Atrioventricular canal: modified single patch technique

Anatomic considerations in the management of complete atrioventricular canal

OBJECTIVE

Patients with complete atrioventricular canal have a variable clinical course prior to repair. Many patients balance their circulations well prior to elective repair. Others manifest clinically significant pulmonary over circulation early in life and require either palliative pulmonary artery banding or complete repair. The objective of this study was to assess anatomic features that impact the clinical course of patients.

METHODS

In total, 222 patients underwent complete atrioventricular canal repair between 2012 and 2022 at a single institution. Twenty-seven (12%) patients underwent either pulmonary artery banding (n = 15) or complete repair (n = 12) at less than 3 months of age (Group 1). The remaining 195 (88%) underwent repair after 3 months of age (Group 2). Patient records and imaging were reviewed.

RESULTS

The median post-operative length of stay following complete repair was 25 [7,46] days for those patients in Group 1 and 7 [5,12] days for those in Group 2 (p < 0.0001). There was relative hypoplasia of left-sided structures in Group 1 versus Group 2. Mean z-score for the ascending aorta was -1.2 (±0.8) versus -0.3 (±0.9) (p < 0.0001), the aortic isthmus was -2.1 (±0.8) versus -1.4 (±0.8) (p = 0.005). The pulmonary valve to aortic valve diameter ratio was median 1.47 [1.38,1.71] versus 1.38 [1.17,1.53] (p 0.008).

CONCLUSIONS

Echocardiographic evaluation of the systemic and pulmonary outflow of patients with complete atrioventricular canal may assist in predicting the clinical course and need for early repair vs pulmonary artery banding.

The impact of surgical repair on left ventricular outflow tract in atrioventricular septal defect with common atrioventricular valve orifice

Objective

Although a narrow left ventricular outflow tract in atrioventricular septal defect is related to its intrinsic morphology, the contribution from the repair technique remains to be quantified.

Methods

A total of 108 patients with an atrioventricular septal defect with a common atrioventricular valve orifice were divided into 2 groups: 2-patch (N = 67) and modified 1-patch (N = 41) repair. The left ventricular outflow tract morphometric was analyzed by quantifying the degree of disproportion between subaortic and aortic annular dimensions (disproportionate morphometrics ratio was defined as ≤ 0.9). Z-scores (median, interquartile range) were further analyzed in a subset of 80 patients with immediate preoperative and postoperative echocardiography. A total of 44 subjects with ventricular septal defects served as controls.

Results

Before repair, 13 patients (12%) with an atrioventricular septal defect had disproportionate morphometrics (vs 6 [14%] ventricular septal defect P = .79), but the subaortic Z-score (-0.53, -1.07 to 0.06) was lower than the ventricular septal defect (0.07, -0.57 to 1.17; P < .001). After repair, both 2-patch (8 [12%] preoperatively vs 25 [37%] postoperatively; P = .001) and modified 1-patch (5 [12%] vs 21 [51%], P < .001) procedures showed a greater degree of disproportionate morphometrics. Both 2-patch (postoperatively -0.73, -1.56 to 0.08 vs preoperatively -0.43, -0.98 to 0.28; P = .011) and modified 1-patch (-1.42, -2.63 to -0.78 vs -0.70, -1.18 to -0.25; P = .001) procedures also demonstrated lower subaortic Z-scores postrepair. The postrepair subaortic Z-scores were lower in the modified 1-patch group (-1.42 [-2.63 to -0.78]) compared with the 2-patch group (-0.73 [-1.56 to 0.08]; P = .004). Low postrepair subaortic Z-scores (<-2) were observed in 12 patients (41%) in the modified 1-patch group and 6 patients (12%) in the 2-patch group (P = .004).

Conclusions

Surgical correction resulted in greater disproportionate morphometrics seen immediately postrepair. The impact on the left ventricular outflow tract was observed in all repair techniques, with a greater burden seen after modified 1-patch repair.

Video Abstract

This morphometric study in AVSD with common atrio-ventricular valve orifice confirmed further derangements of LV outflow tract morphometrics immediately after surgical repair.

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.

Teaching the Modified Single-Patch Technique for Complete Atrioventricular Septal Defect

Understanding the morphology of atrioventricular septal defects and learning the operative strategies for their repair is one of the more difficult tasks for congenital cardiac surgery residents to master. The modified single-patch technique for several reasons lends itself to being a strategy that is relatively easy to teach residents. It has shorter cross-clamp and bypass times than the standard two-patch technique, which allows more time for the instructor to safely take the resident through the case. The steps of the operation are quite standard and broadly applicable to the wide variety of cardiac morphologies found in children with atrioventricular septal defects. The purpose of this review is to carefully point out the technical details of each step of the modified single-patch technique focusing on teaching the resident surgeon. The ease of teaching this excellent technique is just another reason to use the modified single-patch technique.

