Sacral Nerve Research Articles

Real-life after sacral nerve modulation implantation: Rate, reasons, and risk factors for mid-term follow-up discontinuation

To evaluate follow-up after implantation of a sacral nerve modulation implantable pulse generator (IPG) and to investigate the reasons and risk factors for follow-up discontinuation. All patients who underwent an IPG implantation to treat lower urinary tract symptoms between 2014-2019 within 6hospital centers located in the district of "Hauts-de-France" (France) were systematically called during the year 2020 for a standardized (tele)consultation. Patients were divided into 3 distinct profiles according to the regularity of their 5-year postoperative follow-up: "Regular follow-up", "Irregular follow-up" and "Lost to follow-up". The primary outcome was the change in the annual proportion of the 3 follow-up profiles over the 5 years following IPG implantation. As secondary outcomes we described the reasons reported for follow-up discontinuation and looked for risk factors associated with. Overall, 259 patients were included. At the time of data collection, after a mean follow-up of 28.4 (±19.8) months, 139 patients (53.7%) had a "Regular follow-up", 54 (20.8%) had an "Irregular follow-up" and 66 (25.5%) were "Lost to follow-up". The proportion of patients with a "Regular follow-up" decreased year by year, representing only 46.2% of patients at five-years. 175 patients (67.6%) underwent a standardized (tele)consultation. In multivariate analysis, only "lack of knowledge of the follow-up protocol" was statistically associated with follow-up discontinuation (OR=5.16; 95% CI [2.12-13.57]). The proportion of patients followed up after IPG implantation decreased steadily over the years, often related to a lack of therapeutic education.

Intraoperative Monitoring of the External Urethral Sphincter Reflex: A Novel Adjunct to Bulbocavernosus Reflex Neuromonitoring for Protecting the Sacral Neural Pathways Responsible for Urination, Defecation and Sexual Function.

Intraoperative bulbocavernosus reflex neuromonitoring has been utilized to protect bowel, bladder, and sexual function, providing a continuous functional assessment of the somatic sacral nervous system during surgeries where it is at risk. Bulbocavernosus reflex data may also provide additional functional insight, including an evaluation for spinal shock, distinguishing upper versus lower motor neuron injury (conus vs. cauda syndromes) and prognosis for postoperative bowel and bladder function. Continuous intraoperative bulbocavernosus reflex monitoring has been utilized to provide the surgeon with an ongoing functional assessment of the anatomical elements involved in the S2-S4 mediated reflex arc including the conus, cauda equina and pudendal nerves. Intraoperative bulbocavernosus reflex monitoring typically includes the electrical activation of the dorsal nerves of the genitals to initiate the afferent component of the reflex, followed by recording the resulting muscle response using needle electromyography recordings from the external anal sphincter. Herein we describe a complementary and novel technique that includes recording electromyography responses from the external urethral sphincter to monitor the external urethral sphincter reflex. Specialized foley catheters embedded with recording electrodes have recently become commercially available that provide the ability to perform intraoperative external urethral sphincter muscle recordings. We describe technical details and the potential utility of incorporating external urethral sphincter reflex recordings into existing sacral neuromonitoring paradigms to provide redundant yet complementary data streams. We present two illustrative neurosurgical oncology cases to demonstrate the utility of the external urethral sphincter reflex technique in the setting of the necessary surgical sacrifice of sacral nerve roots.

A Comparative Gross Study on the Sacral Plexus of the Magpie (Pica Pica) and Chukar Partridge (Alectoris Chukar)

In poultry, sacral plexus usually occurs as a result of a combination of ventral branches of 1-5 sacral spinal nerves. The aim of this study is comparatively determination the sacral plexus and its branches of magpie (Pica pica) and chukar partridge (Alectoris chukar) and anatomic differences between two species. In the present study, there were used 20 magpies (Pica pica) and 20 chukar partridges (Alectoris chukar). All animals were sacrificed under anesthesia and the nerves forming sacral plexus were separately dissected and photographed in the both species. In the present study, it was determined that forming of sacral plexus and general anatomic distribution of nerves arising from plexus in the both species were similar with other many bird species. However, nerves forming the sacral plexus and their branches were thicker in chukar partridge than magpie.

