Sacral neuromodulation using the standardized tined lead implantation technique with a curved vs a straight stylet: 2-year clinical outcomes and sensory responses to lead stimulation

OBJECTIVES: To assess clinical follow-up data over 24 months, comparing the use of a curved vs straight stylet in patients undergoing sacral neuromodulation using the standardized tined lead implantation technique. PATIENTS AND METHODS: We conducted a single tertiary-centre, prospective study between August 2013 and June 2015 involving 40 patients with overactive bladder and 15 with non-obstructive urinary retention refractory to first-line treatment. The primary outcome was successful tined lead procedure according to intention-to-treat analyses at 12 and 24 months. The secondary outcome was number of optimal electrode configurations during programming. Statistical analysis was performed using plain non-parametric tests for numerical and categorical data. RESULTS: Successful tined lead procedures were achieved in 33 of 35 patients (94%) implanted with the curved stylet compared with 13 of 20 patients (65%) implanted with the straight stylet (P = 0.005). Intention-to-treat analyses at 12 and 24 months showed success rates of 94% and 91%, respectively, in the curved stylet group vs 65% and 45%, respectively, in the straight stylet group (P = 0.002 and P < 0.001). In the curved stylet group, 60% and 25% of the electrode configurations were considered optimal and poor, respectively, vs 40% and 37%, respectively, in the straight stylet group (P < 0.001). CONCLUSIONS: The use of the standardized implantation technique with the curved stylet led to more successful tined lead procedures, better success rates after 2 years of follow-up and a greater number of optimal electrode configurations when compared to use of the straight stylet.