incidence of remedial procedures approximately 10%/yr.145,234 Many of the same complications that can

occur after open repair can occur after endovascular repair. However, the relative incidence of the

various complications is significantly different, and several complications inherent to EVAR have been

identified.

A variety of potential complications may arise during insertion of the delivery catheter or introducer

sheath. Indeed, access problems secondary to iliac stenosis and/or tortuosity are the most common

procedure-related complication. The outer diameters of the delivery sheaths are device-dependent, but

can range up to 25 Fr. Device companies are diligently working to decrease the profile of their

endografts, but the outer diameter of some endografts continues to be a limitation in some patients. The

cross-sectional outer diameter of a sheath corresponds to a diameter of 1/π mm (e.g., 24 Fr = 24/3.14

mm or 7.6 mm). A variety of techniques are available to correct or overcome small or diseased access

vessels, and these should be factored into the preoperative plan. Excessive force during insertion of

these large sheaths or delivery catheters can result in serious injury and perforation/disruption of the

vessels. Predictably, this can lead to significant hemorrhage and hemodynamic changes. The diagnosis

can be confirmed by arteriography and the bleeding controlled intraluminally using the device sheath or

a balloon catheter. A variety of endovascular salvage techniques are possible in this setting including

deployment of either the main device or a covered stent over the disrupted artery. Most major arterial

disruptions can be managed with endovascular techniques, but in the event they are unsuccessful, a

retroperitoneal incision with direct control of the iliac arteries can be performed expeditiously.

Safe conduct of an EVAR is predicated by sufficient knowledge of the various salvage techniques, the

necessary catheter and guidewire skills to execute these techniques and a complement of ancillary

equipment. However, the adage that “prevention is better than the cure” holds true and endovascular

surgeons should maintain a low threshold for constructing a retroperitoneal iliac conduit

prophylactically. Further, dissection within the arterial wall of the iliac vessels or aorta may also result

from misdirection or excessive force during cannulation of the vessels. When nonflow limiting, no

intervention may be necessary, but if flow limitation is noted, the dissection can usually be corrected by

cannulating the “true” lumen and reestablishing its integrity by deploying a peripheral (uncovered)

stent. If the wire is left in place until Doppler signal is confirmed in the feet, true lumen access is

maintained, making this much easier.

Graft deployment can be associated with mechanical problems related to the delivery system or

inappropriate positioning. A host of mechanical problems have been described, and the list will likely

expand with widespread application of the devices and the introduction of updated systems. Many of

the mechanical problems are device-specific and related to the actual sequence of events and

manipulations required. Troubleshooting guidelines and specific recommendations are available from

the manufacturers. Deployment of the endovascular graft below the proximal target site on the

infrarenal aorta may be corrected using an aortic extension cuff. Attempting to reposition the graft

further proximally after deployment has not been successful and is not recommended. Deployment of

the endovascular graft across the orifices of the renal arteries can potentially be corrected by displacing

the graft caudally. A guidewire can be passed over the flow divider and out the contralateral groin. The

entire graft can then be retracted caudally by pulling on the wires. Alternatively, a large balloon can be

inflated above the flow divider and retracted. Extreme care must be exercised during these maneuvers

to prevent complete dislodgement of the proximal main body from the neck. Deployment of the graft

across part of the renal orifice can be corrected by placing a stent within the lumen of the renal artery

and, thereby, displacing part of the main body caudally. This may be done from the femoral access or

may require arm access if more extensive unintentional coverage of the branch vessel has occurred.

Deployment of the endograft across the lumen of one internal iliac artery is usually tolerated provided

the contralateral vessel is patent and relatively free of occlusive disease. Indeed, it is relatively common

to embolize a single internal iliac artery in patients with common iliac artery aneurysms to facilitate

fixation of the graft limb in the external iliac artery. With coverage of a single hypogastric artery,

severe complications are rare, but buttock claudication and impotence are not.129 Occlusion of both

internal iliac arteries or occlusion of one vessel in the presence of contralateral disease may render the

pelvis ischemic. In the event of unintentional hypogastric artery coverage, the iliac limb can be pushed

cephalad using a sheath and its dilator. It should be emphasized that many of these remedial procedures

are not manufacturer approved and should only be attempted by experienced endovascular surgeons.

Due to the advanced age of many of these patients and their attendant comorbidities, open surgical

conversion should be contemplated only as a last resort after the endovascular options have been

exhausted, again emphasizing the need for advanced endovascular skills.

