Buttock placement of the implantable pulse generator: a new implantation technique for sacral neuromodulation--a multicenter study

Efficacy and safety of sacral nerve stimulation for urinary urge incontinence: a systematic review

PURPOSE

We systematically reviewed the evidence on the efficacy and safety of sacral nerve stimulation (SNS) for severe urge incontinence.

MATERIALS AND METHODS

A systematic review was performed of primary studies of SNS for urge incontinence published in English between 1966 and May 2003, and identified in major electronic databases. Two reviewers independently selected studies, assessed their methodological quality and extracted data.

RESULTS

Four randomized controlled trials and 30 case series were identified. Evidence from the randomized controlled trials, involving approximately 120 patients, showed that about 80% achieved continence or greater than 50% improvement in their main incontinence symptoms after SNS compared with about 3% of controls receiving conservative treatments while waiting for an implant. While case series were larger, they were methodologically less reliable. However, they showed similar results with 67% of patients becoming dry or achieving a greater than 50% improvement in symptoms after implantation. Incontinence episodes, leakage severity, voiding frequency and pad use were significantly lower after implantation. Benefits were reported to persist 3 to 5 years after implantation. Adverse events were documented in 27 studies. Overall the reoperation rate in implanted cases was 33%. The most common reason for surgical revision was relocation of the generator because of pain and infection. Common complications were pain at the implant or lead site in 25% of patients, lead related problems such as lead migration in 16%, replacement and repositioning of the implanted pulse generator in 15%, wound problems in 7%, adverse effects on bowel function in 6%, infection in 5% and generator problems in 5%. Permanent removal of the electrodes was reported in 9% of patients. Technical changes with time have been associated with decreased complication rates.

CONCLUSIONS

There is evidence indicating that SNS is effective for decreasing symptoms in patients with urge incontinence. Adverse events occurred in about half of the implanted cases and surgical revision was performed in 33%. No major irreversible complications were reported in the studies reviewed. Further research is required on the long-term effects of and quality of life in patients with SNS.

Long Term Results of Neuromodulation by Sacral Nerve Stimulation for Lower Urinary Tract Symptoms: A Retrospective Single Center Study

OBJECTIVE

To analyse the influence of technical improvements of Sacral Nerve Stimulation (SNS) on the incidence of surgical interventions and subjective long-term results of SNS.

METHODS

Retrospective, transversal study analyzing records of implanted patients at our department of Urology.

RESULTS

Of 149 patients analyzed, 107 had overactive bladder symptoms and 42 had urinary retention. Mean follow-up was 64,2 (sd = 38,5) months. In the whole group 194 adverse events occurred. 6 Patients had infection in their implanted system, one was explanted for infection. Most events could be solved by giving advice or by reprogramming the stimulator. 129 reoperations have been performed and 21 patients had their system explanted. Analysis of the data shows a striking difference in the incidence of reoperations, but small differences in subjective results in the groups of patients implanted before or after 1996, suggesting that a proactive approach towards adverse events is worthwhile.

CONCLUSIONS

SNS gives lasting benefit in patients with refractory symptoms of overactive bladder and non-obstructive urinary retention. The differences in outcomes and incidence of reoperation can be attributed to the learning curve and technical and surgical improvements in the application of SNS.

New tined lead electrode in sacral neuromodulation: experience from a multicentre European study

The use of a new tined lead electrode for sacral neuromodulation (SNS) was evaluated in a European study including 127 patients with chronic voiding dysfunction. The tined lead can be implanted during the first stage of the SNS procedure, which makes a longer test period possible before implanting the pulse generator in a second stage. Implantation of the tined lead was performed under local anaesthesia in 89% of patients. Screening lasted on average 30 days. Screening with the tined lead was considered successful by the physicians in 77% of patients (n=72). In 74% of first stage patients (n=70), at least 50% improvement in the main symptoms versus baseline was obtained. This was sustained for up to 6 weeks. All of these patients received the pulse generator in a second stage. The outcome of this study supports the use of the tined lead electrode as a screening tool in SNS therapy.

Sacral nerve stimulation: an emerging treatment for faecal incontinence

Faecal incontinence is common, distressing to the patient and socially incapacitating. The treatment options depend on the severity and aetiology of incontinence. For mild cases of faecal incontinence, medical management and pelvic floor physiotherapy may be adequate. For more severe cases, surgery is often required. Patients who have a distinct sphincter defect are amenable to surgical repair. In many cases, there is a combination of diffuse structural damage of the anal sphincters with pudendal neuropathy. Conventional surgical repairs have a modest degree of success and the results tend to deteriorate with time. Neosphincter procedures such as artificial bowel sphincter and dynamic graciloplasty are potentially morbid and technically complex. Sacral nerve stimulation is innovative and has had a medium-term success with improvement of quality of life in over 80% of patients treated for faecal incontinence. These results are superior to other techniques in treating patients with severe refractory faecal incontinence, where current maximal therapy has failed. The technique is unique because there is a screening phase, which has a high predictive value. It is also associated with minimal complications that are usually minor. However, most published reports of sacral nerve stimulation for treatment of faecal incontinence were case studies and methods of assessing outcome were variable. Criteria for patient selection are evolving and are yet to be defined. The present paper critically reviews the publications to date on sacral nerve stimulation for treatment of faecal incontinence. This will form the basis for future evaluation of this emerging treatment of severe, intractable faecal incontinence. Randomized clinical trials like that of the Melbourne trial will further clarify the role and indications of sacral nerve stimulation for faecal incontinence.

