Impact of Active Thermoregulation on the Microcirculation of Free Flaps

Study Overview
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Brief Summary
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This study evaluates the impact of active thermoregulation on free flap microcirculation following free flap transfer. Thermoregulation is performed by passive warming, active warming (water circulation based device) and active cooling. Changes in microcirculation are assessed using combined laser Doppler flowmetry and remission spectroscopy.

Detailed Description
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Measurements are conducted at the day of the operation as well as the first three days following the operation. Tissue temperature is assessed by a temperature measurement probe that is placed 8 mm underneath the skin. The microcirculation parameters of free perforator flaps are assessed using combined laser Doppler flowmetry and remission spectroscopy (O2C®). This allows non-invasive measurement of blood flow, capillary venous oxygen saturation and relative postcapillary filling pressure using a fiber optic probe that is placed on the flap surface. Controlled Thermoregulation (between 10 and 38°C) is enabled using a water circulation based system (Hilotherm Clinic®).

Official Title
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Impact of Active Thermoregulation on the Microcirculation of Free Flaps

Conditions
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Microcirculation, Thermoregulation, Free Flap

Intervention / Treatment
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* Device: Hilotherm Clinic®


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients receiving free perforator flaps with a skin island not less than 4x4 cm Exclusion Criteria: non-compliance, non-consent, history of cardiac disease, arterial hypo- or hypertension, intake of vasoactive drugs, peripheral arterial occlusive disease, chronic kidney and liver disease, vasculitis

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 50 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Supportive Care
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Hilotherm Clinic®<br>Intervention: Controlled Thermoregulation with Hilotherm Clinic® - Flap Temperature is altered by passive warming (dressing), active warming (38 C) and active cooling (10 C) each for 60 minutes following free flap transfer in every subject at the day of surgery and the following three days | Device: Hilotherm Clinic®<br>* Controlled Thermoregulation using a water circulation based system (Hilotherm Clinic®). Controlled Thermoregulation with Hilotherm Clinic® - Flap Temperature is altered by passive warming (dressing), active warming (38 C) and active cooling (10 C) each for 60 minutes following free flap transfer in every subject at the day of surgery and the following three days<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Blood Flow (AU) measured by Doppler flowmetry and remission spectroscopy (Oxygen to See, O2C®, Lea Medizintechnik, Giessen, Germany) |  | Measurements were conducted at the day of the operation |