Surgical management of complete atrioventricular septal defects. A twenty-year experience

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

Background:

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

Methods:

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

Results:

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

Conclusions:

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

Canadian Cardiovascular Society 2022 Guidelines for Cardiovascular Interventions in Adults With Congenital Heart Disease

Interventions in adults with congenital heart disease (ACHD) focus on surgical and percutaneous interventions in light of rapidly evolving ACHD clinical practice. To bring rigour to our process and amplify the cumulative nature of evidence ACHD care we used the ADAPTE process; we systematically adjudicated, updated, and adapted existing guidelines by Canadian, American, and European cardiac societies from 2010 to 2020. We applied this to interventions related to right and left ventricular outflow obstruction, tetralogy of Fallot, coarctation, aortopathy associated with bicuspid aortic valve, atrioventricular canal defects, Ebstein anomaly, complete and congenitally corrected transposition, and patients with the Fontan operation. In addition to tables indexed to evidence, clinical flow diagrams are included for each lesion to facilitate a practical approach to clinical decision-making. Excluded are recommendations for pacemakers, defibrillators, and arrhythmia-directed interventions covered in separate designated documents. Similarly, where overlap occurs with other guidelines for valvular interventions, reference is made to parallel publications. There is a paucity of high-level quality of evidence in the form of randomized clinical trials to support guidelines in ACHD. We accounted for this in the wording of the strength of recommendations put forth by our national and international experts. As data grow on long-term follow-up, we expect that the evidence driving clinical practice will become increasingly granular. These recommendations are meant to be used to guide dialogue between clinicians, interventional cardiologists, surgeons, and patients making complex decisions relative to ACHD interventions.

Contemporary outcomes after pulmonary artery banding in complete atrioventricular septal defect

BACKGROUND

This study investigated the clinical outcomes and the effect of band tightness on outcome after pulmonary artery banding (PAB) in patients with complete atrioventricular septal defect (AVSD).

METHODS

From 2000 through 2019, among 133 patients with isolated complete AVSD pursuing biventricular repair, 34 patients (25.6%) who underwent PAB were included in this study. Factors associated with adverse outcome, which was defined as prolonged stay in the intensive care unit (ICU) (> 10 days), were analysed using multiple logistic regression model. Receiver operating characteristic (ROC) analysis was performed to identify a threshold band tightness for adverse outcome.

RESULTS

The median age and weight were 43 days and 3.6kg, respectively. There were 4 early deaths. The median ICU stay was 8 days. Twenty-eight patients (28/34, 82.4%) underwent corrective surgery 10 months (IQR 7∼12 months) after PAB. In multivariable analysis, indexed band diameter was identified as a factor associated with adverse outcome (odds ratio 1.60, 95% confidence interval 1.03-2.48; p=0.035). ROC analysis indicated 22.2 mm/m² of indexed PAB diameter measured at discharge as a threshold band tightness for adverse outcome (area under curve 0.871, p<0.001). The level of B-type natriuretic peptide similarly decreased after PAB regardless of band tightness, although the probability of worsening in atrioventricular valve regurgitation (AVVR) was significantly decreased in patients with tighter band (p=0.027).

CONCLUSIONS

PAB is a viable option for patients with early presenting complete AVSD. Tighter PAB might be beneficial for early postoperative outcomes and preventing progression of AVVR in complete AVSD.

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.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Outcomes of surgical repair of complete atrioventricular canal defect in patients younger than 2 years of age

BACKGROUND

Early surgical management of complete atrioventricular (AV) canal defect is the optimal treatment option. Since the published evidence on outcomes is inconclusive, we retrospectively studied the outcomes of patients in our institution.

OBJECTIVE

Study outcomes of complete AV canal repair.

DESIGN

Retrospective, descriptive.

SETTINGS

Single institute.

PATIENTS AND METHODS

Medical records of patients under 2 years of age who underwent complete AV canal repair from January 2004 to December 2014 were retrospectively reviewed.

MAIN OUTCOME MEASURES

Pre- and postoperative morbidity and mortality.

SAMPLE SIZE

140 patients.

RESULT

The median (IQR) age at the time of surgery was 5.4 (3.9-8.2) months. Down syndrome was diagnosed in 98 (70%) of patients. AV valve regurgitation was found preoperatively in 129 (92%) and postoperatively in 135 (96%) patients. There was a significant association between preoperative pulmonary hypertension and the development of pulmonary hypertension in the postoperative period ( P=.04). Thirty-three patients needed reoperation. Arrhythmia was found in 19 patients, 16 of whom required pacemaker insertion. Seven patients died (5%).

