Microwave Radiometry Thermometry for the Diagnosis of Critical Limb Ischemia in Diabetic Patients

Attikon University Hospital

Status: Completed

Conditions: Diabetic Foot; Ischaemic Neuropathy; Peripheral Arterial Disease

Treatments: Other: Tissue thermometry using non-invasive microwave radiometry device

Study type: Interventional

Funder types: Other

Identifiers

NCT03002116

EBΔ 1310/10-2-16

Details and patient eligibility

About

Diagnosis of vascular involvement in diabetic foot disease remains challenging. Differential diagnosis between pure neuropathic or neuro-ischemic diabetic foot requires a combination of clinical examination, medical history and ankle-brachial index (ABI) measurement, which is considered the "gold standard" non-invasive modality for limb ischemia diagnosis. However, in diabetic patients with suspected arterial ischemia resulting in tissue loss (critical limb ischemia; CLI), false negative ABI results are frequent due to Monckeberg medial sclerosis producing incompressible vessels, while clinical signs are subjective and not accurate in posing definite diagnosis of CLI.

The investigators conducted a proof of concept study of the feasibility of microwave radiometry thermometry for non-invasive diagnosis of CLI in diabetic patients with tissue loss.

Full description

This is a prospective, multi-centre, trial designed to investigate the he feasibility and efficacy of microwave radiometry thermometry for non-invasive diagnosis of CLI in diabetic patients with tissue loss. The study included 80 patients, equally divided in four groups. Group N: normal subjects; group DN: diabetic patients with verified neuropathic ulcers without vascular involvement; group DC: diabetic patients with CLI and group NDC: non-diabetic patients with CLI. All patients underwent MWR with the RTM -01-RES device (University of Bolton, UK) to record the mean internal tissue temperature of the foot. MWR is based on the principle that the intensity of radiation is proportional to tissue temperature. The specific device is not commercially available and has been developed to detect temperatures from internal tissues at microwave frequencies. Foot temperature measurements were performed as near as possible at the site of ulceration in patients of groups DN, DC and NDC and in various sites in subjects of control group N.

Enrollment: 80 patients

Sex: All

Ages: 18 to 90 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Patients suffering from both insulin and not insulin dependent diabetes mellitus.
• Critical limb ischemia verified by both clinical examination, haemodynamic tests and digital subtraction angiography.

Exclusion criteria

• Uncertainty regarding the absence of peripheral arterial disease in groups N and DN.
• Uncertainty regarding the diagnosis of critical limb ischemia for patients in groups DC and NDC.

Trial design

Primary purpose: Diagnostic

Allocation: Non-Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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80 participants in 4 patient groups

Group N

Active Comparator group

Description:

Healthy volunteers without peripheral arterial disease according to clinical examination and Duplex ultrasound

Treatment:

Other: Tissue thermometry using non-invasive microwave radiometry device

Group DN

Experimental group

Description:

Patients suffering from diabetes and diabetic foot without vascular compromise according to clinical assessment continuous-wave Doppler and Duplex ultrasound

Treatment:

Other: Tissue thermometry using non-invasive microwave radiometry device

Group DC

Experimental group

Description:

Diabetic patients with Rutherford-Becker 5 or 6 critical limb ischemia, verified by clinical examination, abnormal continuous-wave Doppler or Duplex ultrasound and intra-arterial angiography.

Treatment:

Other: Tissue thermometry using non-invasive microwave radiometry device

Group NDC

Experimental group

Description:

Non diabetic patients with Rutherford-Becker 5 or 6 critical limb ischemia, verified by clinical examination, abnormal continuous-wave Doppler or Duplex ultrasound and intra-arterial angiography.

Treatment:

Other: Tissue thermometry using non-invasive microwave radiometry device