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Updated: Sep 20, 2026
A Recovery Cardiopulmonary Bypass Model Without Transfusion or Inotropic Agents in Rats
Published on: March 23, 2018
Avoidance of full-sternotomy: effect on inflammatory cytokine production during cardiopulmonary bypass in rats
Yoshitaka Hayashi1, Yoshiki Sawa, Motonobu Nishimura
1Department of Surgery, Course of Interventional Medicine (E1), Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka 565-0871, Japan.
Background And Aim Of The Study:
Although open heart operations via a mini-sternotomy or mini-thoracotomy are considered "less invasive" cosmetically and are hopeful for early social recovery, clinical experiences have not shown less invasiveness toward systemic inflammatory response, because of the wide variety of patients and operative procedures encountered. We examined the effect of a mini-sternotomy on an inflammatory response during a cardiopulmonary bypass (CPB) procedure performed in rats.
Methods:
Thirty-two adult Sprague-Dawley (SD) rats, each of which underwent a 120-minute CPB, were randomly divided into four groups according to the method of exposing the pericardial cavity; no sternotomy (Group N [0 cm], n = 8), right para-sternal thoracotomy (Group P [2 cm], n = 8), lower mini-sternotomy (Group M [2 cm], n = 8), and full-sternotomy (Group F [4 cm], n = 8). Blood samples were obtained (1) just prior to the initiation of CPB, and then (2) 30, (3) 60, and (4) 120 minutes after the initiation of CPB.
Results:
Thirty minutes after the initiation of CPB, there were significant differences in plasma interleukin [IL]-6 levels between groups, except for Groups P and M; whereas at 60 minutes the only significant difference occurred between Groups N and F, and at 120 minutes there were no significant differences between any of the groups. Further, plasma IL-8 levels were not significantly different at each sampling point between all of the groups.
Conclusions:
These results first demonstrate experimentally that the avoidance of a full-sternotomy can be considered a less invasive strategy in terms of reducing the systemic inflammatory response that accompanies a shorter CPB duration.
Insights
Avoiding a full sternotomy reduces the inflammatory response during cardiopulmonary bypass (CPB). This study in rats suggests mini-sternotomy is a less invasive surgical strategy for CPB procedures.
Area of Science:
- Cardiovascular Surgery
- Surgical Innovation
- Inflammatory Response
Background:
- Minimally invasive cardiac surgeries aim for cosmetic and social recovery benefits.
- Clinical outcomes have not consistently shown reduced systemic inflammatory response with less invasive approaches.
- Investigating the inflammatory impact of sternotomy methods during cardiopulmonary bypass (CPB) is crucial.
Purpose of the Study:
- To experimentally evaluate the effect of mini-sternotomy versus full-sternotomy on systemic inflammatory response during CPB in a rat model.
- To compare inflammatory markers across different sternotomy techniques and a control group.
Main Methods:
- Thirty-two rats underwent 120-minute CPB and were randomized into four groups: no sternotomy, right parasternal thoracotomy, lower mini-sternotomy, and full sternotomy.
- Blood samples were collected pre-CPB and at 30, 60, and 120 minutes post-CPB initiation.
- Plasma levels of Interleukin-6 (IL-6) and Interleukin-8 (IL-8) were analyzed.
Main Results:
- Significant differences in plasma IL-6 levels were observed at 30 minutes post-CPB between groups, excluding P and M.
- At 60 minutes, only the no sternotomy (N) and full sternotomy (F) groups showed significant IL-6 differences.
- No significant differences in IL-6 or IL-8 levels were found between any groups at 120 minutes.
Conclusions:
- The avoidance of a full sternotomy is an experimentally validated less invasive strategy.
- Reducing sternotomy extent can mitigate the systemic inflammatory response associated with CPB.
- Shorter CPB duration may be linked to reduced inflammation when avoiding full sternotomy.
