Björn Peters

Comparison of different near‐infrared spectroscopic cerebral oxygenation indices with central venous and jugular venous oxygenation saturation in children

Background:  We compared two different near‐infrared spectrophotometers: cerebral tissue oxygenation index (TOI) measured by NIRO 200 and regional cerebral oxygenation index (rSO2) measured by INVOS 5100 with venous oxygen saturation in the jugular bulb (SjO2) and central SvO2 from the superior caval vein (SVC) during elective cardiac catheterization in children.

Absence of Pulmonary Artery Growth After Fontan Operation and Its Possible Impact on Late Outcome

BACKGROUND The purpose of this study was to evaluate the development of the pulmonary arteries (PAs) after Fontan operation in children at long term. METHODS Thirty-five patients in whom Fontan operation was performed at median age of 4.2 years (range, 1.5 to 16.1 years) underwent angiographic measurements of the central and lower lobe PA diameter before Fontan operation and during the median follow-up of 4.6 years (range, 1.4 to 15.1 years). The median patient age at follow-up was 8.6 years (range, 3.4 to 27.2 years). Body surface area-dependent PA index and lower lobe index were calculated, and preoperative and follow-up values were compared. A correlation between the PA indices and the duration of the follow-up as well as between PA indices and the outcome was investigated. RESULTS Although percentile parallel somatic development of the children could be documented by body surface area measurements (0.62 to 0.93 m(2) during the follow-up; p < 0.001), the PA showed no gain in diameter at all. The PA index and lower lobe index (preoperative median, 261 and 138 mm(2)/m(2), respectively) decreased significantly during the follow-up period (median, 177 and 109 mm(2)/m(2);p < 0.001). The lowest PA index was noted in patients who had the longest follow-up (R = 0.5; p = 0.009). We found a correlation between a low PA index and an unfavorable Fontan outcome (n = 10, p = 0.002). CONCLUSIONS Growth of PAs after Fontan operation is clearly reduced despite somatic growth. This phenomenon may lead to an increase in pulmonary vascular resistance and could be a limit for optimal Fontan circulation in grown children in the long term.

Long-term cardiopulmonary exercise capacity after modified Fontan operation

OBJECTIVE Early circuit separation enhances the long-term success of Fontan haemodynamics. To test this hypothesis, we analysed the postoperative cardiopulmonary capacity in children and adults. PATIENTS Spiroergometry was performed at least twice in 43 patients with a median age of 14 (range: 7-43) years, with a median time interval of 4.6 (1.1-10.4) years between early and late testing. Twenty-eight patients had been operated on in childhood and 15 as adults. The exercise capacity (W(max)) and oxygen consumption capacity (VO(2max)) were compared between children and adults. RESULTS The VO(2max) in children early postoperatively was better than in adults (median 27.9 vs 22.9, p=0.032). Both VO(2max) (median 30.1 ml min(-1) kg(-1) vs 16.9 ml min(-1)kg(-1), p<0.001), and W(max) (median 2.2 W kg(-1) vs 1.4 W kg(-1), p<0.001) were significantly better in children late after surgery. In the patient group as a whole, there was a significant decrease of VO(2max) between early and later testing (median 26.5 l min(-1) kg(-1) vs 20.7 l min(-1) kg(-1), p<0.001). CONCLUSIONS Fontan palliation in early childhood results in better cardiopulmonary capacity during long-term follow-up. Regular surveillance of the physical capacity by spiroergometry is indispensable for the supervision of patients with Fontan haemodynamics.

Improved early postoperative outcome for extracardiac Fontan operation without cardiopulmonary bypass: a single-centre experience

OBJECTIVES The use of modified extracardiac Fontan operation (ECFO) for total cavo-pulmonary connection allows cardiopulmonary bypass (CPB) to be avoided and seems to improve early postoperative results. We evaluated our experience with the off-pump technique for ECFO. METHODS Since 2009, the last 17 consecutive patients of 137 (median age 3.2 years, median weight 14.5 kg) in whom no intracardiac surgery was necessary underwent ECFO without CPB. The non-fenestrated graft was connected end-to-side to the pulmonary artery without bypass; subsequently temporary passive inferior vena cava (IVC)-to-atrial bypass was used for the anastomosis between IVC and graft. The perioperative and postoperative course was compared between consecutive paediatric patients operated on using the CPB vs off-pump technique. RESULTS There was no mortality in the off-pump group, with a total early mortality of 3.0%. Overall operation time for the Fontan operation using the off-pump technique was significantly reduced (160 vs 200 min, P < 0.001). The median Fontan pressure 24 and 48 h postoperatively was significantly lower in the off-pump group (P = 0.002/0.042). Duration of mechanical ventilation (9 vs 14 h, P = 0.016), pleural effusions (4 vs 8 days, P < 0.001) as well as the median intensive care unit (2 vs 4 days, P = 0.013) and hospital stay (median 10 vs 15 days, P < 0.001) was significantly shorter in patients who underwent the off-pump Fontan operation. The necessity of blood transfusions was significantly reduced with the off-pump in comparison with the on-pump technique (14 of 17 vs 34 of 84 patients, P = 0.003). CONCLUSIONS The ECFO without CPB is an established low-risk surgical procedure that improves the early postoperative course and significantly reduces the use of blood products and the duration of pleural effusions in selected patients.

