The cleavage plane in semi-closed endarterectomy of the superficial femoral artery: a histologic study.

PURPOSE

The purpose of this study was to determine the cleavage plane in semiclosed endarterectomy of the superficial femoral artery, a histologic study of endarterectomy cores of 10 consecutive patients was performed. Superficial femoral artery occlusive disease consisted of multiple stenoses in one and an occlusion in the other cases.

METHODS

Microscopic paraffin cross-sections were made every half centimeter of the endarterectomy core. The sections were stained with hematoxylin-eosin and with elastica van Gieson. Microscopic studies were conducted of a total of 484 sections. Intima, internal elastic membrane, media, external elastic membrane, and adventitia were identified, if present.

RESULTS

When the procedure of separating the diseased intima from the remainder of the arterial wall was commenced, the cleavage plane was located between the internal elastic membrane and the media in most cases. In two cases the cleavage plane was located inside the intima, and in one case parts of the media were removed as well. During passage of the ring stripper through the artery, the location of the cleavage plane changes and extends into the media. In one patient a residual stenosis was located in the segment of the core in which only the intima and internal elastic membrane were removed. In two patients the endarterectomy core contained parts of the external plastic membrane as well. During passage of the ring stripper through the artery, the location of the cleavage plane changes. In some segments the media is left intact, whereas in other segments the media is partially or totally removed. The reason for the variability of the cleavage plane rests in the nature of the pathologic behavior of the atheroma. The tissue necrosis that is part of the atheromatous complex frequently dips beyond the internal elastic membrane into the media and even into the external elastic membrane and adventitia.

CONCLUSIONS

The question remains as to whether the location of the cleavage plane has an influence on the long-term results of endarterectomy. Long-term follow-up studies are required to supply us with the answer.