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It is relatively common to see an endoleak on the completion arteriogram. Treatment is contingent

upon the specific type of leak and their associated natural history although the majority of these early

endoleaks ultimately resolve.235 Type 1a/b (a-proximal, b-distal attachment site) and type 3 (fabric tear

or modular component separation/leak) endoleaks are particularly concerning and every reasonable

attempt to correct these defects should be made. The aneurysm sac is often exposed to systemic pressure

in the presence of a type 1 or type 3 endoleak, and, therefore, the rupture risk likely approaches that

associated with the untreated aneurysm. Both the type 1 and 3 endoleaks can potentially be corrected

by repeat balloon angioplasty at the proximal/distal attachment sites or at the modular interface. If

these measures are not successful, additional extension devices can be deployed. With the exception of

large proximal type 1 endoleaks, it is reasonable to manage most perioperative endoleaks expectantly

since many seal spontaneously after reversal of the anticoagulation or within the first 6 months. Indeed,

even type 1a endoleaks often thrombose before the first postoperative imaging study, although patient

selection, aneurysm diameter, and risk of rupture should be carefully considered before leaving an

endoleak of this nature. Thus, the surgeon should be mindful that the inability to obtain a satisfactory

exclusion of the aneurysm at the time of endograft implantation does not mandate a surgical conversion

at the same setting. In situations where there is concern for a persistent endoleak, an earlier

postoperative CT than the usual 1-month study may be advisable.

In the event that a significant endoleak persists on postoperative imaging, the potential options

include referral to another center with more expertise and branched/fenestrated capabilities, open

surgical repair with removal of any or all implanted devices, or no further treatment if the patient is a

poor surgical risk. Type 2 endoleaks (retrograde branch vessel related) have a relatively benign natural

history and do not merit aggressive intervention unless the aneurysm continues to increase in size over

time. Type 4 (trans-graft) endoleaks are self-limiting, and do not merit treatment at all. They are

identified as a diffuse contrast “blush” at the time of the completion arteriography. They represent a

diagnosis of exclusion and mandate that the more worrisome type 1 endoleak be excluded.

The spectrum of immediate postoperative complications after EVAR is comparable to that outlined for

after open repair and will not be repeated. However, the incidence of major, systemic complications

after EVAR is quite small. It is noteworthy that the incidence of both paraplegia and bowel ischemia are

comparable after endovascular and open repair although the mechanisms are different and likely due to

atheroembolism.210,236,237 Indeed, diffuse embolization to the small bowel has been reported after

endovascular repair and is almost uniformly fatal.236

The long-term complications after EVAR include endoleak, structural failure, need for remedial

procedures, need for open conversion, and rupture. These ongoing risks further emphasize the

importance of conscientious lifelong surveillance. All type 1 and 3 endoleaks identified during

surveillance merit further evaluation and correction given their ongoing rupture risk. Device migration

has been reported to cause type 1 endoleaks and has been associated with neck length, site of

deployment below the renal arteries, and surgeon/center experience.222 The treatment of these late

occurring type 1 and 3 leaks is identical to that for those occurring earlier and includes identification of

the specific site and remediation with either balloon angioplasty or an additional endovascular device,

although the latter is most common. Type 2 endoleaks merit intervention and treatment if the aneurysm

continues to increase in diameter, although the clinical scenario is an important deciding factor in these

cases. Identification of the type 2 endoleak can be challenging and may require selective catheterization

of the superior mesenteric or internal iliac arteries.238 A variety of approaches have been described to

treat the type 2 endoleaks including coil embolization, laparoscopic ligation of the feeder vessels, and

direct translumbar or transcaval injection of the aneurysm sac with glue or other thrombotic

agents.239,240

Aneurysms that continue to increase in size after EVAR merit further intervention and may require

open conversion due to their ongoing rupture risk. Continued aneurysm growth has been associated

with the type of prosthesis and baseline size in addition to the presence of endoleak.147 It should be

emphasized that the goal of aneurysm repair is to prevent rupture/death from rupture and that

endoleak and even sac enlargement are surrogate markers of potential late failure of the therapy.

Indeed, even the clinical significance of an enlarging sac in the absence of a visible endoleak is

controversial as long as a secure proximal and distal fixation of the endograft has been demonstrated.

