Modified single-patch technique: Repairing complete atrioventricular septal defect

Long-Term Outcome Up To 40 Years after Single Patch Repair of Complete Atrioventricular Septal Defect in Infancy or Childhood

Objectives  Patients with repaired complete atrioventricular septal defect (CAVSD) represent an increasing portion of grown-ups with congenital heart disease. For repair of CAVSD, the single-patch technique has been employed first. This technique requires division of the bridging leaflets, thus, among other issues, long-term function of the atrioventricular valves is of particular concern.

Methods  Between 1978 and 2001, 100 consecutive patients with isolated CAVSD underwent single-patch repair in our institution. Hospital mortality was 11%. Primary endpoints were clinical status, atrioventricular valve function, and freedom from reoperation in long term. Follow-up was obtained contacting the patient and/or caregiver, and the referring cardiologist.

Results  Eighty-three patients were eligible for long-term follow-up (21.0 ± 8.7, mean ± standard deviation [21.5; 2.1–40.0, median; min–max] years after surgical repair). Actual long-term mortality was 3.4%. Quality of life (QoL; self- or caregiver-reported in patients with Down syndrome) was excellent or good in 81%, mild congestive heart failure was present in 16%, moderate in 3.6% as estimated by New York Heart Association classification. Echocardiography revealed normal systolic left ventricular function in all cases. Regurgitation of the right atrioventricular valve was mild in 48%, mild–moderate in 3.6%, and moderate in 1.2%. The left atrioventricular valve was mildly stenotic in 15% and mild to moderately stenotic in 2%; regurgitation was mild in 54%, mild to moderate in 13%, and moderate in 15% of patients. Freedom from left atrioventricular-valve-related reoperation was 95.3, 92.7, and 89.3% after 5, 10, and 30 years, respectively. Permanent pacemaker therapy, as an immediate result of CAVSD repair ( n  = 7) or as a result of late-onset sick sinus syndrome ( n  = 5), required up to six reoperations in single patients. Freedom from pacemaker-related reoperation was 91.4, 84.4, and 51.5% after 5, 10, and 30 years, respectively.

Conclusion  Up to 40 years after single-patch repair of CAVSD, clinical status and functional results are promising, particularly, in terms of atrioventricular valve function. Permanent pacemaker therapy results in a life-long need for surgical reinterventions.

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.

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.

Long-Term Outcome of Patients With Complete Atrioventricular Septal Defect Combined With the Tetralogy of Fallot: Staged Repair Is Not Inferior to Primary Repair

BACKGROUND

Primary repair is the preferred strategy for surgical treatment of complete atrioventricular septal defect combined with the tetralogy of Fallot. However, a staged approach may be preferable for very small or cyanotic infants. The long-term outcomes of infants undergoing staged vs primary repair were compared.

METHODS

Data from 47 patients with complete atrioventricular septal defect combined with the tetralogy of Fallot who were operated on at our institution between 1974 and 2013 were reviewed. The study end points were all-cause death and reoperation. The patients were classified into two groups: staged repair (SR) and primary repair (PR). The indications for staged repair were cyanosis and young age.

RESULTS

There were 22 SR and 25 PR patients. The SR patients were younger at the time of the initial operation (p = 0.001), and were more frequently cyanotic (21 SR vs 5 PR patients, p = 0.003). The 10-year survival after repair of the SR and PR patients was 78% ± 11% and 83% ± 8%, respectively (p = 0.8). No risk factors for death were identified. The 10-year freedom from reoperation for atrioventricular valve regurgitation of SR and PR patients after repair was 73% ± 12% and 71% ± 10%, respectively (p = 0.5). At least moderate atrioventricular valve regurgitation before repair was the only risk factor for reoperation (p = 0.01).

CONCLUSIONS

Cyanotic and very young children with complete atrioventricular septal defect combined with the tetralogy of Fallot who require urgent treatment have long-term outcomes after staged repair similar to those of patients who undergo primary repair. Preoperative atrioventricular valve regurgitation is associated with increased risk for reoperation over the long-term.