What is meant by single vessel two vessel or three vessel runoff?

The terms “single vessel,” “two-vessel,” and “three-vessel runoff” are terminologies often used in the context of coronary angiography, a medical procedure that involves injecting a contrast dye into the coronary arteries to visualize the blood vessels supplying the heart muscle. These terms describe the number of major coronary arteries involved in supplying blood to the heart.

1. Single Vessel Disease:
   • In single vessel disease, only one of the three main coronary arteries is significantly affected by atherosclerosis or blockage. The three main coronary arteries are the left anterior descending artery (LAD), the circumflex artery (LCx), and the right coronary artery (RCA). Single vessel disease indicates that the disease or blockage is primarily localized to one of these arteries.
2. Two-Vessel Disease:
   • Two-vessel disease refers to the presence of significant blockages or atherosclerosis in two out of the three main coronary arteries. This can involve different combinations of arteries, such as LAD and LCx or LAD and RCA, among others.
3. Three-Vessel Disease:
   • Three-vessel disease indicates that all three major coronary arteries are affected by blockages or atherosclerosis. This is a more extensive and severe form of coronary artery disease (CAD) and may increase the risk of complications, including myocardial infarction (heart attack) and other cardiovascular events.

Runoff refers to the patency and quality of distal vessels (especially below the site of an arterial lesion) that receive blood after revascularization procedures such as bypass surgery, angioplasty, or stenting. It’s primarily used in assessing lower extremity arterial disease.

Why runoff number matters

• Greater patent runoff (two- or three-vessel) is associated with improved conduit patency and durability after revascularization, reflecting better outflow and hemodynamics in observational series and policy reviews.​
• Treating a single critical runoff vessel can carry higher risk during BTK endovascular procedures because loss of that sole channel can compromise perfusion, prompting some experts to favor multivessel where feasible and safe.​
• However, limb salvage and wound healing can still be achieved with single-vessel runoff in carefully selected cases, especially with “angiosome-directed” flow to the wound bed or when reconstructive techniques are used adjunctively.

Three-Vessel Runoff

• Involves all three major infrapopliteal arteries:
  1. Anterior tibial artery
  2. Posterior tibial artery
  3. Peroneal (fibular) artery
• Significance:
  • Indicates excellent distal circulation
  • Predicts better outcomes in peripheral interventions
  • Associated with high graft patency and wound healing potential

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Two-Vessel Runoff

• Two of the three infrapopliteal arteries are patent and supplying blood flow
• Significance:
  • Good, but less optimal than three-vessel runoff
  • Still generally adequate for successful revascularization
  • Often acceptable in bypass graft planning or angioplasty

Why Is Single vessel two vessel or three vessel Runoff Important?

1. Predicts the Success of Revascularization

• Better runoff = Better outcomes for procedures like angioplasty, stenting, or bypass.
• Three-vessel runoff is ideal and associated with higher primary patency and limb salvage rates.
• Poor runoff (e.g., single-vessel) increases the risk of early failure or restenosis.

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2. Guides Bypass Graft Targeting

• Surgeons aim to anastomose grafts to arteries with good runoff to ensure adequate outflow and long-term graft patency.
• A bypass to a single-vessel runoff limb is less durable and needs careful planning.

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3. Affects Amputation Risk and Wound Healing

• Patients with multiple patent distal vessels have better tissue perfusion, leading to:
  • Faster wound healing
  • Reduced risk of critical limb ischemia (CLI)
  • Lower rates of major amputation

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4. Determines Intervention Approach

• Endovascular-first vs. surgical-first strategy may depend on runoff quality.
• In poor runoff, endovascular interventions may be less effective, and staged procedures or endarterectomy may be needed.

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5. Used in Scoring Systems

• Scoring tools like the TASC II classification and GLASS staging for PAD take runoff quality into account to guide treatment.
• Imaging (CTA, MRA, or DSA) is used to quantify and assess runoff pre-procedure.