To confound the issue further, rupture of aneurysms without an endoleak or a change in sac diameter

has also been reported, leading some to describe the phenomenon teleologically as endotension. A

presumed endoleak that is not detected on a properly performed contrast CT scan is typically not

identified on a catheter-based arteriogram. The proper diagnostic investigation of an endoleak should

2748

include interrogation of all the fixation sites and modular interfaces and selective injections of

mesenteric and hypogastric arteries with sufficient contrast dose and proper acquisition techniques. It

should be emphasized that open conversion and explant of the endovascular graft can be technically

more challenging than a de novo open repair and usually requires suprarenal or supraceliac aortic

control. In the absence of infection, it is not always possible (or necessary) to remove the entire device,

particularly when the device has suprarenal fixation. It is possible to transect the endovascular graft

near the usual site of the infrarenal aortic anastomosis and incorporate the fabric/stents of the graft into

the anastomosis. Temporary distal vascular control can be achieved by clamping the limbs of the

endovascular graft. The limbs of a bifurcated surgical graft may be anastomosed directly to the

endograft limbs if they are securely attached to the iliac artery. In properly chosen elective patients,

open conversion can be performed with similar outcomes to primary open juxtarenal AAA repair.241

A variety of device-specific complications, including strut fracture, fabric tears, and buckling of the

graft, have been identified, and the list will likely increase with the introduction of newer technologies.

Importantly, these may present at any time throughout the postoperative period. An extensive

discussion of all the potential device-related complications and their treatment is beyond the scope of

this chapter. Importantly, regression of the aneurysm, although typically desirable, has been associated

with significant conformational changes in the endografts and has resulted in limb thrombosis and

disruption of the distal attachment sites.242 These adverse outcomes in the presence of decrease in the

aneurysm size have been termed the “paradox of success.”

REPAIR OF RUPTURED ABDOMINAL AORTIC ANEURYSMS

Open Repair

The approach to the patient with a ruptured AAA is similar to the elective scenario with the exception of

several points that merit further comment. In order to achieve a reasonable result, the diagnosis should

be made in an expeditious fashion and the appropriate treatment initiated quickly. The endovascular

approach appears to be associated with a lower mortality rate, but this remains to be further

documented given the inherent bias in terms of patient selection and publication.85,86,88–90

The patient should be taken emergently to the operating room once the diagnosis of a ruptured

aneurysm has been made. Unnecessary delays to complete the preoperative evaluation should be

avoided. Unfortunately, the diagnosis is not always made in a setting where an operating room and the

appropriate resources are immediately available. In this scenario, the patient should be transferred to

the appropriate setting as quickly as possible, which may require transfer to a facility able to provide a

higher level of care. When the decision is made to transfer a patient with a ruptured aneurysm, the

transferring physician should keep several principles in mind, with the most important being avoidance

of hypertension and the concept of permissive hypotension.243

When bringing the patient to the operating room, the OR team and anesthesia personnel should be

notified immediately upon diagnosis and instructed that the patient is en route. The necessary

instrument trays should be opened, the room temperature in the operating room increased, adjunctive

measures to maintain body temperature obtained, and the intraoperative autologous salvage device

prepared. Notably, hypothermia has been shown to be a strong, independent predictor of mortality after

ruptured aneurysm repair.244 The blood bank should be notified and instructed to send 6 units of blood

to the operating room. This should be type O negative or type-specific if cross-matched units are not

available. Furthermore, the blood bank should be instructed to expedite the cross-match of additional

red blood cells, fresh frozen plasma, and platelets.

On arrival at the operating room, the patient should be prepared and draped before intubation and

the induction of anesthesia, which includes draping from chin to knees or toes, depending on the

surgeon’s preference. This allows access to both groins for endovascular proximal control, and the chest

in the event that resuscitative thoracotomy is required. During the patient preop, the surgeon and

assistants should gown/glove and be prepared to make the incision at the time of induction, because

patients with ruptured aneurysms frequently become hypotensive after the induction of anesthesia.

A midline incision should be made and supraceliac aortic control obtained. The aorta/esophagus can

be difficult to identify, especially in a hypotensive patient during a deluge of blood from the abdomen.

A nasogastric tube placement quickly after induction makes identifying the gastroesophageal junction

much easier, and thus the proper location of the supraceliac clamp. The esophagus should be manually

moved to the patient’s left and the gastrohepatic ligament, the crus of the diaphragm, and the

2749

connective tissue enveloping the aorta can be divided using blunt finger dissection. If necessary, control

of the aorta can be achieved manually by either occluding the aorta between the fingers and thumb or

compressing it against the vertebral bodies. Definitive control should be obtained with an aortic clamp.

