FRAGMENTATION OF INTERNAL ELASTIC LAMINA AND SPREAD OF SMOOTH-MUSCLE CELL-PROLIFERATION INDUCED BY PERCUTANEOUS TRANSLUMINAL CORONARY ANGIOPLASTY

We investigated smooth muscle cell proliferation associated with reste nosis after percutaneous transluminal coronary angioplasty (PTCA) in 8 arteries with fragmented internal elastic lamina obtained at autopsy in 7 patients who died between 2 months to 2 years 11 months after cor onary angioplasty. The internal elastic lamina fragmentation, measured longitudinally along the blood vessels, measured 6.6 +/- 6.9mm. Smoot h muscle cell proliferation was concentrated around the fragmented int ernal elastic lamina, extending longitudinally even to unfragmented ar eas. The proliferation of smooth muscle cells extended for 1.8 +/- 2.2 mm in the proximal portion of the fragmentation, and for 2.0 +/- 2.9 mm in the distal portion. The possibility of new stenoses resulting fr om smooth muscle cell proliferation at sites adjacent to those subject ed to PTCA should be borne in mind when PTCA of the proximal segments of the left anterior descending coronary artery is contemplated.