Correlation of ventricular septal defect height and outcomes after complete atrioventricular septal defect repair

 

OBJECTIVES

There are limited data available on the height of the ventricular component of the septal deficiency (VSD) in patients undergoing complete atrioventricular septal defect (CAVSD) repair. VSD height may influence optimal choice of repair strategy with potential consequences for long-term outcomes. We aimed to measure VSD height using 2-dimensional echocardiography and review its association with postoperative outcomes.

METHODS

We retrospectively reviewed the preoperative echocardiograms of 45 consecutive patients who underwent CAVSD repair between May 2010 and December 2015 at a single centre. VSD height and left ventricular length on the four-chamber view were measured. Demographic details and early and late outcomes including reoperation and long-term survival were studied.

RESULTS

Twenty patients underwent modified single-patch repair and 25 patients underwent double-patch repair of CAVSD. VSD height in the modified single-patch group ranged from 4.2 to 11.7 mm and in the double-patch group ranged from 5.1 to 14.9 mm. Nine patients had a deep ‘scoop’ with a VSD height of >10 mm, (7 double patch, 2 modified single patch). VSD height did not correlate with a specific Rastelli classification. There was no significant difference in the VSD height (P = 0.51) or the VSD height-to-left ventricular length ratio (P = 0.43) between the 2 repair groups. There was no 30-day mortality. Eight patients required reoperation; however, VSD height was not a significant predictor of reoperation (hazard ratio 0.95, 95% confidence interval 0.69–1.33; P = 0.08).

CONCLUSIONS

There was no correlation between VSD height and risk of reoperation after CAVSD repair. A deep ventricular scoop is uncommon in CAVSD patients.

Predictors of reoperation and mortality after complete atrioventricular septal defect repair

OBJECTIVES

Previous studies investigating risk factors associated with reoperation or mortality after repair of complete atrioventricular septal defect (CAVSD) often have not included sizeable cohorts undergoing modified single-patch repair. Both double patch and modified single-patch techniques have been widely used in Australia since the 1990s. Using a large multi-institutional cohort, we aimed to identify risk factors associated with reoperation or mortality following CAVSD repair.

METHODS

Between January 1990 and December 2015, a total of 829 patients underwent biventricular surgical repair of CAVSD in Australia at 4 centres. Patients with associated tetralogy of Fallot and other conotruncal abnormalities were excluded. Demographic details, postoperative outcomes including reoperation and survival, and associated risk factors were analysed.

RESULTS

Fifty-six patients (6.8%) required early reoperation (≤30 days) for significant left atrioventricular valve regurgitation or residual septal defects. Freedom from reoperation at 10, 15 and 20 years was 82.7%, 81.1% and 77%, respectively. Patients without Down syndrome and moderate left atrioventricular valve regurgitation on postoperative echocardiogram were found to be independent risk factors for reoperation. Operative mortality was 3.3%. Overall survival at 10, 15 and 20 years was 91.7%, 90.7% and 88.7%, respectively. Prior pulmonary artery banding was a predictor for mortality, while later surgical era (2010-2015) was associated with a reduction in mortality risk.

CONCLUSIONS

Improved survival in the contemporary era is in keeping with improvements in surgical management and higher rates of primary CAVSD repair over time. The presence of residual moderate left atrioventricular valve regurgitation on postoperative echocardiography is an important factor associated with reoperation and close surveillance is essential to allow timely reintervention. Primary CAVSD repair at age <3 months should be preferenced to palliation with pulmonary artery banding due to the association of pulmonary artery banding with mortality in the long-term.

Surgical Management for Complete Atrioventricular Septal Defects: A Systematic Review and Meta-Analysis

A meta-analysis is performed for a comparison of outcomes between the modified one-patch repair (MPR) and two-patch repair (TPR) for complete atrioventricular septal defects (CAVSD). Electronic databases, including PubMed, Scopus, Embase, and Cochrane Library were searched systematically for the literature which aimed mainly at comparing the therapeutic effects for CAVSD administrated by MPR and TPR. Corresponding data sets were extracted and two reviewers independently assessed the risks of bias. Meta-analysis was performed using Revman 5.3 and Stata 12.0. Fifteen studies meeting the inclusion criteria were included, involving 2076 subjects in total. It was observed that MPR was associated with shorter cardiopulmonary bypass (CPB) and aortic cross-clamp (ACC) times, as compared with TPR. However, no statistical differences were found in terms of size of ventricular septal defects (VSD), reoperation, mortality, implantation of permanent pacemakers, and length of ventilation, hospital and intensive care unit stay. As compared with TPR, MPR is superior in terms of ACC and CPB. However, with regard to reoperation, mortality, length of ventilation, ICU and hospital stay and permanent pacemakers implantation, no significant differences are found between these two procedures. MPR is likely to apply to younger infants with faster completion of surgery. Surgery is recommended between 3 and 6 months of age.