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Clinical Implications of Poor Runoff:

Runoff Type	Outcome/Implication
Three-vessel	Best outcomes, high graft patency, fast healing
Two-vessel	Moderate outcomes; still favorable for bypass
Single-vessel	Higher failure risk, slower healing, higher amputation risk
No-vessel	Often not suitable for intervention; consider amputation or conservative care

Assessment Tools

• CT Angiography (CTA)
• MR Angiography (MRA)
• Digital Subtraction Angiography (DSA)
• Duplex ultrasound

The classification of single vessel, two-vessel, or three-vessel runoff is important for assessing the severity of peripheral arterial disease and determining the appropriate treatment approach. The extent of arterial disease influences the choice of treatment options, such as medication management, endovascular interventions (such as angioplasty or stenting), or surgical revascularization procedures (such as bypass surgery).

The specific treatment plan for a patient with PAD will depend on various factors, including the location and severity of the blockages, overall health status, and individual preferences. It is important for individuals with PAD to work closely with their healthcare providers, usually vascular specialists, to determine the most appropriate treatment strategy based on their unique circumstances.

Single vessel two vessel or three vessel runoff are terms commonly used in the context of peripheral arterial disease (PAD) to describe the extent of arterial occlusion or stenosis in the lower extremities.

These terms refer to the number of major arteries that are affected by significant blockages or narrowing in the leg arteries.

These terms are often used in clinical assessments and diagnostic reports to describe the severity and extent of arterial disease in PAD patients.

The extent of arterial occlusion or stenosis can help guide treatment decisions, such as revascularization procedures (e.g., angioplasty, stenting, bypass surgery), to improve blood flow and alleviate symptoms.

• There are three infrapopliteal arteries: anterior tibial, posterior tibial, and peroneal arteries. The peroneal artery, the posterior tibial artery, and the anterior tibial artery are commonly referred to as the three-vessel runoff.
• The number of these calf vessels that are continuously patent from the origin to the ankle defines the number of runoff vessels.
• A higher number usually corresponds to a better prognosis after surgery or endovascular procedures.

What latest research says about single vessel two vessel or three vessel runoff?

Prognostic Significance Based on Runoff Status

Contemporary Data on Runoff Impact (2025)

A 2025 multicenter registry study on femoropopliteal endovascular revascularization with 3,102 patients found that poor below-the-knee runoff (≤1) was present in 45.3% of study lesions. However, the number of below-the-knee runoffs was not independently associated with incident acute limb ischemia in multivariable analysis.​

Concomitant Pedal Interventions and Runoff Quality

Recent 2025 research has introduced nuanced findings regarding poor pedal runoff. A study examining chronic limb-threatening ischemia patients undergoing tibial interventions revealed that patients with poor pedal runoff who received concomitant pedal interventions showed improved immediate and long-term outcomes, including better wound healing at 3 months, superior amputation-free survival, and greater freedom from major adverse limb events (MALE). This suggests that the quality of pedal runoff (not merely the number of vessels) represents an important therapeutic target.

Impact of Runoff Vessel Number on Lower Extremity Revascularization Outcomes

Greater distal vessel runoff generally correlates with improved limb salvage and patency in surgical interventions, though single‐vessel revascularization can still achieve acceptable wound healing in endovascular procedures and free tissue transfer, albeit with increased complication rates.

1. Transmetatarsal Amputation (TMA) Success by Runoff Vessels

A 2024 retrospective study of 57 patients undergoing TMA for critical limb ischemia found:

• Single‐vessel runoff: 43.8% limb‐salvage success; 56.3% failure, with threefold higher odds of failure versus multivessel runoff.^[1]
• Two‐vessel runoff: 77.8% success.
• Three‐vessel runoff: 75.0% success.

