End-diastolic flow reversal limits the efficacy of pediatric intra-aortic balloon pump counterpulsation.

BACKGROUND: Counterpulsation with an intra-aortic balloon pump (IABP) has not achieved the same success or clinical use in pediatric patients as in adults. In a pediatric animal model, IABP efficacy was investigated to determine whether IABP timing with a high-fidelity blood pressure signal may improve counterpulsation therapy versus a low-fidelity signal. METHODS: In Yorkshire piglets (n = 19; weight, 13.0 ± 0.5 kg) with coronary ligation-induced acute ischemic left ventricular failure, pediatric IABPs (5 or 7 mL) were placed in the descending thoracic aorta. Inflation and deflation were timed with traditional criteria from low-fidelity (fluid-filled) and high-fidelity (micromanometer) blood pressure signals during 1:1 support. Aortic, carotid, and coronary hemodynamics were measured with pressure and flow transducers. Myocardial oxygen consumption was calculated from coronary sinus and arterial blood samples. Left ventricular myocardial blood flow and end-organ blood flow were measured with microspheres. RESULTS: Despite significant suprasystolic diastolic augmentation and afterload reduction at heart rates of 105 ± 3 beats per minute, left ventricular myocardial blood flow, myocardial oxygen consumption, the myocardial oxygen supply/demand relationship, cardiac output, and end-organ blood flow did not change. Statistically significant end-diastolic coronary, carotid, and aortic flow reversal occurred with IABP deflation. Inflation and deflation timed with a high-fidelity versus low-fidelity signal did not attenuate systemic flow reversal or improve the myocardial oxygen supply/demand relationship. CONCLUSIONS: Systemic end-diastolic flow reversal limited counterpulsation efficacy in a pediatric model of acute left ventricular failure. Adjustment of IABP inflation and deflation timing with traditional criteria and a high-fidelity blood pressure waveform did not improve IABP efficacy or attenuate flow reversal. End-diastolic flow reversal may limit the efficacy of IABP counterpulsation therapy in pediatric patients with traditional timing criteria. Investigation of alternative deflation timing strategies is warranted.

Technique of single-stage repair of coarctation of the aorta with ventricular septal defect.

The results of single-stage and two-stage repair of coarctation of the aorta (CoA) with ventricular septal defect (VSD) have improved, but the optimal treatment strategy remains controversial. This article emphasizes the technical details for performing the single-stage repair of CoA with VSD and compares the results of this technique with the two-stage approach. A retrospective analysis of 46 patients who underwent completed surgical repair of CoA with VSD at Children's Hospital of Michigan, either using the single-stage (N=23) or the two-stage (N=23) techniques, was performed. The postoperative complications, hospital mortality, freedom from cardiac re-interventions, and actuarial survival were the same in both groups. The advantages of single-stage over two-stage repair include an earlier age at completion of repair, fewer operations, and fewer incisions. The one disadvantage of a single-stage repair was the increased need for delayed sternal closure compared with the two-stage approach, but this disadvantage has been neutralized in the recent era.

Single-stage versus 2-stage repair of coarctation of the aorta with ventricular septal defect.

OBJECTIVE: The results of single-stage and 2-stage repair of coarctation of the aorta with ventricular septal defect have improved, but the optimal treatment strategy remains controversial. This study compares our results with these 2 approaches. METHODS: We performed a retrospective analysis of 46 patients, 23 with single-stage repair and 23 with 2-stage repair, who underwent completed surgical treatment of coarctation of the aorta with a ventricular septal defect at the Children's Hospital of Michigan between March 1994 and June 2006. RESULTS: The average number of operations in the single-stage group was 1.5 +/- 0.6, and in the 2-stage group it was 2.2 +/- 0.4 (P < or = .0001). Postoperative complications were similar, except for the number of planned reoperations to perform delayed sternal closure in the single-stage operation (n = 7) compared with the 2-stage operation (n = 1, P = .023). The patient age in the single-stage group at the time of discharge (completed repair time) was a median of 39.0 days (range, 19-250 days) compared with a median of 113.0 days (range, 26-1614 days) in the 2-stage group after stage 2 (P < or = .0001). Freedom from cardiac reintervention was 89.8% in the single-stage group versus 84.9% in the 2-stage group (P = .33). The hospital mortality was 4.4% (1 patient) in each group. The actuarial survival rate was 95.7% in the single-stage group versus 90.6% in the 2-stage group (P = .38). CONCLUSIONS: The advantages of single-stage over 2-stage repair of a ventricular septal defect with coarctation of the aorta include an earlier age at completion of repair, fewer operations, and fewer incisions. Postoperative complications and hospital mortality are similar. The one disadvantage of a single-stage repair was the increased need for delayed sternal closure compared with the 2-stage approach.