Modified Single Repair Technique for Complete Atrioventricular Septal Defect: A Propensity Score Matching Analysis

There were controversies about the priority of modified single patch (MSP) technique compared with two-patch (TP) technique for patients with complete atrioventricular septal defect (CAVSD). From 2002 to 2013, patients who diagnosed as balanced CAVSD in our institution were retrospectively included. Patients with unbalanced ventricles or associated anomalies were excluded. The primary endpoint was all-cause mortality and the secondary endpoint consist of left atrioventricular dysfunction or left atrioventricular outflow tract obstruction (LVOTO). A total of 74 patients underwent MSP repair and 102 patients underwent TP repair. After 1:1 propensity matching, there were 46 Rastelli type A CAVSD patients in each group. Patients in MSP group had shorter cardiopulmonary bypass time [median (interquartile range) 73.5 (65.5-95.0) versus 105.0 (88.8-130.0) min, P < 0.001] and aortic cross-clamp time [105.5 (90.0-128.0) versus 143.0 (122.0-184.0) min, P < 0.001]. In total, the primary endpoint occurred in 12 patients, including 2/46 (4.3%) in MSP group and 10/46 (21.7%) in TP group. That 1-year, 3-year, 5-year survival rate can be calculated as 95.6%, 95.6%, 95.6% in MSP group and 92.6%, 80.4%, 78.2% in TP group, P = 0.015. No significant statistical difference found for the secondary endpoints that 7/46 (15.2%) patients occurred moderate or severe LAVVR in MSP group versus 11/46 (23.9%) patients in TP group, P = 0.293. No LVOTO occurred in both groups. Besides the simplicity of technique, MSP technique may be safer.

Modified Single-Patch versus Two-Patch Repair for Atrioventricular Septal Defect: A Systematic Review and Meta-Analysis

BACKGROUND

We performed a meta-analysis of studies to determine whether the modified single-patch technique offers benefits when compared to the two-patch repair. The postoperative outcomes examined in this study were cardiopulmonary bypass time, cross-clamp time, duration of mechanical ventilation, intensive care unit length of stay, total hospital length of stay, need for reoperation, need for reoperation for left ventricular outflow tract obstruction or left atrioventricular valve regurgitation, need for pacemaker implantation, and mortality during follow-up.

METHODS

A review was conducted to identify studies comparing a modified single-patch repair versus two-patch repair. A fixed-effects model was utilized for end points with low heterogeneity and a random-effects model for end points with significant heterogeneity. Meta-regression was also performed to determine the influence of other factors on the variables of interest.

RESULTS

A total of 964 unique manuscripts were screened, with 10 being included in the final analyses. There were a total of 724 patients, with 353 (49%) having undergone repair utilizing a modified single-patch repair. Mean age at repair for modified single-patch repair and two-patch repair was 8.81 and 9.03 months, respectively. Significant differences were noted in cardiopulmonary bypass time and cross-clamp time with mean difference of -28.53 and -22.69 minutes, respectively. In comparison to the two-patch repair, both times were decreased in modified single-patch repair. No significant difference was noted in any other variables.

CONCLUSIONS

Modified single-patch repair for atrioventricular septal defects requires less cardiopulmonary bypass and cross-clamp time but does not significantly impact the examined postoperative outcomes.

Early and midterm outcomes of a modified single-patch technique for repairing complete atrioventricular septal defect in children and adults

OBJECTIVES

The "modified single-patch" technique (Nunn's technique) has become more widely adopted, especially in small infants with common atrioventricular septal defect (CAVSD). In this study, we retrospectively reviewed our surgical experiences of the "modified single-patch" technique with CAVSD patients, including newborns and adults, to reveal the early and midterm clinical results.

METHODS

There were 233 cases diagnosed with CAVSD undergoing biventricular repair in our hospital from June 2009 to 2016. A total of 197 cases (84.5%) with the "modified single-patch" technique were enrolled in the final analysis, including type A in 106 cases (53.8%), type B in 13 cases (6.6%), type C in 15 cases (7.6%), and intermediate type in 63 cases (32%). Major associated cardiovascular malformations included five cases of unroofed coronary sinus syndrome with LSVC (UCS), five cases of coarctation of the aorta and one case of translocation of the great artery. The median age at operation of the studied 197 cases was 44.3 ± 103.3 months (ranging from 18 days to 58 years old), including two newborns. Detailed information on the "modified single-patch" procedure was described previously, and the other cardiac malformations were repaired simultaneously with surgical repair.

