Диференційований підхід до прогнозування рівня ампутації залежно від порогових значень транскутанної оксиметрії в пацієнтів з ішемічними ураженнями на тлі цукрового діабету

Peripheral artery disease in patients with diabetes mellitus frequently leads to chronic limb-threatening ischemia and lower-limb amputation. Determining the optimal amputation level is crucial for preserving limb function; however, the absence of universal transcutaneous oximetry (TcpO₂) threshold values—particularly within the 20 — 40 mm Hg range—necessitates a level-dependent approach to its interpretation. Objective — to evaluate the prognostic role of TcpO₂ in selecting the level of lower-limb amputation and predicting postoperative wound healing, and to determine level-specific TcpO₂ threshold values to reduce the rate of major amputations in patients with the ischemic form of diabetic foot syndrome. Materials and methods. The study included 60 patients with ischemic diabetic foot syndrome associated with type 2 diabetes mellitus. Reconstructive vascular interventions were not feasible. The severity of the disease was assessed using the WIfI and SINBAD classifications. Ischaemia was evaluated using the ankle–brachial index, toe systolic pressure, and TcpO₂, as measured by the PeriFlux System 5000. Despite standard therapy, ulcer healing was not achieved, necessitating amputation. Results. In all 60 patients, a clear association was identified between TcpO₂ levels, the selected amputation level, and postoperative wound-healing outcomes. Critically low TcpO₂ values (< 20 mm Hg) were associated with major amputations. When TcpO₂ exceeded 40 mm Hg at the leg level, below-knee amputations resulted in 100% healing. Minor amputations were effective and accomplished with stump healing in patients with TcpO₂ values of 36 — 39 mm Hg at the foot level. Conversely, TcpO₂ < 36 mm Hg at the foot level was not associated with successful healing after distal procedures, whereas amputations at the leg level with TcpO₂ values of 30 — 36 mm Hg resulted in reliable wound healing. These findings confirm the level-dependent prognostic value of TcpO₂ and support a differentiated approach to amputation planning. Conclusions. Transcutaneous oximetry is an informative noninvasive method for assessing tissue perfusion in ischemic diabetic foot syndrome; however, its prognostic value is level-dependent. TcpO₂ values ≥ 36 mm Hg are critical for distal foot procedures, whereas values ≥ 30 mm Hg are sufficient for successful healing after below-knee amputation. Level-dependent interpretation of TcpO₂ optimizes amputation level selection, reduces unjustified high amputations, and increases the likelihood of knee joint preservation.