Comparative Effectiveness of Combined Lumbar- Para Sacral Nerve Block and Spinal Anaesthesia on the Pain Intensity and Duration of Anaesthesia in Patients with Tibial Fracture

Background: The aim of this study was to evaluate the effect of combined lumbar plexus– para sacral nerve block (LP/NB) and spinal anaesthesia (SA) on the duration and intensity of postoperative pain in patients with Tibia fracture requiring surgery.
 Methods: In this clinical trial, 40 patients with tibial fractures requiring surgery, who were admitted to a referral hospital in north-eastern Iran from 2020 to 2021, and randomly subjected to LP/NB or spinal anaesthesia. Pain intensity and duration of anaesthesia in the two groups were compared based on a numerical rating scale within 4, 6 and 12 hours from the induction of anaesthesia. Clinical demand for analgesics following surgery was also recorded. Data were statistically analysed with IBM SPSS.
 Results: The mean age of participants was 37.4 ±14.4, with 29 (72.5%) and 11 (27.5%) male and female patients, respectively. There were no significant differences in age and sex ratio between the two groups. The mean pain intensity within 4 hours from surgery was lower in the LP/NB group, however, this difference was not statistically significant (p-value: 0.054). Likewise, there were also no significant differences between the values reported for 6 (p-value: 0.303) and 12-hour (p-value: 0.523) post-surgery pain intensity for each group. Overall, the mean pain intensity at any given time was not significantly different between the two groups of LP/NB and SA (p-value: 0.671).
 Conclusion: There was no significant difference between the two groups in terms of mean pain intensity at 4, 6 and 12 hours after the onset of the block. No side effects were observed in any of the patients.

Anatomical Analysis of the S1 Neural Foramen Using Three-Dimensional Computed Tomography Imaging: Insights for Effective S1 Nerve Root Block

The first sacral nerve root block (S1 NRB) is used to diagnose and treat lumbosacral and radicular pain. This study aims to clarify the anatomy of the S1 neural foramen using three-dimensional (3D) computed tomography (CT) images and to establish the optimal fluoroscopic angle, localize the S1 neural foramen on fluoroscopy, and determine the safe puncture depth for S1 NRB. In this single-center cohort study, 200 patients with lumbar degenerative disease who underwent preoperative CT were enrolled. Four distinct studies were conducted using the CT data. Study 1 examined the correlation of the sacral slope angle and the supine and prone positions. Study 2 analyzed the tunnel view angle (TVA) using 3D reconstruction. Study 3 ascertained the location of the S1 neural foramen in fluoroscopy images. Study 4 investigated the safe depth for performing S1 NRB. The regression analysis in Study 1 revealed a correlation of the sacral slope angle and the supine and prone positions. Study 2 determined an optimal fluoroscopic TVA of approximately 30° for the S1 NRB. Study 3 found that the S1 neural foramen was located caudal to the L5 pedicle 1.7±0.2 times the distance between the L4 and L5 pedicles. Study 4 revealed that the depths of the S1 neural foramen and root were 27.0±2.1mm and 16.5±2.0mm, respectively. Our study suggests an optimal fluoroscopic angle, a simple method to locate the S1 neural foramen on fluoroscopy, and an ideal puncture depth for a safe and effective S1 NRB.

Clinical outcomes of 3T magnetic resonance imaging-guided lumbar and sacral foraminal injections

PurposeThis article evaluates the feasibility, safety, and efficacy of MRI-guided lumbar or sacral nerve root infiltration for chronic back pain. We compared the outcomes of our MRI-guided infiltrations with data from CT-guided infiltrations reported in the literature and explored the potential advantages of MRI guidance.MethodForty-eight MRI-guided nerve root infiltrations were performed using a 3 T MRI machine. The optimal needle path was determined using breathhold T2-weighted sequences, and the needle was advanced under interleaved guidance based on breathhold PD-weighted images. Pain levels were assessed using a numeric rating scale (NRS) before the procedure and up to 5 months after, during follow-up. Procedure success was evaluated by comparing patients’ pain levels before and after the infiltration.ResultsThe MRI-guided infiltrations yielded pain reduction 1 week after the infiltration in 92% of cases, with an average NRS substantial change of 3.9 points. Pain reduction persisted after 5 months for 51% of procedures. No procedure-related complications occurred. The use of a 22G needle and reconstructed subtraction images from T2 FatSat sequences improved the workflow.ConclusionOur study showed that MRI-guided nerve root infiltration is a feasible, safe, and effective treatment option for chronic back pain. Precise positioning of the needle tip and accurate distribution of the injected solution contributed to the effectiveness of MRI-guided infiltration, which appeared to be as accurate as CT-guided procedures. Further research is needed to explore the potential benefits of metal artifact reduction sequences to optimize chronic back pain management.

