Clinical Efficacy of Modified Simiao Yongan Decoction and Endovascular Therapy for Diabetic Foot Ulcers

This is a single-center, prospective, non-randomized, parallel-controlled cohort study designed to address the clinical challenge of delayed diabetic foot ulcer (DFU) healing despite upstream vascular recanalization. The study will enroll 120 patients, assigned to either a standard treatment control group or an experimental group. The control group will receive standard endovascular intervention, an anti-thrombotic regimen, and standard wound care. The experimental group will receive these same standard treatments plus a one-month regimen of Modified Simiao Yongan Decoction.

The study's primary endpoints evaluate Major Adverse Limb Events (MALE) and Major Adverse Cardiovascular Events (MACE). Secondary clinical outcomes include the complete ulcer healing time, clinical-driven target lesion revascularization (CD-TLR), ankle-brachial index (ABI), transcutaneous oxygen pressure (TcPO2), and changes in Traditional Chinese Medicine syndrome scores and VascuQoL-6 scores.

In addition to clinical metrics, the research investigates the underlying molecular mechanisms, specifically how the intervention regulates the vascular-immune microenvironment through the HIF-1α/VEGF pathway and macrophage polarization to promote angiogenesis and tissue repair. Statistical analyses will employ Inverse Probability of Treatment Weighting (IPTW) to balance baseline characteristics and the Fine-Gray competing risk model for robust outcome evaluation.

• Modified Simiao Yongan Decoction (Drug): A 1-month course of oral granules administered following standard endovascular revascularization.
• Endovascular Therapy and Standard Care (Procedure): Standard revascularization via endovascular intervention, supplemented with a standardized post-operative antithrombotic regimen. Standard care also includes strict blood glucose control, infection management, wound decompression, regular dressing changes, and necessary nutritional support.

Primary outcomes

• Incidence of Major Adverse Limb Events (MALE) [Up to 24 months post-operatively]: A composite endpoint defined as major amputation of vascular etiology or clinical-driven target lesion revascularization (CD-TLR)
• Incidence of Major Adverse Cardiovascular Events (MACE) and Major Bleeding. [Up to 24 months post-operatively]: A composite endpoint defined as cardiovascular death, non-fatal myocardial infarction, and non-fatal ischemic stroke, alongside any major bleeding events requiring medical intervention.

Secondary outcomes

• Complete Ulcer Healing Rate and Time [Assessed at 1, 3, 6, and 12 months post-operatively.]: The rate and total time required for the target diabetic foot ulcer to completely heal.
• Ankle-Brachial Index (ABI) [Baseline and 1, 3, 6, and 12 months post-operatively.]: The ankle-brachial index (ABI) of the target limb will be measured to assess lower-extremity macrovascular perfusion. ABI is calculated as the ratio of ankle systolic blood pressure to brachial systolic blood pressure.
• Transcutaneous Oxygen Pressure (TcPO2) [Baseline and 1, 3, 6, and 12 months post-operatively.]: Transcutaneous oxygen pressure (TcPO2) of the target limb will be measured in mmHg to assess local tissue oxygenation and microcirculatory perfusion.
• Traditional Chinese Medicine Damp-Heat Toxins Accumulation Syndrome Score [Assessed at 1, 3, 6, and 12 months post-operatively.]: The Traditional Chinese Medicine Damp-Heat Toxin Accumulation Syndrome Score is used to assess the severity of syndrome-related symptoms and signs. The scale consists of eight items, including four primary symptoms and four secondary symptoms. Each item is scored from 0 to 3, where 0 indicates absence of the symptom and 3 indicates severe manifestations. The total score ranges from 0 to 24, with higher scores indicating greater syndrome severity and therefore a worse outcome.
• Vascular Quality of Life Questionnaire-6 (VascuQoL-6) Score [Assessed at 1, 3, 6, and 12 months post-operatively.]: The Vascular Quality of Life Questionnaire-6 (VascuQoL-6) is a six-item disease-specific questionnaire used to assess health-related quality of life in patients with peripheral arterial disease. Each item is scored from 1 to 4, resulting in a total score ranging from 6 to 24. Higher scores indicate better health-related quality of life and therefore a better outcome.

Sex: All, ages: 18 Years to any

Inclusion Criteria:

* Diagnosed with a Diabetic Foot Ulcer (DFU).
* Assessed as Rutherford classification 4-5 or Wagner classification 2-4.
* Successfully received lower extremity endovascular intervention.
* Meets the Traditional Chinese Medicine diagnostic criteria for "Damp-Heat Toxins Accumulation Syndrome". Patients must exhibit at least two primary symptoms (red/swollen/hot/painful limb, high exudate or purulent secretion with foul odor, dark purple wound/necrotic tissue, elevated local skin temperature) and at least one secondary symptom (dry mouth/bitter taste, dry stool, red tongue with yellow greasy coating, rapid/string-taut pulse).

Exclusion Criteria:

* Patients with severe, uncontrolled life-threatening systemic diseases, such as severe heart failure (NYHA class III-IV), severe hepatic or renal dysfunction, or active malignancy.
* Patients with active systemic sepsis, extensive gangrene, or severe osteomyelitis requiring immediate major amputation of the target limb.
* Patients with known allergies, hypersensitivity, or severe adverse reactions to any of the herbal components of the Modified Simiao Yongan Decoction.
* Patients with severe gastrointestinal disorders that would significantly impair the absorption of oral medications.
* Women who are pregnant, planning to become pregnant, or currently lactating.
* Patients with severe cognitive impairment, psychiatric disorders, or poor compliance that would prevent them from providing informed consent or adhering to the 24-month follow-up schedule.
* Patients currently participating in, or who have participated in within the last 30 days, another interventional clinical trial.