Is double or single patch for sinus venosus atrial septal defect repair the better option in prevention of postoperative venous obstruction?

A best evidence topic in cardiac surgery was constructed according to a structured protocol. The question addressed was, 'Is double or single patch for sinus venous atrial septal defect repair the better option in prevention of postoperative venous obstruction?' Altogether seventy nine papers were found using the reported search; ten papers were identified that provided the best evidence to answer the question. The authors, journal, date, country of publication, patient group, study type, relevant outcomes and results of were tabulated. Three hundred and thirty four patients had single-patch with 7 (2.1%) having venous obstruction (venous obstruction; defined as obstruction at the atriocaval anastomosis and/or the right superior pulmonary vein) while 130 had double-patch with 3 (2.3%) having venous obstruction. However, when the three randomised studies were reviewed, 101 had single-patch and 67 had double-patch with 7 (7%) and 4 (6%) having venous obstruction respectively. Similarly, another randomised study that considered solely the two surgical options with eighteen patients who had single-patch repair as group A and 19 patients who had double-patch repair as group B with six patients in group A and 2 patients in group B having significant superior vena cava-right atrium pressure gradient of more than 6 mmHg. Nine patients in group A had a significant gradient causing turbulence across the right superior pulmonary vein at the level of the patch, whereas no patients in group B had turbulence across the pulmonary vein. The double-patch technique technically offered better results in terms of superior vena cava narrowing and gradient across the pulmonary vein without any increase in complications. However, in order to reduce postoperative venous obstruction while using the single-patch repair method, the adoption of the transcaval approach yielded excellent results, with unobstructed pulmonary and systemic venous flow as in 141 patients who had this method of repair only one patient had venous obstruction. In conclusion, the evidence was in support of the adoption of double-patch or the use of the transcaval repair technique when the single patch technique was used as a better option to avoid venous obstruction.