Applied anatomy of female pelvic plexus for nerve-sparing radical hysterectomy(NSRH)

BackgroundNerve-sparing radical hysterectomy(NSRH)has the advantage of reducing postoperative complications and improving postoperative quality of life. The separation and protection of the pelvic plexus in NSRH is extremely important and challenging.Methods24 female cadaveric hemipelves were dissected. Morphologic patterns and compositions of pelvic plexus as well as relationship of pelvic plexus to the surrounding structures were observed and documented.ResultsTwo patterns of superior hypogastric plexus were observed, including fenestrated and cord-like shape. The origin of bilateral hypogastric nerves were inferiorly to upper margin of promontory about 1.6 ± 0.1 cm and parallel to the ureter in front of the sacrum. Pelvic splanchnic nerves(PSN)from the second sacral nerve, the third sacral nerve and the forth sacral nerve were observed combing with the hypogastric nerves within the lateral rectal ligament. The sacral sympathetic trunk can be identified anteriorly or medially to the anterior sacral foramen. We identified the boundaries of pelvic plexus as following: the upper margin is formed by the PSNs from the third sacral nerve, posterior margin by inferior rectal artery, and anteriorly by vesical venous plexus. The uterine branches from pelvic plexus were observed accompanying with uterine artery, while other branches were inferiorly to the artery. The PSNs were located beneath the deep uterine veins within the cardinal ligament. The upper margin of pelvic plexus was observed directly approach to urinary bladder within the vesico-vaginal ligament as a single trunk accompanying with ureter, between the middle and inferior vesical veins.ConclusionsOur study clarified the intricate arrangement, distribution and relationship of female pelvic plexus and the related structures to provide reference index for NSRH application. The innervation patterns of bladder and uterine were clarified, and by tracing these visceral branches of pelvic plexus, we suggest several new important land markers for NSRH.

Pathways and parameters of sacral neuromodulation in rats.

The stimulation paradigm for sacral neuromodulation has remained largely unchanged since its inception. We sought to determine, in rats, whether stimulation-induced increases in bladder capacity correlated with the proportion of sensory pudendal (PudS) neurons at each stimulated location (L6, S1). If supported, this finding could guide the choice of stimulation side (left/right) and level (S2, S3, S4) in humans. Unexpectedly, we observed that acute stimulation at clinically relevant (low) amplitudes [1-1.5 × motor threshold (Tm)], did not increase bladder capacity, regardless of stimulus location (L6 or S1). More importantly for the ability to test our hypothesis, there was little anatomic variation, and S1 infrequently contributed nerve fibers to the PudS nerve. During mapping studies we noticed that large increases in PudS nerve activation occurred at amplitudes exceeding 2Tm. Thus, additional cystometric studies were conducted, this time with stimulation of the L6-S1 trunk, to examine further the relationship between stimulation amplitude and cystometric parameters. Stimulation at 1Tm to 6Tm evoked increases in bladder capacity and decreases in voiding efficiency that mirrored those produced by PudS nerve stimulation. Many animal studies involving electrical stimulation of nerves of the lower urinary tract use stimulation amplitudes that exceed those used clinically (∼1Tm). Our results confirm that high amplitudes generate immediate changes in cystometric parameters; however, the relationship to low-amplitude chronic stimulation in humans remains unclear. Additional studies are needed to understand changes that occur with chronic stimulation, how these changes relate to therapeutic outcomes, and the contribution of specific nerve fibers to these changes.NEW & NOTEWORTHY Acute low-amplitude electrical stimulation of sacral nerve (sacral neuromodulation) did not increase bladder capacity in anesthetized CD, obese-prone, or obese-resistant rats. Increasing stimulation amplitude correlated with increases in bladder capacity and pudendal sensory nerve recruitment. It is unclear how the high-amplitude acute stimulation that is commonly used in animal experiments to generate immediate effects compares mechanistically to the chronic low-amplitude stimulation used clinically.

