OBJECTIVE: A redo-cardiac surgical procedure in patients with a patent IMA graft is hazardous. Operative difficulties include: protection of the patent IMA graft, optimal cardioplegia delivery technique for myocardial protection, bleeding in the operative field and ability to control haemorrhage in the event of inadvertent injury to the IMA graft. We report our technique of using IMA-balloon occlusion at the time of redo-surgery. MATERIALS-METHOD: Cardiac surgical registry at our hospital was reviewed to identify consecutive series of patients with patent IMA-graft undergoing redo procedures between 1997-2003. RESULTS: Seven patients, all with previous CABG and patent IMA graft, mean age 72 years (range age 57-82 years) underwent redo-procedures. Mean time interval between the first and second operation was 8.7 years (range 1 to 14 years). Under general anaesthesia, the patients were taken to the catheter laboratory an angioplasty balloon was inserted in the IMA. Minimum volume necessary to occlude the IMA was ascertained. The balloon was then deflated prior to commencing surgery in a routine manner. The balloon was then only inflated to the pre-recorded level prior to cross-clamping the aorta. The operations performed included: aortic valve replacement (n=6) and aortic and mitral valve replacement (n=1). The IMA balloon is deflated prior to releasing the cross-clamp to re-perfuse the heart. All 7 procedures and post-operative course were entirely uneventful. CONCLUSION: IMA balloon occlusion technique as reported here potentially offers a much safer approach than many of the current practices and it overcomes many of the difficulties due to constant flow by the patent IMA graft.