The effect of surgical technique, age, and Trisomy 21 on early outcome of surgical management of complete atrioventricular canal defect

BACKGROUND

The optimal timing, surgical technique, and the influence of Trisomy 21 on the outcome of surgical repair of Complete Atrioventricular Canal Defect remains uncertain. We reviewed our experience in the repair of CAVC to identify the influence of these factors on operative outcomes.

METHODS

A prospective study included 70 patients, who underwent repair of CAVC at our institute between July, 2016 and October, 2019. Primary endpoint was mortality and the secondary endpoint was a degree of left atrioventricular valve regurgitation.

RESULTS

No significant difference was noted between patients operated on, at the first 6 months of age versus later, regarding mortality or LAVV regurgitation. Surgical repair by modified single-patch technique showed a significant reduction in bypass time (71.13 ± 13.507 min versus 99.19 ± 27.092 min, p-value = 0.001). Compared to closure of cleft only, posterior annuloplasty used for repair of LAVV resulted in significant reduction in the occurrence of post-operative valve regurgitation during the early period (LAVV 2 + 43 versus 7 %, p-value = 0.03) and at 6 months of follow-up (LAVV 2 + 35.4 versus 0 %, p-value = 0.01), respectively.

CONCLUSIONS

Early intervention, in the first 6 months in patients with CAVC by surgical repair gives comparable acceptable results to later repair; Trisomy 21 was not found to be a risk factor for early intervention. Repair of common AV valve by cleft closure with posterior LAVV annuloplasty showed better results with a significant decrease in post-operative LAVV regurgitation and early mortality in comparison to the closure of cleft only.

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.

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 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.