RESULTS

There were 14 (7.1%) early deaths and 3 (1.5%) late deaths at 3 months and 1 year after the initial operation, respectively. The total mortality rate was 8.1%, and there was no significant difference in mortality among the different age groups (P = .291). Five patients (2.5%) underwent reoperation because of severe mitral insufficiency (MI), and another patient was reoperated for left ventricular outflow tract obstruction 3 years after the initial surgery. Long-term survival in the <3 months group was significantly lower than that in the group of older children (1-18 years old). Of the 180 survivors who were followed up for at least 1 year, the proportion of severe MI began to drop from 26.2% before the operation to 13.8% just 1-week postoperation and continued to decline to the lowest level, 3.4%, at 3 months postoperation. However, MI began to rebound at 3 months and reached 20.8% at 1-year postoperation. The rebound of MI was evident in the (3 months, 6 months) age group and the >18 years age group. However, compared to the preoperation situation, the proportion of severe tricuspid insufficiencies decreased each month from 24.8% to 0.0% until 3 months after the operation and remained at a relatively low level within 1 year after surgery.

CONCLUSIONS

In our experience, age is not a limitation of the modified single-patch technique, and patients even in adults with surgical indications can apply this technique. In older children and adults, we should pay more attention to atrioventricular valve annuloplasty. Infants may suffer from severe residual left atrioventricular valve regurgitation, especially in the <3 months age group, so we should improve postoperative follow-up work during infancy.

Modified-Single Patch vs Double Patch Repair of Complete Atrioventricular Septal Defects

Biventricular repair of complete atrioventricular septal defect (CAVSD) is largely achieved using the double-patch (DP) or modified single-patch (MSP) techniques in the current era; however, long-term results following MSP repair are not well defined. We aimed to compare long-term outcomes including reoperation and mortality after CAVSD repair using DP and MSP techniques, and identify the risk factors associated with adverse outcomes. A retrospective cohort study was performed including all patients who underwent CAVSD repair using DP and MSP techniques at our institution between 17 May 1990 and 14 December 2015. Demographic details, early (≤30 days) and late (>30 days) outcomes (reoperation, mortality) were studied. Competing risks analysis with cumulative incidence function was used for survival analyses. Overall, 273 consecutive patients underwent CAVSD repair (120 DP and 153 MSP) and 41 patients required reoperation during follow-up. Competing risks analysis showed no association between repair technique and reoperation (P = 1.0) or mortality (P = 0.9). Considering competing risks due to mortality, the cumulative incidence of reoperation at 5, 10, and 15 years was 14%, 17%, and 17% for DP and 12%, 13%, and 16% for MSP, respectively. Non-Down syndrome and moderate or greater left atrioventricular valve regurgitation were predictors for reoperation. Pulmonary artery banding was predictive of mortality, though strongly associated with earlier surgical era. Median follow-up duration was 8.0 years (interquartile range 3.9-20.8) for DP and 11.6 years (interquartile range 5.4-16.1) for MSP (P = 0.4). Event-free survival is similar after DP and MSP repair of CAVSD indicating either repair technique can be safely utilized.

A review of the Nunn modified single patch technique for atrioventricular septal defect repair

Atrioventricular septal defect (AVSD) is a common congenital cardiac surgical problem. Over the years, younger and smaller infants are having operations for this condition before irreversible cardio pulmonary changes occur. Traditionally a single or two patch techniques have been used to repair this defect. However, in the past two decades an innovative method of modified single patch technique popularized by Dr. Graham Nunn has gained worldwide popularity. This review discusses the origin, surgical principles, technique and outcomes of this method, popularly known as Nunn or Australian technique. Research comparing the modified single patch technique to classic single and double patch techniques has shown good preservation of atrioventricular valve function, no residual ventricular septal defect (VSDs), low incidence of left ventricular outflow obstruction, preserved conduction, easy reproducibility, and improved perioperative and long-term mortality.

Modified Single-Patch Technique Versus Two-Patch Technique for the Repair of Complete Atrioventricular Septal Defect: A Meta-Analysis

Technical selection for surgical repair of complete atrioventricular septal defect (CAVSD) still remains controversial. This meta-analysis aimed to compare the modified single-patch (MP) technique with the two-patch (TP) technique for patients with CAVSD. Relevant studies comparing the MP technique with the TP technique were identified through a literature search using MEDLINE, EMBASE, Google Scholar, Cochrane Library, and the China National Knowledge Infrastructure databases. The variables were ventricular septal defect (VSD) size, cardiopulmonary bypass (CBP) time, aortic cross-clamp (ACC) time, intensive care unit stay, hospital stay, and other outcomes involving mortality, left ventricular outflow tract obstruction, atrioventricular valve regurgitation, residual septal shunt, atrioventricular block, and reoperation. A random-effect/fixed-effect model was used to summarize the estimates of mean difference/odds ratio with 95% confidence interval. Subgroup analysis stratified by region was performed. Fifteen publications involving 1034 patients were included. This meta-analysis demonstrated that (1) VSD size in the MP group was significantly smaller; (2) CBP time, ACC time, and hospital stay in the MP group experienced improvement; (3) Other postoperative outcomes showed no significant differences between two groups; and (4) The trends in China and other countries were close. The MP and TP techniques had comparable outcomes; however, the MP technique was performed with significantly shorter CBP and ACC times in patients with smaller VSDs. Given this limitation of data, the results of comparison of the two techniques in patients with larger VSDs remain unknown. Further studies are needed.

