BIOMICROSCOPY HIGHLIGHTS THE EFFICACY OF SKIN GRAFT ON MICROVASCULAR PARAMETERS IN NON-DIABETIC ULCERS

Abstract

Objective. Laser Doppler owmetry (LDF), transcutaneous partial pressure of oxygen (pO2) and carbon dioxide (pCO2), and Biomicroscopy (BM) are exams used in daily clinical practice to assess capillary and microvascular functionality. Skin graft (SG) is a well-established intervention for the treatment of chronic lower leg ulcers. The sequence of improvements at the microvascular and macrovascular level, letting to a successful outcome after SG, is not yet been determined. This observation aims to determine which parameters of capillary functionality could show how SG takes to a positive outcome. Methods. In this trial, cutaneous perfusion, district microcirculatory reserve, and variation of cutaneous perfusion induced by the postural vasoconstriction reex (VAR) were measured with LDF as the number and diameter of capillary loops at 1 cm, 2 cm, and 4 cm from the big toe nailfold and the ulcer edge. Cutaneous gas exchanges were detected through pO2 and pCO2, and capillary density and average diameter loops were recorded with BM. Because of the exploratory nature of this study, consecutive patients' afferent to our structure receiving SG for the treatment of non-diabetic chronic non-relapsing ulcers on the lower limb, were assessed before and 5 days after SG. All measures were collected by the same operator and SG was performed in a standardized manner. Paired non-parametric statistical tests were performed to compare basal with after SG measurements. Results. All 13 patients observed had a clinically successful outcome after SG in terms of pain reduction, absence of SG complications, and absence of secretion. The median number of capillary loops changed at the different evaluation points (e.g. from 19 vs 21 (P=.004) at the big toe nailfold and 16 vs. 22 (P<.001) at 2 cm from the ulcer edge). The median diameter of capillary loops changed at the different evaluation points (e.g. at the big toe nailfold decreased from 24mm to 19mm (P=.004) and from 16mm to 22mm (P=.031) at 2 cm from the ulcer). The median values of pO2 increased from 10 mmHg to 36 mmHg (P=.005) on supine and from 28 mmHg to 3 mmHg (P=.006) at the dependent lower limb None of the LDF measures, or pCO2.Conclusion.In this exploratory evaluation, BM measurements reveal, for the rst time, a successful outcome after SG for the treatment of chronic lower limb skin ulcers, especially on the big toe nailfold, 1 and 2 cm from the ulcer. The improvement observed at the capillary level seems parallel with the improvement of tissue oxygenation