Minor microbial alterations after faecal diversion do not affect the healing process of anus-near pressure ulcers in patients with spinal cord injury - results of a matched case-control study.

Abstract Background: Pressure ulcers are a common complication in patients with spinal cord injury. The role of faecal diversion to support anus-near ulcer healing is under debate and its impact on the microbial colonisation pattern is unclear. The aim was to evaluate the primary microbial colonisation and secondary infection depending on the presence of a pre-existing diverting stoma and investigate the effect on the wound healing. Methods: A total of 120 spinal cord injured patients who had undergone surgery of an anus-near decubitus stage 3 or 4 were included in a retrospective matched-pair cohort study. Matching was realised according to age, gender, body mass index and general condition. Results: The most common species in both groups was Staphylococcus aureus (45.0 %). The only significantly different primary colonisation affected Escherichia coli, that was found in the stoma patients less often (18.3 and 43.3 %, p < 0.01). A secondary microbial colonisation occurred in 15.8 % and was equally distributed, except for Enterococcus spp. that was present only in the stoma group (6.7 %, p < 0.05). The time to complete cure took longer in the stoma group (78.5 versus 57.0 days, p < 0.05) and was associated with a larger ulcer size (25 versus 16 cm2, p < 0.01). After correction for the ulcers’ size, there was no association to outcome parameters such as overall success, healing time or adverse events. Conclusion: The presence of a diverting stoma alters the microbial flora of an anus-near decubitus slightly without impact on the healing process.