CONCLUSION

The presence of preoperative and postoperative AV valve regurgitation was common in this cohort but did not significantly affect patient survival. Our findings suggest an acceptable outcome for repair of complete AV septal defect with few complications postoperatively.

LIMITATION

Retrospective in single institute.

CONFLICT OF INTEREST

None.

Long-term outcomes in patients who underwent surgical correction for atrioventricular septal defect

Objective:

The follow-up results of patients operated for atrioventricular septal defect (AVSD) during 1996–2016 at Başkent University are presented.

Methods:

Data obtained from hospital records consists of preoperative echocardiographic and angiographic details, age and weight at surgery, operative details, Down syndrome presence, postoperative care details, early postoperative and latest echocardiographic findings and hospitalization for reintervention.

Results:

A total of 496 patient-files were reviewed including 314 patients (63.4%) with complete and 181 (36.6%) with partial AVSD (48.4% of all patients had Down syndrome). Atrioventricular (AV) valve morphology was Rastelli type A in 92.2%, B in 6.5%, and C in 1.3% of patients. The operative technique used was single-patch in 21.6% (108), double-patch in 25.8% (128), and modified single-patch (Wilcox) in 52.5% (260) of patients. The follow-up time was 37.79±46.70 (range, 0–198) months. A total of 64 patients (12.9%) had arrhythmias while in the intensive care unit; pacemaker was implanted in 12 patients. A total of 78 patients (15.7%) were treated for pulmonary hypertensive crisis. The early morbidity and mortality in the postoperative first month were calculated as 38% and 10%, and the late morbidity and mortality (>1 month) were calculated as 13.1% and 1.9%, respectively. The rate of reoperation in our cohort was 8.9%.

Conclusion:

Although the early morbidity and mortality are low in AVSD operations, the rate of reoperations for left AV valve insufficiency are still high. Although Down syndrome is not a risk factor for early mortality, the co-morbid factors, such as longer postoperative mechanical ventilator or inotropic support, lead to higher risk for morbidity. The frequency of pulmonary hypertension and consequent complications are also high.

Surgical Repair of Complete Atrioventricular Septal Defect

Between January 1988 and March 1996, 40 patients underwent repair of complete atrioventricular septal defect with a two-patch technique and routine atrioventricular valve cleft closure. The mean age of the patients was 10.8 ± 6.9 months and the mean weight was 6.6 ± 2.6 kg. Twenty-three had Down's syndrome and 13 had coexisting cardiac anomalies. Preoperative angiography and echocardiography revealed mild atrioventricular valve regurgitation in 22 patients, moderate regurgitation in 16, and severe regurgitation in the other 2. The mortality was 12.5% (4 early and 1 late deaths). The major cause of death was pulmonary hypertensive crisis. Reoperation was necessary in 3 patients; 2 had atrioventricular valve annuloplasty and one had prosthetic valve replacement. All 3 survived reoperation. Echocardiography at a mean of 32 ± 20 months postoperatively showed mild left atrioventricular valve regurgitation in 32 patients and moderate regurgitation in 3. Management of postoperative pulmonary hypertensive crisis and repair of complete atrioventricular septal defect before the development of high pulmonary vascular resistance may reduce the mortality of this surgical procedure.

Influence of CHDs on psycho-social and neurodevelopmental outcomes in children with Down syndrome

OBJECTIVE

To evaluate the family psycho-social outcomes of children with Down syndrome and atrioventricular septal defect, and examine the impact of these variables on the child's neurodevelopmental outcome.

METHODS

This was a cross-sectional study that consisted of 57 children with Down syndrome - 20 cases and 37 controls - of ~12-14 months of age. In both groups, we assessed the development of the child, the quality of the child's home environment, and parenting stress.

RESULTS

Compared with the Down syndrome without CHD group, the atrioventricular septal defect group revealed lower scores in all developmental domains, less optimal home environments, and higher parental stress. Significant differences in development were seen in the areas of cognition (p=0.04), expressive language (p=0.05), and gross motor (p<0.01). The Home Observation for Measurement of the Environment revealed significant differences in emotional and verbal responsiveness of the mother between the two groups. The Parenting Stress Index revealed that the Down syndrome with atrioventricular septal defect group had a significantly higher child demandingness subdomain scores compared with the Down syndrome without CHD group.

