Fehmi Keçe

Chapter 2 46 2.5 Hotballoon 2.5.1 Historical overview The hotballoon (HotBalloon catheter, Sataka, Toray Industries, Tokyo, Japan) is a compliant RF-based balloon (25-35 mm) which is filled with saline and contrast. The balloon can be heated to a temperature of 65-75 °C through a coil electrode inside the balloon. Energy delivery is based on thermal conduction to the tissue in contact with the balloon surface. The first human study has shown that 2-3 applications of 2-3 minutes duration were required to achieve PVI resulting in AF free survival of 92% off AAD during a mean follow- up of 11±5 months (104). In consecutive studies, reported outcome off AAD was 78, 59 and 65% after 1, 6.3 and 3.6 years, respectively (105-107). Randomized studies comparing the hotballoon with other ablation technologies are lacking. 2.5.2 Complications In an early animal study published in 2001, no major complications were reported (108). In a human feasibility study, oesophageal injury, however, occurred in 3 of the first 6 cases. After introduction of oesophageal cooling with saline, consisting of repeated injections of 10-20 ml mixture of contrast medium and saline, cooled at 10˚C during applications, only one additional injury was observed in the next 58 patients (109). In a series of 502 patients, the incidence of oesophageal injury could be further reduced by adapting the oesophageal temperature cut-off (39° C instead of 41° C) (107). Additional procedural related complications included PNP and PVS. In a series of 319 ablations performed in 238 patients, 16 major complications occurred: >70% PV stenosis in 4 (1.7%), temporary PNP in 8 (3.4%) and oesophageal injury in 4 (1.7%) (105). In a randomized controlled trial comparing hotballoon with AADs, for paroxysmal AF major complications were reported in 15 (11%) patients: PV stenosis of >70% in 5% and transient PNP in 3.7% (106). The hotballoon is still under investigation and optimal ablation energy and duration needs to be determined.