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

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01522495
Recruitment Status : Active, not recruiting
First Posted : January 31, 2012
Last Update Posted : June 1, 2018
Information provided by (Responsible Party):
Christopher Attinger, M.D., Georgetown University

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.

Condition or disease Intervention/treatment Phase
Peripheral Vascular Disease Device: SPY Imaging, ICG dye (0.2 - 0.5 mg/kg) Device: SPY Imaging Not Applicable

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.

Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 160 participants
Allocation: Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Basic Science
Official Title: Pilot Study for: Eye vs. Spy - A Prospective, Randomized Study Evaluating Patient Outcomes With the Use of SPY Imaging During Amputations or Debridements
Study Start Date : April 2013
Estimated Primary Completion Date : December 2018
Estimated Study Completion Date : December 2018

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Experimental: SPY Imaging
SPY Imaging Prior to Amputation or Debridements (50 participants)
Device: SPY Imaging, ICG dye (0.2 - 0.5 mg/kg)
Intravenous(1X) in conjunction with SPY Imaging (1 arm)
Other Name: Indocyanine Green, IC-GREEN

Device: SPY Imaging
SPY Imaging to assess tissue perfusion

No Intervention: No SPY Imaging
Amputation or Debridements as Standard of Care (50 participants)
Experimental: 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)

Device: SPY Imaging, ICG dye (0.2 - 0.5 mg/kg)
Intravenous(1X) in conjunction with SPY Imaging (1 arm)
Other Name: Indocyanine Green, IC-GREEN

Device: SPY Imaging
SPY Imaging to assess tissue perfusion

Experimental: 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)
Device: SPY Imaging, ICG dye (0.2 - 0.5 mg/kg)
Intravenous(1X) in conjunction with SPY Imaging (1 arm)
Other Name: Indocyanine Green, IC-GREEN

Device: SPY Imaging
SPY Imaging to assess tissue perfusion

Primary Outcome Measures :
  1. Determination of percent cellular viability [ Time Frame: 6 weeks ]
    Determine percent cellular viability (vs. apoptotic/dead) of cells at demarcation line

  2. Rate of infection, dehiscence and re-amputation [ Time Frame: 20 weeks ]
    Rate of infection, dehiscence and re-amputation in patients undergoing SPY imaging

  3. Number of debridements, revisional surgeries and days of stay in hospital [ Time Frame: 20 weeks ]
    The endpoint for evaluation will be the number of revisional surgeries and number of days of stay in hospital within 20 weeks of the first procedure.

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

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.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT01522495

United States, District of Columbia
Georgetown University Medical Center; Center for Wound Healing
Washington, District of Columbia, United States, 20007
Sponsors and Collaborators
Georgetown University
Principal Investigator: Christopher E Attinger, MD Georgetown University
Study Director: Paul J Kim, DPM Georgetown University

Responsible Party: Christopher Attinger, M.D., Chief of the Division of The Center for Wound Healing, Georgetown University Identifier: NCT01522495     History of Changes
Other Study ID Numbers: Eye vs. Spy Pilot Study
2011-114 ( Other Identifier: IRB )
First Posted: January 31, 2012    Key Record Dates
Last Update Posted: June 1, 2018
Last Verified: May 2018

Additional relevant MeSH terms:
Vascular Diseases
Peripheral Vascular Diseases
Peripheral Arterial Disease
Cardiovascular Diseases
Arterial Occlusive Diseases