Suboptimal luminal widening or acute closure secondary to arterial dissection remain significant risks of percutaneous transluminal balloon angioplasty. Non surgical techniques are often employed in an attempt to repair dissections either as temporary or definitive treatment. The aim of this study was to test the hypothesis that radiofrequency thermal balloon angioplasty at an operating temperature of 70 degrees C and low inflation pressure could seal dissections and perforations in a model of severe arterial wall damage. Dissections and perforations were created in renal (n = 4) and carotid (n = 4) arteries in four mongrel dogs. Endoluminal sealing was then attempted with conventional balloon angioplasty or radiofrequency thermal balloon angioplasty (2 atm at 70 degrees C). Contrast dye extravasation persisted in all cases following conventional balloon angioplasty but completely resolved with radiofrequency balloon angioplasty in all but one artery. Histologic examination of the arteries treated with radiofrequency balloon angioplasty showed extensive thermal injury, including transmural coagulation necrosis, flattening of the internal elastic lamina, and medial thinning. On the basis of these results, the utility of thermal balloon angioplasty for endoluminal sealing of dissections and perforations complicating angioplasty deserves further evaluation.