Surgical Decision-Making and Outcomes in Open Versus Endovascular Repair for Various Vascular Diseases

INTRODUCTION

Disease History and Epidemiology

Over the past century, people have been fascinated with the ability to visualize the vascular anatomy. However, it was not until the 1960s that Dr Charles Dotter was able to transition these diagnostic imaging techniques into therapeutic capabilities. The first percutaneous transluminal angioplasty of a femoral artery was performed in 1964,¹ followed by the first endovascular aortic repair (EVAR) by Dr Juan Parodi in Buenos Aires approximately 30 years later. Today, approximately 80% of abdominal aortic aneurysms (AAAs) are treated endovascularly.² As endovascular therapy continues to advance, an increasingly large proportion of the current vascular surgeon’s practice is dedicated to endovascular treatment. However, it is important to acknowledge that open surgical techniques will continue to be necessary for many patients for a wide variety of reasons and to understand the decision-making that goes into selecting an endovascular versus open repair approach.

The Nature of the Problem

With so many treatment options and modalities available to treat patients with vascular disease processes, how is it that vascular surgeons should decide which approach to use? It is important to weigh the pros and cons of endovascular and open techniques when evaluating each patient and to consider the disease process and surgical management they require. Although endovascular intervention has become widely used due to lower rates of periprocedural complications compared with open surgery, there are many circumstances in which an open procedure may be more beneficial.

Overall Considerations

There are certain patient-centered characteristics that should be considered when deciding whether to perform an endovascular or open procedure, regardless of the disease process that is being treated. The patient’s age, frailty, functional status, cardiopulmonary status, and any uncontrolled comorbidities, such as diabetes and hypertension, must be taken into account. Endovascular interventions are typically less physiologically stressful than open operations so may be preferred in patients with more comorbidities, worse frailty, or poor functional status. In contrast, open operations have better longevity than endovascular interventions in many instances, so younger, fitter patients may benefit from a more physiologically stressful operation up front in order to maximize long-term gains.

The availability of a suitable vascular access site is also a critical consideration for any patient being considered for endovascular intervention. The vessel being accessed must have an adequate access point without prohibitive calcification and must have adequate diameter for the planned sheath; this is particularly relevant to women, who tend to have smaller diameter vessels that may not be of adequate caliber to accommodate a large-bore sheath. Access adequacy should be evaluated before any operative decision-making by using appropriate preoperative imaging.

DISCUSSION

Carotid Disease

Disease process and diagnosis

According to the US Centers for Disease Control and Prevention, there are approximately 800, 000 cerebrovascular accidents per year making stroke a leading cause of death and disability in patients older than 65 years.^3,4 Of these cerebrovascular events, 20% can be attributed to large vessel atherosclerotic disease, primarily of the carotid arteries.^3–6 Carotid artery stenosis can be recognized due to symptomatic presentation, or may be asymptomatic and found incidentally on imaging, or as a result of a carotid bruit on physical examination. In patients presenting with neurologic symptoms including stroke, transient ischemic attack, or amaurosis fugax, evaluation for carotid artery stenosis is indicated. Carotid duplex ultrasound is the imaging study of choice for carotid disease and can provide critical information regarding patient anatomy and flow velocity that corresponds to degree of stenosis and plaque characteristics. Duplex ultrasound, however, is limited in its ability to fully characterize calcified plaques and is unable to provide any information regarding intracranial carotid pathology, in which case computed tomographic angiography (CTA) (ideally) or magnetic resonance angiography is helpful. Digital subtraction angiography is reserved for cases in which the aforementioned studies are inconclusive, as it is an invasive imaging modality that is associated with a small risk of stroke.⁵

A brief overview of surgical approaches

Carotid endarterectomy.

Carotid endarterectomy (CEA) is a procedure that directly removes the atherosclerotic plaque causing stenosis from the vessel lumen through an arteriotomy. CEA is the gold standard for management of both symptomatic and asymptomatic carotid occlusive disease. A brief summary of the procedure is as follows:

• The carotid sheath is accessed by a longitudinal incision along the medial border of the sternocleidomastoid.

• The distal common carotid artery, its bifurcation, and the internal and external carotid arteries are isolated, and control of the vessels is obtained proximal and distal to the area of disease.

• The surgeon must then decide whether to shunt blood flow around the area of stenosis to maintain cerebral perfusion through the internal carotid artery (ICA). Some surgeons practice routine shunting, others practice selective shunting, and others practice no shunting; there have been no data to support one approach over another, but consistent practice of one approach is typically favored.

