An open prospective study on the efficacy of Navina Smart, an electronic system for transanal irrigation, in neurogenic bowel dysfunction

Abstract

Background: Transanal irrigation (TAI) has emerged as a key option when more conservative bowel management does not help spinal cord injured (SCI) individuals with neurogenic bowel dysfunction (NBD).

Aim: To investigate the short-term efficacy and safety of an electronic TAI system (Navina Smart) in subjects with NBD.

Design: We present an open, prospective efficacy study on Navina Smart, in individuals with NBD secondary to SCI, studied at three months.

Population: Eighty-nine consecutive consenting established SCI individuals (61 male; mean age 48, range 18-77) naïve to TAI treatment were recruited from ten centres in seven countries. Subjects had confirmed NBD of at least moderate severity (NBD score ≥10).

Methods: Subjects were taught how to use the device at baseline assisted by the Navina Smart app, and treatment was tailored during phone calls until optimal TAI regime was achieved. The NBD score was measured at baseline and at three months follow up (mean 98 days). Safety analysis was performed on the complete population while per protocol (PP) analysis was performed on 52 subjects.

Results: PP analysis showed a significant decrease in mean NBD score (17.8 to 10, p<0.00001). In subjects with severe symptoms (defined as NBD score ≥14), mean NBD scores decreased (19.4 to 10.9, p<0.0001). The number of subjects with severe symptoms decreased from 41 (79%) subjects at baseline to 16 (31%) at three months follow-up. Device failure accounted for the commonest cause for loss of data. Side effects possibly related to the device developed in 11 subjects (12%). Discontinuation due to failure of therapy to relieve symptoms was reported by 5 subjects (6%).

Conclusion: Navina Smart is effective for individuals with NBD, even those with severe symptoms; long-term data will follow. Whilst there were some device problems (addressed by the later stages of subject recruitment) the treatment was generally safe.

Clinical trial: (ClinicalTrials.gov number NCT02979808).

Conflict of interest statement

The study was fully sponsored by Wellspect Healthcare, some of the authors have consultancy agreements, have received honoraria for speaking and/or are members of advisory boards for Wellspect Healthcare and other companies within the area of transanal irrigation. This does not alter our adherence to PLOS ONE policies on sharing data and materials. Wellspect had no influence on the content of the manuscript, which was written by the authors.

Figures

Fig 1. Disposition of study subjects.

A total of 89 subjects were enrolled in the study while 84 started treatment and after 3 months 28 subjects were withdrawn (33% drop-out (28/84)). (n, number; AE/SAE, adverse event/serious adverse event; ITT, intention to treat; PP, per protocol, FU, follow up).

Fig 2. Change in NBD severity.

The were 41 subjects with severe NBD symptoms at baseline visit and after 3 months use of Navina Smart the number had decreased to 16 subjects with severe NBD symptoms. A third of the subjects had very minor NBD symptoms after 3 months in the study.

Fig 3. Correlation of NBD score and satisfaction with current bowel management.

Change in NBD score (x axis) after 3 months use was correlated with change in satisfaction with current bowel management (y axis) after 3 months use of TAI. The Spearman rank correlation coefficient was -0.46, p = 0.0006 between decreased NBD score and increased satisfaction with subjects’ bowel management.

Fig 4. Navina™ Smart system.

The Navina Smart system consists of a hydrophilic rectal catheter with an in-/deflatable balloon for retention, tubing, connectors, a water container, an electrical control unit and a smartphone/tablet app.

Fig 5. Cumulative Device Defiencies (DD) versus ongoing subjects.

The number of DD reports that occurred monthly added together with the number of ongoing subjects each month shows that the first version of the electronic control unit used in the study resulted in most DD reports while continuous product improvements and software updates once the problem was identified and rectified decreased the DD reports (Feb/March 2018 indicated by the arrow). None of the DD resulted in a safety event.