**Abstract**

Although endovascular aortic aneurysm repair (EVAR) has become an attractive, minimally invasive option for patients with abdominal aortic aneurysms (AAA), significant challenges in arterial access exist in patients with concomitant aortoiliac occlusive disease (AIOD), particularly for more advanced TASC C and D lesions. Under these circumstances, endograft delivery is possible but requires extensive preoperative planning and intraoperative techniques including but not limited to surgical conduit creation, plain balloon angioplasty, endoconduit placement, and subintimal recanalization. Newer generation aortic endografts have also shown promise in accommodating compromised access vessels. Concomitant AIOD and compromised access vessels complicate EVAR and increase operative time and complexity. Therefore, extreme caution, meticulous preoperative planning, familiarity and facility with the various surgical and endovascular options needed to circumvent these obstacles are essential for safe and effective delivery of EVAR in this high-risk subset of patients. The purpose of this chapter is to present standard approaches for access in patients undergoing EVAR; discuss how advanced AIOD precludes routine access; and present various methods to overcome difficult access in patients undergoing EVAR.

**Keywords:** abdominal aortic aneurysm, endovascular aortic aneurysm repair, aortoiliac occlusive disease, endograft, aorta, iliac artery, femoral artery, access, endoconduit

#### **1. Introduction**

Endovascular aortic aneurysm repair (EVAR) has expanded to more than 75% of elective abdominal aortic aneurysm (AAA) repairs due to its lower perioperative complication and high technical success rate [1, 2]. Despite its advantages, however, there are specific limitations that preclude EVAR delivery, making open AAA repair a more suitable option for select patients. In general, patient age and overall health are important considerations in deciding between EVAR versus open repair. Anatomic factors may also limit use of EVAR in select patients, and one of the single most important of these is proximal neck anatomy [3]. Unsuitable, hostile proximal neck features include angulation of ≥60°, neck length ≤ 10 mm, focal bulge in the neck >3 mm, and thrombus involving ≥50% of the aortic diameter—all common EVAR limiting factors [4]. In addition, access related issues due to atherosclerotic occlusive disease remain major barriers to EVAR as up to 36% of patients with AAA

suffer from some degree of aortoiliac occlusive disease (AIOD) [5]. Concomitant AIOD may preclude EVAR in 6–15.4% of patients [6, 7]. The current Trans-Atlantic Inter-Society Consensus (TASC) guidelines consider an aneurysm in combination with a significant iliac artery stenosis or occlusion a TASC D lesion, and open surgical repair is suggested for these patients [8]. However, open repair is still associated with an in-hospital mortality rate of approximately 4%, particularly in this highrisk subset of patients with significant comorbidities that are associated with their peripheral arterial disease [9]. This combination of factors makes patients with AAA and AIOD even higher-risk candidates for open surgery.

Within the subset of patients with AAA and concomitant AIOD, about 15% require adjunctive access-related procedures to facilitate EVAR [10]. Furthermore, previously stented iliofemoral vessels are increasingly encountered and pose significant technical challenges for endovascular access and EVAR limb durability [11]. Overall, access-related complications—such as dissection and rupture—at the time of EVAR approach 10% compared to 15% in patients with concomitant AIOD [12]. Even though there has been a general reduction in device size in recent years compared with older generation aortic endoprostheses, some of the commonly used devices and most branched and fenestrated repair endovascular systems continue to require larger-diameter sheaths and delivery conduits. There are currently no clinical guidelines delineating the optimal therapy in patients with AAA and concomitant AIOD. Thus, familiarity with various techniques that can overcome compromised access vessels is essential for the modern-day vascular surgeon. These techniques have been developed to circumvent previously prohibitive anatomy and are discussed in this chapter. The emphasis herein will be on less invasive endovascular means of facilitating access in patients with compromised aortoiliac anatomy in the setting of AAA.

#### **2. Access**

#### **2.1 Surgical access**

The common femoral artery (CFA) is the most commonly accessed site for EVAR and has traditionally been approached via surgical cutdown. Typically, an incision is made parallel to and approximately two-finger breadths inferior to the inguinal ligament at the midway point between the anterior superior iliac spine and the pubic symphysis overlying the femoral pulse if palpable [13]. The superficial femoral fascia (contiguous with Scarpa's fascia) is divided obliquely, while the deep femoral fascia is divided parallel to femoral artery.

In cases of severely diseased or occluded CFAs, focal endarterectomy with patch angioplasty may be necessary prior to or immediately after EVAR to avoid limbthreatening ischemia and to facilitate EVAR delivery. Longitudinal skin incisions extending inferiorly from the inguinal ligament distally to the femoral bifurcation are preferred under these circumstances to facilitate adequate endarterectomy with profundaplasty if necessary. The proximal superficial femoral artery (SFA)—if patent and relatively disease-free—might be another option for access in cases of compromised CFAs or hostile groins. In such cases, the SFA is accessed via direct surgical cutdown along the medial border of the sartorius muscle [14].