• There are multiple techniques for plaque extraction. The two most described in the literature are the conventional endarterectomy and eversion endarterectomy techniques. In the conventional endarterectomy technique, a longitudinal arteriotomy is made extending from the distal common carotid artery onto the ICA, through which the plaque is elevated and removed. The arteriotomy is then closed with a patch to prevent restenosis. In the eversion endarterectomy technique, the ICA is transected at its origin from the common carotid artery, and the vessel is everted to expel the plaque.⁵

The North American Symptomatic Carotid Endarterectomy Trial (NASCET) was a landmark trial published in 1991 in which medical management alone was compared with medical management plus CEA in patients with symptomatic moderate (30%–69%) and severe (70%–99%) carotid artery stenosis. Patients with severe stenosis were found to have a 17% risk reduction in the incidence of ipsilateral stroke over a 2-year period following CEA compared with medical management alone; and those with moderate stenosis had a 6.5% risk reduction over a 5-year period compared with medical management alone.^5,7 The European Carotid Surgery Trial (ECST) revealed similar results favoring CEA for symptomatic patients over medical management alone (13.5% risk reduction over 3 years among patients with severe stenosis).⁸ The Asymptomatic Carotid Atherosclerosis Study (ACAS) was a randomized controlled trial published in 1995 that evaluated the benefit of medical management alone compared with medical management plus CEA in patients with asymptomatic carotid artery stenosis between 60% and 99%. Patients undergoing CEA had a 5.9% risk reduction for ipsilateral stroke compared with medical management alone over a 5-year period, supporting the use of CEA in patients with asymptomatic carotid stenosis greater than 60%.⁹ There is substantial debate about the contemporary relevance of the ACAS results because the trial was performed before the widespread use of statin therapy, but current professional guidelines still support the use of carotid revascularization for asymptomatic disease.¹⁰

Carotid artery stenting.

There have been many advancements over the past four decades regarding endovascular alternatives for carotid occlusive disease management. In contrast to the carotid endarterectomy, carotid artery stenting (CAS) has been developed as a minimally invasive (endovascular) alternative for treatment of both symptomatic and asymptomatic carotid stenosis.^4,11 Carotid artery stenting was originally described via a percutaneous transfemoral approach (ie, TF-CAS) and was designed as a less invasive approach to carotid revascularization than CEA. The TF-CAS procedure is briefly performed as follows:

• The femoral artery is accessed using a sheath and then wires and catheters are advanced up through the aorta and aortic arch to select the common carotid artery on the affected side.

• Once carotid access is obtained, an embolic protection device is passed distal to the ICA lesion to protect the patient from any microemboli that may be produced during the procedure. Alternatives to the distal ICA filter include a distal ICA occlusive balloon or flow reversal using balloon occlusion of the common carotid artery inflow and the external carotid artery.

• Depending on the lesion characteristics, a balloon angioplasty is performed to allow for stent placement across the lesion. The stent is deployed across the lesion through the same sheath and may require postdeployment balloon angioplasty if the stenosis remains greater than 30%.

Early studies of TF-CAS in patients at high risk for CEA found that the intervention was limited by the high risk of plaque embolization to the brain. With the advent of embolic protection devices, as described earlier, the Stenting and Angioplasty with Protection in Patients at High Risk for Endarterectomy (SAPPHIRE) trial showed that TF-CAS was not inferior to CEA in the management of patients at high risk for CEA.¹² Subsequently, the Carotid Revascularization Endarterectomy versus Stenting Trial (CREST) found that a primary outcome of composite ipsilateral stroke, myocardial infarction, and death did not differ between patients with both symptomatic and asymptomatic carotid artery stenosis who underwent TF-CAS when compared with CEA; however, the risk of perioperative stroke was found to be higher in the TF-CAS group, whereas the risk of myocardial infarction was found to be lower.¹¹ The results from CREST also suggested that older patients (>70 years of age) had a significantly higher risk of stroke with TF-CAS compared with their younger counterparts. Currently, TF-CAS is only for carotid revascularization in patients who are considered high-risk for CEA,¹³ which includes patients with the following:

• Class III or IV congestive heart failure

• Left ventricular ejection fraction less than 30%

• Recent myocardial infarction or unstable angina

• Contralateral carotid artery occlusion

• Recurrent stenosis following endarterectomy

• Previous neck surgery or radiation therapy to the head and neck

• Other conditions that were used to determine patients at high risk for CEA in carotid artery stenting trials such as the SAPPHIRE trial¹²

Transcarotid artery revascularization.

Given the elevated risk of stroke with TF-CAS compared with CEA, transcarotid artery revascularization (TCAR) was developed as an alternative minimally invasive hybrid procedure in which flow in the carotid artery is reversed before stenting in order to protect against distal embolization of debris. Unlike TF-CAS, TCAR avoids manipulation of wires and catheters in the aortic arch, thereby theoretically reducing the risk of perioperative stroke. However, patients undergoing TCAR have to meet several other anatomic criteria (eg, appropriate length of common carotid artery to bifurcation, no common carotid artery disease, noncircumferential lesion calcification) in order to be eligible for the procedure. A brief summary of the steps of TCAR is as follows:

• A small incision is made at the base of the neck through which the common carotid artery is exposed.

• The exposed common carotid artery as well as the femoral vein are canalized and connected via an external filter–containing circuit to facilitate cerebral flow reversal.

• The common carotid artery is clamped proximal to the sheath, and flow reversal is initiated.

• A wire is used to cross the lesion in the ICA, and then a stent is placed across it.

