Hypothesis / aims of the study: This is the first efficacy study on an electronical transanal irrigation system used for patients with bowel dysfunction. Transanal irrigation (TAI) has emerged as a key option in management when conservative treatment options for bowel dysfunction do not help, but existing systems do not suit all patients. Navina Smart is a TAI system that consists of an electronic control unit, pump and smartphone app. The control unit permits more accurate monitoring of irrigation parameters with connection to the Navina Smart app, which may improve treatment adherence. The majority of individuals with spinal cord injury (SCI) experience moderate to severe symptoms related to neurogenic bowel dysfunction (NBD), e.g. faecal incontinence and constipation. There is a significant correlation between the severity of NBD and quality of life (QoL), especially with regards to physical functioning. In this study, NBD score has been used as primary endpoint correlating to NBD symptom severity and QoL. We present a partial clean file analysis of three months data from an open, prospective, multicentre study with the primary aim to evaluate change in NBD symptoms after three months use of Navina Smart.

Study design, materials and methods: Eighty-nine consecutive consenting patients (61 male; mean age 48, range 18-77) naïve to TAI treatment were recruited from ten centres in seven countries. Patients had experienced traumatic or non-traumatic SCI at least three months before baseline and had confirmed NBD of at least moderate severity (NBD score equal to or above 10). Subjects were taught how to use the device at baseline and treatment was tailored during phone calls until optimal TAI regime was achieved, using the Navina Smart app. The NBD score was measured at baseline and at three months follow up (mean 98 days) with completion of a questionnaire. Safety analysis was performed on the complete population while per protocol (PP) analysis was performed on 52 subjects (ASIA-A=22, -B=7, -C=8, -D=13, unknown=2).

Results: PP analysis showed a significant decrease in mean NBD score (17.8 to 10, p<0.00001) among all subjects. In subjects with severe symptoms (defined as NBD score equal to or above 14) specifically, NBD scores decreased (mean of 8.5) and from 41 (79%) subjects with severe symptoms at baseline to 16 (31%) subjects at three months follow-up. Device failure accounted for the commonest cause for loss of data. Side effects, collected as Adverse Events, that were judged as at least possibly related to the device developed in 11 subjects (12%) of the total 89 subjects: autonomic dysreflexia symptoms 3 (3%), faecal incontinence 2 (2%), urinary infection 2 (2%), anal pain or anal bleeding 2 (2%), abdominal pain 2 (2%). Discontinuation due to failure of the therapy to relieve symptoms was reported by 5 subjects (6%).

Interpretation of results: Navina Smart is an effective treatment for patients with NBD. This is seen even in patients with severe symptoms, with a 50% reduction of NBD score in patients with severe symptoms. Whilst there were some device problems (addressed by the later stages of subject recruitment) there was a low rate of Adverse Events at least possibly related to the device (12%), and no severe events identified.

Concluding message: From this first efficacy study on Navina Smart we conclude that Navina Smart is an effective treatment option for patients with NBD during the initial three months. The largest effect, in terms of decreased NBD score, was seen in patients with severe NBD symptoms where more than half of the subjects improved from severe NBD to very minor, minor or moderate NBD. Whilst there were some device related problems, the Navina Smart was well tolerated with only 12% of patients reporting adverse effects. Twelve months efficacy results will follow, including results on QoL and perception of Navina Smart.