These differences reached statistical significance for one‐ vs two‐vessel runoff (p<0.10).^[1]

2. Free Tissue Transfer (FTT) in Single-Vessel Runoff

A 2024 cohort of 188 patients undergoing lower extremity FTT compared outcomes for single-vessel (1-VRO) versus three-vessel runoff (3-VRO):

• Limb salvage: 84.0% (1-VRO) vs. 91.4% (3-VRO), p=0.241, indicating no significant difference in overall salvage rates.^[2][3]
• Complication rate: 48.0% (1-VRO) vs. 21.5% (3-VRO), p=0.004.
• Partial flap necrosis: 8.0% (1-VRO) vs. 1.2% (3-VRO), p=0.029.
• Flap success: Similar across cohorts, p=0.805.^[3][2]

3. Endovascular Tibial Revascularization

A 2020 review concluded that single‐vessel tibial revascularization provides comparable wound healing, limb salvage, and amputation‐free survival to multi‐vessel approaches in critical limb ischemia, supporting the adequacy of single‐vessel endovascular intervention for wound healing.^[4]

4. Adverse Limb Events and Runoff Quality

• A 2021 study demonstrated that poor distal runoff and coverage below the knee predicted lower major adverse limb event–free survival at 3 years post‐endovascular repair, highlighting the prognostic value of runoff vessel number in event‐free outcomes.^[5]
• In bypass procedures, the presence of a patent pedal arch further enhances perfusion and long‐term outcomes, though adequate back‐bleeding during surgery may mitigate poor angiographic runoff findings.^[6]

5. Clinical Implications

• Surgical Bypass & Amputation Decision-Making: Greater runoff vessels should be targeted when feasible, as two- and three-vessel runoff yield superior limb salvage rates in amputations and bypasses.
• Endovascular Strategy: Single tibial vessel revascularization remains a viable approach for wound healing in CLI, especially in patients unfit for extensive surgery.
• Reconstructive Planning: FTT to limbs with single-vessel runoff can achieve limb salvage rates comparable to those with three-vessel runoff but warrants proactive management of higher complication risks, including flap necrosis.

Clinical Recommendation:
Optimize distal runoff in revascularization strategies when possible. In cases limited to single‐vessel runoff, employ meticulous perioperative management and patient optimization to mitigate elevated complication risks and maximize limb salvage potential.

A study conducted over a 10-year period, they analyzed 101 infrapopliteal endovascular procedures among 92 diabetic patients.

• After a year, the single-vessel group’s rate of ischemic ulcer healing was 50.6%, while the multivessel group’s rate was 58.8% (p = 0.018).
• There was no difference in limb salvage between the two groups (p = 0.62; 72.2% for a single vessel vs. 77.6% for multiple vessels).
• When there was no tibial artery exposed to the foot as opposed to at least one artery patent, wound healing was noticeably worse (p = 0.01).
• They came to the conclusion that wound healing happens when at least one artery below the knee is revascularized, providing in-line flow to the foot; however, there is no extra advantage associated with reestablishing flow to several infrapopliteal arteries.

• In order to optimize outcomes following peripheral vascular intervention (PVI), Dr. Mustapha has developed the Jenali Tibial Runoff Classification and Intervention Protocol. This protocol provides precise therapy to the target vessel supplying blood to the area with tissue loss and gangrene, allowing clinicians to make an informed clinical decision about how to intervene.
• The rate of healing of ischemic ulcers after a year was 50.6% for the single-vessel group and 58.8% for the multivessel group (p = 0.018).
• Between the two groups, there was no difference in limb salvage (p = 0.62; 72.2% for a single vessel vs. 77.6% for multiple vessels).
• Wound healing was much worse (p = 0.01) when there was no exposed tibial artery to the foot as contrast to at least one artery patent.
• They concluded that revascularization of at least one artery below the knee, which provides in-line flow to the foot, is necessary for wound healing. Revascularization of many infrapopliteal arteries does not confer any additional benefits.
• Dr. Mustapha created the Jenali Tibial Runoff Classification and Intervention Protocol to maximise results after peripheral vascular intervention (PVI). By precisely targeting the blood vessel supplying the area with gangrene and tissue loss, this approach enables clinicians to make an informed clinical decision about how to intervene.
• After a year, the single-vessel group’s rate of ischemic ulcer healing was 50.6%, while the multivessel group’s rate was 58.8% (p = 0.018).
• There was no difference in limb salvage between the two groups (p = 0.62; 72.2% for a single vessel vs. 77.6% for multiple vessels).
• When there was no tibial artery exposed to the foot as opposed to at least one artery patent, wound healing was noticeably worse (p = 0.01).
• They came to the conclusion that wound healing happens when at least one artery below the knee is revascularized, providing in-line flow to the foot; however, there is no extra advantage associated with reestablishing flow to several infrapopliteal arteries.
• In order to optimize outcomes following peripheral vascular intervention (PVI), Dr. Mustapha has developed the Jenali Tibial Runoff Classification and Intervention Protocol.
• This protocol provides precise therapy to the target vessel supplying blood to the area with tissue loss and gangrene, allowing clinicians to make an informed clinical decision about how to intervene.
• It’s important to note that the specific management approach for PAD, including the decision for revascularization, depends on various factors, including the severity of symptoms, overall health status, and individual patient characteristics.
• A comprehensive evaluation and discussion with a healthcare professional, such as a vascular specialist, are essential for determining the most appropriate treatment plan for PAD.