Surgical techniques of sacral implantation

Refinements in making surgical approaches in sacral neurostimulation less morbid and more efficient has resulted in this approach being a tenable option for those patients afflicted with idiopathic urinary urge incontinence, frequency-urgency syndrome, and nonobstructive urinary retention. Traditionally, these patients were relegated to suffering with their bladder symptoms because of the lack of options. Now, this form of therapy, although not perfect, offers hope to many. Future refinements in treatment of these patients will be multifaceted including further improvements in surgical approaches, under-standing pathophysiology, and better diagnostic tools.

Innovations in fecal incontinence: sacral nerve stimulation

OBJECTIVE

The aim of this study was to present an overview of sacral nerve stimulation in the treatment of fecal incontinence. We describe the evolution in technique, patient selection, and indications, and review results and complications.

METHODS

All articles on sacral nerve stimulation for fecal incontinence that were recovered on MEDLINE search were reviewed. With multiple articles from an institution, the most recent reports with the longest follow-up and largest cohort of patients were selected, unless information from earlier reports was relevant.

RESULTS

The technique of sacral stimulation is well established, carries little risk, and continues to be refined (e.g., a less invasive approach has been proposed). Patient selection is based on a two-stage diagnostic test stimulation (acute and subchronic), for which the predictive value is high. On this basis, permanent sacral nerve stimulation has proved effective in both single-center and multicenter trials in patients with a functional deficit but limited morphologic lesions or no morphologic lesions. The clinical benefit derives from multiple symptomatic improvements contributing to better bowel control and from substantially improved quality of life. The underlying mechanism of action remains undefined, but both somatic and autonomic function appears affected.

CONCLUSION

Sacral nerve stimulation offers a safe treatment mode in a patient population in whom conservative treatment has failed and traditional surgical approaches would have limited success. The high predictive value of the diagnostic approach offers a unique therapeutic advantage.

Long-term results of sacral neuromodulation for women with urinary retention

OBJECTIVE ; To review the long-term results of sacral nerve stimulation in the treatment of women with Fowler's syndrome, over a 6-year period at one tertiary referral centre.

PATIENTS AND METHODS

Between 1996 and 2002, 26 women with urinary retention were treated by implanting a sacral nerve stimulator. Their case records were reviewed for follow-up, complications and revision procedures, and the most recent uroflowmetry results.

RESULTS

There were 20 patients (77%) still voiding spontaneously at the time of review (with two having deactivated their stimulator because of pregnancy). Fourteen patients (54%) required revision surgery, and the most common complications included loss of efficacy, implant-related discomfort and leg pain. The mean postvoid residual volume was 75 mL and mean maximum flow rate 20.8 mL/s.

CONCLUSION

In young women with retention, for whom there is still no alternative to lifelong self-catheterization, sacral neuromodulation is effective for up to 5 years after implantation. However, there was a significant complication rate, in line with other reports, which may be improved by new technical developments.

THE USE OF ELECTRICAL DEVICES FOR THE TREATMENT OF BLADDER DYSFUNCTION: A REVIEW OF METHODS

PURPOSE

We reviewed the literature on the application of various devices and techniques for the electrical stimulation treatment of lower urinary tract dysfunction with respect to mechanism of action and clinical outcome.

MATERIALS AND METHODS

A systematic review was done in PubMed of publications on intravesical stimulation, direct bladder stimulation, stimulation of the pelvic and pudendal nerves, transcutaneous-electrical nerve stimulation, stimulation of the sacral spine and roots, and lower limb stimulation.

RESULTS

It is difficult truly to compare different treatment modalities because there are hardly any randomized placebo controlled studies. Also, there is considerable variety in treatment parameters and schedules reported as well as in criteria for success. Nevertheless, it can be said that electrical neurostimulation and neuromodulation result in a 30% to 50% clinical success on an intent to treat basis. Influencing lower urinary tract innervation at the level of sacral roots seems successful in neurological and nonneurological cases. It has the advantage of pretesting possibilities to improve patient selection and treatment outcome with the obvious drawback of invasiveness. Noninvasive techniques lack screening tests, making patient selection a matter of trial and error, and when there is success patients almost always need maintenance therapy.