The safety and efficacy of TCAR has been evaluated in the Safety and Efficacy Study for Reverse Flow Used during Carotid Artery Stenting Procedure (ROADSTER) 1 and 2 trials,^14,15 which suggest that TCAR has low rates of stroke and myocardial infarction. Based on data from the Vascular Quality Initiative, TCAR has been shown to be associated with a similar risk of perioperative and 1-year stroke/death and lower risk of myocardial infarction compared with CEA and a lower risk of perioperative stroke/death compared with TF-CAS. Although these data are promising, there are currently no randomized controlled trials (RCTs) comparing outcomes of TCAR with CEA or TFCAS, and long-term outcomes data are lacking.

• Key clinical points

  • CEA is considered the gold standard for carotid revascularization but also has the highest physiologic stress and myocardial infarctions risk compared with other approaches.
  • High-risk characteristics for CEA include both comorbidity and anatomic considerations.
  • The presence of favorable access site anatomy is critical to success of both TF-CAS and TCAR.
  • Severe arch atheroma precludes use of TF-CAS due to high stroke risk, whereas atherosclerotic disease of the common carotid artery precludes use of TCAR.

Thoracic Aorta

Disease process and diagnosis

Disease of the thoracic aorta includes both aneurysmal disease as well as aortic dissection. Unlike AAAs, which are usually caused by atherosclerotic disease, thoracic aortic aneurysms are more likely to be associated with intimal dissection secondary to shearing stress from uncontrolled hypertension, inflammation, trauma, and, in some circumstances, connective tissue disease. Patients with thoracic aortic disease may be asymptomatic and diagnosed incidentally, or they may present with distal ischemia or embolic symptoms, compressive symptoms, or even rupture.¹⁶ The imaging modality of choice for both thoracic dissection and aneurysm is CTA, which is diagnostic and provides critical information regarding the patient’s aortic anatomy for operative planning.¹⁷ For patients presenting with thoracic or thoracoabdominal aortic aneurysms, operative repair is generally recommended when the aneurysm diameter is greater than 5.5 cm.^18,19 For patients with acute type B (descending) aortic dissections, operative repair is indicated for dissections complicated by such things as rupture or symptoms of malperfusion.²⁰ For acute uncomplicated type B aortic dissections, early management should focus on aggressive heart rate and blood pressure control with beta blockade or calcium channel blockade before consideration for operative intervention.

A brief overview of surgical approaches

Open repair.

Open repair is technically the gold standard for repair of the thoracic aorta,²¹ although there is an increasing push toward the use of endovascular repair, given the high rates of early postoperative morbidity and mortality with open approaches. Open repair remains the first-line approach to thoracoabdominal aortic aneurysm repair, as complex endovascular devices are not currently commercially available. There are also data suggesting that the results with open repair are more durable, and patients have decreased rates of long-term mortality and return to the operating room for reinterventions that would be common after endovascular repair.²² A brief overview of the procedural steps for an open thoracic/thoracoabdominal aortic aneurysm repair is as follows:

• Single lung ventilation is initiated, and the thoracic cavity is entered via a left posterolateral thoracotomy incision.

• The aorta is exposed by dividing the inferior pulmonary ligament and retracting the lung anteriorly.

• After control of the aorta proximal and distal to the extent of repair is obtained, the surgeon must decide whether to use the “clamp-and-sew” technique, in which the aorta is clamped while the anastomosis is created without visceral blood flow distally, or whether they will put the patient on partial left heart or full cardiopulmonary bypass.¹⁷

• The proximal anastomosis is created first, followed by the distal anastomosis and any necessary renovisceral anastomoses.

Despite higher rates of 30-day postoperative mortality with open, compared to endovascular thoracic aortic repair, retrospective analyses cite overall perioperative mortality in patients undergoing open repair to be as low as 3% in high volume centers. If patients survive the perioperative period, the 1- and 5-year survival rate can be greater than 70%.²³ This high survival likely reflects a treatment bias in the patients being selected for open repair, as this approach is very high risk and physiologically stressful, with associated complication rates ranging between 30% and 50%.²³

Thoracic Endovascular Aortic Repair.

In the mid-2000s, the Gore TAG trial compared TEVAR to open repair of thoracic aortic aneurysms and found that patients undergoing TEVAR had lower rates of perioperative cardiopulmonary complications and 30-day post operative mortality (2.1% with TEVAR compared to 11.7% in the open repair group). However, both groups experienced similar rates of perioperative stroke and spinal cord ischemia.^24,25 Multiple subsequent studies have confirmed the perioperative benefits with TEVAR, although longer term studies show consistently better freedom from reintervention with open repair.²⁶ A brief summary of the steps involved in TEVAR are follows:

• Percutaneous femoral artery access is obtained.

• Wire cannulation of the ascending aorta is achieved with a stiff wire.

• For cases involving a dissection, access via the true lumen is ensured using intravascular ultrasound before the stent graft is introduced via large bore sheath.

• For chronic aortic dissections and degenerative aneurysms, the stent graft is deployed with the intent to cover the entire descending thoracic aorta from an area of healthy tissue to an area of healthy tissue.

