Urethral complications following ischiectomy in spinal cord injury patients: a urethral pressure study

Ischial ulcers are the most common pressure sores in spinal cord injury patients and ischiectomy often is used in the over-all management. Because a high percentage of spinal cord injury patients with total ischiectomy had complications of the membranous and proximal bulbous urethra, we evaluated urodynamically 15 ischiectomy patients in the supine and sitting positions to determine if pressure usually borne by the ischial tuberosities was transmitted to the membranous and proximal bulbous urethra. Of the 8 patients with a complete ischiectomy at least on 1 side 5 had problems of the membranous and proximal bulbous urethra, and the average urethral pressure increase from the reclining to the sitting position was 111 cm. water. The increase in urethral pressure was not related to any change in bladder or abdominal pressure. The average urethral pressure increase in the nonischiectomy patients was only 16 cm. water and none had any problems of the membranous and proximal bulbous urethra. Some retrospective clinical studies have implicated ischiectomy in the development of these urethral complications. Our urodynamic data lend some direct evidence that a more complete ischiectomy results in excessive urethral pressure with the patient in the sitting position, thereby predisposing the membranous and proximal bulbous urethra to problems related to ischemia. Five of the 8 patients with more complete ischiectomy and 1 with bilateral partial ischiectomy had high urethral pressures and complications, such as pseudodiverticulum, diverticulum and dilatation. More incomplete ischiectomy should be used to obviate this urethral damage.