Ultrasound Assisted Wound Debridement (UAW) Versus Standard Wound Treatment in Complicated Diabetic Foot Ulcers (DFU)

• Methods

2.1. Trial design

A randomized and controlled parallel clinical trial was performed involving outpatients with complicated DFU that were admitted to specialized diabetic foot unit between November 2017 to December 2019. The study protocol received full approval from the Ethics Committee of the Hospital Clínico San Carlos, Madrid, Spain (C.P. - C.I. 16/484-P). Each patient provided written informed consent before inclusion.

2.1. Intervention

Participants were randomized and assigned to receive either surgical debridement or UAW debridement every week during a six-week treatment period.

Soft tissue punch biopsies (3mm) were taken after wound debridement sessions at week zero and week six.

2.2. Follow-up Patients were followed-up for 6 months after inclusion. During the follow-up period, the investigators recorded ulcer healing. Ulcer healing was defined as complete epithelialization without any sustained drainage up to 24 weeks after the end of the study follow-up.

2.3. Sample size The sample size was calculated using the Granmo v.12 program (Municipal Institute of Medical Research, Barcelona, Spain) (https://www.imim.cat/ofertadeserveis/software-public/granmo/ ). Therefore, we analyzed 51 patients (24 in surgical group and 27 en UAW group) with an alpha of 0.05 and a statistical power of 0.80.

2.4. Randomization A computer-generated random number table was used to carry out the randomization of the patients into the two groups by an investigator who was blinded to the identity of the participants.

2.5. Blinding None of the participants, care providers, and outcome adjudicators was blinded to the interventions after assignment.

2.6. Statistical Analysis Statistical analysis was performed using SPSS for IOs version 21.0 (SPSS, Inc. Chicago, IL, USA). The assumption of normality of all continuous variables was verified using the Kolmogorov-Smirnov test. Statistical differences between groups were calculated using the Chi-Square test and, where appropriate, Fisher's exact test for categorical variables. The Mann-Whitney U test was performed for abnormally distributed quantitative parameters, and Student's t-test was performed for quantitative variables that were distributed normally. The criteria of p < 0.05 was accepted as statistically significant with a confidence interval of 95%.

This study was conducted in accordance with the Declaration of Helsinki (2013 revision) and followed all local laws and regulations in clinical research investigations in patients.

Inclusion criteria

• • Male and female patients ≥18 years old

• Type 1 or type 2 diabetes with levels of HbA1c≤85.8 mmol/mol (10%) within 30 days of the beginning of the study
• Wound stages IB, IIB, ID, and IID according to the University of Texas Diabetic Wound Classification [11]
• Wound duration of 1-24 months
• Wound size between 1-30 cm2 after debridement
• Clinical picture of wounds showing mild or moderate infection, according to the criteria of the Infectious Disease Society of America Guidelines [12] and the European Wound Management Association (EWMA) [13]
• Ankle-brachial index (ABI) ≤0.9 and ankle systolic blood pressure (ASBP) ≥70mmHg, or toe systolic blood pressure (TSBP) ≥50mmHg, ABI>0.9, TSBP ≥50mmHg and toe-brachial index (TBI) ≤0.7

Exclusion criteria

• • Chronic renal disease or dialysis

• Non-treated osteomyelitis
• Necrotizing soft tissue infections
• Critical limb ischaemia patients with ABI≤0.5 and ASBP<70mmHg or <50mmHg
• Life expectancy <6 months due to malignant DFU
• Pregnancy and lactation
• Patients diagnosed with hepatitis or human immunodeficiency virus (HIV)
• Patients showing local or systemic conditions that may impair tissue repair