Video-urodynamic Profile in Postoperative Cases of Lumbosacral Myelomeningocele with Neurogenic Bladder

Neurogenic bladder is a very common sequel in cases of spina bifida with variable prevalence ranging between 46% and 80%. Conventionally, these patients are analyzed using urodynamic studies (UDSs), with some chances to be misinterpreted, as a large percentage of these subjects are associated with vesicoureteric reflux (VUR), for which video-UDS (VUDS) is considered to be investigation of choice.

The study included 24 postoperative patients (at least 3 months postoperative) of lumbosacral myelomeningocele with urinary complaints over a 1-year period. The VUDS parameters and presence of VUR were noted along with sonographic evaluation of the urinary tract as well as renal function tests. VUDS was done using the HERMES model, and micturating cystourethrography films were taken using the C-arm fluoroscopy machine. Postvoid residual urine (PVRU) was calculated using a portable ultrasonography (USG) scanner. Based on the VUDS parameters, we tried to categorize the type of neurogenic bladder and also establish a correlation between the VUDS profile and upper tract changes if any.

There were 20 males and 4 females, age range of 9 months to 11 years. On USG kidney ureter bladder, there were mild bilateral hydronephrosis (n = 1), moderate to gross bilateral hydroureteronephrosis (n = 2), and thickened bladder (n = 7). On VUDS, high detrusor pressures were noted in 58% of cases (n = 14) and high sphincter pressures in 20% (n = 5) of patients. Detrusor sphincter dyssynergia (DSD) was present in 50% of cases (n = 12). PVRU was significant in 87.5% of cases (n = 21), of which 14.2% (n = 3) had VUR and 52% (n = 11) had DSD. VUR was diagnosed in 16% (n = 4) of patients (3 unilateral and 1 bilateral). Among those patients with VUR, 25% (n = 1) had bilateral hydroureteronephrosis, 25% (n = 1) had thickened irregular bladder, and 50% (n = 2) had DSD. Overall patients with DSD had worst VUDS parameters. Overactive detrusor and normal sphincter, n = 8 (33%), was the most common type of neurogenic bladder in our study. On statistical analysis, there were positive correlations found between the VUDS parameters such as leak point volume, bladder capacity, bladder compliance, and DSD with sonological deterioration of the upper and lower urinary tracts (significant PVRU, hydronephrosis, and bladder wall thickening) as well as serum urea and creatinine levels.

VUDS is decisive for the therapeutic strategy as it allows the definition of the dysfunctional pattern of the lower urinary tract and detection of risk factors to enable the prevention of major upper urinary tract changes by appropriate treatment. VUDS should be a part of standard evaluation protocol in all patients of neurogenic bladder.