CONCLUSIONS

The diagnosis of a CHD in addition to the diagnosis of Down syndrome may provide additional stress to the child and parents, elevating parental concern and disrupting family dynamics, resulting in further neurodevelopmental deficits. Finding that parental stress and home environment may play a role in the neurodevelopmental outcomes may prompt new family-directed interventions and anticipatory guidance for the families of children with Down syndrome who have a CHD.

Contemporary outcomes of complete atrioventricular septal defect repair: analysis of the Society of Thoracic Surgeons Congenital Heart Surgery Database

OBJECTIVE

Contemporary outcomes data for complete atrioventricular septal defect (CAVSD) repair are limited. We sought to describe early outcomes of CAVSD repair across a large multicenter cohort, and explore potential associations with patient characteristics, including age, weight, and genetic syndromes.

METHODS

Patients in the Society of Thoracic Surgeons Congenital Heart Surgery Database having repair of CAVSD (2008-2011) were included. Preoperative, operative, and outcomes data were described. Univariate associations between patient factors and outcomes were described.

RESULTS

Of 2399 patients (101 centers), 78.4% had Down syndrome. Median age at surgery was 4.6 months (interquartile range, 3.5-6.1 months), with 11.8% (n = 284) aged ≤ 2.5 months. Median weight at surgery was 5.0 kg (interquartile range, 4.3-5.8 kg) with 6.3% (n = 151) < 3.5 kg. Pulmonary artery band removal at CAVSD repair was performed in 122 patients (4.6%). Major complications occurred in 9.8%, including permanent pacemaker implantation in 2.7%. Median postoperative length of stay (PLOS) was 8 days (interquartile range, 5-14 days). Overall hospital mortality was 3.0%. Weight < 3.5 kg and age ≤ 2.5 months were associated with higher mortality, longer PLOS, and increased frequency of major complications. Patients with Down syndrome had lower rates of mortality and morbidities than other patients; PLOS was similar.

CONCLUSIONS

In a contemporary multicenter cohort, most patients with CAVSD have repair early in the first year of life. Prior pulmonary artery band is rare. Hospital mortality is generally low, although patients at extremes of low weight and younger age have worse outcomes. Mortality and major complication rates are lower in patients with Down syndrome.

Surgical outcome of reoperation due to left atrioventricular valve regurgitation after previous correction of complete atrioventricular septal defect

OBJECTIVES

The aims of this study were to evaluate the early and late outcomes in patients undergoing reoperation due to left atrioventricular valve regurgitation (LAVVR) after initial complete repair (ICR) of complete atrioventricular septal defect (CAVSD).

MATERIALS AND METHOD

Between January 1990 and April 2013, 45 consecutive patients underwent reoperation due to severe LAVVR. The mean age was 7.5 ± 6.2 years. Associated LAVV malformations were found in 22 (49%) patients and associated cardiac malformations in 18 (40%). The mean follow-up was 6.8 ± 2.6 years.

RESULTS

LAVV repair was possible in all patients. There were two hospital deaths (4.5%). Ten patients (22%) required a second reoperation due to severe LAVVR at mean 7.5 ± 8.4 months after the first reoperation. The actuarial overall survival and free-reoperation survival rates at one, three, and five years were 95.4%, 92.8%, and 92.8% and 89%, 80.5%, and 72%, respectively. Multivariate analysis revealed that the associated cardiac malformations, LAVV leaflet prolapse or detachment from the septal patch, associated LAVV malformations, and post-first correction LAVVR grade ≥ 2 were strong predictors for poor overall free-reoperation survival in patients undergoing reoperation due to LAVVR after ICR of various forms of ACVSD.

CONCLUSIONS

Patients with severe LAVVR post-ICR of CAVSD may undergo reoperation with acceptable postoperative mortality and morbidity; however, they are at an increased risk for developing postoperative LAVVR and subsequent reoperation.

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.

Routine leaflet augmentation of left atrioventricular valve in the repair of atrioventricular septal defect

INTRODUCTION

A better understanding of the morphology of complete atrioventricular septal defects (CAVSD) has impacted on surgical techniques and results. On some occasions the leaflet tissue is deficient and repair becomes difficult which leads to atrioventricular valve (AVV) regurgitation following the surgical repair of the AVSD.

OBJECTIVES

This study was conducted to evaluate a modified technique in which two patches where used to close the complete atrioventricular septal defect (CAVSD) with augmentation of the left atrioventricular valve (AVV) with the ventricular septal defect (VSD) patch.

