Introduction
Endovascular aneurysm repair (EVAR) is currently the most commonly performed procedure
to treat aortoiliac aneurysms, surpassing open repair a long time ago. Restricted
by certain anatomic factors of the aneurysm, EVAR technology is, however, continuously
evolving and expanding our armamentarium. Low-profile delivery systems, fenestrated
endografts, endoanchors, and endovascular aneurysm sealing methodologies,[1]
[2]
[3] among others, are often used in challenging anatomies. This is particularly crucial
for high-risk patients including those with respiratory, heart, or chronic kidney
disease (CKD). Herein, we present the case of a patient with bilateral common iliac
artery aneurysms (IAAs) associated with a short–infrarenal aorta that constituted
a contraindication to most conventional endografts. The patient was successfully managed
with the low-profile Altura endograft system, following embolization of the internal
iliac arteries.
Case Presentation
A 71-year-old man with end-stage renal disease on hemodialysis was referred to our
outpatient clinic with bilateral common IAAs, incidental findings during the workup
to rule out obstructive uropathy or a renal parenchymal disease as potential causes
of his CKD. He had known CKD for over a year, and 3 months earlier he started a regular
hemodialysis program at an outside facility, currently through a right internal jugular
vein catheter. Past medical history besides CKD included coronary artery disease with
percutaneous transluminal coronary angioplasty of one vessel, about 8 years ago, hypertension,
dyslipidemia, depression, and glaucoma. Orally taken medications included aspirin
100 mg QD, clopidogrel 75 mg QD, diltriazem 60 mg TID, carvedilol 3.125 mg BID, clonidine
150 mg (1–1/2–1), atorvastatin 20 mg QD, duloxetide 60 mg QD, and omeprazole 20 mg
QD. Additionally, he was on latanoprost eye drops QD. There were no known allergies.
Past surgical history included open cholecystectomy, 10 years ago, and more recently
excision of a basal cell skin carcinoma with part of the underlying mandible in his
left zygomatic region. He had never been a smoker. Family history was negative for
aortic or other aneurysms. On physical examination of the abdomen, a scar from a right
Kocher's incision, and also obesity was noted, with no palpable masses. A right internal
jugular vein hemodialysis catheter was noted. There was mild peripheral edema in his
legs, and femoral and dorsalis pedis pulses were normal. We did not palpate popliteal
artery aneurysms. A scar in his left zygomatic region was noted. No carotid bruits
were auscultated. The remaining examination was unremarkable.
On computerized tomographic (CT) angiography ([Fig. 1]), common IAAs were noted, with diameters measuring 6.1 cm on the right side and
3.1 cm on the left side. The infrarenal aorta showed also a small 3.2-cm aneurysm.
Aortic length from the lowest left renal to its bifurcation was only 6.7 cm. The infrarenal
neck was straight, with a diameter of 19.6 mm below the lowest renal, 27 mm in length,
and an infrarenal angle of 16.2 degrees. Diameter of external iliac arteries was at
least 7.8 mm. Celiac artery and superior and inferior mesenteric arteries were patent
with no stenotic lesions being detected.
Fig. 1 Three-dimensional reconstruction computed tomography image (arterial phase) of the
abdominal aorta and the iliac arteries. The presence of bilateral iliac artery aneurysms
and a short infrarenal portion of the aorta can be noted. LAO, left anterior oblique.
Preoperative workup was performed to identify an endovascular solution for this apparently
high-risk patient with coronary artery and chronic kidney disease. Conventional endografts
were not suitable because of the short length of the infrarenal aorta, as described
above, which was shorter than the shortest commercially available main body of all
but one endograft available on the market.
An Altura endograft (Altura Endograft System, Lombard Medical, Didcot, Oxfordshire,
United Kingdom), which is polyester with a nitinol frame featuring active suprarenal
fixation and double D-shaped proximal stents) was suitable. However, there was no adequate landing zone
in the common iliac arteries bilaterally. As part of the preoperative preparation,
staged preoperative IAA embolization was decided. Staging was opted to reduce the
possibility of pelvic floor and sigmoid colon ischemia, likely to be possible based
on patient's past medical history and a patent inferior mesenteric artery, respectively.
Initially, embolization of the left IAA with a 16-mm Amplatzer-II vascular plug (St.
