Vascular surgery procedures and endovascular repair

• Vascular surgery has moved from open cut-and-sew operations to a hybrid world in which most patients receive an endovascular or hybrid procedure; open surgery is still used when anatomy or durability demands it.
• For an unruptured abdominal aortic aneurysm (AAA), repair is considered when it reaches 5.5 cm on ultrasound, or is larger than 4.0 cm and grows by more than 1 cm in a year, or is symptomatic. The first choice is usually open repair; endovascular aneurysm repair (EVAR) is offered when anatomy or patient risk favors it. ^[1]
• Carotid endarterectomy (CEA) is the operation for atherosclerotic narrowing at the carotid bifurcation. It is strongly indicated for 70 to 99 per cent symptomatic stenosis, and considered for 60 to 99 per cent asymptomatic stenosis with a high-risk plaque or high predicted stroke risk, ideally within 14 days of symptoms. ^[5][6][7]
• Bypass grafts use the patient's own saphenous or arm vein whenever possible; angioplasty and stents are common endovascular treatments for focal arterial narrowing.
• Amputation is a planned, reconstructive step in vascular care: the level is chosen to remove all non-viable and infected tissue while leaving a limb that can heal and be fitted with a prosthesis.
• EVAR needs lifelong surveillance because the aneurysm sac can re-pressurise; an endoleak is found on imaging in many patients, and management depends on its type. ^[1]

By the end of this page you should be able to:

1. Decide when an asymptomatic AAA should be repaired, and explain how open repair and EVAR differ in selection, steps and follow-up.
2. Classify an endoleak by type and state which ones usually need intervention.
3. Explain the indications for carotid endarterectomy, the timing window and the procedure, and where carotid stenting fits.
4. Describe the principles of bypass graft choice (conduit, site of anastomosis, autogenous versus prosthetic) and the role of angioplasty and stents in peripheral artery disease.
5. List the levels at which a lower limb is amputated and the reasoning behind selecting each.
6. Compare the editions of the ESVS, SVS and ACC/AHA guidelines that frame these decisions, and state where they disagree.

Vascular surgery treats the blood vessels outside the heart and brain: the aorta and its branches, the carotid and vertebral arteries, the visceral and renal arteries, and the arteries and veins of the limbs. A modern vascular surgeon does open operations, endovascular procedures, and hybrid combinations of the two. This page surveys the core procedures a medical student meets: aneurysm repair (open and endovascular), bypass grafting, angioplasty and stenting, carotid endarterectomy, and amputation. It draws on the current ESVS, SVS and ACC/AHA guidelines and on NICE guidance, naming the editions it uses. A cardiology topic covers aortic aneurysm as a cardiovascular disease and a separate cardiology topic covers peripheral arterial disease; this page takes the surgical and endovascular view of the same conditions.

• Aorta. The abdominal aorta is infrarenal in most aneurysms: the neck between the renal arteries and the aneurysm is what allows a stent graft to seal. The common and external iliac arteries must also be healthy enough to take the graft limbs.
• Carotid bifurcation. The common carotid splits at about the level of the fourth cervical vertebra into the external carotid (branches to face and neck) and the internal carotid (no branches in the neck, supplies the brain). The carotid bulb is where plaques form.
• Lower limb runoff. The femoral, popliteal and tibial (anterior tibial, posterior tibial, peroneal) arteries determine whether a bypass has a target vessel and how long the graft must be.
• Amputation anatomy. Levels are chosen by bone, muscle, nerves and skin flaps, plus the prosthetic joint above or below the knee.

Every vascular procedure follows the same preparation:

1. Image the whole tree. Duplex ultrasound is first; CTA or MRA gives the detail needed for graft planning and stent sizing. For carotid disease, stenosis is graded by the NASCET method (residual lumen against the normal distal internal carotid artery) or ECST method; about 50 per cent NASCET corresponds to about 70 per cent ECST and 70 per cent NASCET to about 82 per cent ECST. ^[5]
2. Assess cardiovascular risk. Vascular patients usually have coronary and cerebrovascular disease; exercise testing, echocardiography and renal function guide fitness for open surgery.
3. Antithrombotic plan. Continue antiplatelet therapy where indicated, hold or bridge anticoagulants, and plan postoperative antiplatelet and statin therapy.
4. Consent. Discuss open versus endovascular options, the chance of re-intervention, conversions, infection, bleeding, nerve injury and, for aneurysm repair, the risk of spinal cord ischaemia after thoracic or complex repairs.

