Avoidance of full-sternotomy: effect on inflammatory cytokine production during cardiopulmonary bypass in rats.
OBJECTIVE
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.
Hayashi
Yoshitaka
Y
Department of Surgery, Course of Interventional Medicine (E1), Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka 565-0871, Japan.
Sawa
Yoshiki
Y
Nishimura
Motonobu
M
Satoh
Hisashi
H
Ohtake
Shigeaki
S
Matsuda
Hikaru
H
D000818:Animals; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D016207:Cytokines / Q000096:biosynthesis; D007249:Inflammation / Q000209:etiology* / Q000378:metabolism*; D015850:Interleukin-6 / Q000097:blood*; D016209:Interleukin-8 / Q000097:blood*; D008297:Male; D019060:Minimally Invasive Surgical Procedures / Q000379:methods*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013249:Sternum / Q000601:surgery*
D016207:Cytokines; D015850:Interleukin-6; D016209:Interleukin-8