A Predictive Model to Identify the Effects of Transcutaneous Sacral Nerve Stimulation With Pelvic Floor Exercises in Fecal Incontinence After Surgery for Anorectal Malformation.

Although the combination of transcutaneous sacral nerve stimulation (tSNS) and pelvic floor exercises (PFEs) has shown significant effectiveness in treating fecal incontinence (FI) after surgery for congenital anorectal malformation (CARM), not all patients achieve satisfactory continence. Therefore, identifying which individuals will benefit from this method is crucial. A prospective cohort study enrolled 92 children with FI. All patients underwent tSNS with PFE treatment, and an improved outcome was defined as a Wexner score ≤4. A predictive model to identify the effects of tSNS with PFEs in FI was developed based on the analysis of magnetic resonance imaging and high-resolution anorectal manometry with area under the receiver-operating characteristic curve to evaluate the predictive value of external anal sphincter (EAS) thickness index and anal squeezing pressure (ASP). tSNS with PFEs improved outcomes in 72 patients and led to poor outcomes in 20 (4 had their rectums deviate from the puborectalis muscle center or puborectal muscle ruptures while 16 lacked EAS with a lower ASP). The areas under the receiver-operating characteristic curve for EAS thickness index and ASP in predicting the effects of tSNS with PFEs were 0.915 (95% confidence interval 0.846-0.983, P = 0.000) and 0.886 (95% confidence interval 0.819-0.952, P = 0.000), respectively. By applying cutoff values of 0.076 for EAS thickness index and 21.95 mm Hg for ASP, tSNS with PFEs was found to be ineffective. tSNS with PFEs is effective for most patients with FI after CARM surgery, except when the rectum deviates from the puborectal muscle center, puborectal muscle rupture occurs, or EAS is absent with a low ASP.

Development of a predictive tool for sacral nerve modulation implantation in the treatment of non-obstructive urinary retention and/or slow urinary stream: a study from the Neuro-Urology Committee of the French Association of Urology.

This study aimed to seek predictive factors and develop a predictive tool for sacral nerve modulation (SNM) implantation in patients with non-obstructive urinary retention and/or slow urinary stream (NOUR/SS). This study was designed as a retrospective study including all patients who have undergone a two-stage SNM for NOUR/SS between 2000 and 2021 in 11 academic hospitals. The primary outcome was defined as the implantation rate. Secondary outcomes included changes in bladder emptying parameters. Univariate and multivariable logistic regression analysis were performed and determined odds ratio for IPG implantation to build a predictive tool. The performance of the multivariable model discrimination was evaluated using the c-statistics and an internal validation was performed using bootstrap resampling. Of the 357 patients included, 210 (58.8%) were finally implanted. After multivariable logistic regression, 4 predictive factors were found, including age (≤ 52 yo; OR = 3.31 CI95% [1.79; 6.14]), gender (female; OR = 2.62 CI95% [1.39; 4.92]), maximal urethral closure pressure (≥ 70 cmH2O; OR: 2.36 CI95% [1.17; 4.74]), and the absence of an underlying neurological disease affecting the lower motor neuron (OR = 2.25 CI95% [1.07; 4.76]). Combining these factors, we established 16 response profiles with distinct IPG implantation rates, ranging from 8.7 to 81.5%. Internal validation found a good discrimination value (c-statistic, 0.724; 95% CI 0.660-0.789) with a low optimism bias (0.013). This allowed us to develop a predictive tool ( https://predictivetool.wixsite.com/void ). The present study identified 4 predictive factors, allowing to develop a predictive tool for SNM implantation in NOUR/SS patients, that may help in guiding therapeutic decision-making. External validation of the tool is warranted.

The Effect of Caudal Ropivacaine and Morphine on Postoperative Analgesia in Total Laparoscopic Hysterectomy: A Prospective, Double-Blind, Randomized Controlled Trial.