METHODS

The technique was performed on 105 infants with CAVSD at a mean age of 11.7 ± 23 months (median 5.7, range 1-135). Both superior and inferior bridging leaflets are divided routinely to expose the VSD. An autologous pericardial patch, sized precisely, is sutured to the ventricular septum. A 3-4 mm of extra patch is fashioned beyond the plane of the annulus and sutured to the divided leaflet of the left AVV. A second autologous pericardial atrial patch is attached to the body of the VSD patch at the plane of the annulus allowing 3-4 mm of the VSD patch to augment the left AV valve.

RESULTS

There was one early death among these infants. At early postoperative echo all infants had no significant residual lesions. The contribution of the patch-augmented left AV valve to competency is clearly seen by two-dimensional echocardiography. At a mean follow up of 27 ± 10 months there were two late deaths with normal last echocardiography. There were only two children who progressed to severe left AV valve regurgitation needing reoperations.

CONCLUSIONS

This modified technique yields good anatomical repair. Allowing reconstruction of both AV valves independent of the other and is in particular helpful in cases of deficient left AVV tissue.

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.

Tetralogy of Fallot with atrioventricular septal defect: surgical strategies for repair and midterm outcome of pulmonary valve-sparing approach

Repair for tetralogy of Fallot (TOF) with complete atrioventricular septal defect (CAVSD) has been reported with good early and intermediate outcomes. Morbidity, however, remains significantly high. To date, repair of CAVSD/TOF using a pulmonary valve-sparing technique (PVS) and freedom from valve reoperation are not well defined. A study was undertaken to investigate outcomes. This study was conducted in as a retrospective investigation. Between January 1988 and December 2008, 13 consecutive patients with CAVSD/TOF were identified, and their records were reviewed retrospectively. Of these 13 patients, 9 had Rastelli type C CAVSD. Trisomy 21 was present in 9 cases (69 %; 7 with type C). Five patients had received a systemic-to-pulmonary shunt (SPS) before complete repair at a mean age 1.7 ± 0.6 months. All the patients survived until complete repair. At complete CAVSD/TOF repair, AVSD was corrected with a two-patch technique in all patients. For eight patients (61.5 %), PVS was used. The remaining five patients had transannular patch (TAP) repair. The mean age at complete repair was 6.3 ± 2.4 months. At complete repair, the mean cardiopulmonary bypass time was 173.5 ± 30.6 min, and the cross-clamp time was 134.7 ± 28.8 min. There was one hospitalization and no late deaths. The median follow-up period was 9.2 years [interquartile range (IQR), 4.7-13.3 years]. The actuarial survival was 90.0 ± 9.5 % at 1 year, 90 ± 9.5 % at 5 years, and 90 ± 9.5 % at 8 years. Of the 12 survivors, 6 had some reintervention during the follow-up period. Within the first 11 years after complete repair, two patients underwent left atrioventricular (AV) valve repair, and one patient had right AV valve repair. Two patients had residual VSD closure. Four patients underwent the first right ventricular outflow tract (RVOT) reintervention for critical insufficiency or stenosis at a mean interval of 6 ± 21) months. One patient had a second RVOT reoperation. Findings showed that CAVSD/TOF with PVS was related to significantly higher freedom from RVOT reintervention (100 % at 1, 5, and 8 years compared with 80 ± 17.9 % at 1 year, 60 ± 21.9 % at 5 years, and 40 ± 21.9 % at 8 years for CAVSD/TOF using TAP; P < 0.05). No patient who underwent PVS had left ventricular outflow tract obstruction requiring reoperation. Overall freedom from any reintervention was 90.9 ± 8.6 % at 1 year, 71.6 ± 14.0 % at 5 years, and 53.7 ± 8.7 % at 8 years in this group of patients. Correction of TOF with CAVSD can be performed at low risk with favorable intermediate-term survival and satisfactory freedom from reoperation. Use of TAP can be avoided in almost two thirds of patients and may influence freedom from early RVOT reintervention.

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

OBJECTIVE

The most common reason for late surgical reintervention after repair of complete atrioventricular canal defects is the development of left atrioventricular valve regurgitation. We sought to determine the changes in left atrioventricular valve geometry after surgical repair that may predispose to regurgitation.

