Browsing by Author "Nolte, Lars"

The mortality rate of neonatal piglets after heart surgery is high. Searching for a possible explanation for the death of neonatal piglets early after cardiopulmonary bypass, we analyzed hemodynamic parameters regarding survival and non-survival. Initially, 10 neonatal piglets (younger than 7 days) were connected to cardiopulmonary bypass (CPB). The mean body weight was 2.98+/-0.44 kg. Exposure of the heart was performed through a median sternotomy. After connection to the CPB, the piglets were cooled to 32 degrees C core temperature before the ascending aorta was cross-clamped and the heart arrested (90?min). Thereafter, piglets were re-warmed to 37 degrees C and separated from CPB. During follow-up, the piglets did not receive inotropic support or vasopressors. Piglets who survived at least 2h after termination of CPB were included in the study for further data analysis (n=9). Five piglets died 2.5 to 4.0 h (median: 3.5 h) after CPB; these piglets formed the non-survivors group. Four animals survived the complete follow-up of 6 h after CPB and formed the survivors group. Regarding contractility (dP/dtmax, dP/dtmax/P, and wall thickening) there were not statistically significant differences between the groups. Non-survivors showed prolonged decrease of mean arterial pressure of more than 20% of baseline values, corresponding with a value of below 30?mm?Hg. In conclusion, the death of neonatal piglets early after cardiopulmonary bypass was not determined by low output.

Animal models are still essential for studying effects of cardiopulmonary bypass. We describe modifications in cannulation technique for a neonatal piglet model, which may also serve as an "everyday" technique in congenital cardiac surgery (age of animals < 7 days; mean body weight 2.9 +/- 0.5 kg). Surgical approach through median sternotomy and cardiopulmonary bypass was established by cannulating right atrium and ascending aorta with a modified aortic root cannula. Left ventricular venting was performed placing a cannula into the apex and connecting this to the venous drainage line. The described technique has been applied in 19 cases, all but one were without technical problems.

Cardiac function and hemodynamics are frequently decreased during the first hours after heart surgery, resulting in inotropic support for treatment and prevention of further hemodynamic deterioration. The aim of this study was analysis of hemodynamics of neonatal piglets who survived early postoperative course after cardiopulmonary bypass (CPB) and cardioplegic arrest without the use of inotropic drugs. Newborn piglets (younger than 7 days) were placed on mild hypothermic CPB (32 degrees C) for 180 minutes, including 90 minutes of cardioplegic arrest. Hemodynamics were examined after, termination of CPB and none of the animals received any inotropic support. After 6 hours, survived animals were euthanized (CPB group, n = 4). For control, neonatal piglets were examined for the same time interval after surgery without CPB (control group, n = 3). Systolic left-ventricular pressure increased after CPB, mean arterial blood pressure and amplitude of left ventricular wall thickness decreased. Compared with control group, systolic left-ventricular pressure in CPB group was higher (p < 0.05). Present data demonstrated hemodynamic depression after cardiac procedures in survived neonatal animals. Although the effects may not be solely attributed to CPB and myocardial ischemia effects may be potentiate by CPB. ASAIO journal 2009; 55:93-95.