Branched Stent-Grafts for Endovascular Repair of Aortic and Iliac Aneurysms

Natural History of the Iliac Arteries after Endovascular Abdominal Aortic Aneurysm Repair and Suitability of Ectatic Iliac Arteries as a Distal Sealing Zone

Purpose:

To investigate the natural history of dilated common iliac arteries (CIA) exposed to pulsatile blood flow after endovascular abdominal aortic aneurysm repair (EVAR) and the suitability of ectatic iliac arteries as sealing zones using flared iliac limbs.

Methods:

Follow-up computed tomograms of 102 CIAs in 60 EVAR patients were investigated. Diameter changes in CIAs ≤16 mm (group 1) were compared with changes in vessels where a dilated segment >16 mm in diameter continued to be exposed to pulsatile blood flow (group 2). Within group 2, cases in which the stent terminated proximal to the dilated artery segment (2a) were compared with those that had been treated with a flared limb (2b).

Results:

The mean CIA diameter increased by 1.0±1.0 mm in group 1 (p<0.001 versus immediately after EVAR) and by 1.5±1.7 mm in group 2 (p<0.001 versus immediately after EVAR) within an average follow-up of 43.6±18.0 months. Diameter increase was more pronounced in dilated CIAs (p=0.048), and it was not significantly different between groups 2a and 2b (p=0.188). No late distal type I endoleak or stent-graft migration associated with CIA ectasia was observed.

Conclusion:

Dilatation of the CIA is significant after EVAR, and it is more pronounced in ectatic iliac arteries. Although ectatic iliac arteries appear to be suitable sealing zones in the short term, continued follow-up is mandatory.

Strategy for Isolated Iliac Artery Aneurysms

We retrospectively reviewed 41 patients with isolated iliac artery aneurysms presenting over a 21-year period. The mean age was 72 years. Mean aneurysmal diameter was 6.0 cm (range, 3.2–13 cm). The aneurysms were located in the common iliac artery in 31 patients, internal iliac artery in 7, and both arteries in 3. Rupture occurred in 20 patients (49%). The frequency of rupture of isolated iliac artery aneurysms was significantly higher than that of abdominal aortic aneurysms (8%) during the same period. The 30-day mortality was 9.8%; death in all 4 patients was due to rupture of the aneurysm. The surgical procedure was aneurysmectomy and replacement with a bifurcated prosthetic graft in 24 patients (59%), closure of the common iliac artery with a femorofemoral crossover in 7, minilaparotomy in 3, thromboexclusion in 6, and endoluminal stent-graft repair in one. In contrast to abdominal aortic aneurysms, isolated iliac artery aneurysms can be treated by various methods other than replacement with a bifurcated prosthetic graft. When selecting a strategy for such aneurysms, it is important to choose an approach appropriate to the location and risk, because of the frequency of rupture.

Fenestrated stent grafts for the treatment of complex aortic aneurysm disease: A mature treatment paradigm

The introduction of fenestrated stent grafts (SGs) to treat abdominal aortic aneurysms (AAAs) with short proximal necks began in 1999. Nowadays, the whole visceral aorta can be treated totally by endovascular means. The established use of fenestrated devices to treat complex AAAs as a first-line management option has been previously reported. An up-to-date evaluation of the literature was performed including all types of publications regarding the use of fenestrated technology to repair complex AAAs. Fenestrated repair is now an established alternative to hybrid/chimney/snorkel repairs. However, specific criteria and prerequisites are required for the use and improvement of this method. Multiple device morphologies have been used incorporating the visceral arteries in various combinations. This modular strategy connects different devices (bridging covered stents and bifurcated SGs) with the aortic main body, thus excluding the aneurysm from the circulation. Precise deployment of the fenestrated SG is mandatory for successful visceral vessel revascularization. Accurate SG sizing and customization, a high level of technical skill, and facilities with modern imaging techniques including 3D road mapping and dedicated hybrid rooms are required. Most experience has been with the custom-made Zenith Cook platform, although off-the-shelf devices have been recently implanted. More complex repairs have been performed over the last few years, but device complexity has also increased. Perioperative, mid-term, and a few recently reported long-term results are encouraging. Secondary interventions remain the main problem, similar to that observed after traditional endovascular abdominal aortic aneurysm repair (EVAR).