• For acute type B dissections, the goal is to ensure stent graft coverage of the most proximal intimal defect of the dissection.^17,25 The remaining aorta can be supported with bare metal dissection stents to stabilize the remainder of the dissection flap without excessive aortic coverage that may raise the risk of spinal cord injury.

To date, there are no RCTs that have been published that compare outcomes following TEVAR and open thoracic aortic repair. However, nonrandomized controlled studies have shown that in patients with favorable anatomy to support endovascular repair, TEVAR is noninferior and in some circumstances superior to open repair.²⁷ Favorable anatomy includes a noncalcified access site of adequate diameter to accommodate the large sheath required to deploy the stent graft, as well as a nontortuous aorta, and a 2-cm landing zone both proximal and distal to the proposed stent location. This landing zone allows the graft to form a good seal to prevent endoleak and stent migration.²⁰

• Key clinical points

  • Open thoracic aortic repair remains the gold standard for management of chronic thoracoabdominal aortic disease due to the current lack of commercially available branched endovascular devices.
  • Open thoracic aortic repair is associated with higher risks of cardiopulmonary events and mortality in the perioperative period but has a lower risk of reintervention compared with TEVAR long-term.
  • Successful TEVAR requires a proximal and distal landing zone for the stent graft that is a minimum of 2 cm in length.
  • The presence of favorable access site anatomy is critical to the success of TEVAR.

Abdominal Aorta

Disease process and diagnosis

An AAA is described as a 50% increase in the diameter of the abdominal aorta when compared with its baseline measurement. It is caused, most often, by degeneration of the tunica media secondary to atherosclerosis.²⁸ Approximately 80% of AAAs occur distal to the takeoff of the renal arteries, and men are more frequently affected than women.²⁸ AAA rupture accounts for approximately 15,000 deaths annually in the United States.^2,28 Many patients found to have AAAs are asymptomatic and diagnosed secondary to incidental imaging findings. Current guidelines support AAA screening via duplex ultrasound for all men and women aged 65 to 75 years with a history of tobacco use, men 55 years or older with a family history of AAA, and women 65 years or older who have smoked or have a family history of AAA.²⁹ Abdominal duplex ultrasound can be used to serially monitor a patient with AAA who is undergoing nonoperative surveillance; however, it often will overestimate the diameter.²⁸ Criteria for consideration of AAA repair include diameter greater than 5.5 cm in men or greater than 5.0 cm in women, saccular aneurysm, and symptomatic aneurysms. In larger aneurysms nearing size criteria for repair, CTA is the imaging modality of choice for most surgeons, as it provides valuable insight into the extent of the aneurysm with relation to the iliac and renal vasculature, as well as other anatomic features that are important when considering repair.

A brief overview of surgical approaches

Open abdominal aortic aneurysm repair.

Although open repair of AAAs is less commonly performed since the advent of the EVAR, there remains a role for its practice in vascular surgery today. The procedure can be briefly described as follows:

• The aorta is exposed by one of two methods: transabdominal, in which the patient is laying supine, or extended left retroperitoneal, in which the patient is in the right lateral decubitus position.

• If using a transabdominal approach, a left medial visceral rotation or division of the lesser omentum and gastrohepatic ligament is required to adequately expose the aorta.

• The patient is systemically anticoagulated and control of the aorta proximal and distal to the aneurysm is obtained.

• The aneurysm is incised longitudinally, and the proximal and distal anastomoses are completed in an end-to-end fashion.

• The aneurysm sac is closed over the graft at the completion of repair to prevent occurrence of an aorta-duodenal fistula.²³

Multiple RCTs have been published comparing EVAR and standard open repair of AAA. The United Kingdom (UK) EVAR 1 trial found that EVAR was associated with significantly lower rates of perioperative mortality compared with open repair (1.8% compared with 4.3%), but that long-term overall and aneurysm-related mortality did not differ significantly between the two groups.³⁰ Similar results were published from the Open versus Endovascular Repair (OVER) trial, which found that, despite early mortality benefit with EVAR, 2-year mortality did not differ between groups.³¹ All of these studies have focused on infrarenal AAA. Patients with juxtarenal or pararenal AAA are more complicated and require fenestrated endograft technology for repair. In patients with these more complex aneurysms, open repair may be preferred over an endovascular approach based on surgeon experience and access to complex endovascular repair options. One major limitation of EVAR (with or without fenestration) is the need for late reinterventions to address endoleaks, which occurs in up to 20% of patients.³⁰

Endovascular aortic repair.

Over the past three decades, EVAR has become the main-stay of surgical management for AAAs; it is estimated that 70% to 80% of aneurysms are now repaired endovascularly.^2,28 EVAR involves the following operative steps:

• Access to the bilateral common femoral vessels is obtained percutaneously.

• A series of sheaths and wires are used to gain access to the abdominal aorta, and the main body of the graft is inserted to just the level of the renal vessels (for infrarenal repair) or with alignment of the fenestrations with the renovisceral segment (for complex repairs).

• The main body of the stent graft is deployed from proximal to distal.