#### **2.2 Percutaneous access**

Percutaneous access for EVAR was initially described in 1999, when the Prostar XL device (Abbot Vascular, Abbott Park, IL) was used for suture-mediated closure

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*Endovascular Aortic Aneurysm Repair in Patients with Aortoiliac Occlusive Disease*

access is maintained throughout the serial deployment process.

of femoral arteries [15]. The device is indicated for closure of vessels after percutaneous access of up to 10 Fr. If required, multiple devices can be used for larger

The more popular Perclose ProGlide device (Abbot Vascular, Abbott Park, IL) is indicated for femoral access closure of up to 8 Fr for each closure device. It differs from the Prostar XL device in that it uses a single monofilament polypropylene suture instead of two braided polyester sutures. Multiple Perclose devices can be used to achieve closure for larger caliber arteriotomies up to 24 Fr inner diameter. This is achieved by deploying Perclose devices 45° clockwise and counterclockwise relative to the initially deployed device at the 12 o'clock position [17]. If needed, additional Perclose devices can be deployed for adequate hemostasis as long as wire

A recent meta-analysis of outcomes of percutaneous EVAR showed a technical success rate (defined as freedom from additional perioperative procedures) of 93%. There was an increased risk of conversion to cutdown when using sheaths ≥20 Fr [18]. Notably, both severe or anterior common femoral calcification and small access vessel diameter (<5 mm) have been associated with failed percutaneous access [18, 19]. In our own experience, we have found extreme iliac vessel tortuosity to be another predictor of unsuccessful percutaneous EVAR, given difficulty in closure device tracking and proper deployment of the footplate. To date, there has been no appropriately powered prospective, randomized study comparing percutaneous suture-mediated closure devices to open cutdown in EVAR. For now, a higher threshold for a total percutaneous approach and a readily available conversion mechanism to open surgical cutdown is advisable, particularly if one or more anatomically limiting factors are present.

In order to prevent inadvertent arterial injury and to avoid emergent measures,

Choice of conduit for EVAR delivery in the setting of AIOD is based on individual anatomy and disease severity. In general, TASC A and B disease may be amenable to simple balloon angioplasty of stenotic iliac arteries, after which the aortic endograft and/or required delivery sheath can be advanced. We caution against repeat balloon angioplasty and the use of oversized balloons due to associated life-threatening rupture that may result. In situations where simple angioplasty

evaluation of the caliber and disease burden of all access vessels should be performed preoperatively based on adequate contrast-enhanced imaging. While computed tomography angiography (CTA) remains the preoperative imaging modality of choice, compromised access vessels may require catheter-directed angiography for pre-operative evaluation and/or treatment of access-related disease in anticipation of EVAR and for more appropriate device selection. The latter should be, in part, based on access vessel considerations such as patency, diameter, tortuosity, and severity of calcification. This is particularly important in older patients who have calcified, minimally elastic vessels and cannot tolerate excessive oversizing or stretching of the access vessels [20]. The minimum access vessel diameter requirement varies considerably based on the EVAR device manufacturer and the instructions for use (IFUs) for each particular device. A list of some of the commonly used endografts and their required iliac artery diameter has been provided in **Table 1**.

*DOI: http://dx.doi.org/10.5772/intechopen.83848*

caliber access closure [16].

**3. Challenging access**

**3.2 Conduit selection**

**3.1 Predicting access difficulty**

*Endovascular Aortic Aneurysm Repair in Patients with Aortoiliac Occlusive Disease DOI: http://dx.doi.org/10.5772/intechopen.83848*

of femoral arteries [15]. The device is indicated for closure of vessels after percutaneous access of up to 10 Fr. If required, multiple devices can be used for larger caliber access closure [16].

The more popular Perclose ProGlide device (Abbot Vascular, Abbott Park, IL) is indicated for femoral access closure of up to 8 Fr for each closure device. It differs from the Prostar XL device in that it uses a single monofilament polypropylene suture instead of two braided polyester sutures. Multiple Perclose devices can be used to achieve closure for larger caliber arteriotomies up to 24 Fr inner diameter. This is achieved by deploying Perclose devices 45° clockwise and counterclockwise relative to the initially deployed device at the 12 o'clock position [17]. If needed, additional Perclose devices can be deployed for adequate hemostasis as long as wire access is maintained throughout the serial deployment process.

