title: Spina bifida occulta as a relative contraindication for percutaneous retrograde lead insertion for sacral nerve root stimulation.
abstract: Percutaneous retrograde lead insertion for sacral nerve root stimulation is a newly described technique being applied to a variety of pain disorders. The success of the procedure rests in a defined epidural space such that there is unimpeded progression of the lead into the desired location. It is hypothesized that any condition that results in anatomic compromise of the epidural space would prevent the success of the procedure. Two patients with biopsy-proven interstitial cystitis and intractable pain were referred to the senior author for evaluation. Percutaneous retrograde lead insertion for sacral nerve root stimulation was performed on these patients in a standard fashion (1,2). Intraoperative fluoroscopy verified the diagnosis of spina bifida occulta. In one patient, implantation was completed percutaneously, but later two of the leads were found to have been placed intradurally. In another patient, repeated attempts at passing the epidural lead distal to the congenital defect were unsuccessful, and the percutaneous procedure was aborted. In conclusion, we have found that the diagnosis of spina bifida occulta, or any other condition in which the epidural space is anatomically disrupted, is a relative contraindication for this procedure. Preoperative roentograms of the lumbar spine may be helpful in avoiding technical difficulties due to this diagnosis.
authors.affiliation: The University of Tennessee at Memphis Department of Neurosurgery,              Semmes-Murphey Clinic, and              Methodist Hospital Comprehensive Pain Clinic, Memphis, Tennessee.
authors.forename: L Madison
authors.initials: LM
authors.lastname: Michael
authors.forename: Louis A
authors.initials: LA
authors.lastname: Whitworth
authors.forename: Claudio A
authors.initials: CA
authors.lastname: Feler