Balloon embolization of the internal iliac artery before aneurysm endograft deployment

Stent-Graft Treatment of Pseudoaneurysms and Arteriovenous Fistulae in the Carotid Artery

The purpose of this study was to assess the safety and efficacy of stent-graft placement in the management of arteriovenous fistulae (AVF) and pseudoaneurysms (PAs) involving the carotid artery (CA).

Twenty-two patients (16 men, 6 women) with a CA AVF ( n = 5) or PA ( n = 17) owing to a gunshot or stab wound, carotid endarterectomy, blunt trauma, a tumor, spontaneous dissection, or a central venous catheter were treated with percutaneous placement of stent grafts. The patients presented with tumor, bruit, headache, mouth and tracheostomy bleeding, transitory hemiparesis, seizure, or stroke. Diagnoses were made by using computed tomographic angiography (CTA) and digital subtraction angiography. Fourteen lesions were in the common CA; eight were in the internal CA. Homemade devices and stent grafts from a variety of manufacturers were employed. Follow-up evaluations included clinical, CTA, and Doppler ultrasound assessments.

All patients had resolution of the PA or AVF. In one patient with a large petrous PA, acute occlusion of the CA developed after placement of three balloon-expandable stent grafts, but there were no neurologic complications because the circle of Willis was functional. During follow-up ranging from 2 months to 13 years, asymptomatic 90% stenosis owing to stent compression was observed on Doppler ultrasound and angiographic examinations in a patient with an autologous vein–covered stent graft in the internal CA. Three other patients died of causes unrelated to stent-graft placement. In all other patients, the stent graft remained patent.

Our results indicate that stent grafting is an acceptable alternative to surgery in the treatment of AVF and PAs in the CA.

Patient-Specific IVR Endovascular Simulator with Augmented Reality for Medical Training and Robot Evaluation

Endovascular intervention using interventional radiology (IVR) is most commonly used in cerebralvascular treatment. Medical imaging such as digital subtraction angiography (DSA) and vascular mapping make vasculature and catheters easier to read from fluoroscopy during endovascular intervention. We propose simulating IVR using augmented reality, reproducing fluoroscopic images and a patient-specific blood vessel model without X-ray imaging. The advantages of the patient-specific vascular model reproducing the human vasculature lumen with 13 μm resolution include 1) a realistic “feel,” 2) excellent tool behavior simulation during intervention, and 3) surgical training alternative to physician training in-vitro. Simulated fluoroscopic images are created in two steps: First, the blood vessel model refraction index is matched to surrounding glycerin solution to conceal the vascular model, making the silicone vasculature appear human as seen in endovascular intervention. Second, an augmented reality (AR) environment is created using image subtraction and overlap, making model-based endovascular simulation more understandable for catheter use and fluoroscopy use and reading.

Internal Iliac Artery Embolization before Endovascular Repair of Aortoiliac Aneurysms with a Nitinol Vascular Occlusion Plug

PURPOSE

To evaluate the acute and midterm effectiveness of a novel vascular occlusion device for embolization of the internal iliac artery (IIA) before endovascular repair of aortoiliac aneurysms.

MATERIALS AND METHODS

Between March 2005 and April 2006, nine men (mean age, 75 years +/- 5; range, 66-83 y) with aortoiliac aneurysms underwent bifurcated endovascular stent-graft procedures. All these patients were referred specifically for embolization. Pre- and perioperatively, eight patients underwent unilateral embolization and one underwent bilateral embolization of the IIA to prevent type II endoleak. Via a contralateral femoral approach with a 6-F or 8-F sheath, the embolization procedure was performed with an Amplatzer Vascular Plug, a self-expandable cylindrical device consisting of a nitinol-based wire mesh. Technical success, clinical outcome, and complications were evaluated. Follow-up at 3, 6, and 12 months was performed with clinical and radiologic examinations.

RESULTS

IIA embolization was technically successful in all cases and no procedure-related complications occurred. Imaging at discharge and at 3-, 6-, or 12-month follow-up was accomplished in all nine patients. Control computed tomography and magnetic resonance angiography did not reveal retrograde perfusion of the aneurysmal sac, ie, type II endoleak. Three of nine patients (33.3%) reported symptoms of buttock claudication that did not resolve completely. Clinical symptoms such as bowel ischemia or sexual dysfunction were not observed.

CONCLUSIONS

The midterm results of this study suggest that preoperative IIA embolization with a nitinol vascular occlusion plug during endovascular treatment of aortoiliac aneurysms is safe and effective.

Amplatzer Vascular Plug to occlude the internal iliac arteries in patients undergoing aortoiliac aneurysm repair

PURPOSE

The purpose of this report is to evaluate the use of conventional coils and the Amplatzer Vascular Plug, a type of nitinol-based self-expanding device, to occlude the internal iliac artery in patients undergoing aortoiliac or common iliac aneurysm endograft repair, or both.

METHODS

Between August and December 2004, in preparation for endograft repairs of aortoiliac or common iliac artery aneurysms, or both, at a community hospital system, five patients underwent the occlusion of the internal iliac artery with an Amplatzer Vascular Plug to prevent endoleak. During the preceding 12 months, the conventional coil embolization of the internal iliac artery was used for the same purpose in 10 patients.