A recent meta-analysis of outcomes of percutaneous EVAR showed a technical success rate (defined as freedom from additional perioperative procedures) of 93%. There was an increased risk of conversion to cutdown when using sheaths ≥20 Fr [18]. Notably, both severe or anterior common femoral calcification and small access vessel diameter (<5 mm) have been associated with failed percutaneous access [18, 19]. In our own experience, we have found extreme iliac vessel tortuosity to be another predictor of unsuccessful percutaneous EVAR, given difficulty in closure device tracking and proper deployment of the footplate. To date, there has been no appropriately powered prospective, randomized study comparing percutaneous suture-mediated closure devices to open cutdown in EVAR. For now, a higher threshold for a total percutaneous approach and a readily available conversion mechanism to open surgical cutdown is advisable, particularly if one or more anatomically limiting factors are present.

### **3. Challenging access**

*Vascular Access Surgery - Tips and Tricks*

the setting of AAA.

**2.1 Surgical access**

**2.2 Percutaneous access**

**2. Access**

suffer from some degree of aortoiliac occlusive disease (AIOD) [5]. Concomitant AIOD may preclude EVAR in 6–15.4% of patients [6, 7]. The current Trans-Atlantic Inter-Society Consensus (TASC) guidelines consider an aneurysm in combination with a significant iliac artery stenosis or occlusion a TASC D lesion, and open surgical repair is suggested for these patients [8]. However, open repair is still associated with an in-hospital mortality rate of approximately 4%, particularly in this highrisk subset of patients with significant comorbidities that are associated with their peripheral arterial disease [9]. This combination of factors makes patients with

Within the subset of patients with AAA and concomitant AIOD, about 15% require adjunctive access-related procedures to facilitate EVAR [10]. Furthermore, previously stented iliofemoral vessels are increasingly encountered and pose significant technical challenges for endovascular access and EVAR limb durability [11]. Overall, access-related complications—such as dissection and rupture—at the time of EVAR approach 10% compared to 15% in patients with concomitant AIOD [12]. Even though there has been a general reduction in device size in recent years compared with older generation aortic endoprostheses, some of the commonly used devices and most branched and fenestrated repair endovascular systems continue to require larger-diameter sheaths and delivery conduits. There are currently no clinical guidelines delineating the optimal therapy in patients with AAA and concomitant AIOD. Thus, familiarity with various techniques that can overcome compromised access vessels is essential for the modern-day vascular surgeon. These techniques have been developed to circumvent previously prohibitive anatomy and are discussed in this chapter. The emphasis herein will be on less invasive endovascular means of facilitating access in patients with compromised aortoiliac anatomy in

The common femoral artery (CFA) is the most commonly accessed site for EVAR and has traditionally been approached via surgical cutdown. Typically, an incision is made parallel to and approximately two-finger breadths inferior to the inguinal ligament at the midway point between the anterior superior iliac spine and the pubic symphysis overlying the femoral pulse if palpable [13]. The superficial femoral fascia (contiguous with Scarpa's fascia) is divided obliquely, while the deep

In cases of severely diseased or occluded CFAs, focal endarterectomy with patch angioplasty may be necessary prior to or immediately after EVAR to avoid limbthreatening ischemia and to facilitate EVAR delivery. Longitudinal skin incisions extending inferiorly from the inguinal ligament distally to the femoral bifurcation are preferred under these circumstances to facilitate adequate endarterectomy with profundaplasty if necessary. The proximal superficial femoral artery (SFA)—if patent and relatively disease-free—might be another option for access in cases of compromised CFAs or hostile groins. In such cases, the SFA is accessed via direct

Percutaneous access for EVAR was initially described in 1999, when the Prostar XL device (Abbot Vascular, Abbott Park, IL) was used for suture-mediated closure

surgical cutdown along the medial border of the sartorius muscle [14].

femoral fascia is divided parallel to femoral artery.

AAA and AIOD even higher-risk candidates for open surgery.

**62**

#### **3.1 Predicting access difficulty**

In order to prevent inadvertent arterial injury and to avoid emergent measures, evaluation of the caliber and disease burden of all access vessels should be performed preoperatively based on adequate contrast-enhanced imaging. While computed tomography angiography (CTA) remains the preoperative imaging modality of choice, compromised access vessels may require catheter-directed angiography for pre-operative evaluation and/or treatment of access-related disease in anticipation of EVAR and for more appropriate device selection. The latter should be, in part, based on access vessel considerations such as patency, diameter, tortuosity, and severity of calcification. This is particularly important in older patients who have calcified, minimally elastic vessels and cannot tolerate excessive oversizing or stretching of the access vessels [20]. The minimum access vessel diameter requirement varies considerably based on the EVAR device manufacturer and the instructions for use (IFUs) for each particular device. A list of some of the commonly used endografts and their required iliac artery diameter has been provided in **Table 1**.