• The contralateral limb of the stent graft is then cannulated, and an iliac limb extension is placed, followed by deployment (and possible extension) of the remaining ipsilateral iliac limb. The bilateral iliac artery limbs are landed to obtain seal in the distal aspect of the common iliac arteries, taking care to preserve flow to the hypogastric arteries.

• A completion angiogram is performed to assess for leaks and adequate flow through the graft before the bilateral femoral arteriotomies are closed.²

In addition to ensuring bilateral femoral/iliac artery anatomy is favorable for access without significant atherosclerotic occlusive disease or calcification, aortoiliac anatomy must also be evaluated with CTA in all patients planned for EVAR. Aortic stent grafts are equipped with a set of Instructions for Use (IFU) created by the manufacturer. These instructions are slightly different for each device and describe the anatomic variations of the aorta for which they are proved to function. These anatomic criteria generally include aortic neck length, angulation, and diameter and iliac diameter characteristics (Table 1). Aortic neck length and angle are the most important criteria used to determine anatomic EVAR eligibility. These devices are occasionally used off-IFU in the management of ruptured AAA; however, outcomes have been shown to be inferior to those patients who received on-IFU care.³²

Table 1.

Endovascular stent graft instructions for use (IFU) in repair of abdominal aortic aneurysms as determined by the manufacturer.

Device	Neck Length (mm)	Neck Diameter (mm)	Infrarenal Angle (°)	Suprarenal Angle (°)
Cook Zenith	15	18–32	60	45
Endologix AFX	15	18–32	60	N/A
Endologix Ovation	10	16–30	60	N/A
Endologix Ovationa	7	16–30	45	N/A
Gore Excluder	15	19–29	60	N/A
Medtronic Endurant	10a	19–32	60	N/A

^aEndologix Ovation has 2 separate criteria for neck length based on degree of infrarenal angulation.

Data from Zarkowsky DS et al. 2021.³²

The Dutch Randomized Endovascular Aneurysm Management (DREAM) trial was another RCT completed in Europe that compared EVAR and open aortic repair for management of AAA. The investigators found that EVAR was preferred due to lower perioperative morbidity and systemic complications.³³ The UK EVAR 2 trial was conducted as a follow-up to the EVAR 1 trial to determine if there is benefit for patients who were deemed too high risk to undergo open AAA repair to undergo EVAR. The results showed a decrease in the rates of aneurysm-related mortality with EVAR when compared with observation; however, there was no significant decrease in all-cause mortality.

• Key clinical points

  • EVAR is associated with better perioperative outcomes compared with open AAA repair, but long-term morality is similar.
  • The need for late reintervention is higher for EVAR compared with open repair. As such, patients require routine long-term imaging surveillance after EVAR that is not required after open repair. Aortic neck length and angle are the most important criteria used to determine anatomic EVAR eligibility.
  • The presence of a favorable access site is critical to the success of EVAR.
  • Open AAA repair should be considered in patients whose aortic anatomy that does not fit the IFU criteria set forth by stent graft manufacturers.
  • Patients at high risk for open AAA repair based on comorbidities should be considered for endovascular management.

Suprainguinal Peripheral Arterial Disease

Disease process and diagnosis

Peripheral arterial occlusive disease (PAOD) can be anatomically separated into suprainguinal and infrainguinal categories, in which suprainguinal disease primarily refers to occlusive disease of the infrarenal aorta and iliac arteries and infrainguinal disease refers to occlusive disease from the common femoral arteries distally. The most common cause of PAOD in the United States is atherosclerosis, so the risk factors for disease development and basis of medical management are directly related to this process. Tobacco use is the single most important risk factor contributing to disease development,^34,35 along with hyperlipidemia. Patients with aortoiliac occlusive disease can present with a range of symptoms ranging from no symptoms (asymptomatic, most common) to claudication to chronic limb-threatening ischemia.³⁵ The severity of these symptoms depends on the distribution and severity of the PAOD, as well as the activity level of the patient. Although aortoiliac occlusive disease can often be diagnosed following a thorough history and physical examination, obtaining an ankle-brachial index is the best initial test to confirm the presence of PAOD. This involves calculating the ratio between the patient’s highest brachial artery systolic pressure and their posterior tibial artery systolic pressure and a value of less than 0.9 is considered abnormal. The first-line management of asymptomatic PAOD and claudication is medical optimization (ie, antiplatelet therapy, statin therapy, smoking cessation, and supervised exercise therapy).³⁶ Lower extremity revascularization via either an open or endovascular approach is reserved for patients who have persistent lifestyle-limiting symptoms despite maximal medical therapy and for patients with chronic limb-threatening ischemia (ie, rest pain or tissue loss). Of those patients who require an intervention, preoperative imaging before intervention is common, particularly in patients suspected to have suprainguinal disease. Although conventional angiography is still considered the gold standard for diagnosis of PAOD, CTA is quickly becoming the most widely used modality for preoperative assessment and operative planning.³⁴

A brief overview of surgical approaches

Anatomic and extra-anatomic revascularization.

