Surgical repair of complete atrioventricular canal defects in infancy. Twenty-year trends
F L Hanley1, K N Fenton, R A Jonas
1Department of Cardiovascular Surgery, Children's Hospital, Harvard Medical School, Boston, Mass.
Insights
Perioperative mortality for complete atrioventricular canal defect significantly decreased due to improved surgical techniques and experience. Left atrioventricular valve regurgitation remains a challenge, requiring further research for complete elimination.
Area of Science:
- Pediatric Cardiology
- Congenital Heart Disease Surgery
- Cardiovascular Research
Background:
- Complete atrioventricular canal defect (CAVC) is a complex congenital heart malformation.
- Historically, perioperative mortality for CAVC repair in infancy was high.
- Significant advancements in surgical management are expected to have reduced mortality over time.
Purpose of the Study:
- To identify factors contributing to improved perioperative mortality in CAVC patients.
- To analyze trends in patient-related, morphologic, and procedural variables over a 20-year period.
- To assess the impact of surgical experience on outcomes for CAVC repair.
Main Methods:
- Retrospective analysis of 301 infant CAVC cases (1972-1992).
- Examination of 46 variables associated with perioperative death and reoperation.
- Multivariate logistic regression to identify independent risk factors for mortality.
Main Results:
- Operative mortality decreased from 25% (pre-1976) to 3% (post-1987).
- Palliative procedures and reoperations for most residual lesions decreased significantly.
- Left atrioventricular valve regurgitation persisted as a challenge, with reoperation rates reduced but not eliminated (7% in recent years).
- Earlier year of operation, double-orifice atrioventricular valve, and residual regurgitation were risk factors for death.
Conclusions:
- Improved surgical experience and technical precision are key drivers of reduced mortality and reoperation rates for CAVC.
- Left atrioventricular valve regurgitation remains a significant postoperative complication requiring further investigation.
- Enhanced understanding of atrioventricular valve variability is crucial for eliminating residual valve dysfunction.
Abstract:
Case histories of 301 patients with complete atrioventricular canal defect presenting to our institution in infancy between January 1972 and January 1992 were reviewed with the purpose of identifying the factors responsible for the observed improvement in perioperative mortality over this time period. A retrospective analysis of hospital records examined 46 patient-related, morphologic, procedure-related, and postoperative variables for associations with perioperative death and reoperation. Operative mortality decreased significantly over the period of the study from 25% before 1976 to 3% after 1987 (p < 0.0001). A number of the 46 variables examined showed trends over time that were similar to that for mortality. Palliative procedures decreased over time. Reoperation for most residual lesions also decreased to the degree that they were essentially eliminated in recent years. The exception to this was reoperation for postoperative left atrioventricular valve regurgitation, which also decreased but remained at 7% in recent years. Both technical and support-related procedural variables showed no trends over time, with the exception of the performance of left atrioventricular valve annuloplasty, which increased over time. Closure of the left-sided cleft was performed in 61% of the patients, with no trend over time. Annuloplasty and cleft closure were not associated with less postoperative left atrioventricular valve regurgitation, fewer reoperations, or lower mortality. Multivariate logistic regression analysis identified only earlier year of operation, the presence of double-orifice left atrioventricular valve, and postoperative residual regurgitation of the left atrioventricular valve as risk factors for death. Experience-related improvements in technical precision achieved over time best account for the reduction in the rate of reoperation for most types of residual lesions and also for the reduction in mortality. The only residual lesion that has not been essentially completely eliminated is left atrioventricular valve regurgitation, with reoperation for this lesion having been reduced in recent years, but not eliminated. Improved understanding of the structural and functional variability of the atrioventricular valve in this lesion may be necessary before postoperative dysfunction of this valve can be completely eliminated.
