Upper urinary tract protection in neurogenic lower urinary tract dysfunction (NLUTD) is typically inferred from bladder parameters. Measurement of ureteral contractile dynamics during bladder filling has not been routinely performed. We sought to develop a dual-microcatheter technique to quantify ureteral pressure-time activity at the intradetrusor and proximal ureter and to explore modulation during bladder filling in patients with and without NLUTD.

Patients undergoing clinically-indicated fluoroscopic urodynamics were prospectively recruited under institutional review board approval. A dual-sensor microcatheter system was positioned to obtain intradetrusor ureteral pressure recordings at the level of the ureteral tunnel, followed by recordings in the proximal ureter together with bladder during controlled bladder filling (Figure). Pressure signals were acquired.  For each ureteral contraction, contraction amplitude, pulse width, and contraction frequency were measured. To quantify overall ureteral activity, an integrated pressure-time index per minute was calculated using a half-sine approximation (cmH₂O·sec/min). Patients without stable pressure recordings were excluded from analysis. Group comparisons were performed using Welch’s t-tests, and paired analyses were used where appropriate.

Ten patients were included: eight with analyzable intramural recordings and five with proximal filling data. Tunnel pressure-time index/min was lower in NLUTD patients (≈76 vs 118 cmH₂O·sec/min; p=0.22; Cohen’s d≈1.0). Some patients demonstrated compensatory peristaltic activity; others exhibited increased ureteral baseline pressure without corresponding increases in peristaltic activity, suggesting variable bladder-ureter coupling.

Preliminary measurements suggest that ureteral contractile activity within the intradetrusor tunnel may be diminished in patients with NLUTD. The observed heterogeneity in ureteral responses to bladder filling, including compensatory increases in peristalsis in some patients and elevated baseline ureteral pressure without increased contractility in others, suggests that bladder-ureteric coupling varies across individuals. These findings raise the possibility that impaired ureteral mechanical activity, rather than bladder pressure alone, may contribute to upper urinary tract deterioration in NLUTD.

Direct measurement of ureteral pressure-time activity during bladder filling is feasible using a dual-microcatheter approach. Early results suggest that altered ureteral dynamics may represent an underrecognized component of upper tract protection in NLUTD, warranting larger investigations to define ureteral functional phenotypes associated with upper tract risk.