Of course, care should be utilized during these maneuvers to prevent injury to the esophagus or the

aorta itself.

Aortic control can also be achieved through a variety of other means: thoracotomy with occlusion of

the descending thoracic aorta, intraluminal control of the infrarenal aorta with a compliant balloon

placed through a femoral artery, or supraceliac control via a retroperitoneal incision, if that approach

was chosen. The aortic surgeon should be familiar with these various techniques because they can be

helpful in certain clinical settings, but the midline approach with supraceliac control is recommended

for most ruptured infrarenal aneurysms. After supraceliac aortic control has been obtained, the infrarenal

aorta is dissected and vascular control is achieved below the level of the renal arteries. The hematoma

from the ruptured aneurysm often facilitates the dissection by displacing the normal tissue planes.

However, the normal tissues may be obscured, and care should be taken not to injure the venous

structures, particularly the left renal vein, which can lead to much more blood loss. The supraceliac

aortic clamp can be released after infrarenal control has been obtained, and flow can be restored to the

visceral vessels. It is imperative that these various steps are coordinated with the anesthesia team, and

it is recommended that the supraceliac clamp be left in position to facilitate reapplication if necessary.

Distal vascular control can be achieved with either vascular clamps or intraluminal balloons, depending

on the character of the iliac vessels.

Patients can be heparinized after proximal and distal vascular control has been obtained, provided

that the patient is doing well and the case is proceeding expeditiously.245 However, the decision to

anticoagulate the patient is contingent on a variety of factors, including the quantity of blood lost,

presence of coagulopathic bleeding, body temperature, and hemodynamic status. Anticoagulation

potentially reduces thrombotic complications, but it exacerbates coagulopathic bleeding. Before

completion of the distal anastomoses, thromboembolectomy catheters should be passed distally through

the iliac vessels to remove any thrombus or debris. It is recommended that the inferior mesenteric

artery be implanted (if patent) to reduce the risk of postoperative colonic ischemia. The heparin effect

can be reversed with protamine after confirmation of distal lower-extremity arterial signals. The

administration of plasma, platelets, or both should be considered at this point if any evidence of

coagulopathic bleeding is noted. A thromboelastogram (TEG) can be very helpful in determining the

need for supplemental blood products.246

The postoperative course after repair of a ruptured aneurysm is predictably more complicated and

protracted than after elective repair.247–251 Both the intensive care unit and total hospital length of stay

are significantly increased. The mortality and complication rates are likewise significantly increased. As

noted above, the mortality rate for patients with ruptured AAAs who make it to the operating room is

approximately 50%.13 The spectrum of postoperative complications after repair of a ruptured aneurysm

is essentially the same as after elective repair although the incidences are increased. The incidence of

bowel ischemia may be as high as 40% and routine colonoscopy may be indicated.211 Abdominal

compartment syndrome252,253 and adrenal insufficiency254 have been reported after ruptured aneurysm

repair and merit consideration in patients that are not doing well. Notably, adrenal insufficiency was

identified in almost 70% of patients with unexplained postoperative hypotension after ruptured

aneurysm repair.254 Predictably, long-term survival is decreased relative to patients undergoing elective

repair225 although the overall quality of life is comparable.255

ENDOVASCULAR REPAIR FOR RUPTURE

EVAR has the potential to greatly impact the operative mortality rate for ruptured AAAs, but depends

heavily on aortic anatomy, more so than for open repair. Although the worldwide experience is

relatively small, early outcomes are impressive, particularly given the significant mortality/morbidity

associated with the open repair which has remained relatively constant over the past few decades.83

Despite the appeal of the endovascular approach, its application requires a defined protocol/approach

consisting of an experienced endovascular surgeon, a committed team, an available operating room with

the necessary imaging equipment, and an inventory of suitable devices. Several recent studies have

estimated that approximately 20% to 50% of patients with ruptured aneurysms are anatomically

suitable for endovascular repair using conventional devices although this number may increase with the

introduction of newer devices and/or the extension beyond the manufacturers’ IFU.256–258