#### **3.2 Conduit selection**

Choice of conduit for EVAR delivery in the setting of AIOD is based on individual anatomy and disease severity. In general, TASC A and B disease may be amenable to simple balloon angioplasty of stenotic iliac arteries, after which the aortic endograft and/or required delivery sheath can be advanced. We caution against repeat balloon angioplasty and the use of oversized balloons due to associated life-threatening rupture that may result. In situations where simple angioplasty


#### **Table 1.**

*List of current abdominal and thoracic aortic endografts and their size specifications. \*Represents outer diameter (OD) measurement (not sheath size) for Medtronic devices.*

does not seem to accommodate EVAR delivery, we recommend prophylactic covered stent placement prior to more aggressive angioplasty and the disruption of native vessel plaque. This technique provides a control mechanism if rupture occurs during angioplasty. For angioplasty alone, balloon diameter should not exceed the native vessel adventitia-to-adventitia diameter. Meticulous maintenance of guide wire access as well as immediately available balloon occlusion catheters and appropriately sized covered stents are strongly recommended at the time of angioplasty.

More advanced TASC C & D lesions often require a more comprehensive planning for safe and effective EVAR delivery. While open aortic surgery remains

**65**

*Endovascular Aortic Aneurysm Repair in Patients with Aortoiliac Occlusive Disease*

a consideration in these patients, high risk candidates warrant consideration for

Open surgical conduits provide the advantage of larger conduits for device delivery and surgically exposed access for repair of any inadvertent arterial injury. Most surgical conduits are created at the distal common or proximal external iliac artery (EIA) using a lower retroperitoneal incision. The ideal strategy depends on the status of the iliac arteries (e.g., calcification and patency of internal iliac arteries) and the surgical risk for each individual patient. Most patients can tolerate a retroperitoneal exposure. However, this is a less ideal option in patients with hostile anatomy, prior surgery or radiation, retroperitoneal fibrosis, or in those with extensive comorbidities [20]. Standard surgical precautions should be taken to avoid ureteral injury and sympathetic plexus injury on the left side in men. Despite their advantages, however, surgical conduits should be used judiciously, given their reported association with longer operative times, hernias, prosthetic remnant infec-

Although the common iliac artery (CIA) can be directly accessed with a sheath, a conduit often simplifies the procedure and provides increased availability of the iliac landing zone for EVAR. In creating the conduit, first the iliac arteries are controlled, and then a longitudinal arteriotomy is made anteriorly extending from the distal common to the external iliac artery [20]. A 10-mm Dacron graft is spatulated and anastomosed end-to-side to the native vessel. Of note, Fogarty occlusion balloon is a useful adjunct for vessel control in cases where severe calcification of the

A stab incision can be performed in the lower abdominal wall to exteriorize the conduit [23]. If there is severe external iliac occlusive disease, the conduit can be tunneled under the inguinal ligament to a counter incision in the groin to be converted to an iliofemoral bypass at the completion of the case [14]. This maneuver is also suitable for cases with planned repeat interventions in the future. Access is established via direct graft puncture after clamping and stabilizing the externalized distal end of the graft. Upon completion of the procedure, the conduit can be

In cases with anticipated prolonged lower extremity ischemia time and patients with severe aortoiliac and profunda femoral disease, a temporary femoral artery conduit can be used to minimize lower extremity ischemia—reperfusion. A 10-mm femoral conduit is anastomosed end-to-side to the CFA using a standard oblique or longitudinal groin incision. The conduit allows periodic withdrawal of occlusive

iliac arteries precludes safe and adequate surgical clamping [20].

ligated and oversewn near the anastomosis leaving a short stump.

graft after flow is restored to lower extremity [20].

sheaths with restoration of flow while maintaining guide-wire access [20].

In cases with planned staged interventions for extensive thoracoabdominal repairs, permanent iliofemoral conduits are better options to avoid redo retroperitoneal exposure. Depending on patient anatomy and the extent of iliofemoral disease, there are several possible configurations. Iliofemoral bypass can be created from the distal CIA or proximal EIA to the proximal CFA, with access established into the

Although direct iliac exposure might allow for better control of iliac injury, it is not without complications. In a study of 15,082 patients who underwent infrarenal EVAR from 2005 to 2012, 147 (1%) required iliac conduit or direct iliac access and had a higher rate of long-term mortality. [24] Compared to standard bilateral femoral exposure, surgical conduits also have a 1.8-fold increase in perioperative complications and a 1.5-day increase in length of hospital stay, but have no statistically significant difference in early mortality [25]. Furthermore, compared to

*DOI: http://dx.doi.org/10.5772/intechopen.83848*

tion, and prolonged recovery [22].

**3.3 Surgical conduits**

creative and less invasive endovascular approaches [21].

a consideration in these patients, high risk candidates warrant consideration for creative and less invasive endovascular approaches [21].
