Fig. 6.

Calf muscle biopsy sampling confirms muscle degeneration in PAD. A Trichrome (TriC) and sirius red (SiR) staining results. Grouping was based on the clinical disease severity (HV; no clinical PAD symptoms, normal ankle-brachial-index (ABI) and palpable foot pulses; IC; combined Fontaine IIa: claudication at a distance > 200 m and IIb: claudication at a distance < 200 m; CLTI; combined Fontaine III: rest pain, mostly in the feet and IV: necrosis and/or gangrene of the limb). Musculature of the CLTI patient shows a more inhomogeneous pattern of myofibers of varying size and shape and increased collagen content (red/ turquoise). B Quantitation of positively stained area in SiR staining based on clinical disease severity. C Quantitation of total collagen per total protein derived by photometric assay. Independent samples t-test was used for statistical analysis. If normal distribution could not be assumed, the Mann-Whitney U-test was applied.