The winding path to sacral foramen neural modulation: a historic chronology

In the decade of the 1970's, the NIH was captivated by the dream of harnessing electrical stimulation for widespread therapeutic goals. After the success of pacemakers in the 1960's hopes were high that a number of compromised body functions could be helped. These included hearing loss, seizure disorders, scoliosis, pain control, and in spinal cord injury patients: the restoration of lost limb function, walking and breathing, and bladder control. It was a comprehensive program involving numerous research centers and included a wide variety of talent, from chemical and electrical engineers to PhDs and MDs from a variety of disciplines. The University of California in San Francisco was invited to be part of the program, largely because of its leadership status in the field of urodynamics at the time. Research was carried out throughout the decade in the successful attempt to make neural stimulation an everyday therapy for compromised bladder function. The program was carried out in phases. Initial efforts were directed at direct stimulation of the bladder wall, then the spinal cord directly, and finally the sacral roots. The goal was to achieve synergic voiding. While that didn't happen, intermittent voiding was achieved and a whole new meaning to the term modulation therapy opened up. The following paper discusses the research path into the development of sacral nerve stimulation from the lab through clinical trials to FDA approval. Critical observations linking the human situation to the lab experimental observations are underscored. The pitfalls in transition from the university environment to commercial application are depicted, along with all the human roadblocks that arose. It was a 25-year program that influenced the careers of many "fellows" worldwide. It culminated in successful patient therapy because of the generous collaborative efforts of many academic centers in Europe and North America. It was an era where all the necessary elements were in place-the NIH leadership, the combination of research talent and lab animal availability, adequate funding, and a high level of subject interest. The research environment prior to and after this time period was not nearly as friendly, either politically nor fiscally, to this sort of research program. Had it not been for this mix of forces the therapy may never have evolved.