Femoral Artery Cut-Down and Proximal Anastomosis Procedure (Cadaver)

Abstract

Femoral-to-popliteal/distal bypass surgery is a procedure used to treat femoral artery disease. It is performed to bypass the narrowed or blocked portion of the main artery of the leg, redirecting blood through either a transplanted healthy blood vessel or through a man-made graft material. This vessel or graft is sewn above and below the diseased artery such that blood flows through the new vessel or graft. The bypass material used can be either the great saphenous vein from the same leg or a synthetic polytetrafluoroethylene (PTFE) or Dacron graft. Blockage is due to atherosclerosis that causes peripheral vascular disease. This procedure is recommended for patients with peripheral vascular disease for whom medical management has not improved symptoms, for those with leg pain at rest that interferes with quality of life and ability to work, for non-healing wounds, and for infections or gangrene of the leg where there is a danger of loss of limb caused by decreased blood flow. Here we demonstrate how to perform femoral artery cut-down and proximal anastomosis procedure in a cadaver. This procedure is commonly used when performing a femoral-popliteal below the knee bypass to restore blood flow to areas affected by arterial blockages or injuries․

Keywords

Peripheral arterial disease; revascularization, femoropopliteal bypass, intermittent claudication, peripheral vascular disease.

Case Overview

Background

Peripheral arterial and aortic diseases (PAAD) is estimated to affect around 113 million people aged 40 and over globally, of whom nearly half (43%) are in low- and middle-income countries. The global prevalence is 1.5% and increases with age.¹⁶ The most common cause of peripheral artery disease is atherosclerosis; less common causes include inflammatory disorders of the arterial wall (vasculitis) and noninflammatory arteriopathies, such as fibromuscular dysplasia.¹⁴ Peripheral artery disease can be categorized into two main types: proximal disease, affecting the aortoiliac and femoropopliteal regions, and distal disease, which impacts the infrapopliteal area.¹⁵

Femoral-to-distal artery bypass is a means of revascularization to reverse the symptoms of PAD. Placement of a non-autogenous conduit between the superficial femoral artery (SFA), above the occlusion, and a distal artery restores adequate blood flow. This allows the healing of ulcers, decreases claudication, and normalizes the ankle-brachial index (ABI).

Focused History of the Patient

SFA stenosis due to atherosclerosis leads to PAD, which can be asymptomatic or may have classic symptoms of claudication or may have leg discomfort that is atypical for claudication.¹⁷ Claudication typically felt in the calves, thighs, buttocks, or feet during exercise. The pain can be described as aching, cramping, or a sense of fatigue. Initially, patients can present with pain, cramping, or weakness in the affected limb during exercise that improves upon rest. As atherosclerosis worsens, the pain will present during rest. A subgroup of patients may present with acute or chronic critical limb ischemia. Chronic limb-threatening ischemia (CLTI) is a severe stage of peripheral artery disease (PAD).It is a severe chronic PAD presentation and underlies poor limb outcomes without intervention It involves significantly reduced blood flow to the limbs, leading to various serious symptoms, including severe pain that often occurs at rest and typically worsens at night. This pain can be persistent and may not be relieved by rest. Other symptoms include cold and numb limbs with a tingling sensation, pale, shiny, smooth, and hairless skin, non-healing wounds, and weak or absent pulses. Patients with CLTI often have ulceration or gangrene of the toes on examination. Other symptom patients may present with is muscle atrophy.^14,16

Common risk factors are divided into two groups: traditional and non-traditional. Traditional common risk factors include smoking, hypertension, diabetes mellitus, high level LDL-C, age, sex and polygenic inheritance. Non-traditional risk factors include overweight, sedentary lifestyle, sleep disorders, stressful lifestyle, alcohol, diet, environmental status, high levels of inflammation markers and thrombosis, elevated lipoprotein(a) and homocysteine levels, chronic kidney disease, and autoimmune disease. Female specific risk factors include menopause, pregnancy induced hypertension/diabetes.^14,16 The classic symptom of intermittent claudication only presents in approximately 10% of patients with PAD with ~50% of patients complaining of other various leg symptoms.¹

Physical Exam

Pulse palpation, femoral, carotid, and abdominal bruit auscultation, heart auscultation, and observation of the legs and feet need to be part of the vascular examination.¹⁶ Physical exam can reveal a discolored and cool extremity, decreased distal pedal pulses, chronic non-healing wounds, and bruit over the affected artery. Findings of an abnormal capillary refill should be followed by the Buerger’s test in which the patient’s foot is elevated to 45 degrees, and pallor will present due to decreased arterial supply. Other symptoms that may be present are hair loss, toenail color change, and possibly gangrene.

There are various questionnaires designed to evaluate different aspects of patient-reported outcome measures (PROMs), including functional, mental, and social status.¹⁶

Noninvasive Arterial Testing in the Legs

Noninvasive testing includes the measurement of ankle brachial index, segmental blood pressures, as well as Dopler waveform analysis treadmill testing.

