Safety of Magnetic Resonance Imaging in patients under Sacral Neuromodulation with an InterStim Neuromodulator.

OBJECTIVE: To retrospectively investigate the safety of magnetic resonance imaging (MRI) in patients under sacral neuromodulation (InterStim II). METHODS: Data of patients who received a sacral neuromodulator at the urological department of a Swiss center of tertiary care from 2007 to 2018 and subsequently received at least 1 MRI with implanted device were retrospectively analyzed. Patient characteristics, data on implantation, MRI characteristics and complications potentially related to the MRI were analyzed. In addition, patient interviews were performed to verify the data gathered from patient records. RESULTS: A total of 55 consecutive patients with a median age of 48 years (range 16 - 80 years) and a total of 191 MRIs (median 3, range 1 - 13) were included to the study. The majority of MRIs (92%) were performed with 1.5 Tesla. The majority of the 1.5 Tesla (58%) as well as 3 Tesla (56%) MRIs assessed body regions other than the head. Complication possibly related to the MRI were only found in 2 (1%) MRI scans in two patients who reported on transient electrifying pain and heat sensation at the implantation site of the neuromodulator during MRI. CONCLUSION: MRI scans in patients with an implanted InterStim II sacral neuromodulator and with the device being turned off seem to be safe, even if they involve body regions other than the head, at least with 1.5 Tesla.

Is intravesical stent position a predictor of associated morbidity?

PURPOSE: Temporary drainage of the upper urinary tract by use of internal ureteral stents is a common procedure that is often associated with a variety of symptoms. The role of intravesical stent position in associated morbidity is controversial. MATERIALS AND METHODS: The German version of the ureteral stent symptom questionnaire (USSQ) was completed by 73 patients with an indwelling ureteral stent the day before stent removal. Intravesical stent position was classified into 3 categories by x-ray before stent removal. The influence of intravesical stent position on USSQ score was analyzed, including subscores and single items. RESULTS: Intravesical stent position showed no significant influence on associated morbidity. The median USSQ total score in all patients was 77.5 (range, 30-147). Patients with ipsilateral stents (69.0; range, 30-122) tended to have lower total scores than did those with tangential (86.5; range, 30-122) or contralateral (77.0; range, 31-147) stents, but the differences were not statistically significant (p=0.35). The USSQ subscores for urinary symptoms (p=0.80), body pain (p=0.80), general health (p=0.16), work performance (p=0.07), additional problems (p=0.81), and all of the USSQ single items of interest in the context of stent length also did not differ significantly between the three groups. CONCLUSIONS: Intravesical stent position did not significantly influence associated morbidity in our study. An appropriate stent length should be chosen to avoid dislocation. However, complex calculations of optimum stent length, time-consuming manipulations, and costly stock holding of various stent sizes to obtain the perfect stent position do not seem worthwhile.

Influence of patient education on morbidity caused by ureteral stents.

OBJECTIVES: To investigate the influence of patient education on symptoms and problems caused by ureteral stents. METHODS: The German version of the Ureteral Stent Symptom Questionnaire was completed by 74 patients with unilateral inserted indwelling stents. Additionally, six self-developed questions regarding type and quality of patient education on pain, urinary symptoms, hematuria, activities permitted, stent function and overall patient education were answered. Correlations between questionnaires, subscores and single items, and the influence on economic aspects were analyzed. RESULTS: Adjusting for age, sex, intravesical stent length, stent indwelling time, use of analgesics and an alpha-blocker, the correlation between the Ureteral Stent Symptom Questionnaire and self-developed questions was -0.40 (95% CI -0.58, -0.19, P < 0.001). The following subscores and items showed a statistically significant correlation with quality of patient education after correction for multiple testing: Ureteral Stent Symptom Questionnaire total score, urinary symptoms subscore, U6, U10, G3, G4 and GQ. No relevant influence of patient education on economic aspects was found. CONCLUSION: High-quality patient education on ureteral stent-related symptoms is highly advisable, as it has the potential to reduce these symptoms. However, the influence of information on the incidence and extent of potential problems seems to be limited. A much better approach would be to develop better designed devices and more convenient stent-free procedures.