Though these hybrid techniques are under active investigation, the published literature is limited to a few early feasibility studies. Early investigators used a unilateral right thoracoscopic approach to isolate the PVs with a single encircling box lesion. The energy source for the surgical ablation was monopolar RF (Cobra Adhere, Estech, San Ramon, CA). Nineteen consecutive patients underwent a right unilateral minimally invasive hybrid procedure. Ten patients (52.6%) had long-standing persistent AF, whereas four (21.1%) had persistent and five (26.3%) PAF.1375 In 17 patients, one or more PVs (mostly the LSPV) were not isolated, and an endocardial touch-up was needed. It was possible to complete all the procedures as planned, without any conversion to cardio-pulmonary bypass. No patient died during the follow-up. At 1 year, 7 of 19 (36.8%) patients were in sinus rhythm with no episode of AF and off AADs. Among the patients with longstanding persistent AF, 20% (2 of 10) were in sinus rhythm and off AAD, 50% (2 of 4) in persistent and 60% (3 of 5) in PAF. Disappointing 1-year results were attributed to an inadequate energy source. Thus, the surgical portion of the procedure was converted to use a bipolar RF clamp (AtriCure Inc., West Chester, OH), which had been shown to be more effective.1376 This approach provided improved results, and in most cases, gaps in surgical lesions could be completed by endocardial catheter ablation during the same procedure.608 A sequential hybrid approach was subsequently developed.606 There are advantages and disadvantages to simultaneous and staged hybrid procedures.