Background
The decision to preserve the pulmonary valve during intracardiac repair of Tetralogy of Fallot [TOF] is traditionally based on the intra-operative measurement of pulmonary annulus by a Hegar dilator as per Rowlatt’s table. We sought to evaluate if there can be flexibility in not using a transannular patch repair in Indian population with mildly hypoplastic pulmonary annulus.
Methods
Over a 1 year period 20 cases of TOF with a pre-operative diagnosis of mildly hypoplastic pulmonary annulus (Z < 0 but ≥ −4) and who at surgery, after pulmonary valvotomy accepted a maximum Hegar dilator of one size less than the recommended minimum (group I), were treated with valve sparing procedure and compared with 23 similar cases, in whom an elective trans-annular incision was used (group II).
Results
5 patients had to be converted from a valve sparing repair to a trans-annular one, because of unacceptably high right ventricular pressures or hemodynamic instability on coming off cardiopulmonary bypass. The immediate post-operative mean Right Ventricular Outflow Tract (RVOT) gradients were significantly higher in group I compared to group II. Early morbidity including Intensive Care Unit (ICU) stay and incidence of right ventricular diastolic dysfunction was increased in group I. There was no difference in the immediate and mid term survival as well as the last echocardiographically estimated mean right ventricular pressures in the two groups.
Conclusion
Patients of TOF with a mildly hypoplastic pulmonary annulus can be safely managed by a pulmonary annulus enlarging approach. We believe in such patients a lesser risk lies in inserting a trans-annular patch. However the immediate and mid term survival is not different between annulus preserving and trans-annular approach.