METHODS

Atrioventricular valve measurements were obtained by 2-dimensional echocardiography at 3 different time points (preoperative, early postoperative, and midterm postoperative [6-12 months]). Left atrioventricular valve annulus area and left ventricular volume were calculated; vena contracta of the regurgitant jet orifice was measured. All measurements were normalized relative to an appropriate power of body surface area.

RESULTS

From January 2000 to January 2008, 101 patients with complete atrioventricular canal repair were included. Left atrioventricular valve annulus was noted to remodel from an elliptical shape to a circular shape after surgery. Left atrioventricular valve annulus area increased early postoperatively (systole: 4.1 ± 0.2 cm(2)/m(2) vs 6.1 ± 0.3 cm(2)/m(2), P < .001; diastole: 7.2 ± 0.4 cm(2)/m(2) vs 10.0 ± 0.5 cm(2)/m(2), P < .001, pre- vs postoperative, respectively). This increase was sustained in the midterm postoperative period (systole: 6.1 ± 0.3 cm(2)/m(2), P = .85, vs diastole: 10.0 ± 0.4 cm(2)/m(2), P = .78, early vs midterm postoperative). Left ventricular volume increased in the early and midterm postoperative periods compared with preoperative (systole: 16.9 ± 1.2 mL/m(2) vs 26.2 ± 1.7 mL/m(2), P < .001; diastole: 35.0 ± 2.4 mL/m(2) vs 52.5 ± 3.2 mL/m(2), P < .001).

CONCLUSIONS

Complete atrioventricular canal repair leads to left atrioventricular valve annular shape change with increased area and circular shape. The change in left atrioventricular valve annulus shape appeared to be mainly due to increased circumference in the posterior free wall of the annulus. These findings may provide a mechanism for the progression of central regurgitation seen after complete atrioventricular canal repair and a potential solution.

Canadian Cardiovascular Society 2009 Consensus Conference on the management of adults with congenital heart disease: shunt lesions

With advances in pediatric cardiology and cardiac surgery, the population of adults with congenital heart disease (CHD) has increased. In the current era, there are more adults with CHD than children. This population has many unique issues and needs. Since the 2001 Canadian Cardiovascular Society Consensus Conference report on the management of adults with congenital heart disease, there have been significant advances in the field of adult CHD. Therefore, new clinical guidelines have been written by Canadian adult CHD physicians in collaboration with an international panel of experts in the field. Part I of the guidelines includes recommendations for the care of patients with atrial septal defects, ventricular septal defects, atrioventricular septal defects and patent ductus arteriosus. Topics addressed include genetics, clinical outcomes, recommended diagnostic workup, surgical and interventional options, treatment of arrhythmias, assessment of pregnancy risk, and follow-up requirements. The complete document consists of four manuscripts, which are published online in the present issue of The Canadian Journal of Cardiology. The complete document and references can also be found at www.ccs.ca or www.cachnet.org.

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.

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.

Effectiveness of balloon valvuloplasty for palliation of mitral stenosis after repair of atrioventricular canal defects

Closure of a mitral valve (MV) cleft, small left-sided cardiac structures, and ventricular imbalance all may contribute to mitral stenosis (MS) after repair of atrioventricular canal (AVC) defects. MV replacement is the traditional therapy but carries high risk in young children. The utility of balloon mitral valvuloplasty (BMV) in postoperative MS is not established and may offer alternative therapy or palliation. Since 1996, 10 patients with repaired AVC defects have undergone BMV at a median age of 2.5 years (range 8 months to 14 years), a median of 2 years after AVC repair. At catheterization, the median value of mean MS gradients was 16 mm Hg (range 12 to 22) and was reduced by 34% after BMV. Before BMV, there was mild mitral regurgitation in 9 of 10 patients, which increased to severe in 1 patient. All patients were alive at follow-up (median 5.4 years). Repeat BMV was performed in 4 patients, 10 weeks to 18 months after initial BMV. One patient underwent surgical valvuloplasty; 3 underwent MV replacement 2, 3, and 28 months after BMV. In the 6 patients (60%) with a native MV at most recent follow-up (median 3.2 years), the mean Doppler MS gradient was 9 mm Hg, the median weight had doubled, and weight percentile had increased significantly. In conclusion, BMV provides relief of MS in most patients with repaired AVC defects; marked increases in mitral regurgitation are uncommon. Because BMV can incompletely relieve obstruction and increase mitral regurgitation, it will not be definitive in most patients but will usually delay MV replacement to accommodate a larger prosthesis.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Echocardiographic evaluation and surgical implications of common atrioventricular canal defects with absent or diminutive ostium primum defect