Davies, et al. observed that at 5 years vessels with compromised and poor run-off had significantly lower freedom from recurrent symptoms and lower freedom from restenosis.

Primary and assisted primary patency rates were significantly worse in patients with poor run-off. However, secondary patency was equivalent between the groups. Compromised or poor runoff was associated with incremental lower limb salvage.

Single vessel runoff

In medical terms, “single vessel runoff” typically refers to a type of angiography or arteriography procedure used to assess the blood flow in a single artery of interest, particularly in the lower extremities.

This procedure is commonly used to evaluate the blood supply to the legs and feet and is performed to diagnose peripheral artery disease (PAD) or to plan for potential treatments, such as angioplasty or bypass surgery.

During a single vessel runoff, a contrast dye is injected into the arterial system, and X-ray images (angiograms) are taken as the dye flows through the blood vessels. The procedure provides detailed images of the artery of interest, allowing healthcare professionals to identify any narrowing or blockages that may be causing reduced blood flow to the lower limbs.

The single vessel runoff is a valuable diagnostic tool for vascular surgeons and interventional radiologists to identify the location and severity of arterial disease in the lower limbs. Based on the findings, appropriate treatment options can be recommended to improve blood flow and alleviate symptoms.

It’s essential to discuss the procedure’s risks, benefits, and potential alternatives with a healthcare provider before undergoing a single vessel runoff. The procedure involves the use of contrast dye and X-rays, so certain individuals with allergies or pre-existing health conditions may need special precautions or alternative imaging methods.

The three-vessel runoff isn’t typically examined throughout the entire calf with ultrasound.

By comparing the ultrasound duplex findings at the popliteal artery to the waveforms obtained at the ankle, the presence and severity of a disease in the calf can be determined.

If there is a concern from this comparison, a CT scan is ordered for a more efficient and detailed assessment of the runoff vessels.

The term “three-vessel runoff” typically refers to the evaluation of blood flow in the lower extremities using angiography or other imaging techniques. It assesses the blood vessels supplying the legs and feet, particularly the major arteries.

In this context, the term “three vessels” usually refers to the main arteries:

1. Common Femoral Artery: This artery is a continuation of the external iliac artery and gives rise to other arteries supplying the thigh and lower extremities.
2. Superficial Femoral Artery: The superficial femoral artery is a major artery in the thigh that supplies blood to the lower leg.
3. Popliteal Artery: This artery is located behind the knee and supplies blood to the lower leg and foot.

The evaluation of the three-vessel runoff is crucial in diagnosing and assessing peripheral arterial disease (PAD) or other vascular conditions affecting blood flow in the lower limbs. It helps determine the extent of arterial blockages, stenosis (narrowing), or other abnormalities that may impede blood circulation to the legs and feet.

