Temporary restriction of right ventricle-pulmonary artery conduit flow using haemostatic clips following Norwood I reconstruction: potential for improved outcomes.

Improved outcomes of the Norwood procedure in hypoplastic left heart syndrome have been achieved by the manipulation of the pulmonary:systemic flow ratio (Qp:Qs) in the early post-operative period, with focus on improving systemic perfusion. As an extension of this Qp:Qs-limiting strategy, we evolved a novel surgical technique to achieve transient flow restriction in the right ventricle-pulmonary artery (RV-PA) conduit for the first 48 h, using haemostatic clips, in a cohort of patients and compared the early outcomes with a non-clipped cohort. Clips were subsequently removed at 48 h at the time of definitive chest closure. We performed RV-PA shunt flow clipping in 37 patients; 75 historical controls had not received clips. Groups were matched for weight, size of ascending aorta, anatomy and circulatory arrest times. Thirty-day mortality was lower in the clipped cohort (2 of 37; 5.4%) versus the unclipped cohort (10 of 75; 13.3%). The minimum blood lactate levels within the first 24 h post-surgery in the unclipped group were significantly higher (P = 0.049), with a significantly lower Qp:Qs in the first 6 h in the clipped patients. These data suggest that limiting Qp:Qs in the early post-operative period following the Norwood procedure may help in the post-operative management of these difficult patients. These results warrant further study.