Although the use of endovascular techniques in the management of suprainguinal PAOD have increased drastically in recent years, open anatomic bypass remains the gold standard for treatment. Anatomic revascularization refers to the use of endarterectomy or bypass to restore in-line arterial flow of the normal anatomy (eg, aortobifemoral bypass). Extra-anatomic bypass refers to revascularization of distal arteries from a proximal source that differs from normal anatomic flow (eg, axillofemoral bypass). Extra-anatomic procedures are usually reserved for patients who are contraindicated for or would not otherwise tolerate an extensive open vascular procedure. Because it remains the gold standard for management of suprainguinal PAOD, the authors focus on aortobifemoral bypass for the purposes of this paper. A brief description of the procedure is as follows:

• After the patient is prepped and draped, the femoral arteries are exposed via cut-down, and proximal and distal control is obtained. Care must be taken to obtain control of both the superficial femoral artery and profunda femoris.

• Aortic exposure is then obtained via a midline laparotomy incision.

• Retroperitoneal tunnels are then constructed for the bypass graft limbs using blunt dissection, taking care to tunnel the limbs posterior to the ureters to prevent a late ilio-ureteral fistula.

• The patient is systemically anticoagulated and the aorta cross-clamped.

• The aortic anastomosis is completed before the grafts are tunneled through the previously made tracts toward the groin where the femoral anastomosis is performed.

• Once both anastomoses have been completed, distal revascularization of the lower extremities is ensured and the incisions closed.

An aortobifemoral bypass surgery has relatively low perioperative mortality risk, and studies have shown patency rates ranging between 80% and 95% at 5 years and 75% and 80% at 10 years.^34,37 However, the operation is time-consuming, and an aortic cross-clamp is required, so patients must have the appropriate physiologic reserve. For patients who may not tolerate a large open operation, an endovascular approach may be more appropriate as long as the anatomy is amenable to it. The Trans-Atlantic Inter-Society Consensus for the management of PAD (TASC II) has made recommendations regarding the management of aortoiliac lesions and femoropopliteal lesions. The aortoiliac lesions have been split into four types based on location and length of the segment, type A, B, C, and D (Appendix A). Per these guidelines, endovascular intervention is recommended for type A and B lesions, whereas open repair is recommended for the more complex type C and D lesions.³⁴

Iliac artery stenting.

As noted previously, over the last several decades, endovascular therapy has become commonplace in the management of both acute and chronic PAOD, and open surgery is often reserved for patients without anatomy that is amenable to percutaneous angioplasty and stenting. An iliac stenting procedure can be described as follows:

• Femoral arterial access is obtained using a micropuncture needle, and a sheath is introduced into the vessel and advanced to the level of the lesion.

• Once the lesion is identified, it is traversed, and a balloon-expandable stent is placed across it extending from healthy artery to healthy artery.

• The arterial access site is then controlled using a closure device or appropriate manual pressure.³⁴

Rates of iliac artery stent patency have been shown to be upward of 95% initially and approximately 75% at 5 years.³⁸ Unfortunately, despite excellent long-term patency results with isolated iliac disease, results are much less favorable when the aortic bifurcation is included in the diseased segment. Previously, surgeons had used two separate bare stents in the bilateral common iliac arteries that would meet at the bifurcation, referred to as “kissing stents.” This technique unfortunately proved to have low rates of long-term graft patency.³⁸ Following the conclusion of the COB-EST Trial, which showed that covered endovascular stent grafts were superior to bare metal stents,³⁹ covered endovascular reconstruction of the aortic bifurcation (CERAB) was introduced as an alternative endovascular procedure.

Studies have found primary patency rates following CERAB to be approximately 86% to 87.5% at 1 year^40,41 and greater than 83% at 5 years.⁴² In a study directly comparing CERAB with aortobifemoral bypass, both procedures were found to have 100% technical success without significant difference in length of surgery, patency of the graft at 12 months, or 30-day mortality. However, patients who underwent CERAB had shorter intensive care unit length of stay and fewer postoperative complications than those who underwent aortobifemoral bypass.⁴³ It should be noted that the use of commercially available iliac stent grafts for CERAB is currently off-label.

• Key clinical points

  • The decision to perform an open anatomic, open extra-anatomic, or endovascular revascularization largely depends on the patients’ risk factors for surgery as well as their anatomy and pattern of disease.
  • The TASC II classification and guidelines recommend endovascular repair for type A and B aortoiliac lesions and open repair for type C and D aortoiliac lesions (see Appendix A).
  • The presence of adequate bilateral femoral artery access sites is crucial to performing iliac artery stent placement or CERAB.
  • CERAB and aortobifemoral bypass have similar rates of graft patency and mortality in the short and mid-term, although CERAB is associated with fewer postoperative complications.