Jude Medical, MN) delivered with a crossover technique from the contralateral side,
through a standard 6-Fr vascular sheath, was performed on an outpatient basis. Vessel
occlusion was confirmed after a few minutes angiographically. Approximately a month
later, our patient was admitted and underwent embolization of the right IAA with a
16-mm Amplatzer-II vascular plug (St. Jude Medical, MN) using the same technique,
without any complication. Vessel occlusion was confirmed after a few minutes on completion
angiography.
The next day, the Altura Endograft System, with its bilateral iliac components, was
deployed, landing at the level of the external iliac arteries, with technical details
as described below.
Through standard longitudinal groin incisions, the common femoral artery was identified,
dissected and controlled with vessel loops, bilaterally. Introducer sheaths were exchanged
for the delivery systems of the two aortic components of the stent graft (diameter,
24 mm; length, 90 cm; Altura Endograft System, Lombard Medical), one for each side,
which were advanced to the level of the infrarenal aorta in a crossed limb configuration.
We proceeded with the proper alignment of the stent grafts by rotating the delivery
system so that three radiopaque tantalum markers on both stent grafts aligned with
each other, allowing the flat faces of the two D-shaped stent grafts (unique for the aortic components) to be aligned in a medial
position ([Fig. 2A]), to ensure proper positioning of this modular endograft and prevent endoleak. After
the alignment, we rotated the handle on one of the delivery systems to unsheathe the
proximal end of the stent graft, so that we could perform an angiography through the
delivery system, and this way we identified the renal arteries, with the left one
being the lowest one. The single lateral marker of each aortic component was used
to position them just below the renal arteries ([Fig. 2B]). We then rotated the handle on both devices to expose the proximal end of both
stent grafts, with further adjustments being made to properly orientate the grafts.
We then proceeded with the compression maneuver of the proximal end of the stent grafts,
using the mechanism on the delivery system, to form the D-shape on the proximal end. Because one of the devices was not properly aligned, the
mechanism used to form the D-shape was reversed allowing accurate repositioning and adjustment of the alignment
of the stent-graft.
Fig. 2 (A) Intraoperative X-ray using the C-arm demonstrating the aortic components of the
Altura stent graft appropriately positioned so that the three markers (star with lines)
of each component are aligned medially opposite each other and the renal markers (arrows)
are aligned laterally. (B) Intraoperative aortogram showing proper alignment of the aortic components, but
somewhat cephalad compared with the renals, not allowing deployment before caudal
movement. (C) Kissing balloon technique with two 32 mm CODA (COOK MEDICAL) molding balloon catheters
dilating the proximal parts of the aortic components of the stent grafts.
Subsequently, we proceeded with releasing the proximal bare stent, on both devices,
which has the fixation barbs, and then finished deploying the aortic components. Since
this graft does not require cannulation, we proceeded with placement of the device
for right iliac component (diameter, 13 mm and length, 65 cm, Altura Endograft System,
Lombard Medical) and then a similar left iliac device over Lunderquist wires (COOK
MEDICAL, Bloomington, IN). These stent-grafts deploy from the distal end to the proximal
end allowing for proper placement at the common iliac bifurcation, although on this
occasion, the distal landing zones were the external iliac arteries, bilaterally.
The delivery systems of the two stent grafts were replaced with two 16-Fr 30-cm introducer
sheaths (COOK MEDICAL). Two 32-mm CODA (COOK MEDICAL) molding balloon catheters were
used to dilate the stent grafts, particularly at the neck using the kissing balloon
technique ([Fig. 2C]) and their joint areas.
A completion aortogram through an 8-Fr 45-cm introducer sheath (Cordis) placed through
the right common femoral showed proper placement of all stent-graft components and
no endoleaks ([Fig. 3]), although a possible bulging was visualized in the right aortic component, corresponding
to the left iliac limb due to crossed limb configuration (arrowhead, [Fig. 3A]). Fluroscopy time was 28 minutes and contrast material totaled 140 mL. Peripheral
pulses were present at the conclusion of the procedure. The postoperative course was
uneventful, without any complications.
Fig. 3 Completion aortogram showing proper placement of all stent graft components (aortic
components in A, indicated by an arrow, and iliac limbs in B and C) with no endoleak. However, a possible bulging was visualized in the right aortic
component, corresponding to the left iliac limb due to crossed limb configuration
(arrowhead, A).
The patient was discharged home on the second postoperative day.