Successful endovascular exclusion of a common iliac artery aneurysm: off-label use of a reversed Cook Zenith extension limb stent-graft

Open iliac aneurysm repair has been historically associated with major morbidity and mortality. The introduction of endovascular devices and techniques has expanded the armamentarium available to treat these aneurysms, and several methods have been reported. However, the off-label use of a commercially available, flared extension limb stent-graft to treat a common iliac artery aneurysm (CIA) by preliminary extracorporeal predeployment, endograft reversal, and reinsertion into the delivery sheath to fashion a tapered endograft has not been previously reported. A case report of a CIA aneurysm diagnosed 9 years after transperitoneal tube graft abdominal aortic aneurysm repair treated with ipsilateral hypogastric artery occlusion with an Amplatzer plug and placement of a reversed, tapered extension limb stent-graft is herein presented.

A novel hybrid approach to the treatment of common iliac aneurysms: antegrade endovascular hypogastric stent grafting and femorofemoral bypass grafting

A progressively enlarging left common iliac artery aneurysm developed in a 72-year-old man 7 years after open abdominal aortic aneurysm repair with a bifurcated Dacron graft. Because both the right hypogastric and inferior mesenteric arteries had been ligated at the initial operation, preservation of left hypogastric flow was critical to avoid pelvic or intestinal ischemia. He was a poor open surgical candidate owing to obesity, a hostile abdomen, and multiple medical comorbidities. Therefore, a novel hybrid approach was used consisting of left transbrachial selective left hypogastric artery catheterization, followed by deployment of two, overlapping, antegrade, covered stent grafts extending from the proximal left graft limb into the left hypogastric artery. A right-to-left femorofemoral crossover bypass was added to perfuse the left lower extremity and was performed in end-to-end fashion to the left common femoral artery to exclude and prevent retrograde flow into the iliac aneurysm. Also presented are potential procedural pitfalls and a detailed review of open, endovascular and hybrid options to preserve hypogastric flow when treating iliac aneurysms in complex, high-risk patients.

The Aortic Arch and Ascending Aorta: Are They Within the Endovascular Realm?

Aneurysms involving the ascending aorta and arch have been historically treated with open surgical techniques requiring cardiopulmonary bypass and, in cases involving the aortic arch, utilizing deep hypothermic circulatory arrest. The reported rates of mortality range from 0% to 16.5% for surgery addressing ascending aorta and arch pathology, and stroke rates of 2% to 18%. These statistics highlight the invasiveness of these procedures. Continued development and evolution of endovascular stent-grafts has allowed for the application of endovascular interventions in the proximal descending thoracic aorta and visceral aortic segments. Based on early experiences, attention has been focused on the ascending aorta and aortic arch, where unique challenges exist and have been addressed by both extra-anatomic bypass and novel methods incorporating branched and fenestrated devices. Device evolution, coupled with increased experience by the aortic interventionalist, has resulted in successful cases of endovascular management of every section of the aorta, including aortic valve replacement. However, these experiences have also been accompanied by significant complications. In this light, new endovascular endeavors must be considered in the context of conventional treatment options, hybrid procedures, and novel branched devices. Patient factors, such as specific anatomic issues, comorbid diseases, and functional levels must play an important role in the determination of therapeutic options. Ultimately, a clinician who understands the disease and is familiar with all treatment options (interventional, medical, and open surgical) will be best suited to provide care for the aortic patient. Finally, as with any assessment of interventional strategies, rigorous follow-up and serial imaging are essential.