Infrainguinal Peripheral Arterial Disease

Disease process and diagnosis

Infrainguinal PAOD encompasses both femoropopliteal and tibioperoneal occlusive disease. Similar to suprainguinal PAOD, the most common cause of the disease process is atherosclerosis. However, there has been a notable increase in tibioperoneal disease over the past two decades, likely due to the increasing prevalence of risk factors such as diabetes. Patients with infrainguinal PAOD often present with lower extremity claudication or chronic limb-threatening ischemia (CLTI). CLTI can take the form of rest pain, ulceration, or gangrene. These patients should undergo a thorough history and physical examination, and ankle-brachial indices (ABIs) should be obtained. An ABI less than 0.4 is thought to coincide with CLI, although many patients with CLTI in the setting of diabetes will have noncompressible vessels leading to falsely elevated ABI values. In these patients, toe pressure may be more accurate, with less than 60 mm Hg corresponding to ischemia. Other diagnostic imaging that may useful is arterial duplex imaging or CTA.^44,45 As noted earlier, TASC II has also created classification criteria and guidelines for femoropopliteal disease based on location and length of the segment affected (Appendix B). Per these guidelines, endovascular intervention is recommended for type A, B, and C lesions, whereas open repair is recommended for the more complex type D lesions.³⁴

A brief overview of surgical approaches

Lower extremity bypass grafting.

For many years, open surgical therapy has been the gold-standard treatment of infrainguinal PAOD and, despite the widespread use and increasing effectiveness of endovascular techniques, is still commonly performed. Open lower extremity bypass grafting is the technique of choice for patients with extensive disease as defined by the TASC II criteria. A good bypass requires adequate inflow and outflow. Most often the inflow vessel of choice is the common femoral artery, but the surgeon may also use the external iliac artery, superficial femoral artery, or above-knee popliteal artery depending on the pattern of disease. The outflow vessel should be the least diseased, most proximal vessel with adequate inline flow to the foot. The conduit of choice is autologous vein, ideally great saphenous vein followed by small saphenous vein or an upper extremity vein. If a patient does not have available autologous vein, synthetic conduits (ie, polytetrafluoroethylene or Dacron) may be used, ideally with an adjunct procedure such as a distal vein patch for any target below the knee. Once the appropriate conduit is determined, the procedure may proceed as follows:

• The great saphenous vein is harvested to an adequate length (if applicable).

• Incisions are made over the inflow and outflow vessels of choice, and the arteries are isolated. A tunneling device is used to bluntly create a tunnel for the bypass either subcutaneously or in an anatomic configuration. Counter incisions are made as needed along the course of the tunnel.

• The patient is systemically anticoagulated and the proximal anastomosis performed.

• The conduit is oriented appropriately and passed through the tunnel to the distal target, where the distal anastomosis is completed.

• Distal reperfusion is ensured before the end of the case.

When saphenous vein grafts are used, open bypass grafts have a 70% to 75% patency at 5 years depending on the distal target, with an approximate 80% limb salvage rate.⁴⁴ The Bypass versus Angioplasty in Severe Ischemia of the Leg (BASIL) trial was a multicenter RCT conducted to evaluate the efficacy of treating with angioplasty versus bypass grafting first for patients with CLTI secondary to infrainguinal disease. The BASIL trial found that, for as long as 2 years following intervention, there was no significant difference in amputation-free survival between the two groups.⁴⁶ In follow-up to this trial, a by-treatment-received analysis was conducted and found that the rate of early technical failure of angioplasty was much higher than for bypass. In addition, they found that after 2 years following intervention, patients who underwent lower extremity bypass using an autologous vein conduit had improved amputation-free and overall survival compared with patients undergoing endovascular revascularization.⁴⁷ Based on these data, younger patients with greater than 2 years of life expectancy and available autogenous vein are recommended for bypass.³⁶ However, one of the major criticisms of the BASIL trial is that endovascular interventions were limited to plain balloon angioplasty, which is known to have inferior patency outcomes compared with other newer technologies. There are currently two similar RCTs ongoing to compare open lower extremity bypass with endovascular revascularization for lower extremity disease.

Percutaneous vascular intervention.

Endovascular interventions, otherwise known as percutaneous vascular interventions (PVIs), are increasingly commonplace in the United States and can be applied to patients with both lifestyle-limiting claudication and CLTI. PVI is minimally invasive, can be performed on an outpatient basis, and involves immediate symptomatic improvement with minimal recovery time. Interventions include plain or drug-coated balloon angioplasty, plain or drug-coated stenting, atherectomy, or a combination of all three. A brief overview of the steps for PVI is briefly described:

• After an access site is identified, a micropuncture needle is used to gain access to the femoral artery, usually on the contralateral side to the lesion.

• Wires and sheaths are used to access the infrarenal aorta and select the contralateral iliac artery in an “up-and-over” technique.

• The lesion is traversed, and an intervention (balloon angioplasty, atherectomy, stent placement) is performed.

• The access site vessel is closed, and manual pressure is held to obtain hemostasis.

