Sequential coil embolization of bilateral internal iliac artery aneurysms prior to endovascular abdominal aortic aneurysm repair

Adjunctive Procedures for Challenging Endovascular Abdominal Aortic Repair: When Needed and How Effective?

Endovascular aneurysm repair (EVAR) is now considered the first choice treatment modality for abdominal aortic aneurysm (AAA) treatment. Advocates for endovascular strategies will try to treat all AAA by EVAR, regardless if the anatomy is conducive for treatment or not. However, the long-term outcomes of EVAR outside the instructions for use (IFU) due to a hostile aneurysmal neck or iliac artery anatomy are known to be poor. The EVAR procedures can be classified according to the technical difficulty, IFU, and need for visceral revascularization: standard, adjunctive, and complex EVAR. The situation required for adjunctive procedures can be classified as the following four steps: a hostile neck (i.e., short or severely angled); large inferior mesenteric or lumbar artery; tough iliac artery anatomy, such as a short common iliac artery and stenotic external iliac artery; and limitations in vascular access. This article will discuss the adjunctive procedures to overcome hostile aneurysm neck and unsuitable iliac artery anatomy.

Endovascular Repair as First-Choice Treatment for Anastomotic and True Iliac Aneurysms

Purpose:

To report our experience with the endovascular repair of iliac aneurysms secondary to aortoiliac bypass grafting.

Methods:

Thirteen patients (12 men; age range 62–86 years) with histories of aortoiliac reconstructions were treated with endovascular stent-grafts for 11 false and 2 true iliac aneurysms that averaged 5.2 cm in diameter (range 3.0–7.0). Via a percutaneous access and 9-F or 12-F sheaths, Passager or Wallgraft stent-grafts were delivered to exclude the aneurysms.

Results:

Twelve (92%) of 13 interventions were completed satisfactorily; 1 procedure for a true iliac aneurysm was converted to traditional bypass grafting. Two patients underwent additional surgical procedures. The average hospital stay for the patients with endovascular repairs only was 3 days (range 2–5). After a mean follow-up of 28 months (range 17–40), no complication or endoleak has been detected in any patient, and all endografts are patent.

Conclusions:

Endovascular repair is an effective treatment for secondary aneurysms arising after aortoiliac surgery. It is less invasive and involves a shorter hospital stay. Endovascular repair should be the first choice treatment for iliac aneurysms.

Internal iliac coverage during endovascular repair of abdominal aortic aneurysms is a safe option: A preliminary study

Endovascular aneurysm repairs lacking suitable common iliac artery landing zones occasionally require graft limb extension into the external iliac artery, covering the internal iliac artery origin. The purpose of this study was to assess incidence of type II endoleak following simple coverage of internal iliac artery without embolization during endovascular aneurysm repair. Three hundred eighty-nine endovascular aneurysm repairs performed by a single surgeon (2004-2015) were reviewed. Twenty-seven patients underwent simple internal iliac artery coverage. Type II endoleak was assessed from operative reports and follow-up computed tomography imaging. No patient suffered type II endoleak from a covered internal iliac artery in post-operative computed tomography scans. Follow-up ranged from 0.5 to 9 years. No severe pelvic ischemic complications were observed. In conclusion, for selected cases internal iliac artery coverage without embolization is a safe alternative to embolization in endovascular aneurysm repairs, where the graft must be extended into the external iliac artery.

Low-profile versus standard-profile multibranched thoracoabdominal aortic stent grafts

OBJECTIVE

This study compared midterm results using low-profile stent grafts (LPSGs; 18F) and standard-profile stent grafts (SPSGs; 22F-24F) for endovascular pararenal and thoracoabdominal aortic aneurysm (TAAA) repair.

METHODS

From July 2005 to March 2015, 134 asymptomatic patients underwent endovascular repair of a pararenal or TAAA using multibranched aortic stent grafts. In March 2011, we started using a LPSG with nitinol stents and thin-walled polyester fabric. Prospectively collected data on operative repair, complications, and outcomes were compared between the two groups.

RESULTS

LPSGs were used in 37 patients (8 women [21.6%]; mean ± standard deviation age, 72.5 ± 8 years) and SPSGs in 97 patients (25 [26%] women; mean age, 73 ± 8 years). Medical comorbidities, aneurysm size, and aneurysm extent were similar in the LPSG and SPSG groups. Mean follow-up time was longer in the SPSG group (3.1 ± 2 years) than in the LPSG group (1.3 ± 0.9 years; P < .001). Operative time, renal failure, stroke, myocardial infarction, and perioperative death were not significantly different between the two groups (P > .05). Aneurysm-related death, rupture, stent graft migration, type I or III endoleaks, aneurysm enlargement >5 mm, branch vessel occlusion, and reintervention rates were similar between the two groups (P > .05). However, the combined outcome of conduit use or access artery injury occurred at a lower rate in the LPSG group than in the SPSG group (16% vs 36%; P = .03). Women experienced significantly higher rates of conduit use and access artery injury than men after repair with SPSGs (64% vs 26%, respectively; P = .001) but similar rates after repair with the LPSG (25% vs 14%, respectively; P = .45).

CONCLUSIONS

LPSGs had similar safety profile and midterm outcomes compared with the SPSGs for treatment of pararenal and TAAA. The substitution of LPSGs for SPSGs lowered the number of patients who required conduit insertion to avoid access artery injury, especially in women, thereby reducing an otherwise striking gender difference.

