Sacral nerve stimulation for neuromodulation of the lower urinary tract

Thoracic and abdominal devices radiologists should recognize: pictorial review

OBJECTIVE

Surgical, interventional, and diagnostic devices are continually being developed and often have unexpected radiographic appearances. The purpose of this article is to familiarize the radiologist with several devices that may be placed in the thorax and abdomen.

CONCLUSION

The radiologist's familiarity with the radiographic appearance of devices placed in the chest and abdomen is essential for accurate image interpretation and identification of postprocedure complications.

Interstitial cystitis: an unsolved enigma

Painful bladder syndrome/interstitial cystitis (PBS/IC) is a chronic disease of unknown etiology characterized by vague bladder pain and nonspecific urinary symptoms, such as urgency and frequency. Although it was initially considered to be a rare condition, its prevalence has significantly increased, possibly because of different definitions used and greater physician awareness. Because of the multiple diagnostic criteria used, there is significant variation in its prevalence. In addition, there is often a delay in the diagnosis of PBS/IC. It affects predominantly women of middle age, and it significantly decreases quality of life. Diagnosis of PBS/IC is mainly a diagnosis of exclusion; there are no characteristic symptoms or pathognomonic findings. Therefore, it is important to rule out diseases that have a similar clinical picture (i.e., urinary infections, bladder carcinoma) but definite therapies and worse prognosis if left untreated. PBS/IC management suffers from lack of evidence; many therapies are empiric or based on small studies and case series. Treatment includes supportive therapies (psychosocial, behavioral, physical), oral treatments, and intravesical treatments, whereas other more invasive treatments such as electric neuromodulation and reconstructive surgery are reserved for refractory cases. Physicians should always keep in mind the diagnosis of PBS/IC in patients presenting with chronic urinary symptoms after excluding other more common diseases.

Sacral neuromodulation for the treatment of chronic functional anorectal pain: a single center experience

INTRODUCTION

Treatment of functional anorectal pain disorders remains a challenge. The purpose of this study is to describe a single center experience with sacral neuromodulation for the treatment of chronic functional anorectal pain.

METHODS

This is a retrospective study based on prospectively collected data of patients treated with sacral neuromodulation for functional anorectal pain from April 2005 to August 2008. Symptoms were analyzed using a visual analog scale pain score (0 to 10). A 7-point Likert scale was used to rate global perceived effect. All patients had a percutaneous nerve evaluation and subsequent test stimulation to assess sacral neuromodulation outcome prior to permanent implantation. Patients were eligible for permanent sacral neuromodulation in case of a pain score <3 during test stimulation and/or >50% decrease in the pain score compared to baseline.

RESULTS

Nine patients (2 males) were included in this study. Mean age was 53.8 years (27.6 to 74.0). Four patients (1 male) had successful test stimulation and were eligible for permanent implantation. Median pain score decreased from 8.0 (6.0 to 9.0) to 1.0 (0 to 2.0). All patients experienced a lasting improvement during the follow-up till 24 months. Global perceived effect in successful patient was 1 (completely recovered) in one patient and 2 (much improved) in three patients.

CONCLUSION

This study showed that sacral neuromodulation can be a successful treatment for functional anorectal pain not responding to other treatments. Improvement obtained during test stimulation is a good predictor (diagnostic) for sustained success of permanent sacral neuromodulation.

Complex pelvic floor failure and associated problems

The pelvic floor is a highly complex structure made up of skeletal and striated muscles, support and suspensory ligaments, fascial coverings and an intricate neural network. Its dual role is to provide support for the pelvic viscera (bladder, bowel and uterus) and maintain functional integrity of these organs. In order to maintain good pelvic floor function, this elaborate system must work in a highly integrated manner. When this system if damaged, pelvic floor failure ensues. The aetiology is inevitably multi-factorial, and seldom as a consequence of a single aetiological factor. It can affect one or all the three compartments of the pelvic floor, often resulting in prolapse and functional disturbance of the bladder (urinary incontinence and voiding dysfunction), rectum (faecal incontinence), vagina and/or uterus (sexual dysfunction). This compartmentalisation of the pelvic floor has resulted in the partitioning of patients into urology, colo-rectal surgery or gynaecology, respectively, depending on the patients presenting symptoms. In complete pelvic floor failure, all three compartments are inevitably damaged resulting in apical prolapse, with associated organ dysfunction. It is clear that in this state, the patient needs the clinical input of at least two of the three pelvic floor clinical specialities. Whilst the primary clinical aim is to correct the anatomy, it must also be to preserve or restore pelvic floor function. As a consequence, these patients need careful clinical assessment, appropriate investigations, and counselling before embarking on a well-defined management pathway. The latter includes behavioural and lifestyle changes, conservative treatments (pelvic support pessaries, physiotherapy and biofeedback), pharmacotherapy, minimally invasive surgery (intravaginal slingoplasty, sacrospinous fixation and mid-urethral tapes) and radical specialised surgery (open or laparoscopic sacrocolpopexy). It is not surprising that in this complex group of patients, a multi-disciplinary approach is not only essential, but also critical, if good clinical care and governance is to be ensured.

