Very Promising Early Results with the New Valve Sparing Delamination Technique for Primary Repair of Tetralogy of Fallot

Objective: The increasing experience in repair and follow up of tetralogy of Fallot(TOF), reported in many publications, have shown that transannular patch repair (TAP) resulting in pulmonary regurgitation(PR), might lead to right ventricular dilation and concomitant deleterious effects, e.g., right and also left ventricular dysfunction, with the need for repeated reinterventions. This is also confirmed by our own experience, which comprises of 502 TOF repairs from 1995 to 2005 (n = 216, TP1) and from 2005 to 2016 (n = 286, TP2). Over the years the percentage of TAP repair decreased from 68.5% in TP1 to 55.2% in TP2 (freedom from reoperation 79.7% ± 2.9 in TP1 vs. 84.5% ± 7.1 in TP2). This was due to continuous refinement of RVOT repair techniques aiming at limiting the rate of TAP. Most recently, to lower the amount of TAP repairs even more, we added since Nov 2016 to our armamentarium the delamination technique (DL), published recently by the group of Padua.

Methods: Then we retrospectively analyzed the outcome of those patients operated on since Nov 2016 (n = 27), using DL whenever technically possible, comparing two groups. The valve could be preserved in 16 patients (valve sparing group, VS group), of which 12 were operated with the new DL technique. 11 Patients needed TAP repair (TAP group). We compared rate of early extubation, grade of PR and residual gradient in the VS and TAP group patients.

Results: There was no significant difference in age, weight, z-score and diameter of pulmonary valve annulus and median follow up time, between the two groups. Percentage of TAP was decreased to 41.7%. All patients with valve sparing techniques were postoperatively extubated in the operation theater versus 54.4% of the TAP patients. In the VS group 93.8% had mild or no PR, whereas 72.7% of the TAP group had a free PR, a highly significant difference (p < 0.0001). There was no difference in residual RVOT gradient (26.6 mm Hg ± 5.5 for TAP group versus 27.8 ± 3.8 mm Hg for the VS group.

Conclusion: The delamination technique is safe and allows preservation of the pulmonary valve in a significant number of patients. Improvements in outcome after primary repair of tetralogy of Fallot regarding postoperative period and pulmonary valve function are promising. Further studies should aim at confirming these short term results.