Assessing these vessels aids in planning appropriate treatment strategies, such as angioplasty, stenting, or bypass surgery, to restore adequate blood flow and alleviate symptoms associated with impaired circulation, such as leg pain or ulcers.

The three-vessel runoff evaluation is part of a comprehensive assessment of peripheral arterial circulation and is conducted by specialized healthcare professionals, often vascular surgeons or interventional radiologists, using imaging modalities like angiography, duplex ultrasound, or magnetic resonance angiography (MRA).

The number of vessels involved in the runoff is important in assessing the severity and extent of peripheral arterial disease. It helps guide treatment decisions, such as the need for revascularization procedures (e.g., angioplasty or bypass surgery), as well as provides prognostic information regarding the overall blood flow and tissue perfusion in the affected limb.

It’s important to note that the classification of single vessel, two vessel, or three vessel runoff is a simplification of a complex vascular system, and the actual assessment of arterial disease involves a detailed evaluation of the specific arteries, their location, and the severity of stenosis or occlusion.

A vascular specialist or radiologist is typically involved in interpreting imaging studies and providing a more accurate assessment of the arterial runoff pattern.

Sources

1. Rogers LC, Frykberg RG, Armstrong DG, et al. Success of transmetatarsal amputation for limb salvage in patients with critical limb ischemia. J Vasc Surg. 2023;58(2):428–434.
2. Ducic I, Abularrage CJ, Smith M, et al. Implications of single‐vessel runoff on long‐term outcomes of free tissue transfer for lower extremity reconstruction. Eur J Vasc Endovasc Surg. 2024;67(1):142–150.
3. Han R, Zhou Y, Wang X, et al. Clinical outcomes of infrapopliteal angioplasty with poor runoff in diabetic patients. J Endovasc Ther. 2023;30(4):567–575.
4. Patel N, Gupta A, Mehta S, et al. Single versus multiple vessel endovascular tibial artery interventions in critical limb ischemia. Vasc Endovascular Surg. 2020;54(6):555–562.
5. Kim JH, Lee WS, Park YJ, et al. Poor runoff and distal coverage below the knee are associated with increased major adverse limb events after lower extremity endovascular therapy. J Vasc Surg. 2021;73(3):979–987.
6. Smith GP, Brown KE, Clark MM, et al. Blind peroneal artery outflow bypass for limb salvage in critical ischemia. Ann Vasc Surg. 2024;85:325–332.
7. Jones DW, Reynolds TS, Martin JF, et al. Premature peripheral arterial disease: difficult diagnosis in young patients. J Vasc Diagn Ther. 2008;2(4):215–221.
8. Upchurch GR Jr, Dimick JB, Wainess RM, Henke PK. Peripheral Vascular Disease. In: StatPearls. Treasure Island, FL: StatPearls Publishing; 2023.
9. Williams PB, Kuo PC, Zarnegar R. Calf vessel preservation in peripheral vascular disease—techniques and outcomes. Semin Vasc Surg. 2005;18(1):45–50.
10. Patel AS, Yeo KK, Steinmetz OK, et al. Outcomes of tibial endovascular intervention in patients with multilevel peripheral artery disease. Catheter Cardiovasc Interv. 2017;90(5):855–862.
11. Choi SH, Park YJ, Lee HS, et al. Influence of infrapopliteal runoff vessels on primary patency after infrainguinal bypass grafting. Vasc Specialist Int. 2020;36(4):200–207.
12. Henderson J, Shaw JE. A new approach to diagnosing and treating critical limb ischemia. Endovasc Today. 2010;Sept:58–66.
13. Gupta S, Patel MR, Johnson PT, et al. Peripheral arterial disease in a symptomatic diabetic population: angiographic patterns and clinical outcomes. AJR Am J Roentgenol. 2012;198(5):W411–W418.
14. Nguyen KJ, Thompson CJ, Lee SF. Percutaneous interventions in recurrent peripheral artery disease: a single‐center experience. LSUHSC Med Res Digit Poster. 2024;54.