • Carpentier A.
      • Adams D.
      • Filsoufi F.
      Techniques in type II posterior leaflet prolapse.
      In that case, patch augmentation would be one of the options.

      MSP Versus TP

      There has long been a debate that MSP is superior to TP. Recent comparative retrospective studies with propensity score matching analysis and a single meta-analysis showed no difference between the 2 regarding mortality and reoperation.
      • Fong L.S.
      • Betts K.
      • Bell D.
      • Konstantinov I.E.
      • Nicholson I.A.
      • Winlaw D.S.
      • et al.
      Complete atrioventricular septal defect repair in Australia: results over 25 years.
      ,
      • Bell D.
      • Thakeria P.
      • Betts K.
      • Justo R.
      • Jalali H.
      • Wijesekera V.
      • et al.
      Propensity-matched comparison of the long-term outcome of the Nunn and two-patch techniques for the repair of complete atrioventricular septal defects.
      ,
      • Wu Y.
      • Kuang H.
      • Wang G.
      • Dai J.
      • Li Y.
      • Wei G.
      • et al.
      Surgical management for complete atrioventricular septal defects: a systematic review and meta-analysis.
      These studies, however, included VSD width as an anatomical variable for the matching cohort, but we identified VSD depth as a critical component for late LAVVR when MSP was used. Although direct suturing of the common atrioventricular valve leaflet to the crest of the ventricular septum offers uncomplicated manipulation, therefore minimizing crossclamp time, this might tether the bridging leaflets to some extent. Theoretically, the sole remaining concern is that coaptation between the left lateral leaflet and sutured bridging leaflets would become shallow regardless of the VSD depth. However, the extent to which the completed valve complex can tolerate distortion of the new annulus and leaflets is of concern. Backer and colleagues
      • Backer C.L.
      • Stewart R.D.
      • Bailliard F.
      • Kelle A.M.
      • Webb C.L.
      • Mavroudis C.
      Complete atrioventricular canal: comparison of modified single-patch technique with two-patch technique.
      ,
      • Backer C.L.
      • Eltayeb O.
      • Mongé M.C.
      • Costello J.M.
      No ventricular septal defect patch atrioventricular septal defect repair.
      have advocated recommending MSP when the VSD depth is 10 mm or less and that its use should be avoided in cases of VSD depth <12 mm. In our study, the best cutoff point of VSD depth for unfavorable valve competence was similarly determined to be 11 mm. Because a scooping VSD (VSD depth >11 mm) was present in only 15 (13%) of the 118 patients in the present study, most patients with CAVSD can safely benefit from MSP, which provides simpler and shorter manipulation. Because MSP can easily be taught and grasped by trainees, requiring a shorter learning curve, it could become a reproducible standard procedure.
      • Nunn G.R.
      Atrioventricular canal: modified single patch technique.
      Inadequate coaptation can occur even when TP is used with a patch that is larger or smaller than the actual VSD depth. Furthermore, suturing the atrial septal defect from the VSD patch through bridging leaflets enfolds the leaflets, especially when the suture line is reinforced, leading to reduced coaptation length.
      • Nunn G.R.
      Atrioventricular canal: modified single patch technique.
      This multiple suturing becomes particularly critical when the repair is performed for neonates or early infants, whose leaflet tissue can be characterized as flimsy.
      • Nunn G.R.
      Atrioventricular canal: modified single patch technique.
      A jungle of chordae around the crest of the ventricular septum, as seen in Rastelli A anatomy, complicates VSD patch closure and can result in entanglement or injury of the chordae.
      There are multiple mechanisms of LAVVR, as mentioned previously. Of these, surgical approach and timing of repair still play a key role as convertible factors for better and more durable LAVV competence. We found that functional outcomes were comparable between the 2 groups unless the VSD was deep. Each technique is best suited to a specific anatomy. Our results suggest that the choice of surgical technique should be determined on the basis of the anatomical suitability of each approach rather than on a decision made irrespective of structural characteristics. Neither adopting the MSP for scooping VSD nor sticking to the TP for superficial VSD with Rastelli A should be recommended, because each has its role. Applying the appropriate technique for specific anatomical characteristic creates the best functional outcomes.
      Finally, the present study presents another striking finding; a lack of LVOTO-related reoperation, which incidence has been reported from 1.3% to 3.7%.
      • Fong L.S.
      • Betts K.
      • Bell D.
      • Konstantinov I.E.
      • Nicholson I.A.
      • Winlaw D.S.
      • et al.
      Complete atrioventricular septal defect repair in Australia: results over 25 years.
      • Buratto E.
      • Lui A.
      • Hu T.
      • Naimo P.
      • Ivanov Y.
      • d’Udekem Y.
      • et al.
      Propensity score matched analysis of cleft closure in complete atrioventricular septal defect repair.
      • Bell D.
      • Thakeria P.
      • Betts K.
      • Justo R.
      • Jalali H.
      • Wijesekera V.
      • et al.
      Propensity-matched comparison of the long-term outcome of the Nunn and two-patch techniques for the repair of complete atrioventricular septal defects.
      ,
      • Ginde S.
      • Lam J.
      • Hill G.D.
      • Cohen S.
      • Woods R.K.
      • Mitchell M.E.
      • et al.
      Long-term outcomes after surgical repair of complete atrioventricular septal defect.
      According to Overman,
      • Overman D.M.
      Reoperation for left ventricular outflow tract obstruction after repair of atrioventricular septal.
      the “scooped out” interventricular septum was more common in Rastelli type C than in Rastelli type A, and thus the lateral aspect of neo-LVOT tunnel can be squashed to some extent by the MSP. Therefore, our modification that shifts the dividing line of bridging leaflets to the right side contributes to securing more room in the tunnel, as Backer and colleagues
      • Backer C.L.
      • Eltayeb O.
      • Mongé M.C.
      • Wurlitzer K.C.
      • Hack M.A.
      • Boles L.H.
      • et al.
      Modified single patch: are we still worried about subaortic stenosis?.
      previously mentioned. MSP is not a predisposing factor to LVOTO as long as it incorporates the modification technique and is used with VSD not further extending toward the outlet portion.