Neuromodulation for functional bowel disorders

In patients with functional bowel disorders not responding to maximal medical treatment, bowel lavage or biofeedback therapy, can nowadays be treated by sacral nerve neuromodulation (SNM). SNM therapy has evolved as a treatment for faecal incontinence and constipation. The exact working mechanism remains unknown. It is known that SNM therapy causes direct stimulation of the anal sphincter and causes changes in rectal sensation and several central nervous system areas. The advantage of SNM therapy is the ability to do a minimally invasive temporary screening phase to assess permanent stimulation outcome. Ideal candidates for SNM therapy are not known. Several studies have described positive and negative predictive factors, but the temporary screening remains the instrument of choice. Clinical results are good and as the technique is developing, fewer complications occur. New indications for SNM include constipation and anorectal or pelvic pain.

Sacral neuromodulation with implanted devices for urinary storage and voiding dysfunction in adults

BACKGROUND

The neural control of storage and voiding of urine is complex and dysfunction can be difficult to treat. One treatment for people with refractory symptoms is continuous electrical nerve stimulation of the sacral nerve roots using implanted electrodes and an implanted pulse generator.

OBJECTIVES

To determine the effects of implantable electrical stimulation devices in the treatment of urine storage and voiding problems.

SEARCH STRATEGY

We searched the Cochrane Incontinence Group Specialised Register (searched 10 February 2009), CENTRAL (The Cochrane Library 2008, Issue 1), MEDLINE (January 1980 to March 2008), EMBASE (January 1980 to March 2008), CINAHL (January 1982 to March 2008) and the reference lists of relevant articles.

SELECTION CRITERIA

Trials that tested implanted electronic stimulators connected to electrodes attached to the nerves and providing continuous electrical stimulation for neuromodulation.

DATA COLLECTION AND ANALYSIS

Both authors selected studies, assessed quality, and extracted data.

MAIN RESULTS

Eight reports of randomised studies that evaluated implants which provided continuous stimulation were included. It was unclear whether some reports included patients who also appeared in other reports, so no data were pooled. In spite of this, it seems clear that continuous stimulation offers benefits for carefully selected people with overactive bladder syndrome and for those with urinary retention but no structural obstruction.Many of the implants did not work and many required revision operations. Many questions remain about patient selection and the best way to use these devices.

AUTHORS' CONCLUSIONS

In spite of methodological problems, it would appear that some people benefit from implants which provide continuous nerve stimulation. More research is needed on the best way to improve patient selection, carry out the implant, and to find why so many fail. The effectiveness of implants should be tested against other interventions, particularly in people with an overactive bladder.

Neuromodulation for the treatment of urinary incontinence

Neuromodulation has been reported to be effective for the treatment of stress and urgency urinary incontinence. The cure and improvement rates of pelvic floor neuromodulation in urinary incontinence are 30-50% and 60-90%, respectively. In clinical practice, vaginal, anal and surface electrodes are used for external, short-term stimulation, and sacral nerve stimulation for internal, chronic (long-term) stimulation. The effectiveness of neuromodulation has been verified in a randomized, placebo-controlled study. However, the superiority to other conservative treatments, such as pelvic floor muscle training has not been confirmed. A long-term effect has also been reported. In conclusion, pelvic floor exercise with adjunctive neuromodulation is the mainstay of conservative management for the treatment of stress incontinence. For urgency and mixed stress plus urgency incontinence, neuromodulation may therefore be the treatment of choice as an alternative to drug therapy.

Peripheral nerve stimulation for neuropathic pain

Peripheral nerve stimulation (PNS) has been used for treatment of neuropathic pain for more than 40 years. Recent resurgence of interest to this elegant surgical modality came from the introduction of less invasive implantation techniques and the wider acceptance of neuromodulation as a treatment of medically refractory cases. This article reviews the literature on the use of PNS for neuropathic pain and describes current indications and hardware choices in frequent use. Published experience indicates that neuropathic pain responds to PNS in many patients. PNS works well in both established indications, such as post-traumatic and postsurgical neuropathy, occipital neuralgia, and complex regional pain syndromes, and in relatively new indications for neuromodulation, such as migraines and daily headaches, cluster headaches, and fibromyalgia. Future research and growing clinical experience will help in identifying the best candidates for PNS, choosing the best procedure and best hardware for each individual patient, and defining adequate expectations for patients and pain specialists.