RESUMO
The aim of this study was to assess the frequency and severity of dissection during repeat angioplasty for restenosis, to correlate the occurrence of this event with the lesion characteristics and the procedure-related factors and to examine if dissection during initial angioplasty predisposes to dissection during the repeat procedure. Sixty-nine significant lesions in native coronary arteries were treated with balloon angioplasty (A«PTCA) and retreated for restenosis with balloon angioplasty (B«PTCA). Dissection was detected less frequently during B«PTCA (7/69 vs. 18/69, p < 0.05). Anatomic variables did not differ significantly between A« and B«PTCA. Balloon to artery ratio (B/A ratio) was slightly but significantly higher during B«PTCA (1.03 +/- 0.13 vs. 0.97 +/- 0.14, p < 0.05) and duration of inflation was shorter (377 +/- 218 vs. 473 +/- 305 sec, p < 0.05). In 17 out of the 18 lesions which were dissected during A«PTCA, dissection did not occur during B«PTCA, despite the application of a higher B/A ratio (1.05 +/- 0.13 vs. 0.97 +/- 0.17, p < 0.05). Duration of inflation was shorter during B«PTCA (390 +/- 227 vs. 639 +/- 394 sec, p < 0.05). Six out of seven lesions which were dissected during B«PTCA had not been dissected during A«PTCA. In this subgroup, lesion characteristics did not differ between the two interventions and duration of inflation was shorter during B«PTCA (340 +/- 101 vs. 458 +/- 128, p < 0.05). CONCLUSIONS: Dissection occurred less frequently during restenotic lesion PTCA. Dissection during A«PTCA did not predispose to dissection during B«PTCA. These findings may be ascribed to the proliferative nature of the restenotic process.
