 The surgical technique differ somewhat with respect to which layer of the abdominal is being used 8, when using a bi-layer- or a single sheet mesh. With the bi-layer mesh you use the abdominal layer that is usually used the pre-peritoneal space in case of re-operation due to recurrence after open mesh repair. Re-operation after bi-layer mesh IHR is incompletely studied and it is unclear if this is a more difficult surgical procedure compared with re-operation for recurrence after standard IHR. 