      Limitation

      This study has the typical limitations of any retrospective study: selection bias and lack of randomization. It was only on the basis of the data available with a few events, it is not possible to ascertain if the variables that were not included in the multivariate analysis affected the findings. Although all echocardiography had been performed by a few cardiologists specializing in echocardiography, no core labs or examiners reviewed the echocardiographic data in this study. Hence, echocardiography data might be dependent on the skills of the reader. The follow-up length was shorter in the MSP group, which might be insufficient to detect a significant difference between the 2 groups.

      Conclusions

      Postoperative LAVVR is still an obstacle to better functional outcomes and quality of life. Unless VSD is deep, MSP and TP provide similar LAVV competence. The appropriate surgical approach should be selected according to the patient's anatomy, specifically VSD depth.

      Webcast

      You can watch a Webcast of this AATS meeting presentation by going to: https://www.aats.org/resources/1488.
      Figure thumbnail fx3

      Conflict of Interest Statement

      The authors reported no conflicts of interest.
      The Journal policy requires editors and reviewers to disclose conflicts of interest and to decline handling or reviewing manuscripts for which they may have a conflict of interest. The editors and reviewers of this article have no conflicts of interest.

      Supplementary Data

      References

        • Fong L.S.
        • Betts K.
        • Bell D.
        • Konstantinov I.E.
        • Nicholson I.A.
        • Winlaw D.S.
        • et al.
        Complete atrioventricular septal defect repair in Australia: results over 25 years.
        J Thorac Cardiovasc Surg. 2020; 159: 1014-1025
        • Buratto E.
        • Lui A.
        • Hu T.
        • Naimo P.
        • Ivanov Y.
        • d’Udekem Y.
        • et al.
        Propensity score matched analysis of cleft closure in complete atrioventricular septal defect repair.
        Ann Thorac Surg. 2022; 113: 1553-1562
        • Bell D.
        • Thakeria P.
        • Betts K.
        • Justo R.
        • Jalali H.
        • Wijesekera V.
        • et al.
        Propensity-matched comparison of the long-term outcome of the Nunn and two-patch techniques for the repair of complete atrioventricular septal defects.
        Eur J Cardiothorac Surg. 2020; 57: 85-91
        • Airaksinen R.
        • Mattila I.
        • Jokinen E.
        • Salminen J.
        • Puntila J.
        • Lehtinen M.L.
        • et al.
        Complete atrioventricular septal defect: evolution of results in a single center during 50 years.
        Ann Thorac Surg. 2019; 107: 1824-1830
        • Mery C.M.
        • Zea-Vera R.
        • Chacon-Portillo M.A.
        • Zhu H.
        • Kyle W.B.
        • Adachi I.
        • et al.
        Contemporary outcomes after repair of isolated and complex complete atrioventricular septal defect.
        Ann Thorac Surg. 2018; 106: 1429-1437
        • Wilcox B.R.
        • Jones D.R.
        • Frantz E.G.
        • Brink L.W.
        • Henry G.W.
        • Mill M.R.
        • et al.
        Anatomically sound, simplified approach to repair of “complete” atrioventricular septal defect.
        Ann Thorac Surg. 1997; 64: 487-493
        • Nicholson I.A.
        • Nunn G.R.
        • Sholler G.F.
        • Hawker R.E.
        • Cooper S.G.
        • Lau K.C.
        • et al.
        Simplified single patch technique for the repair of atrioventricular septal defect.
        J Thorac Cardiovasc Surg. 1999; 118: 642-646
        • Backer C.L.
        • Stewart R.D.
        • Bailliard F.
        • Kelle A.M.