An abdominal aortic aneurysm (AAA) is a localised dilatation of the abdominal aorta. Screening programmes detect them in men aged 66 years or older; they are far less common but more likely to rupture in women. Risk factors are smoking, hypertension, dyslipidaemia, family history and other atherosclerotic disease. ^[1][2]

NICE NG156 frames the decision clearly. Consider repair for an unruptured AAA when it is symptomatic, when it is larger than 4.0 cm and has grown by more than 1 cm in one year, or when it is 5.5 cm or larger on ultrasound. People with an AAA of 3.0 to 5.4 cm are seen within twelve weeks and enter ultrasound surveillance; those with 5.5 cm or more are referred to a regional vascular service within two weeks. ^[1]

Women have a higher rupture risk at smaller diameters, and other guidelines set a lower operative threshold in women; NICE uses 5.5 cm for everyone. ^[1]

Open repair through a midline or transverse laparotomy removes the aneurysm and replaces it with a tube or bifurcated prosthetic graft sutured to the aortic neck proximally and to the iliac arteries (or aorta) distally. It is durable, avoids aortic clamping above the aneurysm in an infrarenal repair, and has no endoleak, but it is a major laparotomy with higher early cardiopulmonary morbidity. NICE recommends offering open repair for unruptured AAAs meeting the criteria, unless abdominal copathology, anaesthetic risk or comorbidity makes it unsafe. ^[1]

Key points of the operation:

• Exposure and control. The aorta is exposed and clamped; the aneurysm sac is opened and back-bleeding lumbar and inferior mesenteric arteries are oversewn.
• Graft choice. A straight tube graft when both iliac arteries are healthy; a bifurcated aorto-bi-iliac or aorto-bifemoral graft when the iliac arteries are aneurysmal or occluded.
• Perfusion of the pelvis and colon. The inferior mesenteric artery is reimplanted when the colon is at risk; care is taken not to embolise atheroma down the iliacs.
• Adjuncts. Epidural analgesia in addition to general anaesthesia is considered for pain relief after open repair. ^[1]

EVAR places a fabric-and-metal stent graft inside the aorta through the femoral arteries, sealing in the healthy neck below the renal arteries and landing in the iliac arteries. The aneurysm is excluded from pressure but is left in place. It avoids laparotomy and has lower perioperative mortality, so it suits patients with significant comorbidity or a hostile abdomen (previous multiple laparotomies, horseshoe kidney, a stoma). Standard (infrarenal) and complex (fenestrated, branched, customised or physician-modified) devices exist; complex EVAR is reserved for cases where open repair is unsuitable or after full discussion, because long-term benefit is still uncertain. ^[1][2]

Trade-offs:

• Advantages. Less pain, shorter stay, less early morbidity, and usable in high-risk patients.
• Disadvantages. Device costs, lifelong surveillance imaging, the need for suitable neck and iliac anatomy, a higher rate of re-intervention, and the risk of endoleak.

For a ruptured infrarenal AAA, either endovascular or open repair may be used. EVAR gives more benefit than open repair for most patients, especially men over 70 and women of any age; in men under 70, open repair probably gives the better balance of benefit and harm. Complex EVAR is not offered for rupture unless open repair is unsuitable. ^[1]

EVAR needs lifelong surveillance because the aneurysm sac can re-pressurise. All patients enter a surveillance imaging programme with the frequency set by their risk of complications. Contrast-enhanced CT angiography is used if an endoleak is suspected; duplex ultrasound alone cannot exclude one. ^[1]

An endoleak is persistent blood flow outside the stent graft but inside the aneurysm sac. There are five types: ^[1]

