Critical limb ischemia is a serious form of peripheral arterial disease (PAD). The consequences of lower limb ischemia are pain, claudication and chronic non‐healing wounds. Patients with diabetes are especially at a high risk for developing non‐healing ulcers. The most serious complication is major amputation. For this reason, there is a significant medical requirement to develop new therapies in order to prevent the progression of PAD. For research purposes, it is crucial to find an appropriate model of chronic ischemia to explore the processes of wound healing. According to recently acquired information, rodents are currently the most commonly used animals in these types of studies. The main advantage of using small animals is the low financial cost due to the relatively small demand for food, water and living space. The disadvantage is their anatomy, which is different from that of humans. Larger animals have a more human‐like anatomy and physiology, but they require more expense and space for housing. A bipedicle skin flap and its modifications are popular models for ischemic wounds. In order to secure healing through re‐epithelisation, as opposed to contraction in rodents, there is a need to remove the panniculus carnosus muscle. Wounds in other experimental animals heal primarily through re‐epithelisation. The application of a silicone mesh underneath the flap prevents vascular regrowth in ischemic tissue. There is an ongoing effort to create in vivo diabetic models for chronic ulcer research. This work presents an overview of existing animal models of ischemic wounds.

Introduction. Autologous cell therapy (ACT) is one of the last options for limb salvage in patients with chronic limb-threatening ischemia (CLTI) and diabetic foot ulcers (DFU). However, some patients may still undergo a major amputation even after ACT, but the risk factors for this are not known. Therefore, the aim of our study was to assess the risk factors for major amputation in patients with CLTI and DFU during a 2-year follow-up after ACT. Methods. One hundred and thirteen patients after ACT were included in our study and divided into two groups: Group 1 with major amputation (AMP; n = 37 ) and Group 2 without amputation (nAMP, n = 76 ). The risk factors for major amputation were evaluated before ACT and included factors relating to the patient, the DFU, and the cell product. Results. The AMP group had significantly higher C-reactive protein (CRP) levels compared to the nAMP group (22.7 vs. 10.7 mg/L, p = 0.024 ). In stepwise logistic regression, independent predictors for major amputation were mutation of the gene for methylenetetrahydrofolate reductase (MTHFR) with heterozygote and homozygote polymorphism 1298 (OR 4.33 [95% CI 1.05-17.6]), smoking (OR 3.83 [95% CI 1.18-12.5]), and CRP > 10   mg / L (OR 2.76 [95% CI 0.93-8.21]). Lower transcutaneous oxygen pressure (TcPO2) values were observed in AMP patients compared to the nAMP group at one month (24.5 vs. 33.2, p = 0.012 ) and at 3 months (31.1 vs. 40.9, p = 0.009 ) after ACT. Conclusion. Our study showed that the risk for major amputation after ACT in patients with CLTI and DFU is increased by the presence of MTHFR heterozygote and homozygote gene mutations, smoking, and higher CRP at baseline. Lower TcPO2 at one and 3 months after ACT may also have a predictive value. Therefore, it is necessary to stop smoking before ACT, treat any infection, and, above all, consider antiaggregation or anticoagulant treatment after the procedure.