[Endothelial lesions caused by intra-aortic counterpulsation balloons]

Comparison between 3 Aortic Clamps for Video-Assisted Cardiac Surgery: A Histological Study in a Pig Model

OBJECTIVES

To assess histological traumatic effects of aortic clamps used in video-assisted surgery, an experimental study was undertaken in a pig model, comparing the Portaclamp, Endoclamp, and a metallic clamp.

MATERIAL AND METHODS

In 3 groups of 5 pigs each, the descending aorta was exposed through a posterolateral left thoracotomy. External clamps (Portaclamp and metallic clamp) were positioned at the middle of the aorta. Endoclamps were inserted at the top of the descending aorta through a small purse and inflated lower. After 60 minutes of clamping, the clamp was removed and the animal reperfused for 60 minutes. It was then sacrificed and the descending aorta was harvested for blind histological study using hemotoxylin-eosin staining of 4 samples per animal: A, before the clamping spot; B, at the clamping spot; C, after the clamping spot; D, a remote sample as control.

RESULTS

In the Portaclamp and metallic clamp groups, there were no lesions of the intima in all aortic samples. In the Endoclamp group, severe lesions of the intima were observed on the clamping spot: endothelium crushing with flattening of cell nucleus (3/5) or endothelium stripping with vanishing of cell nucleus all gathered in 1 point (2/5). Only spongy lesions (clearance between fibers) located on the external third of the media and moderate inflammatory lesions of the adventice were observed with a random distribution in aortic samples without difference between groups.

CONCLUSIONS

This study reveals the impressive lesions of the aortic intima due to the Endoclamp. The nonspecific lesions observed in media or adventice may be related to the surgical trauma of the procedure.

Effect of intra-aortic occlusion balloon in external thoracic compressions during CPR in pigs

This study was performed to compare the effectiveness of external thoracic compressions with and without intra-aortic occlusion balloon with capnography and coronary and cerebral perfusion pressure (CPP) in the normothermic and traumatic-less cardiopulmonary arrest provoked by a ventricular fibrillation in pigs. This was an experimental study (cross-over study) in 14 pigs with similar characteristics (23 +/- 2 kg, 10-12 weeks of age). After an 8-minute nonintervention period, the cardiopulmonary resuscitation (CPR) consists of 4 periods of 5 minutes alternating CPR with and without intra-aortic occlusion balloon. Main outcomes measured are end-tidal CO(2) (ETCO(2)); intra-aortic, coronary, and cerebral perfusion pressures; blood gas analysis; and blood lactate concentration. At the end of each period, levels are obtained. Postmortem study was made. Inflation of the occlusion balloon provokes an expansion in the ETCO(2) of about 38%. The coronary perfusion pressure initially goes from 10.21 to 29.0 mm Hg after the occlusion of the aorta, which means an increase of 150%. The CPP goes from 12.54 to 39.71 mm Hg after the balloon was inflated, which means an increase of 200%. In all cases the differences are statistically significant (P <.0001). These increases are less important in the final periods. Intra-aortic balloon occlusion increased ETCO(2), coronary, and cerebral perfusion pressures. An early application of this technique was important.