Treadmill testing, following standardized criteria, is the gold standard for assessing walking performance. Patients walk until maximal pain to determine the maximal walking distance (MWD) and indicate when pain begins to define the pain-free walking distance (PFWD). The six-minute walk test (6MWT) assesses functional walking performance. For lower-limb strength, isokinetic dynamometry and the Short Physical Performance Battery (SPPB) test, both with good test-retest reliability, should be used.¹⁶

The ankle-brachial index (ABI) is a low-cost, widely used tool for diagnosing and monitoring PAD, both at rest and after exercise. Resting ABI has a sensitivity of 68–84% and a specificity of 84–99% for PAD diagnosis. An ABI ≤0.90 confirms PAD, while values >1.40 indicate ‘noncompressible arteries.’An ABI >1.40, often seen in conditions like diabetes, severe kidney failure, or advanced age, is associated with higher cardiovascular events and mortality risk. For ABI >1.40, assessing the resting toe-brachial index (TBI) is recommended.^14,16

Measurement of the ABI is recommended as the first line test for screening and diagnosis of PAD. In the case of non-compressible ankle arteries or ABI>1.40 toe-brachial index, TcPO2 or Doppler waveform analysis are recommended.¹⁶

Imaging methods

Duplex ultrasonography, which combines ultrasound and Doppler imaging, is a cost-effective and accessible method for visualizing atherosclerotic plaque in peripheral arteries. Duplex ultrasound is recommended as the first-line imaging method for PAD screening and diagnosis.  It is also frequently used to evaluate the patency of stents or grafts following revascularization. Conventional angiography is recommended for symptomatic patients being considered for revascularization. CTA and/or MRA are recommended as adjuvant imaging. CTA provides better spatial resolution and calcification visualization but may overestimate stenosis due to the blooming effect. MRA allows assessment of arterial walls, lumen, and tissue perfusion around the arterial territory.^{14, 16}

Natural History

As atherosclerosis worsens, PAD symptom severity progresses. There are two commonly used systems of classification:

Rutherford Classification:¹⁰

• Stage 0 – Asymptomatic
• Stage 1 – Mild claudication
• Stage 2 – Moderate claudication
• Stage 3 – Severe claudication
• Stage 4 – Rest pain
• Stage 5 – Ischemic ulcer
• Stage 6 – Severe ischemic ulcers or frank gangrene

Fontaine Classification:¹⁰

• Stage I – Asymptomatic
• Stage IIa – Intermittent claudication after walking distance of > 200 m
• Stage IIb – Intermittent claudication after walking distance < 200 m
• Stage III – Pain at rest
• Stage IV – Ischemic ulcers or Gangrene

Recently the Society for Vascular Surgery (SVS) Lower Extremity Guidelines Committee created a new classification system for threatened limbs. It is based around the wound, ischemia, and foot infections criteria.¹¹

• Grade 0 – ABI >0.80, Ankle systolic pressure >100 mmHg, Toe pressure (tcpO2) >60 mmHg
• Grade 1 – ABI 0.6–0.79, Ankle systolic pressure 70–100 mmHg, tcpO2 40–59 mmHg
• Grade 2 – ABI 0.4–0.59, Ankle systolic pressure 50–70 mmHg, tcpO2 30–39 mmHg
• Grade 3 – ABI <0.39, Ankle systolic pressure <50 mmHg, tcpO2 <30 mmHg

Options for Treatment

Patients with PAD should receive optimal medical treatment. Prior to severe claudication, lifestyle changes such as smoking cessation, healthy diet, weight loss, supervised exercise training, and management of risk factors such as antihypertensive drugs, cholesterol lowering drugs, optimal glucose control, and antithrombotic drugs can reduce complications and progression of atherosclerosis.¹⁶

Revascularization is recommended when symptoms persist despite exercise and medical therapy, and there’s a good chance of symptom relief (excluding other conditions like heart failure or lung disease). It’s also indicated for limb salvage in critical limb ischemia.

Revascularization procedures include endovascular procedures (balloon angioplasty, balloon-expandable stent), endarterectomy, bypass procedures (axillofemoral, femoral-femoral, femoral-popliteal, femoral distal). Endovascular procedures in the superficial femoral artery often result in high restenosis rates. Various technologies, such as drug-eluting stents, covered stents, and drug-coated balloons, are currently under evaluation to reduce these rates. Surgical bypass is recommended when endovascular approaches fail or are not feasible. Aortofemoral bypass is effective for aortoiliac disease, with up to 90% patency at 5 years. For patients unsuitable for surgery, an axillary–femoral graft can be used. Endarterectomy is preferred for common femoral-artery lesions. The saphenous vein is ideal for infrainguinal bypass, while a prosthetic conduit can be used for femoral–popliteal bypass if the above-knee popliteal artery is targeted. Femoral–tibial bypass is an option for critical limb ischemia with infrapopliteal disease.¹⁴

An alternative treatment to bypass is percutaneous transluminal angioplasty (PTA) with or without stenting, which is a minimally-invasive surgery.