• Type 1: an ineffective seal at either end of the graft. ^[1]
• Type 2: flow from aortic side branches such as the lumbar or inferior mesenteric artery. ^[1]
• Type 3: a defect in the graft fabric or a junction leak.
• Type 4: perfusion through the fabric of the graft. ^[1]
• Type 5: continued sac expansion with no visible leak (endotension). ^[1]

Management differs by type: type 1 and type 3 are treated (open, endovascular or percutaneous) because they pressurise the sac directly; type 2 is treated only when the AAA expands; type 5 needs further investigation. ^[1]

The ESVS 2024 guideline for abdominal aorto-iliac aneurysms organises 160 recommendations across screening, surveillance, elective and ruptured repair, complex disease, iliac aneurysms and follow-up, and is the most comprehensive current European statement on this topic. ^[2]

Atherosclerotic stenosis of the internal carotid artery at the bifurcation is a major cause of ischaemic stroke, roughly 10 to 15 per cent of all strokes. It may be asymptomatic or present with a transient ischaemic attack or minor stroke. Management starts with optimal medical therapy for everyone: smoking cessation, an antiplatelet drug, a statin to an LDL-cholesterol target, blood pressure control, diabetes control and lifestyle change. ^[5]

Current guideline positions, as summarised in recent reviews:

• Symptomatic stenosis. Revascularisation is recommended when stenosis exceeds 50 per cent by the NASCET method, with a strong recommendation for 70 to 99 per cent and a weaker one for 50 to 69 per cent. Stenosis below 50 per cent is not treated surgically. ^[5][6][7]
• Asymptomatic stenosis. Consider intervention when stenosis exceeds 60 per cent provided life expectancy is at least 2 to 5 years and the patient has increased stroke risk on medical therapy alone. ^[5]
• Timing. The absolute benefit of surgery is greatest within 14 days of the index event; both ESVS and SVS recommend revascularisation within 14 days in appropriate patients. Surgery should be avoided in disabling stroke, infarction involving more than 30 per cent of the ipsilateral middle cerebral artery territory, a modified Rankin score of 3 or more, or reduced consciousness. ^[5][6][7]
• Procedural safety thresholds. Periprocedural stroke or death should be below 2 per cent for asymptomatic and 4 per cent for symptomatic disease, stricter than the historical 3 per cent and 6 per cent, reflecting modern techniques and medical therapy. ^[5]
• Revascularisation within 14 days should be by endarterectomy rather than transfemoral stenting, because early stenting has a higher periprocedural stroke risk, especially in patients older than 70 years. ^[5][6]

Carotid endarterectomy is performed through a neck incision along the sternocleidomastoid. The carotid artery is exposed and clamped (or shunted) and the atheromatous intima and media are removed en bloc; the artery is closed primarily or with a patch. The operation is performed under general or regional anaesthesia with cerebral monitoring. CAS (carotid artery stenting, including transcarotid artery revascularisation) is the endovascular alternative, reserved for patients with anatomy or comorbidity that favours it; transcarotid approaches now give lower periprocedural stroke rates than transfemoral stenting in some registries. ^[5][6][7]

Carotid duplex ultrasound grades severity with velocity criteria. PSV, EDV and ICA/CCA ratios are used together with B-mode imaging and the 70 to 99 per cent category is confirmed by CTA, MRA or angiography. The thresholds below come from the multiparametric criteria summarised in the recent review literature. ^[5]

Modern guidelines increasingly look at plaque vulnerability (intraplaque haemorrhage, ulceration, silent infarction, stenosis progression, microembolic signals) as well as stenosis. In 60 to 99 per cent asymptomatic stenosis, ESVS recommends considering endarterectomy (class IIa) if imaging shows a high-risk plaque feature, life expectancy exceeds 5 years and the documented 30-day stroke or death rate is below 3 per cent. ^[5][7]