        • Webb C.L.
        • Mavroudis C.
        Complete atrioventricular canal: comparison of modified single-patch technique with two-patch technique.
        Ann Thorac Surg. 2007; 84: 2038-2046
        • Lopez L.
        • Colan S.D.
        • Frommelt P.C.
        • Ensing G.J.
        • Kendall K.
        • Younoszai A.K.
        • et al.
        Recommendations for quantification methods during the performance of a pediatric echocardiogram: a report from the Pediatric Measurements Writing Group of the American Society of Echocardiography Pediatric and Congenital Heart Disease Council.
        J Am Soc Echocardiogr. 2010; 23: 465-495
        • Lange R.
        • Guenther T.
        • Busch R.
        • Hess J.
        • Schreiber C.
        The presence of Down syndrome is not a risk factor in complete atrioventricular septal defect repair.
        J Thorac Cardiovasc Surg. 2007; 134: 304-310
        • Stout K.K.
        • Daniels C.J.
        • Aboulhosn J.A.
        • Bozkurt B.
        • Broberg C.S.
        • Colman J.M.
        • et al.
        2018 AHA/ACC guideline for the management of adults with congenital heart disease: a report of the American College of Cardiology/American Heart Association Task Force on clinical practice guidelines.
        Circulation. 2019; 139: 698-800
        • Stephens E.H.
        • Ibrahimiye A.N.
        • Yerebakan H.
        • Yilmaz B.
        • Chelliah A.
        • Levasseur S.
        • et al.
        Early complete atrioventricular canal repair yields outcomes equivalent to late repair.
        Ann Thorac Surg. 2015; 99: 2109-2115
        • St Louis J.D.
        • Jodhka U.
        • Jacobs J.P.
        • He X.
        • Hill K.D.
        • Pasquali S.K.
        • et al.
        Contemporary outcomes of complete atrioventricular septal defect repair: analysis of the Society of Thoracic Surgeons Congenital Heart Surgery Database.
        J Thorac Cardiovasc Surg. 2014; 148: 2526-2531
        • Atz A.M.
        • Hawkins J.A.
        • Lu M.
        • Cohen M.S.
        • Colan S.D.
        • Jaggers J.
        • et al.
        Surgical management of complete atrioventricular septal defect: associations with surgical technique, age, and trisomy 21.
        J Thorac Cardiovasc Surg. 2011; 141: 1371-1379
        • Dhannapuneni R.R.
        • Gladman G.
        • Kerr S.
        • Venugopal P.
        • Alphonso N.
        • Corno A.F.
        Complete atrioventricular septal defect: outcome of pulmonary artery banding improved by adjustable device.
        J Thorac Cardiovasc Surg. 2011; 141: 179-182
        • Xie O.
        • Brizard C.P.
        • d’Udekem Y.
        • Galati J.C.
        • Kelly A.
        • Yong M.S.
        • et al.
        Outcomes of repair of complete atrioventricular septal defect in the current era.
        Eur J Cardiothorac Surg. 2014; 45: 610-617
        • Buratto E.
        • Hu T.
        • Lui A.
        • Wu D.M.
        • d’Udekem Y.
        • Brizard C.P.
        • et al.
        Early repair of complete atrioventricular septal defect has better survival than staged repair after pulmonary artery banding: a propensity score-matched study.
        J Thorac Cardiovasc Surg. 2021; 161: 1594-1601
        • Ramgren J.J.
        • Nozohoor S.
        • Zindovic I.
        • Gustafsson R.
        • Hakacova N.
        • Sjögren J.
        Long-term outcome after early repair of complete atrioventricular septal defect in young infants.
        J Thorac Cardiovasc Surg. 2021; 161: 2145-2153
        • Suzuki K.
        • Tatsuno K.
        • Kikuchi T.
        • Mimori S.
        Predisposing factors of valve regurgitation in complete atrioventricular septal defect.
        J Am Coll Cardiol. 1998; 32: 1449-1453
