Serial changes in the three-dimensional aspect of the side-branch ostium jailed by a drug-eluting stent assessed by optical coherence tomography

The present study investigated serial changes in the three-dimensional (3D) aspect of the jailed side-branch (SB) ostium. We evaluated 32 patients who underwent examination with optical coherence tomography (OCT) both at baseline and at follow-up. After reconstruction of the 3D images, we classified the configuration of overhanging struts at the SB orifice into three groups according to the 3D aspect of the jailing configuration. The number of compartments divided by the stent strut was counted. The side-branch flow area (SBFA), i.e., the area of the SB ostium except for jailing struts, was measured by cut-plane analysis. Forty-eight SBs of 25 patients were analyzed. Thirteen SBs were classified as the No-jail type (N-type), 19 as the Simple-jail type (S-type; no longitudinal link at the carina), and 16 as the Complex-jail type (C-type; had a link at the carina). In the N-type, the SBFA was significantly increased at follow-up (P = 0.018). In the C-type, the SBFA was significantly decreased at follow-up (P = 0.002). Percent reduction of SBFA in the C-type group was significantly greater than that in the N-type or S-type groups (S-type vs. C-type P = 0.002, N-type vs. C-type P < 0.001). 3D-OCT images showed that some of the compartments were filled with tissue. The number of compartments was significantly decreased at follow-up (P < 0.001). In the C-type group, the SBFA was significantly decreased and small compartments were filled with tissue. These findings suggest that stent jail complexity is associated with the progression of SB ostial stenosis.