P 648. The Influence of Secondary Untethering on Bladder Function of Spina Bifida Patients
30 October 2018 (online)
Background: Spina bifida is a neural tube malformation associated with various comorbidities. After primary neurosurgical treatment, many patients develop a secondary tethered cord, which can lead to aggravation of bladder dysfunction and/or motoric function. One tries to achieve an improvement by a secondary operative adhesiolysis of the spinal cord (untethering). Data on the effect of secondary untethering on the bladder dysfunction are based on small cohorts and are divergent. Moreover, different indications for the untethering have not been considered.
Aim: The aim of this work is to describe the effects of untethering on bladder function.
Question: Are there correlations between surgical indication and change of bladder function after untethering?
Methods: A retrospective study was performed on a cohort of 306 patients with spina bifida. All patients were cared for at the Social Pediatric Center, Department of Neuropediatrics, Charité. On 130 patients, a total of 182 neurosurgical treatments were performed. We included patients who received an urodynamic examination within 12 months before and after the procedure. In addition to the indication for untethering, the urodynamic parameters such as bladder capacity, detrusor pressure, leak point pressure, and compliance were recorded. The severity of bladder dysfunction was divided (1) into stages, based on the classification of Abrahamsson, Kate et al. 2007 and (2) by use of a modified hostility score (AWMF guideline). Stage 1 corresponds to low detrusor pressure (<20 mmH2O), stage 2 to medium detrusor pressure (20–60 mmH2O), and stage 3 to high pressure (> 60 mmH2O). Within the modified score, points from 0 to 2 are awarded for the condition of the bladder capacity, maximal pressure during autonomic contraction, and leak point pressure, respectively, with a high score indicating a poor bladder condition.
Results: In this study, 56 patients met the inclusion criteria (n = 50 spina bifida aperta, n = 6 spina bifida occulta). The mean age at the time of surgery was 8.9 years (range: 0.5–22.5). The indications for the surgery were in 16% (n = 9) worsening of bladder function, in 37% (n = 21) motoric impairment, in 30% (n = 17) worsening of bladder and motoric function, and in 16% (n = 9) preparation of spinal fusion. Overall, the clinical situation improved by the stages scheme in 2 out of 56 patients, and after modified hostility score in 8 out of 56 patients. Looking at the stages scheme before and after the surgery, the number of patients improving and worsening is equal (each n = 11, 20%), 60% (n = 34) remain unchanged. In contrast the hostility score improves in 46% (n = 26), worsens in 30% (n = 17), and remains unchanged in 23% (n = 13). Most patients with postoperative worsening of bladder function compared with preoperative findings (67% at staging, 60% at modified hostility score) underwent surgery because of the worsening of motoric function as indication.
Conclusion: No correlation could be found between bladder improvement and surgical indication. Patients who were operated solely due to the deterioration of motoric functions more often show a postoperative worsening of bladder function compared with other indications.