        • Ten Harkel A.D.
        • Cromme-Dijkhuis A.H.
        • Heinerman B.C.
        • Hop W.C.
        • Bogers A.J.
        Development of left atrioventricular valve regurgitation after correction of atrioventricular septal defect.
        Ann Thorac Surg. 2005; 79: 607-612
        • Mery C.M.
        • Zea-Vera R.
        • Chacon-Portillo M.A.
        • Zhang W.
        • Binder M.S.
        • Kyle W.B.
        • et al.
        Contemporary results after repair of partial and transitional atrioventricular septal defects.
        J Thorac Cardiovasc Surg. 2019; 157: 1117-1127
        • Hoohenkerk G.J.
        • Bruggemans E.F.
        • Koolbergen D.R.
        • Rijlaarsdam M.E.
        • Hazekamp M.G.
        Long-term results of reoperation for left atrioventricular valve regurgitation after correction of atrioventricular septal defects.
        Ann Thorac Surg. 2012; 93: 849-855
        • Hoohenkerk G.J.
        • Wenink A.C.
        • Schoof P.H.
        • Koolbergen D.R.
        • Bruggemans E.F.
        • Rijlaarsdam M.
        • et al.
        Results of surgical repair of atrioventricular septal defect with double-orifice left atrioventricular valve.
        J Thorac Cardiovasc Surg. 2009; 138: 1167-1171
        • Carpentier A.
        • Adams D.
        • Filsoufi F.
        Techniques in type II posterior leaflet prolapse.
        in: Carpentier A. Adams D.H. Filsoufi F. Carpentier’s Reconstructive Valve Surgery: From Valve Analysis to Valve Reconstruction. Saunders/Elsevier, 2010: 117
        • Wu Y.
        • Kuang H.
        • Wang G.
        • Dai J.
        • Li Y.
        • Wei G.
        • et al.
        Surgical management for complete atrioventricular septal defects: a systematic review and meta-analysis.
        Pediatr Cardiol. 2020; 41: 1445-1457
        • Backer C.L.
        • Eltayeb O.
        • Mongé M.C.
        • Costello J.M.
        No ventricular septal defect patch atrioventricular septal defect repair.
        Oper Tech Thorac Cardiovasc Surg. 2015; 20: 279-292
        • Nunn G.R.
        Atrioventricular canal: modified single patch technique.
        Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu. 2007; 10: 28-31
        • Ginde S.
        • Lam J.
        • Hill G.D.
        • Cohen S.
        • Woods R.K.
        • Mitchell M.E.
        • et al.
        Long-term outcomes after surgical repair of complete atrioventricular septal defect.
        J Thorac Cardiovasc Surg. 2015; 150: 369-374
        • Overman D.M.
        Reoperation for left ventricular outflow tract obstruction after repair of atrioventricular septal.
        Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu. 2014; 17: 43-47
        • Backer C.L.
        • Eltayeb O.
        • Mongé M.C.
        • Wurlitzer K.C.
        • Hack M.A.
        • Boles L.H.
        • et al.
        Modified single patch: are we still worried about subaortic stenosis?.
        Ann Thorac Surg. 2015; 99: 1671-1675

      Linked Article

      • Commentary: Defining the limits of the modified single-patch technique
        The Journal of Thoracic and Cardiovascular SurgeryVol. 165Issue 2
        • Preview
          The pediatric cardiac surgery group from Okayama, Japan, has provided for us a review that aids in the understanding of the limitations of the modified single-patch technique.1 The modified single-patch technique is no longer a new operation, having been first described independently by Ben Wilcox from North Carolina in 19972 and Graham Nunn from Sydney, Australia, in 1999.3 The operation has been the subject of countless reviews heralding its advantages and results in comparison with the previous standard operation the double-patch technique.
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