Factors Associated With Efficacy of Percutaneous Tibial Nerve Stimulation for Fecal Incontinence, Based on Post-Hoc Analysis of Data From a Randomized Trial.

BACKGROUND & AIMS: A recent randomized, multi-center, phase 3 trial, performed in the United Kingdom (Control of Fecal Incontinence using Distal Neuromodulation Trial), demonstrated no significant clinical benefit of percutaneous tibial nerve stimulation (PTNS) compared to sham stimulation in patients with fecal incontinence (FI). However, this study did not analyze predictors of response. We used data from this trial to identify factors that predict the efficacy of PTNS in adults with FI. METHODS: The study population comprised 205 patients from the CONtrol of Fecal Incontinence using Distal NeuromodulaTion Trial. The primary outcome was a binary indicator of success (≥50% reduction in weekly FI episodes after 12 weeks of treatment) or failure, as per the original trial characteristics including baseline FI symptom type, defecatory urgency, and co-existent symptoms of baseline liquid stool consistency and obstructive defecation (OD) were defined a priori. Univariable and multivariable analyses were performed to explore these factors as predictors of response to PTNS and sham. RESULTS: In both univariable and multivariable analysis, the presence of OD symptoms negatively predicted outcome in patients who received PTNS (OR, 0.38; 95% CI, 0.16-0.91; P = .029), and positively predicted sham response (OR, 3.45; 95% CI, 1.31-9.21; P = .012). No other tested variable affected outcome. Re-analysis of the primary outcome excluding patients with OD symptoms (n = 112) resulted in a significant clinical effect of PTNS compared to sham (48.9% vs 18.2% response, P = .002; multivariable OR, 4.71; 95% CI, 1.71-12.93; P = .003). CONCLUSIONS: Concomitant OD symptoms negatively affected the clinical outcome of PTNS vs sham in a major randomized controlled trial. Future appropriately designed studies could further explore this observation with potential for future stratified patient selection.

Diagnostic accuracy study of anorectal manometry for diagnosis of dyssynergic defecation.

OBJECTIVE: The diagnostic accuracy of anorectal manometry (AM), which is necessary to diagnose functional defecatory disorders (FDD), is unknown. Using blinded analysis and standardised reporting of diagnostic accuracy, we evaluated whether AM could discriminate between asymptomatic controls and patients with functional constipation (FC). DESIGN: Derived line plots of anorectal pressure profiles during simulated defecation were independently analysed in random order by three expert observers blinded to health status in 85 women with FC and 85 age-matched asymptomatic healthy volunteers (HV). Using accepted criteria, these pressure profiles were characterised as normal (ie, increased rectal pressure coordinated with anal relaxation) or types I-IV dyssynergia. Interobserver agreement and diagnostic accuracy were determined. RESULTS: Blinded consensus-based assessment disclosed a normal pattern in 16/170 (9%) of all participants and only 11/85 (13%) HV. The combined frequency of dyssynergic patterns (I-IV) was very similar in FC (80/85 (94%)) and HV (74/85 (87%)). Type I dyssynergia ('paradoxical' contraction) was less prevalent in FC (17/85 (20%) than in HV (31/85 (36.5%), p=0.03). After statistical correction, only type IV dyssynergia was moderately useful for discriminating between FC (39/85 (46%)) and HV (17/85 (20%)) (p=0.001, positive predictive value=70.0%, positive likelihood ratio=2.3). Interobserver agreement was substantial or moderate for identifying a normal pattern, dyssynergia types I and IV, and FDD, and fair for types II and III. CONCLUSIONS: While the interpretation of AM patterns is reproducible, nearly 90% of HV have a pattern that is currently regarded as 'abnormal' by AM. Hence, AM is of limited utility for distinguishing between FC and HV.

Double-blind randomised controlled trial of percutaneous tibial nerve stimulation versus sham electrical stimulation in the treatment of faecal incontinence: CONtrol of Faecal Incontinence using Distal NeuromodulaTion (the CONFIDeNT trial).

BACKGROUND: Faecal incontinence (FI) is a common condition which is often under-reported. It is distressing for those suffering from it, impacting heavily on their quality of life. When conservative strategies fail, treatment options are limited. Percutaneous tibial nerve stimulation (PTNS) is a minimally invasive outpatient treatment, shown in preliminary case series to have significant effectiveness; however, no randomised controlled trial has been conducted. OBJECTIVES: To assess the effectiveness of PTNS compared with sham electrical stimulation in the treatment of patients with FI in whom initial conservative strategies have failed. DESIGN: Multicentre, parallel-arm, double-blind randomised (1 : 1) controlled trial. SETTING: Eighteen UK centres providing specialist nurse-led (or equivalent) treatment for pelvic floor disorders. PARTICIPANTS: Participants aged > 18 years with FI who have failed conservative treatments and whose symptoms are sufficiently severe to merit further intervention. INTERVENTIONS: PTNS was delivered via the Urgent(®) PC device (Uroplasty Limited, Manchester, UK), a hand-held pulse generator unit, with single-use leads and fine-needle electrodes. The needle was inserted near the tibial nerve on the right leg adhering to the manufacturer's protocol (and specialist training). Treatment was for 30 minutes weekly for a duration of 12 treatments. Validated sham stimulation involved insertion of the Urgent PC needle subcutaneously at the same site with electrical stimulation delivered to the distal foot using transcutaneous electrical nerve stimulation. MAIN OUTCOME MEASURES: Outcome measures were assessed at baseline and 2 weeks following treatment. Clinical outcomes were derived from bowel diaries and validated, investigator-administered questionnaires. The primary outcome classified patients as responders or non-responders, with a responder defined as someone having achieved ≥ 50% reduction in weekly faecal incontinence episodes (FIEs). RESULTS: In total, 227 patients were randomised from 373 screened: 115 received PTNS and 112 received sham stimulation. There were 12 trial withdrawals: seven from the PTNS arm and five from the sham arm. Missing data were multiply imputed. For the primary outcome, the proportion of patients achieving a ≥ 50% reduction in weekly FIEs was similar in both arms: 39 in the PTNS arm (38%) compared with 32 in the sham arm (31%) [odds ratio 1.28, 95% confidence interval (CI) 0.72 to 2.28; p = 0.396]. For the secondary outcomes, significantly greater decreases in weekly FIEs were observed in the PTNS arm than in the sham arm (beta -2.3, 95% CI -4.2 to -0.3; p = 0.02), comprising a reduction in urge FIEs (p = 0.02) rather than passive FIEs (p = 0.23). No significant differences were found in the St Mark's Continence Score or any quality-of-life measures. No serious adverse events related to treatment were reported. CONCLUSIONS: PTNS did not show significant clinical benefit over sham electrical stimulation in the treatment of FI based on number of patients who received at least a 50% reduction in weekly FIE. It would be difficult to recommend this therapy for the patient population studied. Further research will concentrate on particular subgroups of patients, for example those with pure urge FI. TRIAL REGISTRATION: Current Controlled Trials ISRCTN88559475. FUNDING: This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 19, No. 77. See the NIHR Journals Library website for further project information.