Complete Atrioventricular Canal Defect: Towards a More Physiological Repair

We describe a more physiological technique of complete atrioventricular septal defect repair which restores normal heart anatomy with the offset between the insertions of the mitral and tricuspid valves. This technique overcomes the drawbacks of the previous approaches, and may improve surgical outcomes, particularly in small infants with high ventricular septal defect component or dextroposed aorta.

Repair of Complete Atrioventricular Septal Defects With Decellularized Extracellular Matrix: Initial and Midterm Outcomes

Objective:

Since April 2010, our institution has repaired complete atrioventricular septal defects (CAVSDs) with a two-patch technique utilizing CorMatrix extracellular material. This material is potentially an attractive patch because of its theorized eventual integration with the host tissue. We sought to analyze initial outcomes of CAVSD repair with CorMatrix.

Methods:

Data were collected on consecutive pediatric (age <18) patients receiving two-patch CAVSD repairs with CorMatrix at a single institution from April 2010 to July 2014. Baseline and perioperative characteristics were evaluated. Echocardiograms were evaluated in both the immediate postoperative period and the most recent postoperative follow-up. Variables analyzed included left AV valve performance, residual shunting, left ventricular outflow tract (LVOT) gradient, morbidity, and mortality.

Results:

Fifteen patients were identified. The average age at operation was 205 days, with mean follow-up time at 1,364 days. Echocardiograms revealed the following: 12 (80%) patients showed either improved or stable left AV valve performance remaining at “mild” or less insufficiency, while two (13%) declined from “none” to mild and one (7%) from mild to “severe,” which required reoperation. There was no residual shunting or LVOT obstruction at follow-up. The single (7%) reoperation was performed after three years due to left AV valve zone of apposition dehiscence. No permanent pacemakers were needed, and no deaths were reported.

Conclusion:

Our initial experience with CorMatrix in the repair of CAVSD in children has resulted in good initial and midterm outcomes. The CorMatrix patch remained stable through midterm follow-up, thus may be efficacious for use in CAVSD repair.

Surgical repair of partial atrioventricular defect

Long-term survival rate of patients operated for partial atrioventricular (AV) canal is lower than that of the general population, and late complications are relatively significant: between 10 and 30% of operated patients present with left AV valve regurgitation, and up to 25% have to be reoperated for valve repair or replacement, left ventricular outflow tract obstruction or residual atrial septal defect. Because the left AV valve regurgitation is the most common complication following surgery, technical details in the surgical management of the mitral valve are the most important aspects of this procedure; for example, the decision to close the cleft and to perform an annuloplasty. The presence of mitral valve anomalies in 7-28% of the cases complicates further the surgical management of these valves. This article will describe in detail the operative technique of partial AV canal repair, and review the relevant literature.

Surgical repair of complete atrioventricular defect (Nunn technique)

Two procedures have been traditionally used for the surgical repair of complete atrioventricular canal. The single-patch technique includes the division of valve leaflets, and the use of one patch to close the ventricular and the atrial septal defects, whereas the double-patch technique uses two separate patches, without the division of the bridging leaflets. Between 1997 and 2007, another technique emerged, the modified single-patch technique, or the 'Australian' technique, whereby the ventricular septal defect (VSD) is closed by the direct apposition of the bridging leaflets against the crest of the defect. Because of the absence of the ventricular septal patch, concerns have been raised about the possible left ventricular outflow tract obstruction (LVOTO), or atrioventricular valve (AVV) distortion, especially in case of a deep VSD, or if the defect extends superiorly. The results of the modified single-patch technique in terms of mortality, immediate and long-term AVV function and LVOTO have been similar to the standard techniques in most reports. This article will describe in detail the operative technique and review the relevant literature.

Modified single patch: are we still worried about subaortic stenosis?

BACKGROUND

When the modified single-patch technique for atrioventricular septal defect (AVSD) repair was introduced by Dr Benson Wilcox, there was concern that these patients might be at risk for late subaortic stenosis and left ventricular outflow tract obstruction (LVOTO). This review evaluated our modified single-patch population for LVOTO in the postoperative period.

METHODS

Between January 2000 and 2013, 77 infants underwent AVSD repair with a modified single-patch technique. Median age was 4.2 months, and median weight was 5 kg. Eight patients had a prior repair of coarctation of the aorta via left thoracotomy in the newborn period.

