Further Evolution of the Delamination Technique for Very Small Pulmonary Valves in the Primary Correction of Tetralogy of Fallot

Objective: The deleterious effects for the outcome after primary correction of tetralogy of Fallot (TOF) using a transannular patch (TAP) leading to right ventricular dilatation and at least right and left ventricular failure are well known. This led to the adoption of the delamination technique to our treatment strategy. Thus, the proportion of TAP was significantly decreased, especially for pulmonary valves larger than a z-score of −2.5. To preserve the valve function with even smaller valves, we developed a standardized patch extension of the aforementioned method.

Methods: For each primary correction since November 2016, a commissurotomy of the valve was done first and then, if necessary, the leaflets were delaminated. If the ring was still too narrow afterward (< 40 mm Hg max.), only the pulmonary valve ring was transected and the existing area of the leaflets lengthened with a single triangular patch, which was sutured to build a commissure to the patch extension of the main pulmonary trunk.

Results: A total of 49 patients since November 2016 had a primary correction. Since January 2018, in four patients with a pulmonary valve ring smaller than a z-score of −2.5, the new patch technique, additionally to the delamination, prevented a TAP. Thus, the proportion of valve-sparing operations could be increased again from 58 to 72%. All patients were extubated in the operating room and had an uncomplicated course. The valves showed a low amount of regurgitation and residual stenosis during follow-up.

Conclusion: With the new standardized patch technique as an extension of the delamination technique, the proportion of transannular patch corrections in the primary correction of TOF could be even more reduced, which could further decrease the frequency of necessary valve implantations in patients with tetralogy of Fallot.