Replacement Adaptor 09106 for patients with a dynamic graciloplasty or patients with sacral neuromodulation and abdominal implantable pulse generators: a retrospective, single centre, Stage 2a/2b development IDEAL case series.

AIM: Due to the introduction of a new implantable pulse generator (IPG), the Interstim II, patients with either a dynamic graciloplasty or an abdominally placed IPG for sacral neuromodulation could not undergo surgery to replace their IPG in the case of end of battery life. For these patients, the Medtronic Replacement Adaptor 09106 was created. This retrospective case series aims to study safety and feasibility of the Medtronic Replacement Adaptor 09106 in patients with abdominally placed IPGs. METHODS: Seventeen patients (11 women, six men) received a replacement adaptor with a follow-up of 6 months. Outcome measures consisted of a bowel habit diary. Adverse events were classified using the Clavien-Dindo classification. RESULTS: Outcome measures in the bowel habit diaries after replacement (feasibility) did not differ significantly from outcome measures before replacement. Adverse events occurred in four out of 17 patients (24%): two patients initially showed pocket site pain (Clavien-Dindo Grade I), which resolved without intervention. One patient suffered from poor wound closure (Clavien-Dindo Grade II) and one patient had persisting pocket pain (Clavien-Dindo Grade IIIa) for which a pocket revision was performed. Statistical analyses were performed making paired comparisons using a Wilcoxon signed rank test. CONCLUSION: The Medtronic Replacement Adaptor 09106 is a valuable option for patients with dynamic graciloplasty or sacral neuromodulation and abdominal IPG and has complication rates similar to replacement of the Interstim without Replacement Adaptor 09106.

Vaginal distention rodent model for fecal incontinence: a pilot study on the effect on defecation behavior

Objectives: Vaginal balloon inflation simulates the compressive forces on the pelvic floor during the second phase of natural delivery. The foremost use of this animal model of vaginal distention (VD) is to study the mechanisms underlying urinary incontinence. As damage to the pelvic floor during natural birth is a common cause of fecal incontinence, the present paper aimed to investigate the effect of VD on defecation behavior in adult rats. Methods: Vaginal distention was performed in 8 rats for 2 hours, and in 3 rats for 4 hours, and sham inflation was performed in 4 rats. With the use of a latrine box in the rat home-cage and 24/7 video tracking, the defecation behavior was examined. The time spent in and outside the latrine was monitored for two weeks preoperatively and three weeks postoperatively, and a defecation behavior index (DBI; range: 0 [continent] to 1 [incontinent]) was defined. Pelvic floor tissue was collected postmortem and stained with hematoxylin and eosin. Results: Vaginal balloon inflation for 2 hours resulted in fecal incontinence in 29% of the animals (responders) whereas the DBI scores of non-responders (71%) and control animals did not change in the postoperative phase compared with the baseline score. A 4-hour balloon inflation resulted in fecal incontinence in 1 animal and caused a humane endpoint in 2 animals with markedly more tissue damage in the 4-hour responder compared with the 2-hour responders. Conclusions: Vaginal balloon inflation, with an optimum duration between 2 and 4 hours, can be used as a model to study changes in defecation behavior in rats induced by pelvic floor damage. (AU)

Conventional Dorsal Root Ganglion Stimulation in an Experimental Model of Painful Diabetic Peripheral Neuropathy: A Quantitative Immunocytochemical Analysis of Intracellular γ-Aminobutyric Acid in Dorsal Root Ganglion Neurons.