RESULTS

The median hospital stay was 10 days. No patient required a pacemaker. The mean and median follow-up times were 4.6 and 3.7 years, respectively. Only 2 patients (2.5%) required reoperation for LVOTO; both had prior repair of coarctation of the aorta (2 of 8 vs 0 of 69, p = 0.01). A discrete fibrous subaortic membrane developed in the first patient that required resection at 3 and 7 years after repair. The other patient had LVOTO from accessory chordae of the left atrioventricular valve and required mitral valve replacement 5 months after repair. One early death occurred at 4 months postoperatively due to liver failure related to hyperalimentation.

CONCLUSIONS

At intermediate term follow-up, LVOTO does not appear to be a significant postoperative issue after modified single-patch repair of AVSD. Coarctation of the aorta was the most significant predictor of late LVOTO after repair of AVSD with the modified single-patch technique.

Comparison of two surgical techniques for complete atrioventricular septal defect repair using two- and three-dimensional echocardiography

Different surgical techniques for complete atrioventricular septal defect (CAVSD) repair have been described, with the double-patch technique being most frequently employed. More recently a newer technique using a modified single-patch repair has been advocated. We hypothesized that the modified single-patch technique would result in an increased incidence of the two major post-repair comorbidities, namely, distortion of the left AV valve (LAVV) leaflets and narrowing of the left-ventricular outflow tract (LVOT). We studied 14 patients with CAVSD who underwent either traditional double-patch technique [group 1 (n = 7)] or modified single-patch technique [group 2 (n = 7)]. Preoperative and immediate postoperative two-dimensional (2D) echocardiograms, as well as follow-up 2D and three-dimensional (3D) studies, were reviewed. For group 1, the median age at repair was 4.1 months with a median duration from surgical repair and last echocardiogram of 44 months. For group 2, the median age at repair was 3 months with a median duration from surgical repair and last echocardiogram of 28 months. The two groups had similar demographics and ventricular septal defect size before surgery. For the LAVV, no significant difference was observed with respect to LAVV annulus size, tenting height, and the size of the vena contracta. Furthermore, there was no significant difference in the 2D echocardiographic areas and volumes of the LVOT between pre-repair and immediate post-repair studies for both groups. At the last evaluation, although there had been growth of the LVOT in both groups, no significant difference between areas and volumes were observed. Areas of the LVOT measured by 3D echocardiography on the final study showed no significant statistical difference between both groups. There was good correlation of the areas measured by 2D and 3D echocardiography within each group. In this small group, modified single-patch technique does not appear to tether the LAVV or promote an increase in regurgitation. In the short term, LVOT growth is unaffected, and the repair does not promote LVOT obstruction. 3D echocardiography is useful for area measurements of the LVOT and showed good correlation with areas measured by assumption of the LVOT shape as determined using 2D techniques.

Reoperation for left ventricular outflow tract obstruction after repair of atrioventricular septal

Left ventricular outflow tract obstruction (LVOTO) is an important source of morbidity and mortality after repair of atrioventricular septal defect (AVSD). The intrinsic anatomy of the left ventricular outflow tract in AVSD is complex and predisposes to the development of LVOTO. LVOTO after repair of AVSD usually involves multiple levels and sources of obstruction, and surgical intervention must address each component of the obstruction. This includes fibromuscular obstruction, septal hypertrophy, and valve related sources of obstruction. Special attention is also directed to the anterolateral muscle bundle of the left ventricle, a well defined but under recognized feature of the left ventricular outflow tract in AVSD. It is present in all patients with AVSD, and resection of a hypertrophic anterolateral muscle bundle of the left ventricle should be incorporated in all operations for LVOTO after repair of AVSD. LVOTO after repair of AVSD has several unique features that must be taken into consideration to maximize outcome after surgical intervention. These include anatomic factors, technical aspects of surgical intervention, and proper selection of the operation used for relief of LVOTO.

Modified single-patch compared with two-patch repair of complete atrioventricular septal defect

BACKGROUND

We compared the outcomes of modified single-patch and two-patch surgical repair of complete atrioventricular septal defect (CAVSD) on left ventricular outflow tract (LVOT) diameter and on left atrioventricular valve (LAVV) coaptation.

METHODS

We reviewed retrospectively postoperative 2-dimensional echocardiograms of all CAVSD patients who underwent modified single-patch or two-patch repair between 2005 and 2011. We measured the leaflet coaptation length of the LAVV in the apical four-chamber view. The LVOT was measured in the long axis view.

