A housing of an active medical device includes a metal wall having at least one feedthrough for an electrical connection through the wall. In the area of the feedthrough, the housing wall includes a contour groove extending through the thickness of wall, defining a metal islet electrically and physically isolated from the rest of the wall. The housing wall further includes an electrically insulating outer layer on the outer side of the wall extending over a region in alignment with the groove and beyond either side of the groove. The insulating outer layer includes a recess formed in alignment with the islet. The wall further includes an electrically conductive outer layer formed outside of the insulating layer and extending over the region in alignment with the groove and beyond either side of the groove. The islet is mechanically supported by the insulating and conductive outer layers.