The Tethered Cord Syndrome: Urodynamic Evidence of Improved Outcome With Early Untethering

Andrew S. Youkilis, MD
Hong Jin Suh, MD
Harry Koo, MD
David A. Bloom, MD
Karin Muraszko, MD (Ann Arbor, MI)

Urologic dysfunction is a common presenting symptom in patients with the Tethered Cord Syndrome(TCS). In order to test the hypothesis that early untethering can prevent the development of urologic symptomatology, we retrospectively reviewed the pre and postoperative urodynamic records of 82 children with TCS who underwent spinal cord untethering at the University of Michigan from February 1990 to March 1999. Each patient was evaluated with pre and postoperative cystometrogram(CMG), voiding cystourethrogram(VCUG) and serial renal ultrasound(U/5). Of 50 patients evaluated to date, 21 patients presented with primary spinal cord tethering(Group 1). The other 29 patients presented with secondary tethering following previous myelomeningocoele repair(Group 11). In both groups, patient; were predominantly pediatric with only 6 patients older than age eight.

In Group I the majority of patients presented with flat preoperative CMG, absence of reflux on VCUG and no evidence of hydronephrosis on U/S. Postoperative urodynamics revealed stable filling pressures without progression on serial CMG and mean follow–up of greater than one year. Two patients with detrusor hyperreflexia had resolution on postoperative CMG. Patients in Group 11 all had significant preoperative urodynamic abnormalities including low compliance, detrusor hyperreflexia and areflexia. There was no statistically significant improvement/worsening on postoperative studies. This study provides further evidence that early untethering in patients with TCS is safe and effective at preventing urodynamic worsening. It clarifies that our ability to prevent urologic symptomatology continues to be better than our ability to reverse urologic abnormalities once already present.