Carotid artery stenting (transfemoral) is anatomically demanding because the catheter crosses the aortic arch. Modern stents are often mesh-covered to reduce plaque prolapse, and proximal flow-reversal protection (TCAR, transcarotid artery revascularisation) reduces embolic risk in older patients by bypassing the aortic arch. TCAR is now preferred to transfemoral stenting where an endovascular approach is already indicated, but no randomised trial has shown it superior to endarterectomy. ^[5][6]

Carotid atherosclerosis accounts for about 10 to 15 per cent of all strokes. Prevalence rises with age: in population studies, stenosis above 50 per cent affects 0.2 to 3.1 per cent of women and 0.1 to 3.1 per cent of men, and stenosis above 70 per cent affects 0.1 to 1.7 per cent of women and 0.1 to 2.3 per cent of men, depending on age group. About 14 to 19 per cent of patients with peripheral arterial disease have carotid stenosis. ^[5]

CREST-2 randomised 1,245 patients in its stenting trial and 1,240 in its endarterectomy trial with asymptomatic carotid stenosis of at least 70 per cent. At 4 years the composite primary endpoint was 6.0 per cent with medical therapy alone versus 2.8 per cent with stenting, an absolute difference of 3.2 percentage points and a number needed to treat of 31. In the endarterectomy trial the endpoint was 5.3 per cent with medical therapy alone versus 3.7 per cent with endarterectomy, which did not reach statistical significance. Medical therapy has improved so much that stenting, not endarterectomy, produced the statistically significant benefit in this trial. These data favour selective, individualised revascularisation on top of optimised medical therapy rather than routine surgery for every asymptomatic stenosis. ^[5]

A bypass carries blood around an arterial occlusion from a healthy inflow vessel to a healthy outflow vessel distal to the disease. The indications are functionally limiting claudication despite best medical therapy and all threatened-limb (CLTI) disease. The operation is combined with endarterectomy or hybrid endovascular techniques when needed. ^[4]

The conduit is the most important decision in lower-limb bypass. Autogenous vein, usually the great saphenous, should be the first choice when available because it has clearly and consistently better primary patency than prosthetic material for femoropopliteal and infrapopliteal bypass. Prosthetic grafts (PTFE/Dacron) perform well for aorto-iliac reconstruction and are used when no vein is available for tibial bypass. Preoperative duplex ultrasound mapping of the great saphenous vein is recommended in patients with CLTI. ^[4]

• Aorto-iliac disease. Aorto-bifemoral or aorto-iliac bypass; prosthetic conduit is acceptable here. Restoration of inflow may be the only revascularisation needed in multilevel disease.
• Femoropopliteal disease. Bypass from the common femoral artery to the above-knee or below-knee popliteal artery, using vein; below-knee anastomosis is technically more demanding and has higher complications.
• Infrapopliteal disease. Tibial or pedal bypass for tissue loss; constructed with autogenous vein only. ^[4]

• Inflow first. Correct aorto-iliac inflow disease before outflow reconstruction.
• Conduit quality. Vein calibre, segment length, previous harvest for coronary surgery and varicose segments all matter.
• Heel and anastomotic configuration. Compliance mismatch at the anastomosis is a cause of intimal hyperplasia and failure.
• Graft surveillance. Postoperative duplex surveillance of vein grafts allows revision before thrombosis.

Angioplasty inflates a balloon inside a narrowed artery to enlarge the lumen; a stent is a metal scaffold that holds it open. They are endovascular, usually access is via the femoral, radial or brachial artery under local anaesthesia and sedation, and they suit focal, short lesions and patients who are poor surgical candidates. ^[4]

• Iliac (aorto-iliac) disease. Angioplasty and stenting of the common and external iliac arteries gives excellent results and is preferred over open bypass in most cases.
• Femoropopliteal disease. Drug-coated balloons and drug-eluting or interwoven nitinol stents have improved durability of above-knee lesions; long calcified occlusions remain difficult.
• Infrapopliteal disease in CLTI. Percutaneous transluminal angioplasty (with or without a stent) of tibial arteries is often preferred in high-risk patients and less complex anatomy; autogenous vein bypass may be preferred in average-risk patients with advanced limb threat and high-complexity disease. ^[4]
• Complex disease. Hybrid procedures (open femoral endarterectomy plus iliac stenting) and atherectomy devices fill the gap in selected patients.

