Eligibility criteria included: full text papers, presence of diabetes type 1 and 2, and different preparation of amniotic allografts (dehydrated, cryopreserved and stem cell extractions). RCTs comparing amniotic membrane versus standard or conventional care were included. Studies designed with the aim of analysing the molecular basis without measuring clinical improvement of the ulcers were excluded, as were case studies. Data were extracted on trial design, study setting, amniotic membrane preparation methods used, control interventions, outcome measures and statistical analysis. Outcome measure data regarding healing time, percentage healed, recurrences and adverse outcomes were extracted.
From 64 identified studies, only 12 met the inclusion criteria. Of these, eight were RCTs (5 multicentre) involving 454 patients (244 amnion, 210 control) with a mean ulcer size 5 cm2, two were prospective studies (28 amnion treated) and two were retrospective studies (92 amnion treated) with a mean ulcer size ≥5 cm2. All these studies except one (from Spain) were conducted in the USA. The DFU locations were varied with a mean duration of >28 days. The mean healing times for the amnion groups was very varied but significantly faster ranging from 3 to 26 weeks compared with the control groups.
In six RCTs, the follow-up duration was 12 weeks, while in the other two, it was 6 weeks. The prospective and retrospective studies included data until complete wound closure was achieved.
Just two of the studies examined ulcer recurrence rates, with one showing a recurrence rate in the amnion group of 14.3% versus 83.3% at 90 days, while the other found 5% recurrence versus 14% in the amnion and control group, respectively, at 112 days.
The different amniotic products used were Amnioband® (MTF Biologics), AmnioExcel® (Integra), EpiFix (MiMedx), Apligraf® (Organogenesis), Grafix® (Osiris), NEOX® CORD (Amniox Medical). The authors conclude that the current evidence suggests the use of amniotic membrane preparations for resistant DFUs may achieve relatively fast healing wound rates, but more evidence is required. In summary, I believe further research is needed, particularly in regards to ulcer relapse.