Patients having DPN(P) with/without DFUs undergo lymphovenous bypass and biopsy at foot dorsum. DPN n = 10, DPNP n = 10, DFU n = 20

A lymphovenous bypass procedure using a lymphangiography dye (Patent Blue V or indocyanine green), 0.2 mL was injected into the skin at the toe webspaces preoperatively. 8,13,14 The paths of lymphatic vessels were traced. On the foot dorsum of the affected limb, a horizontal incision of 2-3 cm was made close to the lymphatic vessel's pathway. Under the surgical microscope, suitable lymphatic and venous vessels were identified, usually located above the deep fascia (on the superficial side, ensuring that the extensor hallucis longus tendon remains unexposed). The coaptation between the lymphatic vessels and venules followed the same principles as those for vascular anastomosis by using higher magnification under the surgical microscope (approximately 20×), finer microsurgical instruments, and 11- or 12-0 nylon sutures.

Sudoscan is a non-invasive medical device that assesses sweat gland function, specifically measuring sweat chloride concentrations in the palms and soles. This provides an indirect measure of small fiber neuropathy, as these nerve fibers innervate the sweat glands. The test involves placing a patient's hands and feet on electrodes, and a low-voltage electrical current is passed through the skin. The device then calculates electrochemical skin conductance (ESC). Abnormal ESC values can indicate autonomic neuropathy, a common complication of conditions like diabetes, affecting nerves responsible for involuntary bodily functions.

HRV measures the variation in time between consecutive heartbeats. It reflects the balance and responsiveness of the autonomic nervous system, specifically the sympathetic ("fight or flight") and parasympathetic ("rest and digest") branches. A higher HRV generally indicates a more flexible and adaptable nervous system, associated with better health and stress resilience. A lower HRV can signal chronic stress, fatigue, or underlying health issues. It is a non-invasive tool used to assess cardiovascular health and monitor recovery.

QST is a non-invasive method for assessing the function of sensory nerve fibers. It measures a person's ability to feel and respond to various stimuli, such as temperature (cold and warm detection thresholds) and vibration. By applying controlled stimuli and recording the patient's perception, clinicians can identify and quantify sensory deficits. QST helps diagnose and monitor conditions affecting the peripheral nervous system, such as diabetic neuropathy, and can be used to track disease progression or the effectiveness of treatments.

The MNSI is a two-part tool for screening for diabetic peripheral neuropathy. The first part is a 15-item patient questionnaire that asks about common neuropathic symptoms like numbness, burning pain, and muscle cramps. The second part is a physical examination conducted by a healthcare professional. This exam includes a visual inspection of the feet for deformities or ulcers, an assessment of ankle reflexes, and a crucial test of vibratory sensation using a tuning fork. The MNSI provides a quick, cost-effective way to identify patients who may need further diagnostic evaluation for neuropathy.