Dual antiplatelet therapy after lower-limb bypass or stenting has uncertain benefit in unselected patients; one subgroup (CASPAR) found clopidogrel plus aspirin reduced major adverse limb events or death after prosthetic, but not autogenous, bypass compared with aspirin alone. Warfarin added to aspirin after bypass increased death in one trial. After angioplasty or stenting of peripheral arteries, antiplatelet therapy is standard. ^[4]

Amputation is a definitive treatment, not a failure. The level is set by three questions: can the tissue heal at this level, will the resulting limb accept a prosthesis, and what is the patient's functional goal and life expectancy. ^[3]

Levels of lower-limb amputation, from distal to proximal:

• Toe and ray amputations: for limited necrosis or infection in a well-perfused foot.
• Transmetatarsal amputation: used when more than two digital rays would be lost, especially when the hallux is involved. ^[3]
• Ankle level (Syme or ankle disarticulation): preserves some weight-bearing and is used when the foot itself cannot be saved but the leg is perfused.
• Transtibial (below-knee): the most common functional major amputation; retains the knee joint and gives the best chance of walking on a prosthesis.
• Knee disarticulation: useful in younger patients and for bilateral amputation.
• Transfemoral (above-knee): when the knee and below-knee tissue cannot be saved; energy cost of walking is much higher.
• Hip disarticulation or hemipelvectomy: for unresectable proximal disease or tumour; rarely rehabilitated to independent walking.

Principles of choosing level: take bone and soft tissue at the most distal level that removes all infection and necrosis; get vascular and wound advice on perfusion with toe pressures; preserve length; and involve a rehabilitation and prosthetics team from the time the decision is made. In CLTI, revascularisation to allow healing at a more distal functional level is preferred when the patient is likely to rehabilitate and walk again. Primary amputation or palliation is appropriate for an unsalvageable limb, poor functional status, or short life expectancy after shared decision-making. ^[3]

The complications common to vascular procedures:

• Endoleak (aneurysm repair): type 1 and 3 are urgent; type 2 is common and usually harmless unless the sac expands. ^[1]
• Graft thrombosis or restenosis: early thrombosis from technical error; late from intimal hyperplasia or atherosclerosis; presents as recurrent claudication, rest pain or a new cold limb.
• Reperfusion injury and compartment syndrome after revascularisation of a severely ischaemic limb.
• Bleeding and haematoma, including retroperitoneal bleeding from femoral access.
• Infection: graft infection is a serious, limb-threatening (and sometimes life-threatening) complication; antibiotic cover and sterile technique matter.
• Nerve injury: femoral, hypoglossal, recurrent laryngeal, vagus and marginal mandibular nerves are at risk during vascular exposures.
• Stroke from carotid or aortic manipulation or embolisation.
• Renal injury from iodinated contrast and cholesterol embolisation.
• Spinal cord ischaemia after thoracic or complex thoracoabdominal repair, mainly with long segment coverage of intercostals.
• Abdominal compartment syndrome after ruptured aneurysm repair.
• Amputation-related complications: phantom limb pain, neuroma, wound breakdown, flexion contractures and poor prosthetic fit.

• AAA. Ultrasound screening and aneurysm diameter thresholds are cheap; repair capacity (open and endovascular) is the limiting factor. NICE-style thresholds can be adopted locally. ^[1]
• Carotid disease. Duplex ultrasound and a reliable endarterectomy service within 14 days deliver most of the benefit; stenting requires more infrastructure. ^[5]
• Bypass and angioplasty. Vein bypass is affordable where an operating team is available; balloon angioplasty alone is cheaper than stenting.
• Amputation. Ensure offloading, infection control and glycaemic control; postoperative rehabilitation often determines whether the patient walks again. ^[3][4]

Where sources disagree (for example on the operative threshold for unruptured AAA in women, and on the role of revascularisation for asymptomatic carotid stenosis after CREST-2), this page states both positions rather than merging them. ^[1][5]