CONCLUSIONS

Randomized clinical trials to compare different techniques and evaluate placebo effects are urgently needed, as are further studies to elucidate modes of action to improve stimulation application and therapy results. The introduction of new stimulation methods may provide treatment alternatives as well as help answer more basic questions on electrical neurostimulation and neuromodulation.

A Prospective Randomized Trial Comparing the 1-Stage with the 2-Stage Implantation of a Pulse Generator in Patients with Pelvic Floor Dysfunction Selected for Sacral Nerve Stimulation

OBJECTIVE

The aim of this study was to evaluate in a prospective, randomized setting if the 2-stage implant, compared to a 1-stage implant, leads to a superior subjective or objective outcome of sacral nerve stimulation after implantation of the pulse generator in patients with lower urinary tract symptoms.

PATIENTS AND METHODS

We implanted a sacral (S3) foramen lead and a pulse generator (model 3023, Medtronic Inc, Minneapolis, MN, USA) in 42 patients. They were randomized in a 1-stage or a 2-stage implant if a more than 50% improvement in voided volume or reduction of residual urine was seen during the test stimulation phase as compared to baseline.

RESULTS

At 24 months follow-up, subjective (visual analogue scale) and objective (voided volume or residual urine) assessment were significantly better in the 2-stage group. Ten patients (24%) failed therapy, 7 in the 1-stage implant and 3 in the 2-stage group. Two patients were lost to follow-up. Logistic regression analysis revealed that failure was positively related to the 1-stage implant and negatively to the age of the patients. 76% of the treated patients had sustained clinical benefit with 23 revisions performed. The mean cost is respectively for the PNE (2006 Euro), for the 2-stage implant (10826 Euro) and for the 1 stage implant (8505 Euro).

CONCLUSION

With this study, we demonstrated that the 2-stage implantation technique of the sacral neuromodulation therapy performed as a longer test stimulation phase has a higher success rate.

Sacral neuromodulation in Norway: clinical experience of the first three years

We present our first three years' experience of sacral neromodulation as first line therapy in patients with a non-neurogenic refractory urge incontinence. In 53 patients, 45 women and 8 men with a mean age of 54 years (range 17-76 years), tested by subacute percutan nerve evaluation, 19 patients were declared as responders according to our programme. Fourteen patients, twelve women and two men with a mean age of 47 years (range 33-73 years), agreed to implantation of a neuroprosthesis (Medtronic Interstim Model 3031), which was placed in a subcutaneous buttock pocket in 12 patients. In the first two patients, the device was implanted subcutaneously corresponding to the lower quadrants of the abdominal wall. In two patients, the lead was repositioned from S:4 to S:3 six to twelve months after the primary implantation. In one woman with sensory urgency, the neuroprosthesis was removed six months after it was implanted because of failure. The patients were followed every six months using voiding diary, uroflowmetry, residual urine and cystometry. Eight patients reported total continence, and five declared >50% improvement. One woman has chronic bacteriuria and intermittently symptomatic urinary tract infection, which reduce the response to the chronic sacral nerve stimulation. Because of residual urine, four women are following an individual self-catheterisation programme. In conclusion, we have documented that sacral neuromodulation is an effective and safe procedure in patients with refractory urge incontinence depending on detrusor overactivity. We confirm the clinical results reported by other centres with long experience of sacral neuromodulation.

A simplified method of implanting a neuromodulator device

PURPOSE

The InterStim neuromodulator device (Medtronic, Inc., Minneapolis, Minnesota) is indicated for the treatment of refractory urge incontinence, urinary frequency and urgency, and nonobstructive urinary retention. We present a modification of the 2-stage approach which is simple to perform, reduces the number of incisions from 2 to 1, decreases operative time and potentially decreases the risk of infection.

MATERIALS AND METHODS

Using a single paramedian incision, a quadripolar lead is placed into the appropriate sacral foramen. The lead is connected to the extension wire and the connector is anchored into an ipsilateral subcutaneous tunnel with the aid of an externalized polypropylene suture and plastic button. The extension wire is then externalized through the contralateral buttock using a subcutaneous tunneling device. At stage 2 the entire system can be removed through the original incision or the pulse generator can be implanted through a virgin incision over the connector site.

RESULTS

A total of 20 procedures have been performed with an average stage 1 implant time of 72 minutes. Median implant time of 13 pulse generators was 36 minutes. Median explant time of 6 leads was 21 minutes. There have been no infections or adverse events.

CONCLUSIONS

This modification is simple, efficient, safe and involves use of tools already familiar to urologists. By reducing the number of incisions, it reduces violation of the skin barrier and consequently risk of infection. Infection is potentially reduced at stage 2 because there is undisturbed, noncontused virgin tissue at the site of generator implant.