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Restenosis following successful balloon valvuloplasty: bone formation in aortic valve leaflets
T Feldman1, S Glagov, J D Carroll
1University of Chicago Hospital, Cardiology Section, IL 60637.
Insights
Restenosis after balloon aortic valvuloplasty is common. Histologic analysis of restenosed valves reveals fibrosis and ossification, explaining limited success with repeat procedures.
Area of Science:
- Cardiovascular Medicine
- Interventional Cardiology
- Pathology
Background:
- Restenosis is a frequent complication following balloon aortic valvuloplasty, affecting up to 50% of patients within a year.
- Understanding the mechanisms of restenosis is crucial for improving treatment outcomes.
Purpose of the Study:
- To investigate the mechanisms of restenosis after balloon aortic valvuloplasty.
- To analyze the histological features of restenosed aortic valves.
- To evaluate the efficacy of repeat valvuloplasty procedures.
Main Methods:
- Analysis of outcomes from second balloon aortic valvuloplasty in 11 patients with calcific aortic stenosis.
- Histological examination of restenosed aortic valves excised from 5 patients during valve replacement surgery.
- Comparison of valve areas before and after first and second valvuloplasty procedures.
- Histological comparison with non-valvuloplasty control valves.
Main Results:
- First valvuloplasty significantly increased aortic valve area (0.63 to 1.09 cm2).
- Recurrence of stenosis led to valve areas similar to pre-procedure levels (0.56 cm2).
- Second valvuloplasty provided a smaller increase in valve area (0.76 cm2) compared to the first (0.45 vs 0.20 cm2 change).
- Histology revealed granulation tissue, fibrosis, and ossification in restenosed valves, distinct from initial calcific stenosis.
Conclusions:
- Histological changes in restenosed aortic valves include active proliferation, fibrosis, and ossification.
- These pathological changes differ from initial calcific aortic stenosis.
- The observed histological features may explain the diminished effectiveness of repeat balloon aortic valvuloplasty for restenosis.
Abstract:
Restenosis after balloon aortic valvuloplasty is common, occurring in as many as half or more of patients in the first year. To gain understanding of the mechanisms of restenosis we examined results of second dilatations and the histology of restenosed valves excised during valve replacement for restenosis. Eleven patients with calcific aortic stenosis underwent second valvuloplasty for restenosis. The mean age was 82 +/- 6 years. The interval between first and second dilatation was 14.7 +/- 8.5 months. First valvuloplasty resulted in an increase in valve area from 0.63 +/- 0.23 to 1.09 +/- 0.32 cm2 (p < 0.01). The valve area found after symptoms recurred was 0.56 +/- 0.18 cm2, not significantly different from the prevalvuloplasty dimensions. Second dilatation resulted in a mean aortic valve area of .76 +/- 0.22 cm2 (p = 0.011 vs results of first valvuloplasty). The change in valve area after first dilatation was 0.45 +/- 0.17 vs 0.20 +/- 0.13 cm2 after second dilatation (p < 0.01). Multiple histologic sections from excised, restenosed valves from five additional patients showed zones of active capillary and cellular proliferation and fibrosis in crevices between calcific nodules in three cases. Associated foci of ossification were seen in two of these. Stenotic nonvalvuloplasty control valves (n = 19) showed no ossifications. In conclusion, histologic changes in restenosed valves differ from those seen initially in calcific aortic stenosis, with granulation tissue, fibrosis, and ossification being present. These findings may help to explain the limited results of second dilatations for restenosis.