A randomized trial comparing transanal irrigation and percutaneous tibial nerve stimulation in the management of low anterior resection syndrome

Aim To assess the effectiveness of transanal irrigation (TAI) compared with posterior tibial nerve stimulation (PTNS) in severe and chronic low anterior resection syndrome (LARS). Method A two-group parallel, open-label randomized controlled trial carried out in a single university hospital. The study population included patients with a LARS scale score of more than 29 points who had undergone rectal surgery more than 1 year previously. These were randomly allocated, with a central randomization system, following a 1:1 sequence to TAI or PTNS. The main study outcome was to achieve a reduction of at least one LARS grade in at least 50% of the patients, for each intervention. Results A total of 27 patients (TAI = 13, PTNS = 14) were randomized. Both groups were similar with regard to confounding factors. Four patients were excluded because of intercurrent disease or early dropout, leaving 23 (TAI, n = 10; PTNS, n = 13) for analysis. Eight out of 10 and 4 out of 13 patients were downgraded with TAI and PTNS, respectively. The median LARS score decreased from 35 [interquartile range (IQR) 32-39] to 12 (IQR 12-26) (P = 0.021) for the TAI group and from 35 (IQR 34-37) to 30 (IQR 25-33) (P = 0.045) for the PTNS group. The Vaizey score fell from 15 (IQR 11-18) to 6 (IQR 4-7) (P = 0.037) and from 14 (IQR 13-17) to 9 (IQR 7-10) (P = 0.007) with TAI and PTNS, respectively, with 80% and 38% of patients, respectively, showing decreases of more than 50%. Improvement in quality of life was observed in both groups. Conclusion Both treatments improved the LARS score in this study but this was only significant in the TAI group.