Use of the porous balloon in porcine coronary arteries: rationale for low pressure and volume delivery.

Abstract

Using agents administered systemically, attempts to control the restenotic myoproliferative response associated with angioplasty have been unsuccessful. The porous balloon has the advantage of achieving high local concentrations by directly infusing agents into the arterial wall. The purpose of this study is to identify any acute and chronic morphological changes in swine coronary arteries infused with normal saline through the porous balloon at different driving pressures. In order to establish the safety of local arterial wall infusion through the porous balloon, swine underwent porous balloon infusion of 3, 6, or 10 ml of saline at 5 atmospheres, or infusion of 3 ml of normal saline delivered at either 2, 5, or 10 atmospheres of pressure into the normal left anterior descending and left circumflex arteries. To assess the histopathologic alterations induced by the porous balloon, sized 1.1 to 1 with respect to the artery, animals were sacrificed either immediately after porous balloon infusion or 14 ays later. Acute vessels were evaluated for the presence of medial injury, disruption and/or dissection, whereas chronic vessels underwent morphometric analysis measuring the residual luminal area (Lumen area/Intimal area+Lumen area) and the maximal intimal thickness. Adequate adventitial penetration was confirmed by infusing as little as 2-3 ml of methylene blue at 2 atmospheres of pressure. Infusion of 3 ml of normal saline at 2 atmospheres resulted in minor focal medial edema and disorganization, detected both acutely and 14 days after porous balloon infusion. At delivery pressures of 5 or 10 atmospheres, proportionally more acute injury was noted and measurable neointimal lesions were observed 2 weeks after infusion.(ABSTRACT TRUNCATED AT 250 WORDS)