Transfusion‐Free Arterial Switch Operation in a 1.7‐kg Premature Neonate Using a New Miniature Cardiopulmonary Bypass System

Abstract  In cardiac surgery, the potentially detrimental effects of transfusions on patient outcome are increasingly appreciated. Therefore, at our institution there are continuing efforts to modify our surgical, perfusion, and blood management strategies with the aim of transfusion‐free cardiac surgery even in neonates and small children. Stringent improvement of these strategies, particularly the downsizing of the cardiopulmonary bypass system, have now enabled a transfusion‐free arterial switch operation in a 1700‐gram prematurely born neonate.

Effects of incremental beta-blocker dosing on myocardial mechanics of the human left ventricle: MRI 3D-tagging insight into pharmacodynamics supports theory of inner antagonism

Beta-blockers contribute to treatment of heart failure. Their mechanism of action, however, is incompletely understood. Gradients in beta-blocker sensitivity of helically aligned cardiomyocytes compared with counteracting transversely intruding cardiomyocytes seem crucial. We hypothesize that selective blockade of transversely intruding cardiomyocytes by low-dose beta-blockade unloads ventricular performance. Cardiac magnetic resonance imaging (MRI) 3D tagging delivers parameters of myocardial performance. We studied 13 healthy volunteers by MRI 3D tagging during escalated intravenous administration of esmolol. The circumferential, longitudinal, and radial myocardial shortening was determined for each dose. The curves were analyzed for peak value, time-to-peak, upslope, and area-under-the-curve. At low doses, from 5 to 25 μg·kg(-1)·min(-1), peak contraction increased while time-to-peak decreased yielding a steeper upslope. Combining the values revealed a left shift of the curves at low doses compared with baseline without esmolol. At doses of 50 to 150 μg·kg(-1)·min(-1), a right shift with flattening occurred. In healthy volunteers we found more pronounced myocardial shortening at low compared with clinical dosage of beta-blockers. In patients with ventricular hypertrophy and higher prevalence of transversely intruding cardiomyocytes selective low-dose beta-blockade could be even more effective. MRI 3D tagging could help to determine optimal individual beta-blocker dosing avoiding undesirable side effects.

Systemic right ventricular morphology in the early postoperative course after extracardiac Fontan operation: is there still a need for special care?

Objectives We aimed to compare early postoperative outcome after extracardiac (EC) Fontan operation between patients with right (RV) or left (LV) systemic ventricles. Methods In total, 173 consecutive patients (median age 4 years, median weight 14 kg) underwent EC Fontan between 1995 and 2013. Pre- and intraoperative data as well as detailed postoperative haemodynamic variables were compared between patients with LV [ n  = 109 (63%)] and RV [ n  = 64 (37%)]. Results : RV patients showed significantly lower mean arterial (median 55 vs 59 mmHg, P  = 0.04), higher atrial (median 8 vs 6 mmHg, P  = 0.03) and comparable pulmonary pressure (median 14 vs 14 mmHg, P  = 0.7) as well as lower mean systemic perfusion pressure (median 39 vs 43 mmHg, P  = 0.03) on Day 0 after EC Fontan. They suffered from longer intubation time (median 18 vs 12 h, P  = 0.008), higher incidence of ascites (46% vs 28%, P  = 0.04) and need for dialysis (21% vs 4%, P  = 0.003). Prolonged inotropic support (25% vs 8%, P  = 0.02) and pharmacological treatment to reduce pulmonary vascular resistance (71% vs 53%, P  = 0.002) were more often used in RV patients and they showed more often supraventricular tachyarrhythmia (27% vs 5%, P  < 0.001) and a longer intensive care unit-stay (median 4 vs 3 days, P  = 0.03). However, early mortality, need for Fontan takedown, use of mechanical circulatory support, pleural effusions and hospital stay were not significantly different between both groups. Conclusions Patients with systemic RV demonstrate higher morbidity in the early postoperative course compared with patients with systemic LV anatomy and require intensified postoperative management to avoid postoperative Fontan failure.