Residual Stenosis Poststenting and Subsequent Decrease in the Proximal Reference Diameter Are Correlated:Excessive Axial Wall Stress Is a Plausible Explanation

Abstract

Purpose: To test the hypothesis that edge restenosis in stented lesions might be due to an increase in axial wall stress in the adjacent proximal vessel segment by examining whether the proximal reference diameters of conventionally stented lesions are reduced at follow-up and whether this reduction depends on the degree of residual stenosis poststenting. Methods: The literature published in the past 5 years dealing with restenosis following implantation of standard stents was screened for the availability of (1) reference vessel diameters poststenting, (2) mean residual stenosis poststenting, and (3) mean reference vessel diameters at follow-up in the same patients or groups of patients. Data collected from 11 publications were pooled and used to compute the change in reference segment diameter over time. These differences were compared to the residual stenosis poststenting by nonlinear regression. Results: The reduction in the mean reference diameters over time and the mean residual stenosis poststenting appear to be strongly correlated (r ²=0.838), which supports the idea that the evolution of a stenosis adjacent to a stent margin depends on the severity of the residual stenosis. Conclusions: This finding indicates that edge restenosis might be due to excessive axial wall stress. It may also explain, at least partly, why edge restenosis is observed with catheter-based brachytherapy and radioactive or drug-eluting stents.