Repeat imaging with CT angiography, 45 days later, ruled out endoleak or endograft
migration; however, billowing of one of the aortic components mimicking an endoleak
was evident ([Fig. 4]) at the point bulging was seen intraoperatively ([Fig. 3A]). Aneurysm sacs were slightly reduced to 5.8 and 2.9 cm for the right and left IAAs,
respectively. On further imaging with color-coded duplex ultrasonography on the sixth
postoperative month, there was no endoleak detected, and aneurysm sacs were further
reduced to 5.3 and 2.7 cm for the right and left IAAs, respectively. Our patient is
closely followed-up with repeat imaging planned for the 12th postoperative month.
Fig. 4(A) Computed tomography angiography of the abdominal aorta at 45 days after the procedure.
Maximum intensity projection (MIP) coronal reconstruction shows excellent patency
of the aortic graft. (B and C) Axial images of the aorta at the level of L3 vertebrae. On the arterial phase (B), the white arrow indicates protrusion of the contrast contour of the right aortic
component and on the venous phase (C) contrast protrusion has the same appearance with arterial phase (white arrow). (D) This is indicative of billowing of the right aortic component, which continues as
the left iliac component and is further evident (arrow) in the three-dimensional MIP
reconstruction.
Discussion
We present the case of a 71-year-old man with end-stage renal disease on hemodialysis
with bilateral common IAAs and a short–infrarenal aorta that precluded use of most
conventional endografts. These anatomic issues were successfully managed with a two-piece
D-shaped Altura endograft for the aorta with bilateral iliac components landing at
the level of the external iliac arteries.
A short–infrarenal aorta presents a special challenge for most endograft types because
their main body is made by the various manufacturers to be longer than the aorta;
this cut-off point varies among the various endograft types. Actually, it is the length
between the proximal part of the body and the contralateral gate that restricts its
use in infrarenal aortic segments of a certain length, so that the contralateral gate
opens inside the aorta and not the ipsilateral iliac artery, thus preventing cannulation
from the contralateral side and inline placement of the contralateral limb.
In our case, the AFX endovascular AAA system (Endologix, Irvine, CA) would have been
an alternative solution, because its main body is made as short as 40 mm in length.
Similarly, the Nellix Endovascular Aneurysm Sealing System (EVAS; Endologix) could
have been used, although currently available only within clinical trials. Placement
of an endograft with bilateral limbs, such as in our case obviated use of an aortouniiliac
endograft, contralateral iliac occlusion and femorofemoral bypass grafting, known
to be associated with a higher risk of infection than totally endovascular solutions.
Our patient was at a high risk for open repair mainly because of his history of end-stage
renal disease requiring hemodialysis. Even EVAR in this patient population carries
substantial risks, with mortality figures up to 5.2% in one recent study.[4] Given that this risk is not prohibitive for EVAR, we proceeded after bilateral hypogastric
embolization. Still the later procedure in combination with cessation of flow to the
inferior mesenteric artery following EVAR may be associated with pelvic and sigmoid
colon ischemia, particularly in this morbid patient population. However, such complications
were not observed in our case and were thought to occur less often than a fatal outcome
following open repair or expectant management.
We successfully implanted an Altura endograft with no evidence of complications on
CT angiography a month and a half later. Published experience with this endograft
type is excellent.[5]
[6] In a single series on 89 patients, endografts were successfully implanted in 99%.[5] Despite a 4.5% reintervention rate during the first 30 days, on midterm follow-up
(median, 12.5 months; range, 11.5–50.9), there were no aneurysm ruptures, surgical
conversions, or AAA-related deaths. Clinical success was reported to be 94% (84/89)
at 30 days, 98% (85/87) at 6 months, and 99% (82/83) at 1 year. The authors concluded
that properly selected AAA patients can be safely treated using the Altura Endograft
System with favorable midterm outcome.
No endoleak or endograft migration on CT angiography was seen in our case at 45-day
follow-up, indicating excellent technical and clinical success. Billowing mimicking
an endoleak was, however, evident on imaging. This represents aneurysmal degeneration
of the outer fabric material manifesting as a bulging sac of contained contrast due
to weakening of the fabric material between the metal struts, which are not attached
to the fabric material except at the two ends. Although contrast material is manifest
beyond the skeleton, it is still contained within the graft. Although billowing is
considered a benign finding,[7] recent reports have cast some doubt.[8]
[9] Billowing has been reported only for the Powerlink endograft so far,[7]
[8]
[9]
[10] and we believe that this is the first reported case of billowing in a patient with
the Altura endograft. The lack of long-term data on this graft (median, 12.5 months)
should be viewed as a limitation to its use. We will closely monitor our patient.
