To assess the risk of late side branch occlusion after Palmaz-Schatz s
tent deployment, we analyzed the angiographic evolution of 62 patients
treated by successful stent implantation who had a total of 85 side b
ranches starting from the stented segment. Side branches were consider
ed minor (n = 39) when the diameter was <1 mm and intermediate (n = 46
) when the vessel had greater than or equal to 1 mm diameter. One angi
ographic follow-up study was available in all patients at 8 +/- 5 mont
hs. Eight minor branches presented some degree of stenosis at origin b
efore stent deployment (4 totally occluded). After stent deployment, 3
2 (82%) of 39 remained unchanged and 3 became occluded. Late progressi
on at origin occurred in 4 of 34 (3 occluded). Before stent deployment
, 48% of the intermediate branches had some compromise degree at their
starting point (1 totally occluded). Eight of 45 intermediate branche
s became occluded after stent implantation. Late progression at origin
happened in 5 of 32 branches (2 occluded). Some degree of follow-up s
tenosis regression at the origin was observed in 22 (26%) of 85 arteri
es. Neither clinical nor angiographic factors could be identified as p
redictors of late side branch occlusion or stenosis progression at its
origin. Later occlusion or progression at origin of a side branch cov
ered by a Palmaz-Schatz stent seems to be an uncommon occurrence (7% a
nd 12% respectively) that cannot be predicted by angiographic or clini
cal factors. On the contrary, regression at follow-up of a side branch
-origin stenosis can also come about.