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.

Evaluation of a Novel Endoluminal Vascular Occlusion Device in a Porcine Model: Early and Late Follow-up

PURPOSE

To evaluate the efficacy of a new vascular occlusion device (VOD) in a preclinical controlled study versus embolization coils.

METHODS

The Biomerix VOD was made from a biodurable porous polyurethane matrix in the shape of a cylinder measuring 1.5 cm long by 6.0 mm wide. Thirty-three swine were selected to undergo embolization of a 3 to 5-mm-diameter iliac artery using either a single VOD (27 animals) or sufficient Cook fibered stainless steel coils to achieve angiographic occlusion (6 controls). Test animals were assigned to undergo angiography at 1 week (n=11), 1 month (n=6), 3 months (n=6), or 6 months (n=4). Two control animals were assigned to angiographic follow-up at 1 week, 1 month, and 3 months. Test and control animals were euthanized at each time point to explant occluded vessels for histological analysis. Study endpoints were device utilization, time to occlusion, postdeployment migration, and persistent angiographic occlusion at 7, 30, 90, and 180 days.

RESULTS

One VOD was deployed in each test animal, whereas a mean 3.3+/-0.8 coils were needed to achieve angiographic occlusion in the 6 controls (p<0.001). The time to occlusion was significantly shorter with the VOD (1.46+/-0.73 versus 5.83+/-1.60 minutes for the coils; p<0.001). There was no evidence of recanalization or filling defects at the site of VOD deployment, while filling defects were seen in 3 of 6 coil-treated controls. The VOD arm showed superior angiographic occlusion versus coils at the 1-week, 1-month, and 3-month angiographic follow-up time points. Histological evaluation showed that the VOD was equivalent to the embolization coils at the 1-week (n=6) and 1-month (n=6) endpoint (100% luminal occlusion). In the 3-month group (n=6), the VOD showed 95% to 100% luminal occlusion versus 90% to 95% in the control animals. In the 6-month group, VOD showed 85% to 95% occlusion.

CONCLUSIONS

The Biomerix VOD appears highly effective and reliable, resulting in significantly faster and longer lasting occlusion compared with fibered stainless steel embolization coils.

A hybrid endovascular procedure to preserve internal iliac artery patency during endovascular repair of aortoiliac aneurysms

PURPOSE

To demonstrate the feasibility of a hybrid endovascular procedure to preserve blood flow in the internal iliac arteries (IIA) during aortoiliac endografting.

TECHNIQUE

When aneurysmal dilatation makes the distal neck in the common iliac artery (CIA) too short for an adequate seal, the CIA bifurcation is exposed via an extraperitoneal approach after endograft deployment. Via an arteriotomy in the CIA, the distal end of the stent-graft is sutured to the CIA bifurcation under direct vision to preserve IIA blood flow. This approach has been successful in preserving IIA blood flow in 5 of 7 endograft procedures; in the other 2, IIA occlusion was a predictable event.

CONCLUSIONS

Direct suturing of an aortoiliac stent-graft to the CIA bifurcation via an extraperitoneal approach is a useful method of maintaining IIA perfusion. However, further study is required to identify patients at high risk of pelvic ischemia who would benefit from such intervention.

Evaluation of patient selection guidelines for endoluminal AAA repair with the Zenith Stent-Graft: the Australasian experience

PURPOSE

To review the patient selection guidelines for endovascular repair of abdominal aortic aneurysms (AAA) using the Zenith Endovascular Graft and establish an order of importance for each criterion.

METHODS

The Zenith Endovascular Graft Research Database was interrogated for information on 238 patients (209 men; mean age 74.9 +/- 0.9 years, range 50-94) treated with a Zenith bifurcated graft from 1994 to 1998. The common complications of endoluminal AAA repair (endoleak, migration, graft occlusion, graft kinking, conversion, and deployment failure) were analyzed to determine any associations with selection criteria.

RESULTS

By 1998, 69% of endograft patients did not meet the recommended guidelines; however, primary and secondary aneurysm exclusion rates were 87% and 94%, respectively. Over a median follow-up of 13.4 months (interquartile range 2.8-24.0), 38 (16%) patients developed 28 (74%) early and 10 (26%) late type-I endoleaks. The endoleak rate in necks < or = 10 mm long was 57% (8/14). Endoleak was associated with a neck contour change >3 mm (p = 0.003) and neck length <20 mm (p = 0.045). The risk of proximal endoleak was 4 times greater if at least one of the proximal neck guidelines was breached; combined guideline deviations of "contour change and large diameter" (p = 0.0004), "contour change and short length" (p = 0.006), "large diameter and short length" (p = 0.01), and "contour change and angle" (p = 0.03) also increased the risk of endoleak. Endograft migration was seen in 10 (4.2%) cases; only neck diameter >28 mm (p = 0.0024) was associated with this complication.

CONCLUSIONS

Proximal neck contour, length, and diameter are the most important criteria in terms of endoleak development. Breaching the proximal neck length criterion resulted in a 4-fold increase in endoleak, and combined deviations from the guidelines multiplied the effect. Necks < or = 10 mm long are unsuitable for the standard Zenith graft.