BACKGROUND AND OBJECTIVE: The sensory cell somata in the DRG contain all equipment necessary for extensive GABAergic signaling and are able to release GABA upon depolarization. With this study, we hypothesize that pain relief induced by conventional dorsal root ganglion stimulation (Con-DRGS) in animals with experimental painful diabetic peripheral neuropathy is related to the release of GABA from DRG neurons. With use of quantitative immunocytochemistry, we hypothesize DRGS to result in a decreased intensity of intracellular GABA-immunostaining in DRG somata. MATERIALS AND METHODS: Female Sprague-Dawley rats (n = 31) were injected with streptozotocin (STZ) in order to induce Diabetes Mellitus. Animals that developed neuropathic pain after four weeks (Von Frey) were implanted with a unilateral DRGS device at L4 (n = 14). Animals were then stimulated for 30 min with Con-DRGS (20 Hz, pulse width = 0.2 msec, amplitude = 67% of motor threshold, n = 8) or Sham-DRGS (n = 6), while pain behavior (von Frey) was measured. DRGs were then collected and immunostained for GABA, and a relation to size of sensory cell soma diameter (small: 12-26 µm, assumed to be C-fiber related sensory neurons; medium: 26-40 µm, assumed to be Aδ related sensory neurons; and large: 40-54 µm, assumed to be Aß related sensory neurons) was made. RESULTS: DRGS treated animals showed significant reductions in STZ-induced mechanical hypersensitivity. No significant differences in GABA immunostaining intensity per sensory neuron cell soma type (small-, medium-, or large-sized) were noted in DRGs of stimulated (Con-DRGS) animals versus Sham animals. No differences in GABA immunostaining intensity per sensory cell soma type in ipsi- as compared to contralateral DRGs were observed. CONCLUSION: Con-DRGS does not affect the average intracellular GABA immunofluorescence staining intensity in DRG sensory neurons of those animals which showed significant pain reduction. Similarly, no soma size related changes in intracellular GABA immunofluorescence were observed following Con-DRGS.

Sacral Neuromodulation for Lower Urinary Tract and Bowel Dysfunction in Animal Models: A Systematic Review With Focus on Stimulation Parameter Selection.

OBJECTIVE: Conventional sacral neuromodulation (SNM) has shown to be an effective treatment for lower urinary tract and bowel dysfunction, but improvements of clinical outcome are still feasible. Currently, in preclinical research, new stimulation parameters are being investigated to achieve better and longer effects. This systematic review summarizes the status of SNM stimulation parameters and its effect on urinary tract and bowel dysfunction in preclinical research. MATERIALS AND METHODS: The literature search was conducted using three databases: Ovid (Medline, Embase) and PubMed. Articles were included if they reported on stimulation parameters in animal studies for lower urinary tract or bowel dysfunction as a primary outcome. Methodological quality assessment was performed using the SYRCLE Risk of Bias (RoB) tool for animal studies. RESULTS: Twenty-two articles were eligible for this systematic review and various aspects of stimulation parameters were included: frequency, intensity, pulse width, stimulation signal, timing of stimulation, and unilateral vs. bilateral stimulation. In general, all experimental studies reported an acute effect of SNM on urinary tract or bowel dysfunction, whereas at the same time, various stimulation settings were used. CONCLUSIONS: The results of this systematic review indicate that SNM has a positive therapeutic effect on lower urinary tract and bowel dysfunction. Using low-frequency-SNM, high-frequency-SNM, bilateral SNM, and higher pulse widths showed beneficial effects on storage and evacuation dysfunction in animal studies. An increased variability of stimulation parameters may serve as a basis for future improvement of the effect of SNM in patients suffering from urinary tract or bowel dysfunction.

Stimulation Parameters for Sacral Neuromodulation on Lower Urinary Tract and Bowel Dysfunction-Related Clinical Outcome: A Systematic Review.

OBJECTIVE: Sacral neuromodulation (SNM) has been used to treat patients with lower urinary tract dysfunction and bowel dysfunction for many years. Success rates vary between 50% and 80%, indicating that there is much room for improvement. Altering stimulation parameters may result in improved outcome. This paper reports a systematic review of the clinical efficacy of nonconventional stimulation parameters on urinary tract and bowel dysfunction. MATERIALS AND METHODS: Three databases were used for the literature search: Ovid (Medline, Embase) and PubMed. Papers were screened by two independent reviewers, who also extracted data from these papers. Clinical papers studying SNM stimulation parameters, that is, intermittent stimulation, frequency, pulse width, and amplitude, in urinary tract and bowel dysfunction were included. Quality of included papers was assessed using standardized guidelines. RESULTS: Out of 5659 screened papers, 17 papers, studying various stimulation parameters, were included. Overall quality of these papers differed greatly, as some showed no risk of bias, whereas others showed high risk of bias. Stimulation parameters included intermittent stimulation, frequency, pulse width, amplitude, and unilateral vs. bilateral stimulation. Especially high frequency SNM and either a narrow or wide pulse width seem to improve efficacy in patients with bowel dysfunction. Additionally, implementation of short cycling intervals is promising to improve quality of life for patients with urinary tract or bowel dysfunction. CONCLUSION: The results of our systematic review indicate that stimulation parameters may improve efficacy of SNM in treatment of both urinary tract dysfunction and bowel dysfunction.