Multiple regional nerve blocks proved no additional benefit in total laparoscopic hysterectomy in multimodal analgesia, as postoperative pain may mainly originate from the vaginal cuff. Theoretically, caudal block can relieve pain from the vaginal cuff by a sacral spinal nerve block. We aimed to verify whether a caudal block with ropivacaine and morphine can achieve an analgesic effect without additional adverse effects after a total laparoscopic hysterectomy. Forty-eight patients undergoing total laparoscopic hysterectomy were randomly allocated to receive preoperative caudal block with 20 mL of mixture including 0.25% ropivacaine and 2 mg morphine (caudal block group) or sham block (sham group). The primary outcome was the postoperative 24 h cumulative sufentanil consumption. Median (IQR) sufentanil consumption in the first 24 postoperative hours of the caudal block group and the sham group was 0.00 (0.00 to 0.05) μg/kg vs 0.13 (0.04 to 0.21) μg/kg, respectively, p < 0.001. The majority of patients felt that visceral pain was more intense than incisional pain at 1, 6, 12, and 24 h post-surgery in the sham group (95.8% at 1 h, 95.8% at 6 h, 95.8% at 12 h, and 75% at 24 h post-surgery). Compared to the sham group, the caudal block reduced visceral pain scores at rest and during movement at 1 h (p < 0.001), 6 h (p < 0.001), 12 h (p < 0.001), and 24 h (p < 0.001) post-surgery. Intraoperative remifentanil consumption was significantly lower in the caudal block group than in the sham group (p = 0.004). There were no significant differences in other secondary outcomes between the two groups. A caudal block with ropivacaine and morphine could provide a satisfactory analgesic effect for 24 h postoperatively without additional adverse effects after total laparoscopic hysterectomy.

Device evaluation: eCoin #x2013; implantable tibial nerve stimulator for overactive bladder

ABSTRACT Introduction Peripheral nerve stimulation has been demonstrated as a viable alternative to sacral nerve stimulation in managing refractory overactive bladder (OAB). New technologies allow the internalization of tibial nerve stimulators through various apparatuses. One such device, the eCoin, is a small, coin-shaped device that can be implanted adjacent to the tibial nerve that provides pre-programmed stimulation. Areas Covered We will review the literature on eCoin implantation, from proof of concept to mid-term data, with the longest period of follow-up being 12 months. All studies on this technology will be reviewed, along with an analysis of the current state of play in implantable neuromodulators for overactive bladder. Efficacy, durability, adverse events, and viability of eCoin as a long-term management option will be considered. Expert Opinion The eCoin device demonstrates promising early data for efficacy in managing overactive bladder symptoms. Complication rates remain low and are mostly related to wound healing following the initial placement of the device. Research into the continued improvement and modification of the device appears optimistic, but longer-term data still need to be obtained. Indeed, implantable PTNS have a role in the future management of overactive bladder, and devices such as eCoin will still need to prove a long-term benefit to be a mainstay of management.

Complication Pattern of Sacral Primary Tumor Resection: A Study on the Risk Factors of Surgical Site Infection and Bowel or Bladder Dysfunction and Their Associations with Length of Hospital Stay.

Retrospective open cohort study. The current study aimed to explore the pattern of complications after primary sacral tumor resection, to investigate the possible effect of several perioperative parameters on the development of complications, and to identify which complications are associated with the length of hospital stay (LOS). Primary sacral tumor (pST) resection is associated with a high complication rate. However, the number of studies on these complications and their effect on LOS is limited. The clinical data of 140 patients with pST surgeries and 106 subsequent patients with local recurrence surgeries in four subgroups (index surgery, local recurrence surgery, malignant, and benign tumor) were prospectively collected and analyzed. The prognostic value of several perioperative factors on the development of surgical site infection (SSI), bowel and bladder dysfunction (BBD), and LOS was investigated using the logistic and linear regression models. The overall complication rates were 61.2% after index surgeries and 50.9% after local recurrence surgeries. The most frequent complications were SSI, vegetative dysfunction, urinary tract infections, and neurological deterioration. Age >55 years, malignant tumors, and red blood cell transfusion had a predictive effect on the development of SSI in the logistic model (p<0.01, R2=0.43). Bilateral S2 or S3 resection commonly caused postoperative BBD (chi-square test=62.5, degrees of freedom=4, p<0.001). In the multiple linear regression model, wound dehiscence, BBD, systemic and urinary tract infection, cerebrospinal fluid leak, and neurologic deterioration were associated with a significantly long LOS (p<0.01, R2=0.62). Surgical resection of pSTs has a high complication rate. Its common complications are SSI and BBD, both of which can have a significant influence on global therapeutic outcome. Malignant tumor diagnosis, old age, and red blood cell transfusion can remarkably increase the risk of SSI. Further, the development of BBD is significantly associated with the number of resected sacral nerve roots. By decreasing perioperative complications, LOS can decrease significantly.