Common atrioventricular canal defects without ostium primum defects are rare, and their accurate identification has important surgical implications. Retrospective echocardiographic database review identified subjects with common atrioventricular canal defects with absent or diminutive ostium primum defects. Surgical reports and initial and postoperative echocardiograms were reviewed to identify the imaging planes necessary to characterize this anomaly and the surgical challenges imposed by the diagnosis. Fourteen subjects were identified (93% with trisomy 21) with either absent (n = 6) or diminutive (n = 8) ostium primum defects. Malaligned conal septum was present in 50% of subjects with absent primum defects and 12.5% of subjects with diminutive defects. Immediate or long-term complications of the 11 postoperative patients included atrioventricular block (n = 4) and moderate (n = 5) or severe (n = 3) mitral regurgitation. In conclusion, echocardiographic features for the identification of common atrioventricular canal defects with absent or diminutive ostium primum defects are described. Surgical challenges involve attaining adequate exposure of the mitral component and achieving mitral valve competence.

Mid-to-long term follow-up after surgical repair of atrioventricular septal defect with common atrioventricular junction and ventricular shunting associated with tetralogy of Fallot

OBJECTIVES

Our aim is to describe our surgical approach in dealing with patients having atrioventricular septal defect with common atrioventricular junction and ventricular shunting associated with tetralogy of Fallot over the last 8 years, and to present our results in mid-to-long term follow-up.

METHODS

Between November 1995 and January 2004, we performed surgical correction in 8 consecutive children with atrioventricular septal defect, common atrioventricular junction, interventricular shunting, and associated tetralogy of Fallot. The age at surgical correction varied from 8 months to 20 years, with a mean of 45 months, and standard deviation of 74 months. A palliative systemic-to-pulmonary shunt had previously been performed in 3 patients. Follow-up ranged from 57 to 135 months, with a mean of 93.5 months, and standard deviation of 32 months. We used a two-patch technique to repair of the atrioventricular septal defect, and a pericardial transjunctional patch for relief of the obstruction in the right ventricular outflow tract.

RESULTS

There were no deaths, nor reoperations either in the postoperative period or during follow-up. All patients are asymptomatic, or in the second class created by the New York Heart Association. The mean period of cardiopulmonary by-pass was 136 minutes, and the mean stay in hospital was 11.8 days. At the last examination, pulmonary valvar insufficiency was considered severe in 2 patients, and moderate in another 2. No patient developed more than a trace of regurgitation across the reconstituted left atrioventricular valve.

CONCLUSIONS

The two-patch technique, associated with ventriculotomy and a transjunctional pulmonary patch is safe and efficient when correcting atrioventricular septal defect associated with tetralogy of Fallot, resulting in good mid-to-long term clinical outcomes.

Unidirectional Monovalve Homologous Aortic Patch for Repair of Ventricular Septal Defect With Pulmonary Hypertension

BACKGROUND

Severe pulmonary hypertension is a common complication of congenital cardiac defects with large left to right shunt, and the closure of a large ventricular septal defect (VSD) with elevated pulmonary vascular resistance (PVR) is associated with significant morbidity and mortality. A unidirectional monovalve homologous aortic patch was designed to close the large VSD with severe pulmonary hypertension in an effort to decrease the morbidity and mortality.

METHODS

Twenty-seven patients (mean age, 15.0 +/- 5.6 years) with large VSD with severe pulmonary hypertension (pulmonary vascular resistance, 15.2 +/- 3.8 Wood units) were repaired with a unidirectional monovalve homologous aortic patch. According to body surface area and the preoperative arterial oxygen saturation, the monovalve homologous aortic patches were fenestrated on the aortic wall with a diameter of 4 to 8 mm.

RESULTS

Two patients died of pulmonary hypertensive crisis and cardiac arrest postoperatively. All of the survival patients were followed up (5 months to 10 years) and the cardiopulmonary function was well improved with no late death. Obvious opening and closing of the monovalve was detected by early postoperative echocardiography in seven patients. A small amount of right to left shunt was detected in three patients three months after operation, and in two of them the shunt still existed three years after operation.

CONCLUSIONS

Closure of a large VSD in patients with severe pulmonary hypertension could be performed with low morbidity and mortality when a unidirectional monovalve homologous aortic patch was used and the long-term result was satisfactory.