RESULTS

Fifty-one patients underwent CAVSD repair at a median age of 4 months (range, 1 to 9 months) (single-patch, n=29; two-patch, n=22). The images from 46 echocardiograms were adequate for analysis. Modified single-patch repair required significantly shorter bypass time (102.0±33.6 vs 152.9±39.5 minutes, p<0.001) and ischemic time (69.0±21.7 vs 106.9±29.7 minutes, p<0.001) than did two-patch repair. The indexed coaptation length of the septal and lateral leaflets was not different between single-patch and two-patch (3.1±2.3 vs 4.1±3.1 mm/m2, p=0.25; 2.3±2.3 vs 3.3±3.0 mm/m2, p=0.21). Indexed LVOT diameter was not different in the two groups (26.1±5.2 vs 28.5±7.1 mm/m2, p=0.22). There was no hospital or late death during the median follow-up time of 35 months (range, 1 to 69 months). Five patients underwent reoperation after single-patch repair (3 with residual ventricular septal defect [VSD] and LAVV regurgitation, 1 with residual VSD, 1 with pacemaker implantation). After the two-patch repair, 1 patient required reoperation for a residual VSD and right atrioventricular valve regurgitation (p=0.22).

CONCLUSIONS

The modified single-patch repair was performed with significantly shorter bypass time and myocardial ischemic time. The postoperative LVOT diameter and LAVV leaflet coaptation length were not significantly different between techniques.

Unbalanced atrioventricular septal defect: definition and decision making

Unbalanced atrioventricular septal defect is an uncommon lesion with widely varying anatomic manifestations. When unbalance is severe, diagnosis and treatment is straightforward, directed toward single-ventricle palliation. Milder forms, however, pose a challenge to current diagnostic and therapeutic approaches. The transition from anatomies that are capable of sustaining biventricular physiology to those that cannot is obscure, resulting in uneven application of surgical strategy and excess mortality. Imprecise assessments of ventricular competence have dominated clinical decision making in this regard. Malalignment of the atrioventricular junction and its attendant derangement of inflow physiology is a critical factor in determining the feasibility of biventricular repair in the setting of unbalanced atrioventricular septal defect. The atrioventricular valve index accurately identifies unbalanced atrioventricular septal defect and also brings into focus a zone of transition from anatomies that can support a biventricular end state and those that cannot.

Unbalanced atrioventricular septal defect: defining the limits of biventricular repair

Unbalanced atrioventricular septal defect (uAVSD) is a challenging lesion with suboptimal outcomes in the current era. Severe forms of uAVSD mandate univentricular repair with well-documented outcomes. Determining the feasibility of biventricular repair (BVR) in patients with moderate forms of uAVSD is difficult. Ventricular hypoplasia has traditionally formed the cornerstone of defining uAVSD. However, malalignment of the atrioventricular junction and related derangements of the anatomy and physiology of the atrioventricular inflow play a central role in establishing and sustaining a biventricular end state. Atrioventricular valve index, left ventricular inflow index, and right ventricle/left ventricle inflow angle are important recently described measures of inflow physiology. Additional patient anatomic and physiologic factors that impact BVR feasibility undoubtedly exist. A recently launched Congenital Heart Surgeons Society prospective inception cohort study will address these and other issues that impair our ability to predict BVR feasibility in uAVSD.

Outcome after repair of atrioventricular septal defect with tetralogy of Fallot

BACKGROUND

Long-term outcomes of repair of tetralogy of Fallot associated with complete atrioventricular septal defect are seldom reported. We report our survival and reintervention outcomes over a 29-year time period.

METHODS

Between March 1979 and April 2008, 61 patients with the combined cardiac defect of atrioventricular septal defect and tetralogy of Fallot were surgically managed. Trisomy 21 was present in 49 (80%) patients. Primary repair was performed in 36 patients at a median age of 9 months (range, 1 month to 16 years), whereas 25 patients had initial palliation by systemic-pulmonary shunt at a median age of 21 months (range, 0 days to 36 years). Thirty-one (51%) patients had a transannular patch. Fifty-three patients required right ventriculotomy for relief of the right ventricular outflow tract obstruction. Four patients had a right ventricle-pulmonary artery conduit with a homograft. Relationships between patient characteristics and outcome variables were examined using Kaplan-Meier survival curves; comparisons were performed using the log-rank test.

RESULTS

Median follow-up was 4.7 years. A total of 12 patients died during the course of follow-up: 4 (7%)deaths within 30 days of surgery and 8 late deaths (range, 4 months to 9.9 years after repair). Since 2000, there have been no early deaths and 1 late death, 5 months after the operation. The estimated survival at 5 years after definitive repair was 82% (95% confidence interval, 69%, 90%). Time to death was not associated with any patient or surgical variables examined. Overall, 30% of the survivors required a reoperation. The type of reoperations was on the mitral valve (4 repairs, 4 replacements) and 7 pulmonary valve replacements. We did not find an effect of era on mortality (P = .23 for comparison of 1979-1989, 1990-1999, and 2000-2008). The percentage of patients with primary repair did not change during the different quartiles. The estimated freedom from reoperation at 5 years was 80% (65%, 90%). Time to reoperation was shorter for patients with a conduit (P = .01).

CONCLUSIONS

Excellent long-term survival was achieved after repair of tetralogy of Fallot associated with complete atrioventricular septal defect. Palliation and primary repair resulted in comparable outcomes; as such, primary repair is favored. The choice of right ventricular outflow tract reconstruction affects the need for reoperation.

