RADIOFREQUENCY THERMAL ANGIOPLASTY MAINTAINS ARTERIAL DUCT PATENCY - AN EXPERIMENTAL-STUDY

Background Long-term maintenance of arterial duct patency by a cathete r technique would be a valuable nonsurgical method of palliation for d uct-dependent circulations. We used a new method: percutaneous radiofr equency thermal balloon angioplasty of neonatal lamb arterial ducts. M ethods and Results Radiofrequency balloons 5 or 6 mm in diameter were introduced via the femoral vein of 32 neonatal lambs and inflated to 4 atm. In 28, a radiofrequency generator was used to heat the saline/co ntrast mixture in the balloon to 65 degrees C (n=2), 75 degrees C (n=2 ), 85 degrees C (n=10), 100 degrees C (n=8), and 120 degrees C (n=6). In 4 lambs, angioplasty alone was performed. Lambs were recatheterized to assess patency at intervals up to 78 weeks. Immediate results show ed the arterial duct to be patent in all cases, with a mean rise in sy stolic pulmonary artery pressure of 13+/-8 mm Hg and a mean rise in pu lmonary artery oxygen saturation of 12+/-15%. With a mean follow-up of 45.7+/-28 weeks, 3 of the 4 (75%) angioplasty alone ducts closed, but only 5 of the 28 (18%) radiofrequency-treated ducts (P<.05). The mean rise in oxygen saturation between the superior vena cava and the pulm onary artery was 7.6+/-7% at last follow-up. Follow-up angiography of the arterial ducts showed the development of stenoses in all patent du cts. Conclusions Radiofrequency thermal balloon angioplasty leads to l ong-term arterial duct patency in lambs in >80% of the treated group a nd is significantly more effective than balloon angioplasty alone.