Influence of different flow modi during extracorporeal circulation on endothelial-derived vasoactive substances

Abstract

Influences of shear stress on endothelin (ET) as well as prostacyclin (PGF) levels are common findings in different experimental settings. Thus, plasma levels of both substances seem to be a good tool to verify if different flow modi can be produced in blood vessels by generating pulsatile flow with a roller pump. In the present study, 20 patients scheduled for elective aortocoronary bypass operation were divided into two groups at random. One group was perfused with nonpulsatile (CON-group) and the other with pulsatile flow (PULS-group) during extracorporeal circulation. ET and PGF plasma levels were monitored perioperatively together with parameters of renal function and haemodynamic data. ET values were only slightly elevated at the end of extracorporeal circulation (mean baseline value; CON 3.1 pg/ml and PULS 3.2 pg/ml; mean maximal values at the end of cardiopulmonary bypass (CPB) 4.0 pg/ml and 3.9 pg/ml respectively). Prostacylin values (median baseline values: CON 56.7 pg/ml and PULS 57.1 pg/ml) peaked at the end of operation (median CON 117.8 pg/ml and PULS 137.5 pg/ml respectively) with a subsequent small decrease. No differences between the groups could be observed at any time point with respect to vasoactive substances, urine output (CON 6.5 ml/min and PULS 6.2 ml/min) or haemodynamics during CPB. This confirms studies emphasizing that no effective microvascular pulsatile flow is generated by conventional pulsatile flow-generating devices. In the present study, normothermia and a constant flow rate were maintained during CPB. Aortic cannulae (body-surface-related not maximal large diameters) were inserted. Altering these procedures may have led to more pronounced differences between the groups. All patients had an uneventful course after the operation. Similar to other reports, the present study was not able to demonstrate any benefit of pulsatile perfusion during extracorporeal circulation.

Intra-aortic balloon pump induced pulsatile perfusion reduces endothelial activation and inflammatory response following cardiopulmonary bypass

“…Again, studies on endothelial activation following pulsatile and non-pulsatile perfusion have given contradictory results in the current literature [11][12][13][14]; some studies reported beneficial effects of pulsatile perfusion on endothelial response to CPB [12][13][14], others did not find any superiority of pulsatile CPB over nonpulsatile perfusion [11]. Despite IABP-induced pulsatile perfusion being first suggested by Pappas and co-workers in 1975 [15], literature lacks studies analyzing the endothelial response and the cytokine release following this type of perfusion or standard linear CPB.…”

“…However, pulsatile CPB still represents an open question: some studies have reported beneficial effects on microcirculation, metabolism, and organ functions [3,4], and our group has previously demonstrated notable beneficial effects on splanchnic, renal, respiratory and hemo-coagulative functions when intra-aortic balloon pump (IABP)-induced pulsatile perfusion has been employed in routine elective coronary surgery [5][6][7][8]. On the other hand, others did not observe any superiority of pulsatile perfusion with different devices over the traditional linear nonpulsatile CPB [9][10][11].…”

Einfluss von ECMO und IABP auf die Koronardurchblutung

“…Serraino et al [14] zeigten zudem im Jahr 2012, dass unter Verwendung eines pulsatilen kardiopulmonalen Bypasses die endotheliale Aktivierung und damit die Ausbildung einer postoperativen inflammatorischen Reaktion vermindert wurde. Die Kontroverse hinsichtlich pulsatil oder nichtpulsatil zeigt sich in Veröf-fentlichungen von anderen Arbeitsgruppen, die keinen signifikanten Unterschied zwischen beiden Perfusionsarten sehen [3,8,10].…”

Extracorporeal Circulation as a New Experimental Pathway for Myoblast Implantation in mdx Mice

“…The ischemia increases expression of paracrine mechanisms for mediating angiogenesis and regeneration of ischemic skeletal muscles (32). Moreover, the influence of different endothelial-derived vasoactive substances such as prostacyclin (15) liberated into damaged muscles results from an alter ation of endothelial structures. These events rapidly lead to invasion of the damaged sites by macrophages, granu locytes, and perfused myoblasts.…”