Percutaneous tibial nerve stimulation versus sham electrical stimulation for the treatment of faecal incontinence in adults (CONFIDeNT): a double-blind, multicentre, pragmatic, parallel-group, randomised controlled trial.

BACKGROUND: Percutaneous tibial nerve stimulation (PTNS) is a new ambulatory therapy for faecal incontinence. Data from case series suggest it has beneficial outcomes in 50-80% patients; however its effectiveness against sham electrical stimulation has not been investigated. We therefore aimed to assess the short-term efficacy of PTNS against sham electrical stimulation in adults with faecal incontinence. METHODS: We did a double-blind, multicentre, pragmatic, parallel-group, randomised controlled trial (CONtrol of Faecal Incontinence using Distal NeuromodulaTion [CONFIDeNT]) in 17 specialist hospital units in the UK that had the skills to manage patients with faecal incontinence. Eligible participants aged 18 years or older with substantial faecal incontinence for whom conservative treatments (such as dietary changes and pelvic floor exercises) had not worked, were randomly assigned (1:1) to receive either PTNS (via the Urgent PC neuromodulation system) or sham stimulation (via a transcutaneous electrical nerve stimulation machine to the lateral forefoot) once per week for 12 weeks. Randomisation was done with permuted block sizes of two, four, and six, and was stratified by sex and then by centre for women. Patients and outcome assessors were both masked to treatment allocation for the 14-week duration of the trial (but investigators giving the treatment were not masked). The primary outcome was a clinical response to treatment, which we defined as a 50% or greater reduction in episodes of faecal incontinence per week. We assessed this outcome after 12 treatment sessions, using data from patients' bowel diaries. Analysis was by intention to treat, and missing data were multiply imputed. This trial is registered with the ISRCTN registry, number 88559475, and is closed to new participants. FINDINGS: Between Jan 23, 2012, and Oct 31, 2013, we randomly assigned 227 eligible patients (of 373 screened) to receive either PTNS (n=115) or sham stimulation (n=112). 12 patients withdrew from the trial: seven from the PTNS group and five from the sham group (mainly because they could not commit to receiving treatment every week). Two patients (one in each group) withdrew because of an adverse event that was unrelated to treatment (exacerbation of fibromyalgia and rectal bleeding). 39 (38%) of 103 patients with full data from bowel diaries in the PTNS group had a 50% or greater reduction in the number of episodes of faecal incontinence per week compared with 32 (31%) of 102 patients in the sham group (adjusted odds ratio 1·28, 95% CI 0·72-2·28; p=0·396). No serious adverse events related to treatment were reported in the trial. Seven mild, related adverse events were reported in each treatment group, mainly pain at the needle site (four in PTNS, three in sham). INTERPRETATION: PTNS given for 12 weeks did not confer significant clinical benefit over sham electrical stimulation in the treatment of adults with faecal incontinence. Further studies are warranted to determine its efficacy in the long term, and in patient subgroups (ie, those with urgency). FUNDING: National Institute for Health Research.

Evaluation of a framework for case development and simulated patient training for complex procedures.

BACKGROUND: Simulation for training and assessing clinicians is increasing but often overlooks the patient's perspective. In this paper, actors are trained to portray patients undergoing operations under local anesthetic within a high-fidelity simulated operating theater (SOT). There are few published accounts of approaches to case development and simulated patient (SP) training. We assess the feasibility of SPs playing complex surgical roles and evaluate a three-phased framework for case development and SP training. METHODS: We developed two patient roles for carotid endarterectomy (CEA) under local anesthesia. In all cases, the conscious patient interacted with the surgical team throughout the procedure. SPs were trained to simulate routine and crisis situations, using our framework. After consulting with each SP, surgeons "performed" a CEA upon a model attached to the SP. Evaluation of the framework used interviews, observations, and written evaluations with SPs, surgeons, and the project team. Descriptive statistics summarize surgeons' ratings of realism and qualitative data are analyzed thematically. RESULTS: In all, 46 simulations were conducted with 23 surgeons and three SPs. Real patient interview transcripts provided SPs with authentic information. The SP framework was easy to use, SP training was successful and surgeons' rated SP realism very highly. SPs valued guidance from the SOT control room using an audiolink. CONCLUSIONS: Actors can be trained to portray patients undergoing complex procedures. Our framework for case development and SP training was effective in creating realistic roles. Future studies could evaluate this framework for additional procedures.