The current surgical perspective to repair of atrioventricular septal defect with common atrioventricular junction

Atrioventricular septal defect with common atrioventricular junction is a relatively common congenital cardiac malformation. It sometimes presents challenging surgical problems, especially when seen in combination with tetralogy of Fallot. We describe herein our current concepts regarding surgical repair of atrioventricular septal defect with and without tetralogy, discussing indications for surgery, timing, technical aspects, and outcomes.

Management of Complete Atrioventricular Canal Defect With Aortic Arch Obstruction

Patients with complete atrioventricular canal defect and aortic arch obstruction represent a particular challenge for management. The incidence is rare, so surgical experience is limited. A reasonable treatment option for newborns and young infants with competent atrioventricular valves is the staged approach, with the arch obstruction repaired first, followed at an appropriate interval by repair of the complete atrioventricular canal defect. If there is a significant degree of atrioventricular valve regurgitation, the primary single-stage correction of both aortic arch obstruction and the intracardiac malformation should be undertaken, irrespective of age. It remains to be seen whether this surgical strategy can be adopted for the entire spectrum of atrioventricular canal defect associated with arch obstruction.

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.

Repair of atrioventricular canal with double-outlet right ventricle, transposition, or truncus arteriosus

Atrioventricular canal and conotruncal anomalies are a heterogeneous group of lesions presenting unique challenges for surgical repair. These are the establishment of unobstructed pathways from left ventricle (LV) to aorta and from right ventricle (RV) to pulmonary artery, closure of the inlet ventricular septal defect (VSD) and atrial septal defect (ASD) ostium primum, and the avoidance of significant left and right atrioventricular valve (AV) regurgitation. Repair of complete atrioventricular canal (CAVC) with tetralogy of Fallot (TOF) has been most commonly achieved, either using a single-patch or a 2-patch technique. In patients with CAVC with double-outlet right ventricle (DORV) with subaortic VSD extension, the 2-patch repair is not unlike that of CAVC with TOF. However, biventricular repair is most challenging in patients with CAVC and complete origin of the aorta from the RV, as in CAVC with DORV and noncommitted VSD and those with CAVC with transposition of the great arteries (TGA) and LVOTO. The technique of VSD translocation allows anatomic biventricular repair for these particularly challenging patients. The arterial switch operation with CAVC repair can be used for patients with CAVC with DORV with subpulmonary VSD extension and CAVC with TGA without left ventricular outflow tract obstruction. Biventricular repair is achievable in most patients with balanced complete atrioventricular canal and conotruncal anomaly. The extreme heterogeneity of CAVC with conotruncal anomalies requires a highly individual approach that is tailored to the specific constellation of lesions in each patient.

Individualized Approach to Repair of Complete Atrioventricular Canal: Selective Use of the Traditional Single-Patch Technique Versus the Australian Technique

The traditional single-patch technique for repair of complete atrioventricular (AV) canal requires surgical division of the superior and inferior common leaflets. In the neonate and young infant, subsequent resuspension of very delicate AV valve tissue on the pericardial patch can be problematic. Selective application of the modified single-patch technique as described by Nunn (Australian technique) minimizes manipulation of the AV valve leaflet tissue. Previous reports have documented that since the late 1980s, the traditional single-patch approach with leaflet resuspension is possible with a mortality of 3% or less. A review of the initial 33 patients managed with the Australian technique was undertaken. The ventricular septal defect was moderate or large in 29 patients (88%). In the balanced canal subgroup, there was no early mortality; 1 patient underwent reoperative mitral repair for cleft dehiscence 1 year postoperatively, and 1 patient with heterotaxy required pacemaker implantation. In the unbalanced canal subgroup, 2 patients died perioperatively (22%). There have been no late deaths or new left ventricular outflow tract obstruction in either subgroup. Selective application of the single-patch technique currently allows excellent results for surgical repair in the neonatal period or early infancy. Even during the learning phase of the Australian technique, satisfactory results were achieved.

Challenges in delayed repair of atrioventricular septal defects

Delayed diagnosis and surgery for atrioventricular septal defects are not uncommon in the developing world. This review details the challenges faced in managing this difficult subset of patients.

The diagnostic process and perioperative and anesthetic management of an undiagnosed congenital cyanotic cardiac defect in an adult for trauma surgery

A 39-year-old patient awaiting emergency surgery due to a crush foot injury, with an undiagnosed cyanotic cardiac lesion that was diagnosed later as a complete atrioventricular canal defect, is presented. Complete atrioventricular canal defects usually present in the first few months of life and can be fatal if not treated in the first few years. Adult patients with congenital cardiac malformations seem to be at increased risk for noncardiac surgery. The diagnostic process, perioperative management, and anesthetic implications are discussed.