A balloon occlusion technique to overcome the convective warming effect of coronary sinus blood flow on cryoablation

Introduction Since its first human application in 1998, transcatheter cryoablation has emerged as a viable alternative to radiofrequency ablation. Its enhanced safety profile, including an obligatory phase of reversible tissue inhibition prior to permanent cellular damage, has rendered cryoablation an attractive treatment option for perinodal and peri-Hissian substrates. Several factors may influence the creation of effective and durable cryoablation lesions, including electrode-tip size, cooling rate, nadir temperature, electrode-tip-to-tissue contact pressure and orientation, duration of freezing, number of freeze–thaw cycles, and convective warming by local blood flow. Under certain circumstances, the warming effect of high blood flow rates may have desirable consequences. For example, blood flow within adjacent vascular structures, such as coronary arteries, affords natural protection against inadvertent corollary damage. However, convective warming of the catheter tip and targeted tissue has a detrimental effect on lesion formation.