RESULTS

In five patients undergoing the Amplatzer Vascular Plug occlusion of the internal iliac artery, precise deployment at the origin of the artery was achieved. Complete and precise occlusion was confirmed angiographically, and only one device was used for each internal iliac artery. Two patients reported mild buttock claudication 2 weeks after occlusion, which resolved completely by 6 and 8 weeks, respectively. A type II endoleak from the inferior mesenteric artery developed in one patient. In the previous 10 patients, 11 internal iliac arteries were treated with conventional coils. Subsequent repeat coil embolization was required for three patients. The procedural complications in this second group included one case of coil embolization into the superficial femoral artery and one into the common iliac artery; both errant coils were retrieved successfully by endovascular techniques. An average of 7 +/- 3.4 (mode of 5) coils were used for each internal iliac artery. Three cases of buttock claudication occurred after the unilateral internal iliac artery occlusion in this group and did not resolve. No evidence of ischemic bowel, buttock necrosis, or sexual dysfunction was observed in either group. The estimated average cost to occlude one internal iliac artery was 375 dollars for Amplatzer Vascular Plugs and 3,500 dollars for conventional coils.

CONCLUSIONS

The Amplatzer Vascular Plug allows for a cost-effective method to occlude the internal iliac artery in patients undergoing endograft repairs of aortoiliac aneurysms. The use of a single device with a precise placement at the origin of the artery minimizes cost and avoids ischemic complications.

Internal Iliac Artery Coil Embolization in the Prevention of Potential Type 2 Endoleak after Endovascular Repair of Abdominal Aortoiliac and Iliac Artery Aneurysms: Effect of Total Occlusion versus Residual Flow

PURPOSE

To evaluate whether the presence of type 2 endoleak after internal iliac artery (IIA) coil embolization in patients with residual antegrade flow through the coils is more frequent than in patients who presented with total occlusion of the IIA after embolization.

MATERIALS AND METHODS

Records were reviewed of 45 patients who underwent unilateral (n = 37) or bilateral (n = 8) IIA coil embolization between 1998 and 2004 for endovascular repair of aortoiliac aneurysms (n = 32), iliac artery aneurysms (n = 12), pseudoaneurysm (n = 1), or distal type 1 endoleak after placement of an aortoiliac stent-graft (n = 8). A total of 53 IIAs were embolized by means of coils and/or microcoils. Computed tomography (CT) was used for follow-up in 40 patients, angiography was used in three, and color Doppler ultrasonography was used in three.

RESULTS

At the end of the embolization procedure, 23 IIAs were occluded and 30 IIAs demonstrated residual antegrade flow through the coils. Control CT demonstrated two type 2 endoleaks after endovascular stent-graft placement resulting from retrograde blood flow into the left IIA main branch via a patent iliolumbar artery. One of these two patients showed residual antegrade flow through the coils at the end of the IIA embolization procedure, and the other patient underwent complete coil embolization of the ostia of the anterior and posterior division but not of the main trunk of an aneurysmal IIA.

CONCLUSION

IIA coil embolization with residual antegrade flow through the coils causes no greater incidence of type 2 endoleak after aortoiliac or iliac stent-graft placement. However, care must be taken in case of a proximal postostial origin of the iliolumbar artery on the IIA, which may cause type 2 endoleak if not embolized.

Internal iliac artery embolization with bilateral occlusion before endovascular aortoiliac aneurysm repair-clinical outcome of simultaneous and sequential intervention

PURPOSE

To retrospectively evaluate the clinical outcome of patients after simultaneous or sequential internal iliac artery (IIA) embolization for bilateral IIA occlusion.

MATERIALS AND METHODS

Sixteen patients (65-88 y; mean, 75.6 y; two women), 11 with aortobiiliac aneurysms, three with bilateral common iliac artery (CIA)/IIA aneurysms, and two with unilateral CIA/IIA aneurysms, underwent IIA occlusion before endovascular aortoiliac repair. Eight patients underwent simultaneous bilateral IIA embolization before endovascular aortic repair (EVAR). Eight patients had sequential bilateral IIA occlusion. The outcome was assessed by clinical follow-up.

RESULTS

There were no severe ischemic complications such as buttock necrosis or acute bowel, bladder, or spinal cord ischemia. Early ischemic complications occurred in 25% (buttock/thigh claudication, n = 3, 18.8%; and sexual dysfunction, n = 1, 6.2%) and had an onset not later than 6 months after intervention: buttock claudication resolved (n = 2) or persisted after aggravation by inferior mesenteric artery embolization for type II endoleak (n = 1). Impotence in a fourth patient persisted. The ischemic complication rate after 6 months was 30% (three of 10) because of a fifth patient who developed ischemic colitis with aggravation of ischemic heart disease after 15 months. The mean follow-up duration was 19.7 months. Patients with simultaneous embolization had a lower complication rate than those with sequential embolization (one of eight [12.5%] vs four of eight [50%], respectively).

CONCLUSIONS

IIA embolization for bilateral IIA occlusion can be performed with a complication rate comparable with results of previous studies of unilateral IIA embolization. Chronic buttock claudication may be aggravated by embolization of aortic side branches. Late complications can have an insidious course and be initiated by low-output cardiac failure. Bilateral IIA occlusion is recommended only in patients who are considered unfit for aortic surgery.