The argon contact laser scalpel: a study of its effect on atherosclerosis

A new argon laser scalpel (ALS) that delivers radiation to tissue by direct contact was used to perform endarterectomies on atherosclerotic rabbit aortas in vivo. The resultant effects were compared to those induced by CO2 laser (CO2) and conventional surgical endarterectomy (END) to determine whether this instrument might be useful in the treatment of occlusive cerebrovascular disease. Light microscopy of the treated aortic segments revealed significantly more atheroma removed and less damage to the underlying media in the ALS segments compared to the CO2 segments. Electron microscopy showed that the ALS surface and distal intima-media interface were smoother and more even than those of the CO2 or END groups. Prostacyclin synthesis, as measured by 6-keto-prostaglandin F1a levels, was significantly reduced in the ALS compared to the END and control segments. These results indicate that the ALS is superior to CO2 in performing open laser endarterectomies, but such treatment places the atherosclerotic blood vessel at greater risk for thrombotic complications during the early postoperative period that does surgical endarterectomy. It is conceivable that a contact laser may be useful in the smooth welding of the distal edge of an atheroma (i.e., during carotid endarterectomy) and for the transcatheter ablation of surgically inaccessible obstructions of the cerebral circulation.