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The endovascular approach for the treatment of ruptured AAAs can be briefly summarized and has

been described by multiple authors.259,260 Patients with a presumed diagnosis of a ruptured AAA that

are hemodynamically stable, as defined by a systolic blood pressure >80 mm Hg and normal

mentation, should undergo a rapid CT arteriogram to determine their anatomic suitability. Notably,

aggressive fluid resuscitation should be avoided during this period to avoid the risk of releasing the

retroperitoneal tamponade. The anatomic criteria for EVAR include an acceptable neck anatomy (length

≥10 mm, diameter ≤32 mm, freedom from prohibitive angulation [device specific]) and adequate

access vessels (≥7 mm diameter). The operative plan is generated and the appropriate devices selected

based upon the CT findings and patients are taken directly to the operating room from the scanner.

Oversizing of the aortic neck ≥20% and encroachment on the orifices of the renal arteries with

adjunctive stenting are both tolerated in an attempt to limit the necessary inventory and increase the

proximal fixation zone, respectively. Access to the common femoral arteries is obtained using a

percutaneous approach with direct exposure and repair delayed until the completion of the procedure.

In the absence of severe hypotension, the remaining conduct of the procedure is essentially the same as

described in the elective setting. It is not usually necessary to occlude the aorta with an intraluminal

balloon although one should be readily available in the event that the patients become

hemodynamically unstable.261,262 The criteria for an acceptable result are somewhat less in the

emergent setting and persistent attempts to achieve a perfect radiographic result should be avoided. The

ultimate goal is to prevent further hemorrhage and to allow the patient to be resuscitated, which does

require the absence of a type I or III endoleak, but otherwise does not require an absolutely perfect

radiographic result. Further interventions including conversion to open repair may be necessary at a

later date, but these can usually be performed in an elective fashion.

Notably, patients treated with EVAR are at risk of developing abdominal compartment syndrome,

which can be related to intra/retroperitoneal hemorrhage and/or aggressive volume resuscitation. The

surgeon should consider prophylactic celiotomy or retroperitoneal evacuation with placement of an

open abdominal dressing at the conclusion of the procedure, which may be required in up to 20% of

patients.263,264

ADDITIONAL CONSIDERATIONS

Isolated Iliac Artery Aneurysms

Isolated iliac artery aneurysms are rare and have been reported to occur with an incidence ranging from

0.03% in autopsy series

11 to 2.2% in single-institution series.265 The common iliac artery is involved in

approximately 70% of the cases, and the internal iliac artery in the remainder.266 Aneurysmal

involvement of the external iliac artery, either in combination with the common iliac artery or alone, is

distinctly rare. These isolated iliac artery aneurysms should be differentiated from the common iliac

artery aneurysms that occur concomitantly with AAAs. Simultaneous aneurysmal involvement of the

aorta and common iliac arteries occurs in about 10% to 20% of all AAAs

11,12; this pattern should be

considered as one disease process and treated accordingly.

The natural history of isolated iliac artery aneurysms is poorly defined because of their low incidence.

The clinical risk factors appear to be similar to those for AAAs with the highest incidence seen among

elderly men. Unlike patients with AAAs, a significant proportion of patients with isolated iliac artery

aneurysms present with symptoms.266 These symptoms may result from either rupture or compression

of adjacent structures including the bowel, ureters, iliac veins, and nerves. The clinical presentation of

patients with a ruptured iliac artery aneurysm is similar to that of ruptured AAAs, and the diagnosis

should be included in the differential for patients with genitourinary symptoms and normal findings on

urinalysis and testicular examination. CT arteriography is optimal for confirming the diagnosis of an

isolated iliac artery aneurysm. The utility of ultrasonography is limited by the posterior course of the

iliac vessels and the overlying bowel. Large iliac artery aneurysms may occasionally be palpated during

rectal or gynecologic examination, and ruptured iliac artery aneurysms may present with ecchymosis of

the perineum.

