**4. Mapping guided laser photocoagulation**

The search for different treatment options finally led to the introduction of laser energy into this type of cardiac surgery (13,14,15,16,17,18,19). Using a conventional Nd-Yag laser and a gas cooled fiber for energy transmission, deep photocoagulations of the diseased tissue can be performed. Tissue is not removed or ablated in the original sense, but the structural integrity of the lased area remains intact. This deep photocoagulation creates a homogenious kind of scar and stops the reentry circuit. This kind of treatment is not limited to the endocardium but can also be applied to the epicardial surface after an electrophysiological mapping.

Consequently, mapping was no longer limited to the endocardium after resection of an aneurysm, but was extended to the epicardial surface during the same procedure (18). By this combination, recurrencies could be significantly reduced.

Moreover, in cases of only small scar areas and without an aneurysm as access to the left ventri‐ cle, our group, together with the pioneering group of Svenson and Selle, performed the first cas‐ es of sole epicardial ablation, so to avoid a ventricular incision and further myocardial damage (20). Even with deep laser lesions, this limited access can of course not reach certain regions of the myocardium, especially the septum and the papillary muscles but we could still eliminate signif‐ icant numbers of VT´s in this special cohort of patients and avoid the implantation of an ICD.
