Infection Rate of a Prolonged Sacral Neuromodulation Test: A Large Retrospective Study.

OBJECTIVES: It is estimated that 3.8% to 12.5% of patients develop a device infection during the two to four weeks of the sacral neuromodulation (SNM) test, leading to removal of the entire system. It is possible to prolong the test phase up to the clinician's decision, particularly when benefits are unclear. The aim of our study is to assess the device infection rate in a prolonged SNM test. MATERIALS AND METHODS: We retrospectively enrolled patients who performed a prolonged SNM test (at least eight weeks) in the last five years (2017-2021). All procedures were performed using a standardized technique and the same prophylactic antibiotic protocol. In case of a clinical suspicion of infection, all components were explanted. Patient information (age at implantation, medical history of diabetes, metabolic syndrome, immunologic diseases, or chronic immunosuppressive therapy), surgical data (operative time, intraoperative complications), and infection data (timing of onset, symptoms reported, wound culture results) were recorded. RESULTS: We enrolled 232 patients who underwent a prolonged SNM test (mean duration 65.5 days). A local infection that led to the removal of the entire system occurred in six patients (2.6%). The gluteal pocket was always involved, and in two cases, infection was also extended to the exit point of the extension wire. No significant correlations with clinical data were found. Infection occurred beyond four weeks in two cases, between three and four weeks in three cases, and within two weeks in one case. Intraoperative wound culture was performed in five of six patients, and Staphylococcus aureus (S aureus) was isolated in four cases. One culture test gave negative bacterial growth results. CONCLUSIONS: The infection rate of a prolonged eight-week SNM test is low and does not differ from that reported in the literature for a two-to-four-week SNM test. S aureus remains the most frequent bacterium involved.

Do you really want to deactivate your sacral neuromodulation device during pregnancy? A single center case series.

INTRODUCTION AND HYPOTHESIS: The main objective of the study is to assess the efficacy and safety of sacral neuromodulation (SNM) during pregnancy. METHODS: We retrospectively enrolled patients who underwent SNM implantation in our center and subsequently became pregnant. The indication for SNM, timing of device de-activation (if performed), course of pregnancy and urological complications, duration of labor, childbirth term, delivery mode, congenital abnormalities and SNM dysfunctions after delivery were recorded. RESULTS: Fourteen pregnancies were recorded among 11 women undergoing SNM. Indications for device implantation were urinary retention (7 cases) and dysfunctional voiding (4 cases). Two patients carried on two and three pregnancies, respectively, with the device turned off since the first trimester. They both had to return to self-catheterization and developed recurring urinary tract infections. No major urological complications were recorded among the remaining nine women that kept the device on during pregnancy. A cesarean section was performed in four cases for obstetric reasons, and in seven cases it was planned by the urologist and gynecologist to avoid lead damage/displacement. Three pregnancies resulted in a vaginal delivery, and no association with term of delivery or duration of labor was observed. No congenital abnormalities related to SNM or lead displacement are reported, and only one patient required device removal because of significant loss of efficacy after childbirth. CONCLUSIONS: The use of SNM during pregnancy appears to be safe, without morbidity for the fetus. Moreover, risks associated with switching the device off may be greater than benefits and justify maintaining the electrical stimulation throughout pregnancy.

Sacral neuromodulation to treat voiding dysfunction in patients with previous pelvic surgery for deep infiltrating endometriosis: our centre's experience.

INTRODUCTION AND HYPOTHESIS: Voiding symptoms/dysfunctions (VS/Ds) after surgery for deep-infiltrating endometriosis (DIE) are frequent (20% of patients) and, together with bowel dysfunctions, may represent a de novo disorder due to surgical damage of the pelvic plexus or a worsening of pre-existent functional damage. Sacral neuromodulation (SNM) might improve voiding symptoms by treating dysfunctional voiding. The aim of this study is to report our experience with SNM in patients treated with surgery for DIE. METHODS: We retrospectively enrolled 13 patients with VS/Ds after surgery for DIE. All patients were investigated with urodynamic studies (UDS) and agreed to undergo SNM. Pre-existing VS/Ds, bowel disorders and pelvic pain, DIE surgical procedures, UDS and SNM test results were recorded. RESULTS: After surgery for DIE, functional bladder outflow obstruction and detrusor acontractility were observed in nine and four patients, respectively. Chronic pelvic pain was present in seven cases. Twelve patients developed constipation, whilst one patient had de novo faecal incontinence. After the SNM testing period, nine patients (69.2%) experienced a significant improvement of symptoms that led to definitive implant. Four patients (30.8%) had no symptom relief and the system was removed. CONCLUSIONS: Functional bladder outflow obstruction and urinary retention are the most common VS/Ds after surgery for DIE. SNM may be an effective option for these patients, probably due to its action in improving the dysfunctional voiding, which was likely to be already present as part of the "endometriotic syndrome" and got worse after pelvic surgery. Results for pelvic pain control and gastrointestinal disorders should not be underestimated.

Detrusor acontractility in urinary retention: detrusor contractility test as exclusion criteria for sacral neurostimulation.

PURPOSE: Results of sacral neurostimulation in urinary retention are reported in the literature without distinction between the 2 functional disorders causing this condition, detrusor acontractility and functional outlet obstruction. We have suggested a stimulation test to differentiate irreversible bladder myopathy (or complete neurogenic lesion) from potential bladder contractility eligible for sacral neurostimulation. MATERIALS AND METHODS: Direct electrostimulation of the sacral nerves was performed with the patient under general anesthesia. Urodynamic monitoring of bladder (detrusor contractility test) and bowel pressures were used. If no bladder contraction (negative detrusor contractility test) was recorded with positive somatic and bowel responses a irreversible bladder myopathy was supposed and the patient discharged home. If no bladder and no bowel contraction were recorded a complete neurogenic lesion was supposed and the patient was also discharged. RESULTS: Of 96 patients tested with the detrusor contractility test 72 (65%) had no bladder contraction and were excluded from sacral neurostimulation therapy. In this series 15 patients had already been tested with percutaneous nerve evaluation on each S3 nerve with negative results. In 18 cases no bladder and no bowel contraction was evoked (neurogenic lesion). In the remaining 54 cases (bowel but no bladder contraction) a bladder myopathy was supposed. In 24 patients the detrusor contractility test was positive and 12 of these underwent implantation with a permanent device for sacral neurostimulation. CONCLUSIONS: The detrusor contractility test can be considered a reliable tool to rule out detrusor acontractility due to irreversible bladder myopathy or complete neurogenic lesion from sacral neurostimulation.