The principles of treatment for asymptomatic, isolated iliac artery aneurysms are similar to those for

AAAs, and operative repair is justified when the risk for rupture offsets the risk of repair. Unfortunately,

the natural history of isolated iliac artery aneurysms and the appropriate threshold for repair remain

unresolved. The reported growth rate for iliac artery aneurysms <3 cm is 0.11 cm/yr while that for

aneurysms 3 to 5 cm is 0.26 cm/yr.267 Although rupture has been reported for aneurysms smaller than 2

2751

cm, it is rare for aneurysms smaller than 3 cm to rupture.265,268 Operative repair is generally

recommended for good-risk patients with isolated iliac artery aneurysms ≥3.5 cm. The frequency of

surveillance imaging studies should be dictated by the size of the aneurysm with yearly studies

appropriate for aneurysms <3 cm with 6 month intervals appropriate for aneurysms between 3 and 3.5

cm.265

The treatment or repair of isolated iliac artery aneurysms depends on the specific vessel involved and

the extent of the aneurysm. Theoretically, common iliac artery aneurysms can be repaired with an

interposition graft or a covered stent provided that there is a sufficient proximal and/or distal neck to

sew the anastomosis or seat the graft. However, this is rarely an option because the aneurysm

involvement of the vessel usually extends over its whole length. Therefore, repair necessitates replacing

the whole common iliac artery with a bifurcated graft similar to the approach for patients with

combined aortic and iliac artery aneurysms. Both open and endovascular approaches are available and

the concerns about the individual choice (i.e., open vs. endovascular) are likely similar to that outlined

for AAAs. In addition, the principles of treatment for both the open and endovascular approach of

isolated iliac artery aneurysms are similar to AAAs. In the case of open repair, the proximal anastomosis

should be performed immediately below the renal arteries to prevent subsequent aneurysm

degeneration of the infrarenal cuff while the distal anastomosis should be performed at the common

iliac bifurcation on the involved side. The distal anastomosis on the uninvolved common iliac artery can

be performed to a nonaneurysmal segment. For the endovascular repair, the graft should be seated

immediately below the renal arteries and at the takeoff of the internal iliac artery on the side opposite

the aneurysm. The iliac limb on the side of the aneurysm is seated in the external iliac artery and

necessitates embolization, branched stent graft, or open surgical bypass of the ipsilateral internal iliac

artery.

The treatment of internal iliac artery aneurysms is typically exclusion. This can be performed using

either an endovascular or open approach although the former is likely preferred due to its simplicity.

Bypass of an internal iliac artery aneurysm is often not possible because there is rarely a proximal or

distal neck. Indeed, the aneurysmal involvement usually extends to the common iliac bifurcation and

the distal aspect usually arborizes into multiple smaller vessels. The principles of the endovascular

treatment include obliterating both the arterial inflow and the outflow of the aneurysm. The outflow is

usually occluded using selective coil embolization, although a variety of other agents, such as glues and

gelfoam, have been described. Placing a covered stent across the orifice of the internal iliac extending

from the common to the external iliac vessels eliminates the inflow. The open approach requires

vascular control of the distal common iliac and proximal external iliac arteries. The internal iliac artery

is then opened by incising the aneurysm, and the branches are oversewn from within. The proximal

internal iliac artery can be either oversewn at its takeoff, or the resultant defect at the common iliac

bifurcation can be repaired with patch angioplasty. The appropriate treatment for patients with bilateral

internal iliac artery aneurysms remains unclear. Exclusion of both vessels has the potential to cause

severe pelvic ischemia that may not be remediable. A conservative approach is likely justified in this

setting with a higher threshold for intervention appropriate for the second vessel. Treatment options

include excluding only the larger vessel, attempted revascularization, and staged exclusion after

sufficient time has elapsed to facilitate potential collateral development. Regardless of the treatment

option, it is important to assess the status of the pelvic circulation including the profunda femoral artery

and the inferior mesenteric artery, which are important collaterals to the pelvis.

INFLAMMATORY ABDOMINAL AORTIC ANEURYSMS

Approximately 5% of all AAAs are described or considered inflammatory.269 These are characterized by

a dense inflammatory response encasing the anterior and lateral walls of the infrarenal aorta with

sparing of the posterior aspect. The inflammatory response consists of a dense cellular infiltrate that has

a white, glistening appearance on inspection. The inflammation results in an increase in wall thickness

with the difference between the inner and outer diameters of the aorta ranging from 1 to 5 cm. The

cause of this inflammatory process remains unresolved, but it is likely an autoimmune phenomenon.

Indeed, some type of autoimmune disorder has been identified in up to 20% of patients with

inflammatory aneurysms.270

Patients with an inflammatory abdominal aneurysm are predominantly male and frequently present

with symptoms of back or abdominal pain. The triad of a pulsatile abdominal aortic mass, abdominal

pain, and an elevated erythrocyte sedimentation rate (ESR) has been described. Abdominal

2752