POROUS BALLOON DELIVERY OF LOW-MOLECULAR-WEIGHT HEPARIN IN THE DOG CORONARY-ARTERY

The aim of this experimental study was to assess the safety of local d elivery of low molecular weight heparin via a porous balloon in the ca nine coronary artery. In 16 mongrel dogs, percutaneous transluminal co ronary angioplasty was performed. In addition, eight of the dogs were given 4 mi Clivarin (1500 IU) delivered locally into the coronary arte ry immediately after dilatation. The animals were killed after 3 or 14 days. In the animals with local administration, the results of histop athology after 3 days showed the findings to be heterogeneous with mar ked disruption of the internal elastic lamina in all animals, and vary ing degrees of medial haemorrhage, medial necrosis, perivascular haemo rrhage and signs of myocardial necrosis. Similar changes, but of lesse r severity, were present in the animals treated with balloon dilatatio n only, After 14 days, the severity of vascular and perivascular alter ations (medial haemorrhage, perivascular haemorrhage, thrombus formati on) was significantly lower in the local delivery group (P<0 . 05). bu t disruption of the internal elastic lamina, as a marker of the initia l trauma, was present in all the animals. The presence of residual int racoronary thrombus was only seen in the PTCA group without local deli very. Conclusions In this safety study, both groups showed pronounced alterations in the vessel wall 3 days following percutaneous translumi nal coronary angioplasty. This changed 14 days following percutaneous transluminal coronary angioplasty when intramural injection of Clivari n resulted in a marked decrease of residual thrombus and medial as wel l as perivascular haemorrhage. Although the additional vessel trauma b y the drug delivery technique did not result in increased complication s, a careful approach with this potentially harmful procedure is essen tial.