[Effect of high insufflation pressures on elastic recoil forces and vascular resistance after balloon dilatation]

In this study, we examined whether percutaneous coronary angioplasty (PTCA) of native coronary arteries with high inflation pressure can improve the immediate postinterventional result in comparison to PTCA with nominal inflation pressure. Using quantitative coronary angiography, we analyzed the coronary angiograms of 24 patients who underwent PTCA with nominal inflation pressure (< 10 atm; group 1) and of 20 patients who underwent PTCA with high inflation pressure (> or = 10 atm; group 2). Only balloon catheters with little compliance were used. The following variables were recorded: 1) minimal luminal diameter (MLD), reference diameter and percent diameter stenosis before and after PTCA, 2) average balloon diameter during PTCA, 3) balloon/artery diameter ratio, 4) acute luminal gain (difference between MLD before and after PTCA), 5) nominal elastic recoil (difference between nominal balloon diameter and MLD after PTCA), 6) actual elastic recoil (difference between average balloon diameter during PTCA and MLD after PTCA). Nominal balloon diameter, reference diameter before and after PTCA and the balloon/artery diameter ratio were similar in both groups. Application of high inflation pressure resulted in a greater average balloon diameter. In group 2 (high inflation pressure), average balloon diameter amounted to 94 +/- 12% of nominal balloon diameter, whereas in group 1 (nominal inflation pressure), it reached only 84 +/- 9% of nominal balloon diameter. Actual elastic recoil was not different between the two groups. Nominal elastic recoil, however, was greater in the cohort which received PTCA with nominal inflation pressure (1.13 +/- 0.35 mm vs. 0.83 +/- 0.28 mm; p < 0.02). After use of high inflation pressure, acute postinterventional luminal gain was significantly increased (1.04 +/- 0.25 mm vs. 0.77 +/- 0.34 mm; p < 0.02) and the postinterventional percent diameter stenosis was significantly lower (12 +/- 10% vs. 24 +/- 13%; p < 0.05). Application of high inflation pressure improves the postinterventional result after PTCA because of a greater acute luminal gain. The stenotic coronary artery is expanded to a greater degree, and actual elastic recoil remains unchanged.