Study design, materials and methods
1.Between May 2017 to August 2018,10 female patients with diabetic bladder dysfunction were treated with SNM therapy. The symptom improvement of pretherapy, phase I (testing phase), phase II (post permanent stimulator implantation ) were compared and the safety of SNM in such patients was observed.
2.Surgical methods:Phase I (testing phase):The electrode extension line is connected with the temporary stimulator, and the parameters of the stimulator are adjusted. The parameter setting needs to meet the principle of weak stimulation of the perianal and no interference of the lower limbs. Different sites are used as the positive and negative electrodes respectively. A combination of the above principles and a small voltage is tested for 1 to 4 weeks. Urinary diaries and symptom changes were recorded throughout the testing period, and residual urine volume was reviewed. Patients with more than 50% improvement in clinical symptoms were defined as effective. Phase II permanent stimulator implantation may be considered; if the symptom is improved by less than 50%, the effect is poor, and the electrode is taken out within 4 weeks.
Phase II (post permanent stimulator implantation ): The patient takes the prone position, disinfects the single sheet, and connects the original electrode to the extension wire. Open and slightly enlarge the incision, taking care not to accidentally damage the electrode, and separate and remove the extension wire. The blunt dissection was used to make a subcutaneous pocket (deep fascia deep), the electrode and permanent stimulator were connected, the stimulator was placed in a subcutaneous pocket, the impedance was measured, and the incision was closed after confirming that the system was intact.
After the permanent stimulator is implanted, four sets of parameters are set according to the principle of phase I parameter setting, and the patient is informed to preferentially select a set of parameters with better therapeutic effect and relatively low voltage. When the symptoms are repeated, the voltage is first selected first, and if it is invalid, it can be self-selected. Change the stimulation parameter group. If the 4 groups of parameters are not effective after use, it is recommended that the patient go to the programmer to perform parameter programming.
3.All patients were required to record the urination diary before and after treatment, at least for 3 days, including the number of daily urination, the amount of urine per urination, and the quality of life (QOL). B-ultrasound was used to evaluate the residual urine volume before and after treatment, and the dysuria score was recorded. The dysuria and urine waiting degree were divided into 0 to 10 points, the 10 points were the heaviest, and the 0 points were the lightest. The patients were selected according to the degree of dysuria.
Interpretation of results
In the study, we treated 10 patients with DBD with SNM. The stage I electrode implantation was successfully completed. During the test, the urination effort rate was 60%, the urination frequency was 40%, and the residual urine volume was 65%. The efficiency was 55%; 6 of them were tested with a second-stage permanent stimulator, and the conversion rate was 60% (6/10). The risk of surgery in diabetic patients is higher than that of the general patients, mainly due to the increased incidence of wound infection, and the incidence of device removal due to infection is higher in diabetic patients (37.5 vs. 25.5%). In this study, no significant complications were observed, which may be related to good glycemic control, strict aseptic procedures, and perioperative management, indicating that this procedure is safe and feasible for diabetic patients.