Primary stenting, when compared with angioplasty alone, has been found to have greater rates of patency at 1 and 2 years postprocedure.⁴⁴ Drug-coated technology (either balloon or stenting) is associated with better patency than non–drug-coated interventions,^48,49 but there is some controversy around a possible increase in mortality and major amputation with drug-coated technologies.^50,51 There is currently no evidence to support the routine use of atherectomy in patients with PAOD, as patency outcomes are similar to that of angioplasty with significantly higher complication rates and cost burden.^52,53

• Key clinical points

  • The TASC II classification and guidelines recommend endovascular repair for type A to C and open repair for type D femoropopliteal lesions (see Appendix B).
  • Results from the BASIL trial suggest that patients with CLTI who have greater than 2 years life expectancy and available autologous vein may have better outcomes with lower extremity bypass compared to an endovascular balloon angioplasty. There are a number of newer endovascular technologies that have not been evaluated compared with open lower extremity bypass, although RCTs are currently under way.
  • Percutaneous vascular interventions are minimally invasive with short recovery times, although long-term patency is better with open bypass.

SUMMARY

The practice of vascular surgery in the 21st century is always changing and ever expanding. The advancement of endovascular capabilities has made minimally invasive repair of even the largest of arteries possible with durable outcomes and fewer complications compared with traditional open surgery. It is of the utmost importance that clinicians recognize the pros and cons of both open and endovascular management of vascular disease in the context of important patient-centered factors and that they are able to apply them to their practice in order to provide optimal outcomes. In general, endovascular interventions are less physiologically stressful and have shorter recovery times with fewer perioperative complications compared with open surgery, but long-term outcomes tend to be relatively similar across approaches. For most disease processes, patient risk status and disease anatomy are the primary factors in determining whether an open or endovascular approach to surgery is warranted.

KEY POINTS.

• There has been a significant shift toward the use of endovascular therapy for the management of vascular disease over the past 30 years; however, open surgery remains a critical part of the vascular surgeon’s armamentarium.

• Brief overview of the surgical and endovascular approaches for management of carotid occlusive disease, thoracic aortic dissection and aneurysm, abdominal aortic aneurysm, and suprainguinal and infrainguinal peripheral arterial disease.

• Patient-centered perioperative considerations when considering open versus endovascular therapy for the aforementioned disease processes.

CLINICS CARE POINTS.

• The decision regarding open versus endovascular intervention in vascular surgery depends on many factors, including patient comorbidities, disease location and anatomy, vascular access, and the overarching goal of treatment.

• For carotid revascularization, carotid endarterectomy is the gold standard, but transfemoral or transcarotid artery stenting are endovascular alternatives currently indicated for use in high-risk patients with appropriate anatomy.

• For thoracic and abdominal aortic aneurysm repair, endovascular therapy has better short-term outcomes but more long-term reinterventions.

• When treating suprainguinal or infrainguinal peripheral artery disease, the decision to proceed with open surgery or endovascular therapy depends largely on the severity of disease being treated, in addition to underlying patient risk factors.

• In general, endovascular interventions have shorter recovery times and fewer perioperative complications but are associated with reduced longevity compared with open surgery.

APPENDIX A: THE TRANS-ATLANTIC INTER-SOCIETY CONSENSUS FOR THE MANAGEMENT OF PAD (TASC II) CLASSIFICATION FOR AORTOILIAC OCCLUSIVE DISEASE

Type A

• Unilateral (UL) or bilateral (BL) stenosis of the common iliac artery (CIA)

• UL or BL single short segment stenosis of external iliac artery (EIA) (≤3 cm)

Type B

• Short segment stenosis of the infrarenal aorta (≤3 cm)

• UL CIA occlusion

• Single or multiple stenoses totaling 3 to 10 cm involving the EIA without extension into the common femoral artery (CFA)

• Unilateral EIA occlusion

Type C

• BL CIA occlusion

• BL EIA stenoses totaling 3 to 10 cm long without extension into CFA

• UL EIA stenosis extending into CFA

• UL EIA occlusion involving origin of internal iliac artery (IIA) and/or CFA

• Heavily calcified UL EIA occlusion

Type D

• Infrarenal aortoiliac occlusion

• Diffuse disease involving the aorta and BL iliac arteries

• Multiple stenoses involving the UL CIA, EIA, and/or CFA

• UL occlusions of both CIA and EIA

• BL occlusions of EIA

APPENDIX B: THE TRANS-ATLANTIC INTER-SOCIETY CONSENSUS FOR THE MANAGEMENT OF PAD (TASC II) CLASSIFICATION FOR FEMOROPOPLITEAL OCCLUSIVE DISEASE

Type A

• Single stenosis ≤10 cm in length

• Single occlusion ≤5 cm in length

Type B

• Multiple stenoses or occlusions, each ≤5 cm in length

• Single stenosis or occlusion ≤15 cm in length and not involving the infrageniculate popliteal artery

• Single or multiple stenoses in the absence of continuous tibial vessel flow

• Single popliteal stenosis

Type C

• Multiple stenoses or occlusions totaling greater than 15 cm with or without heavy calcification

• Recurrent stenoses or occlusions that need treatment after 2 endovascular interventions

Type D

• Chronic total occlusions of the common femoral artery (CFA) or superficial femoral artery (SFA)

• Chronic total occlusion of the popliteal artery and proximal trifurcation