Recent medical advancements have led to the development of new tools for treating advanced disease. Despite these advancements, open surgical bypass retains its significance. The selection of an appropriate technique depends on the clinical presentation and the severity of the lesion. PTA, being less invasive, ensures a rapid recovery, however, its efficacy may be compromised in cases of severe blockages. On the contrary, femoral-to-distal bypass, despite being more invasive and having a prolonged recovery period, proves to be an efficacious solution for severe blockages. Consequently, the choice between PTA and bypass depends on the severity of the blockage and the patient's overall condition.

Additionally, after bypass or PTA, a supervised exercise program has been shown to be efficacious in improving walking distance.² If PAD has progressed to severe ischemic ulcers or gangrene, then amputation is performed.

Rationale for Treatment

Femoral-to-distal artery bypass will restore adequate blood flow to the affected extremity. Proper tissue perfusion will decrease pain, weakness, and numbness in the lower extremity. Resolution of claudication allows the patient to resume physical activities. Proper healing of wounds and normal hair growth resume once blood flow is restored.

Discussion

PAD affected more than 113 million people worldwide aged 40 and older, of which 42.6% was in countries with low to middle Socio-demographic Index (SDI). PAD prevalence rose by 72% from 1990 to 2019, considering a 45% growth rate in the world population.³

There are multiple routes to treatment depending on disease severity and location of the blockage. In this article, a femoral-to-distal artery bypass with a Dacron graft was performed. 

Patency is a measure to determine if revascularization needs to be performed again. In below the knee bypasses, Dacron compared to other grafts such as autologous, polytetrafluoroethylene (PTFE) with and without vein cuff, human umbilical vein (HUV), and polyurethane (PUR) showed no differences in primary patency years after the operation.⁴ However, in above the knee bypasses, autologous vein grafts demonstrated better primary patency compared to prosthetic grafts. Of the prosthetic grafts, Dacron without external support had better primary patency rates 24 months later.⁴ In below the knee bypasses, any choice of graft would be appropriate, but with above the knee bypasses, an autologous vein graft has proven to be more beneficial long term.

Endoscopy has helped advance the field of vascular surgery and has been applied to harvesting veins for bypasses. In addition to an endoscopic vein harvest (EVH), there is an open vein harvest (OVH). While EVH is less invasive and seems beneficial, OVH of the greater saphenous vein had higher rates of primary patency after 5 years, but secondary patency was not significantly better than EVH.⁵ While OVH has shown significantly better primary patency rates, there is an increase in the incidence of surgical site infections at the arterial incision site.⁵

Choice of procedure for harvesting should be determined on a case-by-case basis, and surgical site infections can be managed with antibiotics.

Traditionally, bypass has proven to be more efficacious in long-term primary patency.⁶ Recent studies have shown primary patency is better in patients who underwent PTA with stenting compared to traditional femoral artery bypass.⁷ The choice between PTA or femoral-popliteal/distal artery bypass is dependent on the patient, their risk factors, and how advanced their disease is. Bypass is associated with an increased incidence of superficial wound infections and longer length of stay.⁸ Despite the perioperative complications, more bypass patients were free from symptoms 4 years later.⁸ While bypass patients have greater freedom from symptoms, reintervention rates were similar between patients who underwent PTA and patients who underwent bypass.⁸ Endovascular treatments may be highly effective, but traditional bypass surgery is just as efficacious.

Revascularization and vein harvesting can be done endoscopically or open, and many factors play into the route chosen. Attempts at combining open and endovascular techniques have been done for the revascularization of diabetic patients with gangrene. A combined intraoperative balloon angioplasty (IBA) of the SFA with distal bypass graft showed similar perioperative graft failures, mortality rates, and 2-year patency rates compared to the femoral-distal bypass graft and the popliteal-distal bypass graft.⁹ 

Following an uncomplicated femoral-to-distal bypass surgery, the rehabilitation process is typically marked by several milestones. Patients are generally able to sit for the first time after approximately 1.7 days. The ability to walk independently is usually achieved around the 5.7-day mark, provided there are no major adverse events. The first supervised exercise session typically occurs around 6.9 days postsurgery. On average, the length of the hospital stay for such patients is about 19.2 days. This timeline provides a general guide for patients and healthcare providers in managing recovery expectations after this type of surgery.¹³

Disclosures

Nothing to disclose.

Equipment

PTFE graft.

Statement of Consent

Massachusetts General Hospital has given its consent for the cadaver referred to in this video to be used for the education of healthcare professionals and is aware that information will be published online.