Oral 2 - Sacral Nerve Stimulation for Voiding Dysfunction: An initial review of a regional service in Northern Ireland

Oral 2 - Sacral Nerve Stimulation for Voiding Dysfunction: An initial review of a regional service in Northern Ireland

Sacral nerve neuromodulation: the past, present and future

Exploration and development of electrical stimulation to improve bladder and bowel function began in the early 20th century. The mechanism of action is not fully understood, but refinement and optimisation of the technique may lead to wider use in future.

Sensing in Sacral Neuromodulation: A Feasibility Study in Subjects With Urinary Incontinence and Retention

ObjectivesSacral neuromodulation (SNM) therapy standard of care relies on visual-motor responses and patient-reported sensory responses in deciding optimized lead placement and programming. Automatic detection of stimulation responses could offer a simple, consistent indicator for optimizing SNM. The purpose of this study was to measure and characterize sacral evoked responses (SERs) resulting from sacral nerve stimulation using a commercial, tined SNM lead. Materials and MethodsA custom external research system with stimulation and sensing hardware was connected to the percutaneous extension of an implanted lead during a staged (tined lead) evaluation for SNM. The system collected SER recordings across a range of prespecified stimulation settings (electrode configuration combinations for bipolar stimulation and bipolar sensing) during intraoperative and postoperative sessions in 21 subjects with overactive bladder (OAB) and nonobstructive urinary retention (NOUR). Motor and sensory thresholds were collected during the same sessions. ResultsSERs were detected in all 21 subjects. SER morphology (number of peaks, magnitude, and timing) varied across electrode configurations within and across subjects. Among subjects and electrode configurations tested, recordings contained SERs at motor threshold and/or sensory threshold in 75% to 80% of subjects. ConclusionsThis study confirmed that implanted SNM leads can be used to directly record SERs elicited by stimulation in subjects with OAB and NOUR. SERs were readily detectable at typical SNM stimulation settings and procedural time points. Using these SERs as possible objective measures of SNM response has the capability to automate patient-specific SNM therapy, potentially providing consistent lead placement, programming, and/or closed-loop therapy.

Design, implementation and assessment of a novel, introductory curriculum into female, neurological and urodynamic urology: a 7-year experience of urology simulation bootcamp course.

To present the seven-year experience of a multi-component and interactive module on female, neurological and urodynamic urology (FNUU) training at the UK National Urology Simulation Bootcamp Course (USBC) and demonstrate trainee satisfaction and competency progression. During the week-long USBC, a four-hour module on FNUU was designed which consisted of short interactive presentations with an emphasis on practical stations in urodynamics, intravesical botulinum toxin injection, urethral bulking injection, female pelvic examination and, initially, mid-urethral tapes (subsequently replaced with percutaneous sacral nerve evaluation). The trainee's level of knowledge, operative experience and confidence were assessed pre- and post-course. The practical assessment consisted of preparation and intravesical administration of botulinum toxin, female pelvic examination, urodynamic trace interpretation or mid-urethral tape simulation. Trainee feedback was also collected. Two-hundred sixty-one newly appointed urology trainees participated in the USBC during this period. A high level of satisfaction was constantly reported. The highest rated session was urethral bulking with 72% being very satisfied, followed by Botox and urodynamics. The final assessment showed 70% had achieved level 4 competency in cystoscopy and Botox. Qualitative feedback was also obtained. To our knowledge, this is the first module of its kind, and it shows that it is feasible to develop, implement and evaluate an introductory curriculum into FNUU that is reproducible over a 7-year period with very positive feedback.

A Multielectrode Nerve Cuff for Chronic Velocity Selective Recording in a sheep model.

