Pilot Study to Assess the Use of Spy Elite for Assessment of Amputation Healing

Study Overview
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Brief Summary
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The purpose of the study is to evaluate the use of the SPY Elite System to assess real-time tissue perfusion of lower extremity amputation sites and to develop parameters to predict healing of amputations at the time of surgery. This is a pilot study to see if the Spy Elite System is capable of recording accurate measurements on amputation sites to allow some correlation to healing. If this study shows promise for the device, the investigators would plan a larger study in which the data would be assessed in the operating room at time of acquisition and revision performed if needed based on the findings.

Detailed Description
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The pilot study is a prospective cohort study of consented subjects who require below knee or above knee amputation. The study will start with 18 subjects to assess proof of concept. If a correlation is identified, then a new proposal will be submitted with a larger cohort. Our hypothesis is that the Spy Elite System can help identify areas of poor tissue perfusion at the time of lower extremity amputation, and predict future potential wound healing complications. Primary outcome variables include wound healing at 30 days, and intra-operative imaging of amputation sites using the Spy Elite System. Secondary outcome variables include level of amputation, 30-day wound healing complications, readmission rate, need for revision, and subject demographics and co-morbidities. Subjects who agree to participation will undergo the amputations in the operating suite as per routine. The Spy Elite System will be implemented after final wound closure and prior to dressing placement. A single injection of 10 mg of Indocyanine Green will be administered, followed by 10 ml bolus of normal saline as per manufacturer IFU and recommendations (Attachments B, C, D). Recording from the Spy Elite Device will be saved for analysis. Also, a digital photograph of the surgical wound will be saved for comparison. No changes in operative management based on Spy Elite System will take place in this study. At subjects routine 30-day follow up appointment, wounds will be assessed for complications, a digital photograph of the incision will be saved, and secondary endpoints will be obtained. Possible correlations between perfusion values from the Spy Elite System recording and wound healing will be analyzed by the Investigators. The values will not be known until after the photos are taken and the investigators compare ischemic areas to normal areas based on the collected photographs.

Conditions
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Wound Healing, Lower Extremity Amputation, Above Knee Amputation, Below Knee Amputation

Intervention / Treatment
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* Procedure: Lower Extremity Amputation
* Device: SPY Elite Imaging System
* Drug: Indocyaine Green


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: All patients >= 18 years of age requiring Below Knee Amputation (BKA) or Above Knee Amputation (AKA) cared for by the vascular surgery service will be assessed for eligibility. Exclusion Criteria: Subjects with a history of allergies to iodides or iodinated contrast agents, pregnant or nursing women, subjects who are unable to provide consent, and prisoners will be excluded.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Lower Extremity Amputations<br>All patients >= 18 years of age requiring Below Knee Amputation (BKA) or Above Knee Amputation (AKA) cared for by the Spectrum Health vascular surgery service will be assessed for eligibility. Subjects with a history of allergies to iodides or iodinated contrast agents, pregnant or nursing women, subjects who are unable to provide consent, and prisoners will be excluded. Eighteen subjects will be enrolled in the pilot study. No special population subjects will be enrolled. | Procedure: Lower Extremity Amputation<br> <br> * Other names: Below Knee Amputation;Device: SPY Elite Imaging System<br>* The SPY Elite Imaging System is an adjunctive tool that can be used to assess tissue perfusion in real-time and provides surgeons with information that may change their operative plan before leaving the operating room. (http://novadaq.com/products/spy-elite) The system is comprised of two components, the first is the Spy Elite Kit, which is a single-use package containing one 25 mg vial of indocyanine green, one 10 ml vial of sterile Water for injection, and one SPY Elite sterile drape. The second component to the system is the SPY Elite Device which contains a near-infrared light source that illuminates the fluorescent agent within the tissues, an HD video camera captures the intensity of fluorescent marker in real-time, and software that allows the user to capture relative and absolute perfusion values within the surgical field.<br>* Other names: SPY Elite Kit;Drug: Indocyaine Green<br>* Indocyaine Green (ICG) is a non-nephrotoxic fluorescent imaging agent with a half-life of 2.5-3 minutes that is administered intravenously.<br>* Other names: ICG;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Wound Healing Post Lower Extremity Amputation | The primary outcome variable includes wound healing at 30 days and intra-operative imaging of amputation sites using the SPY Elite System. | 30 days post | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Level of Amputation | The secondary outcome variables include level of amputation. | Intra-operative | 
| Wound Healing | The secondary outcome variables include 30-day wound healing complications. | 30 days Post Lower Extremity Amputation | 
| Readmission Rates | The secondary outcome variables include readmission rates. | 30 days Post Lower Extremity Amputation | 
| Lower Extremity Amputation Revision | The secondary outcome variables include need for revision. | 30 days Post Lower Extremity Amputation | 
| Subject Demographics | The secondary outcome variables include subject demographics | Participants will be followed for the duration of the hospital stay and 30 days post lower extremity amputation | 
| Co-morbidities | The secondary outcome variables include co-morbidites. | Participants will be followed for the duration of the hospital stay and 30 days post lower extremity amputation |