Pilot Study to Determine Percent Tissue Perfusion and Cellular Viability Using SPY Imaging

NCT ID: NCT01522495

Last Updated: 2020-03-11

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 31 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2013-04-30
• Study Completion Date: 2019-12-31

Brief Summary

Little is known about chronic wound microenvironments, especially in peripheral vascular disease (PVD) and diabetic patients. At the demarcation line, the percentage of viable cells and tissue is unclear. A means to determine cell viability, particularly discerning an apoptotic or necrotic cell pathway would indicate where the line of demarcation should be drawn. The information generated would better predict clinical outcome using SPY Imaging. Cellular studies are needed to successfully confirm a clear line of demarcation to eliminate surgeon subjectivity.

Detailed Description

Peripheral arterial disease (PAD), like other more central macrovascular diseases, is common in diabetes. PAD can lead to critical limb ischemia, either alone or when combined with an injury like a foot ulcer. The diabetic foot ulceration requires adequate circulation to heal; if the circulation is impaired such that the tissue oxygen demand exceeds supply, critical limb ischemia ensues, placing the limb at risk.

Most often, patients with critical limb ischemia, undergo multiple debridements in the operating room as well as vascular procedures, prior to reaching a viable level of amputation. This increases the patients' co-morbidities from repetitive exposure to anesthesia. Each debridement may be removing viable tissue and decreasing the length of the eventual amputation. Additionally, intraoperatively, the viability of the skin edges is a subjective assessment based on the surgeon's experience. That judgement can be inaccurate in 10-20% of cases and lad to reoperation. With the use of the SPY imaging system, a better assessment of not only macrovascularity, but also microvascularity of the tissues is able to be evaluated objectively. This helps identify the tissues that are underperfused.

The investigators are unaware of any literature evaluating the use of SPY imaging in the lower extremities intraoperatively during amputations or debridements. There are many studies published for the use of this technology during ophthalmic procedures , cerebral aneurismal repair, cardiac surgery and breast reconstruction. In cardiac surgery, the use of ICG based imaging has proven to be helpful in assessing the quality of bypass grafts and eliminating the need for radiography or catheter insertion (Reuthebuch et al., 2004). In ophthalmic procedures, ICG angiography has been fundamental in identifying many microvascular pathologies (Slakter, Yannuzzi, Guyer, Sorenson, & Orlock, 1995). Furthermore, neurosurgeons have found that the use of ICG angiography is far more superior than DS angiography in identifying small vessels . As it has already been proven to be a good adjunct intraoperatively to visualize microvasculature, the investigators would like to apply this to the lower extremities. Identifying underperfused tissues intraoperatively can help the surgeon objectively decide an appropriate level of amputation/debridement to effectively minimize the number of revisional surgeries. Also, there are no studies that comprehensively evaluate and compare the effectiveness of other modalities that also attempt to assess vascularity with the SPY imaging system. The information gained could be pivotal and help to gain more insight in patients with difficult to heal wounds, especially in the presence of PVD.

Conditions

Peripheral Vascular Disease

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: NONE

Study Groups

SPY Imaging

SPY Imaging Prior to Amputation or Debridements (50 participants)

Group Type: EXPERIMENTAL

SPY Imaging, ICG dye (0.2 - 0.5 mg/kg)

Intervention Type: DEVICE

Intravenous(1X) in conjunction with SPY Imaging (1 arm)

SPY Imaging

Intervention Type: DEVICE

SPY Imaging to assess tissue perfusion

No SPY Imaging

Amputation or Debridements as Standard of Care (50 participants)

Group Type: NO_INTERVENTION

No interventions assigned to this group

Validation Against Angiogram

Patients who are scheduled to undergo an angiogram will also receive ICG angiography (SPY). This will occur at specific time points: 1.) before the angiogram/intervention is performed 2.) immediately after the angiogram/intervention is performed 3.) 5-7 days after angiogram/intervention 4.) 21-30 days after angiogram/intervention.

(30 participants)

Group Type: EXPERIMENTAL

SPY Imaging, ICG dye (0.2 - 0.5 mg/kg)

Intervention Type: DEVICE

Intravenous(1X) in conjunction with SPY Imaging (1 arm)

SPY Imaging

Intervention Type: DEVICE

SPY Imaging to assess tissue perfusion

Establishing Normal Values

To establish baseline lower extremity perfusion in non-PVD patients. Patients requiring an angiogram for other vascular processes unrelated to the lower extremity will be recruited into this study. ICG angiography (SPY) of the lower extremity will be performed at the time of the angiogram. (30 Participants)

Group Type: EXPERIMENTAL

SPY Imaging, ICG dye (0.2 - 0.5 mg/kg)

Intervention Type: DEVICE

Intravenous(1X) in conjunction with SPY Imaging (1 arm)

SPY Imaging

Intervention Type: DEVICE

SPY Imaging to assess tissue perfusion

Interventions

SPY Imaging, ICG dye (0.2 - 0.5 mg/kg)

Intravenous(1X) in conjunction with SPY Imaging (1 arm)

Intervention Type: DEVICE

SPY Imaging

SPY Imaging to assess tissue perfusion

Intervention Type: DEVICE

Other Intervention Names

Indocyanine Green, IC-GREEN

Eligibility Criteria

Inclusion Criteria

• Subject is at least 18 years or older.
• Subject has PVD demonstrated by angiogram.
• Subject is undergoing the first amputation/debridement after vascular intervention, if intervention is/was warranted.
• Subject has had a vascular consult and/or intervention.
• Subject must sign an IRB approved informed consent.
• Subject is willing and able to complete required follow up.

Exclusion Criteria

• Subject has no evidence of PVD
• Subject's wound presents with a malignancy in the wound bed.
• Subject has liver disease (Previously diagnosed with liver disease or elevated AST, ALT, Alk Phos, or Bilirubin labs within 30 days of procedure).
• Subject has a disorder or situation that the investigator believes will interfere with study compliance.

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Georgetown University

OTHER

Sponsor Role: lead

Responsible Party

Christopher Attinger, M.D.

Chief of the Division of The Center for Wound Healing

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Christopher E Attinger, MD

Role: PRINCIPAL_INVESTIGATOR

Georgetown University

Locations

Georgetown University Medical Center; Center for Wound Healing

Washington D.C., District of Columbia, United States

Countries

United States

Other Identifiers

2011-114

Identifier Type: OTHER

Identifier Source: secondary_id

Eye vs. Spy Pilot Study

Identifier Type: -

Identifier Source: org_study_id