Supra-sacral spinal cord injury (SCI) causes loss of bladder fullness sensation and bladder over-activity, leading to retention and incontinence respectively. Velocity selective recording (VSR) of nerve roots innervating the bladder might enable identification of bladder activity. A 10-electrode nerve cuff for sacral nerve root VSR was developed and tested in a sheep model during acute surgeries and chronic implantation for 6 months. The cuff performed well, with 5.90±1.90 kΩ electrode, and <~800 Ω tissue impedance after 189 days implantation with a stable device and tissues. This is important information for assessing the feasibility of chronic VSR.Clinical Relevance-This demonstrates the manufacturing and performance of a neural interface for chronic monitoring of bladder nerve afferents with applications in urinary incontinence and retention management following SCI.

Evaluation of a compact 3 T MRI scanner for patients with implanted devices

Access to high-quality MR exams is severely limited for patients with some implanted devices due to labeled MR safety conditions, but small-bore systems can overcome this limitation. For example, a compact 3 T MR scanner (C3T) with high-performance gradients can acquire exams of the head, extremities, and infants. Because of its reduced bore size and the patient being advanced only partially into the bore, the associated electromagnetic (EM) fields drop off rapidly caudal to the head, compared to whole-body systems. Therefore, some patients with MR conditional implanted devices can safely receive 3 T brain exams on the C3T using its strong gradients and a multiple-channel receive coil, while a corresponding exam on whole-body MR is precluded. The purpose of this study is to evaluate the performance of a small-bore scanner for subjects with MR conditional spinal or sacral nerve stimulators, or abandoned cardiac implantable electronic device (CIED) leads. The spatial dependence of specific absorption rate (SAR) on the C3T was compared to whole-body scanners. A device assessment tool was developed and applied to evaluate MR safety individually on the C3T for 12 subjects with implanted devices or abandoned CIED leads. Once MR safety was established, the subjects received a C3T brain exam along with their clinical, 1.5 T exam. The resulting images were graded by three board-certified neuroradiologists. The C3T exams were well-tolerated with no adverse events, and significantly outperformed the whole-body 1.5 T exams in terms of overall image quality.

The Use of Sphinkeeper® In Faecal Incontinence

Introduction: Faecal Incontinence is a condition that can affect up to 20% of population during their lifetime with female predominance. Sacral Nerve Stimulation (SNS) has been recently shown to have significant benefits in mainly urge incontinence but this has left a large group of patients with passive incontinence without effective management options. The SphinKeeper® (SK) allows treatment of more sizeable defects in the internal or external anal sphincter. Preliminary series have shown some benefit of the procedure in treatment of faecal incontinence. Methods: A single-centre retrospective observational study of SphinKeeper® prostheses was conducted at St Helens and Knowsley NHS trust and we believe this to be one of the largest series of SphinKeeper® in the UK. SphinKeeper® restores sphincter function by using placement of self-expanding prostheses into the inter-sphincteric space. The operation involves implantation of 10 self-expanding sterile prostheses between the internal and the external sphincter, thus creating a third ring around the circumference of the anal canal. Results: Most patients were ASA 2 (n=10). 43% (6/14) patients had previous colorectal surgery – THD and mucopexy (n=3), anorectal fistula surgery (n=1), anterior resection of rectum (n=1) and pelvic floor repair (n=1). EUS was carried out in 6 patients and in all 6 cases identified internal or external anal sphincter defect (IAS n=1, EAS n=3, IAS and EAS n=2). No patient sustained intraoperative complications. 2 patients reattended within 48 hours post op due to severe post-operative pain and were discharged with analgesia. Subjective results were evaluated using Vaizey and Wexner scores and showed significant improvement 4/14 patients, partial improvement in 7/14 patients and no improvement in 3/14 patients. Discussion: Our study evaluated the short-term outcomes of the procedure in 14 patients who had SphinKeeper® surgery between May 2017 and August 2020. Patients who took part in our study had previous treatment for faecal incontinence by a variety of methods (both medical and surgical) and suffered from different types of FI (passive, urge, mixed, associated urinary incontinence). It was promising to see there was a clinically significant improvement in continence indicated by a decrease in Vaizey and Wexner scores (p=0.00377 and p=0.00334 respectively (Wilcoxon test)) with 11 patients improving in scores. It is reasonable to consider Sphinkeeper™ as a safe and minimally invasive surgical intervention to achieve some degree of positive improvement for patients suffering from faecal incontinence.