Peripheral Arterial Disease
Conditions
Keywords
saphenous vein bypass grafts, flow-mediated vasodilation
Brief summary
This study will determine whether or not saphenous vein \[arterial\] bypass grafts in the leg relax in response to increases in blood flow.
Detailed description
Subjects who have undergone saphenous vein \[arterial\] bypass grafts from the femoral to above-knee popliteal artery will undergo ultrasound imaging at rest, and again after 5 minutes of blood pressure cuff occlusion of the calf. (at 1 minute and 15 minutes) Subjects will then be given sub-lingual nitroglycerin, and repeat ultrasound will be performed 3 minutes later. Following 10 minutes of rest, subjects will be given intravenous L-NMMA, a specific nitric oxide inhibitor, to help determine the responsible agent of the vein graft flow mediated dilation.
Interventions
DRUGL-N^G monomethyl arginine (L-NMMA)
L-NMMA was infused at a dose of 1 mg/kg over 10 minutes to competitively inhibit the production of nitric oxide. Ultrasound imaging of the saphenous vein \[arterial\] bypass at baseline, and following an ischemic stimulus, administration of sublingual nitroglycerin, and intravenous administration of L-NMMA.
Sponsors
Brigham and Women's Hospital
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
SINGLE (Outcomes Assessor)
Masking description
Investigators who analyzed the results of vascular function testing were blinded to the participant identity.
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Adults who have undergone femoral artery to above-knee popliteal artery saphenous vein bypass grafts
Exclusion criteria
* Amputation beyond the toes * Critical limb ischemia defined as rest pain, non-healing ulceration or gangrene * Pregnancy
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change From Baseline in Saphenous Vein Bypass Graft Vasodilation | Single visit study | Flow-mediated, endothelium-dependent vasodilation was determined by comparing baseline vein graft diameter with vein graft diameter as measured after deflation of a 2.5-inch wide sphygmomanometric cuff that had been inflated to suprasystolic pressure for 5 minutes. The cuff was never placed directly over the graft. Vasodilation of the vein graft was determined by acquiring images at 1 minute after cuff deflation. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Study Population All 19 study subjects had continuously patent femoral-to-popliteal arterial bypass with autogenous greater saphenous vein. Ultrasound imaging of saphenous vein bypass graft followed an ischemic stimulus and administration of sublingual nitroglycerin. In the last 6 consecutive subjects, L-N\^G monomethyl arginine (L-NMMA) was administered intravenously. | 19 |
| Total | 19 |
Baseline characteristics
| Characteristic | Study Population |
|---|---|
| Age, Continuous | 64.7 years STANDARD_DEVIATION 9 |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants |
| Race (NIH/OMB) Black or African American | 1 Participants |
| Race (NIH/OMB) More than one race | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 2 Participants |
| Race (NIH/OMB) White | 16 Participants |
| Region of Enrollment United States | 19 participants |
| Sex: Female, Male Female | 5 Participants |
| Sex: Female, Male Male | 14 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 19 |
| other Total, other adverse events | 0 / 19 |
| serious Total, serious adverse events | 0 / 19 |
Outcome results
Primary
Change From Baseline in Saphenous Vein Bypass Graft Vasodilation
Flow-mediated, endothelium-dependent vasodilation was determined by comparing baseline vein graft diameter with vein graft diameter as measured after deflation of a 2.5-inch wide sphygmomanometric cuff that had been inflated to suprasystolic pressure for 5 minutes. The cuff was never placed directly over the graft. Vasodilation of the vein graft was determined by acquiring images at 1 minute after cuff deflation.
Time frame: Single visit study
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Study Population | Change From Baseline in Saphenous Vein Bypass Graft Vasodilation | 5.28 vein bypass graft size increase (%) | Standard Error 3.1 |